Screening Of Penetrating Peptides And Preparation And Research Of Insulin Penetrating Peptide Nanoparticles

Background:Insulin is the drug of choice for the current control and treatment of diabetes,long-term injection of insulin to diabetic patients with physical and psychological has brought a lot of pain.So,non injecting preparations of insulin is the direction of the efforts of many scholars,however,of the special nature of their own insulin:easy to be enzymatic hydrolysis,second cell membrane barrier function,these two restricts the development of non injection insulin preparation.Nanoparticles as a novel drug carrier.At present,it is widely used to increase drug absorption studies,of course,also contains insulin,and chitosan as preparation of insulin nanoparticles materials without a lot of material advantages,it has a good mucoadhesive property,compatibility,security and degradation,but also increase the insulin loading,promote insulin absorption.Cell penetrating peptide(CPP)is in recent years was found to be a potential drug carrier,has the very strong cell penetrating ability and low concentrations of cells almost no toxicity and can carry than its relative molecular mass of 100 times the exogenous macromolecules into cells and high carrying efficiency.Eight poly arginine(R8),as a typical cell penetrating peptide,has many advantages,which has good application prospects in overcoming the barrier function of cell membrane to insulin.If you can combine the two carriers with the membrane peptide and the nanoparticles,the potential is huge.Aim:R8 as a cell penetrating peptide can as a drug carrier for insulin,but of R8 modified improved research less,the experiment of R8 modified replaced with different amino acids,and then the stearic acid(SA)was chemically modified,to study the modification of the two pro of lipopeptides(SAR6EW)to enhance the role of insulin absorption and mechanism of,and will wear membrane peptides and nanoparticles with and research of prepare insulin to wear the feasibility of membrane peptides nanoparticles.Methods:1.The chitosan,sodium tripolyphosphate(STPP)as the main material through ion exchange to prepare insulin loaded chitosan nanoparticles,using scanning electron microscopy(SEM),laser particle size analyzer,Fourier transform infrared spectroscopy(FTIR),thermogravimetric analyzer of nanoparticles on appearance observation and characterization of detection,drug loading nanoparticles was,encapsulation rate and drug release.2.With different amino acid substitutions R8,then sa the were chemically modified,using circular dichroism(CD)to study the effects of insulin complex secondary structure,R8 and derivatives and insulin action was measured by isothermal titration calorimetry(ITC),and R8 and its derivatives in overcoming the enzyme hydrolysis,enhanced cellular uptake and toxicity of advantage.3.To prepare insulin loaded chitosan nanoparticles as the main material prepared chitosan insulin-wear membrane peptide nanoparticles,and by using scanning electron microscopy(SEM),laser particle size analyzer,Fourier transform infrared spectroscopy(FTIR)and X-ray diffraction of cell penetrating peptide nanoparticles morphology and characterization of detection.Results:1.Preparation of insulin chitosan nanoparticle shape is globose,the edge is smooth and round,the average particle size of less than 100 nm,drug loading,encapsulation efficiency,release quantity 2 hours,24 hours of the drug release and the of FTIR and TGA analysis also confirmed that chitosan and pancreatic island element formed nanoparticles.2.R8 and its derivatives R6EW,insulin did not change the secondary structure of adding SAR6EW.By modification of the SAR6EW compared to R8 and R6EW can significantly improve the absorption of insulin,and insulin binding is more stable,reduce insulin enzymolysis,and on the cells have no significant toxicity.3.The prepared insulin chitosan-penetrating peptide nanoparticles were spherical in shape,spherical in shape,and round in shape.The particle size was mainly distributed in the 80-100nm range,and the analysis of FTIR and X-diffraction confirmed that the particle size was also confirmed by the addition of the cell penetrating peptide.Conclusion:This topic is discovered and proved.Compared with the modified SAR6EW in R8 and R6EW can make better insulin absorption and no cytotoxicity,also discussed the possible mechanisms of SAR6EW.Also successfully prepared chitosan nanoparticles of insulin,and two kinds of nanoparticles and peptide drug carrier combined with nanoparticles were successfully prepared by cell penetrating peptides.