Bioactive phosphate-containing electrospun PVA nanofibers incorporating calcium phosphate and magnesium phosphate

Bone-mimetic scaffolds are pivotal components in bone tissue engineering, particularly those exhibiting intrinsic bioactive characteristics. This study presents nanocomposite scaffolds with enhanced biomineralization potential based on electrospun poly(vinyl alcohol) (PVA) nanofibrous matrices incorporating magnesium phosphate (MgP) and monocalcium phosphate (MCP). FTIR analysis revealed the formation of non-covalent interactions, such as hydrogen bonds and electrostatic attractions, between the nanoparticles and the PVA chains, confirming their successful incorporation. The incorporation of 0.5 w/v% MCP and MgP contributed to a reduction in the average fiber diameter from 541 nm for the PVA/surfactant formulation to 284 and 257 nm, respectively, while producing narrower fiber diameter distributions. Increasing MCP or MgP concentrations from 0.5 to 1.5 w/v% led to a non-linear variation in fiber diameter, with the average fiber diameter initially increasing and then decreasing. Strong intermolecular interactions between PVA and phosphate phase enhanced thermal stability of the composite scaffolds, as evidenced by the increase in the temperature of the maximum degradation rate from 280 °C for neat PVA to 290 °C and 300 °C for PVA/MCP and PVA/MgP, respectively. After 21 days of immersion in simulated body fluid (SBF) at 37 °C, SEM, EDX, and XRD analyses confirmed the substantial surface mineralization and phase transformation in both composite systems. The PVA/MCP scaffolds predominantly developed hydroxy apatite-like calcium phosphate, whereas PVA/MgP scaffolds exhibited newberyite and bobierrite phases. The results reveal that incorporation of MCP and MgP modulates the physicochemical properties and biomineralization behavior of electrospun PVA nanofibers.