Methotrexate–Mn²⁺ based NCPs with uniform size and easy fabrication exhibited good MRI and excellent antitumor effects as a novel theranostic nanoplatform.

As an endogenous signaling molecule, carbon monoxide (CO) has emerged as an increasingly promising option regarding as gas therapy due to its positive pharmacological effects in various diseases. Owing to the gaseous nature and potential toxicity, it is particularly important to modulate the CO release dosages and targeted locations to elucidate the biological mechanisms of CO and facilitate its clinical applications. Based on these, diverse CO-releasing molecules (CORMs) have been developed for controlled release of CO in biological systems. However, practical applications of these CORMs are limited by several disadvantages including low stability, poor solubility, weak releasing controllability, random diffusion, and potential toxicity. In light of rapid developments and diverse advantages of nanomedicine, abundant nanomaterials releasing CO in controlled ways have been developed for therapeutic purposes across various diseases. Due to their nanoscale sizes, diversified compositions and modified surfaces, vast CO-releasing nanomaterials (CORNMs) have been constructed and exhibited controlled CO release in specific locations under various stimuli with better pharmacokinetics and pharmacodynamics. In this review, we present the recent progress in CORNMs according to their compositions. Following a concise introduction to CO therapy, CORMs and CORNMs, the representative research progress of CORNMs constructed from organic nanostructures, hybrid nanomaterials, inorganic nanomaterials, and nanocomposites is elaborated. The basic properties of these CORNMs, such as active components, CO releasing mechanisms, detection methods, and therapeutic applications, are discussed in detail and listed in a table. Finally, we explore and discuss the prospects and challenges associated with utilizing nanomaterials for biological CO release.

Renal diseases remain a major global health burden, with an estimated 850 million individuals affected by chronic kidney disease, acute kidney injury, glomerulonephritis, and diabetic nephropathy. These multifactorial diseases collectively account for substantial morbidity and mortality burdens. This grim trajectory demands urgent development of drugs that are capable of simultaneously enhancing renal efficacy while circumventing systemic toxicity. In response to this challenge, engineered nanoplatforms designed specifically for the treatment of kidney diseases have emerged as a promising solution. These nanoplatforms offer the unique ability to deliver targeted therapeutics directly to specific regions of the kidney, thereby improving drug efficacy while reducing off-target effects. Unlike the well-established oncological applications of nanomedicine, renal-specific formulations remain in their developmental nascency. Nevertheless, accumulating preclinical evidence indicates that nanotherapeutics hold significant promise for improving the clinical management of kidney diseases through targeted and mechanism-based interventions. The nephrotropic mechanisms and structural determinants of renal nanoplatforms fundamentally diverge from those of conventional nanotherapeutics. Therefore, a thorough understanding of the principles governing renal targeting is essential for designing nanomedicines that achieve precise kidney-specific delivery while ensuring biosafety. In this review, we summarize the current understanding of structure-function relationships that govern the targeting efficiency and biodistribution of nanoparticles in the kidney, with a focus on passive targeting mechanisms driven by key physicochemical parameters, such as particle size, surface charge, shape, and density, as well as active targeting strategies based on specific receptor-ligand interactions.