Mijia Zhang

Myocardial infarction (MI) remains a leading cause of death worldwide, yet current therapeutic interventions offer limited capacity for functional cardiac regeneration. In recent years, hydrogels derived from natural products have emerged as compelling therapeutic platforms, attributed to their favorable biocompatibility, tunable biodegradability, and intrinsic biological activities. This review systematically summarizes natural product-derived hydrogels for MI repair, with particular emphasis on representative polysaccharide-based systems, including chitosan, alginate, and hyaluronic acid. It also discusses small-molecule self-assembled hydrogels, such as glycyrrhizic acid, puerarin, and rhein, as well as hydrogel-based extracellular vesicle delivery systems, as complementary therapeutic strategies. We further highlight the multifaceted mechanisms through which these materials ameliorate the pathological cardiac microenvironment, including structural reinforcement, restoration of electrical conduction, modulation of the immune response, promotion of neovascularization, and scavenging of reactive oxygen species. Critical challenges impeding clinical translation, such as long-term biocompatibility, targeted delivery efficiency, and scalable manufacturing, are thoroughly examined, alongside emerging directions including stimuli-responsive systems and three-dimensional bioprinting technologies. Although natural product-derived hydrogels hold considerable promise for cardiac repair, overcoming existing technical hurdles through continued interdisciplinary research remains imperative for their successful transition from bench to bedside.

Depression is a leading global health burden, yet current pharmacotherapy remains constrained by depression‐specific challenges that extend beyond simple blood–brain barrier (BBB) penetration, including delayed onset of action, poor regional brain specificity, and the inability to deliver emerging biologics. Engineered nanomedicine offers a paradigm‐shifting platform to address these limitations through precise designs such as receptor‐mediated transport and cell‐mimetic carriers, enabling targeted modulation of depression‐related neural circuits. This review critically evaluates advanced nanoengineering strategies for antidepressant delivery, distinguishing proof‐of‐concept systems from platforms with realistic translational potential. We further provide a decision‐oriented framework to guide future clinical development. By moving beyond generic strategies for BBB penetration to address the distinctive pharmacotherapeutic shortcomings of depression, engineered nanomedicine holds great promise for advancing next‐generation antidepressant therapies that achieve rapid onset, precise intervention, and comprehensive improvement in patient quality of life.