Fabrication and optimization of amoxicillin-loaded niosomes:An appropriate strategy to increase antimicrobial and anti-biofilmeffects against multidrug-resistant strains of Staphylococcus aureus

Background and Aim : In this study, different formulations of amoxicillin-loaded niosomes werefabricated using the thin-film hydration method and their physicochemical properties weredetermined using scanning electron microscopy (SEM), dynamic light scattering (DLS), andFourier-transform infrared spectroscopy (FTIR). The optimum prepared niosomes had a sphericalmorphology with an average size of ۱۷۰.۶±۶.۸ nm and encapsulation efficiency of ۶۵.۷۸±۱.۴۵%Methods : he drug release study showed that the release rate of amoxicillin from niosomecontaining amoxicillin was slow and ۴۷±۱% of the drug was released within ۸ hours, while۹۷±۰.۵% of the free drug was released. In addition, amoxicillin-loaded niosome increased theantimicrobial activity by ۲-۴ folds against multidrug-resistant (MDR) Staphylococcus aureusstrains using broth microdilution assay. Moreover, at ½ minimum inhibitory concentrations,amoxicillin-loaded niosome significantly enhanced the anti-biofilm activity compared to freeamoxicillin. Amoxicillin-loaded niosome had negligible cytotoxicity against HEK-۲۹۳ normal cellline compared to free amoxicillin. The free niosomes exhibited no toxicity against HEK-۲۹۳ cellsand presented a biocompatible nanoscale delivery system. Based on the results, it can be concludedthat amoxicillin-loaded niosome can be used as a promising candidate for enhancing antimicrobialand anti-biofilm effects against MDR strains of S. aureus.Results : All the noisome formations were prepared based on the Design of Experiments describedin Table ۱. Influence of various variables such as surfactant: Span ۶۰: Tween ۶۰ and cholesterolon the entrapped efficiency percentage and the size of noisome are shown in . The niosome sizeranging ۱۷۰.۶±۶.۸– ۲۴۸.۵±۱.۷ nm and entrapment efficiency (EE %) ranging ۴۵.۳۶±۱.۱–۶۵.۷۸±۱.۴۵% were achieved. The ۱:۱ and ۵۰:۵۰ molar ratio of cholesterol and Span ۶۰: Tween ۶۰resulted in smaller niosomes with high EE%. The optimum niosome formulation was successfullyfabricated and their physicochemical was determined for the desired criteria based on theexperimental design. The optimized formulation particle size is ۱۷۰.۶±۶.۸ nm, and the EE%۶۵.۷۸±۱.۴۵ %Conclusion : In this study, various niosome formulations containing amoxicillin were fabricatedand their antimicrobial and anti-biofilm effects were investigated. Our findings demonstrated thatamoxicillin-containing niosome reduce antimicrobial effects by ۲ to ۴ times and had biofilminhibitory effects against multidrug-resistant Staphylococcus aureus strains compared to freeamoxicillin. The results of cytotoxicity also demonstrated that amoxicillin-loaded niosomesreduced the cytotoxicity of amoxicillin. According to the results of this study, it can be concludedthat niosome is a suitable drug delivery system for antimicrobial purposes

کلیدواژه ها:

Amoxicillin ، Niosome ، Staphylococcus aureus ، Antimicrobial ، Anti-biofilm