Engineering stimuli-responsive nanocarriers for CRISPR/Cas9 genome editing: next-generation cancer therapeutics

OBJECTIVES: To highlight recent developments in CRISPR/Cas9 genome-editing strategies for cancer therapy and to evaluate how nanocarrier-based delivery systems enable controlled, spatiotemporal manipulation of genetic information to overcome off-target effects, cytotoxicity, and limitations in clinical translation. KEY FINDINGS: CRISPR/Cas9 has emerged as a simple and programmable tool for correcting cancer-associated mutations and regulating adaptive immune responses; however, challenges such as off-target effects, unintended mutations in healthy cells, and cytotoxicity hinder its clinical application. Nanocarriers address these limitations through refined spatiotemporal delivery of Cas9 nuclease and sgRNA using internal and external stimuli-responsive functional groups. These systems improve cancer-cell specificity by engineering guide RNAs, prevent premature clearance, enhance systemic circulation and intracellular delivery, enable nuclear targeting, and regulate Cas9 activity. Stimuli such as light, heat, ultrasound, magnetic fields, pH, redox conditions, glutathione, and oxygen play key roles in controlled activation and release. SUMMARY: This review critically evaluates the structural design of nanocarriers, advanced spatiotemporal regulation strategies, and safety and efficacy concerns in CRISPR/Cas9-based cancer therapeutics. It discusses the role of cell-specific promoters, small-molecule stimulation, and stimuli-responsive delivery systems in improving genome-editing precision and therapeutic outcomes. The review also outlines future opportunities for exploiting CRISPR/Cas9 in advanced biomedical applications to enhance the effectiveness of next-generation cancer therapy.