Preparation And Mechanism Research Of Polyvinyl Alcohol And Calcium Silicate Bone Scaffolds

Abstract:Biodegradable polymer and bioactive ceramic are the most widely used material of artificial bone scaffold. Especially, polyvinyl alcohol (PVA) is high toughness, biocompatible and easy to process. Calcium silicate (CaSiO3) possesses good mechanical properties, bioactivity and cytocompatibility. In this study, polyvinyl alcohol (PVA) and calcium silicate (CaSiO3) are considered as research object. Selective laser sintering (SLS) is used to fabricate porous scaffold of PVA, CaSiO3and PVA/CaSiO3composite. The properties and sintering mechanism of obtained scaffolds are systemically studied. The main research and innovations in the paper are shown as follows:1) Control software for SLS is developed to fabricate scaffolds with customized shape and interconnected porous structure, which based on the library function provided by6050control card in Delphi. It includes many modules such as laser sintering, movement state monitoring and emergency treatment.2) By the SLS experiment of PVA, a group of optimal parameters is obtained. Scaffolds with different shape, totally interconnected porous structure and high porosity (up to82.35%) are successfully fabricated under the optimal parameters. The sintered scaffolds are able to provide an appropriate living environment for cells. However, there is no obvious deposition on the scaffold after immersed in simulated body fluid (SBF).3) Mechanism studies are carried out on the preparation of calcium silicate scaffolds via SLS. It is found that the mechanical properties of scaffolds are first increased and then decreased as the laser power increase in the range of3-18W. This may because of the variation of compactness and phase composition in the scaffolds. Moreover, the scaffolds have excellent bioactivity, cytocompatibility and osteoconduction.4) In order to combine the advantages of PVA and CaSiO3, PVA/CaSiO3composite scaffolds are fabricated. It is found that the compressive strength of the scaffold with15wt%CaSiO3increases by 43.28%and the compressive modulus increases by61.22%compared to the PVA scaffold. Furthermore, the composite scaffolds exhibit excellent bioactivity and cell biocompatibility.