Ribozyme-based approaches have been extensively employed for in vitro circular RNA (circRNA) synthesis. However, several critical challenges are impeding the progress in this field, including the relatively low ribozyme utilization efficiency, limited synthetic flexibility, and complicated downstream purification procedures. Here, we introduce a split intron-exon (SIE) system for circRNA synthesis by physically separating the ribozyme from its substrates. This design ensures efficient circRNA synthesis by overcoming the inherent limitations of current ribozyme-based techniques, in which each ribozyme can only catalyse the synthesis of at most one circRNA molecule. Moreover, the SIE system enables the efficient synthesis of both unmodified and chemically modified circRNAs. Furthermore, the recyclability and immobilization of the ribozyme within the SIE system reduce reaction impurities and improves circRNA enrichment and yield. Overall, the SIE system holds great potential to advance the diversification and large-scale development of circRNA therapeutics. Current ribozyme-based methods enable efficient circular RNA synthesis but suffer from inflexibility. Here, the authors introduce the split intron-exon (SIE) system, which separates ribozymes from substrates to facilitate the efficient production of modified circular RNAs, optimizing production process.
Lei Wang, Qiaoli Zhai, Chunbo Dong et al.· Nature Communications· 0 citations
Myocardial infarction (MI) remains a major challenge in clinical practice, as the irreversible loss of cardiomyocytes and the limited repair capacity of the adult heart constrain cardiac repair. Traditional cell therapy once held great promise, but its clinical application has been constrained by issues such as low cell survival, immune rejection and procedural complexity. Against this background, extracellular vesicles (EVs) have attracted attention as a paracrine delivery strategy. By delivering bioactive cargo, including proteins, nucleic acids and lipids, EVs mediate intercellular communication and thereby support cardiac repair. This review focuses on the clinical potential of EVs, comparing the advantages, limitations and safety risks of EVs from different cellular origins, and places particular emphasis on engineered delivery strategies aimed at improving targeting, retention and therapeutic efficacy. In parallel, we examine the core barriers to clinical translation, including large scale manufacturing challenges, batch to batch consistency, storage stability, and regulatory and ethical issues; it is these barriers, rather than insufficient efficacy, that constitute the key bottleneck to the clinical application of EVs. Compared with existing reviews, this review, by emphasizing a clinical translation perspective, systematically analyzes the key issues facing EV-based therapeutic strategies in their progression from experimental research to clinical application, providing a practical theoretical framework for EV-based myocardial repair therapies and clarifying the prospects for EVs in the treatment of MI.
Kaiyi Zhu, Jing Bai, Liangfu Xu et al.· Journal of Controlled Releas...· 0 citations