Green Light‐Based Photobiomodulation with an Implantable and Biodegradable Fiber for Bone Regeneration

Abstract Photobiomodulation (PBM) has recently started to gain popularity in clinical therapeutics. Visible light, in particular, plays a critical role in osteogenesis modulation. However, the limited penetration depth of visible light in biological tissues has constrained the application of this technology in vivo. Herein a green light‐based PBM technique with implantable and biodegradable poly(L‐lactic acid) & poly(L‐actic‐co‐glycolic acid) optical fibers to achieve accelerated bone regeneration is explored. Facilitated with experimental characterizations as well as numerical simulations, optical and thermal behaviors of fibers operated in the biological environment are understood. The optical regulation of bone regeneration is systematically studied both in vitro and in vivo. Under green light irradiation, biochemical activities of bone marrow‐derived mesenchymal stem cells and their expression of osteogenic‐related factors are significantly elevated. By introducing green light into defective bone structures via fibers in a rodent model, the process of bone regeneration and repair is accelerated. Furthermore, fibers exhibit ideal biocompatibility with both cultured cells and living tissues and undergo complete degradation in vivo after ≈1 month. Assisted with degradable optical materials and devices, such as photobiomodulation technique provides a promising solution to tissue regeneration in various biomedical applications.