Lingmin Zhang

CRISPR/Cas9 system is a powerful toolbox for gene editing. However, the low delivery efficiency is still a big hurdle impeding its applications. Herein, we report a strategy to deliver Cas9-sgPlk-1 plasmids (CP) by a multifunctional vehicle for tumor therapy. We condensed CPs on TAT peptide-modified Au nanoparticles (AuNPs/CP, ACP) via electrostatic interactions, and coated lipids (DOTAP, DOPE, cholesterol, PEG2000-DSPE) on the ACP to form lipid-encapsulated, AuNPs-condensed CP (LACP). LACP can enter tumor cells and release CP into the cytosol by laser-triggered thermo-effects of the AuNPs; the CP can enter nuclei by TAT guidance, enabling effective knock-outs of target gene (Plk-1) of tumor (melanoma) and inhibition of the tumor both in vitro and in vivo. This AuNPs-condensed, lipid-encapsulated, and laser-controlled delivery system provides a versatile method for high efficiency CRISPR/Cas9 delivery and targeted gene editing for treatment of a wide spectrum of diseases.

Remedying a multidrug-resistant (MDR) bacteria wound infection is a major challenge due to the inability of conventional antibiotics to treat such infections against MDR bacteria. Thus, developing wound dressings for wound care, particularly against MDR bacteria, is in huge demand. Here, we present a strategy in designing wound dressings: we use a small molecule (6-aminopenicillanic acid, APA)-coated gold nanoparticles (AuNPs) to inhibit MDR bacteria. We dope the AuNPs into electrospun fibers of poly(ε-caprolactone) (PCL)/gelatin to yield materials that guard against wound infection by MDR bacteria. We systematically evaluate the bactericidal activity of the AuNPs and wound-healing capability via the electrospun scaffold. APA-modified AuNPs (Au_APA) exhibit remarkable antibacterial activity even when confronted with MDR bacteria. Meanwhile, Au_APA has outstanding biocompatibility. Moreover, an in vivo bacteria-infected wound-healing experiment indicates that it has a striking ability to remedy a MDR bacteria wound infection. This wound scaffold can assist the wound care for bacterial infections.

Pancreatic cancer is one of the deadliest human cancers, whose progression is highly dependent on the nervous microenvironment. The suppression of gene expression of nerve growth factor (NGF) may have great potential in pancreatic cancer treatment. Here we show that gold nanocluster-assisted delivery of siRNA of NGF (GNC-siRNA) allows efficient NGF gene silencing and pancreatic cancer treatment. The GNC-siRNA complex increases the stability of siRNA in serum, prolongs the circulation lifetime of siRNA in blood and enhances the cellular uptake and tumour accumulation of siRNA. The GNC-siRNA complex potently downregulates the NGF expression in Panc-1 cells and in pancreatic tumours, and effectively inhibits the tumour progression in three pancreatic tumour models (subcutaneous model, orthotopic model and patient-derived xenograft model) without adverse effects. Our study constitutes a straightforward but effective approach to inhibit pancreatic cancer via NGF knockdown, suggesting a promising therapeutic direction for pancreatic cancer.

The emerging CRISPR/Cas9 system represents a promising platform for genome editing. However, its low transfection efficiency is a major problem hampering the application of the gene-editing potential of CRISPR/Cas9. Herein, by screening a pool of more than 56 kinds of agents, we constructed a novel polyethylene glycol phospholipid-modified cationic lipid nanoparticle (PLNP)-based delivery system that can condense and encapsulate a Cas9/single-guide RNA (sgRNA) plasmid (DNA) to form a core–shell structure (PLNP/DNA) that mediated up to 47.4% successful transfection of Cas9/sgPLK-1 plasmids in A375 cells in vitro. An intratumor injection of Cas9/sgPLK-1 plasmids into melanoma tumor-bearing mice resulted in significant downregulation of Polo-like kinase 1 (PLK-1) protein and suppression of the tumor growth (>67%) in vivo. This approach provides a versatile method that could be used for delivering the CRISPR/Cas9 system with high efficiency and safety both in vitro and in vivo. A material for delivering CRISPR–Cas9 to the nuclei of cells has been developed by researchers in China. CRISPR–Cas9 is a powerful gene editing system found in bacteria. Scientists have recently harnessed it to edit genes in mammalian cells and even human embryos, opening the door to a host of revolutionary medical treatments. But the plasmid encoding CRISPR–Cas9 is a large nucleic acid, which limits the efficiency with which it can enter target cells. Now, Xingyu Jiang from the National Center for Nanoscience and Technology, Beijing, and colleagues have demonstrated a versatile method for delivering CRISPR–Cas9 efficiently and safely. After screening more than 56 agents, they constructed polyethylene glycol phospholipid–modified cationic lipid nanoparticles to encapsulate CRISPR–Cas9, which allowed nanoparticles to be delivered to melanoma cells with an efficiency of 47%. Our work contributes to synthesize a vehicle based on lipid nanoparticles, which can effectively deliver Cas9/sgRNA-fused plasmid DNA in vitro and in vivo. This approach mediated successful transfection of Cas9/sgRNA plasmids in multiple cell lines in vitro. The vehicle carrying Cas9/sgRNA targeting PLK-1 resulted in significant down-regulation of PLK-1 protein and suppression of melanoma growth in vivo.

Abstract The type II bacterial clustered, regularly interspaced, short palindromic repeats (CRISPR)‐Cas9 (CRISPR‐associated protein) system (CRISPR‐Cas9) is a powerful toolbox for gene‐editing, however, the nonviral delivery of CRISPR‐Cas9 to cells or tissues remains a key challenge. This paper reports a strategy to deliver Cas9 protein and single guide RNA (sgRNA) plasmid by a nanocarrier with a core of gold nanoclusters (GNs) and a shell of lipids. By modifying the GNs with HIV‐1‐transactivator of transcription peptide, the cargo (Cas9/sgRNA) can be delivered into cell nuclei. This strategy is utilized to treat melanoma by designing sgRNA targeting Polo‐like kinase‐1 ( Plk1 ) of the tumor. The nanoparticle (polyethylene glycol‐lipid/GNs/Cas9 protein/sgPlk1 plasmid, LGCP) leads to >70% down‐regulation of Plk1 protein expression of A375 cells in vitro. Moreover, the LGCP suppresses melanoma progress by 75% on mice. Thus, this strategy can deliver protein‐nucleic acid hybrid agents for gene therapy.