Sexually transmitted infections (STIs) affect millions daily worldwide, disproportionately affecting women at twice the risk. Inconsistent condom use contributes to this alarming rate. Tremendous efforts are made to develop condom-free prophylaxis and to treat infected individuals, creating a significant burden on society and healthcare. Importantly, these efforts lead to antimicrobial resistance development. Currently, only two vaccines (HBV and HPV) exist. HIV and HSV are major STI epidemics. 40 million people worldwide are living with HIV. Individuals who are carriers of HSV have a fourfold increased risk of contracting HIV.
Condom-free prophylaxis against HIV have been developed, such as drug-based PrEP, which can cost EURO 28,000 per year without insurance. Therefore, people who are most at risk in low-income countries do not have access to it. In addition, levels of protection among women have been inconsistent, ranging from −49 to 76%, and side effects and drug resistance can occur. Currently, there are no products on the market with clinically validated claims for lubricants with prophylactic activity against STIs.
Nature offers valuable insights into viral protection, such as epithelial mucus coatings and dipeptides in HIV-infected Elite Controllers. The human vagina, lined with cervicovaginal mucus (CVM), scavenges HIV under acidic conditions. However, CVM pH turns neutral during the menstrual cycle and post-ejaculation, reducing its protective capacity. In addition, sialic acids on mucins of CVM are degraded in individuals infected with bacterial vaginosis (BV); here, the bacteria produce sialidases, which entail the degradation of CVM.In HIV-infected Elite Controllers, certain dipeptides enriched in blood plasma and feces, compared to HIV-1 progressors and HIV-negative individuals, act as inhibitors of HIV replication in infected cells, without antiretroviral therapy.
NatProLub aims to harness these mechanisms to develop lubricants for effective HIV and HSV prophylaxis, and even broader STIs, where natural mechanisms fall short, as an alternative or complement to condoms, and addressing gender imbalances in sexual health and avoiding the risk of developing antimicrobial resistance.
We establish protocols to extract high-quality mucins from various sources and develop innovative gels that mimic natural mucus, offering enhanced infection prophylactic efficacy when used as lubricate. These gels transition between states, liquefying during intercourse to provide lubrication and rapidly solidifying at rest to trap and immobilise viruses, facilitating their removal through natural excretion. Additionally, we enrich these gels with antiviral agents that can be released to penetrate the mucus barrier. These antivirals aim to inhibit HIV replication during the acute phase of infection, targeting any escaped virus. Safety and antiviral efficacy and antiviral mechanisms are rigorously evaluated using various models, including non-human primates.
