Enhanced anti Pseudomonas aeruginosa efficacy of niosomal-encapsulated Frondoside A from sea cucumber: a novel biotechnological approach

Pseudomonas aeruginosa ( P. aeruginosa) forms persistent biofilms that limit antibiotic efficacy. Frondoside A, a triterpenoid glycoside from sea cucumbers, possesses antimicrobial potential but suffers from poor solubility and stability. This study aimed to enhance its antibacterial and anti-biofilm activities via niosomal encapsulation and to assess its effect on biofilm-related gene expression. Niosomal Frondoside A was synthesized by thin-film hydration and characterized for size, charge, and encapsulation efficiency. Antibacterial activity was determined using agar diffusion and MIC/MBC assays, while biofilm inhibition was quantified by crystal violet assay. Expression of GacS and PslA was analyzed by qRT-PCR with 16 S rRNA as an internal control. The optimized niosomes had a zeta potential of − 8.6 mV, and 78 ± 0.408% encapsulation efficiency. Compared to the free drug, the niosomal formulation reduced MIC/MBC values from 6.25/12.5 mg mL⁻¹ to 1.56/3.125 mg mL⁻¹, enlarged inhibition zones by 45–60%, and decreased biofilm biomass by 68–79% ( p < 0.001). Furthermore, qRT-PCR showed significant downregulation of GacS and PslA genes. Niosomal encapsulation markedly improves the antimicrobial and gene-suppressive efficacy of Frondoside A, offering a potent nanocarrier approach against multidrug-resistant P. aeruginosa biofilms.