Injectable Short Nanofiber Fragments Enable Conformal Fibrous Scaffolds for Tissue Engineering on Complex Surfaces

Polymeric short nanofibers are widely utilized in drug delivery due to their biocompatibility and sustained release properties; however, their application as scaffold-forming biomaterials for tissue engineering remains limited. Here, short nanofiber fragments (SNFs) derived from electrospun poly(D-lactide)/gelatin (PG) nanofiber mats are developed and evaluated for conformal fibrous network formation on complex substrates. SNFs are generated via probe sonication and deposited onto impermeable (carbon tape-mounted aluminum foil) and porous (Ti-6Al-4 V alloy) substrates through drop casting. Scanning electron microscopy reveals that SNFs uniformly coat both substrate types, forming extended, interconnected fibrous networks with effective infiltration into porous structures, unlike direct electrospinning. Surface wettability is significantly enhanced following fragmentation of the nanofiber mat into SNFs, as evidenced by a reduction in water contact angle of 11.5°. In vitro studies using normal human dermal fibroblasts (nHDF) and preosteoblasts (MC3T3-E1) demonstrate that PG3 SNF-coated substrates exhibit excellent cytocompatibility and support time-dependent cell proliferation, comparable to PG3 nanofiber mats. No statistically significant differences in proliferation are observed for either nHDF or MC3T3-E1 at any of the investigated time points. These findings demonstrate that SNFs enable conformal scaffold formation on complex surfaces, offering a promising strategy for advanced tissue engineering applications.