Heat Confinement Aerogel Enables Supramagnetothermal Effect for Triggering Nitric Oxide Generation.

Reducing heat dissipation plays an indispensable role in boosting the magnetothermal effect but has received scant attention. Herein, a magnetothermal aerogel (MA) combining an efficient magnetothermal convertor for heat generation and a highly porous aerogel for reducing heat dissipation is developed. Such a heat confinement MA shows a large thermal resistance and high infrared absorption that can effectively confine the heat by regulating interior thermal conduction and radiation, exhibiting a supramagnetothermal effect. In addition, a waterproof beeswax coated MA achieves negligible heat loss and a supramagnetothermal effect even in high-thermal-diffusion aqueous media. As a proof of concept, a synthesized heat-triggered nitric oxide (NO) precursor is integrated into an MA, and the rapid NO generation (∼22 µM/min) resulting in an antibacterial effect further verifies the supramagnetothermal effect of the MA. This work provides an efficient strategy to promote the magnetothermal effect and offers inspiration for building a heat-triggering system.

Metal Graphitic Nanocapsules for Theranostics in Harsh Conditions.

Metal nanoparticles (NPs) with superior physicochemical properties and biocompatibility have shown great potential in theranostics. However, metal NPs show poor stability in some harsh conditions such as strong acid, oxidation, corrosion and high-temperature conditions, which limits their extensive bioapplications. To address such issue, a variety of superstable metal graphitic nanocapsules with the metal cores confined in the nanospace of few-layer graphitic shell have been developed for biodetection and therapy in harsh conditions. In this mini-review, we summarize the recent advances in metal graphitic nanocapsules for bioapplications in harsh conditions. Firstly, their theranostic performance in non-intrinsic physiological harsh environment, including oxidation, corrosion and high-temperature conditions, is systematically discussed. Then, we highlight their theranostic performance in the harsh stomach condition that is strong acidic and pepsin-rich. It is expected that this review will offer inspiration to facilitate the exploitation of novel theranostic agents that are stable in harsh conditions.