A mechanically robust and flexible PEGylated poly(glycerol sebacate)/β-TCP nanoparticle composite membrane for guided bone regeneration

Abstract

The treatment of bone defects in the field of periodontology and oral implantology has been a major clinical problem to date. Guided bone regeneration (GBR), based on ideal barrier membranes to provide space maintenance and selectively promote the regeneration of the damaged area by prevention of invasion by the fibrous tissues, represents the most promising strategy at present. In this study, the mechanically robust and flexible membrane PEGylated poly(glycerol sebacate) (PEGS) coordinated by β-TCP nanoparticles (PEGS/β-TCP) was developed by a simple prepolymer mixing-in situ crosslinking method. By tailoring the content of β-TCP (0, 10, 50, and 90 wt% relative to the prepolymer), the resultant PEGS/β-TCP composite membranes exhibited controllable degradation rate and reinforced mechanical properties. The maximum tensile strength of 9.58 ± 0.02 MPa was presented by the P20T50 group (weight ratio of β-TCP to PEGS20 prepolymer was 50%), about 1.5-fold higher than that of P20T0 without β-TCP. For cellular responses, the PEGS/β-TCP membranes showed desirable cell attachment and viability on rat bone mesenchymal stem cells (rBMSCs). The incorporation of β-TCP definitely enhanced the alkaline phosphatase activity and promoted mineralization, thus facilitating the osteogenic differentiation. The in vivo result obtained for the rat calvarial defect model reaffirmed the favorable bone regenerative ability of the fabricated membranes, especially for P20T50 with the highest bone volume/tissue volume ratio (BV/TV) at both 4 weeks (17.26 ± 1.49%) and 8 weeks (23.24 ± 2.85%) after the surgery. Therefore, the PEGS/β-TCP composite membranes prepared by this prepolymer mixing-in situ crosslinking process will be a prospective biomaterial for the GBR therapy.