Inositol based non-viral vectors for transgene expression in human cervical carcinoma and hepatoma cell lines

Targeted GSH-exhausting and hydroxyl radical self-producing manganese-silica nanomissiles for MRI guided ferroptotic cancer therapy

Ferroptosis, a cell death path induced by the generation of reactive oxygen species (ROS), will cause the accumulation of lipid peroxides (PL-PUFA-OOH) and achieve potent tumor-regression. However, glutathione (GSH)-dependent glutathione peroxidase 4 (GPx4) can reduce PL-PUFA-OOH and antagonize the ferroptosis inducing effect of ROS. Herein, folate-PEG modified dihydroartemisinin (DHA) loaded manganese doped mesoporous silica nanoparticles (described as nanomissiles) were constructed for integrating the effect of GSH exhaustion and ROS generation. After endocytosis by tumor cells, intracellular GSH triggered the degradation of nanomissiles, which allowed the simultaneous release of DHA and Fenton catalytic Mn2+ due to the redox reaction between the manganese-oxygen bonds and GSH. The degradation would lead to GSH exhaustion, activation of Mn2+-based magnetic resonance imaging (MRI), and DHA-driven ˙OH generation. The GSH-free environment inhibited the activity of GPx4 and enhanced the accumulation of PL-PUFA-OOH oxidized by ˙OH. Furthermore, the cooperative effects suppressed tumor metastasis by destroying the structure of polyunsaturated fatty acids in the cell membranes and showed potent antitumor activity. This innovative ferroptotic therapy integrating the GSH exhaustion and ROS generation will be a promising strategy for cancer therapy.

Targeted Manganese doped silica nano GSH-cleaner for treatment of Liver Cancer by destroying the intracellular redox homeostasis

Background: Glutathione (GSH), the primary antioxidant in cells, could fight against oxidative stress. Tumor cells display a higher GSH level than normal cells for coping with the hyperoxidative state, which meets the requirements of enhanced metabolism and vicious proliferation. Therefore, the consumption of GSH will lead to cell redox imbalance and impede life activities. Herein, targeted sorafenib (SFB) loaded manganese doped silica nanoparticle (FaPEG-MnMSN@SFB) was constructed, which could destroy the intracellular redox homeostasis by consuming GSH. Methods: In this study, MnMSN was prepared by an optimized one-pot Stober's method for loading SFB, and FaPEG chain was modified on the surface of MnMSN to achieve long circulation and targeted delivery. The anticancer efficacy and mechanism of the designed FaPEG-MnMSN@SFB were assessed both in vitro and in vivo.Results: FaPEG-MnMSN@SFB exhibited efficient antitumor activity by dual depleting intracellular GSH (the degradation of MnMSN would consume intracellular GSH and the SFB would inhibit the effect of Xc- transport system to inhibit GSH synthesis). Moreover, disruption of redox balance would lead to apoptosis and reactive oxygen species (ROS)-dependent ferroptosis of tumor cells. Conclusion: Such a GSH-starvation therapeutic strategy would cause multi-path programmed cell death and could be a promising strategy for cancer therapy.

A novel galactose-PEG-conjugated biodegradable copolymer is an efficient gene delivery vector for immunotherapy of hepatocellular carcinoma

Successful immunogene therapy depends not only on the therapeutic gene but also on the gene delivery vector. In this study, we synthesized a novel copolymer consisting of low-molecular-weight polyethylenimine (PEI) cross-linked by myo-inositol (INO) and conjugated with a galactose-grafted PEG chain, named LA-PegPI. We characterized the chemical structure and molecular weight of the copolymer and particle properties of LA-PegPI/pDNA. Furthermore, we showed that LA-PegPI/pDNA polyplexes possessed excellent stability in physiological salt solution, low cytotoxicity, and high transfection efficiency in the asialoglycoprotein receptor (ASGPR)-positive liver cells in vitro. Importantly, we also showed that through intraperitoneal injection of LA-PegPI/pDNA nanoparticles, the reporter gene was forcefully expressed in the liver hepatocytes of mice. Finally, we documented that intraperitoneal injection of LA-PegPI/pIL15 nanoparticles effectively suppressed tumor growth and prolonged survival time of tumor-bearing mice via activation of CD8⁺ T cells and NK cells and upregulation of the cytokines IFN-γ, TNF, and IL12 in an orthotopic hepatocellular carcinoma mouse model. Interestingly, LA-PegPI/pluc nanoparticles could effectively stimulate the proliferation of NK cells and inhibit tumor growth in this model. In summary, LA-PegPI is a useful gene vector for immunogene therapy of hepatocellular carcinoma, and its potential for clinical application warrants further study.

Properties and applications of nanoparticle/microparticle conveyors with adjuvant characteristics suitable for oral vaccination

Vaccination is one of the most effective approaches in the prevention and control of disease worldwide. Oral vaccination could have wide applications if effective protection cannot be achieved through traditional (eg, parenteral) routes of vaccination. However, oral administration is hampered by the difficulties in transferring vaccines in vivo. This has led to the development of materials such as carriers with potential adjuvant effects. Considering the requirements for selecting adjuvants for oral vaccines as well as the advantages of nanoparticle/microparticle materials as immune effectors and antigen conveyors, synthetic materials could improve the efficiency of oral vaccination. In this review, nanoparticles and microparticles with adjuvant characteristics are described with regard to their potential importance for oral immunization, and some promising and successful modification strategies are summarized.

Chemical Synthesis, Versatile Structures and Functions of Tailorable Adjuvants for Optimizing Oral Vaccination

Oral vaccines have become a recent focus because of their potential significance in disease prevention and therapy. In the development of oral vaccine-based therapeutics, synthetic materials with tailorable structures and versatile functions can act as antigen conveyers with adjuvant effects, reduce the time cost for vaccine optimization, and provide high security and enhanced immunity. This review presents an overview of the current status of tailoring synthetic adjuvants for oral vaccination, modification strategies for producing effectors with specific structures and functions, enhancement of immune-associated efficiencies, including the barrier-crossing capability to protect antigens in the gastrointestinal tract, coordination of the antigens penetrating mucosa and cell barriers, targeting of concentrated antigens to immune-associated cells, and direct stimulation of immune cells. Finally, we focus on prospective synthetic adjuvants that facilitate the use of oral vaccines via two approaches, namely, in vivo antigen expression and cancer immunotherapy.

A Tumor-specific MicroRNA Recognition System Facilitates the Accurate Targeting to Tumor Cells by Magnetic Nanoparticles

Targeted therapy for cancer is a research area of great interest, and magnetic nanoparticles (MNPs) show great potential as targeted carriers for therapeutics. One important class of cancer biomarkers is microRNAs (miRNAs), which play a significant role in tumor initiation and progression. In this study, a cascade recognition system containing multiple plasmids, including a Tet activator, a lacI repressor gene driven by the TetOn promoter, and a reporter gene repressed by the lacI repressor and influenced by multiple endogenous miRNAs, was used to recognize cells that display miRNA signals that are characteristic of cancer. For this purpose, three types of signal miRNAs with high proliferation and metastasis abilities were chosen (miR-21, miR-145, and miR-9). The response of this system to the human breast cancer MCF-7 cell line was 3.2-fold higher than that to the human breast epithelial HBL100 cell line and almost 7.5-fold higher than that to human embryonic kidney HEK293T cells. In combination with polyethyleneimine-modified MNPs, this recognition system targeted the tumor location in situ in an animal model, and an ~42% repression of tumor growth was achieved. Our study provides a new combination of magnetic nanocarrier and gene therapy based on miRNAs that are active in vivo, which has potential for use in future cancer therapies.

Polyetherimide-grafted Fe₃O₄@SiO2₂ nanoparticles as theranostic agents for simultaneous VEGF siRNA delivery and magnetic resonance cell imaging

Engineering a safe and high-efficiency delivery system for efficient RNA interference is critical for successful gene therapy. In this study, we designed a novel nanocarrier system of polyethyleneimine (PEI)-modified Fe₃O₄@SiO₂, which allows high efficient loading of VEGF small hairpin (sh)RNA to form Fe₃O₄@SiO₂/PEI/VEGF shRNA nanocomposites for VEGF gene silencing as well as magnetic resonance (MR) imaging. The size, morphology, particle stability, magnetic properties, and gene-binding capacity and protection were determined. Low cytotoxicity and hemolyticity against human red blood cells showed the excellent biocompatibility of the multifunctional nanocomposites, and also no significant coagulation was observed. The nanocomposites maintain their superparamagnetic property at room temperature and no appreciable change in magnetism, even after PEI modification. The qualitative and quantitative analysis of cellular internalization into MCF-7 human breast cancer cells by Prussian blue staining and inductively coupled plasma atomic emission spectroscopy analysis, respectively, demonstrated that the Fe₃O₄@SiO₂/PEI/VEGF shRNA nanocomposites could be easily internalized by MCF-7 cells, and they exhibited significant inhibition of VEGF gene expression. Furthermore, the MR cellular images showed that the superparamagnetic iron oxide core of our Fe₃O₄@SiO₂/PEI/VEGF shRNA nanocomposites could also act as a T₂-weighted contrast agent for cancer MR imaging. Our data highlight multifunctional Fe₃O₄@SiO₂/PEI/VEGF shRNA nanocomposites as a potential platform for simultaneous gene delivery and MR cell imaging, which are promising as theranostic agents for cancer treatment and diagnosis in the future.

Using inositol as a biocompatible ligand for efficient transgene expression

Transgene transfection techniques using cationic polymers such as polyethylenimines (PEIs) and PEI derivatives as gene vectors have shown efficacy, although they also have shortcomings. PEIs have decent DNA-binding capability and good cell internalization performance, but they cannot deliver gene payloads very efficiently to cell nuclei. In this study, three hyperbranched polyglycerol-polyethylenimine (PG6-PEI) polymers conjugated with myo-inositol (INO) molecules were developed. The three resulting PG6-PEI-INO polymers have an increased number of INO ligands per molecule. PG6-PEI-INO 1 had only 14 carboxymethyl INO (CMINO) units per molecule. PG6-PEI-INO 2 had approximately 130 CMINO units per molecule. PG6-PEI-INO 3 had as high as 415 CMINO units approximately. Mixing PG6-PEI-INO polymers with DNA produced compact nanocomposites. We then performed localization studies using fluorescent microscopy. As the number of conjugated inositol ligands increased in PG6-PEI-INO polymers, there was a corresponding increase in accumulation of the polymers within 293T cell nuclei. Transfection performed with spherical 293T cells yielded 82% of EGFP-positive cells when using PG6-PEI-INO 3 as the vehicle. Studies further revealed that extracellular adenosine triphosphate (eATP) can inhibit the transgene efficiency of PG6-PEI-INO polymers, as compared with PEI and PG6-PEI that were not conjugated with inositol. Our work unveiled the possibility of using inositol as an effective ligand for transgene expression.