Studies On Preparation Of LCC Based Degradeble Scaffold Material And Compatibility With Human Cells

With the acceleration of people’s pace of life,the pressure of life is also increasing,which in turn leads to more and more people suffering from myocardial infarction,liver cirrhosis and other diseases.Therefore,a large number of people die each year from liver diseases(such as liver cancer,liver cirrhosis)and heart diseases(such as coronary heart disease).Liver cancer and coronary heart disease are very serious threats to human health.The usual treatment used for liver disease and heart disease is liver transplantation and cardiac scaffold.The various scaffold currently used have their own drawbacks,so it is extremely urgent to find a scaffold material that is better in all aspects.Lignin-carbohydrate complexes(LCCs)have good amphipathic properties,biocompatibility,non-toxicity,degradability and other properties,and are very good medical polymer materials.The application of LCC in tissue engineering scaffolds is investigated in this thesis.In this thesis,water-insoluble fractions of poplar LCC-48 and LCC-72 were prepared under different milling time(48h and 72h).above-mentioned LCC were used to prepare dried hydogel type porous carrier in the presence of polyethylene glycol glycidyl ether.FT-IR analysis results showed that the above two LCC samples were composed of lignin and polysaccharides,and showed a typical LCC structure.The galactose contents of LCC-48 and LCC-72 were 3.02%and 5.67%,respectively,indicating that LCC-72 is more easily recognized by human hepatocytes.The molecular weights of LCC-48 and LCC-72 were 9836 and 7153,respectively.The specific surface areas of the LCC-48 and LCC-72 based porous scaffold were 26.311 m~2/g and 21.263m~2/g,and their pore diameters were 29.627 nm and 23.812 nm,respectively.As the milling time increased,the porosity and pore size of the porous material from LCC decreased.The above dried gel type porous carrier was used for culture of human liver cells L-02.A large number of hepatocytes adhered to the porous carrier was observed through an inverted microscope and a scanning electron microscope(SEM).There were more hepatocytes grown on the LCC-72-based carriers than the LCC-48-based carriers and the control group.The results of measurement of albumin secretion,blood urea nitrogen secretion,and glucose consumption of the cells cultured in vitro indicated that LCC-72 was superior to LCC-48 and blank samples.Using LCC-48,LCC-72 and cellulose nanocrystals(NCC)as raw materials,composite spherical porous carriers were prepared by liquid nitrogen freezing.The morphology and components of the spherical carrier were analyzed by infrared spectroscopy and SEM.The above spherical carriers were used for human hepatocyte L-02 culture.The cultured cells were observed by an inverted microscope.Cell count,SEM observation,and the metabolic activity of the cells were analyzed.The results showed that the composite spherical carriers had a typical structure of lignin and polysaccharide complexes.The specific surface areas of LCC-72/NCC complex spherical carrier and LCC-48 complex spherical carrier were 24.262 m~2/g and 28.938m~2/g,respectively.The pore size were 28.617 nm and 33.565 nm,respectively.Observation by inverted microscope and SEM showed that a large number of hepatocytes adhere to the porous carrier.There were more hepatocytes grown on LCC-72/NCC-based complex spherical carriers than LCC-48/NCC-based complex spherical carriers and the control.The albumin secretion,blood urea nitrogen secretion,and glucose consumption of cultured cells in vitro showed that the LCC-72/NCC spherical composite carriers were superior to the LCC-48/NCC complex spherical carrier and blank group.The biocompatibility of LCC/NCC spherical carriers increases with the increase of LCC content.When the LCC content exceeds 50%,the biocompatibility of LCC/NCC complex carriers no longer changes with the change of LCC content.With the use of LCC-48,LCC-72 and cellulose nano-fibrils(CNF)as raw materials,complex tubular carriers were prepared by cast film formation method and curl forming method.The morphology was analyzed.The carriers were applied to culture the human coronary artery endothelial cells.During the culture in vitro,the cells were observed and counted by inverted microscope and SEM.The activities of these cells were examined.The results showed that the specific surface areas of LCC-72/CNF complex tubular carrier and LCC-48/CNF complex tubular carrier were 3.497 m~2/g and 3.956m~2/g,respectively.And their pore sizes were 8.302 nm and 9.001 nm,respectively.Inverted microscope and SEM observations showed that a large number of coronary endothelial cells adhered to the porous carrier.There were more coronary endothelial cells grown on the LCC-72/CNF complex tubular carrier than on the LCC-48/CNF-based carriers and the control group.The albumin secretion,blood urea nitrogen excretion,and glucose consumption measurement showed that the biological activities of the LCC-72/CNF complex tubular carrier were better than that of the LCC-48/CNF complex tubular carrier and the control sample.The biocompatibility of LCC/CNF spherical carriers increased with the increase of LCC content.When the LCC content was more than 60%,the biocompatibility of LCC/CNF no longer changed with the change of LCC content.