Scientists have created a model “vagina on a chip” using cells grown inside silicone rubber chips – an advance that could help better understand the effects of bacterial communities on vaginal health.
While studies over the decades have assessed the effects of gut bacteria, the roles played by the bacterial community living in the vagina are “oft-ignored”, pointed out researchers, including those at Harvard University’s Wyss Institute.
Disruptions of the microbial community that lives in this organ can cause bacterial vaginosis (BV) – a disease that afflicts nearly 30 per cent of reproductive-aged women around the globe, costing about $4.8bn to treat annually, they said.
However, there are hurdles in conducting trials to find therapeutics against BV since the human vaginal microbiome is dramatically different from that of common animal models used in research.
In a new study, published recently in the journal Microbiome, scientists found a “breakthrough” solution to the problem in the form of a new chip that mimics the human vaginal tissue environment, including its communities of microbes.
“A major stumbling block for that effort was that there were no good preclinical models that could be used to study which therapies can actually treat BV in human tissues. Our team’s project was to create a human Vagina Chip to aid in the development and testing of new therapies for BV,” study co-author Aakanksha Gulati said in a statement.
The Vagina Chip consists of the human vaginal epithelium and underlying connective tissue cells.
To build the chip, scientists seeded the top channel of a polymer chip with human vaginal epithelial cells and added human uterine fibroblast cells that contribute to the formation of connective tissue.
Using this setup, researchers could replicate the 3D arrangement of the human vaginal wall.
Scientists said the new chip replicates many of the physiological features of the vagina and when inoculated with different strains of bacteria, can be used to study their effects on the organ’s health.
When they introduced the female sex hormone estradiol into the Vagina Chip, they found the chip’s gene expression patterns changed in response, indicating it was sensitive to hormones similar to a real vagina.
Researchers then introduced three different consortia containing several strains of the bacteria Lactobacillus crispatus which then successfully colonised the chips after three days.
The bacteria began producing lactic acid that helps to maintain the vagina’s low pH and inhibits the growth of other microbes.
Scientists then began introducing different species of bacteria associated with BV, such as Gardnerella vaginalis, Prevotella bivia and Atopobium vaginae.
They found that these “bad” bacteria caused the chips’ pH to increase, damaging the vaginal cells and increasing the production of multiple molecules linked to inflammations – responses similar to what is seen in human patients with BV.
“It was very striking that the different microbial species produced such opposite effects on the human vaginal cells, and we were able to observe and measure those effects quite easily using our Vagina Chip,” study co-author Abidemi Junaid said.
Researchers hope to use the Vagina Chip to find therapeutics that can decrease infections of the reproductive tract, prenatal complications and infant death rates.
“There is growing recognition that taking care of women’s health is critical for the health of all humans, but the creation of tools to study human female physiology is lagging,” study senior author Don Ingber said.
“We’re hopeful that this new preclinical model will drive the development of new treatments for BV as well as new insight into female reproductive health,” Dr Ingber added.
