Photocrosslinkable Col/PCL/Mg composite membrane providing spatiotemporal maintenance and positive osteogenetic effects during guided bone regeneration

Guided bone regeneration membranes have been effectively applied in oral implantology to repair bone defects.However,typical resorbable membranes composed of collagen(Col)have insufficient mechanical properties and high degradation rate,while non-resorbable membranes need secondary surgery.Herein,we designed a photocrosslinkable collagen/polycaprolactone methacryloyl/magnesium(Col/PCLMA/Mg)composite membrane that provided spatiotemporal support effect after photocrosslinking.Magnesium particles were added to the PCLMA solution and Col/PCLMA and Col/PCLMA/Mg membranes were developed;Col membranes and PCL membranes were used as controls.After photocrosslinking,an interpenetrating polymer network was observed by scanning electron microscopy(SEM)in Col/PCL and Col/PCL/Mg membranes.The elastic modulus,swelling behavior,cytotoxicity,cell attachment,and cell proliferation of the membranes were evaluated.Degradation behavior in vivo and in vitro was monitored according to mass change and by SEM.The membranes were implanted into calvarial bone defects of rats for 8 weeks.The Col/PCL and Col/PCL/Mg membranes displayed much higher elastic modulus(p<0.05),and a lower swelling rate(p<0.05),than Col membranes,and there were no differences in cell biocompatibility among groups(p>0.05).The Col/PCL and Col/PCL/Mg membranes had lower degradation rates than the Col membranes,both in vivo and in vitro(p<0.05).The Col/PCL/Mg groups showed enhanced osteogenic capability compared with the Col groups at week 8(p<0.05).The Col/PCL/Mg composite membrane represents a new strategy to display space maintenance and enhance osteogenic potential,which meets clinical needs.