In Vivo Study of Porous Calcium Silicate Bioceramic in Extra-osseous Sites

Porous calcium silicate (CS) andβ-tricalcium phosphate (β-TCP) bioceramics were ob- tained by sintering polymeric sponges infiltrated with ceramic slurry.They were implanted in rabbit subcutaneous sites and the biological characteristics were investigated.After 1,2 and 4 weeks implan- tation,specimens were harvested and analyzed by SPECT,Von Gieson staining,Micro-CT,SEM and EDX.There is no obvious toxic reaction in porous CS ceramics,showing the excellent biocompatibility of CS ceramics.In SPECT scanning,the ROI of CS andβ-TCP is (53.95±15.14) and (9.81±3.64), respectively (p0.01),showing higher vascularization for CS.In Micro-CT analysis,the percentage of residual material volume fraction of CS andβ-TCP after 4 weeks implantation is 16.41%±1.96% and 30.72%±0.69% respectively (p0.01).In semi-quantitative analysis of histological observation,the per- centage of residual material in CS is obviously lower than that inβ-TCP.These results show that the biodegradation of CS is higher than that ofβ-TCP.The deposition of the bone-like hydroxyapatite layer after 2 week implantation show good bioactivity of CS in vivo.In conclusion,compared withβ-TCP, porous CS bioeeramies have superiority in vascularization,ingrowth of new tissue and degradation in early stage.Therefore,porous CS bioeeramies may be potential candidates as biocompatible,bioactive and biodegradable scaffolds for hard tissue repair and tissue engineering applications.