Red Blood Cell-Derived Extracellular Vesicles for Gene and RNA Therapeutics: Biological, Engineering, and Translational Challenges

Gene therapy has great prospects of DNA/RNA manipulations and protein modulations. Its use in clinic is, however, stifled by risks of immunogenicity, low target specificity, and adverse effects. The red blood cell (RBC-EVs) extracellular vesicles can serve as a solution to this issue since they are biocompatible, long-term stable, and with low immunogenicity. RBC-EVs permit the accurate delivery of therapeutic cargo to space and time, thus minimizing systemic toxicity. This review presents the most recent developments on the expansion of the use of RBC-EVs to encapsulate the components of mRNA and CRISPR-Cas. Through the addition of the means to address these deficiencies, including stimulus-sensitive release mechanisms (eg, pH- or light-activated systems) and tissue-selective targeting approaches, RBC-EVs can be applied to enable the precise application in genetic diseases, inflammatory diseases, and cancer. Such innovations have the potential to overcome the clinical need and enable the biological complexity of mRNA- and CRISPR-Cas-based agents to provide a powerful delivery platform. Moreover, the review also demonstrates the unprecedented benefits of red blood cell EVs, which include immune evasion, scalability, and universal loading capacity, which can establish them as the next-generation delivery vehicles. Red blood cell EVs have the potential to increase the efficacy of precision medicine by increasing its feasibility. Lastly, we note the potential and translational issues in the provision of red blood cell EV-based mRNA and CRISPR-Cas therapeutic delivery of gene therapy.