Hybrid nanomaterials of carbon dots of silk sericin and folic acid embedded in bio-derived poly(lactic acid)/silk sericin nanogels and their incorporation with surface-porous electrospun fibers of poly(lactide-co-glycolide) for potential use as scaffolds in tissue engineering and drug delivery system

Hybrid nanomaterials, consisting of carbon dots (CDs), nanogels, and electrospun nanofibers, were developed for tissue engineering and drug delivery. CDs were synthesized using Bombyx mori silk sericin (CD_SS) and SS mixed with folic acid (CD_SSF) and optimized through hydrothermal treatment under various conditions. Extensive analysis was conducted, and CD properties, including morphology, fluorescence, UV–Vis absorption, functional groups, size, zeta potential, and pH-dependent drug release (RhB), were investigated. Both CD_SS and CD_SSF were integrated into bio-derived poly(lactic acid)/silk sericin nanogels, which were further combined with porous electrospun nanofibers of poly(lactide-co-glycolide) (PLGA_(P)). Results revealed that CDs synthesized at 220 °C for 6 h exhibited optimal fluorescence (excitation at 320 and 360 nm), a particle size of 10–30 nm, and a zeta potential ranging from − 15.9 to 19.7 mV. CDs were composed of approximately 55% C, 23% O, and 22% N. The pH-dependent release of RhB was higher in pH 7.4 than in pH 5.0, with a significant increase within 4 h and stabilization after 8 h. Bio-derived nanogels embedded with CDs demonstrated spherical shapes (30–200 nm) and were successfully integrated with PLGA_(P) nanofibers. These nanomaterials were non-cytotoxic to normal human dermal fibroblast (NHDF) cells and promoted complete wound healing in scratch tests within 36 h. In conclusion, these designed electrospun nanofibers, incorporating bio-derived nanogels and CDs, hold promise for tissue engineering, particularly in skin tissue regeneration and controlled drug-release applications.