This review highlights recent advances towards non-invasive and continuous glucose monitoring devices, with a particular focus placed on monitoring glucose concentrations in alternative physiological fluids to blood.

Glucose Sensing for Diabetes Monitoring: Recent Developments.

Improving the safety efficacy ratio of existing drugs is a current challenge to be addressed rather than the development of novel drugs which involve much expense and time. The efficacy of drugs is affected by a number of factors such as their low aqueous solubility, unequal absorption along the gastrointestinal (GI) tract, risk of degradation in the acidic milieu of the stomach, low permeation of the drugs in the upper GI tract, systematic side effects, etc. This review aims to enlighten readers on the role of pH sensitive hydrogels in drug delivery, their mechanism of action, swelling, and drug release as a function of pH change along the GI tract. The basis for the selection of materials, their structural features, physical and chemical properties, the presence of ionic pendant groups, and the influence of their pKa and pKb values on the ionization, consequent swelling, and targeted drug release are also highlighted.

https://www.mdpi.com/2073-4360/9/4/137/pdf

pH Sensitive Hydrogels in Drug Delivery: Brief History, Properties, Swelling, and Release Mechanism, Material Selection and Applications

pH-sensing materials and configurations are rapidly evolving toward exciting new applications, especially those in biomedical applications. In this review, we highlight rapid progress in electrochemical pH sensors over the past decade (2008–2018) with an emphasis on key considerations, such as materials selection, system configurations, and testing protocols. In addition to recent progress in optical pH sensors, our main focus in this review is on electromechanical pH sensors due to their significant advances, especially in biomedical applications. We summarize developments of electrochemical pH sensors that by virtue of their optimized material chemistries (from metal oxides to polymers) and geometrical features (from thin films to quantum dots) enable their adoption in biomedical applications. We further present an overview of necessary sensing standards and protocols. Standards ensure the establishment of consistent protocols, facilitating collective understanding of results and building on the current...

Recent Progress in Electrochemical pH-Sensing Materials and Configurations for Biomedical Applications

Following a single blind, cross-over and non-randomized design we investigated the effect of 7-day use of chlorhexidine (CHX) mouthwash on the salivary microbiome as well as several saliva and plasma biomarkers in 36 healthy individuals. They rinsed their mouth (for 1 min) twice a day for seven days with a placebo mouthwash and then repeated this protocol with CHX mouthwash for a further seven days. Saliva and blood samples were taken at the end of each treatment to analyse the abundance and diversity of oral bacteria, and pH, lactate, glucose, nitrate and nitrite concentrations. CHX significantly increased the abundance of Firmicutes and Proteobacteria, and reduced the content of Bacteroidetes, TM7, SR1 and Fusobacteria. This shift was associated with a significant decrease in saliva pH and buffering capacity, accompanied by an increase in saliva lactate and glucose levels. Lower saliva and plasma nitrite concentrations were found after using CHX, followed by a trend of increased systolic blood pressure. Overall, this study demonstrates that mouthwash containing CHX is associated with a major shift in the salivary microbiome, leading to more acidic conditions and lower nitrite availability in healthy individuals.

/pdf/effects-of-chlorhexidine-mouthwash-on-the-oral-microbiome-2f4vupg97s.pdf

Effects of chlorhexidine mouthwash on the oral microbiome

Fluoride is ubiquitously present throughout the world. It is released from minerals, magmatic gas, and industrial processing, and travels in the atmosphere and water. Exposure to low concentrations of fluoride increases overall oral health. Consequently, many countries add fluoride to their public water supply at 0.7–1.5 ppm. Exposure to high concentrations of fluoride, such as in a laboratory setting often exceeding 100 ppm, results in a wide array of toxicity phenotypes. This includes oxidative stress, organelle damage, and apoptosis in single cells, and skeletal and soft tissue damage in multicellular organisms. The mechanism of fluoride toxicity can be broadly attributed to four mechanisms: inhibition of proteins, organelle disruption, altered pH, and electrolyte imbalance. Recently, there has been renewed concern in the public sector as to whether fluoride is safe at the current exposure levels. In this review, we will focus on the impact of fluoride at the chemical, cellular, and multisystem level, as well as how organisms defend against fluoride. We also address public concerns about fluoride toxicity, including whether fluoride has a significant effect on neurodegeneration, diabetes, and the endocrine system.

Principles of fluoride toxicity and the cellular response: a review.

Objectives: Saliva contains a variety of host defense factors It influences calculus formation and periodontal disease Different studies have been done to find exact correlation of salivary biomarkers with periodontal disease With a multitude of biomarkers and complexities in their determination, the salivary pH may be tried to be used as a quick chairside test The aim of this study was to analyze the pH of saliva and determine its relevance to the severity of periodontal disease Study Design: The study population consisted of 300 patients They were divided into three groups of 100 patients each: Group A had clinically healthy gingiva, Group B who had generalized chronic gingivitis and Group C who had generalized chronic periodontitis The randomized unstimulated saliva from each patient was collected and pH was tested Data was analyzed statistically using analysis of variance technique Results: The salivary pH was more alkaline for patients with generalized chronic gingivitis as compared with the control group ( P = 0001) whereas patients with generalized chronic periodontitis had more acidic pH as compared with the control group ( P = 0001) Conclusion: These results indicate a significant change in the pH depending on the severity of the periodontal condition The salivary pH shows significant changes and thus relevance to the severity of periodontal disease Salivary pH may thus be used as a quick chairside diagnostic biomarker

Salivary pH: A diagnostic biomarker.

Introduction: Periodontitis is an inflammatory disease of the periodontium. Reactive oxygen species (ROS) are produced via the bacteria-host mediated pathway inducing tissue breakdown. The removal of ROS by antioxidant (AO) defence systems is essential for healthy aerobic life. Within mammalian tissues, the most significant antioxidant is superoxide dismutase (SOD), which is released as a homeostatic mechanism to protect the tissues, and it can be detected in extra- and intracellular compartments. Aims and Objectives: The purpose of this study was to examine erythrocyte SOD in patients with generalized chronic periodontitis compared to the healthy controls. Materials and Methods: A total of 96 individuals were recruited for the study. The test group consisted of 58 patients diagnosed with chronic periodontitis with an average age of 42.1 ± 9.3 years. The healthy control group included 31 males and 7 females with an average age of (42.1 ± 7.7) years. The periodontal status of all individuals were evaluated by measurements of probing depth (PD), clinical attachment level (CAL), gingival index (GI) 20 and plaque index (PI) 21 in both the groups. PD and CAL were measured on six sites of teeth. Erythrocyte - SOD activity was measured by Ransod kit. Results: All the clinical parameters were found to be significantly higher in the CP group compared with the control group ( P P Conclusion: This study indicated that enhanced activities of SOD in erythrocytes which could be related to a greater degree of oxidative stress in patients with chronic periodontitis.

Sharmila Baliga

Papers

Salivary pH: A diagnostic biomarker.

Estimation of superoxide dismutase levels in chronic periodontitis patients: A clinical and biochemical study