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; ABRAHAM, GUSTAVO A.; NADER-MACIAS, MARIA ELENA FATIMA

Mar del Plata

Simposio; Reunión anual de Sociedades de Biociencias - Asociación Argentina de Farmacología Experimental (SAFE) 2019; 2019

Lactobacilli are the predominant microorganisms in the vaginal microbiome of healthy women.Probiotic formulations containing lactic acid bacteria (LAB) must include a high number of viable and active bacteria. The aim of this work wasto evaluate the compatibility, survival and maintenance of beneficial properties of Lactobacillus gasseriCRL1320 and L.rhamnosusCRL1332 during their immobilization in polymeric nanofibers by electrospinningand after storage.The compatibility of lactobacilliwithmucoadhesivepolymers [polyvinylalcohol (PVA), polyvinylpyrrolidone (PVP) and chitosan/polyethylene oxide (Quit/PEO)] were evaluated.Lactobacilli were electrospunnedwith 15% w/v PVA (12 kV, 0.3 mL/h, 12 cm distance to aluminum collector).The membranes were later stored at room temperature, 4°Cand at -20°C. Lactobacillus viability,maintenance of beneficial properties (hydrophobicity, self-aggregation and antimicrobial activity against urogenital pathogens) andnanofiberscharacterization was performed by SEM and FITR. Thecombination of PVA and PVP does not affect the bacteria viability, while Quit/PEO mixture was non-compatible. Therefore, PVA was selectedfor LAB immobilization.Electrospinning process was efficient since it allowedthe recovery of a high number of lactobacilli (1010 UFC/gnanofiber) without modifying the surface and antimicrobial properties of the two strains.Lactobacillusimmobilized in nanofiberswere evidenced by SEM and FTIR. A higher survival rate was obtained in L. rhamnosus CRL1332 than inL. gasseriCRL1320 after the immobilization. The highest viable cellswere keptin nanofibers stored at -20°C.However, a decrease of viable cells (lower than 1 x107 CFU/g) was observedin L. gasseri CRL1320 and L. rhamnosus CRL1332 at 28 and 56 days, respectively. Theresults obtainedsupport the inclusion of lactobacilli intopolymeric nanofibers for the design of vaginal formula. However, furtherstudies are being carried out to improve the Lactobacillus survival.