Strontium Substituted Nanohydroxyapatite Incorporated 3D Printing Scaffold for Bone Tissue Engineering

The customized implants which are composed of polycaprolactone( PCL) and strontium substituted nanohydroxyapatite( SrHA) were fabricated successfully by using fused deposition modeling( FDM),which is a simple 3 D printing technology for fabricating personalized products. The physical and chemical properties of composite scaffolds were characterized by transmission electron microscopy( TEM), Fourier transform infrared spectroscopy( FTIR), X-Ray diffraction( XRD) and inductively coupled plasma-atomic emission spectroscopy( ICPAES). The results suggested that strontium element was successfully doped into nanohydroxyapatite and all scaffolds showed the homogeneous network structure. Furthermore, the in vitro biocompatibility of the scaffolds was evaluated by cell counting kit-8( CCK-8) assay. The data indicated that the prepared scaffolds exhibited excellent biocompatibility to bone marrow mesenchymal stem cells( BMSCs). Besides,strontium element can be released from PCL-SrHA scaffolds in a sustained manner. Therefore,the 3 D printing PCL-SrHA scaffolds hold great potential for bone tissue engineering.     

Electrospun Chitosan( CS)/Poly( L-lactic-co-ε-caprolactone)( PLCL ) Nanofibers and Their Potential as Small-Diameter Vascular Scaffold

The ideal small-diameter vascular grafts should mimic the nanostructure and mechanical properties of nature blood vessel. In this study, electrospun chitosan( CS)/poly( L-lactic-co-ε-caprolactone)( PLCL) nanofibers were developed for potential small-diameter blood vessel applications. CS is a positively charged polymer which is beneficial for cell attachment and growth,while PLCL provides favorable mechanical support due to its excellent elasticity. Typical nanofibrous structure was observed in both CS/PLCL and pure PLCL scaffolds. The optimal mechanical property could be achieved when the weight ratio of CS/PLCL was 1 ∶ 2.Compared with pure PLCL scaffolds, the CS/PLCL scaffolds showed higher hydrophilicity and markedly promoted the attachment,spreading and proliferation of human umbilical vein endothelial cells( HUVECs). Hence,CS/PLCL scaffolds can be used as potential vascular grafts.