Biodegradable polymer nanocomposites for ligament/tendon tissue engineering
Ligaments and tendons are fibrous tissues with poor vascularity and limited regeneration capacity. Currently, a ligament/tendon injury often require a surgical procedure using auto- or allografts that present some limitations. These inadequacies combined with the significant economic and health impact have prompted the development of tissue engineering approaches. Several natural and synthetic biodegradable polymers as well as composites, blends and hybrids based on such materials have been used to produce tendon and ligament scaffolds. Given the complex structure of native tissues, the production of fiber-based scaffolds has been the preferred option for tendon/ligament tissue engineering. Electrospinning and several textile methods such as twisting, braiding and knitting have been used to produce these scaffolds.
Tendons and ligaments have poor regeneration capacity with low cell density and low nutrient and oxygen requirements. Injuries in these tissues such as in anterior cruciate ligament (ACL) are frequent in athletes and in elder and active working people, which cause joint instability accompanied by pain, disability, progressing of degenerative diseases and often, surgical interventions.
Current surgical reparative techniques rely on tissue replacement with auto- or allografts Despite excellent outcomes in terms of short-term results, serious complications are related to their usage and 5-year studies show that patients have instability and pain. The main problems about the use of autografts include the need of additional surgery with potential donor harvest site infection and pain. On the other hand, concerns about using allografts are limited graft availability or even the risk of disease transmission, bacterial infection and the possibility of immunogenic response elicited in the host. The need to address the shortcomings of existing strategies has prompted the investigation of synthetic and non-degradable substitutes1.
1. Silva, M., Ferreira, F. N., Alves, N. M., & Paiva, M. C. (2020). Biodegradable polymer nanocomposites for ligament/tendon tissue engineering. Journal of nanobiotechnology, 18(1), 23. https://doi.org/10.1186/s12951-019-0556-1