One-Step Electrospinning-Driven Optical Engineering of ZnO Nanoparticles for Fabricating Biomedical Textiles

Nanoparticle-embedded biomedical mats often demonstrate heterogeneous and nonrobust performance owing to nonuniformity in their crystal structures and Ostwald ripening. To overcome this issue of nanoparticle engineering, this study leverages high-voltage electrospinning as a one-step solution to tailor the crystalline structure of zinc oxide nanoparticles (ZnO NPs) embedded in a polycaprolactone (PCL) matrix. The electrospinning-assisted ZnO NP-embedded micro/nanofibrous matrix has been termed ENZO. The high-voltage-induced Coulombic forces introduced additional surface defects, leading to (i) an 82% increase in fluorescence intensity, (ii) a 29% reduction in size, and (iii) a 17% increase in d-spacing in the ZnO NPs of ENZO22 mats (mats fabricated at the highest voltage, 22 kV) as compared to their pristine counterparts, thus confirming successful engineering of the nanoparticles. The micro/nanofibrous matrix of ENZO22 demonstrated homogeneous distribution of the ZnO nanoparticles, which also contributed to its superior fluorescence intensity, mechanical performance, and surface characteristics. In contrast to conventional methods of nanoparticle engineering, such as thermal or chemical-based methods, this single-step electrospinning process avoids toxic dopants, improving biocompatibility and scalability. Cytocompatibility tests of the mats, conducted with primary human dermal fibroblast (HDF) cells, revealed excellent cell adhesion and proliferation (127% cell viability as per MTT assay, and <120% LDH activity). Finally, more than 99% reduction in the colony-forming units of Gram-positive Bacillus subtilis and Gram-negative Escherichia coli bacteria in the presence of ENZO22 mats confirmed their antibacterial nature. This has been validated by metal-ion-induced reactive oxygen species generation. High-voltage-induced nanoparticle engineering in ENZO mats endowed them with superior mechanical and optical properties, accompanied by high cytocompatibility and antibacterial activity, making them an ideal candidate for their prospective applications in tissue engineering and for the development of smart biomedical scaffolds.