Preparation And Properties Of A Western Blotted Calcium Alginate Composite Hydrogel Film

The polyacrylamide/calcium alginate（PAM/CaAlg）dual network hydrogels have high elasticity and high toughness.However,its mechanical properties will decrease with the increase of time in the physiological environment,and it is easy to swelling.The PAM/CaAlg hydrogel does not have the function of identifying bioactive molecules.In order to promote its application in biomaterials,the first thing is to enhance the stability of the hydrogel by introducing inorganic salts to improve its stability in the victory environment.In the same way the protein molecularly imprinted hydrogels were prepared.According to the bionics principle,bovine serum albumin（BSA）molecular imprinted PAM/CaAlg/PO₄ MIP hydrogel membrane was synthesized through ultraviolet irradiation covalent crosslinking and Ca2+ crosslinking,using sodium alginate（NaAlg）and acrylamide（AM）as the monomer,adding calcium phosphate for calcification,and taking BSA as template molecule.The hydrogel membrane was characterized by SEM,FTIR and TG.The mechanical and swelling behaviors of the membrane were also evaluated.The experiment showed that all the anti-swelling ability and the mechanical behavior of membrane was obviously improved after adding phosphate.The adsorption and release properties of the molecular imprinted membrane were studied by the adsorption and sustained-release test of BSA.The results showed that the surface of PAM/CaAlg/PO₄ MIP membrane had a small pore structure,which was beneficial to the adsorption and diffusion of proteins.The adsorption of BSA by MIP hydrogel membrane was better than that of non-imprinted membrane.The adhesion proliferative capacity of the cells in MIP hydrogel membrane was significantly higher than that of the non-imprinted membrane.The sodium silicate was added in acrylamide and sodium alginate.After polymerization of acrylamide by UV irradiation and calcium ion crosslinking,calcium silicate（CaSiO₃）nanoparticle was introduced in PAM/CaAlg hydrogel.Then the composite hydrogel was soaked in glucose acid-delta-lactone（GDL）aqueous solution.The GDL hydrolytic releases H⁺ and the H⁺ reacts with CaSiO₃ to generate the calcium silicate containing mesoporous silica gel（CaSiO₃@SiO₂）on the surface.In this way PAM/CaAlg/CaSiO₃@SiO₂ composite hydrogel membrane was prepared.The composite hydrogel membrane was characterized by SEM,FTIR,TG-DTG and other methods.The swelling properties and mechanical properties of the hydrogel film in saline were discussed.The CaSiO₃@SiO₂ can produce hydrogen bond interaction with alginate and acrylamide and significantly improve the mechanical properties and stability of PAM/CaAlg hydrogel.The compound hydrogel film can retain 70%of mechanical properties after 24 days of immersion in saline.The adsorption of BSA molecular imprinted PAM/CaAlg/CaSiO₃@SiO₂ composite hydrogel membrane was superior to that of non-imprinted film,and the results of cell culture showed that the surface of the BSA imprinted film adhered to more cells than the non-imprinted surface.The hydrogel membrane preparation process is simple,low cost and excellent performance.Preliminary animal experiments show that the composite hydrogel implant 2 months after cartilage defect parts and the integration of cartilage tissue,appearance no inflammation.The material could be got good application in cartilage repair.