Zinc oxide nanoparticles (ZnO NPs) are known for their antibacterial, antioxidant, and anti-inflammatory activities. Moreover, ZnO NPs can stimulate cell migration, re-epithelialization, and angiogenesis. All these attributes are highly relevant to wound healing. Local administration of ZnO NPs to the wound can be achieved through electrospun nanofibers. We hypothesized that the use of poly(lactide-co-glycolic acid) (PLGA)/silk fibroin (SF) nanofiber-based delivery of ZnO would maintain the bioavailability of NPs on the wound area and synchronization with the unique structural features of electrospun nanofibers, could stimulate wound closure, re-epithelialization, collagen deposition, cellular migration, and angiogenesis. In this study, we fabricated PLGA/SF (PS) nanofibrous (NF) membranes with and without ZnO NPs and extensively characterized them for various physicochemical and biological attributes. Scanning electron microscopy (SEM) revealed smooth fibers and ZnO concentration-dependent increase in the fiber diameter. Transmission electron microscopy (TEM) also confirmed the encapsulation of ZnO NPs in the polymer matrix. The successful loading of ZnO was further confirmed by X-ray diffraction. Furthermore, mechanical testing revealed a ZnO concentration-dependent increase in the tensile strength. Moreover, biocompatibility was evaluated through in vitro cell culture. A mild anti-oxidant activity was also noted mainly due to the presence of silk fibroin. In vitro antibacterial tests revealed a ZnO concentration-dependent increase in antibacterial activity and PLGA/SF/3% ZnO (PSZ3) remained completely active against E. coli and S. aureus. More importantly, NF membranes were evaluated for their in vivo wound healing potential. The PSZ3 NF membrane not only facilitated the early wound closure but also remarkably enhanced the quality of wound healing confirmed through histopathological analysis. Re-epithelialization, granulation tissue formation, collagen deposition, and angiogenesis are some of the key parameters significantly boosted by ZnO loaded composite NF membranes. Based on extensive characterization and biological evaluation, the PSZ3 NF membrane has turned out to be a potential candidate for wound healing applications.

Background: The shortage of autogenous grafts has often times been a problem in knee ligament reconstruction. There are little data concerning the use of the anterior half of the peroneus longus tendon (AHPLT) as an autograft.

Clinically, rotator cuff tear (RCT) is among the most common shoulder pathologies. Despite significant advances in surgical techniques, the re-tear rate after rotator cuff (RC) repair remains high. Insufficient healing capacity is likely the main factor for reconstruction failure. This study reports on a basic fibroblast growth factor (bFGF)-loaded electrospun poly(lactide-co-glycolide) (PLGA) fibrous membrane for repairing RCT. Implantable biodegradable bFGF–PLGA fibrous membranes were successfully fabricated using emulsion electrospinning technology and then characterized and evaluated with in vitro and in vivo cell proliferation assays and repairs of rat chronic RCTs. Emulsion electrospinning fabricated ultrafine fibers with a core-sheath structure which secured the bioactivity of bFGF in a sustained manner for 3 weeks. Histological observations showed that electrospun fibrous membranes have excellent biocompatibility and biodegradability. At 2, 4, and 8 weeks after in vivo RCT repair surgery, electrospun fibrous membranes significantly increased the area of glycosaminoglycan staining at the tendon–bone interface compared with the control group, and bFGF–PLGA significantly improved collagen organization, as measured by birefringence under polarized light at the healing enthesis compared with the control and PLGA groups. Biomechanical testing showed that the electrospun fibrous membrane groups had a greater ultimate load-to-failure and stiffness than the control group at 4 and 8 weeks. The bFGF–PLGA membranes had the highest ultimate load-to-failure, stiffness, and stress of the healing enthesis, and their superiority compared to PLGA alone was significant. These results demonstrated that electrospun fibrous membranes aid in cell attachment and proliferation, as well as accelerating tendon–bone remodeling, and bFGF-loaded PLGA fibrous membranes have a more pronounced effect on tendon–bone healing. Therefore, augmentation using bFGF–PLGA electrospun fibrous membranes is a promising treatment for RCT.