Studying the in vitro behavior of cationic solid lipid nanoparticles as a nonviral vector

Enhanced delivery of CRISPR/Cas9 system based on biomimetic nanoparticles for hepatitis B virus therapy

The persistent presence of covalently closed circular DNA (cccDNA) in hepatocyte nuclei poses a significant obstacle to achieving a comprehensive cure for hepatitis B virus (HBV). Current applications of CRISPR/Cas9 for targeting and eliminating cccDNA have been confined to in vitro studies due to challenges in stable cccDNA expression in animal models and the limited non-immunogenicity of delivery systems. This study addresses these limitations by introducing a novel non-viral gene delivery system utilizing Gemini Surfactant (GS). The developed system creates stable and targeted CRISPR/Cas9 nanodrugs with a negatively charged surface through modification with red blood cell membranes (RBCM) or hepatocyte membranes (HCM), resulting in GS-pDNA@Cas9-CMs complexes. These GS-pDNA complexes demonstrated complete formation at a 4:1 w/w ratio. The in vitro transfection efficiency of GS-pDNA-HCM reached 54.61%, showing homotypic targeting and excellent safety. Additionally, the study identified the most effective single-guide RNA (sgRNA) from six sequences delivered by GS-pDNA@Cas9-HCM. Using GS-pDNA@Cas9-HCM, a significant reduction of 96.47% in in vitro HBV cccDNA and a 52.34% reduction in in vivo HBV cccDNA were observed, along with a notable decrease in other HBV-related markers. The investigation of GS complex uptake by AML-12 cells under varied time and temperature conditions revealed clathrin-mediated endocytosis (CME) for GS-pDNA and caveolin-mediated endocytosis (CVME) for GS-pDNA-HCM and GS-pDNA-RBCM. In summary, this research presents biomimetic gene-editing nanovectors based on GS (GS-pDNA@Cas9-CMs) and explores their precise and targeted clearance of cccDNA using CRISPR/Cas9, demonstrating good biocompatibility both in vitro and in vivo. This innovative approach provides a promising therapeutic strategy for advancing the cure of HBV.

Nanomaterial Exposure Induced Neutrophil Extracellular Traps: A New Target in Inflammation and Innate Immunity

Nanotechnology has become a novel subject with impact in many research and technology areas. Nanoparticles (NPs), as a key component in nanotechnology, are widely used in many areas such as optical, magnetic, electrical, and mechanical engineering. The biomedical and pharmaceutical industries have embraced NPs as a viable drug delivery modality. As such, the potential for NP-induced cytotoxicity has emerged as a major concern for NP drug delivery systems. Thus, it is important to understand how NPs affect the innate immune system. As the most abundant myeloid cell type in innate immune responses, neutrophils are critical for concerns about potentially toxic side effects of NPs. When activated by innate immune stimuli, neutrophils may initiate NETosis to release neutrophil extracellular traps (NETs). Herein, we have reviewed the relationship between NPs and the induction of NETosis and release of NETs.

Tumour microenvironment-responsive lipoic acid nanoparticles for targeted delivery of docetaxel to lung cancer

In the present study, we developed a novel type of reduction-sensitive nanoparticles (NPs) for docetaxel (DTX) delivery based on cross-linked lipoic acid NPs (LANPs). The physicochemical properties, cellular uptake and in vitro cytotoxicity of DTX loaded LANPs (DTX-LANPs) on A549 cells were investigated. Furthermore, the in vivo distribution and in vivo efficacy of DTX-LANPs was evaluated. The results showed that DTX-LANPs had a particle size of 110 nm and a negative zeta potential of −35 mv with excellent colloidal stability. LANPs efficiently encapsulated DTX with a high drug loading of 4.51% ± 0.49% and showed remarkable reduction-sensitive drug release in vitro. Cellular uptake experiments demonstrated that LANPs significantly increased intracellular DTX uptake by about 10 fold as compared with free DTX. The cytotoxicity of DTX-LANPs showed significantly higher potency in inhibiting A549 cell growth than free DTX, while blank LANPs had a good biocompatibility. In addition, in vivo experiments demonstrated that DTX-LANPs could enhance tumour targeting and anti-tumour efficacy with low systemic toxicity. In conclusion, LANPs may prove to be a potential tumour microenvironment-responsive delivery system for cancer treatment, with the potential for commercialization due to the simple component, controllable synthesis, stability and economy.

The impact of cationic solid lipid nanoparticles on human neutrophil activation and formation of neutrophil extracellular traps (NETs)

Cationic solid lipid nanoparticles (cSLNs) are extensively employed as the nanocarriers for drug/gene targeting to tumors and the brain. Investigation into the possible immune response of cSLNs is still lacking. The aim of this study was to evaluate the impact of cSLNs upon the activation of human polymorphonuclear neutrophil cells (PMNs). The cytotoxicity, pro-inflammatory mediators, Ca(2+) mobilization, mitogen-activated protein kinases (MAPKs), and neutrophil extracellular traps (NETs) as the indicators of PMN stimulation were examined in this work. The cSLNs presented a diameter of 195 nm with a zeta potential of 44 mV. The cSLNs could interact with the cell membrane to produce a direct membrane lysis and the subsequent cytotoxicity according to lactate dehydrogenase (LDH) elevation. The interaction of cSLNs with the membrane also triggered a Ca(2+) influx, followed by the induction of oxidative stress and degranulation. The cationic nanoparticles elevated the levels of superoxide anion and elastase by 24- and 9-fold, respectively. The PMN activation by cSLNs promoted the phosphorylation of p38 and Jun-N-terminal kinases (JNK) but not extracellular signal-regulated kinases (ERK). The imaging of scanning electron microscopy (SEM) and immunofluorescence demonstrated the production of NETs by cSLNs. This phenomenon was not significant for the neutral SLNs (nSLNs), although histones in NETs also increased after treatment of nSLNs. Our results suggest an important role of cSLNs in governing the activation of human neutrophils.

Nanotechnology to drive stem cell commitment

Stem cells (SCs) are undifferentiated cells responsible for the growth, homeostasis and repair of many tissues. The maintenance and survival of SCs is strongly influenced by several stimuli from the local microenvironment. The majority of signaling molecules interact with SCs at the nanoscale level. Therefore, scaffolds with surface nanostructures have potential applications for SCs and in the field of regenerative medicine. Although some strategies have already reached the field of cell biology, strategies based on modification at nanoscale level are new players in the fields of SCs and tissue regeneration. The introduction of the possibility to perform such modifications to these fields is probably due to increasing improvements in nanomaterials for biomedical applications, as well as new insights into SC biology. The aim of the present review is to exhibit the most recent applications of nanostructured materials that drive the commitment of adult SCs for potential clinical applications.