Preparation Of Agarose Acetate And Its Biocompatibility

Agarose is good biocompatible biopolymer which is widely used in biomedical engineering field. In order to reduce the intermolecular or intramolecule of hydrogen bonding effect, and strong interaction of agarose molecule and water, improve processing properties of agarose gel, and expand applications of agarose as a biomaterial, agarose acetate was synthesized with different substitution degree by acetic anhydride.The structures of agarose acetate were proved with FT-IR,13C-NMR and the chemical titration of ester bond. The most favorable reaction condition was determined through orthogonal test. The reacting condition was that weight ratio of acetic anhydride and agarose was 8, sulfuric acid as catalyst with concentration of 0.125mL/g, and 1.5h of reaction time. When the reacting temperature was 30℃,40℃and 50℃, the substitution degree of agarose acetate was 1.3,2.6 and 3.7 respectively. Thermal gravity analysis result disclosed that agarose acetate absorbed little water, and had different thermal properties from agarose. Results of the contact angle measurements demonstrated that agarose acetate got more hydrophobic than agarose with increase of substitution degree. Under AFM, it was found that the roughness rate of agarose acetate membrane increased with the increase of the substitution degree. The spinning tests proved that agarose acetate had spinnability, and the fiber was not swelled, and their adsorbing rates of water can reach 52.5% minimum. At meantime, agarose acetate could easily form nanoparticle or microparticle in water. These proved that agarose acetate was conveniently processed into porous hydrophobic scaffold or particles loading drug.The result of cell adhesion showed that fibroblasts proliferated on agarose acetate membrane very well, which proved the acetated agaose could improve cell proliferation and the material had the biocompatibility. The results of protein adsorption demonstrated that the materials were prone to adsorb protein.In conclusion, agarose acetate with good processing properties and biocompatibility, is hopeful to be used as tissue engineering scaffold or drug carrer.