The Preparation Of Arsenic Trioxide-loaded Polylactic Acid Nanoparticles And Its Inhibiting Effect On Tumor Cells

[Object]Arsenic trioxide(As2O3)detection method had been established,the polylactic acid,polyethylene glycol-modified polylactic acid were used for the preparation of As2O3 nanoparticles.Nanoparticles form,particle size,drug loading and encapsulation efficiency were characterized;release behaviors of nanoparticles in vitro were being studied.Nanoparticles safety were evaluated.Pharmacokinetic behavior in rats after tail vein injection were researched.In order to analyze nanoparticles in vitro efficacy of cancer cells and resistant cells reversal index,arsenic trioxide nanoparticles were used for cytological experiments..[Method]Hydride Generator-atomic absorption spectrometry was used to establish the detection method of As2O3;Double emulsion solvent evaporation method was used for the preparation of nanoparticles of arsenic trioxide(As2O3-PLA-NPs,As2O3-mPEG-PLA-NPs),according to L9(34)orthogonal test prescription,best encapsulation efficiency was determined as the marker process and verify;redispersibility,encapsulation efficiency and appearance were used to determine the optimum process lyophilized nanoparticles,stability was investigated by transmission electron microscope,to observe nanoparticles morphology,particle size analyzer was used to determine the potential of nanoparticles and determine the particle size distribution;dynamic dialysis method was used to analyze trends of As2O3-NPs in vitro release.Nanoparticles were investigated in rats in vivo pharmacokinetics,DAS2.0 was used to fit the parameters.CCK-8 method was used to study the toxicity of nanoparticles on cells and the reversal of MCF-7/ADR;Annexin V-FITC/PI double staining and flow cytometry were used to detect arsenic trioxide nanoparticles on cell withered induction of apoptosis;PI staining flow cytometry block of As2O3-NPs on MCF-7/ADR cycle was used for testing.[Results]As2O3-PLA-NPs particle size was 133.2±5nm,encapsulation efficiency was 91.75 ± 0.38%,Zeta potential is-7.11mV;As2O3-mPEGPLA-NPs particle size was 123.4±6nm,encapsulation efficiency was 86.32±0.54%,Zeta potential is-6.7mV.Nanoparticles were observed under transmission electron microscope,the results show that their shape was spherical,similar in size,good dispersion,with a light blue opalescent solution.When mannitol was used as lyoprotectant,the result was the best;the stability of the lyophilized powder 6 months were examined,the results showed that the content of As2O3-PLA-NPs and As2O3-mPEG-PLA-NPs were dropped 3.62%and 3.05%respectively,indicating good stability of freeze-dried powder of nanoparticles.Nanoparticles in vitro release study results showed that both nanoparticles before 2h no burst release,all had a certain sustained release,wherein As2O3-PLA-NPs in 72h cumulative release was 64.84 ± 1.18%,As2O3-mPEG-PLA-NPs in the 72h cumulative release was 69.15 ± 1.43%;pharmacokinetic results showed that nano-vivo half-life extension of drugs,increased bioavailability,which As2O3-PLA-NPs group T1/2 was 1.52 times As2O3 saline group,AUC 1.42 times,As2O3-mPEG-PLANPs in vivo long circulating more significant effect,T1/2 of 2.53 times As2O3 saline group,AUC was 2.20 times;mPEG modified nanoparticles group T1/2 compared to the PLA nanoparticles group,a significant increase(*P<0.05).Cytology results showed that the group of drugs are able to inhibit the normal growth of resistant cells,apoptosis rate showed a concentrationdependent apoptosis nanoparticles group was higher than the free drug group;free drug group and the group were arrested nanoparticles cells were grown in G2/M phase,As2O3-mPEG-PLA-NPs block best.As2O3,As2O3-PLA-NPs,As2O3-mPEG-PLA-NPs as a reversal agent,ADM for MCF-7/ADR reversal multiples were 1.32,1.8,2.11.[Conclusion]The use of double emulsion solvent evaporation method,As2O3-PLA-NPs,As2O3-mPEG-PLA-NPs were successfully prepared,the method is simple and feasible,the particle size of nanoparticles was obtained by small and uniform,high encapsulation efficiency;in vitro release,pharmacokinetic aspects,mPEG modified nanoparticles exhibit better release effect;As2O3-PLA-NPs,As2O3-mPEG-PLA-NPs were on multidrug resistant breast cancer cells MCF-7/ADR have pro-apoptotic effect on the G2/M phase of cell growth arrest obviously,the reverse effect on MCF-7/ADR stronger than As2O3 drug.