Preparation And Biomedical Application Of Protein-Based Composite Nanoparticles

Composite nanoparticles are nanoparticles composed of two or more materials at either molecule or nanoscale.The physical and chemical properties of the constituent materials can be well-tuned and complemented,taking the advantages of the constituent materials to form new nano-materials with multiple functions.In recent years,with the improvement of living standards,people are increasingly concerned about the composition of materials.According to people's needs,the new material should be green,environmentally friendly and no harm to the human body.But now many nanomaterials have their own shortcomings,it is difficult to fully meet the ideal standard.The emergence of composite nanoparticles is helpful in solving this problem.In our studies,proteins were used as building blocks,whichimproves the biocompatibility and biodegradability of these materials.The mechanism of their formation and biomedical applications are investigated.In this paper,two kinds of composite nanoparticles,namely BSA-BPB composite nanoparticles and CTRA-MSNs composite nanoparticles were synthesized and characterized.BSA-BPB composite nanoparticles are a new type of water-soluble protein nanocubes designed and synthesized by us.Briefly,heating of BSA formed a cube-like protein scaffold.During the heating process,BPB is doped into the scaffold via the binding of BSA and BPB.Since BPB turned out be a molecule containing aggregation induced luminescence(AIE)properties,BSA-BPB nanocubes(BBNCs)in a way resembled AIE-dots.The BBNCs synthesis method is simple,rapid,and cost-effective.Moreover,the protein scaffold provides a very good biocompatible structure.In biological experiments,it can enter the yeast and animal cells through cell endocytosis.Interestingly,the fluorescence signal of BBNCs can penetrate the mouse tissue,suggesting that they are suitable for various biological imaging.CRTA-MSNs composite nanoparticles,is composed of mesoporous silica nanoparticles(MSNs)and ?-chymotrypsin A protein(CTRA).The supramolecular interactions between MSNs,CTRA and its inhibitor PMSF allowed the designing of a supramolecular switch for drug release.CTRA undergoes a change in protein conformation when interacting PMSF,leading to the disassembly of the CTRA-MSNs composite nanoparticles.So CTRA-MSNs composite nanoparticles became a elegant drug loading and release system.This host-guest controlled-release system works smoothly in vitro and in cells.This type of biological switch can be extended to other drug carrier systems by using different protein-inhibitors present in nature.