Ion-Doped Bioglass-Integrated Polycaprolactone Fibers for Advanced Tissue Engineering

Objectives: This study aimed to synthesize and characterize two bioactive glasses (45S5 and 58S) using three dehydration methods (calcination, lyophilization, and lyophilization+calcination) and incorporated them into polycaprolactone (PCL) fibers obtained through the electrospinning process.
Methods: The bioactive glasses were synthesized via sol-gel method using silicic acid as precursor and divided into subgroups based on the dehydration method (C – calcined; L – lyophilized; LC – lyophilized and calcined). PCL solution was prepared (2.4 g in 12 mL acetone - control group), and the glasses were added (1:1 mass ratio), resulting in seven experimental groups. Fibers were electrospun under fixed parameters (10 kV, 12 cm, 2 mL/h, 300 rpm). Characterization was performed by scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD), FTIR, and apatite mineralization assay in simulated body fluid (SBF). Fibers were characterized by SEM, average diameter analysis, energy-dispersive X-ray spectroscopy, XRD, FTIR, thermogravimetry, and SBF assay. The glass 45S5 LC was selected for its pH stability, rapid conversion to hydroxyapatite (HAp), optimized structure, and porosity achieved through calcination and lyophilization processes. This group was doped with magnesium and lithium ions, and characterization and incorporation into PCL fibers were repeated.
Results: The sol-gel method, combined with dehydration processes, was effective in producing silicate-based chlorinated bioactive glasses with high bioactive potential. Calcination resulted in Q2 structures, while lyophilization alone produced combinations of Q1, Q2, and Q3, providing distinct structural characteristics. The 58S glass was identified as amorphous, while the 45S5 glass exhibited crystallinity with sodium chloride. Both glasses contained functional groups essential for bioactivity, such as Si-O-Si and silanol. The assays confirmed HAp formation and pH control via Ca-P-Cl phase in 45S5-L+C glass.
Conclusions: Successful synthesis of ion-doped 45S5 and 58S glasses using different dehydration methods was demonstrated, with 45S5 LC showing optimal pH stability, HAp formation, and porosity. Incorporating these glasses into electrospun PCL fibers highlighted their potential for tissue engineering.