Effects Of Molecular Interactions On The Characteristics Of Drug-loaded Zein Nanoparticles

This study investigated the interaction between zein and vitamin D3,curcumin,quercetin,vitamin A acid,prednisolone and ibuprofen,respectively.Possible effects of interactions between zein and hydrophobic drugs on drug-loading characteristics were discussed,and zein nanoparticles encapsulating the corresponding drugs were prepared,characterized and optimized.Fluorescence spectroscopy was used to study the fluorescence quenching between zein and six hydrophobic drugs.The results showed that there was fluorescence quenching between vitamin D3,curcumin,quercetin and zein,all of which were static quenching.There is no fluorescence quenching between vitamin A acid,prednisolone,ibuprofen and zein.The number of binding sites and binding constants of vitamin D3,curcumin,quercetin and zein were studied,and the non-covalent interaction between vitamin D3,curcumin and zein was mainly determined by hydrophobic interaction and van der Waals force.The interaction between quercetin and zein is mainly for hydrophobic interactions and electrostatic interactions.Secondly,the zein nanoparticles encapsulating the above hydrophobic drugs were prepared by phase separation method.The particle size,thermal stability,drug loading,encapsulation efficiency and the cumulative release of drugs in PBS(pH7.4)encapsulation efficiency of the six nanoparticles were investigated.The results showed that the drug-loaded nanoparticles with interaction between zein and drugs and the drug-loaded nanoparticles without interaction had significant differences in drug release properties.The interaction of zein nanoparticles showed better sustained release characteristics,and the cumulative drug release amount of quercetin nanoparticles and curcumin nanoparticles was 8.24%and 5%within 8 h,respectively,and the drug release rate was constant within 8 h.The zein nanoparticles containing prednisolone,ibuprofen,and vitamin A acid reached a drug release equilibrium within 0.5 h and released more than half of the loaded drug.Finally,quercetin was used as a model drug to optimize the preparation conditions of quercetin-loaded zein by investigating the effects of zein concentration and zein/quercetin mass ratio on the properties of drug-loaded nanoparticles.The results showed that the zein particle size increased with the increase of zein concentration,and the encapsulation efficiency decreased with the increase of zein concentration.The cumulative drug release was highest with 4%concentration of zein..The effect of the mass ratio of zein/quercetin on the particle size of nanoparticles is not significant,but it has a significant effect on the cumulative release rate of quercetin in drug-loaded nanoparticles.As the ratio increases,the nanoparticles cumulative release rate increased from 5.8%to 19.7%.In summary,when zein is used as a drug delivery system,its drug release properties are affected by the interaction between the drug molecule and zein.