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.
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 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.
Microfluidics, a toolbox comprising methods for precise manipulation of fluids at small length scales (micrometers to millimeters), has become useful for manipulating cells. Its uses range from dynamic management of cellular interactions to high-throughput screening of cells, and to precise analysis of chemical contents in single cells. Microfluidics demonstrates a completely new perspective and an excellent practical way to manipulate cells for solving various needs in biology and medicine. This review introduces and comments on recent achievements and challenges of using microfluidics to manipulate and analyze cells. It is believed that microfluidics will assume an even greater role in the mechanistic understanding of cell biology and, eventually, in clinical applications.
This report shows that a nanovector composed of peptide-based nanofibrous hydrogel can condense DNA to result in strong immune responses against HIV. This nanovector can strongly activate both humoral and cellular immune responses to a balanced level rarely reported in previous studies, which is crucial for HIV prevention and therapy. In addition, this nanovector shows good biosafety in vitro and in vivo. Detailed characterizations show that the nanofibrous structure of the hydrogel is critical for the dramatically improved immune responses compared to existing materials. This peptide-based nanofibrous hydrogel shows great potential for efficacious HIV DNA vaccines and can be potentially used for delivering other vaccines and drugs.
Skin wounds on stretchable parts of the body including the elbows, knees, wrists, and nape usually undergo delayed and poor healing due to the interference of their frequent motion. Ordinary dressings that are not flexible enough face difficulty to promote wound healing due to the mismatching between the mechanics of the dressing materials and the wounds. In this study, an injectable, biocompatible, self‐healable, and conductive material poly(3,4‐ethylenedioxythiophene): poly(styrenesulfonate)/guar slime (PPGS) is developed for healing wounds with various kinds of movements. As a proof‐of‐principle assay, the healing effect of PPGS is explored on a skin wound model on the nape of rats that often experiences frequent movements. PPGS, which can be prepared within 1 min, successfully accelerates the healing of the wounds. The results suggest that PPGS has great potential in the fields of tissue engineering and biomedicine.
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 Pololike kinase 1 (PLK-1) protein and suppression of the tumor growth (467%) 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.
This microfluidic flow-stretch chip integrates fluid shear stress (FSS) and cyclic stretch (CS), two major mechanical stimulations in cardiovascular systems, for cultured cells. The model chip can deliver FSS and CS simultaneously or independently to vascular cells to mimic the haemodynamic microenvironment of blood vessels in vivo. By imposing FSS-only, CS-only, and FSS+CS stimulation on rat mesenchymal stem cells and human umbilical vein endothelial cells, we found the alignment of the cellular stress fibers varied with cell type and the type of stimulation. The flow-stretch chip is a reliable tool for simulating the haemodynamic microenvironment.
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