Preparation And Biological Evaluation Of Si-doped Hydroxyapatite Composite Scaffold

As the major inorganic component of human bone, hydroxyapatite (HA) is abioactive material which has good biocompatibility and osteoconductivity. However, itslow reaction to bone limits its clinical applications. The modification of HA has attractedmuch attention. Previous reports showed that doping of silicon into HA crystal couldimprove its bioactivity.A series of Si doped hydroxyapatite (Si-HA) was prepared by chemical precipitationmethod. The Si-HA was characterized by Sillcon Molubdenum Blues, XRD, FTIR andTEM. The results showed that part of PO43-in HA was replaced by SiO44-and some ofOH-was lost for charge balance. Particle size and crystallinity of Si-HA reduced with theincrease of Si content.PLGA is often used for tissue engineering scaffolds because of its biodegradabilityand good degradation rate. The Si-HA/PLGA scaffold was prepared by solution casting/ion leaching method and was investigated by SEM, TG and mechanical property. Theresults showed that the prepared scaffold had a hollow structure within which HA/PLGAhad a smooth edge but Si-HA/PLGA had a rough one.SD rat bMSCs were seeded and cultured on the scaffolds for further study ofbiological reaction of Si-HA/PLGA. The CCK-8method were used to measure cellproliferation and HA/PLGA was control. Rat skull critical deficiency mode is a ordinarystandard animal mode and the deficiency mode was created by forming a5mm-diametercircular deficiency in the skull of8-week old male rat. Then H&E staining and Micro-CTwere conducted to observe materials and tissue after4w,8w and12w. The results showedthat doping of Si not only promoted cell culture in vitro, but also benefited reparing theskull deficiency in vivo.