Combination of laser-generated silicon NPs and electrospun-nanofibres for the development of new-generation bioactive wound dressings

Abstract

The fabrication of wound dressings able to promote and accelerate healing is a key challenge to manage a variety of complex wounds including chronic disease or traumatic wounds. In this context, electrospun-nanofibrous scaffolds involving bioactive nanoparticles (NPs) appear as a very promising approach, which was investigated in the present work. We report the fabrication and evaluation of novel bioactive wound dressings associating electrospun ε-polycaprolactone (PCL) imbricated nanofibers (NFs) and laser-synthesized silicon NPs (SiNPs) obtained from green, impurity-free physical routes. A successful protocol of PCL NFs preparation and functionalization with SiNPs was achieved in aqueous acidic solution in the presence of aminopropyltriethoxysilane (APTES). We demonstrated this proof of concept by (1) assessing the effect of the main compositional and process parameters (high voltage, flow rate, collector-injector distance) to yield reproducible NFs, (2) verifying by FTIR the chemical stability of the PCL in the processing conditions, and (3) unveiling the key role of APTES used in the NFs functionalization and their successful association with NPs. On the basis of HR-SEM observations, NFs showed uniform SiNPs distribution throughout the fibers with structural stability in physiological medium. XPS and TEM analyses allowed investigating the SiNPs, and their chemical composition was mainly metallic Si with only top-surface oxidation. Then, physico-chemical, mechanical and bioactivity properties of the NFs were evaluated at three increasing concentrations of SiNPs. All hybrid NFs-APTES-NPs formulations prepared were evaluated from an in vitro biological point of view using two cell types relevant to our final wound healing applications, namely human HaCaT keratinocytes and murine C2C12 myoblasts. In all cases, no cytotoxicity was detected for any of the developed biomaterials, and a proliferative role of the SiNPs was unveiled. The absence of detectable inflammatory potential for all biomaterials tested was also assessed via Griess assays, with even a mitigation effect of the inflammatory response by the NPs. Based on these biological results, an optimized bioactive wound dressing formulation was developed, showing high potential for the management of complex wounds combining biocompatibility, pro-healing capabilities and eco-friendly production. The work opens up exciting perspectives towards the design of efficient bioactive wound dressings based on hybrid electrospun-nanofibers functionalized with laser-synthesized SiNPs.