Preparation, mechanical properties and in vitro degradability of wollastonite/tricalcium phosphate macroporous scaffolds from nanocomposite powders.

A new class of scaffolds with a gain size of 200 nm was prepared from wollastonite/tricalcium phosphate (WT) nanocomposite powders (termed "nano-sintered scaffolds") through a two-step chemical precipitation and porogen burnout techniques. For a comparison, WT scaffolds with a grain size of 2 microm were also fabricated from submicron composite powders (termed "submicron-sintered scaffolds") under the same condition. The resultant scaffolds showed porosities between 50+/-1.0% and 65+/-1.0% with a pore size ranging from 100 microm to 300 microm. The WT nano-sintered scaffolds exhibited compressive strength and elastic modulus values that were about twice that of their submicron-sintered counterparts. The in vitro degradation tests demonstrated that the degradability could be regulated by the grain size of bioceramics. The decreased specific surface area of pores in the nano-sintered scaffolds led to their reduced degradation rate. The mechanical properties of the nano-sintered scaffolds exhibited less strength loss during the degradation process. The WT macroporous nano-sintered scaffolds are a promising and potential candidate for bone reconstruction applications.