Me: When I was on the All About Height Board from the Network54 forums, I found that the posters were talking about this Doctor from India, the New Delhi area named Dr. Bagga who seems to claim that he has managed to develop and create a type of herbal formula system which can help at least kids grow taller.

The website for Dr. Bagga is called HerboHeight.com. Although the main page is up, most of the links are dead, probably because the site was created more than 10 years ago. There is a discussion on this guy on the website ABCHomeopathy.com. the sad fact is that this guy is only briefly mentioned and the post titled “Increase Your Height” has over 1000 replies and posts, with many people wanting to grow taller. They also talk about him on the New Height Increase Message Boards on Network54. This post was made in 2005 and the poster says that the therapy did not increase his height at all. From this link source HERE, I found this Dr.’s Contact Information. I would assume this is really old information so his person’s office might not be there anymore.

Herbo Height Therapy
Clinic of Dr. O.P. Bagga providing herbal treatment for increasing height. Claims effectiveness even after 35 years age. 
Address: Bazar Lal Kuan ( Opp. Koocha Pandit – 1st Floor ) Delhi – 110006. Phone : +91 – 11 – 23262426. Email:drbagga@herboheight.com
http://www.herboheight.com

[Note: Like I have said always with these products, there is no way to tell if the height increase that comes after taking such supplement or doing the technique was because of the actual product or from actual natural height growth.]

In my searching, I actually found a clipping in an old magazine on this Dr. Bagga’s Herbo Height increease therapy. The clippings are on the left. They are taken from Google Documents source link HERE  which is the April 2002 edition of magazine “Competition Science Vision” pg. 155.

A thing to note is that I don’t have much hope for using this therapy to help adults gain the increased height they want, but this therapy might be useful in giving us another clue in the puzzle on putting everything together.

When I googled the name “dr. o.p. bagga” into google what I found was that there was a few forum discussions on the possibility of his therapy working.

The first thing I notice is that this advertisment section is placed in many of the old magazines. it was in many of the monthly editions of the Competition Science Vision magazine, from 2001 and 2002, to even 2005. I think at this point, we can mostly conclude that this “Dr.” was running a scam since if he has to take out advertisement in a children’s or teenager’s magazine, they are really just selling something not credible.

Me: The Last resource link I wanted to cite was from the All ABout Height Boards HERE. One of the poster writes..

I found this youtube video (source link HERE) and I thought the infomercial was well done.

I remember trying to make the heels in my shoes thicker years ago and I do notice that my confidence or state of mind improve from wearing taller shoes and looking taller.

If you are willing to wait a while (like a few years while the science and research catches up) then I might suggest for the guys to go with these really nice looking lifts aka height increasing dress shoes. I think the main selling point with this brand of thick heeled shoes is that they are more comfortable than some others. They say the insoles are ergonomically designed.

[Marketing Lie Alert! – The issue with this product is that although they claim the shoes are supposed to make you appear to be 10 cm taller, the sellers are very deceptive in not making the note that the 10 cm increase is from not wearing any shoes, but not compared to a person wearing average heel thickness shoes. If this was the case, the claim would be that the shoes only increase in appearance height of 6 cms, not 10 cm, since most dress shoes already have about a 1.25-1.50″ (3-4 cms) . This is a sort of a marketing trick to make the product seem better than it really is]

Me: Somehow while I was looking on Youtube at another recently talked about device, the magnetic powered foot stimulating device, I found another youtube video which is promoting a oral intake type of pill which is supposed to help the still growing and developing individual gain more height.

If you watch the video below, which is about 2 and a half minutes long, you can see that the English Speaking person who uploaded the video is mocking the Chinese Infomercial. I would assume most of the regular visitors who come to this website would just make a quick claim that the product is a scam and won’t work, which I agree with, but that does not mean that such a product should not be studied. There are a few other link source like HERE and HERE (PinoyExchange.com) on the Zenith Grow Taller product.

When I was looking through the ingredients of a recent post on the possibility of using Ayurvedic medicine to increase height, what I found was that many of the ingredients in the compound mixture has real medicinal properties and seemed to be related to L-Dopa and have anabolic qualities. This shows that at least some of the ingredients have real scientific studies backing up their claim.

What I would actually like to do for these infomercial pills sold in China is see what they are really made of and look for  any unique ingredients. From the link below, these are the ingredients….

Q : What is the content of the calcium tablet? How should I take the tablet?

A : Oyster Shell Power, Bone Meal Powder, Rose Hips Powder, Guar Bean Gum, Hydroxypropyl Methl Cellulose, Magnesium Stearate and Vitamin D3. Take one tablet daily and your body will absorb the calcium in your food intake. The Taiwan’s health authority approval number is 8602629.

The directions state this…

The main element leading to the bone cells division is NGF (Nerve Growth Factor). Therefore, the only effective means to gain height is to once again cause the bone to release large amount of NGF is to stimulate the pituitary gland to release growth hormone.

It seems that besides the capsule pills, you will also have to put a type of pad with NGF in it on your back of neck for 24 hours a day. They say that this Zenith Height product is approved by the FDA and ARP as well as some Taiwan organization but what do I know? I don’t think anyone is going to go through all the hassle to see if these guys are really being honest about the FDA approval. Even if the FDA approves of it, the FDA does not test for product feasibility, only for safety.

Q: What are the ingredients of Zenith Grow?

A: Natural coral calcium with vitamin D3 and several mineral substances, extracted and purified. (To find out more on coral calcium, you could check out link below) http://www.familyhealthnews.com/48.html

What I am seeing is that there is a use of Vitamin D3 and some form of Calcium Carbonate (which is a calcium supplement) from the Coral calcium or Oyster Shell Powder.

From PubMed study link HERE… I learn that “Nerve growth factor (NGF) is a neurotrophin that is essential for survival and differentiation of neuronal cells” and “Nerve growth factor (NGF) induces neurite outgrowth and differentiation in a process that involves NGF binding to its receptor TrkA and endocytosis of the NGF–TrkA complex into signaling endosomes.”

Other directions involve putting this pad on your neck after you shower each day. There is supposed a type of heat that comes from it and may cause itching and irritation. One of the posters named Heng paid almost $1200 for all the products, which include the pills, the pad (you place 15 cm below the shoulder level), a mini massager for the knees, and insoles to wear (like KIMI and YOKO). So far they have never answered the other posters on whether they grew or not.

Conclusion: This product which seems to either come from Malaysia, Taiwan, or China has two main active ingredients, Calcium and Vitamin D3. This could theoretically help a little bit for the still growing individual. What is interesting about this product is that they claim the NGF (Nerver Growth Factor) comes from the pituitary gland, which I am not sure is true or not. However, the fact that this product claims that NGF, not HGH does the height increase gets me curious on the effects of NGF on the human body.

[Note: There is also a forum post on the Gloxi height increase product with the Zenith Growth Program HERE and the one of the posters clearly say that both products are hoaxes.]

When I did a search on google for the term “Zenith grow pills” what I found was that there was a post from the All About Height Boards or Network54 Boards years ago (11 years to be exact!!) about the feasibility of using this Zenith Grow Taller Pill. I found this testimonial posted from this link HERE…

Me: So this person said that they did grow in height only after spending $1200! That is really expensive. You are supposed to get 3-5 cm after one month (or 1 inch) and 5-8 cm after 2 months (or 2-3 inches).

The Youtube video link is from HERE

Something that has been really going through my thoughts recently is the possibility that the real limiting part of a possible non-invasive bone lengthening technique may not be the bones themselves, but the muscles and ligaments surrounding the bones.

This is the theory I propose the reader to think about.

Most ideas created to increase height works for the legs, and specifically the long bones in the legs. We know that the bones are surrounded by another main source of connective tissue, the muscles and ligaments. As for the ligaments, they are usually thin, strong connective tissue that are spread out in pattern. The muscles are instead bundled together to make them even stronger than the ligaments. We know from bodybuilding theory that even thought the muscles are strong, we can still tera the muscles and let them regrow and that is what causes muscle build up. In terms of elasticity, the muscles are obviously more elastic than the bones. From a common sense point of view, we say that the real reason we don’t get higher is because our bones are not elastic so we can’t stretch vertically up. And that is a reasonable arguement.

However, when we are talking about finding a non-invasive way to increase height, we find that often the reason the technique is so hard to achieve is because of the muscles covering the bone. To have any effect on the bones, we often have to apply some type of external stimuli through the muscle to the bone. And to do that besides a type of “action through a medium” technology (ie X.-Ray, radiation, ultrasounds, shockwaves, electrical fields), we almost always have to cut through the muscles using a solid That means that by definition, we are being non-invasive for almost all of our ideas.

What the LSJL method gets right is that you are doing something to the bone that is not really surrounded too much by muscle. Sure, there is the few layers of skin that cover the epiphysis but overal, the is not type of stimuli through the muscle to reach the bone.

I can promise to the readers right now that I can already devise 3 theretically sound probable ways to lengthen the actual long bones, however ,my ideas require that the covering tissues of the bone to be penetrated, lacerated, and distracted so that we can reach the bone and touch device or implant to the actual bone surface to have an effect. The main issue that makes it very difficult for me to devise a real non-invasive method is not the bone, but the surrounding tissue, the muscle, the cartilage, and the ligaments.

The problem then is that I am not a surgeon, much less orthopedic surgeon so I have no right to cut through human muscle to work on bone. Even if I propose a completely valid idea on how to lengthen the bone, there won’t be many orthopedic surgeons who would take my advice and be willing to integrate it into their practice.

In my research, there are many many ideas already out on how to lengthen bone, but only the bone. The muscle is often not considered, but when the actual technique has to be executed, then the people who have to do it, almost always a surgeon, have to consider the issue of dealing to muscle.

This post is one of the final studies which sort of culminates the type of research where we look at the ability modern science and technology have been able to come to find a way to repair, regenerate, and completely grow cartilage to be used for repair and implantation and transplantion using the gene therapy method.

Note: The study below is missing the references and citations, which is critical to possibly find other critical studies. I intentionally left out the really long list of references. Please use the link below to find what is needed.

Analysis & Interpretation

The study itself was to summarize the multiple ways medical researchers have tried to use gene therapy to heal articular cartilage defects. As noted from previous posts, the two main ideas was always to either inject the adenoviral vector with the right type of growth factors inside directly to the defect area or close to it, or to go the second path to first inject the vector into progenitor cells which will be altered to express more chondrogenic differentiation. The stem cells are then injected and implanted to the cartilage area. While the main issue had been that the cartilage that was formed was fibrocartilage, the noticing of hyaline cartilage makes the venture seem even more likely to have great effectiveness.

The researchers note that any damage to articular cartilage means that it becomes hard to repair. The articular cartilage has a strong resistance from becoming vascularized, which suggest that if a damage does occur, there is not blood vessels to transport the needed tissue repair elements needed to the right area. It seems that nutrients in the hyaline cartilage matrix might actually be diffused to the chondrocytes. When there is a partial defect, that area does not get healed from there being no way for the healing elements to reach the ara of the defect. When there is a more serious defect in the articular cartilage, where the fracture or defect goes deeper and actually makes a cut or puncture in the chondral bone in the subchondral layer, the  result is cartilage forming elements do come out of the inside of the bone but the cartilage they form is fibrocartilage, which has collagenous fibers that are not organized like hyaline cartilage.

When however not even the fibrocartilage is formed, that lead to pain for the subject so the medical professional might choose to stimulate the fibrocartilage formation process by doing a surgical technique known as abrasion anthroscopy, drilling, or microfracture surgery. The technique is reasonable effective and successful in removing the pain however it is well known that fibrocartilage is just not as good as the hyaline cartilage in the articular cartilage. There is much more Collagen Type 1 (while we are looking for Collagen type 2), there is more disorganization, etc. The result is that medical researchers have tried transplanting periosteum, perichondrium, and osteochondral parts to see what would happen .The short term effects is good in showing effectiveness in producing the hyaline cartilage they are looking for but the long term effects are not well known. It is suspected that one of the major problems is that there is not enough say periosteum or perichondrium available if a articular cartilage defect becomes too large.

The researchers seem to solve this problem by stating ,” Therefore, the autologous chondrocyte transplantation (ACT) procedure has been used clinically since 1987 in combination with a periosteal cover to treat chondral or osteochondral defects of the knee with good clinical results”

The top phrase means that the main way the researchers do it is to put the chondrocytes they get from an explant into a solid matrix (like a scaffold) and then implant the matrix which has the chondrocytes inside. Like one will learn from the Wikipedia article on the basic steps of Tissue Engineering, this is what tissue engineering is completely about. The result is that the symptoms in terms of pain does go away, at least for a short time while there is the autologous chondrocyte implant. However, again we see that the formation of really durable hyaline cartilage tissue is hard to form.

The whole point of the researchers can be summed up by their next sentence, “Therefore, tissue engineering approaches are being aggressively investigated in an effort to engineer cartilage in vitro to produce grafts to facilitate regeneration of articular cartilage in vivo“

The steps the researchers almost always goes through is…

1. The original chondrocyte cells or progenitor mesenchymal stem cells are taken from some enzymatic digestion process or an outgrowth culture.
2. The cells are put in a culture where they are slowly grown to increase in number until a cell colony (or sufficient cell number density) is formed.
3. The cells are then injected in a a scaffold or matrix because you need something to hold the chondrocytes in place for a 3-D space.
4. The matrix is then injected with growth factors to further grow the cell numbers and cartilage formation.
5. The matrix is then implanted into the cartilage defect.

The problems on why this general step by step procedure don’t seem to work well in new hyaline cartilage formation are…

• insufficient differentiation
• loss of transplanted cells or tissues
• matrix destruction
• integration failures

In the next section the researchers show that all of these problems which have been inhibiting the formation of new hyaline cartilage has been themselves been inhibited or have their inhibitory effects mostly stunted. There are now…

• morphogens and transcription factors that promote differentiation along chondrogenic lineages – thus solving the differentiation problem
• growth factors that promote matrix synthesis – thus solving the matrix destruction problem
• inhibitors of osteogenic or hypertrophic differentiation – it helps reduce the integration failures since it prevents osteogenic tissue from appearing, letting the chondrogenic tissues have a chance to form before being cut off by the bone making elements.
• antagonists that inhibit apoptosis – thus solving the loss of cells problem
• senescence or responses to catabolic cytokine – which solves the loss of tissues and cells problem

However even this new ideas and ways have their own set of problems. Those problems would be…

• delivery problems
• the limited half-life of many of the proteins that might be injected in vivo
• the difficulty in administration of the elements at a high enough concentration and for a long enough time for effectiveness
• the injected material can also affect non-targeted tissue and organs.

As a consequence, the researchers felt that it would be much more effective in use a gene therapy approach. The best approach would be to be able to alter the genetics of the chondrocytes close to the defect so that any type of hyaline cartilage regeneration will be more natural instead of trying to embed a transplant.

From Table 1 there will be a list of candidates to be put into a vector including all the types of TGF-Beta, IGF-1, BMPs, FGFs, and EGFs. The IHH, SHH, SMAD, and Sox genes are also named as potential regulators for chondrogenesis. Some of these components can be combined together to have a more effective regulatory role.

“There are many strategies that can be used to deliver exogenous cDNAs for the treatment of diseased or damaged cartilage….A key component for any gene therapy application is a vector that efficiently delivers the cDNA of interest to the target cell, and enables transgene expression of a suitable level and duration to affect the desired biological response. Furthermore, an understanding of the natural behavior of the target cell, such as its half-life, rate of division, and infectability with the vector are also essential to the effectiveness of the procedure.”

The basic principle of gene therapy is explained again. You put the cDNA into a vector, you inject the vector into a cell to change the way the DNA inside the cell to express genes in terms of types and amount. So far the ways gene therapy has been used in tissue engineering range from being the most complicated to being the simplest.

As we have said before, there is two main ways for vector use in intra-articular cartilage repair, the in vivo method and the ex vivo method. The in vivo method means putting the vector directly on the defect. The ex vivo method means putting the vector into cells first , and then transferring the cells to the defect. Which type of method to use depends on the gene being delivered and the vector to be used.

After this, the researchers would go into explain the 4 main ideas expressed in the diagram to the left.

They are …

Gene transfer to the synovium – add the vector to the synovium cells

Gene transfer to the cartilage defect – add the vector to the cartilage defect area for local trans-expression of the desired results from the chondrocytes in the area

Gene transfer to the chondrocytes – add to chondrocytes

Gene transfer to the mesenchymal stem cells – Note what the researchers said about the MSCs approach, “However, a successful use of MSCs to aid cartilage repair by means of generating a stable hyaline-rich cartilage repair tissue in vivo, likely requires the efficient delivery of factors to stimulate MSCs toward chondrogenesis, and maintenance of an articular cartilage phenotype without ossification, fibrinogenesis, or inflammation”

Implications For Height Increase

I think it is time to move our scope of analysis out more and see the forest and not the trees. We’ve gone really technical and deep into the details of this idea of gene therapy for intra-articular cartilage repair and we have to ask ourselves how we can use it to increase height. It has come to my awareness that the key to being able to say create a pseudo-growth plate after the natural growth plates close was to study the current medical science on how to regrow cartilage, but more specifically the hyaline cartilage. The best idea would be to create new epiphyseal cartilage, but the stacking nature of the chondrocytes to get the columns is something I still haven’t found much details on. There was only one study which showed that a chemical compound seems to result in the columnar arrangement of the chondrocytes. At this point I am just trying to study more on the way gene therapy works, on how tissue engineering works, and how the articular cartilage can possibly be regenerated after defects are formed. If this area of research is understood as a deep enough level then we can propose a way to using just a few injections get a part of the long bones to start creating hyaline cartilage. My theory is that as long as we can get hyaline cartilage (and maybe even fibrocartilage0 to be formed in a way that makes the tissue go completely around the cortical bone area, then we can use other methods like mechanical loading to get the bone to be lengthened with relative ease.

I had proposed many idea in the past on how to alter the bone and the cartilage in the long bone for increased length before using ideas like autologous chondrocyte transplantations, but the ideas were still only relatively vague and the details were missing. With this study I would be able to develop a more coherent and scientifically sound idea on how to use tissue engineering and gene therapy for cartilage regeneration for longitudinal increase in the long bones.

Note: The full study is copy and pasted below for reference if one desires to see the original paper.

Published in final edited form as:

Injury. 2008 April; 39(Suppl 1): S97–113.

doi:  10.1016/j.injury.2008.01.034

PMCID: PMC2714368

NIHMSID: NIHMS93905

Concepts in Gene Therapy for Cartilage Repair

Andre F. Steinert,¹ Ulrich Nöth,¹ and Rocky S. Tuan²

Summary

Once articular cartilage is injured, it has a very limited capacity for self-repair. Although current surgical therapeutic procedures to cartilage repair are clinically useful, they cannot restore a normal articular surface. Current research offers a growing number of bioactive reagents, including proteins and nucleic acids, that may be used to augment different aspects of the repair process. As these agents are difficult to administer effectively, gene transfer approaches are being developed to provide their sustained synthesis at sites of repair.

To augment regeneration of articular cartilage, therapeutic genes can be delivered to the synovium, or directly to the cartilage lesion. Gene delivery to the cells of the synovial lining is generally considered more suitable for chondroprotective approaches, based on the expression of anti-inflammatory mediators. Gene transfer targeted to cartilage defects can be achieved by either direct vector administration to cells located at or surrounding the defects, or by transplantation of genetically modified chondrogenic cells into the defect. Several studies have shown that exogenous cDNAs encoding growth factors can be delivered locally to sites of cartilage damage, where they are expressed at therapeutically relevant levels. Furthermore, data is beginning to emerge indicating, that efficient delivery and expression of these genes is capable of influencing a repair response toward the synthesis of a more hyaline cartilage repair tissue in vivo. This review presents the current status of gene therapy for cartilage healing and highlights some of the remaining challenges.

Introduction

The application of gene transfer to articular tissues was pioneered by Evans and co-workers, as a means to treat arthritis [46,49]. Initial encouraging experiments in animal models using retroviral-mediated gene delivery formed the basis for a clinical trial to evaluate the safety and feasibility of using gene therapy for rheumatoid arthritis [46,49,59-61,148]. The study was completed without incident; the procedure was well-tolerated by the nine participants, and intra-articular gene transfer and expression was observed in all joints treated [46,49]. The relative success of these studies suggests that this technology may have application in treating a number of articular disorders for which current treatment modalities are unsatisfactory. Compared to the treatment of chronic or genetic diseases, where likely a lifelong expression of a corrective transgene is required, the use of gene transfer techniques to facilitate musculoskeletal tissue repair offers perhaps an immediate opportunity for a clinical application of gene therapy, as it may only require transient, localized expression of a specific transgene product. Whereas good success has been achieved by gene transfer to bone healing [9], augmenting the repair of focal articular cartilage defects by gene transfer has not been straightforward. Current research indicates that the design of a successful genetic approach for cartilage repair includes a refined strategy of gene delivery that meets the complexities of treating this tissue. This review aims to summarize some of the basic principles of cartilage injury and regeneration, and comments on the pros and cons of recent gene therapy approaches to repair, as well as future challenges.

Cartilage injury and limitations of current treatments

Hyaline articular cartilage is a highly specialized tissue that protects the bones of diarthrodial joints from forces associated with load bearing, friction and impact. Although a remarkably durable tissue, once articular cartilage is injured, it has very limited capacities for self-repair. In partial thickness defects, where a lesion is wholly contained within the articular cartilage, there is no involvement of the vasculature. Consequently, chondroprogenitor cells in blood and marrow cannot enter the damaged region to influence or contribute to the reparative process. Resident articular chondrocytes do not migrate to the lesion, and production of a reparative matrix by these cells does not occur. As such, the defect is not filled or repaired and essentially remains permanently [21,80]. Full thickness cartilage injuries result in damage to the chondral layer and subchondral bone plate, causing rupture of blood vessels, and hematoma formation at the injury site. In this case, a repair response is initiated that results in the formation of a fibrocartilage repair tissue within weeks [21,80].

In focal cartilage defects, where a stable fibrocartilaginous repair tissue has not formed, and patients are suffering clinical symptoms such as pain and swelling, surgeons aim to promote a natural fibrocartilaginous response, by using marrow stimulating techniques, such as abrasion arthroplasty, Pridie drilling, or microfracture. These procedures are cost effective and clinically useful, as patients often have reduced pain and improved joint function, and are therefore generally considered as first-line treatment for focal cartilage defects [22,121,122,161,162]. However, fibrocartilage has inferior mechanical and biochemical characteristics compared to normal hyaline articular cartilage. It is poorly organized, contains significant amounts of collagen type I, and is susceptible to injury. The inferior repair matrix breaks down with time and loading, which ultimately leads to premature OA [21,80]. Therefore, as outlined in other articles of this issue, the aim of modern therapeutic techniques is to achieve a more hyaline-like cartilage repair tissue by transplanting tissues or cells. Tissue transplantation procedures such as periosteum, perichondrium, or osteochondral grafts have shown positive short term results for a number of patients, but the long term clinical results are uncertain, with tissue availability for transplant being a major limitation, especially in large cartilage defects [19,22,23,71,80]. Therefore, the autologous chondrocyte transplantation (ACT) procedure has been used clinically since 1987 in combination with a periosteal cover to treat chondral or osteochondral defects of the knee with good clinical results [20,121,144,145]. Modern modifications of this procedure include embedding chondrocytes in a three dimensional matrix before transplantation into cartilage defects [15,114,123]. Despite these advances, most surgical interventions only result in improvement of clinical symptoms, such as pain relief, but none of the current treatment options has regenerated long-lasting hyaline cartilage repair tissue yet [22,80,121,144]. Therefore, tissue engineering approaches are being aggressively investigated in an effort to engineer cartilage in vitro to produce grafts to facilitate regeneration of articular cartilage in vivo. In most cases, cells are harvested by enzymatic digestion or outgrowth culture, which are thereafter extensively expanded in culture. The cells are then seeded onto various biologically compatible scaffolds, and cultured in the presence of a specific cytokine or growth factor, or a cocktail of bioactive factors. However, despite promising in vitro data with several approaches, a significant improvement compared to current cartilage repair modalities, has yet to be achieved. Many challenges thus remain for successful cell-based cartilage repair approaches to form hyaline repair tissue in vivo [23,80,92,177]. Impairments of hyaline neo-cartilage formation is likely due to a number of reasons, including insufficient differentiation, loss of transplanted cells or tissues, matrix destruction and integration failures, which all can occur due to various reasons.

Candidate gene products

In recent years, several factors have been identified that might be functional in augmenting different aspects of cartilage tissue repair. Of particular interest are morphogens and transcription factors that promote differentiation along chondrogenic lineages, growth factors that promote matrix synthesis, inhibitors of osteogenic or hypertrophic differentiation, antagonists that inhibit apoptosis, senescence or responses to catabolic cytokines (Table 1). Several of these substances have shown promise in animal models of cartilage repair and regeneration, but their clinical application is hindered by delivery problems [103,164,171]. Due to the limited half-lives of many proteins in vivo, they are particularly difficult to administer to sites of cartilage damage at therapeutic concentrations and for sustained periods of time. Localized delivery of these agents without involvement of non-target organs has also proven to be problematic [164,171]. We suggest that these limitations may be overcome by adapting appropriate gene transfer technologies. In particular, it should be possible to develop techniques for transferring therapeutic genes encoding the necessary gene products to cells at the sites of injury or disease, for sustained local expression at high levels with minimal collateral exposure of non-target tissues [164,171]. In this manner, the proteins of interest are synthesized locally by cells and are presented to the microenvironment in a natural fashion. Furthermore, recombinant proteins produced by overexpression in bacteria may have altered activity, since they may not be similarly modified post-translationally as when synthesized by a mammalian cell [113].

Table 1

Classes of gene products that aid cartilage repair

The list of potentially useful cDNAs for cartilage repair (Table 1) comprises members of the transforming growth factor (TGF)-β superfamily, including TGF-βs 1, 2, and 3, several of the bone morphogenetic proteins (BMPs), insulin-like growth factor (IGF)-1, fibroblast growth factors (FGFs), and epidermal growth factor (EGF), among others (reviewed in [74,103]). Other secreted proteins, such as indian hedgehog (IHH) or sonic hedgehog (SHH), play key roles in regulating chondrocyte hypertrophy [185], and may also prove to be beneficial for modulating the chondrocytic phenotype of grafted cells. Another class of biologics that may be useful in cartilage repair is transcription factors that promote chondrogenesis or the maintenance of the chondrocyte phenotype. SOX9 and related transcription factors like L-SOX5, and SOX6 have been identified as essential for chondrocyte differentiation and cartilage formation [98]. Signal transduction molecules, such as SMADs, are also known to be important regulators of chondrogenesis [76]. As these molecules function completely intracellularly, they cannot be delivered in soluble form, and gene transfer might be the only way to harness these factors for repair. Alternatively, delivery and expression of cDNAs encoding specific extracellular matrix (ECM) components such as collagen type II, tenascin, or cartilage oligomeric matrix protein (COMP), may also be used to support production and maintenance of the proper hyaline cartilage matrix [37].

Prevention or treatment of cartilage loss may also require the inhibition of the actions of certain pro-inflammatory cytokines, such as interleukin (IL)-1 and tumor necrosis factor (TNF)-α, as these are important mediators of cartilage matrix degradation and apoptosis after trauma and disease. Therefore, anti-inflammatory or immunmodulatory mediators, such as interleukin-1 receptor antagonist (IL-1Ra), soluble receptors for TNF (sTNFR) or IL-1 (sIL-1R), IL-4 or IL-10, inhibitors of matrix metalloproteinases, and others may be administered to effectively reduce loss of repair cells and matrix [148].

Inhibitors of apoptosis or senescence, such as Bcl-2, Bcl-XL, hTERT, i(NOS) and others (Table 1), may also be beneficially employed in order to maintain cell populations at the injury site, which are capable of favorable repair responses [39,41]. Different candidate cDNAs might also be administered in combination, especially when favoring complementary therapeutic responses. For example, the combined administration of an anabolic growth factor (e.g. IGF-1) together with an inhibitor of the catabolic action of inflammatory cytokines (e.g. IL-1Ra) has the potential to control matrix degradation as well as to allow partial restoration of the damaged cartilage matrix [73,132].

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Strategies to gene therapy in the repair of articular cartilage

There are many strategies that can be used to deliver exogenous cDNAs for the treatment of diseased or damaged cartilage. For a successful approach, several factors have to be taken into account, including the extent of cartilage pathology, disease processes, and the biological activity of the gene product, among others. A key component for any gene therapy application is a vector that efficiently delivers the cDNA of interest to the target cell, and enables transgene expression of a suitable level and duration to affect the desired biological response. Furthermore, an understanding of the natural behavior of the target cell, such as its half-life, rate of division, and infectability with the vector are also essential to the effectiveness of the procedure. The properties of commonly used vectors in gene therapy applications are summarized in Table 2, and have been extensively reviewed elsewhere [136,168]. Gene-transfer strategies in which these vectors are currently used for cartilage repair, range from those as simple as direct delivery of a vector to a defect, to synthesis of cartilaginous constructs through genetically augmented tissue engineering procedures. We will present below an overview on the properties of commonly used vectors in gene therapy applications (Table 2), and will discuss their use in the context of the different delivery strategies to cartilage defects.

Table 2

Nonviral and viral vectors for orthopaedic gene therapy applications

There are two general modes of intra-articular gene delivery, a direct in vivo, and an indirect ex vivoapproach (Figure 1). The direct in vivo approach involves the application of the vector directly into the joint space, whereas the ex vivo approach involves the genetic modification of cells outside the body, followed by re-transplantation of the modified cells into the body. The choice of which gene transfer method to use is based upon a number of considerations, including the gene to be delivered, and the vector used. In general, adenovirus, herpes simplex virus, adeno-associated virus vectors, lentivirus and non-viral vectors may be used for in vivo and ex vivo delivery (Figure 1, Table 2). Retroviral vectors, because of their inability to infect non-dividing cells, are more suited for ex vivo use. Ex vivo approaches are generally more invasive, expensive and technically tedious. However, they permit control of the transduced cells and safety testing prior to transplantation. In vivo approaches are simpler, cheaper, and less invasive, but viruses are introduced directly into the body, which limits safety testing.

Figure 1

Gene transfer approaches for the treatment of cartilage defects. (A) For in vivo gene transfer, free vector is either injected directly into the joint space, or incorporated into a biologically compatible matrix before implantation into a cartilage defect …

Toward the treatment of damaged articular cartilage, the three primary candidate cell types to target genetic modification are synovial lining cells, chondrocytes, and mesenchymal stem cells.

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Gene delivery to the synovium

The simplest strategy for gene delivery to diseased joints is by direct intra-articular injection of a recombinant vector [60,61]. For this application, the two primary tissues to consider are cartilage and synovium. Within articular cartilage, chondrocytes are present at low density and reside at varying depths within the dense matrix. Because of this, efficient genetic modification of chondrocytes in situhas not been effectively achievable [32,62,170,192]. The synovium, in contrast, is a tissue that is much more amenable to gene delivery. It usually exists as a thin lining of cells that covers all internal surfaces of the joint except that of cartilage, and thus has a relatively large surface area, and is therefore the predominant site of vector interaction. Direct intra-articular injection of vector or modified cells results in synthesis and release of therapeutic proteins into the joint space, which then bathe all available tissues, including cartilage. Using various types of vectors in ex vivo and in vivo approaches, considerable progress has been made towards defining the parameters critical to effective gene transfer to synovium and prolonged intra-articular expression. The effectiveness of synovial gene transfer of various transgenes is well documented in research directed towards rheumatoid arthritis [148]. Ex vivogene delivery to joints has since been taken into phase I clinical trial and shown to be feasible and safe in humans with RA [46,50].

Although most of the work involving direct intra-articular gene delivery has been focused toward the study and treatment of RA, data are beginning to emerge of its potential for treating OA (reviewed in [47]), and to augment repair approaches of focal cartilage defects (Table 3) [31,58,164,171]. For example, encouraging results have been reported for adenovirally delivered IGF-1 or IL-1Ra using animal models for OA and localized cartilage injury [32,54]. While it is possible to achieve biologically relevant levels of transgene expression by both direct and ex vivo gene transfer to synovium, this approach is not compatible with the delivery of certain growth factors. For example, adenoviral mediated delivery of TGF-β1 or BMP-2 to the synovial lining was found to generate joint fibrosis, extreme swelling, osteophytes and cartilage degeneration [8,56,57,120]. Considering these results in the context of cartilage repair, synovial gene transfer may be more suitable for delivering chondroprotective agents rather than strong anabolic transgenes with pleiotropic effects of their products. Many anti-inflammatory cytokines have this property (see Table 1).

Table 3

Therapeutic gene transfer studies to repair focal articular cartilage defects

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Gene delivery to cartilage defects

For the gene-based delivery of certain growth factors or intracellular proteins, a strategy whereby the transgenes are more localized, and the gene products contained within the cartilage lesion, appears to be most prudent. Possibly, the most direct manner by which to achieve this goal is by implantation of a three-dimensional matrix pre-loaded with a gene delivery vehicle into a defect, allowing infiltrating cells to acquire the vector and locally secrete the stimulating transgene products [18,48]. Genetically activated implants have been designed to augment the healing of bones, ligaments and also cartilage [17,34,48,140,141,150]. For example, hydrated collagen-glycosaminoglycan matrices containing adenoviral vectors have been found to promote localized reporter gene expression in vivo, following implantation into osteochondral defects in rabbit knees, for at least 21 days [140]. However, given the usually limited cell supply at the cartilage lesion site, it is not yet known whether this type of approach can induce a sufficient biological response for repair. In order to increase the cellularity of the graft, while preserving the feasibility of the procedure within one operative setting, the genetically activated matrix could be mixed together with autologous cells, which are intraoperatively readily available, e.g. cells from bone marrow aspirates (Figure 1). Such an abbreviated, genetically enhanced tissue engineering approach would thus save time and costs, while avoiding labor-intensive ex vivo culture of cells [48,140]. Their limitation, however, is the lack of control over gene transfer following implantation.

As there are several advantages, gene transfer has mostly been used to augment ex vivo cell delivery approaches for cartilage repair (Figure 1). Such an approach delivers a pure population of cells, that can be selected under controlled conditions; the graft is highly cellular, localizes transgene expression to the injury site without administration of free vector, and there is the possibility for safety testing prior to transplantation. In the context of ex vivo gene delivery to cartilage defects, several experimental studies have been performed, exploring gene transfer to chondrocytes or mesenchymal progenitor cells.

Gene transfer to chondrocytes

A major advantage of using autologous chondrocytes as cell source for cartilage repair is that their application has already found the way out of the experimental stadium to clinical practice [20]. In recent years, autologous chondrocyte transplantation (ACT) has become a clinically adopted procedure for cartilage defects, especially when marrow stimulation techniques failed to generate good clinical results [145]. In order to further improve the quality of the repair tissue, attempts have been made to enhance this procedure by the use of genetically-modified chondrocytes. Although chondrocytes have been somewhat resistant to transfection with plasmid DNA, certain lipid-based formulations have been found to enhance the efficiency of DNA uptake [106]. Viral based vectors, however, are capable of generating far higher levels of transgene expression with greater persistence. Monolayer expanded chondrocytes are readily transduced by viral vectors, such as Moloney Murine Leukemia Virus (MLV), lentivirus, adenovirus and AAV. Adenoviral-mediated delivery of various transgenes, such as TGF-β1, BMP-2 , IGF-1 or BMP-7, has been shown to stimulate the production a cartilage-specific matrix rich in collagen type II and proteoglycans, and a decreased tendency towards dedifferentiation [75,130,131,157,159]. Transfer of cDNA encoding matrix molecules, such as the collagen type II minigene, led to enhanced extracellular matrix production of human fetal chondrocytes [37]. Transduction with the transcription factor SOX-9 increased collagen type II expression of chondrocytes in three-dimensional culture in vitro [99,167], whereas overexpression of the transcription factor Runx-2 (Cbfa-1) stimulated chondrocyte maturation and induced a hypertrophic phenotype, expressing high levels of collagen types II and X, alkaline phosphatase and osteogenic marker genes [44,84].

Having shown that chondrocyte biology can be positively influenced by genetic modification, research focus has shifted towards their efficient delivery to cartilage lesions. The first approach would be the delivery of genetically modified chondrocytes in suspension. Several studies have shown that genetically modified chondrocytes are capable of expressing transgene products at functional levels following engraftment onto cartilage explants in vitro [42]. In such systems, genetic-modification with IGF-1 [107], FGF-2 [109], or SOX9 [33] led to significant resurfacing and thicker tissue enriched with proteoglycans and collagen type II, compared to transplanted control cells [106]. In addition, adenoviral-mediated IL-1Ra gene transfer to chondrocytes resulted in resistance to IL-1-induced proteoglycan degradation after engraftment [11]. As an alternative to delivery in suspension, efforts have also been made to augment tissue engineering procedures using genetically modified chondrocytes (Figure 1C). For this, the cells are transduced/transfected in monolayer and then seeded into a matrix for subsequent transplantation into chondral or osteochondral defects. In such three-dimensional culture systems, several transgenes have shown promising results in maintaining and promoting the chondrogenic phenotype in vitro, including TGF-β1, BMP-2, -4, -7, IGF-1, SOX9 among others [164,171,177].

Initial studies demonstrated that chondrocytes efficiently expressed reporter genes in chondral and osteochondral defects following genetic modifications with adenoviral, AAV, retroviral or plasmid vectors, and that transgene expression was prolonged for several weeks when the genetically-modified chondrocytes were seeded in three-dimensional matrices [12,82,89,108]. Results of efficacy studies are just beginning to emerge, showing the effects of genetically modified chondrocytes in cartilage lesions in vivo (Table 3). In an ex vivo approach, adenovirally-transduced chondrocytes expressing BMP-7 [75], incorporated in a matrix of autogenous fibrin, were implanted into full thickness articular cartilage defects in horses [75]. Four weeks after surgery, an increased tissue volume and accelerated formation of a proteoglycan and collagen type II rich matrix could be observed in the BMP-7 treated defects compared to control defects treated with irrelevant marker genes. However, after 8 months, the levels of collagen type II and proteoglycan, and the mechanical characteristics of the treated defects compared to the controls were similar. This was attributed in part to the declining number of allografted chondrocytes that persisted in the defects after 8 months [75]. Nevertheless, it is encouraging that genetically modified chondrocytes can be used to augment a cartilage repair process in a large animal model.

Gene transfer to mesenchymal stem cells

The use of autologous chondrocytes for the repair of articular cartilage is limited, as they have to be isolated from a very limited supply of healthy non-weight-bearing articular cartilage, which has to be surgically removed, with the risk of donor site morbidity. Furthermore, chondrocytes dedifferentiate during expansion with a subsequent loss of the chondrocytic phenotype. With regard to cell- and gene-based approaches to cartilage repair, mesenchymal progenitor cells, also referred to as mesenchymal stem cells (MSCs), provide an attractive alternative to chondrocytes. Although no clear phenotype has been described, through the use of the proper culture conditions, expanded MSCs can be stimulated to differentiate along specific pathways such as chondrogenesis, adipogenesis, and osteogenesis [23,25,26,28,86,92,134,135,146,175-177]. MSCs have been isolated from several sources, including bone marrow [147], trabecular bone chips [134], adipose tissue [198], periosteum, perichondrium and others, and have been shown to maintain their multilineage potential with passage in culture [195]. In order to harness MSCs for cartilage tissue engineering, analyses of the appropriate three-dimensional microenvironment to stimulate MSCs toward chondrogenesis in vitro und in vivo have been performed extensively, with factors such as TGF-β1, 2, -3, and BMP-2 emerging among the most popular candidates (see also Table 1). This research has led to the first clinical application of autologous bone marrow stromal cells for the repair of full-thickness articular cartilage defects in humans, which resulted in stable fibrocartilage tissue formation at the defect site [93,187]. However, a successful use of MSCs to aid cartilage repair by means of generating a stable hyaline-rich cartilage repair tissue in vivo, likely requires the efficient delivery of factors to stimulate MSCs toward chondrogenesis, and maintenance of an articular cartilage phenotype without ossification, fibrinogenesis, or inflammation [23,80,177].

In order to meet these requirements, gene therapy approaches hold promise for efficient implementation in cartilage repair procedures. In this context, MSCs are readily transduced by recombinant adenoviral, retroviral, lentiviral, AAV [24,57,195,196] and foamy viral vectors (A. Steinert and A. Rethwilm, unpublished observation). Specific liposomal formulations were used with some efficiency [69,106,107], as well as molecular vibration-based methods [160]. In vitro chondrogenesis has been shown, following plasmid-mediated BMP-2 and BMP-4 [1,163], retrovirus-mediated BMP-2 [27], and adenovirus-mediated BMP-13 gene transfer in the murine mesenchymal progenitor cell line C3H10T1/2. Marrow-derived, primary mesenchymal progenitor cells, genetically modified to express TGF-β1 or BMP-2, were also found to undergo chondrogenesis in aggregate culture, in contrast to IGF-1 modified cultures and reporter gene controls [196]. Interestingly, chondrogenesis in these cultures was also dependent on the level and duration of transgene expression and the viral load, indicating that these factors have to be carefully optimized for a successful in vivo translation of this technology [196].

Some first studies have been performed applying MSC-mediated gene delivery for cartilage repair in vivo. A variety of reporter genes have been successfully delivered to osteochondral defects via periosteal, perichondral or marrow derived MSCs [116,138,140,164,171]. Only a few studies have been conducted using therapeutic genes via MSCs thus far.

A genetically enhanced tissue engineering approach used constructs fabricated of retrovirally-transduced periosteal cells expressing BMP-7, which were seeded into polyglycolic acid scaffolds before transplantation into rabbit osteochondral defects [116,117]. The defects treated with BMP-7 modified progenitors revealed improved regeneration tissue of cartilage and bone, compared to controls after a maximum of 12 weeks post-implantation. In a study using a similar experimental approach, genetically modified periosteal cells transduced to express sonic hedgehog (SHH) were compared to the delivery of the BMP-7 cDNA, which resulted in a better overall repair of the SHH compared with the BMP-7 treated defects after 12 weeks postoperatively, and both were superior to marker gene controls [67]. Using the same animal model, constructs of a collagen type I hydrogel and marrow derived MSCs following liposomal GDF-5 (CDMP-1) gene delivery were shown to enhance cartilage repair compared with marker gene controls [90].

Another approach to study gene-induced chondrogenesis in vivo was devised by Gelse et al. who used gene transfer to MSCs for the repair of partial thickness cartilage lesions in rats [57]. The MSCs were isolated from rib perichondrium and, following adenoviral-modification with Ad.BMP-2 and Ad.IGF-1, delierved via a fibrin glue matrix to partial thickness cartilage lesions of the patellar groove. Both treatment with BMP-2 and with IGF-1 resulted in formation of improved repair tissue rich in collagen type II and proteoglycans, compared with the naïve and Ad.LacZ controls after 8 weeks [57]. However, the majority of BMP-2 treated joints showed signs of ectopic bone formation and osteophytes, which were not present in the knees of the IGF-1 treated defects [57].

In order to simplify elaborate and expensive ex vivo tissue engineering procedures, efforts are underway to facilitate gene delivery approaches to stimulate MSCs at the defect site in vivo toward chondrogenesis. The simplest way of achieving this aim is maybe via direct vector delivery to the cartilage defect site. Toward this end, direct application of recombinant AAV vectors in suspension [32], or of adenoviral vectors incorporated in hydrated collagen-glycosaminoglycan matrices [140] have been found to promote localized transgene expression within the repair tissue formed, following transplantation into cartilage lesions in vivo. However, considerable vector leakage to adjacent synovium was observed [140]. In an attempt to augment this kind of approach with an autologous cellular and space-filling entity, Pascher and colleagues demonstrated that when fresh bone marrow aspirates were mixed with a solution of recombinant adenoviral vectors and allowed to coagulate, MSCs within the coagulum acquired and expressed the transgene for several weeks after implantation into osteochondral defects in rabbits [140]. Studies are underway to investigate how these advances can be harnessed to achieve cartilage repair.

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Challenges for gene therapy to promote cartilage repair

Currently used cartilage repair approaches, both experimental and clinical, are still far from generating a repair tissue that is comparable to the native cartilage tissue quality and stability. To tackle various obstacles toward successful repair, including matrix degradation, differentiation or integration insufficiencies, or loss of the transplanted cells and tissues, efficient delivery of chondrogenic, anti-inflammatory, and anti-oxidative factors seems to be crucial (Table 1). As most of these factors are recombinant proteins, which have short half lives, a repeated local administration is likely to be necessary to achieve the desired result, thus presenting delivery problems. Gene transfer techniques might be adopted that could overcome the limitations of the current treatments for damaged articular cartilage. The current concepts in gene therapy for cartilage repair are reviewed here. Various approaches have been shown to be suited for efficient transfer of exogenous cDNAs to cartilage defectsin vivo, and for achieving sustained expression of the corresponding gene products. Initial efficacy studies indicate that gene-transfer techniques are potent tools that can indeed stimulate a relevant biological response in vivo (Table 3). To date most approaches delivered a strong anabolic transgene aiming to achieve formation of a hyaline-like cartilage repair tissue in vivo, but with limited long-term success thus far. As more data surfaces, a clearer picture of the functional boundaries of current approaches appears. The future challenge therefore is to determine which combination of transgenes will be most suitable for which aspects of repair, and how best to deliver and express them.

Toward this end, the use of more refined vector systems seems to be crucial. Current gene transfer studies to cartilage repair have used vector systems with strong, viral-based promoters enabling very high levels of expression, thus facilitating study of the biological effects that may be achieved with a particular gene and gene delivery method. However it is likely that the stimulation of faithful synthesis of the complex architecture of articular cartilage, followed by its maintenance long-term will require the use of more sophisticated vector systems capable of coordinate control of expression. As many gene products proposed for use can have detrimental side effects if overexpressed in non-target organs such as the heart, lung or kidney, the characterization of the duration of expression in vivo and the biodistribution of vector and/or genetically modified cells following delivery, will be critical. Toward this end, there are several types of cartilage-specific regulatory elements that have been characterized and that might be incorporated into gene delivery systems, such as promoters for the cartilage-derived retinoic acid-sensitive protein (CD-RAP), the procollagen type II α1 (COL2A1), or the aggrecan gene [96,100,127,128,158,173,180,191,197].

Because cartilage injuries are not life-threatening, the safety of gene transfer approaches for repair is of particular importance. To harness the potential of this technology for clinical use is therefore strongly dependent on the use of safe and efficient vectors, transgenes and delivery systems.

This post is more of an extension of the first article “New Proposed Height Increase Method Using Gene Therapy On Engineered Pluripotent Mesenchymal Cells (Breakthrough!)“. It gives the method a more solid theoretical foundation and validity. In the first study, the researchers used recombinant adenoviral vectors carrying the human BMP-2 gene (rh-BMP2) to transduce MSCs to have a prolonged effect of increasing the expression of the protein which the gene is supposed to make.

We saw that bone formation and growth can be regulated or increased from increasing the expression of certain types of growth factors by using an implanted vector.

Update 2/16/2013: At this point I would have to say that idea I had propose in the previous post above has some theoretical backing behind it but is also quite flawed once I go back and read the studies and see what they are actually implying. Those studies showed that the growth factors being made by the mesenchymal stem cells, caused osteogenic effects, not chondrogenic. This just goes to show how science and research and better understand causes out previous understanding to be proven wrong and for us to constantly be changing our level of understanding of the science.

Analysis & Interpretation

Let’s first look at the first study. We are learning a lot from this study. It seems that the BMP-2 which we are so familiar with seem to cause bone cells like osteocytes and osteoblast than say cartilage cells if you inject the growth factor straight into say the epiphysis of long bones in a lab rabbit. The bone formation can be seen in vitro but also in vivo however for the BMP-2 to work in vivo (in the actual lab animal) it has to have really high concentrations, around the mg level of concentration instead of the micrograms which most growth factors are found in. Plus, the effects of the growth factor is really fast and short in time duration. There is an initial injection of the growth factor but that will only get diffused and degenerated after say a few days. To get around the issue of only a small dose and short time frame of dosage, the idea was to inject cells into the rabbit leg bone defects than growth factors.

The cells themselves are the Mesenchymal Stem Cells (MSCs) which can be found from a bone marrow removal and then centrifuged or have some process done to them which would cause the MSCs to be separated, filtered, and then purified. These marrow derived MSCs would be place in a culture. The vectors known as recombinaant adenoviral vector will have the human BMP-2 gene (Adv-BMP2) inside oft  them already. The vectors are added into the culture. The cell membrane of the MSCs which are pluripotent area willing to let the vectors get hooked to a receptor of the outer cell membrane and either let the entire vector inside or just let the gene which the vector was housing to be popped inside into the intercellular matrix of the cell. I would guess then that gene finds it’s way to the surface of the nucleus membrane, get through that, and then somehow cause the genome and chromosomes of the nucleus to start turning on or turning off the specific genes for the specified growth factor. For this case, it is the BMP-2. The cells start expressing the BMP-2 and they start turning into aka differentiating into the bone cell type aka osteoprogenitor cells. The researchers can confirm that the MSCs are turning into bone cells like osteocytes/osteoblasts by using assays and histology to check the level of alkaline phosphatase expression, the amount of Collagen Type I, another compound called osteopontin, osteocalcin, and matrix mineralization.

At the microscopic level with say one cell or a culture of same type pluripotent MSCs this entire changing of cell type is possible using elementary gene therapy techniques.

Now let’s look at the 2nd study. Note that the 1st and 2nd studies/articles are written by the same group of university researchers so the two articles are essentially the same. Right off the bat the researchers state this point, “Bone marrow-derived mesenchymal stem cells are pluripotential cells that have the capacity to differentiate into an osteoprogenitor line”. This was proved from the 1st study. MSCs you find from the bone marrow can indeed differentiate into the bone cell type. They conclude by saying, “We conclude that it is possible to successfully transduce mesenchymal stem cells with the gene for BMP-2 such that these cells will produce the BMP-2 protein in vitro. Further, the transduction results in transformation of these cells into an osteoprogenitor line capable of producing bone in vivo. These data suggest the feasibility of employing gene therapy using recombinant adenoviral vectors as a tool for enhancing spine fusion. Further work to improve the fidelity and longevity of the gene transfer is warranted.” In both articles the researchers put the cells with the vectors for expression BMP-2 into the rabbit’s intervertebral region, between the lumbar vertebrate #5 and #6.

Now let’s look at the 3rd study. Again the researchers are trying to prove that the MSCs you get from bone marrow can turn themselves aka differentiate into the bone type of cells. The setup is however a little different.

• First, there is a culture but there is two types of cultures the MSCs will be in to test for differentiation capacity and extent, a monolayer and then another three-dimensional alginate culture systems
• Second, the MSCs will be tested with getting the adenoviral vectors having both BMP-2 encoding genes and BMP-6 encoding genes.

The results show that the BMP-2 encoded genes seem to work better in getting the pluripotent MSCs to differentiate in both of the culture types for better and/or faster bone formation.

The Actual Method

In the previous post I had talked about the idea of using gene therapy to cause height increase. That was a two step process,

• First is the injection of pluripotent MSCs which would only express chondrogenic genes causing it to produce only chondrogenic growth factors. – This would hopefully result in all the stem cells being injected to turn into chondrocytes.

• Second is the injection of already differentiated chondrocytes with their nucleus getting the adenoviral vector for the up-regulated expression thus the production of growth factors which will cause the chondrocytes , both already inside the epiphysis and then next chondrocyte group injection, to come together and proliferate thus forming a new cartilage inside the epiphysis.

The idea for the previous post was a theory and a proof of concept on how to use the gene therapy techniques we know right now to help us increase height. The truth is that the elements to do the entire process is the basic process of tissue engineering in general. there is always these steps

1. You take a sample from the person’s body which has some stem cells
2. You put the sample through some type of machine to filter the stem cells
3. The stem cells are put in a culture of a certain type to grow them to a certain number.
4. You put the stem cells in some type of matrix or porous scaffold.
5. You add growth factors to the stem cells to make it grow to proliferate
6. You implant that porous scaffold into the human which they came from.
7. You watch to see how well the human body accepts the scaffold filled with the stem cells.

This is tissue engineering. You already have many biomedical researchers doing this type of research for finding ways to regenerate or heal cartilage, but more specifically the articular cartilage in the major joints like the knees and hips.

This step in general is something which I have already done enough research to understand the basic steps of tissue engineering.

Now we are learning how to incorporate genetic engineering/ gene therapy with the tissue engineering to make the stem cells we put in either or both the scaffold or culture to make them do certain things like differentiate, proliferate, hypertrophy, release certain types of growth factors.

For the new and better improve method for height increase is to focus only on the step where the cells themselves have something done to them more than just putting growth factors with them in a culture or scaffold. It is to put a vector with a certain type of protein producing gene in them. This means that the effect for growth factor production or prolfieration will be increased. The dosage will be go along for a longer amount of time meaning that the desired process is increased. Instead of just the first dosage of growth factors effecting the stem cells, the vector will cause the nucleus of the cells themselves to go through the process intrinsically and make it more permanent, at least until the cells go through apoptosis.

From PubMed study 1 In vitro and in vivo induction of bone formation using a recombinant adenoviral vector carrying the human BMP-2 gene.

Calcif Tissue Int. 2001 Feb;68(2):87-94. – Cheng SL, Lou J, Wright NM, Lai CF, Avioli LV, Riew KD.

From PubMed study Induction of bone formation using a recombinant adenoviral vector carrying the human BMP-2 gene in a rabbit spinal fusion model.

Calcif Tissue Int. 1998 Oct;63(4):357-60. – Riew KD, Wright NM, Cheng S, Avioli LV, Lou J.

Source – Department of Orthopaedic Surgery, Washington University, One Barnes Hospital Plaza, Suite 11300 West Pavilion, St. Louis, Missouri 63110, USA.

From PubMed study Gene-mediated osteogenic differentiation of stem cells by bone morphogenetic proteins-2 or -6.

J Orthop Res. 2006 Jun;24(6):1279-91. – Zachos TA, Shields KM, Bertone AL.