Smart Strategies for Precise Delivery of CRISPR/Cas9 in Genome Editing.

The emergence of CRISPR/Cas technology has enabled scientists to precisely edit genomic DNA sequences. This approach can be used to modulate gene expression for the treatment of genetic disorders and incurable diseases such as cancer. This potent genome-editing tool is based on a single guide RNA (sgRNA) strand that recognizes the targeted DNA, plus a Cas nuclease protein for binding and processing the target. CRISPR/Cas has great potential for editing many genes in different types of cells and organisms both in vitro and in vivo. Despite these remarkable advances, the risk of off-target effects has hindered the translation of CRISPR/Cas technology into clinical applications. To overcome this hurdle, researchers have devised gene regulatory systems that can be controlled in a spatiotemporal manner, by designing special sgRNA, Cas, and CRISPR/Cas delivery vehicles that are responsive to different stimuli, such as temperature, light, magnetic fields, ultrasound (US), pH, redox, and enzymatic activity. These systems can even respond to dual or multiple stimuli simultaneously, thereby providing superior spatial and temporal control over CRISPR/Cas gene editing. Herein, we summarize the latest advances on smart sgRNA, Cas, and CRISPR/Cas nanocarriers, categorized according to their stimulus type (physical, chemical, or biological).

Alginate scaffolds improve functional recovery after spinal cord injury.

PURPOSE: In this systematic review and meta-analysis, the use of alginate for the repair of the damaged spinal cord was investigated. METHODS: After an extensive search of databases including MEDLINE, SCOPUS, EMBASE and Web of Science, an initial screening was performed based on inclusion and exclusion criteria. The full text of related articles was reviewed and data mining was performed. Data were analyzed by calculating the mean of ratios between treated and untreated groups using STATA software. Subgroup analysis was also performed due to heterogeneity. Articles were subjected to quality control and PRISMA guidelines were followed. RESULTS: Twelve studies and 17 experiments were included in the study. After SCI, alginate hydrogel had a moderate effect on motor function recovery (SMD = 0.64; 95% CI 0.28-1.00; p < 0.0001) and alginate scaffolds loaded with drugs, growth factors, or cells on the SCI group compared with untreated SCI animals showed has a strong effect in the treatment of SCI (SMD = 2.82; 95% CI 1.49-4.145; p < 0.0001). Treatment with drug/cell in combination with alginate was more strongly significant compared to the groups treated with drug/cell alone (SMD = 4.55; 95% CI 1.42-7.69; p < 0.0001). Alginate alone or in combination therapy when used as an implant, had a more significant effect than injection. CONCLUSION: These findings suggest that alginate is an efficient scaffold for functional recovery and even a much better scaffold for drug/cell delivery after SCI.