Study On Preparation Technique Of Quercetin-Loaded Nanoparticles

Nanotechnology has been applied in various medical fields comprising drug delivery system,providing intelligent systems,devices and materials for improved pharmaceutical applications.Nanoparticles,were also found to have enormous application in biomedical and pharmaceutical fields.In this paper,quercetin,a poorly water-soluble drug,was used as model drug.Quercetin nanoparticles were prepared by ionic gelation technique coated with chitosan-alginate in order to increase solubility of quercetin,as so to improve its bioavailability.In this experiment,quercetin nanoparticles were prepared by ionic gelation method.UV-visible spectrophotometry was used to measure the entrapment efficiency and drug loading of quercetin nanoparticles.Single factor method was used to optimize the preparation process of quercetin nanoparticles.Dynamic light scattering(DLS)were used to measure particle size and Zeta potential of the nanoparticles.The morphology of the nanoparticles was observed using transmission electron microscopy.The dialysis method was used to measure the drug release in vitro of nanoparticles,and the multi-index comparison was used to determine the lyophilization process of nanoparticles.The inhibitory effect of quercetin nanoparticles on the proliferation of HepG2 cells and the IC50 was determined by MTT assay.By comparing the appearance,entrapment efficiency and drug loading of nanoparticles of various formulation,the optimal concentration and dosage of each drug and the optimal preparation conditions in the preparation process were optimized.The encapsulation efficiency of quercetin nanoparticles obtained by the best process was 96.70±1.11%,and the drug loading was 12.25±0.54%.The average particle size of the nanoparticles was 164.5 nm and the Zeta potential was-19.3 mV.The nanoparticles were nearly spherical and its distribution was uniform.The cumulative release rate reached more than 80%after 24 h.To compare the appearance,color and the dispersivity of freeze-dried powder,2%lactose was selected as the cryoprotectant of quercetin nanoparticles freeze-dried powder.The powder got a full appearance,color uniformity,no shrinkage and good dispersion freeze-dried powder.After lyophilized powder,were reconstituted,morphology of nanoparticels were observed by transmission electron microscope appearing little of adhesion.The average size of nanoparticles was 281.8 nm.The Zeta potential was-12.7 mV.The encapsulation efficiency of nanoparticles was 97.84%.The drug loading capacity of nanoparticles was 9.26%.The MTT assay results showed that,IC50 of quercetin to HepG2 cells treated with hepatoma cells at 48 h and 72 h was 99.61 ?g/mL and 24.41 ?g/mL,respectively,while that of quercetin nanoparticles was 78.33 ?g/mL and 14.93 ?g/mL.Blank nanoparticles have no obvious inhibitory effect.It supposed that quercetin nanoparticles had higher inhibition effects on HepG2 than pure quercetin.In conclusion,the quercetin nanoparticles prepared by the ion-gel method have the advantages of high encapsulation efficiency,small particle size and uniform distribution,improved solubility of quercetin and enhanced inhibition of tumor cells.It provided a reliable drug delivery system of quercetin for its tumor treatment in clinic.