mRNA therapeutics: Molecular mechanisms, delivery platforms, regulatory frameworks, and equitable global access.

Messenger RNA (mRNA) therapeutics represent a transformative pharmaceutical modality, with three products approved by 2024 across infectious disease and rare metabolic indications. This review critically examines: (i) mRNA molecular architecture including nucleoside modification strategies for immune evasion and platforms beyond conventional mRNA (self-amplifying RNA [saRNA], circular RNA); (ii) lipid nanoparticle (LNP) delivery mechanisms encompassing endosomal escape limitations, selective organ targeting (SORT), and emerging alternative delivery systems including single-component carriers; (iii) the clinical application landscape spanning vaccines, personalised cancer immunotherapy, protein replacement, and CRISPR genome editing; (iv) translational challenges including stability, tissue-targeting, immunogenicity, and manufacturing scalability; and (v) the critically underrepresented dimensions of regulatory science and equitable global access in low- and middle-income countries (LMICs), drawing on Indonesia's BPOM as a policy case study contextualised within the broader LMIC regulatory landscape. Concrete capacity-building recommendations - including establishment of regional mRNA reference standard laboratories, low-cost dsRNA analytical platforms, and harmonised pharmacovigilance systems - are proposed. This review provides a molecularly grounded and policy-relevant synthesis for drug delivery scientists and regulators advancing equitable mRNA therapeutic access.