Preparation And Properties Of A Novel 3D-printed PLGA/MSNs Porous Composite Scaffold

Background: In clinical settings,cartilage defects have a high incidence;however,there are few effective therapies for such conditions.In recent years,the emerging tissue engineering has provided a new direction for restoration of cartilage defects.As one of the three key elements in tissue engineering,scaffolds are of great importance in cartilage regeneration by cartilage tissue engineering strategy.As scaffold material,poly(lactic-glycolic acid)(PLGA)is characterized by good biocompatibility and mechanical properties,high plasticity,and controlled degradation,but poor hydrophilicity.Mesoporous silica nanoparticles(MSNs)are reputed for their low toxicity,stability,good biocompatibility and hydrophilicity that when incorporated in PLGA,they are supposed to improve the hydrophilicity and biocompatibility of the composite.Low-temperature deposition manufacturing(LDM)is a three dimensional printing technology with virtues of easy manufacturing,less pollution,and bioactivities maintainance of materials.Scaffolds with three dimensional and porous structures can be obtained by LDM.Purpose: To prepare PLGA/MSNs composite scaffolds,followed by characterization of their physical and chemical properties,and detection of their biocompatibility through cell seeding on scaffolds in vitro to obtain a scaffold with more outstanding properties.Methods: 1.PLGA and PLGA/MSNs composite scaffolds were fabricated by LDM and their morphological structures,pore sizes,porosity,hydrophilicity,mechanics and composition were examined.2.The human bone marrow mesenchymal stem cells(hMSCs)were cultured and passaged,and then co-cultured with the scaffolds.Cell counting kit(CCK)-8 assay was conducted to detect cell proliferation on the scaffolds.Live & dead cells staining assay and scanning electron microscope were performed to observe adhesion,distribution,and morphology of the cells on the scaffolds.Results: The PLGA and PLGA/MSNs scaffolds prepared by LDM have ideal threedimensional porous structures.The macro-pore size and micro-pore size were in round shape and interconnected.The composite scaffold had smaller macro-and micro-pores,and enhanced mechanics,hydrophilicity,and biocompatibility.There was no significant difference in porosity between both types of scaffold.Fourier Transform Infrared Spectroscopy examination confirmed incorporation of MSNs into PLGA.The result of CCK-8 assay and live & dead cells staining assay proved that cells had improved proliferation on the composite scaffold.The results of scanning electron microscope observation showed that the cells adhesion,distribution and stretch morphology were better on the composite scaffold.Conclusion: The 3D-printed PLGA/MSNs scaffolds had desirable three dimensional and porous structures with improved biological properties and may be an ideal scaffold for cartilage tissue engineering.