Composite Electrospun Fibers Containing Optimized B- and Cu-Doped Bioactive Glass Sol-Gel Particles for Potential Soft Tissue Engineering Applications

Electrospinning (ES) is largely used to produce polymeric nano- and microfibers for various applications, including the biomedical fields. ES enables the production of biomimetic fibrous composite scaffolds that resemble the morphology of the extracellular matrix (ECM) of human tissues. However, literature lacks research on composite electrospun fiber tissue engineering (TE). The synergistic effect of biologically active ions with multitarget activity, in comparison to single-target approaches, is also underexplored. In this work, composite fibers based on poly(epsilon-caprolactone) (PCL) incorporating spherical sol-gel B- and Cu-doped bioactive glass (BG) particles, with potential use in soft TE, are fabricated and characterized with scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, contact angle measurements, acellular bioactivity, and mechanical and preliminary cell tests. The composite fibers are obtained by using benign solvents for the ES. The results showed good retention of the BG particles inside the PCL matrix, leading to bioactive behavior. Preliminary in vitro cellular tests with bone marrow stromal cells confirmed the biocompatibility of these fibrous composites. The dual ion release from the bioactive fillers in the PCL matrix is expected to enhance angiogenesis, making the composites relevant for both soft and bone TE.