Supramolecular Self-Assemblies With Nanoscale RGD Clusters Promote Cell Growth And Intracellular Drug Delivery

To construct supramolecular self-assembly biomaterials,not only should we consider the molecules' self-assembly characteristics,but also endow with its biofunctionalities.Amino acids and peptides own many advantages to design novel biofunctional materials,such as selectivity,easily devised and synthesized.Besides,biocompatibility,bioactivity and biodegradation are important factors to build supramolecular self-assembly biomaterials.In this thesis,we expect to construct a novel self-assembled biomaterial which not only could assemble to form nanoparticles for drug delivery,but also could afford the formation of hydrogel which can promote cell adhesion,growth and proliferation.In the first part of this study,we synthesized a novel peptide gelator,named Fc FFRGD,and constructed hydrogel successfully under the condition of 1.0 % and pH=7.4.Through TEM and SEM,we observed the morphology transition of self-assembly over time.Besides,we researched the secondary structure changes by FTIR and CD.More importantly,we utilized 2D cell culture technology to test its biocompatibility.The results showed that FcFFRGD hydrogel can promote cell adhesion,growth and proliferation because of RGD biofuntionality.In the second part of the study,we constructed a kind of drug carrier which was assembled from Fc FFRGD under the condition of 0.1 % and pH=7.4.DOX was encapsulated by FcFFRGD nanoparticles,and the vesicles could keep steady over time.TEM,DLS and fluorescence technology indicated that not only could the nanoparticles encapsulate DOX,but also it owns pH responsive characteristic.When the pH environment reached at 6 or below 6,the vesicles could collapse and release DOX.Through cell uptake test,we found that the vesicles could recognized the integrin on cancer cell surface and take DOX into nucleus,inhibiting the tumor cell's growth and proliferation.