Construction of GSH-responsive polyethyleneimine-based delivery vector for effective gene transfection.

The rise of gene therapy has solved many diseases that cannot be effectively treated by conventional methods. Gene vectors is very important to protect and deliver the therapeutic genes to the target site. Polyethyleneimine (PEI) modified with mannitol could enhance the gene transfection efficiency reported by our group previously. In order to further control and improve the effective gene release to action site, disulfide bonds were introduced into mannitol-modified PEI to construct new non-viral gene vectors PeiSM. The degrees of mannitol linking with disulfide bonds were screened. Among them, moderate mannitol-modified PEI with disulfide bonds showed the best transfection efficiency, and significantly enhanced long-term systemic transgene expression for 72 hin vivoeven at a single dose administration, and could promote caveolae-mediated uptake through up-regulating the phosphorylation of caveolin-1 and increase the loaded gene release from the nanocomplexes in high glutathione intracellular environment. This functionalized gene delivery system can be used as an potential and safe non-viral nanovector for further gene therapy.

Polymer-Initiating Caveolae-Mediated Endocytosis and GSH-Responsive MiR-34a Gene Delivery System for Enhanced Orthotopic Triple Negative Breast Cancer Therapy.

Gene therapy based on miRNAs has broad application prospects in the treatment of tumors. However, due to degradation and ineffective release during intracellular transport, current gene delivery vectors used for miRNAs limited their actual transfection efficiency. This study develops a novel nonviral vector PEI-SPDP-Man (PSM) that can simultaneously target cellular uptake pathways and intracellular responsive release for miR-34a. PSM is synthesized by connected mannitol (Man) to branched polyethylenimine (PEI) using a disulfide bond. The prepared PSM/miR-34a gene delivery system can induce and enter to tumor cells through caveolae-mediated endocytosis to reduce the degradation of miR-34a in lysosomes. The disulfide bond is sensed at high concentration of glutathione (GSH) in the tumor cells and miR-34a is released, thereby reducing the expression of Bcl-2 and CD44 to suppress the proliferation and invasion of tumor cells. In vitro and in vivo experiments show that through the targeted cellular uptake and the efficient release of miR-34a, an effective antitumor and antimetastasis profiles for the treatment of orthotopic triple negative breast cancer (TNBC) are achieved. This strategy of controlling intracellular transport pathways by targeting cellular uptake pathways in the gene therapy is an approach that could be developed for highly effective cancer therapy.

Case report: mitochondrial diabetes mellitus in a Chinese family due to m.3243A>G.

OBJECTIVES: Mitochondrial diabetes mellitus is caused by dysfunctional mitochondria and is often misdiagnosed because of its various clinical manifestations. It's even rarer in children, and without a clear family history of diabetes with hearing loss, it's often difficult to diagnose. CASE PRESENTATION: This is a case study of a family with maternally inherited diabetes mellitus and deafness (MIDD). The proband was an adolescent girl with diabetes with a family history of type 2 diabetes (T2DM) for three generations. Family members have undetected hearing impaired. The proband could not be diagnosed with type 1 diabetes (T1DM) or T2DM. Therefore, whole exome and mitochondrial gene sequencing was performed, which identified an m.3243A>G mutation in the mitochondrial DNA. CONCLUSIONS: This suggests that we should be alert to the possibility of hereditary diabetes, especially mitochondrial diabetes in patients with atypical diabetes. A thorough physical examination is very important. What is new: (1) Mitochondrial diabetes in childhood may not be accompanied by deafness even with highly heteroplasmy levels. (2) In MIDD patients, sometimes hearing loss cannot be perceived, which requires us to conduct detailed physical examinations and related examinations. (3) The use of metformin in MIDD patients did not have adverse consequences.

Construction of mPEI/pGPX4 gene therapeutic system for the effective treatment of acute lung injury.

Acute lung injury (ALI) can be induced by various injury factors, which is closely related to the inflammatory reaction and cellular ferroptosis reported recently. Glutathione peroxidase (GPX4) palys an important role in the inflammatory reaction, which also is the core regulatory protein of ferroptosis. Up-regulation of GPX4 can be helpful to inhibit the cellular ferroptosis and inflammatory reaction to treat ALI. mPEI/pGPX4 gene therapeutic system based on mannitol-modified polyethyleneimine (mPEI) was constructed. Compared with PEI/pGPX4 nanoparticles using commoditized gene vector PEI 25k, mPEI/pGPX4 nanoparticles achieved caveolae-mediated endocytosis and improved the gene therapeutic effect. mPEI/pGPX4 nanoparticles could up-regulate the gene expression of GPX4, inhibit inflammatory reaction and the cellular ferroptosis, thereby alleviating the ALIin vitroandin vivo. The finding indicated that gene therapy with pGPX4 is a potential therapeutic system for the effective treatment of ALI.

Tumor targeted combination therapeutic system for the effective treatment of drug resistant triple negative breast cancer.

Breast cancer has become the malignant tumor with the largest incidence, especially the drug resistant triple negative breast cancer (TNBC). The combination therapeutic system can play a better role in resisting drug resistant TNBC. In this study, dopamine and tumor targeted folic acid modified dopamine were synthesized as carrier materials to construct melanin-like tumor targeted combination therapeutic system. The optimized nanoparticles of CPT/Fe@PDA-FA10 with efficient loading of camptothecin and iron was achieved, which showed tumor targeted delivery ability, pH sensitive controlled release, effective photothermal conversion performance and excellent anti-tumor efficacy in vitro and in vivo. CPT/Fe@PDA-FA10 plus laser could significantly kill the drug resistant tumor cells, inhibit the growth of the orthotopic drug resistant triple negative breast cancer through apoptosis/ferroptosis/photothermal treatment, and had no significant side effects on the main tissues and organs. This strategy provided a new idea for the construction and clinical application of triple-combination therapeutic system as effective treatment for drug resistant triple negative breast cancer.

Bone targeted miRNA delivery system for miR-34a with enhanced anti-tumor efficacy to bone-associated metastatic breast cancer.

Bone metastatic cancer is the most common occurrence in breast cancer, and the treatment is also facing great challenges. MicroRNA-34a (miRNA-34a) is a promising anti-cancer miRNA for gene therapy to bone metastatic cancer patients. However, the lack of specificity to bone and low accumulation at the site of bone tumor remains the major challenge when used bone-associated tumor. To solve this problem, a bone-targeted vector for delivery of miR-34a to bone metastatic breast cancer was constructed by using the commonly used gene vector branched polyethylenimine 25 k (BPEI 25 k) as the skeleton and linking with alendronate (ALN) moieties for bone targeting group. The constructed gene delivery system PCA/miR-34a can efficiently prevent miR-34a from degradation during blood circulation and enhance the specific bone delivery and distribution. PCA/miR-34a nanoparticles can be uptake into tumor cells through clathrin and caveolae-mediated endocytosis, and directly regulate the expression of oncogenes, thus promoting tumor cell apoptosis and relieving bone tissue erosion. The results of experiments in vitro and in vivo confirmed that the constructed bone-targeted miRNA delivery system PCA/miR-34a can enhance the anti-tumor efficacy in bone metastatic cancer, and provide a potential strategy for gene therapy in bone metastatic cancer.

Vitamin E D-alpha-tocopheryl polyethylene glycol 1000 succinate-conjugated liposomal docetaxel reverses multidrug resistance in breast cancer cells.

OBJECTIVES: Multidrug resistance (MDR) remains a primary challenge in breast cancer treatment. In the present study, D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS)-coated docetaxel-loaded liposomes were developed as a novel drug delivery system to reverse MDR and enhance breast cancer therapy compared with the traditional liposomes, DSPE-mPEG-coated liposomes (stealth liposomes) and commercial Taxotere® . KEY FINDINGS: Liposomes were prepared by thin - film dispersion method. Evaluations were performed using human breast cancer MCF-7 and resistant MCF-7/ADR cells. The reversal multidrug-resistant effect was assessed by P-gp inhibition assay, cytotoxicity, cellular uptake and apoptosis assay. RESULTS: The TPGS-chol-liposomes were of an appropriate particle size (140.0 ± 6.0 nm), zeta potential (-0.196 ± 0.08 mv), high encapsulation efficiency (99.0 ± 0.9) and favourable in vitro sustained release. The TPGS-coated liposomes significantly improved cytotoxicity and increased the intracellular accumulation of docetaxel in both types of breast cancer cells. The TPGS-coated liposomes were confirmed to induce apoptosis via a synergistic effect between docetaxel and TPGS. It was demonstrated that TPGS enhanced the intracellular accumulation of drug by inhibiting overexpressed P-glycoprotein. CONCLUSIONS: The TPGS-conjugated liposomes showed significant advantages in vitro compared with the PEG-conjugated liposomes. The TPGS-conjugated liposomes could reverse the MDR and enhance breast cancer therapy.

Hydrogen Bonding as a Supramolecular Tool for Robust OFET Devices.

In the present study, we demonstrated the effect of hydrogen bonding in the semiconducting behaviour of a small molecule used in organic field-effect transistors (OFETs). For this study, the highly soluble dumbbell-shaped molecule, Boc-TATDPP based on a Boc-protected thiophene-diketopyrrolopyrrole (DPP) and triazatruxene (TAT) moieties was used. The two Boc groups of the molecule were removed by annealing at 200 °C, which created a strong hydrogen-bonded network of NH-TATDPP supported by additional π-π stacking. These were characterised by thermogravimetric analysis (TGA), UV/Vis and IR spectroscopy, XRD and high-resolution (HR)-TEM measurements. FETs were fabricated with the semiconducting channel made of Boc-TATDPP and NH-TATDPP separately. It is worth mentioning that the Boc-TATDPP film can be cast from solution and then annealed to get the other systems with NH-TATDPP. More importantly, NH-TATDPP showed significantly higher hole mobilities compared to Boc-TATDPP. Interestingly, the high hole mobility in the case of NH-TATDPP was unaffected upon blending with [6,6]-phenyl-C71-butyric acid methyl ester (PC71 BM). Thus, this robust hydrogen-bonded supramolecular network is likely to be useful in designing efficient and stable organic optoelectronic devices.