Bioelectronic Medicine: a multidisciplinary roadmap from biophysics to precision therapies

Bioelectronic Medicine stands as an emerging field that rapidly evolves and offers distinctive clinical benefits, alongside unique challenges. It consists of the modulation of the nervous system by precise delivery of electrical current for the treatment of clinical conditions, such as post-stroke movement recovery or drug-resistant disorders. The unquestionable clinical impact of Bioelectronic Medicine is underscored by the successful translation to humans in the last decades, and the long list of preclinical studies. Given the emergency of accelerating the progress in new neuromodulation treatments (i.e., drug-resistant hypertension, autoimmune and degenerative diseases), collaboration between multiple fields is imperative. This work intends to foster multidisciplinary work and bring together different fields to provide the fundamental basis underlying Bioelectronic Medicine. In this review we will go from the biophysics of the cell membrane, which we consider the inner core of neuromodulation, to patient care. We will discuss the recently discovered mechanism of neurotransmission switching and how it will impact neuromodulation design, and we will provide an update on neuronal and glial basis in health and disease. The advances in biomedical technology have facilitated the collection of large amounts of data, thereby introducing new challenges in data analysis. We will discuss the current approaches and challenges in high throughput data analysis, encompassing big data, networks, artificial intelligence, and internet of things. Emphasis will be placed on understanding the electrochemical properties of neural interfaces, along with the integration of biocompatible and reliable materials and compliance with biomedical regulations for translational applications. Preclinical validation is foundational to the translational process, and we will discuss the critical aspects of such animal studies. Finally, we will focus on the patient point-of-care and challenges in neuromodulation as the ultimate goal of bioelectronic medicine. This review is a call to scientists from different fields to work together with a common endeavor: accelerate the decoding and modulation of the nervous system in a new era of therapeutic possibilities.

Validation of vaginal microbiome proxies for in vitro experiments that biomimic Lactobacillus-dominant vaginal cultures

The vaginal microbiome includes diverse microbiota dominated by Lactobacillus [L.] spp. that protect against infections, modulate inflammation, and regulate vaginal homeostasis. Because it is challenging to incorporate vaginal microbiota into in vitro models, including organ-on-a-chip systems, we assessed microbial metabolites as reliable proxies in addition to traditional vaginal epithelial cultures (VECs). Human immortalized VECs cultured on transwells with an air-liquid interface generated stratified cell layers colonized by transplanted healthy microbiomes (L. jensenii- or L. crispatus-dominant) or a community representing bacterial vaginosis (BV). After 48-h, a qPCR array confirmed the expected donor community profiles. Pooled apical and basal supernatants were subjected to metabolomic analysis (untargeted mass spectrometry) followed by ingenuity pathways analysis (IPA). To determine the bacterial metabolites' ability to recreate the vaginal microenvironment in vitro, pooled bacteria-free metabolites were added to traditional VEC cultures. Cell morphology, viability, and cytokine production were assessed. IPA analysis of metabolites from colonized samples contained fatty acids, nucleic acids, and sugar acids that were associated with signaling networks that contribute to secondary metabolism, anti-fungal, and anti-inflammatory functions indicative of a healthy vaginal microbiome compared to sterile VEC transwell metabolites. Pooled metabolites did not affect cell morphology or induce cell death (∼5.5%) of VEC cultures (n = 3) after 72-h. However, metabolites created an anti-inflammatory milieu by increasing IL-10 production (p = .06, T-test) and significantly suppressing pro-inflammatory IL-6 (p = .0001), IL-8 (p = .009), and TNFα (p = .0007) compared to naïve VEC cultures. BV VEC conditioned-medium did not affect cell morphology nor viability; however, it induced a pro-inflammatory environment by elevating levels of IL-6 (p = .023), IL-8 (p = .031), and TNFα (p = .021) when compared to L.-dominate microbiome-conditioned medium. VEC transwells provide a suitable ex vivo system to support the production of bacterial metabolites consistent with the vaginal milieu allowing subsequent in vitro studies with enhanced accuracy and utility.

Next generation 3D-printed intravaginal ring for prevention of HIV and unintended pregnancy

Globally, there are 20 million adolescent girls and young women living with HIV who have limited access to long-acting, effective, women-controlled preventative methods. Additionally, although there are many contraceptive methods available, globally, half of all pregnancies remain unintended. Here we report the first 3D-printed multipurpose prevention technology (MPT) intravaginal ring (IVR) for HIV prevention and contraception. We utilized continuous liquid interface production (CLIP™) to fabricate MPT IVRs in a biocompatible silicone-based resin. Etonogestrel (ENG), ethinyl estradiol (EE), and islatravir (ISL) were loaded into the silicone poly(urethane) IVR in a controlled single step drug loading process driven by absorption. ENG/EE/ISL IVR promoted sustained release of drugs for 150 days in vitro and 14 days in sheep. There were no adverse MPT IVR-related findings of cervicovaginal toxicity or changes in vaginal biopsies or microbiome community profiles evaluated in sheep. Furthermore, ISL IVR in macaques promoted sustained release for 28 days with ISL-triphosphate levels above the established pharmacokinetic benchmark of 50-100 fmol/106 PBMCs. The ISL IVR was found to be safe and well tolerated in the macaques with no observed mucosal cytokine changes or alterations in peripheral CD4 T-cell populations. Collectively, the proposed MPT IVR has potential to expand preventative choices for young women and girls.

Characterization of fetal microchimeric immune cells in mouse maternal hearts during physiologic and pathologic pregnancies

Introduction: During pregnancy, fetal cells can be incorporated into maternal tissues (fetal microchimerism), where they can persist postpartum. Whether these fetal cells are beneficial or detrimental to maternal health is unknown. This study aimed to characterize fetal microchimeric immune cells in the maternal heart during pregnancy and postpartum, and to identify differences in these fetal microchimeric subpopulations between normal and pregnancies complicated by spontaneous preterm induced by ascending infection. Methods: A Cre reporter mouse model, which when mated with wild-type C57BL/6J females resulted in cells and tissues of progeny expressing red fluorescent protein tandem dimer Tomato (mT+), was used to detect fetal microchimeric cells. On embryonic day (E)15, 104 colony-forming units (CFU) E. coli was administered intravaginally to mimic ascending infection, with delivery on or before E18.5 considered as preterm delivery. A subset of pregnant mice was sacrificed at E16 and postpartum day 28 to harvest maternal hearts. Heart tissues were processed for immunofluorescence microscopy and high-dimensional mass cytometry by time-of-flight (CyTOF) using an antibody panel of immune cell markers. Changes in cardiac physiologic parameters were measured up to 60 days postpartum via two-dimensional echocardiography. Results: Intravaginal E. coli administration resulted in preterm delivery of live pups in 70% of the cases. mT + expressing cells were detected in maternal uterus and heart, implying that fetal cells can migrate to different maternal compartments. During ascending infection, more fetal antigen-presenting cells (APCs) and less fetal hematopoietic stem cells (HSCs) and fetal double-positive (DP) thymocytes were observed in maternal hearts at E16 compared to normal pregnancy. These HSCs were cleared while DP thymocytes persisted 28 days postpartum following an ascending infection. No significant changes in cardiac physiologic parameters were observed postpartum except a trend in lowering the ejection fraction rate in preterm delivered mothers. Conclusion: Both normal pregnancy and ascending infection revealed distinct compositions of fetal microchimeric immune cells within the maternal heart, which could potentially influence the maternal cardiac microenvironment via (1) modulation of cardiac reverse modeling processes by fetal stem cells, and (2) differential responses to recognition of fetal APCs by maternal T cells.

Simvastatin-loaded liposome nanoparticles treatment for uterine leiomyoma in a patient-derived xenograft mouse model: a pilot study

Uterine leiomyomas are complex tumours with limited medical treatment options. Simvastatin is used to treat hypercholesterolaemia and has shown promising effects as a treatment option for leiomyomas. Previously, our group demonstrated a promising effect of simvastatin treatment in a patient-derived xenograft mouse model. Here, we tested the efficacy of simvastatin liposomal nanoparticles (NPs). After bilateral leiomyoma xenograft implantation, mice (N = 12) were divided into three treatment arms: control, simvastatin and simvastatin-loaded liposome NPs (simvastatin-NPs). Treatment with simvastatin significantly reduced tumour volume and inhibited the Ki67 expression when compared to the control group. There was a trend of reduced tumour volume and Ki67 expression after treatment with simvastatin-NP; however, the results were not significant. Due to low bioavailability and short half-life of simvastatin, liposomal NPs have the potential to enhance drug delivery, however, in this study NP did not provide improvement over simvastatin, but did demonstrate their potential for the delivery of simvastatin.Impact statementWhat is already known on this subject? Simvastatin treatment in a patient-derived xenograft mouse model reduced tumour growth and decreased proliferation.What do the results of this study add? Treatment with simvastatin significantly reduced tumour volume and inhibited the Ki67 expression when compared to the control group. There was a trend of reduced tumour volume and Ki67 expression after treatment with simvastatin-NP, however, it did not improve the efficacy of simvastatin at reducing tumour growth and proliferation.What are the implications of these findings for clinical practice and/or further research? More studies are needed to optimise the formulation of NPs to further enhance the sustainable delivery of simvastatin.

Lactic acid, citric acid and potassium bitartrate non-hormonal prescription vaginal pH modulator (VPM) gel for the prevention of pregnancy

INTRODUCTION

A non-hormonal prescription vaginal pH modulator (VPM) gel (Phexxi®), with active ingredients lactic acid, citric acid and potassium bitartrate, has recently been approved for prevention of pregnancy in the United States. The objective of this review is to compile the evidence available from published preclinical and clinical trials to support its use.

AREAS COVERED

PubMed was searched for published literature on VPM gel. Two Phase III trials were found on clinicaltrials.gov database. The results demonstrated that VPM gel is safe, with minimal side effects, and effective (cumulative 6-7 cycle pregnancy rate of 4.1-13.65%, (Pearl Index 27.5) as a contraceptive. Microbicidal effects suggest potential for the prevention of sexually transmitted infections (STIs); currently a Phase III clinical trial is being conducted to evaluate prevention of chlamydia and gonorrhea.

EXPERT OPINION

Non-hormonal reversible contraceptive options have been limited to the highly effective copper-releasing intrauterine device that requires insertion by a trained clinician, and less effective coitally-associated barrier and spermicide options which are typically available over-the-counter. Spermicides, which improve efficacy of barrier devices, may increase the risk of HIV/STIs. VPM gel provides a new safe, effective non-hormonal contraceptive option, with potential for prevention of STIs.

Inflammatory response elicited by Ureaplasma parvum colonization in human cervical epithelial, stromal, and immune cells

Ureaplasma parvum is a commensal bacterium in the female reproductive tract but has been associated with pregnancy complications such as preterm prelabor rupture of membranes and preterm birth (PTB). However, the pathologic effects of U. parvum in the cervix, which prevents ascending infections during pregnancy, are still poorly understood. To determine the impact of U. parvum on the cervix, ectocervical (ecto) and endocervical (endo) epithelial and stromal cells were incubated with U. parvum. Macrophages were also tested as a proxy for cervical macrophages to determine the antigenicity of U. parvum. The effects of U. parvum, including influence on cell cycle and cell death, antimicrobial peptide (AMP) production, epithelial-to-mesenchymal transition (EMT), and inflammatory cytokine levels, were assessed. U. parvum colonized cervical epithelial and stromal cells 4 h post-infection. Like uninfected control, U. parvum neither inhibited cell cycle progression and nor caused cell death in cervical epithelial and stromal cells. U. parvum increased the production of the AMPs cathelicidin and human β-defensin 3 and exhibited weak signs of EMT evidenced by decreased cytokeratin 18 and increased vimentin expression in cervical epithelial cells. U. parvum induced a proinflammatory environment (cytokines) and increased MMP-9 in cervical epithelial cells but promoted pro- and anti-inflammatory response in cervical stromal cells and macrophages. U. parvum may colonize the cervical epithelial layer, but induction of AMPs and anti-inflammatory response may protect the cervix and may prevent ascending infections that can cause PTB. These findings suggest that U. parvum is a weak inducer of inflammation in the cervix.

Characterization of the Ovine Vaginal Microbiome and Inflammation Patterns as an Improved Testing Model of Human Vaginal Irritation

The development of therapies targeted to improve the health of women has utilized direct vaginal delivery as a more effective and less toxic method of protection from HIV and other pathogens. Vaginal applicants and delivery devices that provide sustained effects have been met with increasing acceptability, but the efficacy and toxicity outcomes have not been successfully predicted by preclinical in vitro studies and animal modeling. We have explored the utilization of sheep as a model for testing the safety of vaginal applicants and devices based on spatial and structural similarities to the human vagina. As recently noted by the FDA, an additional safety measure is an impact on the vaginal microbiome (VMB) that is known to contribute to vaginal health and influence pathogen susceptibility and drug metabolism. To advance the utility of the sheep vaginal model, we completed a thorough molecular characterization of the ovine VMB utilizing both next-generation sequencing (NGS) and PCR methods. The process also created a custom PCR array to quantify ovine VMB community profiles in an affordable, higher throughput fashion. The results from vaginal swabs (>475 samples) collected from non-pregnant crossbred Dorset and Merino ewes treated with selected vaginal applicants or collected as sham samples established 16 VMB community types (VMB CTs). To associate VMB CTs with eubiosis or dysbiosis, we also completed custom ELISAs for six cytokines identifying IL1B, IL8, TNFa, and CXCL10 as useful markers to support the characterization of ovine vaginal inflammation. The results indicated that Pasteurella, Actinobacillus, Pseudomonas, Bacteroides, Leptotrichia, and E. coli were common markers of eubiosis (low inflammatory marker expression), and that Haemophilus, Ureaplasma, and Corynebacterium were associated with dysbiosis (high cytokine levels). Utilizing the optimized workflow, we also confirmed the utility of three commonly used vaginal applicants for impact on the VMB and inflammatory state, producing a dataset that supports the recommendation for the use of sheep for testing of vaginal applicants and devices as part of preclinical pipelines.

Development of Gram Stain Scoring System Based on Pro-Inflammatory Cytokines in the Sheep Model for Testing Toxicity of Vaginal Products

Background: Development of safe, effective products to prevent the sexual transmission of HIV remains a priority. Prior to clinical testing, the products must undergo strict safety evaluations to avoid mucosal drug toxicity, inflammation, and vaginal microbiome (VMB) shifts. Based on the Food and Drug Administration (FDA) guidance, we designed a study to measure the inflammatory markers and VMB changes after intravaginal treatment with products that have been associated with toxicity, with the objective to develop a Gram stain slide scoring system, similar to Nugent scoring, correlated with the proinflammatory cytokines in sheep.

Methods: Non-pregnant Dorset ewes (n = 34) were randomized to receive 5 ml intravaginal 4% nonoxynol-9 (N9) contraceptive gel, positive control (0.2% benzalkonium chloride), placebo control [hydroxethyl cellulose (HEC)], or no application daily for 10 days, with 11-day post-treatment follow-up. The vaginal swabs were collected for the cytokines, VMB, and Gram-stained slides. An enzyme-linked immunosorbent assay (ELISA) analysis of cytokines interleukin (IL)-1β, IL-8, CXCL10, and tumor necrosis factor-α (TNF-α) was used to determine inflammatory state of the sample. Vaginal microbiome community types (CT) were utilized to create five equivalent slide subsets for iterative development of a Gram-stained slide scoring system with comparisons with inflammatory state based on the cytokine levels.

Results: Digital images of the Gram-stained slides were scored based on Gram staining and morphology of bacteria, presence of sheep epithelial cells, and immune cells. The scoring system was modified in an iterative fashion with weighting based on cytokine categorization of inflamed samples, with three of four cytokine values above the mean indicating that the sample was inflamed. The parameters in the final version of the scoring system included mature epithelial cells, Gram-negative rods, and Gram-positive diplococci indicating normal and immune cells indicating inflammation. The area under the receiver operator characteristic curve (ROC AUC) was 0.725 (ROC AUCs range between 0.5 and 1.0) with a greater area indicating higher diagnostic ability of a test with a binary outcome: inflamed or normal.

Conclusion: The scoring system, derived from the advanced VMB and cytokine analyses, provides a validated, practical method for quantification of Gram-stained slides that can be performed in most laboratories, increasing the potential for standardization. The training plan can assist laboratories to determine the safety of intravaginal products in their sheep studies or the methodological approach can be applied to other animal models where such data are also needed.

The postcoital test in the development of new vaginal contraceptives†

Postcoital tests (PCTs) have been used for over a century in the clinical evaluation of infertile couples, and for nearly 70 years in the evaluation of new vaginal contraceptive products. PCTs have been largely replaced by more modern methods in the study of infertility, but they remain the most useful way to obtain preliminary data on the effectiveness of vaginal contraceptive products. The World Health Organization has described important aspects of the procedure. It involves collection of cervical mucus at a certain time point after intercourse and the counting and characterization of sperm found in the mucus. A wide range of progressively motile sperm (PMS) has been associated with pregnancy rates in infertility studies. Eligibility for contraceptive trials includes the requirement that couples achieve a certain threshold number of PMS per high power field at midcycle in a baseline cycle without the test product. The primary endpoint, or definition of a satisfactory result in test cycles, is predefined. A literature review identified 10 PCT studies of vaginal contraceptives involving nine test products. Phase II trials of vaginal contraceptives have not been deemed feasible in the development of any vaginal contraceptive to date. A PCT study of a test product can be predictive of contraceptive efficacy, although ultimate contraceptive effectiveness is influenced by the ease of use of the product, along with patient compliance. PCT results similar to results seen with products that later showed satisfactory performance in efficacy trials is the best indicator of likely success of a test product.

High-Resolution Quantitative Mapping of Macaque Cervicovaginal Epithelial Thickness: Implications for Mucosal Vaccine Delivery

Vaginal mucosal surfaces naturally offer some protection against sexually transmitted infections (STIs) including Human Immunodeficiency Virus-1, however topical preventative medications or vaccine designed to boost local immune responses can further enhance this protection. We previously developed a novel mucosal vaccine strategy using viral vectors integrated into mouse dermal epithelium to induce virus-specific humoral and cellular immune responses at the site of exposure. Since vaccine integration occurs at the site of cell replication (basal layer 100-400 micrometers below the surface), temporal epithelial thinning during vaccine application, confirmed with high resolution imaging, is desirable. In this study, strategies for vaginal mucosal thinning were evaluated noninvasively using optical coherence tomography (OCT) to map reproductive tract epithelial thickness (ET) in macaques to optimize basal layer access in preparation for future effective intravaginal mucosal vaccination studies. Twelve adolescent female rhesus macaques (5-7kg) were randomly assigned to interventions to induce vaginal mucosal thinning, including cytobrush mechanical abrasion, the chemical surfactant spermicide nonoxynol-9 (N9), the hormonal contraceptive depomedroxyprogesterone acetate (DMPA), or no intervention. Macaques were evaluated at baseline and after interventions using colposcopy, vaginal biopsies, and OCT imaging, which allowed for real-time in vivo visualization and measurement of ET of the mid-vagina, fornices, and cervix. P value ≤0.05 was considered significant. Colposcopy findings included pink, rugated tissue with variable degrees of white-tipped, thickened epithelium. Baseline ET of the fornices was thinner than the cervix and vagina (p<0.05), and mensing macaques had thinner ET at all sites (p<0.001). ET was decreased 1 month after DMPA (p<0.05) in all sites, immediately after mechanical abrasion (p<0.05) in the fornix and cervix, and after two doses of 4% N9 (1.25ml) applied over 14 hrs in the fornix only (p<0.001). Histological assessment of biopsied samples confirmed OCT findings. In summary, OCT imaging allowed for real time assessment of macaque vaginal ET. While varying degrees of thinning were observed after the interventions, limitations with each were noted. ET decreased naturally during menses, which may provide an ideal opportunity for accessing the targeted vaginal mucosal basal layers to achieve the optimum epithelial thickness for intravaginal mucosal vaccination.

Liposomal 2-Methoxyestradiol Nanoparticles for Treatment of Uterine Leiomyoma in a Patient-Derived Xenograft Mouse Model

Uterine leiomyomas represent a challenging problem with limited medical treatment options. The anti-tumor agent 2-methoxyestradiol (2-ME) shows promising results but its efficacy is limited by inadequate pharmacokinetics. We previously demonstrated that 2-ME nanoparticles can be successfully formulated and that they show improved in vitro anti-leiomyoma cell activity. Here, we examined the effects of the in vivo delivery of 2-ME nanoparticles in a patient-derived xenograft (PDX) leiomyoma mouse model. Patient-derived leiomyoma tumor tissues were xenografted subcutaneously in estrogen/progesterone pretreated immunodeficient NOG mice. Animals (n = 12) were treated with liposomal 2-ME nanoparticles by intra-peritoneal (IP) injection (50 mg/kg/dose, three times weekly) or control for 28 days. Tumor volume was measured weekly by calipers and prior to sacrifice by ultrasound. In addition, the expression of the cell proliferation marker Ki67 and the apoptosis marker cleaved caspase-3 in tumor tissues after treatment were measured by immunohistochemistry. Liposomal 2-ME treatment was associated with a significant tumor growth inhibition (30.5% less than controls as early as 2 weeks, p = 0.025). In addition, injections of liposomal 2-ME inhibited the expression of the proliferation marker Ki67 (55.8% reduction, p < 0.001). Furthermore, liposomal 2-ME treatment was associated with a 67.5% increase of cleaved caspase-3 expression of increase (p = 0.048). Our findings suggest that liposomal nanoparticle formulation can successfully deliver 2-ME and can be a promising therapeutic strategy for uterine leiomyoma. Further characterization of the liposomal-2ME, including pharmacokinetics, maximal tolerated dose, and safety, is needed in preclinical models prior to clinical trials.

Surrogate post-coital testing for contraceptive efficacy against human sperm activity in the ovine vaginal model†

High unintended pregnancy rates are partially due to lack of effective nonhormonal contraceptives; development of safe, effective topical vaginal methods will address this need. Preclinical product safety and efficacy assessment requires in vivo testing in appropriate models. The sheep is a good model for the evaluation of vaginally delivered products due to its close similarities to humans. The study objective was to develop an ovine model for efficacy testing of female nonhormonal contraceptives that target human sperm. Fresh human semen was pooled from male volunteers. Nonpregnant female Merino sheep were treated with control or vaginal contraceptive product (IgG antibody with action against sperm or nonoxynol-9 [N9]). Pooled semen was added to the sheep vagina and mixed with product and vaginal secretions. Microscopic assessment of samples was performed immediately and progressive motility (PM) of sperm was compared between treatments. Cytokines CXCL8 and IL1B were assessed in vaginal fluid after instillation of human semen. No adverse reactions or elevations in proinflammatory cytokines occurred in response to human semen. N9 produced signs of acute cellular toxicity while there were no cellular changes after IgG treatment. N9 and IgG had dose-related effects with the highest dose achieving complete sperm immobilization (no sperm with PM). Surrogate post-coital testing of vaginally administered contraceptives that target human semen was developed in an ovine model established for vaginal product preclinical testing. This expanded model can aid the development of much needed nonhormonal topical vaginal contraceptives, providing opportunities for rapid iterative drug development prior to costly, time-intensive human testing.

Multispecies Evaluation of a Long-Acting Tenofovir Alafenamide Subdermal Implant for HIV Prophylaxis

New HIV-1 infection rates far outpace the targets set by global health organizations, despite important progress in curbing the progression of the epidemic. Long-acting (LA) formulations delivering antiretroviral (ARV) agents for HIV-1 pre-exposure prophylaxis (PrEP) hold significant promise, potentially facilitating adherence due to reduced dosing frequency compared to oral regimens. We have developed a subdermal implant delivering the potent ARV drug tenofovir alafenamide that could provide protection from HIV-1 infection for 6 months, or longer. Implants from the same lot were investigated in mice and sheep for local safety and pharmacokinetics (PKs). Ours is the first report using these animal models to evaluate subdermal implants for HIV-1 PrEP. The devices appeared safe, and the plasma PKs as well as the drug and metabolite concentrations in dermal tissue adjacent to the implants were studied and contrasted in two models spanning the extremes of the body weight spectrum. Drug and drug metabolite concentrations in dermal tissue are key in assessing local exposure and any toxicity related to the active agent. Based on our analysis, both animal models were shown to hold significant promise in LA product development.

Long-Term Effect of Lactation on Maternal Cardiovascular Function and Adiposity in a Murine Model

OBJECTIVE

Epidemiological studies suggest that lactation is associated with long-term maternal health benefits. To avoid confounders in human studies, we used a previously characterized murine model to investigate the long-term effect of lactation on both cardiovascular function and adiposity.

STUDY DESIGN

After the delivery of the pups, CD-1 female mice were randomly divided into two groups: lactated and nonlactated (NL). Before pregnancy and at 9 months postdelivery, blood pressure was measured using a tail cuff, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were assessed by computed tomography (CT), echocardiography was performed using microultrasound, and cholesterol panels and fasting blood glucose were measured. The data were analyzed using Student's t-test (significance at p < 0.05).

RESULTS

There were no differences in baseline parameters between the two groups. At 9 months postdelivery, the NL group weighed significantly more (p = 0.03) and demonstrated a significantly lower cardiac output (p = 0.05) and ejection fraction (p = 0.03). The mice in the NL group also had higher VAT (p < 0.01) and SAT percentiles (p = 0.03). Fasting glucose (p = 0.01) and low-density lipoprotein (p = 0.01) were significantly higher in the NL group at 9 months.

CONCLUSION

Our results show the benefit of lactation is not just limited to the immediate postpartum period but it also extends into midlife in a murine model.

Cultivated Human Vaginal Microbiome Communities Impact Zika and Herpes Simplex Virus Replication in ex vivo Vaginal Mucosal Cultures

The human vaginal microbiome (VMB) is a complex bacterial community that interacts closely with vaginal epithelial cells (VECs) impacting the mucosal phenotype and its responses to pathogenic insults. The VMB and VEC relationship includes nutrient exchange and regulation of signaling molecules that controls numerous host functions and defends against invading pathogens. To better understand infection and replication of sexually transmitted viral pathogens in the human vaginal mucosa we used our ex vivo VEC multilayer culture system. We tested the hypothesis that selected VMB communities could be identified that alter the replication of sexually transmitted viruses consistent with reported clinical associations. Sterile VEC multilayer cultures or those colonized with VMB dominated by specific Lactobacillus spp., or VMB lacking lactobacilli, were infected with Zika virus, (ZIKV) a single stranded RNA virus, or Herpes Simplex Virus type 2 (HSV-2), a double stranded DNA virus. The virus was added to the apical surface of the cultured VEC multilayer to model transmission during vaginal intercourse. Viral replication was measured 48 h later by qPCR. The results indicated that VEC cultures colonized by VMB containing Staphylococcus spp., previously reported as inflammatory, significantly reduced the quantity of viral genomes produced by ZIKV. HSV-2 titers were decreased by nearly every VMB tested relative to the sterile control, although Lactobacillus spp.-dominated VMBs caused the greatest reduction in HSV-2 titer consistent with clinical observations. To explore the mechanism for reduced ZIKV titers, we investigated inflammation created by ZIKV infection, VMB colonization or pre-exposure to selected TLR agonists. Finally, expression levels of human beta defensins 1–3 were quantified in cultures infected by ZIKV and those colonized by VMBs that impacted ZIKV titers. Human beta defensins 1–3 produced by the VEC showed no association with ZIKV titers. The data presented expands the utility of this ex vivo model system providing controlled and reproducible methods to study the VMB impact on STIs and indicated an association between viral replication and specific bacterial species within the VMB.

Safety and pharmacokinetics of single, dual, and triple antiretroviral drug formulations delivered by pod-intravaginal rings designed for HIV-1 prevention: A Phase I trial

BACKGROUND

Intravaginal rings (IVRs) for HIV pre-exposure prophylaxis (PrEP) theoretically overcome some adherence concerns associated with frequent dosing that can occur with oral or vaginal film/gel regimens. An innovative pod-IVR, composed of an elastomer scaffold that can hold up to 10 polymer-coated drug cores (or "pods"), is distinct from other IVR designs as drug release from each pod can be controlled independently. A pod-IVR has been developed for the delivery of tenofovir (TFV) disoproxil fumarate (TDF) in combination with emtricitabine (FTC), as daily oral TDF-FTC is the only Food and Drug Administration (FDA)-approved regimen for HIV PrEP. A triple combination IVR building on this platform and delivering TDF-FTC along with the antiretroviral (ARV) agent maraviroc (MVC) also is under development.

METHODOLOGY AND FINDINGS

This pilot Phase I trial conducted between June 23, 2015, and July 15, 2016, evaluated the safety, pharmacokinetics (PKs), and acceptability of pod-IVRs delivering 3 different ARV regimens: 1) TDF only, 2) TDF-FTC, and 3) TDF-FTC-MVC over 7 d. The crossover, open-label portion of the trial (N = 6) consisted of 7 d of continuous TDF pod-IVR use, a wash-out phase, and 7 d of continuous TDF-FTC pod-IVR use. After a 3-mo pause to evaluate safety and PK of the TDF and TDF-FTC pod-IVRs, TDF-FTC-MVC pod-IVRs (N = 6) were evaluated over 7 d of continuous use. Safety was assessed by adverse events (AEs), colposcopy, and culture-independent analysis of the vaginal microbiome (VMB). Drug and drug metabolite concentrations in plasma, cervicovaginal fluids (CVFs), cervicovaginal lavages (CVLs), and vaginal tissue (VT) biopsies were determined via liquid chromatographic-tandem mass spectrometry (LC-MS/MS). Perceptibility and acceptability were assessed by surveys and interviews. Median participant age was as follows: TDF/TDF-FTC group, 26 y (range 24-35 y), 2 White, 2 Hispanic, and 2 African American; TDF-FTC-MVC group, 24.5 y (range 21-41 y), 3 White, 1 Hispanic, and 2 African American. Reported acceptability was high for all 3 products, and pod-IVR use was confirmed by residual drug levels in used IVRs. There were no serious adverse events (SAEs) during the study. There were 26 AEs reported during TDF/TDF-FTC IVR use (itching, discharge, discomfort), with no differences between TDF alone or in combination with FTC observed. In the TDF-FTC-MVC IVR group, there were 12 AEs (itching, discharge, discomfort) during IVR use regardless of attribution to study product. No epithelial disruption/thinning was seen by colposcopy, and no systematic VMB shifts were observed. Median (IQR) tenofovir diphosphate (TFV-DP) tissue concentrations of 303 (277-938) fmol/10(6) cells (TDF), 289 (110-603) fmol/10(6) cells (TDF-FTC), and 302 (177.1-823.8) fmol/10(6) cells (TDF-FTC-MVC) were sustained for 7 d, exceeding theoretical target concentrations for vaginal HIV prevention. The study's main limitations include the small sample size, short duration (7 d versus 28 d), and the lack of FTC triphosphate measurements in VT biopsies.

CONCLUSIONS

An innovative pod-IVR delivery device with 3 different formulations delivering different regimens of ARV drugs vaginally appeared to be safe and acceptable and provided drug concentrations in CVFs and tissues exceeding concentrations achieved by highly protective oral dosing, suggesting that efficacy for vaginal HIV PrEP is achievable. These results show that an alternate, more adherence-independent, longer-acting prevention device based on the only FDA-approved PrEP combination regimen can be advanced to safety and efficacy testing.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02431273.

User evaluations offer promise for pod-intravaginal ring as a drug delivery platform: A mixed methods study of acceptability and use experiences

BACKGROUND

Effective HIV prevention requires efficient delivery of safe and efficacious drugs and optimization of user adherence. The user's experiences with the drug, delivery system, and use parameters are critical to product acceptability and adherence. Prevention product developers have the opportunity to directly control a drug delivery system and its impact on acceptability and adherence, as well as product efficacy. Involvement of potential users during preclinical design and development can facilitate this process. We embedded a mixed methods user evaluation study into a safety and pharmacokinetics (PK) trial of a pod-intravaginal ring delivering antiretroviral agents.

METHODOLOGY

Women enrolled in two cohorts, ultimately evaluating the safety/PK of a pod-IVRs delivering TDF-alone, TDF-FTC, and/or TDF-FTC-MVC. A 7-day use period was targeted for each pod-IVR, regardless of drug or drug combination. During the clinical study, participants provided both quantitative (i.e., survey) and qualitative (i.e., in-depth interview) data capturing acceptability, perceptibility, and adherence behaviors. Initial sexual and reproductive health history surveys, daily diaries, a final acceptability and willingness to use survey, and a qualitative in-depth interview comprised the user evaluation data for each pod-IVR experienced by the participants.

FINDINGS

Overall, the majority of participants (N = 10) reported being willing to use the pod-IVR platform for HIV prevention should it advance to market. Confidence to use the pod-IVR (e.g., insertion, removal) was high. There were no differences noted in the user experience of the pod-IVR platform; that is, whether the ring delivered TDF-alone, TDF-FTC, or TDF-FTC-MVC, users' experiences of the ring were similar and acceptable. Participants did report specific experiences, both sensory and behavioral, that impacted their use behaviors with respect to the ring, and which could ultimately impact acceptability and adherence. These experiences, and user evaluations elicited by them, could both challenge use or be used to leverage use in future trials and product rollout once fully articulated.

CONCLUSIONS

High willingness-to-use data and lack of salient differences in user experiences related to use of the pod-IVR platform (regardless of agents delivered) suggests that the pod-IVR is a feasible and acceptable drug delivery device in and of itself. This finding holds promise both for an anti-HIV pod-IVR and, potentially, a multipurpose prevention pod-IVR that could deliver both prevention for sexually transmitted infections (STIs) including HIV and contraception. Given the very early clinical trial context, further acceptability, perceptibility, and adherence data should continue to be explored, in the context of longer use periods (e.g., 28-day ring use), and in the contexts of sexual activity and menses. Using early design and development contexts to gain insights into potential challenges and facilitators of drug delivery systems such as the pod-IVR could save valuable resources and time as a potential biomedical technology moves through the clinical trial pipeline and into real-world use.

Evaluation of immunological markers of ovine vaginal irritation: Implications for preclinical assessment of non-vaccine HIV preventive agents

The presence of genital inflammatory responses and a compromised vaginal epithelial barrier have been linked to an increased risk of HIV acquisition. It is important to assure that application of candidate microbicides designed to limit HIV transmission will not cause these adverse events. We previously developed high resolution in vivo imaging methodologies in sheep to assess epithelial integrity following vaginal application of a model microbicide, however characterization of genital inflammation in sheep has not been previously possible. In this study, we significantly advanced the sheep model by developing approaches to detect and quantify inflammatory responses resulting from application of a nonoxynol-9-containing gel known to elicit vaginal irritation. Vaginal application of this model microbicide resulted in foci of disrupted epithelium detectable by confocal endomicroscopy. Leukocytes also infiltrated the treated mucosa and the number and composition of leukocytes obtained by cervicovaginal lavage (CVL) were determined by differential staining and flow cytometry. By 18h post-treatment, a population comprised predominantly of granulocytes and monocytes infiltrated the vagina and persisted through 44h post-treatment. The concentration of proinflammatory cytokines and chemokines in CVL was determined by quantitative ELISA. Concentrations of IL-8 and IL-1β were consistently significantly increased after microbicide application suggesting these cytokines are useful biomarkers for epithelial injury in the sheep model. Together, the results of these immunological assessments mirror those obtained in previous animal models and human trials with the same compound and greatly extend the utility of the sheep vaginal model in assessing the vaginal barrier and immune microenvironment.

Vaginal ecosystem modeling of growth patterns of anaerobic bacteria in microaerophilic conditions

The human vagina constitutes a complex ecosystem created through relationships established between host mucosa and bacterial communities. In this ecosystem, classically defined bacterial aerobes and anaerobes thrive as communities in the microaerophilic environment. Levels of CO₂ and O₂ present in the vaginal lumen are impacted by both the ecosystem's physiology and the behavior and health of the human host. Study of such complex relationships requires controlled and reproducible causational approaches that are not possible in the human host that, until recently, was the only place these bacterial communities thrived. To address this need we have utilized our ex vivo human vaginal mucosa culture system to support controlled, reproducible colonization by vaginal bacterial communities (VBC) collected from healthy, asymptomatic donors. Parallel vaginal epithelial cells (VEC)-VBC co-cultures were exposed to two different atmospheric conditions to study the impact of CO₂ concentrations upon the anaerobic bacteria associated with dysbiosis and inflammation. Our data suggest that in the context of transplanted VBC, increased CO₂ favored specific lactobacilli species defined as microaerophiles when grown as monocultures. In preliminary studies, the observed community changes also led to shifts in host VEC phenotypes with significant changes in the host transcriptome, including altered expression of select molecular transporter genes. These findings support the need for additional study of the environmental changes associated with behavior and health upon the symbiotic and adversarial relationships that are formed in microbial communities present in the human vaginal ecosystem.

Elevated Testosterone Reduces Uterine Blood Flow, Spiral Artery Elongation, and Placental Oxygenation in Pregnant Rats

Elevated maternal testosterone levels are shown to cause fetal growth restriction, eventually culminating in sex-specific adult-onset hypertension that is more pronounced in males than in females. In this study, we tested whether uteroplacental and fetoplacental disturbances underlie fetal growth restriction and if these changes vary in male and female placentas. Pregnant Sprague-Dawley rats were injected with vehicle (n=16) or testosterone propionate (0.5 mg/kg per day from gestation day 15-19; n=16). On gestation day 20, we quantified uterine artery blood flow using microultrasound, visualized placental arterial network using x-ray microcomputed tomography, determined fetoplacental hypoxia using pimonidazole and hypoxia-inducible factor-1α, and used Affymetrix array to determine changes in placental expression of genes involved in vascular development. Plasma testosterone levels increased 2-fold in testosterone-injected rats. Placental and fetal weights were lower in rats with elevated testosterone. Uterine artery blood flow was lower, and resistance index was higher in the testosterone group. Radial and spiral artery diameter and length, the number of fetoplacental arterial branches, and umbilical artery diameter were reduced in the testosterone group. In addition, markers of hypoxia in the placentas and fetuses were elevated in the testosterone group. The magnitude of changes in placental vasculature and hypoxia was greater in males than in females and was associated with sex-specific alteration of unique sets of genes involved in angiogenesis and blood vessel morphogenesis. The results demonstrate that elevated testosterone during gestation induces a decrease in uterine arterial blood flow and fetal sex-related uteroplacental vascular changes, which may set the stage for subsequent sex differences in adult-onset diseases.

Effect of lactation on maternal postpartum cardiac function and adiposity: a murine model

OBJECTIVE

Lactation is associated with reduction in maternal metabolic disease and hypertension later in life; however, findings in humans may be confounded by socioeconomic factors. We sought to determine the independent contribution of lactation on cardiovascular parameters and adiposity in a murine model.

STUDY DESIGN

Following delivery, CD-1 female mice were randomly divided into 2 groups: lactated (L; nursed pups for 3 weeks, n = 10), and nonlactated (NL; pups were removed after birth, n = 12). Blood pressure (BP) was assessed prepregnancy and at 1 and 2 months' postpartum. Visceral and subcutaneous adipose tissue determined by computed tomography and left ventricular ejection fraction, cardiac output, and the E/A ratio determined by microultrasound were evaluated at 1 and 2 months' postpartum. The results were analyzed using a Student t test (significance at P < .05).

RESULTS

We observed a significantly different maternal BP at 2 months' postpartum with relatively greater BP in NL (systolic BP: NL, 122.2 ± 7.2 vs L, 96.8 ± 9.8 mm Hg; P = .04; diastolic BP: NL, 87.0 ± 6.8 vs L, 65.9 ± 6.2 mm Hg; P = .04). Visceral adipose tissue was significantly increased in NL mice at 1 (22.0 ± 4.1% vs 10.7 ± 1.8%, P = .04) and 2 months' postpartum (22.9 ± 3.5% vs 11.2 ± 2.2%, P = .02), whereas subcutaneous adipose tissue did not differ between the groups. At 2 months' postpartum, ejection fraction (51.8 ± 1.5% vs 60.5 ± 3.8%; P = .04), cardiac output (14.2 ± 1.0 vs 18.0 ± 1.3 mL/min; P = .02) and mitral valve E/A ratio (1.38 ± 0.06 vs 1.82 ± 0.13; P = .04) were significantly lower in NL mice than L mice.

CONCLUSION

Our data provide evidence that interruption of lactation adversely affects postpartum maternal cardiovascular function and adiposity.

Elevated testosterone levels during rat pregnancy cause hypersensitivity to angiotensin II and attenuation of endothelium-dependent vasodilation in uterine arteries

Elevated testosterone levels increase maternal blood pressure and decrease uterine blood flow in pregnancy, resulting in abnormal perinatal outcomes. We tested whether elevated testosterone alters uterine artery adaptations during pregnancy, and whether these alterations depend on endothelium-derived factors such as nitric oxide, endothelium-derived hyperpolarizing factor, and prostacyclin, or endothelium-independent mechanisms such as angiotensin II (Ang-II). Pregnant Sprague-Dawley rats were injected with vehicle (n=20) or testosterone propionate (0.5 mg/kg per day from gestation day 15 to 19; n=20). Plasma testosterone levels increased 2-fold in testosterone-injected rats compared with controls. Elevated testosterone significantly decreased placental and pup weights compared with controls. In endothelium-intact uterine arteries, contractile responses to thromboxane, phenylephrine, and Ang-II were greater in testosterone-treated rats compared with controls. In endothelium-denuded arteries, contractile responses to Ang-II (pD2=9.1±0.04 versus 8.7±0.04 in controls; P<0.05), but not thromboxane and phenylephrine, were greater in testosterone-treated rats. Ang-II type 1b receptor expression was increased, whereas Ang-II type 2 receptor was decreased in testosterone-exposed arteries. In endothelium-denuded arteries, relaxations to sodium nitroprusside were unaffected. Endothelium-dependent relaxation to acetylcholine was significantly lower in arteries from testosterone-treated dams (Emax=51.80±6.9% versus 91.98±1.4% in controls; P<0.05). The assessment of endothelial factors showed that nitric oxide-, endothelium-derived hyperpolarizing factor-, and prostacyclin-mediated relaxations were blunted in testosterone-treated dams. Endothelial nitric oxide synthase, small conductance calcium-activated potassium channel-3, and prostacyclin receptor expressions were significantly decreased in arteries from testosterone-treated dams. Hypoxia-inducible factor-1α, Ankrd37, and Egln were significantly increased in testosterone-exposed placentas. These results suggest that elevated maternal testosterone impairs uterine vascular function, which may lead to an increased vascular resistance and a decrease in uterine blood flow.

Global expression of molecular transporters in the human vaginal tract: implications for HIV chemoprophylaxis

Background

Pre-exposure chemoprophylaxis (PrECP) using antiretroviral agents is a promising strategy for the prevention of sexual HIV transmission in women. Molecular transporters in the human vaginal tract (VT) may play a pivotal role in determining drug disposition and, consequently, pharmacodynamic outcomes in these efforts. Little is known, however, on the expression of these transporters in vaginal tissues, representing a critical knowledge gap.

Methodology/Principal Findings

Our study analyzed the genome-wide transcriptome in 44 vaginal tissue samples from 6 reproductive-age women undergoing gynecologic surgeries. The analysis revealed that, unexpectedly, a large number (43%) of gene isoforms corresponding to membrane transporters were over-expressed (above the median expression level) in all samples. A subset of 12 highly expressed membrane transporters was identified and contained 10 members (83%) of the solute carrier superfamily. The largest difference in membrane transporter gene expression was observed across subjects, but more subtle differential expression also was found along the anterior-posterior axis of the VT. Cross-validation of the microarray analyses with measurements RT-qPCR demonstrated high concordance between these data sets. Immunofluorescence labeling of membrane transporter proteins in vaginal tissues was highly dependent on tissue/cell types.

Conclusions/Significance

Antiretroviral PrECP drugs currently under evaluation are substrates for molecular transporters that were commonly expressed, but fell into both over- or under-expressed categories in all samples, suggesting a complex role for carrier-mediated processes in determining the disposition of these xenobiotics in vaginal tissues. These findings hold important implications for the successful development of products, either oral or intravaginal, for female-controlled HIV PrECP.

Pharmacokinetics of a multipurpose pod-intravaginal ring simultaneously delivering five drugs in an ovine model

Multipurpose technologies that simultaneously protect from sexually transmitted infections and unintended pregnancy are urgently needed. Pod-intravaginal rings (IVRs) formulated with the antiretroviral agents (ARVs) tenofovir, nevirapine, and saquinavir and the contraceptives etonogestrel and estradiol were evaluated in sheep. Steady-state concentrations were maintained for 28 days with controlled, sustained delivery. This proof-of-principle study demonstrates that pod IVRs can deliver three ARVs from different mechanistic classes and a progestin-estrogen combination over the wide range needed for putative preventative efficacy.

Optical coherence tomography for assessment of microbicide safety in a small animal model

Sensitive imaging techniques for small animals are needed to assess drug toxicity in preclinical studies. Optical coherence tomography (OCT) provides a noninvasive tool for high-resolution, depth-resolved visualization of drug-induced changes in tissue morphology. In a mouse model, we utilize OCT to assess vaginal tissue integrity following the application of topical microbicides (drugs used to prevent infection). Mice are challenged with herpes simplex virus-2 (HSV-2) to determine the correlation of tissue damage as quantified by OCT to increased susceptibility. The microbicide benzalkonium chloride (BZK) (0.02, 0.2, or 2%) or phosphate buffered saline control is administered intravaginally. In vivo OCT imaging and collection of tissue samples are performed after treatment. A quantitative OCT scoring system is applied to assess epithelial damage, and the results are compared with those of histology. A separate group of mice are treated similarly then challenged with HSV-2. Epithelial morphology quantified noninvasively by OCT and histology are dose-dependent (p<0.0001). The OCT scoring system detected a significant increase in epithelial damage with increasing BZK concentration (p<0.0001). These results paralleled an increase in HSV-2 susceptibility (p<0.005). OCT can be used as a noninvasive tool to assess topical drug toxicity in a small animal model with potential to predict increased susceptibility to vaginal infection.

Monitoring vaginal epithelial thickness changes noninvasively in sheep using optical coherence tomography

OBJECTIVE

High-resolution optical coherence tomography can be used noninvasively to evaluate vaginal morphologic features, including epithelial thickness, to assess this protective barrier in transmission of sexually transmitted infections and to monitor tissue response to topical medications and hormonal fluctuations. We examined the use of optical coherence tomography to measure epithelial thickness noninvasively before and after topical treatment with a drug that causes epithelial thinning.

STUDY DESIGN

Twelve female sheep were treated with intravaginal placebo (n = 4) or nonoxynol-9 (n = 8). Vaginal optical coherence tomography images were obtained before and 24 hours after treatment. Four sheep in the nonoxynol-9 group were also examined on days 3 and 7. Vaginal biopsies were obtained on the last examination day. Epithelial thickness was measured in optical coherence tomography images and in hematoxylin and eosin-stained histologic sections from biopsies. Statistical analysis was performed using analyses of variance (significance P < .05).

RESULTS

Baseline optical coherence tomography epithelial thickness measurements were similar (85 ± 19 μm placebo, 78 ± 20 μm nonoxynol-9; P = .52). Epithelial thinning was significant after nonoxynol-9 (32 ± 22 μm) compared with placebo (80 ± 15 μm) 24 hours after treatment (P < .0001). In the 4 nonoxynol-9-treated sheep followed for 7 days, epithelial thickness returned to baseline by day 3, and increased significantly on day 7. Epithelial thickness measurements from histology were not significantly different than optical coherence tomography (P = .98 nonoxynol-9, P = .93 hydroxyethyl cellulose).

CONCLUSION

Drug-induced changes in the epithelium were clearly detectable using optical coherence tomography imaging. Optical coherence tomography and histology epithelial thickness measurements were similar, validating optical coherence tomography as a noninvasive method for epithelial thickness measurement, providing an important tool for quantitative and longitudinal monitoring of vaginal epithelial changes.

Automated segmentation algorithm for detection of changes in vaginal epithelial morphology using optical coherence tomography

We have explored the use of optical coherence tomography (OCT) as a noninvasive tool for assessing the toxicity of topical microbicides, products used to prevent HIV, by monitoring the integrity of the vaginal epithelium. A novel feature-based segmentation algorithm using a nearest-neighbor classifier was developed to monitor changes in the morphology of vaginal epithelium. The two-step automated algorithm yielded OCT images with a clearly defined epithelial layer, enabling differentiation of normal and damaged tissue. The algorithm was robust in that it was able to discriminate the epithelial layer from underlying stroma as well as residual microbicide product on the surface. This segmentation technique for OCT images has the potential to be readily adaptable to the clinical setting for noninvasively defining the boundaries of the epithelium, enabling quantifiable assessment of microbicide-induced damage in vaginal tissue.

Optical coherence tomography compared with colposcopy for assessment of vaginal epithelial damage: a randomized controlled trial

OBJECTIVE

Colposcopy has been used to detect epithelial damage with vaginal microbicides. In animal models, optical coherence tomography provided increased sensitivity over colposcopy in detecting epithelial injury. This randomized, double-blinded, clinical study compared optical coherence tomography to colposcopy for the evaluation of epithelial injury in women using placebo or nonoxynol-9.

METHODS

Thirty women aged 18-45 were randomized to use hydroxyethyl cellulose placebo or nonoxynol-9 vaginal gel twice daily for 5.5 days. Imaging with colposcopy and optical coherence tomography was performed before product use, after the last dose, and 1 week later. Colposcopy was graded using standard criteria. Optical coherence tomography images were scored for epithelial integrity based on a published scoring system and were measured for epithelial thickness.

RESULTS

Colposcopy findings, optical coherence tomography scores, and epithelial thicknesses were similar between treatment groups at baseline. After treatment, there were significant differences between the nonoxynol-9 (1.37) and control group (1.15) optical coherence tomography scores (P<.001), indicating epithelial injury, and there was epithelial thinning in the nonoxynol-9 group (237 micrometers) compared with the control group (292 micrometers; P=.008). There were no significant posttreatment colposcopic differences in epithelial disruption between treatment groups, with only increased erythema noted after nonoxynol-9 use (P=.02).

CONCLUSION

Optical coherence tomography detected epithelial disruption and thinning not identified by colposcopy. Vaginal epithelial thickness, a measure previously available only through biopsy, decreased after nonoxynol-9 use, a finding that may contribute to increased susceptibility to human immunodeficiency virus after frequent use. Optical coherence tomography shows promise for the noninvasive clinical assessment of vaginal epithelial damage.

CLINICAL TRIAL REGISTRATION

UMIN Clinical Trials Registry, www.umin.ac.jp/ctr/index.htm, R000006186.

LEVEL OF EVIDENCE

I.