New strategies for local treatment of vaginal infections

[Use of probiotics in bacterial vaginosis]

INTRODUCTION

Bacterial vaginosis (BV) is a change in the vaginal microbiota due to bacterial overgrowth of normal microorganisms, which produces symptoms of vaginal discomfort, increased malodorous vaginal discharge, etc. Although they been seen to improve recurrence rates in clinical practice, the role of probiotics is questioned in these situations. A literature review on BV is presented in order to evaluate the effectiveness of using probiotics as adjuvant therapy in BV.

METHOD

PubMed, Cochrane and SCOPUS review of the last 5 years publications using probiotics to treat women diagnosed with BV.

RESULTS

An analysis was performed on the 10 items that refer to the use of probiotics in addition to antibiotic treatments.

CONCLUSIONS

All items conclude that the use of probiotics is beneficial in cases of BV in addition to conventional treatments. However, the conclusions are not categorical due to there being a wide variety of studies and probiotics used.

Sulfonate-modified phenylboronic acid-rich nanoparticles as a novel mucoadhesive drug delivery system for vaginal administration of protein therapeutics: improved stability, mucin-dependent release and effective intravaginal placement

Effective interaction between mucoadhesive drug delivery systems and mucin is the basis of effective local placement of drugs to play its therapeutic role after mucosal administration including vaginal use, which especially requires prolonged drug presence for the treatment of gynecological infectious diseases. Our previous report on phenylboronic acid-rich nanoparticles (PBNPs) demonstrated their strong interaction with mucin and mucin-sensitive release profiles of the model protein therapeutics interferon (IFN) in vitro, but their poor stability and obvious tendency to aggregate over time severely limited future application. In this study, sulfonate-modified PBNPs (PBNP-S) were designed as a stable mucoadhesive drug delivery system where the negative charges conferred by sulfonate groups prevented aggregation of nanoparticles and the phenylboronic acid groups ensured effective interaction with mucin over a wide pH range. Results suggested that PBNP-S were of spherical morphology with narrow size distribution (123.5 nm, polydispersity index 0.050), good stability over a wide pH range and 3-month storage and considerable in vitro mucoadhesion capability at vaginal pH as shown by mucin adsorption determination. IFN could be loaded to PBNP-S by physical adsorption with high encapsulation efficiency and released in a mucin-dependent manner in vitro. In vivo near-infrared fluorescent whole animal imaging and quantitative vaginal lavage followed by enzyme-linked immunosorbent assay (ELISA) assay of IFN demonstrated that PBNP-S could stay in the vagina and maintain intravaginal IFN level for much longer time than IFN solution (24 hours vs several hours) without obvious histological irritation to vaginal mucosa after vaginal administration to mice. In summary, good stability, easy loading and controllable release of protein therapeutics, in vitro and in vivo mucoadhesive properties and local safety of PBNP-S suggested it as a promising nanoscale mucoadhesive drug delivery system for vaginal administration of protein therapeutics.

Orally administered multispecies probiotic formulations to prevent uro-genital infections: a randomized placebo-controlled pilot study

PURPOSE

The aim of this study was to evaluate in the vagina of 60 pre-menopausal women the detection of orally administered multispecies probiotic formulations showing anti-microbial properties in test in vitro.

METHODS

A randomized, double-blind, three-arm parallel pilot study was carried out on 60 pre-menopausal women. Subjects were randomly divided in three groups (F_1, F_2, F_3). Each group received a daily oral administration of probiotic mixtures (for 14 days and at the day 21, 7 days after the wash-out) containing: Lactobacillus acidophilus and Lactobacillus reuteri (F_1), or Lactobacillus plantarum, Lactobacillus rhamnosus and Bifidobacterium animalis subsp. lactis (F_2), or placebo (F_3), respectively. Vaginal swabs were collected at four experimental times, at t0 and at t7, t14 and t21 days, and analyzed by qPCR. At the same time, the anti-microbial activity of the probiotic formulations was verified by assays in vitro against microorganisms as Escherichia coli and Candida albicans.

RESULTS

L. acidophilus and L. reuteri as well as L. plantarum, L. rhamnosus and B. lactis were significantly increased on 7 days in the groups administered with F_1 and F_2, respectively, compared to group F_3. A similar significant trend was observed on 21 days, 7 days after the wash-out. F_1 and F_2 showed coherent anti-microbial properties.

CONCLUSION

Both probiotic formulations F_1 and F_2, chosen because of their anti-microbial activity against pathogens responsible for vaginal dysbiosis and infections, led to vaginal detection and enhancement of the amount of species of formulates when orally administered. This work provides the basis for further clinical investigations of the F_1 and F_2 capacity to prevent or treat uro-genital infections.

Freeze-dried mucoadhesive polymeric system containing pegylated lipoplexes: Towards a vaginal sustained released system for siRNA

Topical vaginal sustained delivery of siRNA presents a significant challenge due to the short residence time of formulations. Therefore, a drug delivery system capable to adhere to the vaginal mucosa is desirable, as it could allow a prolonged delivery and increase the effectiveness of the therapy. The aim of this project is to develop a polymeric solid mucoadhesive system, loaded with lipoplexes, able to be progressively rehydrated by the vaginal fluids to form a hydrogel and to deliver siRNA to vaginal tissues. To minimize adhesive interactions with vaginal mucus components, lipoplexes were coated with different derivatives of polyethylene glycol: DPSE-PEG2000, DPSE-PEG750 and ceramide-PEG2000. Based on stability and diffusion properties in simulated vaginal fluids, lipoplexes containing DSPE-PEG2000 were selected and incorporated in hydroxyethyl cellulose (HEC) hydrogels. Solid systems, called sponges, were then obtained by freeze-drying. Sponges meet acceptable mechanical characteristics and their hardness, deformability and mucoadhesive properties are not influenced by the presence of lipoplexes. Finally, mobility and stability of lipoplexes inside sponges rehydrated with vaginal mucus, mimicking in situ conditions, were evaluated by advanced fluorescence microscopy. The release rate was found to be influenced by the HEC concentration and consequently by the viscosity after rehydration. This study demonstrates the feasibility of entrapping pegylated lipoplexes into a solid matrix system for a prolonged delivery of siRNA into the vagina.

Screening of Compounds against Gardnerella vaginalis Biofilms

Bacterial vaginosis (BV) is a common infection in reproductive age woman and is characterized by dysbiosis of the healthy vaginal flora which is dominated by Lactobacilli, followed by growth of bacteria like Gardnerella vaginalis. The ability of G. vaginalis to form biofilms contributes to the high rates of recurrence that are typical for BV and which unfortunately make repeated antibiotic therapy inevitable. Here we developed a biofilm model for G. vaginalis and screened a large spectrum of compounds for their ability to prevent biofilm formation and to resolve an existing G. vaginalis biofilm. The antibiotics metronidazole and tobramycin were highly effective in preventing biofilm formation, but had no effect on an established biofilm. The application of the amphoteric tenside sodium cocoamphoacetate (SCAA) led to disintegration of existing biofilms, reducing biomass by 51% and viability by 61% and it was able to increase the effect of metronidazole by 40% (biomass) and 61% (viability). Our data show that attacking the biofilm and the bacterial cells by the combination of an amphoteric tenside with the antibiotic metronidazole might be a useful strategy against BV.