Redox-Regulating Black Phosphorus Quantum Dots: Mechanistic Insights, Biomedical Applications, and Ocular Therapeutic Perspectives
Abstract
Black phosphorus quantum dots (BPQDs) have recently emerged as promising two-dimensional nanomaterials with unique physicochemical and biological properties, attracting growing attention in biomedical and ophthalmic nanotechnology. Their size-dependent electronic structure, strong light–matter interactions, and intrinsic biodegradability enable diverse biomedical functionalities ranging from photonic applications to therapeutic and regenerative strategies.Recent experimental studies suggest that BPQDs exhibit pronounced nonlinear optical properties and can enhance radiosensitivity and chemosensitivity in cancer models. In addition, BPQD-based systems have been shown to regulate stem cell–mediated osteogenesis and immune responses, while also demonstrating neuroprotective potential in ocular diseases through modulation of oxidative stress and inhibition of ferroptosis-related pathways. These multifunctional characteristics position BPQDs as promising candidates for advanced ocular drug delivery and therapeutic interventions.Despite these encouraging findings, several critical challenges remain for their biomedical translation. BPQDs exhibit chemical instability under physiological conditions and may induce dose-dependent cytotoxicity associated with oxidative stress, DNA damage, and developmental abnormalities. Such factors highlight the importance of systematic nanotoxicological assessment and careful optimization of physicochemical properties.This review provides an integrated analysis of the intrinsic physicochemical characteristics, engineered functionalization strategies, and emerging biomedical evidence of BPQDs, with particular emphasis on ophthalmic applications and ocular drug delivery. Furthermore, key translational challenges including biosafety concerns, instability, lack of methodological standardization, and limited long-term in vivo evidence are critically examined. Finally, future research directions are proposed to facilitate the rational design and safe clinical development of BPQD-based platforms in ocular nanomedicine.