Human germline editing: Insights to future clinical treatment of diseases

[Some present and future ethical dilemmas surrounding advancements in in vitro fertilization.]

The growing field of assisted human reproduction has achieved unimaginable milestones. Its continuous development and the innovations it generates at times pose both ethical and legal dilemmas. This essay aims to elucidate the progressive changes occurring in the realm of the origin of life due to the development of new options and strategies in assisted human reproduction. First, it constructs an interdisciplinary reflection on human nature and the changes society faces from the perspectives of science, ethics, and law, particularly from the perspective of Spain. Second, it provides a brief overview of current or future biomedical techniques in the field of human reproduction. It concludes with a discussion of the need to reflect on the rapid advancement of science in assisted human reproduction.

[Development of CRISPR technology and its application in bone and cartilage tissue engineering]

The CRISPR/Cas9 system, consisting of Cas9 nuclease and single guide RNA (sgRNA), is an emerging gene editing technology that can perform gene reprogramming operations such as deletion, insertion, and point mutation on DNA sequences targeted by sgRNA. In addition, CRISPR/dCas9 (a mutant that loses Cas9 nuclease activity) still retains the ability of sgRNA to target DNA. The fusion of dCas9 protein with transcriptional activator (CRISPRa) can activate the expression of the target gene, and fusion transcriptional repressors (CRISPRi) can also be used to suppress target gene expression. Efficient delivery of the CRISPR/Cas9 system is one of the main problems limiting its wide clinical application. Viral vectors are widely used to efficiently deliver CRISPR/Cas9 elements, but non-viral vector research is more attractive in terms of safety, simplicity, and flexibility. In this review, we summarize the principles and research advances of CRISPR technology, including CRISPR/ Cas9 delivery vectors, delivery methods, and obstacles to the delivery, and review the progress of CRISPR-based research in bone and cartilage tissue engineering. Finally, the challenges and future applications of CRISPR technology in bone and cartilage tissue engineering are discussed.