RNA vaccines have emerged as an attractive platform for treating infectious diseases, cancer immunotherapy, and personalized medicine; however, their clinical success depends on multiple factors, including efficient, stable, and scalable delivery systems. Because RNA molecules are highly sensitive to factors such as enzymatic degradation, oxidation, poor cellular uptake, and limited endosomal escape, nanocarrier platforms play essential roles in protecting RNA cargo and enabling effective intracellular delivery. The biological performance of RNA nanocarriers depends on efficient cellular uptake, endosomal escape, intracellular RNA delivery, biodistribution, and immune modulation. Comparative assessment emphasizes that lipid nanoparticles remain the most clinically mature approach, while nanostructured lipid carriers, polymeric systems, and exosome-based nanocarriers provide multiple benefits for stability, targeted delivery, biocompatibility, and/or controlled release. Translational challenges involving GMP manufacturing, batch reproducibility, regulatory expectations, and scale-up are considered critical for effective nano-based RNA vaccine delivery and are elaborated in this review. Emerging advances such as pKa-tuned ionizable lipids, ligand-targeted systems, stimuli-responsive nanocarriers, circular and self-amplifying RNA platforms, artificial intelligence-guided formulation design, and needle-free delivery technologies may further expand the safety, accessibility, and therapeutic potential of RNA vaccines. In this review, we highlight next-generation nanocarrier systems for RNA vaccines, with an emphasis on novel nanocarrier RNA vaccine delivery systems. Additionally, we evaluate stability engineering approaches that currently limit global vaccine distribution and the future of the nanocarrier platforms for RNA vaccines.

Ribonucleic acid-based vaccines have emerged as one of the most significant advances in modern vaccine development, demonstrating remarkable clinical success and enabling rapid responses to emerging infectious diseases. Despite their therapeutic potential, the development of these vaccines remains challenging because of the inherent instability of ribonucleic acid molecules, their susceptibility to degradation, and the complexity of formulation design. Ensuring product quality, stability, and biological performance therefore requires comprehensive analytical characterization throughout development, manufacturing, storage, and quality control. This review provides a comprehensive overview of current analytical strategies used to evaluate ribonucleic acid-based vaccine formulations. Key analytical approaches for assessing molecular integrity, purity, encapsulation efficiency, particle morphology, size distribution, surface characteristics, structural attributes, and biological potency are discussed. The review also examines the influence of formulation composition, lipid nanoparticle design, manufacturing processes, and storage conditions on vaccine stability and performance. In addition, major degradation pathways, critical quality attributes, and analytical challenges associated with quality assessment are highlighted. Furthermore, current regulatory considerations and limitations of existing analytical methodologies are discussed, particularly the challenges associated with establishing robust relationships between physicochemical properties and biological efficacy. The review emphasizes the importance of integrated multi-method analytical approaches for comprehensive characterization and quality assurance. Continued advances in analytical technologies and standardization efforts will be essential for supporting the development of safe, effective, and stable ribonucleic acid-based vaccines and for facilitating their broader pharmaceutical applications.

Chimeric antigen receptor (CAR) T-cell therapy has transformed the treatment of haematological malignancies, but conventional viral transduction results in semi-random genomic integration, contributing to heterogeneous CAR expression and potential insertional effects. Site-specific genome engineering offers an alternative by directing CAR insertion to defined genomic loci, allowing greater control over transgene expression and cellular function. This narrative review evaluates advances in site-specific CAR T-cell engineering, focusing on integration mechanisms, donor platforms, genomic loci, safety, and translational readiness. Homology-directed repair (HDR) and homology-independent targeted integration (HITI) are critically compared alongside viral and non-viral donor systems. Candidate loci are evaluated according to their functional consequences and level of evidence, with TRAC representing the most extensively characterised target, while PDCD1, CD7, CD247, and other loci offer distinct functional opportunities but remain supported by varying levels of preclinical and translational evidence. The review also examines genomic risks associated with targeted editing, including structural rearrangements and chromosome-scale abnormalities, and considers emerging applications in allogeneic, solid-tumour, and in vivo CAR T-cell engineering. Overall, site-specific integration provides a framework for linking CAR placement to therapeutic function, but no single locus or integration strategy is universally optimal. Clinical evidence remains limited relative to the expanding preclinical landscape, and genomic safety, scalable manufacturing, and clinical validation remain major priorities for translation.