Some tissues heal better than others after surgery. Connective tissue like tendons and ligaments don’t heal well, but they are injured quite frequently.
Cytokines and growth factors like PDGF, VEGF, TGF-beta, and bFGF are able to improve healing outcomes. The problem is releasing them close to the site of injury and over a long period of time. You don’t want them in circulation because they might cause cancer.
Coating surgical sutures is an obvious solution. However, the surface area is limited (you can’t actually load many molecules onto them), the molecules rub off during implantation, and the growth factors are released quickly after use (e.g., 100 hours). A group at Georgia Tech led by Younan Xia and first author Jianhua Li developed medical sutures that are porous. This paper was published in 2016, so I am looking forward to results in vivo.
Li, J. et al. (2016) Surgical Sutures with Porous Sheaths for the Sustained Release of Growth Factors. Advanced Materials.