Design Of Protein Nanoparticles With Protein Adsorption Resistance And Their Photodynamic And Photothermal Effects

In the 21 st century,nanotechnology has developed rapidly,especially in the field of targeted therapy of nano-drugs,which has a very broad prospect.By controlling particle size and surface electrical properties,the drug delivery and release capacity can be improved,and targeted substances such as folic acid,antibodies and aptamers can be modified on its surface.It can make it have a good ability of specific recognition of tumor cells,so as to accurately locate and improve the efficiency of drug treatment.However,when nano-drugs enter the internal biological environment,all kinds of biomacromolecules will be absorbed on the surface of nano-particles,which will bring negative effects on the drug effect,such as losing the ability of targeted identification of nano-particles,causing complement excitation,and easily being discharged as foreign antigens.Looking for fouling resistance excellent materials as drug carrier has become the key to solve this problem,polyethylene glycol(PEG)and zwitterionic materials as a pioneer,has been widely research and application,however,they on fouling resistance and treatment efficiency and a lot of shortage,such as PEG susceptible to oxidation and so on,make it is limited by great in application,Amphoteric ions,on the other hand,have a lot of hindrance in post-modification.On the basis of the previous work,this paper further explored the anti-fouling materials of protein,and found that the main anti-fouling materials of protein were serum albumin(BSA),while other anti-fouling materials of protein were rarely reported in the literature.By analyzing the anti-adsorption properties of different proteins,we found that the anti-adsorption ability of protein nanoparticles was related to the binding energy and hydrogen bond formation between materials,and a class of protein nanoparticles with both excellent anti-adsorption properties and good photodynamic and photothermal effects were screened out.The specific work of this paper is as follows:(1)Comparison of anti-protein adsorption properties of protein materials and their application in targeted therapyIn this paper,starch nanoparticles grafted with different proteins were prepared,which were starch nanoparticles(ST-NPS),starch nanoparticles grafted with casein(ST-CS NPS),starch nanoparticles grafted with soybean protein isolate(ST-SPI NPS),starch nanoparticles grafted with myoglobin(ST-MB NPS).Starch nanoparticles were grafted with water-soluble corn protein(St-Zein NPS)and starch nanoparticles grafted with gelatin(St-Gel NPS).The chemical structure,morphology and size of the nanoparticles were characterized by Fourier transform infrared spectroscopy(FTIR),nano-particle size analyzer(DLS)and scanning electron microscopy(SEM).Nanoparticles co-incubated with fetal bovine serum(FBS)were further analyzed by liquid mass spectrometry(LC-MS)to detect their anti-protein adsorption capacity.In addition,this chapter also simulated the interaction between different proteins and serum proteins through molecular docking simulation to analyze the reasons for the differences in anti-serum protein adsorption ability of different proteins,and screened out the best St-Cs NPs and the worst St-Gel NPs with anti-fouling ability.Then,using casein and gelatin as emulsifiers and methyl methacrylate as monomers,casein nanoparticles(CS-Em NPS)and gelatin nanoparticles(Gel-Em NPS)were synthesized by emulsion polymerization.The chemical structure,morphology and size of the nanoparticles were characterized by nano-particle size analyzer,scanning electron microscope,liquid-mass spectrometry,etc.Quantitative analysis of the nanoparticles themselves and the adsorbed proteins showed that casein nanoparticles had the best comprehensive properties of protein adsorption resistance,stability,particle size and so on.Finally,casein nanoparticles were loaded with photosensitizer and were coupled with nucleic acid apharmers.Through laser confocal,singlet oxygen determination of photosensitizer loaded nanoparticles and cell apoptosis experiments,the ability of casein nanoparticles to target cell recognition and kill cancer cells was tested.Experimental results showed that casein have excellent ability to resist pollution,at the same time,the preparation of nanoparticles by emulsion polymerization with more superior than graft preparation of nanometer particles fouling resistance and stability,and can be through the EDC-method for the coupling of the NHS nucleic acid adaptation,make its have the ability to target and on its load after photodynamic drugs,It can release singlet oxygen and play a role in the treatment of tumor.It has an ideal practical application prospect.(2)Study on the photothermal properties of casein nanoparticles supported photothermal agentsOn the basis of the previous chapter,and continue to explore the casein nanoparticles in the treatment of field application prospect and the two different doses of field(ICG,IR-775)load to casein graft starch nanoparticles,the particle size analyzer,infrared thermal imager,ultraviolet spectrophotometer and fluorescence analyzer on the particle size of nano particles,structure,thermal properties,The results show that the nanoparticle prepared by this method fails to show considerable photothermal properties.Then,the nanoparticle can be improved by using ICG itself to have a special and stable interaction with protein.ICG was directly adsorbed on casein nanoparticles(CS-EM-TPPOH NPS)loaded with photosensitizer tetrahydroxyphenyl porphyrin(TPPOH)and on nanoparticles(CS-EM NPS)unloaded with TPPOH.And continue to adsorb a layer of casein and FBS on the outer layer of CS-EM-TPPOH-ICG NPS and CS-EM-ICG NPS.The particle size,centrifugal stability,anti-protein adsorption capacity and photothermal properties of casein nanoparticles coated with FBS or casein shells and loaded with ICG and TPPOH were compared with those coated with FBS or casein shells and only loaded with ICG.The experimental results showed that,compared with other nanoparticles,Packages casein shell and only load of ICG casein nanoparticles emissions performance is more outstanding,the highest light within 5 min temperature up to 62 ℃,and the ability to resist protein adsorption and centrifugal stability is better,so the parcel casein shell and load ICG casein nanoparticles become the best choice of the application and heat treatment,It has a good prospect in the practical application of photothermal therapy.