Diabetic ulcer is the most common kind of chronic wound worldwide. Though great efforts have been devoted, diabetic ulcer still remains as a challenge that requires constant monitoring and management. In this work, a multifunctional zwitterionic hydrogel is developed to simultaneously detect two fluctuant wound parameters, pH and glucose level, to monitor the diabetic wound status. A pH indicator dye (phenol red) and two glucose sensing enzymes, glucose oxidase (GOx) and horseradish peroxidase (HRP), are encapsulated in the anti-biofouling and biocompatible zwitterionic poly-carboxybetaine (PCB) hydrogel matrix. The visible images are collected by a smartphone and transformed into RGB signals to quantify the wound parameters. Results show that the activity and stability of both two enzymes are improved within PCB hydrogel, and the K cat /K m value of PCB-HRP is ≈5.5 fold of free HRP in artificial wound exudate. This novel wound dressing can successfully monitor the pH range of 4-8 and glucose level of 0.1-10 × 10 −3 m. Meanwhile, it also provides a moist healing environment that can promote diabetic wound healing. This multifunctional wound dressing may open vistas in chronic wound management and guide the diabetes treatment in clinical applications.

Objectives: To describe the clinical characteristics of patients in a Fangcang Hospital. Methods: Non-critically ill individuals with positive SARS-CoV-2 RT-PCR tests admitted between 7 February and 12 February 2020 to Dongxihu Fangcang Hospital, which was promptly constructed because of the rapid, exponential increase in COVID-19 patients in Wuhan, China, were included; clinical course through to 22 February was recorded. Results: A total of 1012 non-critically ill individuals with positive SARS-CoV-2 RT-PCR tests were included in the study. Thirty (of 1012, 3.0%) individuals were asymptomatic on admission. During hospitalization, 16 of 30 (53.3%) asymptomatic individuals developed different symptoms. Fourteen of 1012 patients (1.4%) remained asymptomatic from exposure to the end of follow up, with a median duration of 24 days (interquartile range 22e27). Fever (761 of 1012, 75.2%) and cough (531 of 1012, 52.4%) were the most common symptoms. Small patchy opacities (355 of 917, 38.7%) and ground-glass opacities (508 of 917, 55.4%) were common imaging manifestations in chest CT scans. One hundred patients (9.9%) were transferred to designated hospitals due to aggravation of illness. Diarrhoea emerged in 152 of 1012 patients (15.0%). Male, older age, diabetes, cardiovascular diseases, chills, dyspnoea, SO 2 value of 93%, white blood cell counts of >10 Â 10 9 /L and large consolidated opacities on CT images were all risk factors for aggravation of illness. Conclusions: Non-critically ill individuals had different clinical characteristics from critically ill individuals. Asymptomatic infections only accounted for a small proportion of COVID-19. Although with a low incidence, diarrhoea was observed in patients with COVID-19, indicating the possibility of faecal eoral transmission.

Conductive hydrogels have emerged as fascinating materials applied in flexible electronics because of their integrated conductivity and mechanical flexibility. However, the large amounts of water in conductive hydrogels inevitably freeze at subzero temperature, causing a reduction of their ionic transport ability and elasticity. Herein, the bioinspired antifreezing agents—zwitterionic osmolytes (e.g., betaine, proline) are first proposed to prevent ammonium chloride‐containing Ca‐alginate/polyacrylamide hydrogels from freezing. With a facile one‐pot solvent displacement method, the zwitterionic osmolytes can displace the water molecules inside the hydrogels. Due to the excellent freeze tolerance of zwitterionic osmolytes, the resulting zwitterionic osmolyte‐based hydrogels exhibit outstanding ionic conductivity (up to ≈2.7 S m−1) at −40 °C, which exceeds the conductivities of most reported conductive hydrogels. Meanwhile, they present stable mechanical flexibility over a wide temperature range (−40 to 25 °C). More importantly, two types of the resulting hydrogel‐based flexible electronics, including a capacitive sensor and a resistive sensor, can maintain their response function at −40 °C. This work offers a new solution to fabricate conductive hydrogels with antifreezing ability, which can broaden the working temperature range of flexible electronics.

The term “zwitterionic polymers” refers to polymers that bear a pair of oppositely charged groups in their repeating units. When these oppositely charged groups are equally distributed at the molecular level, the molecules exhibit an overall neutral charge with a strong hydration effect via ionic solvation. The strong hydration effect constitutes the foundation of a series of exceptional properties of zwitterionic materials, including resistance to protein adsorption, lubrication at interfaces, promotion of protein stabilities, antifreezing in solutions, etc. As a result, zwitterionic materials have drawn great attention in biomedical and engineering applications in recent years. In this review, we give a comprehensive and panoramic overview of zwitterionic materials, covering the fundamentals of hydration and nonfouling behaviors, different types of zwitterionic surfaces and polymers, and their biomedical applications.