Reseach On Preparation And Pharmacokinetics Of PH-response Curcumin Nano Micelle

Curcumin is a kind of natural polyphenols,derived from Zingiberaceae plants of Curcuma rhizome.Pharmacological studies proved that curcumin has anticarcinogenic,antioxidative,anti-inflammatory,reducing blood sugar,inhibit angiogenesis,Anti tumor migration and other activities.Toxicology studies showed that curcumin is almost noN-toxic side effects,it is still safe at high doses.Although as an anti-cancer chemotherapy drug,curcumin has many potential advantages,but it also has many disadvantages,hydrophilic and lipophilic deviation,solubility minima,almost insoluble in water,low oral bioavailability,physiological value not stable,fast metabolism,to light and heat not stable.All these have greatly limited the clinical application of curcumin.The current research of curcumin focused on structural changes or new formulations for its application.Polymeric micelle is a novel preparation,which is prepared by amphiphilic polymers in aqueous solution reaches a certain concentration,through electrostatic interaction,intermolecular hydrogen bonding and van der Waals force spontaneous,its formation has typical core-shell structure delivery micelles.The micelle shell is hydrophilic,and the core is composed of a hydrophobic block,which can be a hydrophobic reservoir.Compared with other drug carrier system,nano micelle preparation can obviously improve the pharmacological activity of curcumin and improve the water solubility and increase the bioavailability,and the micelle particle diameter is small,the load at high doses,and surface can also be modified.At present,many scholars reported nano micelles,liposomes,inclusion and polymer preparation of curcumin,these agents have a good prospect of clinical application.Tumor tissue intercellular matter showed a weak acid(pH<7)and endosomes in tumor cells and lysosomes have stronger acidic(pH 4 ~ 6).The pH response of the core or shell of the polymer micelle can be protonated or fast chemical reaction under acidic pH of the tumor,which leads to the change of its physical properties.Micelles of tumor acidic pH response function can be used to achieve drug fast release,activation of the target function of micelles,promotes micellar cell endocytosis,and prompted the micelles from lysosomal escape to cytoplasmic solutes and target to the nucleus and other organelles.A large amount of experiments in vivo and in vitro showed that the pH responsive conveying anticancer drugs micelle type can significantly increase the concentration of cytoplasm and nucleus,breakthrough a variety of mechanisms of drug resistance in cancer cells,thereby overcoming the drug resistance of tumor cells,improve the treatment efficiency of the anticancer drug and reduce its toxic side effects.Poly histidine-polyethylene glycol(PHis-PEG)copolymers micelles have unique pH response,is very effective in mice sensitive and resistant solid tumors.Histidine end of micelles exhibit a pH sensitivity by pH decreased,and would be active uptaked by cancer cells,and induced in cancer cells pH,triggering the micelle physical disintegration.The ionization of the histidine side helps to reduce the intracellular overflow and to increase the concentration of cancer cells and to reduce the noN-specific biological distribution,so as to achieve the purpose of specific treatment of tumors.In this paper,we study the preparation of nano micelles containing curcumin by poly(histidine glycol)(PHis-PEG)copolymer,and study its drug release characteristics in vitro and pharmacokinetics in vivo.Part 1 Preparation and characterization of poly histidine glycol(PHis-PEG)copolymer.Objective: Preparation of poly histidine-polyethylene glycol(PHis-PEG),and characterization of the preparation product by nuclear magnetic.Methods: Synthesis of poly histidine-polyethylene glycol(PHis-PEG): N-carbobenzoxy-N-(2,4-dinitrophenyl)2 histidine(N-CBZ-N-DNP-2-histidine)monomer with thionyl chloride processing to generate N-carboxyl-ring anhydride and N-(2,4-dinitrophenyl)-L-histidine hydrochloride(N-DNP-L-histidine carboxyanhydride hydrochloride(DNPH-NCA)),followed by amino terminated polyethylene glycol(PEG2000-NH2)triggered DNPH-NCA opeN-loop polymerization polymerization with different degrees of poly(ethylene glycol)-poly(2,4-dinitro phenyl-histidine)and finally 2-mercaptoethanol role off 2,4-dinitrophenyl generate different degrees of polymerized poly histidine-polyethylene glycol(PHis-PEG).Results: The obtained PHis-PEG was determined by 1H-NMR,and its structure was proved to be correct.Conclusion: This synthesis method is simple and feasible,and the PHis-PEG is successfully synthesized.Part 2 Preparation of curcumin loaded micelles and Study on its physical and chemical propertiesObjective: Preparation of curcumin PHis-PEG micelles,investigation of the micelle size and Zeta potential,the establishment of micellar drug loading determination by HPLC method.Methods: Under the condition of room temperature,add amount of CH2Cl2 to curcumin and PHis-PEG and then magnetic stirring to dissolve it completely,rotary evaporation to remove organic solvent CH2Cl2,and hybrid film formation of curcumin and carrier materials,thin film after vacuum drying oven drying thoroughly to remove residual organic solvents,get medical dry film.Film with right amount of normal saline was completely dissolved,obtained curcumin micelle suspension and centrifuged,the supernatan obtained is transparent and ontaining curcumin micelle solution.Finally,the concentrated curcumin micelle solution was determined by HPLC assay.Determination of micellar particle size and Zeta potential by dynamic light scattering method.Results: PHis-PEG is suitable for the loading of curcumin,and can play a role in solubilization of curcumin.Micellar particle size is 103.2nm,Zeta potential is about 15.36 mV,determination of drug loading is about 1.77 mg.ml-1 by HPLC.Conclusion: PHis-PEG is suitable for the loading of curcumin,and the drug loading is relatively high.Part 3 Investigation on the pH response and release characteristics of drug loaded micelles in vitroObjective: Test the in vitro pH response and release characteristics of curcumin loaded PHis-PEG nanoparticles.Methods: The morphology and particle size of the micelles with curcumin were observed in PBS buffer solution of different pH,and the concentration of Cur was measured at different time points,and the cumulative release rate of micelles was calculated.Results: The nano micelles in vitro are pH responsive;In similar physiological pH,there is no sudden release of curcumin loaded micelles,most of the curcumin micelle can stable for a long time,and in the decrease of the pH to 5.0,curcumin can be released quickly from micelles.Conclusion: PHis-PEG nano micelles loaded with curcumin in similar physiological pH environment is stable,can be quickly released in tumor and similar in weak acidic environment.Part 4 Pharmacokinetics of drug loaded micelles in vivoObjective: The blood drug concentration of curcumin and Cur-PPs nanoparticles loaded with curcumin were quantitatively determined by HPLC method.Methods: The Cur-PPs nano micelle solution containing curcumin was injected into the caudal vein of Wistar rats,blood samples were collected at various time intervals,and establish a HPLC method for determination of serum concentrationResults: Through the establishment of reliable HPLC method,accurate determination of the blood drug concentration of curcumin,drawing the curve of the drug time curve of the nano micelle,and getting the relevant pharmacokinetic parameters.Conclusion: The drug loaded nano micelles can prolong the retention time of curcumin in vivo,to achieve its long circulating in the blood,can be used for intravenous injection safely.