Regenerative Medicines
Regenerative Medicines and Therapies are developed, to replace and restore the damaged organs or tissues with their normal forms, so as to reestablish normal body functioning. Regenerative medicine is an interdisciplinary field that applies engineering and life science principles to promote regeneration, that can potentially restore diseased and injured tissues and whole organs. Currently research and development in the field of regenerative medicines is facing many challenges due to which it does not have a completely established market. But, certainly the field of regenerative medicines will emerge as a promising therapy for disease curing and treatment.
Need for Regenerative Medicines
Organ and/or tissue loss through disease, injury or congenital defect, motivates the development of therapies that can regenerate tissues and decrease the reliance on organ or tisse transplantation. This branch of medicine can potentially provide efficient cure to deadly diseases, it also raises hopes to mitigate congenital disorders and partial paralysis of the body parts. Regenerative Medicines also include the possibility of growing tissues and organs in the laboratory through tissue culture and implanting them when the body cannot heal itself. If regenerated organ’s cells are derived from patient’s own tissue or cells, it would eventually solve the problems of the shortage of organs available for donation, and the problems of graft rejection and resulting strong immune complications. It can potentially heal or replace tissues and organs damaged by age, disease, trauma or congenital defects. Regenerative Medicines can therefore be termed as future of medicines.
Current Research in Regenerative Medicines and Therapies
Basically the research on regenerative medicines and therapies consists of two different strategies namely cell based or synthetic scaffold based, or a combination of both the strategies. The aim behind both the strategies is to obtain organ structure and material composition
Cell Based Strategy
In this process organs are decellularized and recellularized before transplantation. Decellularization removes immunogenic cells and molecules, whilst theorotically retaining structure as well as mechanical properties and material composition of native extracellular matrix. This approach has been executed in animal models of disease with lungs, kidneys, liver, pancreas and heart. Decellularized tissues without recellularization step has also reached the market as medical devices, and have been used to repair cellular defects in human patients. This strategy further needs to be optimized for various parameters to develop new cellular based medical devices for regenerative purposes. Research on the same is actively being carried out.
Scaffold Based Strategy
Synthetic scaffolds are fabricated in a manner to possess at least some aspects of the material properties and structure of the target tissues. It is fabricated from naturally derived materials; hydrogels are largely composed of water and are often used to form scaffolds due to their compositional similarity to tissue. These scaffolds can be engineered to be biodegradable, enabling gradual replacement of the scaffolds by the cells seeded in the graft as well as host cells.
Illustrations of the research work
- Soft fibrin collagen hydrogels have been explored as lymph node mimics, whereas rapidly degrading alginate hydrogels improved regeneration of critical defects in bone.
- In some cases, the polymer’s mechanical property itself are believed to produce therapeutic effects. Like for example, injection of alginate hydrogels to the left ventricle reduced the progression of heart failure in models of dilated cardiomyopathy and is currently undergoing clinical trials (Algisyl).
- Combining materials with different properties can enhance scaffold performance, as was the case of composite polyglycolide and collagen scaffolds that were seeded with cells and served as bladder replacement for human patients.
Regenerative Medicines in Market
A couple of regenerative therapies have received FDA (food and Drug Administration) approval and are commercially available. The cells used in these therapies are either autologous or allogeneic and are typically differentiated cells that still maintain proliferative capacity, for example
- Carticel : It is the first FDA approved biologic product in orthopedic field, it uses autologous chondrocytes for the treatment of focal symptomatic cartilage defect.
- Regranex : Provides a local and sustained presentation of growth factors, thereby promoting wound healing by delivering platelet derived growth factors (PDGF) (Regranex) and bone formation via delivery of bone morphogenic proteins (Infuse). However complications can arise with these strategies, due to poor control over factor release kinetics with currently used materials.
- laViv: Involves the injection of autologous fibroblasts to improve the appearance of nasolabial fold wrinkles.
Measures to be taken for more Successful Implementation of Regenerative Medicines
- Stem cells weather isolated from adult tissue or induced, will often require tight control over their behaviour to increase safety profile and efficacy after transplantation.
- The creation of large engineered replacement tissues will require technologies that enable fully vascularized grafts to be anastomosed with host vessels at the time of transplant allowing for graft survival.
- Creating a proregeneration environment within the patient may dramatically improve outcomes of regenerative medicine strategies. An improved understanding of the immune system’s role in regeneration may aid this goal.
- Administration of cells can induce therapeutic responses by indirect means, such as secretion of growth factors and interaction with the host cells. Therefore Continuous monitoring of post therapy symptoms are crucial.
- 3D human tissue culture models of disease may allow testing of regenerative medicines in human biology, as opposed to current preclinical studies in animal models.
Safety profiles of Regenerative Medicines
Regenerative Medicines are fascinating as it can potentially be an efficient cure to many diseases and body disorders that presently have no cure or are unable to heal by current medicinal procedures. The main issues in tissue engineering and regenerative medicines are tumourigenity, immunogenity and cell migration. A lot of research is being practised only to mitigate the risks involved in employing tissue engineering and regenerative medicines.
Conclusion
Considerable research has enabled the fabrication of sophisticated grafts that exploit properties of scaffolding materials and cell manipulation technologies for controlling cell behaviour and repairing tissue in the host body. The scaffold material is majorly a nanoparticle polymer and is composed of various materials that can be molded into desired shape based on the target organ or tissue. Although regenerative medicines are already in market, increased accuracy of disease models may improve the efficacy of these regenerative medicine strategies and enhance more promising approaches.
Future Scope
It is evident that regenerative medicines will evolve as a completely new era in the field of pharmaceutical and healthcare in the coming future. Further, the right application of Artificial Intelligence in these strategies will enhance the accuracy level of regenerative medicines.
References:
1)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4664309/ (2)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2800311/ (3)https://www.ijoms.com/articles/S0901-5027(17)30244-8/fulltext