The increasing prevalence of infectious diseases in recent decades has posed a serious threat to public health. Routes of transmission differ, but the respiratory droplet or airborne route has the greatest potential to disrupt social intercourse, while being amenable to prevention by the humble face mask. Different types of masks give different levels of protection to the user. The ongoing COVID-19 pandemic has even resulted in a global shortage of face masks and the raw materials that go into them, driving individuals to self-produce masks from household items. At the same time, research has been accelerated towards improving the quality and performance of face masks, e.g., by introducing properties such as antimicrobial activity and superhydrophobicity. This review will cover mask-wearing from the public health perspective, the technical details of commercial and home-made masks, and recent advances in mask engineering, disinfection, and materials and discuss the sustainability of mask-wearing and mask production into the future.

In situ gel delivery systems are preferred over conventional systems due to sustained and prolonged release action of therapeutic payload onto the targeted site. Thermogel, a form of in situ gel-forming polymeric formulation, undergoes sol–gel transition after administration into the body. At room temperature, the system is an aqueous polymer solution that easily entraps therapeutic payload by mixing. Upon injection, the higher physiological temperature causes gelation in situ because of the presence of thermosensitive polymers. The gel degrades gradually over time, allowing sustained release of therapeutics localized to the site of interest. This minimizes systemic toxicity and improved efficacy of drug release to the targeted site. Thermogel properties can be easily altered for specific applications via substitution and modification of components in diblock and triblock copolymer systems. The feasibility of fine-tuning allows modifications to biodegradability, biocompatibility, biological functionalization, mechanical properties, and drug release profile. This review summarized recent development in thermogel research with a focus on synthesis and self-assembly mechanisms, gel biodegradability, and applications for drug delivery, cell encapsulation and tissue engineering. This review also assessed inadequacy of material properties as a stand-alone factor on therapeutic action efficacy in human trials, with a focus on OncoGel, an experimental thermogel that demonstrated excellent individual or synergistic drug delivery system in preclinical trials but lacked therapeutic impact in human trials. Detailed analysis from all aspects must be considered during technology development for a successful thermogel platform in drug delivery and tissue engineering.

Temporarily implanted devices, such as drug-loaded contact lenses, are emerging as the preferred treatment method for ocular diseases like glaucoma. Localizing the delivery of glaucoma drugs, such as timolol maleate (TM), can minimize adverse effects caused by systemic administration. Although eye drops and drug-soaked lenses allow for local treatment, their utility is limited by burst release and a lack of sustained therapeutic delivery. Additionally, wet transportation and storage of drug-soaked lenses result in drug loss due to elution from the lenses. Here we present a nanodiamond (ND)-embedded contact lens capable of lysozyme-triggered release of TM for sustained therapy. We find that ND-embedded lenses composed of enzyme-cleavable polymers allow for controlled and sustained release of TM in the presence of lysozyme. Retention of drug activity is verified in primary human trabecular meshwork cells. These results demonstrate the translational potential of an ND-embedded lens capable of drug sequestration and enzyme activation.