Photocrosslinked PEG-PVP-Pullulan Composites Reinforced With Brushite: A Preliminary Bone-Facing Material for Osteochondral Tissue Engineering
Abstract
Objectives: The development of biomaterials for bone tissue engineering requires a combination of suitable mechanical properties, bioactivity, and cytocompatibility. In this study, photocrosslinked polymer-ceramic composites based on poly(vinylpyrrolidone) (PVP), poly(ethylene glycol) (PEG), and pullulan were developed and reinforced with dicalcium phosphate dihydrate (DCPD, brushite) to obtain bioactive materials with enhanced biological performance. Methods: DCPD was synthesized via a wet precipitation method and incorporated into polymer matrices through UV-induced photopolymerization. The resulting composites were characterized in terms of swelling behavior, hardness, degradation in physiological conditions, surface morphology, and biological response. Cytocompatibility was assessed using direct and indirect cytotoxicity assays, proliferation studies, and scanning electron microscopy (SEM) evaluation of MC3T3-E1 preosteoblast adhesion and morphology. Results: The composition of the polymer matrix significantly affected the physicochemical properties of the materials. Increased PVP content resulted in higher hardness and more developed surface morphology, whereas DCPD incorporation reduced swelling and increased surface roughness. All materials exhibited satisfactory cytocompatibility, with cell viability remaining above the threshold specified by ISO 10993-5. Proliferation studies demonstrated progressive cell growth over time, particularly on DCPD-containing composites. SEM observations confirmed successful cell attachment and favorable cell-material interactions, with the most pronounced response observed for balanced PVP/PEG formulations reinforced with DCPD. Conclusions: The developed PVP/PEG/pullulan-DCPD composites demonstrated promising physicochemical and biological properties and may serve as preliminary bone-facing materials for future osteochondral tissue engineering applications. Further studies are required to investigate their osteogenic potential and long-term biological performance.