Hyperinsulinemia is closely related to low urinary clearance of D-chiro-inositol in men with a wide range of insulin sensitivity

Biomedical applications of stimuli-responsive "smart" interpenetrating polymer network hydrogels

In recent years, owing to the ongoing advancements in polymer materials, hydrogels have found increasing applications in the biomedical domain, notably in the realm of stimuli-responsive "smart" hydrogels. Nonetheless, conventional single-network stimuli-responsive "smart" hydrogels frequently exhibit deficiencies, including low mechanical strength, limited biocompatibility, and extended response times. In response, researchers have addressed these challenges by introducing a second network to create stimuli-responsive "smart" Interpenetrating Polymer Network (IPN) hydrogels. The mechanical strength of the material can be significantly improved due to the topological entanglement and physical interactions within the interpenetrating structure. Simultaneously, combining different network structures enhances the biocompatibility and stimulus responsiveness of the gel, endowing it with unique properties such as cell adhesion, conductivity, hemostasis/antioxidation, and color-changing capabilities. This article primarily aims to elucidate the stimulus-inducing factors in stimuli-responsive "smart" IPN hydrogels, the impact of the gels on cell behaviors and their biomedical application range. Additionally, we also offer an in-depth exposition of their categorization, mechanisms, performance characteristics, and related aspects. This review furnishes a comprehensive assessment and outlook for the advancement of stimuli-responsive "smart" IPN hydrogels within the biomedical arena. We believe that, as the biomedical field increasingly demands novel materials featuring improved mechanical properties, robust biocompatibility, and heightened stimulus responsiveness, stimuli-responsive "smart" IPN hydrogels will hold substantial promise for wide-ranging applications in this domain.

Inositols in the ovaries: activities and potential therapeutic applications

INTRODUCTION

Myo-inositol (MI) and d-chiro-inositol (DCI) play a key role in ovarian physiology, as they are second messengers of insulin and gonadotropins. Ex-vivo and in-vitro experiments demonstrate that both isomers are deeply involved in steroid biosynthesis, and that reduced MI-to-DCI ratios are associated with pathological imbalance of sex hormones.

AREAS COVERED

This expert opinion provides an overview of the physiological distribution of MI and DCI in the ovarian tissues, and a thorough insight of their involvement into ovarian steroidogenesis. Insulin resistance and compensatory hyperinsulinemia dramatically reduce the MI-to-DCI ratio in the ovaries, leading to gynecological disorders characterized by hyperandrogenism, altered menstrual cycle and infertility.

EXPERT OPINION

Available evidence indicates that MI and DCI have very specific physiological roles and, seemingly, physiological MI-to-DCI ratios in the ovaries are crucial to maintain the correct homeostasis of steroids. Inositol treatments should be evaluated on the patients' specific conditions and needs, as long-term supplementation of high doses of DCI may cause detrimental effects on the ovarian functionality. In addition, the effects of inositol therapy on the different PCOS phenotypes should be further investigated in order to better tailor the supplementation.

Reproductive Health in First-degree Relatives of Patients With Polycystic Ovary Syndrome: A Review and Meta-analysis

CONTEXT

Polycystic ovary syndrome (PCOS) is a highly heritable disease. Emerging evidence elucidated the elevated prevalence of reproductive abnormalities in first-degree relatives (FDRs) of patients with PCOS.

OBJECTIVE

To explore the reproductive health in FDRs of patients with PCOS.

METHODS

Ten databases were searched in December 2020 (PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Chinese Biological Medical Literature, Chinese National Knowledge Infrastructure, Chinese Journals Full-text Database, WanFang, and World Health Organization international clinical trials registry platform). This study included cohort, case-control, or cross-sectional studies. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement was followed. Dichotomous data from each of the eligible studies were combined by the Mantel-Haenszel model. Standard mean differences with 95% CIs were assessed. Heterogeneities were assessed using I2 statistics, and the quality of evidence was evaluated by a US Agency for Healthcare Research and Quality Evidence-based Practice Center program and Grading of Recommendations, Assessment, Development and Evaluation approach.

RESULTS

Thirty-eight studies were included. The prevalence of PCOS (0.22; 95% CI, 0.16 to 0.29), menstrual irregularities (0.28; 95% CI, 0.22 to 0.34, P < .01), and ovary morphological changes were elevated in female PCOS FDRs. Female FDRs also presented with increased levels of luteinizing hormone, total testosterone (standard mean difference, 0.53; 95% CI, 0.28 to 0.78, P < .01), unconjugated testosterone, free androgen index, dehydroepiandrosterone sulfate (DHEAS), and antimüllerian hormone levels. Subgroup analyses indicated that some of these changes begun in pubertal girls. Furthermore, fathers of PCOS patients had a higher risk of premature baldness. The DHEAS level was elevated in male FDRs.

CONCLUSION

The findings of this analysis suggested that FDRs of patients with PCOS suffered from reproductive endocrinological dysregulations. Thus, more attention should be focused on this population.

Synthesis of polymer macrogels with rapid and significant response to glucose concentration changes

Polymer macrogels with rapid and significant responses to glucose concentration changes were made of a poly(phenylboronic acid) microgel array tethered chemically to bridging polymers.

The "Other" Inositols and Their Phosphates: Synthesis, Biology, and Medicine (with Recent Advances in myo-Inositol Chemistry)

Cell signaling via inositol phosphates, in particular via the second messenger myo-inositol 1,4,5-trisphosphate, and phosphoinositides comprises a huge field of biology. Of the nine 1,2,3,4,5,6-cyclohexanehexol isomers, myo-inositol is pre-eminent, with "other" inositols (cis-, epi-, allo-, muco-, neo-, L-chiro-, D-chiro-, and scyllo-) and derivatives rarer or thought not to exist in nature. However, neo- and d-chiro-inositol hexakisphosphates were recently revealed in both terrestrial and aquatic ecosystems, thus highlighting the paucity of knowledge of the origins and potential biological functions of such stereoisomers, a prevalent group of environmental organic phosphates, and their parent inositols. Some "other" inositols are medically relevant, for example, scyllo-inositol (neurodegenerative diseases) and d-chiro-inositol (diabetes). It is timely to consider exploration of the roles and applications of the "other" isomers and their derivatives, likely by exploiting techniques now well developed for the myo series.

Glucose-responsive microgels based on apo-enzyme recognition

Glucose-responsive microgels that can undergo reversible and rapid volume phase transitions were made of apo-glucose oxidase interpenetrated in a poly(N-isopropylacrylamide) network.

Modulatory role of D-chiro-inositol (DCI) on LH and insulin secretion in obese PCOS patients

Polycystic ovary syndrome (PCOS) is a common endocrine condition that affects fertility through oligo-ovulation, hyperandrogenism and polycystic morphology of the ovaries. Since it has been demonstrated a high incidence of insulin resistance in PCOS patients, our study aimed to evaluate the efficacy of the integrative treatment with D-chiro-inositol (DCI) (500 mg die, per os, for 12 weeks) on hormonal parameters and insulin sensitivity in a group of overweight/obese PCOS patients (body mass index; BMI > 26). After the treatment, interval several endocrine parameters improved (luteinizing hormone [LH], LH/follicle stimulating hormone [FSH], androstenedione and insulin), insulin response to oral glucose tolerance test reported the significant improvement of insulin sensitivity as well as the gonadotropin-releasing hormone (GnRH)-induced (10 µg, in bolus) LH response. BMI decreased, though no lifestyle modification was requested. When data were analyzed according to the presence or absence of first-grade diabetic relatives, PCOS patients with diabetic relatives showed greater improvement after DCI administration. In conclusion DCI administration is effective in restoring better insulin sensitivity and an improved hormonal pattern in obese hyperinsulinemic PCOS patients, in particular, in hyperinsulinemic PCOS patients who have diabetic relatives.

Synthesis and volume phase transition of concanavalin A-based glucose-responsive nanogels

A glucose-responsive nanogel that can undergo reversible and rapid volume phase transitions is made of ConA interpenetrated in a poly(NIPAM) network.

Responsive materials for self-regulated insulin delivery

With diabetes mellitus becoming an important public health concern, insulin-delivery systems are attracting increasing interest from both scientific and technological researchers. This feature article covers the present state-of-the-art glucose-responsive insulin-delivery system (denoted as GRIDS), based on responsive polymer materials, a promising system for self-regulated insulin delivery. Three types of GRIDS are discussed, based on different fundamental mechanisms of glucose-recognition, with: a) glucose enzyme, b) glucose binding protein, and c) synthetic boronic acid as the glucose-sensitive component. At the end, a personal perspective on the major issues yet to be worked out in future research is provided.