Immobilization of beneficial vaginal lactobacilli in polymeric nanofibers for its potential inclusion in vaginal probiotic formulations

SILVA JESSICA ALEJANDRA; DE GREGORIO PRISCILLA ROMINA; RIVERO GUADALUPE; ABRAHAN GUSTAVO ABEL; MARÍA ELENA FÁTIMA NADER-MACÍAS

Mar del Plata

Congreso; Congresos SAFE Asociación Argentina de Farmacología Experimental; 2019

Lactobacilli are the predominant microorganisms in the vaginal microbiome of healthy women. Probiotic formulations containing lactobacilli must include a high number of viable and active microorganisms. The aim of this work was to evaluate the compatibility, survival and maintenance of beneficial properties of Lactobacillus gasseri CRL1320 and L.rhamnosus CRL1332 during their immobilization in polymeric nanofibers (by electrospinning) and after storage. The compatibility of lactobacilli with mucoadhesive polymers [polyvinylalcohol (PVA), polyvinylpyrrolidone (PVP) and chitosan/polyethylene oxide (Quit/PEO)] were evaluated. Lactobacilli were immobilized in nanofibers with PVA through the application of flow rate, 0.01mm/s; tip to collector distance, 12 cm; and voltage, 12 kV, and later stored at room temperature, 4°C and at -20°C. Lactobacillus viability, the maintenance of beneficial properties (hydrophobicity, self-aggregation and antimicrobial activity against urogenital pathogens) and nanofibers morphology were determined by electron-microscopy (SEM) andinfrared spectroscopy (FTIR). The lactobacilli combined with PVA and PVP does not affect its viability, while Quit/PEO mixture was non-compatible. Therefore, PVA was selected for the immobilization. Electrospinning process was efficient since it allowed the recovery of a high number of lactobacilli (1010 UFC/g) per nanofiber without modifying the surface and antimicrobial properties of the two microorganisms. The Lactobacillus incorporated into nanofibers was evidenced by SEM and FITR. A higher survival rate was obtained in L. rhamnosus CRL1332 than in L. gasseri CRL1320 after the immobilization. The highest numbers of viable cells were obtained in nanofibers stored at -20°C. However, a decrease of viable cells (lower than 1 x107 CFU/g) was produced in L. gasseri CRL1320 and L. rhamnosus CRL1332 at 28 and 56 days, respectively. The results obtained support the inclusion of vaginal lactobacilli into polymeric nanofibers for the design of vaginal formula. However, further studies are being carried out to improve the Lactobacillus survival in polymeric nanofibers