Cytocompatibility of electrospun polyvinylidene fluoride piezoelectric bionic periosteum / 中国组织工程研究

BACKGROUND:Polyvinylidene fluoride(PVDF)with piezoelectric properties,good biocompatibility and nontoxicity make it a suitable candidate for periosteal repair. OBJECTIVE:To evaluate the cytotoxicity of PVDF bionic periosteum by electrospinning with zinc and magnesium ions in vitro. METHODS:Pure PVDF,zinc-doped PVDF,magnesium-doped PVDF and Zinc-magnesium ion PVDF piezoelectric bionic periosteum were prepared by electrospinning technology,respectively.They were named PVDF,PVDF-Zn,PVDF-Mg and PVDF-Zn-Mg,in which the mass fraction of zinc and magnesium ions were all 1%.Osteoblasts and vascular endothelial cells were co-cultured with four groups of bionic periosteum.Cell compatibility of bionic periosteum was determined by alkaline phosphatase staining,CD31 immunofluorescence staining,and scanning electron microscopy. RESULTS AND CONCLUSION:(1)Osteoblasts:Alkaline phosphatase staining after 7 days of culture showed that the PVDF-Zn group secreted more alkaline phosphatase than the other three groups.Under a scanning electron microscopy,after 1 day of culture,the cells had a certain spread on the surface of PVDF-Mg and PVDF-Zn-Mg bionic periosteum,and the pseudopod extended to all sides.On day 3,the cell edge of each group extended pseudopods to the material.By days 5 and 7,the cells were fully spread,well grown and firmly covered the surface of the fibers,and the cellular pseudopods extended around and into the interstitial space of the fibers.CCK-8 assay showed that the cell proliferation on the bionic periosteum of each group showed an increasing trend over time and the relative proliferation rate of cells at 1,3,5,and 7 days was≥75%,and the cytotoxicity was≤grade 1.(2)Vascular endothelial cells:CD31 immunofluorescence staining for 3 days showed that the cells adhered and spread well on the bionic periosteum of each group and connected with each other,and the number of cells in the PVDF-Zn-Mg group was more than that in the other three groups.Under scanning electron microscope,the cells began to adhere to the surface of each group of fibers after 1 and 3 days of culture.On day 5,the cells were well spread on the surface of the fibers and extended obvious pseudopods.On day 7,the cells on the PVDF-Mg and PVDF-Zn-Mg bionic periosteum grew in multiple layers and extended the pseudopod into the fibrous void.CCK-8 assay showed that the cell proliferation on the bionic periosteum of each group showed a downward trend over time,and the relative proliferation rate of cells at 1,3,5 and 7 days was≥125%,and the cytotoxicity was grade 0.(3)The results showed that Zn-Mg electrospun PVDF piezoelectric bionic periosteum had good cytocompatibility.

Preparation, physicochemical characterization and cytocompatibility study of self-assembled silk fibroin nanoparticles / 药学学报

This study aimed to prepare silk fibroin nanoparticles (SF-NPs) and assess the physicochemical properties and biocompatibility of the formulation. An optimized and simplified solvent displacement method was employed to obtain SF-NPs. Single-factor prescription screening, such as silk fibroin (SF) solution concentration, the ratio of SF solution to organic solvent, ultrasonication power and time, and different types of organic phases, was used to optimize the formulation. The characterization of the optimal formulation included particle size, polydispersity index (PDI), zeta potential, morphology, and stability. The in vitro cell compatibility of the nanoparticles was evaluated using CCK-8 and Calcein-AM/PI cell viability staining. The results showed that when SF concentration was 20 mg·mL-1, volume ratio of aqueous phase to acetone was 1∶6, ultrasonic power was 80 W and ultrasonic time was 3 min, the best SF-NPs was obtained. The nanoparticles prepared in this study exhibit a near-spherical shape, with a uniform size distribution, having an average size of 144.8 nm, a PDI of 0.174, and a zeta potential of -27.35 mV. Results from in vitro cell experiments demonstrate excellent cell compatibility of SF-NPs, showing the ability to promote cell proliferation. The SF-NPs which were successfully prepared in this study exhibit uniform particle size and excellent biocompatibility.

Preparation of bilayer spider silk protein vascular scaffold and its biomechanical properties and cell compatibility / 医用生物力学

Objective To prepare a bilayer spider silk protein vascular scaffold using electrospinning, observe microstructure of the vascular scaffold and study its biomechanical properties and cell compatibility. Methods Spinning solution was electrospun to prepare (pNSR16/PCL/CS)/(pNSR16/PCL/Gt) bilayer spider silk protein vascular scaffold using rotating receiving rod as the collection device. The effects of mass fraction and wall thickness on the porosity, bursting strength, tensile properties, suture retention strength and water permeability of the vascular scaffold were investigated, and cytotoxicity and cell adhesion property of the vascular scaffold were tested. Results The vascular scaffold presented three-dimensional porous microstructure with randomly distributed fibers. The bursting strength, tensile strength and suture retention strength were directly proportional to mass fraction and wall thickness, but the porosity, water permeability and elongation at break were inversely proportional to mass fraction and wall thickness. The bursting strength range of vascular scaffold was 43~183 kPa, which was higher than the physiological blood pressure; the suture strength was above 0.19 N, which was consistent with the transplantation requirement in vivo; the tensile strength was higher than that of human radial artery, which met the transplantation requirement in vivo; the range of water permeability was 0.3~0.6 mL•min-1•cm-2. The vascular scaffold had no cytotoxicity and facilitated the adhesion and proliferation of endothelial cells. Conclusions It is feasible to prepare the bilayer spider silk protein vascular scaffold through electrospinning. The superior biomechanical properties and biocompatibility properties show that the bilayer spider silk protein vascular can be used for construction of the tissue engineered blood vessels in vitro, with prospect for further vascular graft study, which lays a foundation for its clinical application.

Study on the cell compatibility of polystyrene plate chemically modified by RGD peptides / 国际生物医学工程杂志

Objective To investigate the cell compatibility of polystyrene(PS) plate chemically modified with RGD peptides.Methods PS surfaces were carboxylated by permanganate oxidation in diluted sulfuric acid,and carboxyls were activated with water-soluble carbodiimide to graft with gelatin,collagen and RGD peptides.IR,X-ray photo-electronic spectroscopy (XPS) and dynamic contact angle were used to characterize the surface modification of PS surface.Results XPS results confirmed the existence of nitrogen element from protein molecules and the covalently binding of proteins to PS surfaces.Dynamic contact angle measurement indicated hydrophilicity of PS surfaces was improved obviously after grafting modification.The cell culture results showed that the cell adhesion and proliferation was better on modified surfaces than the initial.Conclusion The cell compatibility of PS surface was great improved after modification with RGD peptides,which would provide a potential strategy to improve the culture of purified endothelial progenitor cells isolated by immunomagnetic beads.