The steep road to nonviral nanomedicines: Frequent challenges and culprits in designing nanoparticles for gene therapy

The potential of therapeutically loaded nanoparticles (NPs) has been successfully demonstrated during the last decade, with NP-mediated nonviral gene delivery gathering significant attention as highlighted by the broad clinical acceptance of mRNA-based COVID-19 vaccines. A significant barrier to progress in this emerging area is the wild variability of approaches reported in published literature regarding nanoparticle characterizations. Here, we provide a brief overview of the current status and outline im-portant concerns regarding the need for standardized protocols to evaluate NP uptake, NP transfection efficacy, drug dose determi-nation, and variability of nonviral gene delivery systems. Based on these concerns, we propose wide adherence to multimodal, multiparameter, and multistudy analysis of NP systems. Adoption of these proposed approaches will ensure improved transparency, provide a better basis for interlaboratory comparisons, and will simplify judging the significance of new findings in a broader context, all critical requirements for advancing the field of nonviral gene delivery.

Automated summary

Over the past decade, the potential of therapeutically loaded nanoparticles (NPs) has been successfully demonstrated, particularly in the field of nonviral gene delivery, as highlighted by the clinical acceptance of mRNA-based COVID-19 vaccines. However, a major challenge in this emerging area is the lack of standardization in nanoparticle characterizations. In this article, we provide an overview of the current status and highlight the need for standardized protocols to evaluate NP uptake, NP transfection efficacy, drug dose determination, and variability of nonviral gene delivery systems. We propose the adoption of multimodal, multiparameter, and multistudy analysis of NP systems to improve transparency, enable interlaboratory comparisons, and facilitate the advancement of nonviral gene delivery.