Cyclopeptide-ß-cyclodextrin/γ-glycerol methoxytrimethoxysilane film for potential vascular tissue engineering scaffolds.

The mortality rate of cardiovascular diseases is the highest among all mortality rates worldwide. Allotransplantation and autotransplantation are limited by rejection reaction and availability. Tissue engineering provides new avenues for the treatment of cardiovascular diseases. However, the current small-diameter (<6 mm) vascular tissue-engineered scaffolds have many challenges, including thrombosis, stenosis, and infection. Small-diameter vascular scaffolds have structural and compositional requirements such as biocompatibility, porosity, and appropriate phase separation. We used liquid-crystal cyclopeptide（CYC）to modify ß-cyclodextrin and mixed it with γ-glycerol methoxytrimethoxysilane (GPTMS) to prepare CYC-ß-cyclodextrin (ßCD)/GPTMS film by sol-gel. The chemical structure of CYC-ßCD was confirmed by Fourier transform infrared spectroscopy and 1H-nuclear magnetic resonance. The chemical characterization of CYC-ßCD/GPTMS film was performed by differential scanning calorimetry, X-ray diffraction, and small-angle X-ray scattering. The surface morphology and phase separation microstructure of the film were determined by scanning electron microscopy and atomic force microscopy, and the image of polarizing microscopy showed the liquid-crystal structure of the film. Cell culture experiments showed that CYC-ßCD/GPTMS film had good cytocompatibility and induced growth and proliferation of cells. These results indicated the potential applications of CYC-ßCD/GPTMS film in tissue engineering scaffolds.

Synthesis and characterization of L-tyrosine-conjugated quaternary ammonium salt chitosan and their cytocompatibility as a potential tissue engineering scaffold.

A novel amino acid-modified biomacromolecule was designed and synthesized as the quaternary ammonium salt chitosan grafted-tyrosine (CA-g-Tyr) suitable for biomedical applications. L-tyrosine was grafted onto the quaternary ammonium salt chitosan (CA) by N-(3-dimethylaminopropy)-N-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). The chemical structure of CA-g-Tyr was confirmed by Fourier transform infrared (FTIR) spectroscopy and 13C-NMR. The change in the crystalline structure after the graft was characterized by differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). The surface wettability and moisturizing performance of the CA-g-Tyr were also characterized. The CA-g-Tyr film possessed good hydrophilicity, and the mechanical tensile experiments showed that the introduction of tyrosine gave CA mechanical properties more suitable for blood vessel. Cell experiments showed that the endothelial cells can adhere and proliferate better on the surface of a CA-g-Tyr film than CA. The results confirm the favorable properties and biocompatibility of CA-g-Tyr with potential applications as scaffolds for tissue engineering.