Preparation And Performance Evaluation Of Three Kinds Of Temperature Acellular Carriers

BACKGROUND: The core of the bio-artificial liver composed of cell scaffold, scaffold need has good biological compatibility, three-dimensional porous structure, suitable mechanical properties, good cell affinity and cells without damaging the desorption etc. The design and preparation of novel thermo-responsive polymer three-dimensional cell scaffold is one of the hot topics in the research of polymer science.OBJECTIVE: To prepare three different kinds of temperature cell carriers, simulate the function of extracellular and evaluate their performance.METHODS: The copolymer N-isopropylacrylamide temperature cell scaffold, macroporous copolymer N-isopropylacrylamide temperature cell scaffold and macroporous copolymer N-isopropylacrylamide crosslinking aldehyde sodium alginate temperature cell scaffold were prepared. The specific surface area, thermo-responsive performance, porosity, pore size and biocompatibility of these three groups of scaffolds were determined.RESULTS AND CONCLUSION: 1.Synthesis of PNA 3D cell scaffold through thermo-responsive property of P(NIPAm-AAm); Interconnected porous three-dimensional cell scaffold PNAK made by thermo-responsive P(NIPAm-AAm) through sodium alginate as porogen; By Schiff reaction in P(NIPAm-AAm) crosslinking aldehyde sodium alginate(OSA), PNAKO made by interpenetrating network structure of three-dimensional porous scaffolds through sodium alginate as porogen. 2.It was proved that P(NIPAm-AAm) and OSA had a chemical cross-linking reaction,-CHO reaction on-NHNH2 and OSA on PNIPA-AM was generated by C=N bond. 3.The thermo-responsive of cell scaffold of specific surface area(s) are measured and the results show that, PNA is only 135m2/g; PNAK cell scaffold due to have internal sodium alginate as the pore forming agent to form porous structure, the specific surface area is increased greatly, reach to 386m2/g; PNAKO cell scaffold due to not only takes sodium alginate as the pore forming agent and crosslinking aldehyde sodium alginate(OSA) formation of interpenetrating network structure, make the specific surface area reach to 421m2/g.It shows that PNAKO PNAK has more obvious pore structure than the PNA. 4.SEM shows that PNA temperature cell scaffold with irregular pore structure, the thermo-responsive of PNAK off cell scaffold with regular porous structure, hole is dense and uniform distribution, penetration of each connected. Pore forming agent sodium alginate leads to thermo-responsive produced porous structure. PNAKO with interpenetrating network porous structure, hole is dense and uniform distribution, penetration of each connected that the thermo-responsive crosslinking aldehyde sodium alginate, and join the induced pore forming agent sodium alginate resulted in a thermo-responsive gel interpenetrating network porous structure. 5. LCST properties of three kinds of thermo-responsive cell scaffolds showed that three kinds of cell scaffolds had the characteristics of temperature sensitivity, and the temperature of LCST was close. LCST of PNA is about 30?, LCST of PNAK is about 28.5?, LCST of PNAKO is about 29.5?. 6. Three kinds of cell scaffold swelling rate(SR) measurement indicated that three thermo-responsive cell scaffold swelling degree can make temperature control cell scaffold remained shape, not due to inhalation of a multicellular medium over saturated and lose shape or even disintegration, but also enough to meet cellular access to nutrition and metabolism of transmission.7. Pore size and porosity of three cell scaffold shows that PNAK PNAKO are significantly greater than PNA, due to the irregular pore structure of PNA, experimental data shows average values, so as a cell scaffold, PNAK and PNAKO are better than the PNA 8. Biocompatibility of three cell scaffold shows PNAKO has low cyto-toxicity due to crosslinking aldehyde sodium alginate, biocompatible is better than PNA and PNAK, PNAK did not change significantly compare with PNA.It can be known that PNAKO is the best cell scaffold through the experiments. 9. Induction of hepatocyte like cells in PNAKO cultured for 28 days, it shows good cell morphology, growth closely, distributed in the surface and pores of the carrier, indicating a good compatibility of scaffolds and cells. 9.The results showed that the PNAKO scaffolds were contracted and the cells took off automatically when the ambient temperature was decreased. This temperature induced desorption method can avoid the damage caused by enzymatic hydrolysis, which can maintain the original function of cells. The average rate of the PNAKO stent temperature control cells could reach 41.09%.