Non-viral CRISPR activation system targeting VEGF-A and TGF-ß1 for enhanced osteogenesis of pre-osteoblasts implanted with dual-crosslinked hydrogel.

Healing of large calvarial bone defects remains challenge but may be improved by stimulating bone regeneration of implanted cells. The aim of this study is to specially co-activate transforming growth factor ß1 (TGF-ß1) and vascular endothelial growth factor (VEGF-A) genes expressions in pre-osteoblast MC3T3-E1 cells through the non-viral CRISPR activation (CRISPRa) system to promote osteogenesis. A cationic copolymer carrying nucleus localizing peptides and proton sponge groups dimethyl-histidine was synthesized to deliver CRISPRa system into MC3T3-E1 cells with high cellular uptake, lysosomal escape, and nuclear translocation, which activated VEGF-A and TGF-ß1 genes expressions and thereby additively or synergistically induced several osteogenic genes expressions. A tunable dual-crosslinked hydrogel was developed to implant the above engineered cells into mice calvaria bone defect site to promote bone healing in vivo. The combination of multi-genes activation through non-viral CRISPRa system and tunable dual-crosslinked hydrogel provides a versatile strategy for promoting bone healing with synergistic effect.

A component-optimized chemo-dynamic nanoagent for enhanced tumour cell-selective chemo-dynamic therapy with minimal side effects in a glioma mouse model.

Although CuO-deposited bovine serum albumin (CuO-BSA) and glucose oxidase (GOx) were combined to achieve H2O2 self-supplied chemo-dynamic therapy (CDT) and glucose consumption-based starvation therapy, the uses of copper and GOx have not been optimized to enhance tumour-selective reactive oxygen species (ROS) generation and minimize toxicity to normal cells as well. Here, chemo-dynamic nanoparticles (CBGP NPs) were prepared through a facile biomineralization process and subsequent coatings with GOx and the cationic polymer PEG2k-PEI1.8k. Through optimizing the use of copper, GOx, and PEG2k-PEI1.8k, the CBGP NPs showed high cellular uptake efficiency, enhanced tumour-selective ROS generation, and minimal side effects toward normal cells. The CBGP NP-mediated glucose consumption, GSH-depletion, and ˙OH generation synergistically induced tumour cell apoptosis both in vitro and in vivo. It is believed that the optimized CBGP NPs can be a promising nanoplatform for effective tumour therapy with minimal side effects.