Nanocarrier-mediated CRISPR-Cas delivery: a novel approach against antibiotic-resistant superbugs

Antibiotic resistance (ABR) is a leading cause of death and a major public health threat globally. Without appropriate interventions, annual ABR-associated deaths have been projected to reach 10 million by 2050 worldwide. Hence, it is critical to develop novel therapeutic interventions that would be able to tackle ABR by targeting mainly the pathogenic microbes, while lessening harm to beneficial microbes. There is an increasing research interest in CRISPR-Cas (CC) systems owing to their potential in controlling and preventing horizontal gene transfer and spread of antibiotic resistance. In addition, CC systems offer several advantages, including high efficiency, rapid turnaround time, low cost, and easy design, which allow these systems to effectively and precisely target antibiotic-resistant bacteria. CRISPR-based gene therapy offers numerous benefits; however, the major limitation in clinical translation is the safe and effective delivery of CRISPR components to target organs or cells, thus hindering its potential in therapeutic interventions. Nanocarriers (NCs) can help the CC systems to overcome their off-target effects by precisely delivering the systems to the target cells. NCs can also be engineered for target site release, payload protection, and high specificity, which can further ensure delivery of the components of CC in the target cells or regions without harming surrounding tissues. This review summarizes the principles and mechanisms of CC systems, highlights their applications against antibiotic-resistant bacteria, and discusses emerging nanocarrier-based delivery strategies that may enhance the clinical utility of CRISPR-Cas technologies in managing ABR.