Tiny Titans, big promise: Nanotechnology and microRNA in the fight against Alzheimer's disease.

Alzheimer's disease (AD) remains the most common neurodegenerative disorder. It is driven by complex molecular dysfunctions that includes amyloid aggregation, tau pathology, and neuroinflammation. It leads to cognitive deficits and memory loss in elderly people. Current treatments offer limited symptomatic relief. Hence, there is urgent need for innovative therapeutics and diagnostic approaches. Among emerging therapeutic targets, microRNAs (miRNAs) have pivotal role in regulating genes linked to amyloid precursor protein (APP), tau phosphorylation, and inflammatory cascades. This review explores the synergistic as well as individual potentials of nanotechnology and microRNAs (miRNAs) in AD. Nanotechnology aids in targeted drug delivery, enhanced imaging and theranostic capabilities; whereas miRNAs are key regulators of gene expression. Beyond pathogenesis, circulating and cerebrospinal miRNAs serve as minimally invasive biomarkers capable of distinguishing AD from mild cognitive impairment, offering early diagnostic potential. However, therapeutic translation faces challenges of instability, poor bioavailability, and limited blood-brain barrier (BBB) permeability. Here, combination of nanotechnology with miRNA is a compelling solution. Engineered nano-based system enhance miRNA stability, protect them from enzymatic degradation, and enable targeted delivery. This review highlights the synergistic use of nanotechnology and miRNA for AD diagnostics and therapeutics as a multifaceted strategy. Together, these advances promise a path toward early diagnosis and personalized treatment options for AD.