Therapeutic gene editing: delivery and regulatory perspectives

Abstract

Gene-editing technology is an emerging therapeutic modality for manipulating the eukaryotic genome by using target-sequence-specific engineered nucleases. Because of the exceptional advantages that gene-editing technology offers in facilitating the accurate correction of sequences in a genome, gene editing-based therapy is being aggressively developed as a next-generation therapeutic approach to treat a wide range of diseases. However, strategies for precise engineering and delivery of gene-editing nucleases, including zinc finger nucleases, transcription activator-like effector nuclease, and CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats-associated nuclease Cas9), present major obstacles to the development of gene-editing therapies, as with other gene-targeting therapeutics. Currently, viral and non-viral vectors are being studied for the delivery of these nucleases into cells in the form of DNA, mRNA, or proteins. Clinical trials are already ongoing, and in vivo studies are actively investigating the applicability of CRISPR/Cas9 techniques. However, the concept of correcting the genome poses major concerns from a regulatory perspective, especially in terms of safety. This review addresses current research trends and delivery strategies for gene editing-based therapeutics in non-clinical and clinical settings and considers the associated regulatory issues.

Immunity to CRISPR Cas9 and Cas12a therapeutics

“…These strategies generally build on judicial gRNA and target selection, Cas9 protein engineering, and controlled expression of CRISPR‐Cas9 components, as illustrated in recent reviews . Next is the pursuit of targeted delivery and expression of Cas9 and Cas12a in desired cell types and tissues, which can be achieved through the use of many viral and nonviral means …”

Manipulation of the human tRNA pool reveals distinct tRNA sets that act in cellular proliferation or cell cycle arrest

“…Such selective essentiality is important as it may suggest that targeting these tRNAs in a mixture of healthy and cancerous cells may affect mainly cancer. It is worth mentioning in that respect the continuous improvement in precise delivery and activation of CRISPR technology in-vivo (Shim et al 2017;Tong et al 2019), such development increase the prospects of manipulation of specific tRNAs in a target within the body.…”

Niosome-Based Approach for In Situ Gene Delivery to Retina and Brain Cortex as Immune-Privileged Tissues

“…In any case, non-viral vectors for plasmid-based gene therapy have not yet reached clinical practice, although research on this topic has quickly increased during the last few years, which has been especially motivated by the impact that CRISPR/Cas technology has had on scientific community and the need to deliver such genetic material in a safe and efficient way to target cells. In this sense, at a preclinical level, non-viral vectors for CRISPR/Cas delivery predominate over the use of viral vectors (70% versus 30%, respectively) [44]. Among non-viral gene delivery systems, we can differentiate the development of physical and chemical methods.…”