Janus Nanocomposite for Enhanced Bone Tissue Engineering: Polyurethane Nanofibers with Zoledronic Acid–Silk Fibroin and Silver‐Infused Chitosan Hydrogel

This work presents a hybrid material composed of a physically cross‐linked poly(vinyl alcohol)/chitosan hydrogel with a pore size of 35 ± 10 nm loaded with silver (Ag) nanoparticles (NPs) with a diameter of 83.4 nm. This hydrogel is physically integrated with polyurethane (PU) nanofibers with an average diameter of 0.93 ± 0.5 μm that is preloaded with silk fibroin (SF)‐encapsulated zoledronic acid (ZA) NPs (99.11 nm). However, the hybrid composites are hydrophilic, showing contact angles of <90 o due to incorporating hydrogel and NPs. Ultraviolet‐visible spectrophotometry demonstrates a burst release of ZA from SF NPs within the first 6 h, followed by sustained release up to 48 h, after which the release rate declined. The degradation of hybrid composites in phosphate‐buffered saline (PBS), protease type XIV, and human plasmin shows an increased degradation in the enzyme solutions of protease type XIV (42.6 ± 1.4%) and plasmin (52.6 ± 1.1%) than PBS (27.5 ± 1.9%) after 40 days. Biocompatibility is assessed using 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide and staining, revealing viability of >300% and a higher cell density than the pure PU scaffold. These results suggest that the composite scaffolds offer a highly effective release of loaded NPs are suitable for healthcare products and devices for tissue engineering applications, especially deep wound defects involving bone injuries.