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This review describes some commercially available stimuli-responsive polymers of natural and synthetic origin, and their applications in drug delivery and textiles. The polymers of natural origin such as chitosan, cellulose, albumin, and gelatin are found to show both thermo-responsive and pH-responsive properties and these features of the biopolymers impart sensitivity to act differently under different temperatures and pH conditions. The stimuli-responsive characters of these natural polymers have been discussed in the review, and their respective applications in drug delivery and textile especially for textile-based transdermal therapy have been emphasized. Some practically important thermo-responsive polymers such as pluronic F127 (PF127) and poly(N-isopropylacrylamide) (pNIPAAm) of synthetic origin have been discussed in the review and they are of great importance commercially because of their in situ gel formation capacity. Some pH-responsive synthetic polymers have been discussed depending on their surface charge, and their drug delivery and textile applications have been discussed in this review. The selected stimuli-responsive polymers of synthetic origin are commercially available. Above all, the applications of bio-based or synthetic stimuli-responsive polymers in textile-based transdermal therapy are given special regard apart from their general drug delivery applications. A special insight has been given for stimuli-responsive hydrogel drug delivery systems for textile-based transdermal therapy, which is critical for the treatment of skin disease atopic dermatitis.

The past decade has seen considerable growth in the development of materials for fuel cell electrodes, and there is a desire for active electrocatalysts derived from base metals instead of noble metals. Fuels cells that consume H 2 and O 2 require catalysts to cleave these reactants, with the oxygen reduction reaction (ORR) — either 4H + /4e − reduction to 2H 2 O or 2H + /2e − reduction to H 2 O 2 — being particularly challenging. The ORR is efficiently performed by certain metalloenzymes, and understanding the links between their structure and function aids the design of molecular ORR electrocatalysts. These bio-inspired catalysts exhibit good activity relative to previous synthetic systems and, furthermore, have provided mechanistic insights relevant to synthetic and enzymatic catalysts. This Review covers recent developments in homogeneous and heterogeneous molecular ORR catalysis, placing emphasis on reaction mechanisms and the factors governing rates and selectivities. Electrocatalysts for the oxygen reduction reaction are important components of energy technologies such as fuel cells. The study of molecular catalysts affords mechanistic insights that further the development of robust, active and energy-efficient systems. This Review describes state-of-the-art metal complexes that operate either in solution or immobilized on an electrode.

Heme/porphyrin-based electrocatalysts (both synthetic and natural) have been known to catalyze electrochemical O ₂, H ⁺, and CO ₂ reduction for more than five decades. So far, no direct spectroscopic investigations of intermediates formed on the electrodes during these processes have been reported; and this has limited detailed understanding of the mechanism of these catalysts, which is key to their development. Rotating disk electrochemistry coupled to resonance Raman spectroscopy is reported for iron porphyrin electrocatalysts that reduce O ₂ in buffered aqueous solutions. Unlike conventional single-turnover intermediate trapping experiments, these experiments probe the system while it is under steady state. A combination of oxidation and spin-state marker bands and metal ligand vibrations (identified using isotopically enriched substrates) allow in situ identification of O ₂-derived intermediates formed on the electrode surface. This approach, combining dynamic electrochemistry with resonance Raman spectroscopy, may be routinely used to investigate a plethora of metalloporphyrin complexes and heme enzymes used as electrocatalysts for small-molecule activation.

Staphylococcus aureus causes numerous community-acquired and nosocomial infections in humans by exploiting biofilm. In this context, this study aims to impede the formation of Staphylococcus aureus biofilm by exposing the cells to a plant-based alkaloid, piperine. Our study revealed that piperine exhibited considerable antimicrobial activity against the test organism. However, we had tested the lower concentrations (up to 32 µg/mL) of piperine to observe whether they could show any antibiofilm activity against the same organism. Several experiments, like crystal violet (CV) assay, estimation of total biofilm protein, and fluorescence microscopic observations, established that lower concentrations (up to 16 µg/mL) of piperine showed efficient antibiofilm activity against Staphylococcus aureus. In this connection, we also noticed that the lower concentrations (8 and 16 µg/mL) of piperine showed a considerable reduction in microbial metabolic activity. Besides, it was also observed that the mentioned concentrations of piperine did not compromise the microbial growth of the target organism while exhibiting antibiofilm activity. To understand the underlying mechanism of microbial biofilm inhibition under the influence of piperine, we observed that the compound was found to accumulate reactive oxygen species in the bacterial cells that could play an important role in the inhibition of biofilm formation. Furthermore, the tested concentrations (8 and 16 µg/mL) of piperine were able to inhibit the motility of the test organism that might compromise the development of biofilm. Thus, piperine could be considered as a potential agent for the effective management of biofilm threat caused by Staphylococcus aureus.

Staphylococcus aureus causes several nosocomial and community-acquired infections in human host involving biofilm. Thus, strategies need to be explored to curb biofilm threats by either inhibiting the formation of biofilm or disintegrating the pre-existing biofilm. Towards this direction, we had already revealed the biofilm inhibiting properties of 1,4-naphthoquinone against S. aureus. In this study, we have investigated whether this compound can act on pre-existing biofilm. Hence, biofilm of S. aureus was developed first and challenged further with 1,4-naphthoquinone. Experiments such as crystal violet assay, fluorescence microscopy, and estimation of total biofilm protein were performed to confirm the biofilm disintegration properties of 1,4-naphthoquinone. The disintegration of pre-existing biofilm could be attributed to the generation of reactive oxygen species (ROS). To investigate further, we observed that extracellular DNA (eDNA) was found to play an important role in holding the biofilm network as DNaseI treatment could cause an efficient disintegration of the same. To examine the effect of ROS on the eDNA, we exposed pre-existing biofilm to either 1,4-naphthoquinone or a combination of both 1,4-naphthoquinone and ascorbic acid for different length of time. Post-incubation, ROS generation and the amount of eDNA associated with the biofilm were determined wherein an inversely proportional relationship was observed between them. The result indicated that with the increase of ROS generation, the amount of eDNA associated with biofilm got decreased substantially. Thus, the results indicated that the generation of ROS could degrade the eDNA thereby compromising the integrity of biofilm which lead to the disintegration of pre-existing biofilm.

Maintaining good indoor air quality is crucial in buildings dedicated to enhancing the health and well-being of their occupants. This challenge becomes even more complex due to the diverse range of users and spaces within a single institution. Different areas, such as operating rooms and waiting rooms, require specific air quality standards, tailored to the varying health conditions of patients and visitors. Poor air quality can hinder hospital staff in performing their duties effectively and affect patients' comfort during recovery. Hospitals can now achieve indoor air quality standards cost-effectively through Internet of Things (IoT) technology. The IoT enables remote monitoring, offering greater control over indoor conditions like air quality, temperature, humidity, and dust levels. This system monitors air quality, dust concentration, temperature, and humidity within healthcare facilities, sending notifications to staff via an app and push alerts when readings exceed normal levels. It utilizes the MQ135 sensor for air quality, the GP2Y1010AU0F optical dust sensor, and the DHT11 sensor for temperature and humidity, all interfaced with NodeMCU through the Arduino IDE. Data from these sensors is stored on a cloud platform and displayed in a mobile app, with near real-time monitoring from sensors placed throughout the facility. A time-series algorithm, such as Autoregressive Integrated Moving Average (ARIMA), is used to forecast temperature and humidity trends in wards. The system alerts staff when indoor temperature exceeds 27 °C, triggers warnings when air quality surpasses 500 ppm, and issues critical alerts for levels above 650 ppm. Sensor data, sent to the cloud every 120 s, provides staff with insights to better plan actions to improve indoor air quality. Article Highlights This system provides a comprehensive overview of hospital environments by tracking air quality, dust, temperature, and humidity simultaneously, offering a more complete picture of indoor conditions than systems that focus on fewer parameters. The use of IoT technology enables real-time monitoring and alerts, allowing hospital staff to respond immediately to any issues. Additionally, predictive analytics anticipate future changes, giving staff time to take preventive measures. The integration with a mobile app and cloud-based data storage ensures easy access to data, convenient monitoring, and the ability to scale the system across multiple hospital facilities, catering specifically to the unique needs of different healthcare environments.

Linseed oil which has various biomedical applications was encapsulated by chitosan (Chi)-based microcapsules in the development of a suitable carrier. Oil droplets formed in oil-in-water emulsion using sodium dodecyl sulfate (SDS) as emulsifier was stabilized by Chi, and microcapsules with multilayers were formed by alternate additions of SDS and Chi solutions in an emulsion through electrostatic interaction. No chemical cross-linker was used in the study and the multilayer shell membrane was formed by ionic gelation using Chi and SDS. The rigidification of the shell membrane of microcapsules was achieved by alkali treatment in the presence of a small amount of 1-butanol to reduce aggregation. A trisodium citrate solution was used to stabilize the charge of microcapsules by ionic cross-linking. Effects of butanol during alkali treatment and citrate in post alkali treatment were monitored in terms of morphology and the chemical properties of microcapsules. Various characterization techniques revealed that the aggregation was decreased and surface roughness was increased with layer formation.

The continued atherosclerotic risk in rheumatoid arthritis (RA) has been inadequately explained by conventional factors. Chronic inflammation and endothelial activation seems responsible for developing insulin resistance (IR). The study was aimed to assess the role of inflammation and endothelial activation causing IR in long term RA patients leading to increased atherosclerotic risk. Fifty (25 long-duration and 25 short-duration) RA patients and twenty-three healthy controls were recruited excluding potential confounding co-morbidities. Fasting insulin, proinflammatory cytokines, endothelial stress markers and adipokines were quantified by ELISA. Homeostasis Model Assessment (HOMA)-IR calculated using glucose and insulin values. Atherosclerotic indices were measured using ultrasound. Lipid profile was comparable among groups. Mean carotid intima media thickness (cIMT) was significantly higher in both RA groups (p = 0.0062) compared to controls. HOMA-IR was significantly higher in long-duration RA (p = 0.005); it showed significant associations with DAS 28 (p = 0.01) and hsCRP (p = 0.03) in this subset. Mean cIMT for short-duration RA (p = 0.02) and long-duration RA (p = 0.0006) respectively was also significantly associated with HOMA-IR. Pro-inflammatory markers like TNF-α, resistin and leptin were highest in long-duration RA, higher in short-duration RA when compared to control group respectively. HOMA-IR was significantly dependent on TNF-α (p = 0.008), resistin (p = 0.031), leptin (p = 0.0054). Mean cIMT showed association with all parameters mainly with TNF-α (p = 0.001), iNOS (p = 0.001), resistin (p = 0.008) and leptin (p = 0.04). Persistent inflammation leads to altered adipokine secretion promoting IR in RA patients with long disease duration. Treatment with conventional disease modifying anti-rheumatic drugs (DMARDs) is incomplete to control chronic inflammation and limit progression of atherosclerosis.

Some of thermo-responsive polysaccharides, namely, cellulose, xyloglucan, and chitosan, and protein-like gelatin or elastin-like polypeptides can exhibit temperature dependent sol–gel transitions. Due to their biodegradability, biocompatibility, and non-toxicity, such biomaterials are becoming popular for drug delivery and tissue engineering applications. This paper aims to review the properties of sol–gel transition, mechanical strength, drug release (bioavailability of drugs), and cytotoxicity of stimuli-responsive hydrogel made of thermo-responsive biopolymers in drug delivery systems. One of the major applications of such thermos-responsive biopolymers is on textile-based transdermal therapy where the formulation, mechanical, and drug release properties and the cytotoxicity of thermo-responsive hydrogel in drug delivery systems of traditional Chinese medicine have been fully reviewed. Textile-based transdermal therapy, a non-invasive method to treat skin-related disease, can overcome the poor bioavailability of drugs from conventional non-invasive administration. This study also discusses the future prospects of stimuli-responsive hydrogels made of thermo-responsive biopolymers for non-invasive treatment of skin-related disease via textile-based transdermal therapy.