Vaginal Lubricants Research Articles

Response to Letter to the Editor on "A randomized trial on the effectiveness and safety of 5 water-based personal lubricants".

Response to Letter to the Editor on "A randomized trial on the effectiveness and safety of 5 water-based personal lubricants".

Modern approach to the management of genitourinary syndrome in women with gynecological malignancies.

The term genitourinary syndrome of menopause was first used in 2014 by the North American Menopause Society and the International Society for the Study of Women's Sexual Health to describe conditions previously known as atrophic vaginitis, urogenital atrophy, or vulvovaginal atrophy. It is a complex, chronic, progressive condition characterized by a wide range of signs and symptoms affecting sexual function and the tissues of the urinary and genital tracts. The main cause of genitourinary syndrome of menopause is estrogen deficiency caused by ovarian removal or dysfunction. The most bothersome symptoms are vaginal dryness, decreased vaginal lubrication, and pain during penetration and intercourse. They all have a negative impact on the quality of life. The main goal of treatment is to relieve the symptoms. Treatment modalities are pharmacological or non-pharmacological. The first-line treatment for mild to moderate symptoms is the use of personal lubricants and moisturizers, but the gold standard is estrogen replacement therapy. Hormone therapy may not be an option for women with hormone-dependent cancer.

A potent non-hormonal option for the treatment of postmenopausal vaginal dryness with high tolerability

Genitourinary syndrome of menopause (GSM) is considered a chronic condition with urogenital implications caused by estrogen deficiency typically after onset of menopause. Vaginal dryness accompanied by burning and itching is one of the most prevalent and bothersome symptoms of GSM. Affected women suffer from reduced lubrication and, those who are sexually active, also from dyspareunia. Non-hormonal therapies, such as vaginal moisturizers or lubricants, are recommended as first-line treatments to achieve the relief of symptoms, while improving the quality of life. Due to emerging demand for pessary formulations, we evaluated the efficacy and tolerability of a non-hormonal pessary containing nourishing lipids and lactic acid. Therefore, a prospective, open-label clinical trial was performed, including 79 postmenopausal women with symptoms of vaginal dryness. The patients applied one pessary daily within the first week followed by two pessaries per week for the next 31 days. After 38 days of treatment, a treatment free period of 6 days completed the trial. Subjective symptoms of vaginal dryness, such as feeling of dryness, itching, burning and pain (unrelated and related to sexual intercourse), were assessed at every visit, while the objective vaginal health index (VHI) was only examined at beginning and end of treatment. Data regarding the impact on patients’ quality of life, efficacy and tolerability were evaluated using various questionnaires. Our data show that symptoms of vulvovaginal dryness, itching, burning and pain as well as dyspareunia significantly decreased from baseline to end of treatment (day 38) and beyond. Quality of life assessed by DIVA (day-to day impact of vaginal aging) questionnaire, and VHI also clearly improved over the study period. The tolerability was rated as 'good' or 'very good' by most of the patients and by the investigator. No serious adverse events and only a low number of mild adverse events rated as related to the vaginal pessary were reported. Overall, this study identifies the investigated non-hormonal pessary as a potent option for the treatment of postmenopausal symptoms of vaginal dryness with a high tolerability. It can therefore be recommended as a first-line treatment that contributes to maintaining a healthy vaginal environment in postmenopausal women.

Investigating the impact of condomless vaginal intercourse and lubricant use on the vaginal metabolome: a pre-post observational study

ObjectiveThe vaginal metabolome is a significant factor in the vaginal microenvironment, and data are emerging on its independent role in urogenital health. Condomless vaginal intercourse and personal lubricant use are...

(024) A Randomized Trial on the Sexual Effectiveness and Impact on the Vaginal Microbiome of Reformulated Personal Water Lubricants with Lowered Osmolality and pH in Premenopausal and Postmenopausal Women

Abstract Introduction Vaginal dryness may be associated with postmenopausal women; however, it may also occur due to chronic medical conditions and as a direct side effect from medications. Personal lubricants can address sexual complaints and symptomatology associated with vaginal dryness, although clinically published data supporting their efficacy remains limited. Age-associated vaginal-physiological changes due to hypoestrogenic milieux include increased pH, decreased natural lubrication, reduced endothelial rugae and altered vaginal microbiome. While personal lubricants may alleviate symptoms, their definitive effects on the vaginal microbiome remain understudied and underappreciated. Objective This study examined reformulated water-based lubricants (lowered osmolalities and pH,) and their effect on female sexual function compared to their counterparts (higher osmolalities/increased pH). A secondary analysis examined if these reformulated lubricants influenced the vaginal microbiome of women from different age groups. Methods An open-label, parallel-design study was performed in heterosexual women in stable monogamous relationships, aged 18–65 years with mild-to-moderate vaginal dryness and dyspareunia. The study population (n=174) included an approximate 50:50 ratio of premenopausal to postmenopausal women. The randomization schedule was stratified by menopausal status. Subjects were randomized to use one of five water-based lubricants and instructed to use their lubricant during vaginal intercourse at least once a week over a 4-week period. The Female Sexual Function Index (FSFI) measured sexual functioning after 4 weeks of use as an indicator of lubricant performance. More than a 4-point increase in total FSFI is deemed clinically important. From the study-enrolled subjects, 50 females were randomized to one of five lubricant treatment groups for secondary microbiome analysis. To this end, four vaginal swabs per participant were sampled during pre- (“baseline”) and post- (“2 hours”, “24 hours” and “4 weeks”) lubricant application to assess bacterial diversity via 16S sequencing. Additionally, vaginal moisture and pH measurements were collected at baseline, 2 hours, and 24 hours post-lubricant application and correlated with microbiome diversity and richness using non-parametric tests and linear mixed models. Results An increase in FSFI total score of >4 points was found for all lubricants in the total population and for 4/5 lubricants in the premenopausal subgroup, as indicated by the mean differences to baseline. The number of subjects in sexual function (total FSFI >26.55) after treatment was significantly greater than the number in sexual function before treatment for both subgroups (premenopausal 19.3% to 78.4%; postmenopausal 22.3% to 75.3%; p<0.0001 for both). Lactobacillus species and Gardnerella vaginalis were the predominant taxa across all participants. Repeated lubricant applications did not alter the vaginal microbiome for up to 4 weeks post-product applications. Microbial diversity and relative abundance differed significantly between age groups but remained unaffected during product applications. Relative abundance of Lactobacilli spp. negatively correlated with vaginal pH while that of Gardnerella spp. showed a positive correlation with vaginal pH across all age groups. Conclusions These reformulated lubricants can be used not only to relieve symptomatology of vaginal dryness and dyspareunia, but to enhance overall sexual satisfaction regardless of menopausal status. These study lubricants demonstrated no significant impact on vaginal microbiome. Further studies with larger samples are warranted. Disclosure Yes, this is sponsored by industry/sponsor: Reckitt Benckiser Health. Clarification: Industry funding only - investigator initiated and executed study. Any of the authors act as a consultant, employee or shareholder of an industry for: Reckitt Benckiser Health.

Evaluation of the Effect of Water-Based Lubricants on the Vaginal Microbiome of Premenopausal and Postmenopausal Women [ID: 1376703

INTRODUCTION: Over-the-counter personal lubricants are available to relieve intimate discomfort associated with vaginal dryness. However, little is known about how personal lubricants may affect the vulvovaginal microbiome. METHODS: The present study recruited 50 premenopausal and postmenopausal women with mild-to-moderate vaginal dryness and dyspareunia. Participants were randomized to one of five lubricant treatment groups (of ranging osmolality and pH), stratified to account for menopausal status, and instructed to use their assigned lubricant during vaginal intercourse at least once a week over a 4-week period. A total of four vaginal swabs were sampled per participant pre (“baseline”)- and post (“2 hours,” “24 hours,” and “4 weeks”)-lubricant application to assess bacterial and fungal microbiome diversity via 16S (V3-V4) and ITS1 rRNA sequencing, respectively. The 301x2 paired-end reads were preprocessed to remove nonbiological and poor-quality reads using the dada2 package in RStudio. Cleaned reads were converted into Amplicon Sequence Variants (ASV) and classified using the SILVA rRNA gene database for bacteria, and the UNITE database for fungi. ASV counts were normalized to relative abundance as a function of total number of ASV per sample. RESULTS: Nonparametric ordination methods and multivariate analysis of variance showed that repeated application of all lubricants tested, did not significantly alter the vaginal microbiome for up to 4 weeks after product application. Microbiome diversity and relative abundance differed significantly between premenopausal and postmenopausal women but remained unchanged before and after lubricant application. CONCLUSION: Overall, lubricant use was associated with maintenance of the vaginal microbiome, regardless of the participant's menopausal status.

Fertility Knowledge and Educational Experiences of Graduating Medical Students: A Multi-Institution Survey [ID: 1363003

INTRODUCTION: There is a paucity of data regarding medical students' knowledge and education in fertility and reproductive life planning (RLP). Our goal was to assess fertility knowledge and educational experiences of graduating medical students to determine knowledge gaps and goals for future educational interventions. METHODS: Institutional review board-waived, online cross-sectional questionnaire was disseminated to graduating medical students at five participating institutions. RESULTS: The survey was distributed to 815 graduating medical students, and 117 (14.4%) completed the survey. Twenty-three (22%) overestimated the age of most precipitous fertility decline and 50 (52%) overestimated the chance of getting pregnant for a 40-year-old couple. One-third of students (30, 32%) incorrectly believe that physicians have equivalent infertility rates to the general population. Students were less cognizant of male fertility issues, incorrectly believing there was no negative effect on male fertility by age (43, 42%), certain sexual lubricants (73, 72%), and gonorrhea or chlamydia infections (45, 44%). Seventy-five (81%) report less than 5 hours of fertility-related education in medical school. Only 30 (32%) are satisfied or very satisfied with the fertility and family-building education they received. In an open-response survey question, students expressed interest in more education on transgender and cancer patient care, fertility preservation, assisted reproductive technologies, and RLP for medical professionals. CONCLUSION: This study identified deficits in medical student knowledge regarding fertility and RLP. This poses an opportunity for medical training programs to improve the amount and content of fertility-related education, both for their students' personal RLP and their ability to provide accurate, effective counseling for their patients.

A Randomized Trial on the Effectiveness of Five Water-Based Personal Lubricants in Premenopausal and Postmenopausal Women [ID: 1376759

INTRODUCTION: Vaginal dryness is generally associated with postmenopausal women; however, it may occur at all ages. Personal lubricants can relieve discomfort associated with vaginal dryness, although clinical data supporting the efficacy of many lubricants are limited. METHODS: An open-label, parallel-design study was performed in heterosexual women in monogamous relationships, aged 18–65 years with mild-to-moderate vaginal dryness and dyspareunia. The study population (n=174) included an approximate 50:50 ratio of premenopausal to postmenopausal women. The randomization schedule was stratified by menopausal status. Participants were randomized to use one of five water-based lubricants and instructed to use their lubricant during vaginal intercourse at least once a week over a 4-week period. The Female Sexual Function Index (FSFI) measured sexual functioning after 4 weeks of use as an indicator of lubricant performance. The total FSFI comprises six domains: desire, arousal, lubrication, orgasm, satisfaction, and pain reduction. A greater than 4-point increase in total FSFI is considered clinically important. RESULTS: An increase in FSFI total score of greater than 4 points was found for all lubricants in the total population and for four of five lubricants in the premenopausal subgroup, as indicated by the mean differences to baseline. The number of participants in sexual function (total FSFI >26.55) after treatment was significantly greater than the number in sexual function before treatment for both subgroups (premenopausal, 19.3–78.4%; postmenopausal, 22.3–75.3%; P<.0001 for both). CONCLUSION: These lubricants can be used not only to relieve symptomatology of vaginal dryness and dyspareunia, but to enhance overall sexual satisfaction regardless of menopausal status.

Sexual dysfunctions in breast cancer patients: evidence in context.

In breast cancer patients, endocrine therapy may exert a negative impact on sexual functioning in both genders, with potentially relevant consequences concerning quality of life and treatment adherence. The availability of effective interventions to maintain and/or restore sexual health in breast cancer patients is a key issue to a research agenda. To summarize and critically discuss the most updated and qualitatively relevant literature on the therapeutic approach to sexual impairment in breast cancer patients, with a focus on patients treated with endocrine therapy. We searched PubMed from its inception to February 2022 for observational and intervention trials including participants with sexual dysfunctions. We were particularly interested in studies of breast cancer patients with sexual dysfunctions while undergoing endocrine therapy. We developed a search strategy with the aim of maximizing the number of articles considered for screening and potential inclusion. Forty-five studies were selected: 3 observational and 42 intervention studies. Thirty-five studies were exclusively focused on female breast cancer populations. We could not identify studies exclusively focused on or also including male breast cancer patients. Overall, in female patients, the available armamentarium encompasses vaginal lubricants, moisturizers, estrogens, dehydroepiandrosterone, CO2 laser, ospemifene, and counseling. None of these interventions has been demonstrated to completely solve sexual dysfunctions when singularly considered. More favorable outcomes have come from the combination of different therapies. In female breast cancer, future research is oriented toward the gain of evidence on combined therapies and long-term data on safety issues on the most promising interventions. The lack of evidence on sexual disturbances in male breast cancer patients remains a major concern.

Positive Control(s) in Polyurethane Condom-Lubricant Compatibility Testing

Abstract Despite the proliferation of over-the-counter (OTC) personal lubricants (PLs) in the last two decades, to date, no known positive control has been identified to assess the compatibility of these PLs with polyurethane (PU) condoms. In the absence of suitable positive controls, PU condom compatibility with OTC PLs is assessed using a method built for testing compatibility of latex condoms with PLs. Herein, we attempt to identify a safe-to-handle positive control(s) for determining PU condom-lubricant compatibility. At room temperature (RmT), swelling of and induced stress in PU condom sample coupons were studied at various strain rates after discrete applications of a few ingredients common in commercial PLs. Additionally, stress reduction at a constant stretch was measured at 37°C. At low strain rates, changes in the induced stress and stress-to-strain ratio were detectable because of ingredients, e.g., hydroxy-terminated poly(dimethyl siloxane) of viscosity 25 cSt that caused substantial swelling of the condom materials at RmT, indicating prospective positive controls. At 37 °C, the percent stress reduction in PU samples under constant stretch was significant, with a few PL ingredients that did not significantly swell the PU material at RmT. Ingredients that enable significant stress reduction can serve as positive controls in PU condom-lubricant compatibility testing using the tensile method, provided the strain rate is comparable to the rate of condom-lubricant interaction, as evidenced by swelling study. At RmT, absence of swelling and insignificant changes in tensile properties at high strain rates do not guarantee the absence of interactions. Instead of testing mineral oil on latex condoms, manufacturers may now use a PU condom-specific positive control, when testing compatibility of PU condoms with OTC PLs.

Therapeutic Choices for Genitourinary Syndrome of Menopause (GSM) in Breast Cancer Survivors: A Systematic Review and Update.

(1) Background: Genitourinary syndrome of menopause (GSM) is a medical condition that can affect breast cancer survivors (BCS). This is a complication that often can occur as a result of breast cancer treatment, causing symptoms such as vaginal dryness, itching, burning, dyspareunia, dysuria, pain, discomfort, and impairment of sexual function. BCS who experience these symptoms negatively impact multiple aspects of their quality of life to the point that some of them fail to complete adjuvant hormonal treatment; (2) Methods: In this systematic review of the literature, we have analyzed possible pharmacological and non-pharmacological treatments for GSM in BCS. We reviewed systemic hormone therapy, local hormone treatment with estrogens and androgens, the use of vaginal moisturizers and lubricants, ospemifene, and physical therapies such as radiofrequency, electroporation, and vaginal laser; (3) Results: The data available to date demonstrate that the aforementioned treatments are effective for the therapy of GSM and, in particular, vulvovaginal atrophy in BCS. Where possible, combination therapy often appears more useful than using a single line of treatment; (4) Conclusions: We analyzed the efficacy and safety data of each of these options for the treatment of GSM in BCS, emphasizing how often larger clinical trials with longer follow-ups are needed.

A randomized trial on the effectiveness and safety of 5 water-based personal lubricants.

A range of personal lubricants with different formulations and subsequent properties are available for relief of discomfort associated with vaginal dryness; however, there are limited clinical data to support the efficacy and safety of many commercially available lubricants. To determine the effectiveness and safety of 5 water-based personal lubricants for the relief of intimate discomfort associated with vaginal dryness in pre- and postmenopausal women: 4 that were formulated to meet the World Health Organization (WHO) guidelines for osmolality and pH and 1 preexisting lubricant of higher osmolality and pH. An open-label, parallel-design study was performed in women aged 18 to 65years with mild-to-moderate vaginal dryness and dyspareunia. Participants were randomized to 1 of 5 lubricants (A-E) from 3 brands (Durex, KY, Queen V). They were instructed to use their allocated lubricants during vaginal intercourse at least once a week over a 4-week period. The Female Sexual Function Index (FSFI) measured sexual functioning after 4weeks of use as an indicator of lubricant performance. The primary outcome was change from baseline in total FSFI score after 4weeks of product use. A total of 174 women completed the study. The primary end point-a prespecified increase in FSFI ≥4 points from baseline after 4weeks of use-was met by all 5 lubricants tested. A statistically significant improvement was observed across all 6 domains of the FSFI from baseline to 4weeks of use with all 5 lubricants (P < .0001 for lubrication and pain reduction and P < .05 for all other domains). No serious adverse events occurred in the study, and the tolerance of all 5 lubricants was good/very good. The efficacy and safety of the tested lubricants are not compromised when formulated to meet the WHO criterion of osmolality ≤1200mOsm/kg. The lubricants tested in this investigation can be used not only to relieve symptomatology of vaginal dryness and dyspareunia but also to enhance overall sexual satisfaction. This study provides clinical evidence for the efficacy and safety of 5 lubricants, including those formulated to meet WHO guidelines, in relieving symptoms of vaginal dryness and improving the overall sexual experience. The open-label design may have introduced bias into the study. All 5 lubricants, including those formulated to be compliant with guidelines on pH and osmolality, can be considered effective and well tolerated for the relief of discomfort associated with vaginal dryness.

Condomless vaginal intercourse and lubricant use are independently associated with antioxidants within the vaginal tract

The vaginal metabolome provides broad-spectrum protection against urogenital infections through the action of key immunomodulatory metabolites such as lactic acid. It is unknown if vaginal intercourse and lubricant use affect the vaginal metabolome.

Effects of retinoid-loaded hyaluronic acid nanomicelles on vaginal epithelium in a murine menopause model.

This study aimed to develop hyaluronic acid (HA)-based, retinoic acid (RA)-containing nanomicelles and to investigate the effects of these newly developed nanomicelles on regeneration of the vaginal epithelium and aquaporin 3 (AQP3) expression in a murine menopause model. The HA-based, RA-loaded nanomicelles were developed, and the RA-loading rate, encapsulation efficiency, and hydrodynamic diameter were measured. Female BALB/c mice (8 weeks; n=30) were divided into control and experimental groups. Menopause was established in the experimental group by removing both ovaries. The experimental group was further divided into an ovariectomy group, an HA-C18 vehicle group, and an HA-C18-RA group (2.5 µg per mouse); vaginal administration of HA-C18 or HA-C18-RA was performed once daily. After 4 weeks of treatment, murine vaginal tissue was removed, and histological analysis was performed. Three drug-loaded nanomicelles were synthesized: the RA content in HA-C18-RA-10, HA-C18-RA-20, and HA-C18-RA-30 was 3.13%, 2.52%, and 16.67%, respectively, and the RA encapsulation efficiency was 95.57%, 83.92%, and 93.24%, respectively. In the experimental versus control group, serum estrogen levels were significantly reduced, and the vaginal mucosal epithelial layer was significantly thinner. After 4 weeks of treatment, the thickness of the vaginal mucosal epithelial layer and AQP3 expression was increased in the HA-C18-RA group compared with the HA-C18 vehicle group. The newly developed HA-based nanomicelles containing RA resulted in vaginal epithelial recovery and increased AQP3 expression. The results may contribute to the development of functional vaginal lubricants or moisturizers for the treatment of vaginal dryness.

Diagnostics and management of vulvovaginal atrophy according to the international guidelines

Vulvovaginal atrophy is one of the genitourinary symptoms caused by estrogen deficiency which leads to the development of immature vaginal epithelium, glycogen deficiency, reduction or even elimination of lactobacilli, and secondary genitourinary tract infection. Among the main symptoms were dryness, burning, itching, and dyspareunia. Diagnosis is typically based on the patient’s complaints, signs, and symptoms. Management of vulvovaginal atrophy includes various forms of topical estrogens and non-hormonal drugs. Low-dose vaginal estrogens can be used as monotherapy or as a supplement to hormone replacement therapy (HRT). In the case of monotherapy, there is no need to add progesterone for the endometrial protection. According to the recent studies, local vaginal estrogen therapy does not increase the risk of cancer, cardiovascular disease, and venous thromboembolism. On patients with hormonophobia, an alternative method of treatment is the use of vaginal lubricants and moisturizers or who have had cancers of various localization. For instance, usage of lactic acid vaginal gels in breast cancer survivors has improved vaginal dryness and dyspareunia as compared with the placebo. Yet, vaginal estrogen therapy has better clinical effects than non-hormonal drugs.

Treatment Strategies for Sexual Dysfunction Associated With Psychotropic Medications

&#x0D; For antipsychotic-related sexual dysfunction, 1 guideline recommends switching to aripiprazole or another non-hyperprolactinemic antipsychotic as the first option. Alternatively, the guideline recommends adjunctive treatment with aripiprazole, or switching to antipsychotics that have less impact on sexual function. Another guideline recommends adding estrogen or testosterone treatment to the antipsychotic medication to assist sexual dysfunction in women.&#x0D; For antidepressant-related sexual dysfunction, 1 guideline recommends switching to agomelatine or to a non-serotonergic drug or fluvoxamine as first option. Alternatively, the guideline recommends switching to a partially non-serotonergic antidepressant, adding antidotes, or using vaginal lubricants.&#x0D;

Local management strategies for inflammatory vaginitis in dermatologic conditions: Suppositories, dilators, and estrogen replacement

Prevalence of vaginal involvement in erosive lichen planus and pemphigus vulgaris has been reported in over 58% and up to 44% of patients, respectively.1Khurana A. Tandon S. Marfatia Y.S. Madnani N. Genital lichen planus: an underrecognized entity.Indian J Sex Transm Dis AIDS. 2019; 40: 105-112Crossref PubMed Google Scholar,2Kavala M. Topaloğlu Demir F. Zindanci I. et al.Genital involvement in pemphigus vulgaris (Pv): correlation with clinical and cervicovaginal Pap smear findings.J Am Acad Dermatol. 2015; 73: 655-659Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar While most dermatologists are comfortable utilizing ultrapotent steroids on the vulva, less are comfortable with managing vaginal inflammation. Here, we highlight 3 local strategies to target inflammatory vaginal dermatoses and prevent scarring (Fig 1). We recommend starting with 25-mg hydrocortisone acetate suppositories, available as rectal suppositories. Patients should be counseled to use vaginally instead of rectally. Suppositories are initiated nightly for 2 to 4 weeks and decreased to every other night, or 2 to 3 times per week depending on disease control. Patients should be evaluated monthly, and suppositories should be tapered to the lowest dose/frequency that maintains disease remission.2Kavala M. Topaloğlu Demir F. Zindanci I. et al.Genital involvement in pemphigus vulgaris (Pv): correlation with clinical and cervicovaginal Pap smear findings.J Am Acad Dermatol. 2015; 73: 655-659Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar If more potent suppositories are required, hydrocortisone can be compounded at doses of 100 to 200 mg. When prescribing suppositories, we recommend candidal prophylaxis, with topical antifungals 2 to 3 times per week or oral fluconazole 150 to 200 mg weekly. Insertion of dilators 3 times, weekly, to prevent adhesions. Dilators can be ordered online and come in sets of varying sizes. Patients should use the largest dilator comfortable, and vaginal moisturizers and lubricants can be utilized. Estrogen deficiency should be considered in postmenopausal patients as this can contribute to vaginal inflammation. Local estrogen therapy includes a ring, tablet, or cream. Generally, vaginal cream tends to have the least pain with insertion and is used nightly for 2 weeks with decrease to maintenance 1 to 3 times per week. None disclosed.

Dynamic, hollow nanotubular networks with superadjustable pH-responsive and temperature resistant rheological characteristics

Recently, the interest in stimuli-responsive and adaptable materials has continuously grown in various fields and applications. For such responsive systems, different triggers, including pH, light, pressure, temperature, and electric field, have been utilized to control dynamics and assembly. Among these, pH is one of the most convenient, energy-efficient, and economic modalities. Besides, plenty of traditional materials have poor thermal and salt stability, limiting their applications. Herein, we report a new design of a pH-responsive viscoelastic supramolecular complex (VSC) based on commplexation of a new long-chain amino-amide and maleic acid. The system demonstrated a sol–gel-sol transition from pH 2 to 10, with the largest static viscosity occurring at pH 6 (∼1000 Pa·s) and the smallest viscosity at pH 4 (∼3.3 Pa·s), indicating ∼ 300-fold control over the viscosity. For a given concentration, the static viscosity of VSC was about 15 times larger than that of CTAB/NaSal, a well-established dynamic viscoelastic system, and no pH-responsiveness was observed for the traditional system. In addition, the VSC demonstrated a superior temperature tolerance and lower temperature dependence. The potential of these intriguing dynamics viscoelastic systems was evaluated for hydraulic fracturing and enhanced oil recovery applications. Proppant settling velocity of DMAA/MA was 500 ∼ 1000 times lower than that of CTAB/NaSal and common traditional polymers. Likewise, the oil recovery percentage could be significantly improved with the utilization of DMAA/MA compared to the CTAB/NaSal (86 % vs 52 %). Aside from applications in hydraulic fracturing and enhanced oil recovery, we anticipate that the intriguing rheological properties of this viscoelastic system can be beneficial for other chemical engineering applications including personal care products, cosmetics, lubricants, and biomedical gels.

Synthetic Mucin Gels with Self-Healing Properties Augment Lubricity and Inhibit HIV-1 and HSV-2 Transmission.

Mucus is a self-healing gel that lubricates the moist epithelium and provides protection against viruses by binding to viruses smaller than the gel's mesh size and removing them from the mucosal surface by active mucus turnover. As the primary nonaqueous components of mucus (≈0.2%-5%, wt/v), mucins are critical to this function because the dense arrangement of mucin glycans allows multivalence of binding. Following nature's example, bovine submaxillary mucins (BSMs) are assembled into "mucus-like" gels (5%, wt/v) by dynamic covalent crosslinking reactions. The gels exhibit transient liquefaction under high shear strain and immediate self-healing behavior. This study shows that these material properties are essential to provide lubricity. The gels efficiently reduce human immunodeficiency virus type 1 (HIV-1) and genital herpes virus type 2 (HSV-2) infectivity for various types of cells. In contrast, simple mucin solutions, which lack the structural makeup, inhibit HIV-1 significantly less and do not inhibit HSV-2. Mechanistically, the prophylaxis of HIV-1 infection by BSM gels is found to be that the gels trap HIV-1 by binding to the envelope glycoprotein gp120 and suppress cytokine production during viral exposure. Therefore, the authors believe the gels are promising for further development as personal lubricants that can limit viral transmission.

Laser treatment for genitourinary syndrome of menopause: Scientific Impact Paper No. 72 (July 2022): Scientific Impact Paper No. 72 (July 2022).

Genitourinary syndrome of menopause (GSM) is the term used to describe the group of symptoms including vaginal pain, vaginal dryness, itching, pain during sexual intercourse and fragile vaginal tissues as well as urinary symptoms including urinary frequency, urgency, incontinence, blood in the urine (haematuria) and recurrent urinary tract infections that occur due to a lack of the hormone estrogen. These symptoms can have a significant negative impact on psychosexual issues, sexual function and quality of life in postmenopausal women. Traditionally women have been treated with vaginal lubricants, vaginal moisturisers or low-dose vaginal estrogens. Lasers have been used in the cosmetic industry for collagen remodelling and repair of the skin. Therefore, it has been suggested that laser therapy may be used on the vagina as an alternative treatment for GSM. A review of all the published studies assessing the safety and efficacy of laser therapy for GSM have shown promising beneficial results. The majority of studies to date have been small, short-term, observational studies. However, there are randomised controlled trials underway. Laser treatment may be beneficial for the symptoms of GSM but until more robust evidence is available it should not be adopted into widespread practice, and should be used as part of a research study only.