Integration of blue light with near-infrared irradiation accelerates the osteogenic differentiation of human dental pulp stem cells.

Blue light is used less in photobiomodulation than red or near-infrared light because of concerns about its high energy. However, some reports have suggested that blue light releases NO from nitrosated proteins, affects cell signal regulation, and promotes stem cell differentiation. Because blue and red lights could have different mechanisms of action, their combination is expected to have new consequences. In this study, human dental pulp stem cells (hDPSCs) were sequentially exposed to blue and near-infrared light to study their effects on proliferation, osteogenic differentiation, and immunomodulation. We found that NIR irradiation applied after blue light can reduce blue light toxicity improving the cell viabiltiy. Delayed luminescence and transmission electron microscopy studies showed that this combination excited hDPSCs and activated mitochondrial biogenesis. Those modulations accelerated hDPSC differentiation, as shown by an increase of about 1.3-fold in alkaline phosphatase activity in vitro and an about 1.5-fold increase in the osteocalcin-positive regions in cells implanted in nude mice compared with mice exposed to near-infrared alone.

SHMT1 siRNA-Loaded hyperosmotic nanochains for blood-brain/tumor barrier post-transmigration therapy.

The near-perivascular accumulation in solid tumors and short-lived span in circulation, derails even the most competent nanoparticles (NPs) from achieving their maximum therapeutic potential. Moreover, delivering them across the blood brain/tumor barrier (BBB/BTB) is further challenging to sought anticancer effect. To address these key challenges, we designed a linearly aligned nucleic acid-complexed polydixylitol-based polymeric nanochains (X-NCs), with inherent hyperosmotic properties enabling transmigration of the BBB/BTB and navigation through deeper regions of the brain tumor. The high aspect ratio adds shape-dependent functional aspects to parent particles by providing effective payload increment and nuclear factor of activated T cells-5 (NFAT5)-mediated cellular uptake. Therefore, serine hydroxymethyltransferase 1 (SHMT1) siRNA-loaded nanochains not only demonstrated to transmigrate the BTB, but also resulted in remarkably reducing the tumor size to 97% in the glioblastoma xenograft brain tumor mouse models. Our study illustrates how the hyperosmotic nanochains with high aspect ratio and aligned structure can accelerate a therapeutic effect in aggressive brain tumors post-transmigration of the BBB/BTB by utilizing an NFAT5 mode of uptake mechanism.

Epidermal Growth Factor-Releasing Radially Aligned Electrospun Nanofibrous Patches for the Regeneration of Chronic Tympanic Membrane Perforations.

Chronic tympanic membrane (TM) perforations can cause otorrhea. To date, various types of tissue engineering techniques have been applied for the regeneration of chronic TM perforations. However, the application of nanofibers with radially aligned nanostructures and the simultaneous release of growth factors have never been applied in the regeneration of chronic TM perforations. Here, epidermal growth factor (EGF)-releasing radially aligned nanofibrous patches (ERA-NFPs) are developed and applied for the regeneration of chronic perforated TMs. First, radial alignments and the presence of EGF in the ERA-NFPs are analyzed. EGF is confirmed to be released from the ERA-NFPs until 8 weeks. In an in vitro study, cell viability assay, immunocytochemistry, and wound-healing assay indicate rational enhancement of healing by the combination of radial alignments and EGF release. The effect of ERA-NFPs on TM cells is revealed by quantitative real-time polymerase chain reaction. An in vivo animal study shows that the ERA-NFPs effectively stimulates the healing of the chronic TM perforations. The TMs healed by ERA-NFPs show histological properties similar to those of normal TMs. These results indicate that ERA-NFPs may be an efficient platform for the regeneration of chronic TM perforations, laying the foundation for nonsurgical treatments of chronic otitis media.

Chitosan/PEI patch releasing EGF and the EGFR gene for the regeneration of the tympanic membrane after perforation.

Damage to the eardrum causes acute pain and can lead to chronic otitis media if it develops into chronic tympanic membrane (TM) perforations. Chronic TM perforations are usually treated with surgical methods such as tympanoplasty and myringoplasty. However, these surgeries are not only complicated and difficult but also cost a lot of money. Our research team developed chitosan patches (E-CPs) that release epidermal growth factor (EGF) as a patch therapy to replace surgical methods. However, there was a limitation in the healing ratio of the treatment compared to the surgical methods. In this study, we developed EGF and epidermal growth factor receptor (EGFR) gene-releasing polyethyleneimine (PEI)/chitosan patches (EErP-CPs) to increase the regeneration of TM perforations. The addition of PEI increased the adhesion and migration ability of TM cells on the patches. The simultaneous release of the EGF and the EGFR gene further enhanced TM cell proliferation, adhesion and migratory ability. It was confirmed that the EGF protein and EGFR gene were released for 30 days; however, EGF was released and increased TM cell viability almost immediately after treatment and EGFR took a minimum of 3 days before showing its effect on improved cell viability. It was also shown that EErP-CPs are more hydrophilic and have more positive charge than E-CP because of added amine groups from PEI. In conclusion, the developed EErP-CPs resulted in the improved healing of TM perforations and can potentially be applied to the regeneration of both chronic and acute tympanic membrane perforations.

Development of a bio-electrospray system for cell and non-viral gene delivery.

Bio-electrospray technology is a very attractive tool for preparing scaffolds and depositing desired solutions on various targets by electric force. In this study, we focused on the application of a bio-electrospray (BES) technique to spray cells on the target and to simultaneously deliver genetic constructs into the cells, called non-viral gene delivery-based bio-electrospray (NVG-BES). Using this method, we tried to harvest the electric charge produced during electrospray for the cellular internalization of cationic polymer/DNA nanoparticles as well as the delivery of living cells on the desired substrate. Furthermore, we optimized the voltage, culture medium and polymeric cationic charges for high transfection efficiency and cell viability during NVG-BES. As a result, the solutions used during the NVG-BES process played an important role in improving transfection efficiency. We determined that a voltage of 10 kV with PBS as the spraying solution showed high transfection efficiency, probably due to the facilitation of cationic polymer/DNA nanocomplexes in cellular internalization and their subsequent expression. In conclusion, NVG-BES, as a novel method, is expected to deliver genes to cells and simultaneously deliver transfected cells to any substrate or scaffold.

Correction: Development of a bio-electrospray system for cell and non-viral gene delivery.

[This corrects the article DOI: 10.1039/C7RA12477E.].

Parthenolide Sensitizes Human Colorectal Cancer Cells to Tumor Necrosis Factor-related Apoptosis-inducing Ligand through Mitochondrial and Caspase Dependent Pathway.

BACKGROUND/AIMS: Combination therapy utilizing tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) in conjunction with other anticancer agents, is a promising strategy to overcome TRAIL resistance in malignant cells. Recently, parthenolide (PT) has proved to be a promising anticancer agent, and several studies have explored its use in combination therapy. Here, we investigated the molecular mechanisms by which PT sensitizes colorectal cancer (CRC) cells to TRAIL-induced apoptosis. METHODS: HT-29 cells (TRAIL-resistant) were treated with PT and/or TRAIL for 24 hours. The inhibitory effect on proliferation was detected using the 3-(4, 5-dimethylthiazol-2yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Annexin V staining, cell cycle analysis, and Hoechst 33258 staining were used to assess apoptotic cell death. Activation of an apoptotic pathway was confirmed by Western blot. RESULTS: Treatment with TRAIL alone inhibited the proliferation of HCT 116 cells in a dose-dependent manner, whereas proliferation was not affected in HT-29 cells. Combination PT and TRAIL treatment significantly inhibited cell growth and induced apoptosis of HT-29 cells. We observed that the synergistic effect was associated with misregulation of B-cell lymphoma 2 (Bcl-2) family members, release of cytochrome C to the cytosol, activation of caspases, and increased levels of p53. CONCLUSION: Combination therapy using PT and TRAIL might offer an effetive strategy to overcome TRAIL resistance in certain CRC cells.

Continuous long-term entecavir therapy in naïve chronic hepatitis B patients showing partial virologic response.

BACKGROUND/AIMS: We investigated the efficacy of continuous long-term entecavir 0.5 mg treatment in naïve chronic hepatitis B patients showing a partial virologic response (PVR). METHODS: A total of 227 patients were included. PVR was defined as a more than 1 log10 IU/mL decline in detectable serum hepatitis B virus (HBV) DNA by polymerase chain reaction (PCR; ≥20 IU/mL) at week 48. A complete virologic response (CVR) was defined as undetectable serum HBV DNA by PCR (<20 IU/mL) at week 48. RESULTS: At week 48, the rate of the PVR was 64/227 (28.2%). Among patients with PVR, the cumulative rates of virologic response (serum HBV DNA <20 IU/mL) at weeks 96 and 144 were 45.2% and 73.8%, respectively. The cumulative rates of genotypic resistance were not significantly different between patients with a PVR and patients with a CVR (p=0.057). However, the cumulative rates of virologic breakthrough were higher in patients with PVR than in patients with CVR (4% vs 0% and 11.2% vs 0% at weeks 96 and 144, respectively; p<0.001). CONCLUSIONS: Long-term continuous entecavir 0.5 mg treatment in patients with a PVR resulted in an additional virologic response without a significant increase in genotypic resistance. However, the rate of virologic breakthrough was higher in the partial responders.