Study On Preparation And Anti-tumor Efficacy Of5-fluorouracil Loaded Chitosan Nanoparticles

Objective: To synthesize prodrug named N-methoxy poly （ethylene glycol）-chitosan-5-fluorouracil acetic acid conjugate（5-FU-CS-mPEG）;Toprepare5-FU-CS-mPEG nanoparticles; and evaluate their prescription、release in vitro and pharmacodynamics.Methods:5-FU-CS-mPEG was synthesized via two steps, first5-FU-CS wassynthesized by EDC/NHS, and the synthesis process was performed byorthogonal test, then the target product was acquired by modification withmPEG, the target products were identified by FT-IR、1H-NMR andDSC. Nanoparticles were prepared by ionotropic gelation method, thedrug loading was measured by UV, the particle size, polydispersity indexand Zeta potential were determined by dynamic light scattering, the shapeand morphology of nanoparticles were assessed by transmission electronmicroscope, the release in vitro of drug-loading nanoparticles were testedby dialysis and the release curves were fitted with different models.Preparation of H22liver entities KM mice, to evaluate antitumor activityand potential side effects of high、 medium、 low concentration of5-FU-CS-mPEG nanoparticles and mPEG-CS nanoparticles, after killingmices, the inhibition of tumor growth rate and thymus index, spleenindex were calculated by SPSS statistical software and tumor tissues weremade as HE staining slices. Results:5-FU-CS-mPEG was successfully synthesized, confirmed by infrared、1H-NMR and DSC; The optimal synthetic conditions of5-FU-CS were asfollows: the ratio of EDC·HCl and5-FUA was1.5to1, the ratio ofEDC·HCl and NHS was1to1, the ratio of5-FUA and CS was1to1, thereact time was1d. The drug loading efficiency of5-FU-CS-mPEGnanoparticle was4.2%, the average particle size of mPEG-CSnanoparticle and5-FU-CS-mPEG nanoparticle were169.2nm and259.8nm, Zeta potential of them were+42.55mv and+39.27mv, thedrug-loading nanoparticle was round or oval in shape. the drug-loadingnanoparticle showed sustained release behavior, the release in pH=5.5and in pH=7.2conformed to zero order equation and Weibull equationrespectively. The inhibition of tumor growth rate of drug-loadingnanoparticles of high、medium and low-dose groups were62.05%、48.79%and36.14%respectively, different doses of drug-loadingnanoparticle and free drug group were significantly higher thanphysiological saline group （P＜0.05）,but compared with free drug（5-FU）,there were no significant difference with drug-loadingnanoparticle of high dose（P＞0.05）,histopathology showed that agentsgroup were different degree of necrosis and apoptosis.Conclusions: Nanoparticle loaded with5-FU can be prepared by ionotropic gelationmethod, and its have round shape and ideal particle distribution; andthe drug-loading nanoparticle are showing sustained release in vivo andin vitro; and they have significant anti-tumor activity on mice.The5-FU-CS-mPEG nanoparticle is expected to be a potential carrier of5-FU.