PLGA–Chitosan Nanoparticles for Sequential Doxycycline–Cefixime Delivery against Salmonella Typhi
Abstract
Salmonella enterica serovar Typhi can persist in extracellular and intracellular niches, making typhoid fever difficult to treat when antimicrobial resistance narrows empirical options. This second model manuscript proposes a PLGA-chitosan dual nanoparticle platform for co-delivery of doxycycline and cefixime, designed to produce sequential release and improved intracellular exposure. PLGA was selected as a biodegradable core for sustained release, while chitosan was used as a cationic shell to improve mucoadhesion and cell interaction. Doxycycline was selected for intracellular protein-synthesis pressure and cefixime for extracellular cell-wall stress. The paper is structured as a Scopus-style research article with abstract, keywords, introduction, materials and methods, results, figures, tables, discussion, conclusion and references. All numerical outcomes are model data for academic drafting and must be replaced with validated experimental results before submission.
The optimized model nanoparticles had a mean size of 214.6 +/- 18.2 nm, PDI of 0.24 +/- 0.03, zeta potential of +24.7 +/- 2.9 mV and combined drug loading of 12.8 +/- 1.1%. Release was faster at pH 5.5 than pH 7.4, supporting a possible intracellular endosomal release advantage. In model antibacterial outputs, dual nanoparticles reduced intracellular S. Typhi burden from 6.2 log10 CFU/mL in untreated controls to 2.7 log10 CFU/mL after treatment, while free doxycycline plus cefixime reduced it to 4.6 log10 CFU/mL. Biofilm biomass decreased to 24% of untreated control, and mammalian-cell viability remained above 90%. These model findings suggest that a dual-compartment nanoparticle strategy may be useful for hypothesis-driven research on intracellular and extracellular typhoid control.
How to Cite
Dakshita, Rakesh Kumar, "PLGA–Chitosan Nanoparticles for Sequential Doxycycline–Cefixime Delivery against Salmonella Typhi", Vol. 4, Issue 1, 26-04-2026, pp. 105-115. DOI: 10.5281/zenodo.20768769
