Advances in aptamer technology and its updated applications in gastric cancer.

Gastric cancer (GC) is one of the leading causes of cancer-related mortality worldwide, with late-stage diagnosis and limited treatment efficacy. The major challenges in chemotherapy and radiotherapy for GC include drug resistance, systemic toxicity, limited tumor selectivity, adverse side effects, tumor heterogeneity, and the development of radioresistance, all of which hinder treatment efficacy and patient outcomes. Aptamers, single-stranded DNA or RNA molecules with high specificity and affinity for molecular targets, offer a promising alternative to traditional diagnostic and therapeutic approaches. Due to their high specificity and low immunogenicity, aptamers improve non-invasive diagnostic techniques, enabling early GC detection and targeted therapeutic applications. Therapeutically, aptamers facilitate precise drug targeting, reducing systemic toxicity and improving treatment outcomes, especially for drug-resistant and metastatic cases. Integration with nanotechnology further enhances their potential, enabling theranostic applications that combine diagnosis and therapy. Despite these advancements, challenges such as physiological stability, renal clearance, and tissue permeability remain, necessitating further research into chemical modifications and nanocarrier-based delivery systems. This study provides a comprehensive review of recent advancements in aptamer technology and its evolving applications in GC, with a particular emphasis on diagnostic and therapeutic strategies. The first section explores aptamer development strategies, including emerging selection techniques and molecular modifications to enhance their specificity and stability. The subsequent section examines the role of aptamers in GC diagnostics and treatment, with a focus on targeted chemotherapy and immunotherapy. Lastly, we discuss the current challenges in aptamer-based approaches and outline future perspectives for their clinical translation.