3D Fiber Deposition And Properties Of Porous Scaffold Prepared By Bioactive Glass Spheres

The bone is easy to be damaged when it suffers from diseases,trauma,decay or genetic problems,thus affecting the health and function of the bone.So saving the bone tissue or inducing it’s regeneration is the research hotspot in the field of bone tissue engineering.BG is an ideal biomaterial for bone tissue regeneration because it is a third-generation biomaterial which has biocompatibility,bone conductivity and inductivity.However,BG prepared by traditional technology still has problems,such as the irregular shape,uncontrolled size and severe agglomeration of BG particles,which could weaken the bioactivity and physicochemical properties of BG when used for bone tissue regeneration.Because of the unique micro/nano-structure,human natural tissues show the absolute advantages of biological function when compared with the traditional synthetic materials.Hence,based on the perspective of bionics,this study used sol-gel method combining template self-assembly technology to synthetize the monodisperse micro-nano bioactive glass spheres with a size of about 350 nm.We used water-soluble polymer polyvinyl alcohol(PVA)and methyl cellulose(MC)as the binder to prepare 3D porous bioactive glass scaffold(BGS).We studied the relationship between the porosity and the pore structure,the physicochemical properties and the apatite-forming activity of BGS and investigated the adhesion and proliferation of mBMSCs cultured on BGS.Main research work and conclusions are as follows:(1)We synthetized monodispersed micro-nano bioactive glass spheres with a size of about 350 nm by sol-gel method combining template self-assembly technology using dodecylamine(DA)as the template agent and hydrolysis catalyst.The BG sphere is consisted of many nano particles,so it is loose and porous.In vitro mineralization research showed that BG spheres have an excellent apatite-forming ability.(2)With PVA as the binder of BG spheres,we prepared 3D porous bioactive glass scaffold by 3D fiber deposition which is one of the rapid prototyping technologies.The scaffold had controllable geometry dimension and adjustable pore structure.We studied the relationship between the porosity and the pore structure of the scaffold.Considering the physical crosslinking effect of PVA,repeated freezing-thawing and heating treatment were used to strengthen the scaffold,so the compressive strength of the scaffold was increased to 23 MPa.The in vitro mineralization experiment showed that BGS has excellent capability of apatite formation.Our research showed that BGS had a good cell adhesion.(3)To improve and simplify the preparation process of the BG slurry for BGS,MC instead of PVA was used as the binder.BGS forming by micro-nanon bioactive glass spheres with a controllable pore structure were prepared using 3D fiber deposition.The BGS went through an enhancing treatment with the use of high concentration of phosphate buffer and the sodium alginate phosphate buffer respectively after drying under room temperature.The structure,morphology,compressive strength and in vitro bioactivity of BGS were investigated by various methods.The results showed that BGS had completely interconnected pore structure,great in vitro apatite-forming ability and excellent comprehensive strength which reached up to 21 MPa.The BGS had good cell adhesion and proliferation effect.In addition,we also studied the influence of enhancing treatment on the degradation property of the BGS.