Melt electrowriting of bioglass-laden poly(𝝐-caprolactone) scaffolds for bone regeneration

Abstract

This study developed and evaluated polycaprolactone (PCL) scaffolds with 5% (w/w) 58S-bioactive glass (58S-BG) using melt electrowriting. Morphological and chemical characterization of scaffolds was conducted. The biological potential was assessed in vitro with alveolar bone-derived mesenchymal stem cells through cytotoxicity, adhesion, protein production, alkaline phosphatase activity, and mineral nodule formation assays. In vivo, scaffolds implanted in rats were analyzed for biocompatibility, inflammation, and degradation using H&E staining and immunohistochemical markers for angiogenesis and macrophage polarization. Statistical analysis was performed at a 5% significance level. A proper fiber alignment but higher fiber diameter was found for PCL+BG5% compared to PCL scaffolds (p=0.002). EDS spectra confirmed the presence of BG’s chemical components for BG-laden scaffolds, attesting to the particle’s incorporation into the filaments. RAMAN spectroscopy evidenced the bioactive potential of BG powder, and FTIR spectra revealed -OH stretching for PCL+BG5%, evidencing hydrophilic potential. None of the groups were cytotoxic, and BG-laden scaffolds increased cell viability after 7 days (p=0.0006), also showing greater cell adhesion/spreading over time compared to pristine scaffolds. BG presence also increased the mineral matrix formation (p0.0021) over 21 days and maintained ALP activity after 14 days (p=0.705) compared to PCL. In vivo, PCL scaffolds maintained fiber alignment and preserved their volume throughout the evaluation, exhibiting minimal structural disturbance. In contrast, PCL+BG 5% scaffolds showed reduced material retention at 28 days. Despite this, the PCL+BG 5% formulation remained biocompatible and significantly promoted angiogenesis compared to pure PCL scaffolds. PCL scaffolds incorporated with BG particles and produced by MEW showed appropriate properties, including cell viability, adhesion, mineralized nodules deposition, biocompatibility, and angiogenesis, indicating a promising alternative for enhancing bone tissue regeneration.