P3HT:Bebq2-Based Photovoltaic Device Enhances Differentiation of hiPSC-Derived Retinal Ganglion Cells.

Electric field stimulation is known to affect various cellular processes, including cell fate specification and differentiation, particularly towards neuronal lineages. This makes it a promising therapeutic strategy to stimulate regeneration of neuronal tissues. Retinal ganglion cells (RGCs) is a type of neural cells of the retina responsible for transduction of visual signals from the retina to the brain cortex, and is often degenerated in various blindness-causing retinal diseases. The organic photovoltaic materials such as poly-3-hexylthiophene (P3HT) can generate electric current upon illumination with light of the visible spectrum, and possesses several advantageous properties, including light weight, flexibility and high biocompatibility, which makes them a highly promising tool for electric stimulation of cells in vitro and in vivo. In this study, we tested the ability to generate photocurrent by several formulations of blend (bulk heterojunction) of P3HT (which is electron donor material) with several electron acceptor materials, including Alq3 and bis(10-hydroxybenzo[h]quinolinato)beryllium (Bebq2). We found that the photovoltaic device based on bulk heterojunction of P3HT with Bebq2 could generate photocurrent when illuminated by both green laser and visible spectrum light. We tested the growth and differentiation capacity of human induced pluripotent stem cells (hiPSC)-derived RGCs when grown in interface with such photostimulated device, and found that they were significantly increased. The application of P3HT:Bebq2-formulation of photovoltaic device has a great potential for developments in retinal transplantation, nerve repair and tissue engineering approaches of treatment of retinal degeneration.

The Clinical Benefits of Antiresorptive Agents in Patients with Primary Breast Cancer Receiving Adjuvant Endocrine Therapy: A Systematic Review with Pairwise and Network Meta-analysis.

CONTEXT: Clinical trials have investigated the role of antiresorptive agents, including bisphosphonates and denosumab, in patients with primary breast cancer receiving adjuvant endocrine therapy, aiming for better bone protection and/or improving survival. OBJECTIVE: To summarize the clinical effects of antiresorptive agents in patients with early breast cancer receiving endocrine therapy. METHODS: We systematically reviewed and synthesized the clinical benefits and harms of antiresorptive agents in patients with early breast cancer receiving endocrine therapy by calculating the risk ratios (RRs). RESULTS: In the pooled meta-analysis, antiresorptive agents had significant clinical benefits on disease recurrence (RR 0.78, 95% CI 0.67-0.90) and locoregional recurrence (RR 0.69, 95% CI 0.49-0.95) in patients with breast cancer receiving endocrine therapy. Early use of antiresorptive agents has a beneficial effect on secondary endocrine therapy resistance instead of primary resistance. Safety analysis revealed that potential risk for osteonecrosis of the jaw (ONJ, RR 3.29, 95% CI 1.12-9.68) with antiresorptive agents; however, there is an insignificant difference in arthralgia. The subgroup analyses revealed that intervention with bisphosphonates might have profound clinical benefits, but also increased the occurrence of ONJ. A network meta-analysis further supported the clinical effects of early antiresorptive agent use compared with delayed use or placebo. CONCLUSION: Using antiresorptive agents early in patients with breast cancer receiving adjuvant endocrine therapy may provide additional benefits in risk reduction of recurrence, but there is a potential risk of ONJ.

Nanomedicine-based Curcumin Approach Improved ROS Damage in Best Dystrophy-specific Induced Pluripotent Stem Cells.

Best dystrophy (BD), also termed best vitelliform macular dystrophy (BVMD), is a juvenile-onset form of macular degeneration and can cause central visual loss. Unfortunately, there is no clear definite therapy for BD or improving the visual function on this progressive disease. The human induced pluripotent stem cell (iPSC) system has been recently applied as an effective tool for genetic consultation and chemical drug screening. In this study, we developed patient-specific induced pluripotent stem cells (BD-iPSCs) from BD patient-derived dental pulp stromal cells and then differentiated BD-iPSCs into retinal pigment epithelial cells (BD-RPEs). BD-RPEs were used as an expandable platform for in vitro candidate drug screening. Compared with unaffected sibling-derived iPSC-derived RPE cells (Ctrl-RPEs), BD-RPEs exhibited typical RPE-specific markers with a lower expression of the tight junction protein ZO-1 and Bestrophin-1 (BEST1), as well as reduced phagocytic capabilities. Notably, among all candidate drugs, curcumin was the most effective for upregulating both the BEST1 and ZO-1 genes in BD-RPEs. Using the iPSC-based drug-screening platform, we further found that curcumin can significantly improve the mRNA expression levels of Best gene in BD-iPSC-derived RPEs. Importantly, we demonstrated that curcumin-loaded PLGA nanoparticles (Cur-NPs) were efficiently internalized by BD-RPEs. The Cur-NPs-based controlled release formulation further increased the expression of ZO-1 and Bestrophin-1, and promoted the function of phagocytosis and voltage-dependent calcium channels in BD-iPSC-derived RPEs. We further demonstrated that Cur-NPs enhanced the expression of antioxidant enzymes with a decrease in intracellular ROS production and hydrogen peroxide-induced oxidative stress. Collectively, these data supported that Cur-NPs provide a potential cytoprotective effect by regulating the anti-oxidative abilities of degenerated RPEs. In addition, the application of patient-specific iPSCs provides an effective platform for drug screening and personalized medicine in incurable diseases.

Promoting Induced Pluripotent Stem Cell-driven Biomineralization and Periodontal Regeneration in Rats with Maxillary-Molar Defects using Injectable BMP-6 Hydrogel.

Periodontal disease may cause considerable destruction of alveolar bone, periodontal ligaments (PDLs) and cementum and even lead to progressive oral dysfunction. Periodontal tissue regeneration is the ultimate goal of periodontal disease treatment to reconstruct both structures and functions. However, the regenerative efficiency is low, possibly due to the lack of a proper periodontal microenvironment. In this study, we applied an injectable and thermosensitive chitosan/gelatin/glycerol phosphate hydrogel to provide a 3D environment for transplanted stem cells and to enhance stem cell delivery and engraftment. The iPSCs-BMP-6-hydrogel complex promoted osteogenesis and the differentiation of new connective tissue and PDL formation. In animal models of maxillary-molar defects, the iPSCs-BMP-6-hydrogel-treated group showed significant mineralization with increased bone volume, trabecular number and trabecular thickness. Synergistic effects of iPSCs and BMP-6 increased both bone and cementum formation. IPSCs-BMP-6-hydrogel-treated animals showed new bone synthesis (increased ALP- and TRAP-positive cells), new PDL regeneration (shown through Masson's trichrome staining and a qualification assay), and reduced levels of inflammatory cytokines. These findings suggest that hydrogel-encapsulated iPSCs combined with BMP-6 provide a new strategy to enhance periodontal regeneration. This combination not only promoted stem cell-derived graft engraftment but also minimized the progress of inflammation, which resulted in highly possible periodontal regeneration.

Synergistic effects of carboxymethyl-hexanoyl chitosan, cationic polyurethane-short branch PEI in miR122 gene delivery: accelerated differentiation of iPSCs into mature hepatocyte-like cells and improved stem cell therapy in a hepatic failure model.

MicroRNA122 (miR122), a liver-specific microRNA, plays critical roles in homeostatic regulation and hepatic-specific differentiation. Induced pluripotent stem cells (iPSCs) have promising potential in regenerative medicine, but it remains unknown whether non-viral vector-mediated miR122 delivery can enhance the differentiation of iPSCs into hepatocyte-like cells (iPSC-Heps) and rescue thioacetamide-induced acute hepatic failure (AHF) in vivo. In this study, we demonstrated that embedment of miR122 complexed with polyurethane-graft-short-branch polyethylenimine copolymer (PU-PEI) in nanostructured amphiphatic carboxymethyl-hexanoyl chitosan (CHC) led to dramatically enhanced miR122 delivery into human dental pulp-derived iPSCs (DP-iPSCs) and facilitated these DP-iPSCs to differentiate into iPSC-Heps (miR122-iPSC-Heps) with mature hepatocyte functions. Microarray and bioinformatics analysis further indicated that CHC/PU-PEI-miR122 promoted the gene-signature pattern of DP-iPSCs to shift into a liver-specific pattern. Furthermore, intrahepatic delivery of miR122-iPSC-Heps, but not miR-Scr-iPSC-Heps, improved liver functions and rescued recipient survival, and CHC-mediated delivery showed a better efficacy than that using phosphate buffered saline as a delivery vehicle. In addition, these transplanted miR122-iPSC-Heps remained viable and could produce circulatory albumin for 4 months. Taken together, our findings demonstrate that non-viral delivery of miR122 shortens the time of iPSC differentiation into hepatocytes and the delivery of miR122-iPSC-Heps using CHC as a vehicle exhibited promising hepatoprotective efficacy in vivo. miR122-iPSC-Heps may represent a feasible cell source and provide an efficient and alternative strategy for hepatic regeneration in AHF.

Nuclear Localization Signal-Enhanced Polyurethane-Short Branch Polyethylenimine-Mediated Delivery of Let-7a Inhibited Cancer Stem-Like Properties by Targeting the 3'-UTR of HMGA2 in Anaplastic Astrocytoma.

Anaplastic astrocytoma (AA) is a grade III glioma that often occurs in middle-aged patients and presents a uniformly poor prognosis. A small subpopulation of cancer stem cells (CSCs) possessing a self-renewing capacity is reported to be responsible for tumor recurrence and therapeutic resistance. An accumulating amount of microRNAs (miRNA) were found aberrantly expressed in human cancers and regulate CSCs. Efforts have been made to couple miRNAs with nonviral gene delivery approaches to target specific genes in cancer cells. However, the efficiency of delivery of miRNAs to AA-derived CSCs is still an applicability hurdle. The present study aimed to investigate the effectiveness and applicability of nonviral vector-mediated delivery of Let-7a with regard to eradication of AA and AA-derived CSC cells. Herein, our miRNA/mRNA microarray and RT-PCR analysis showed that the expression of Let-7a, a tumor-suppressive miRNA, is inversely correlated with the levels of HMGA2 and Sox2 in the AA side population (SP(+)) cells. Luciferase reporter assay showed that Let-7a directly targets the 3'-UTRs of HMGA2 in AA-SP(+) cells. Knockdown of HMGA2 significantly suppressed the protein expression of Sox2 in AA-SP(+) cells, whereas overexpression of HMGA2 upregulated Sox2 expression in AA-SP(-). Nuclear localization signal (NLS) peptides can facilitate nuclear targeting of DNA and are used to improve gene delivery. Using polyurethane-short branch polyethylenimine (PU-PEI) as a therapeutic delivery vehicle, we conjugated NLS with Let-7 and successfully delivered it to AA-SP(+) cells, resulting in significantly suppressed expression of HMGA2 and Sox2, tumorigenicity, and CSC-like abilities. This treatment facilitated the differentiation of AA-SP(+) cells into non-SP CSCs. Furthermore, PU-PEI-mediated delivery of NLS-conjugated Let-7a in AA-SP(+) cells suppressed the expression of drug-resistant and antiapoptotic genes, and increased cell sensitivity to radiation. Finally, the in vivo delivery of PU-PEI-NLS-Let-7a significantly suppressed the tumorigenesis of AA-SP(+) cells and synergistically improved the survival rate of orthotopically AA-SP(+)-transplanted immunocompromised mice when combined with radiotherapy. Therefore, PU-PEI-NLS-Let-7a is a potential novel therapeutic approach for AA.

Enhanced antioxidant capacity of dental pulp-derived iPSC-differentiated hepatocytes and liver regeneration by injectable HGF-releasing hydrogel in fulminant hepatic failure.

Acute hepatic failure (AHF) is a severe liver injury leading to sustained damage and complications. Induced pluripotent stem cells (iPSCs) may be an alternative option for the treatment of AHF. In this study, we reprogrammed human dental pulp-derived fibroblasts into iPSCs, which exhibited pluripotency and the capacity to differentiate into tridermal lineages, including hepatocyte-like cells (iPSC-Heps). These iPSC-Heps resembled human embryonic stem cell-derived hepatocyte-like cells in gene signature and hepatic markers/functions. To improve iPSC-Heps engraftment, we next developed an injectable carboxymethyl-hexanoyl chitosan hydrogel (CHC) with sustained hepatocyte growth factor (HGF) release (HGF-CHC) and investigated the hepatoprotective activity of HGF-CHC-delivered iPSC-Heps in vitro and in an immunocompromised AHF mouse model induced by thioacetamide (TAA). Intrahepatic delivery of HGF-CHC-iPSC-Heps reduced the TAA-induced hepatic necrotic area and rescued liver function and recipient viability. Compared with PBS-delivered iPSC-Heps, the HGF-CHC-delivered iPSC-Heps exhibited higher antioxidant and antiapoptotic activities that reduced hepatic necrotic area. Importantly, these HGF-CHC-mediated responses could be abolished by administering anti-HGF neutralizing antibodies. In conclusion, our findings demonstrated that HGF mediated the enhancement of iPSC-Hep antioxidant/antiapoptotic capacities and hepatoprotection and that HGF-CHC is as an excellent vehicle for iPSC-Hep engraftment in iPSC-based therapy against AHF.

Induction of dental pulp-derived induced pluripotent stem cells in the absence of c-Myc for differentiation into neuron-like cells.

BACKGROUND: A recent research breakthrough has demonstrated that the ectopic expression of four genes is sufficient to reprogram human fibroblasts into inducible pluripotent stem cells (iPSCs). However, whether human dental pulp cells (DPCs) could be reprogrammed into iPSCs remains an open question. In this study, we demonstrated that DPCs from deciduous and permanent teeth can be reprogrammed into iPSCs without c-Myc and had the capacity to differentiate into neuron-like cells. METHODS: DPCs were obtained from donors and reprogrammed into iPSCs using retroviral transduction with SOX2, OCT4, and KLF4. Then, these iPSCs were differentiated into neuron-like cells. Microarray and bioinformatics were used to compare the gene expression profile among these iPSCs and iPSC-derived neuron-like cells. RESULTS: The DPCs displayed a high vitality and capability to quickly restart proliferation and expressed elevated pluripotency similar to mesenchymal stem cells. According to our results, DPC-derived iPSC colonies that could be subcultured and propagated were established as early as 10 days after transduction, in comparison with the skin fibroblast (DPC-derived iPSCs) without c-Myc presented embryonic stem cell-like properties and the pluripotent potential to differentiate into neuron-like cells, which resemble neurons both morphologically and functionally. CONCLUSION: The human DPCs from deciduous and permanent teeth can undergo reprogramming to establish pluripotent stem cell lines without c-Myc. These surgical residues, usually regarded as medical waste, can be used as an alternative source of pluripotent stem cells for personalized medicine.

Inhibition of cancer stem cell-like properties and reduced chemoradioresistance of glioblastoma using microRNA145 with cationic polyurethane-short branch PEI.

Glioblastomas (GBMs) are the most common primary brain tumors with poor prognosis. CD133 has been considered a putative marker of cancer stem cells (CSCs) in malignant cancers, including GBMs. MicroRNAs (miRNAs), highly conserved small RNA molecules, may target oncogenes and have potential as a therapeutic strategy against cancer. However, the role of miRNAs in GBM-associated CSCs remains mostly unclear. In this study, our miRNA/mRNA-microarray and RT-PCR analysis showed that the expression of miR145 (a tumor-suppressive miRNA) is inversely correlated with the levels of Oct4 and Sox2 in GBM-CD133(+) cells and malignant glioma specimens. We demonstrated that miR145 negatively regulates GBM tumorigenesis by targeting Oct4 and Sox2 in GBM-CD133(+). Using polyurethane-short branch polyethylenimine (PU-PEI) as a therapeutic-delivery vehicle, PU-PEI-mediated miR145 delivery to GBM-CD133(+) significantly inhibited their tumorigenic and CSC-like abilities and facilitated their differentiation into CD133(-)-non-CSCs. Furthermore, PU-PEI-miR145-treated GBM-CD133(+) effectively suppressed the expression of drug-resistance and anti-apoptotic genes and increased the sensitivity of the cells to radiation and temozolomide. Finally, the in vivo delivery of PU-PEI-miR145 alone significantly suppressed tumorigenesis with stemness, and synergistically improved the survival rate when used in combination with radiotherapy and temozolomide in orthotopic GBM-CD133(+)-transplanted immunocompromised mice. Therefore, PU-PEI-miR145 is a novel therapeutic approach for malignant brain tumors.

Delivery of Oct4 and SirT1 with cationic polyurethanes-short branch PEI to aged retinal pigment epithelium.

Cationic polyurethane, a biodegradable non-viral vector, protects DNA from nuclease degradation and helps to deliver genes efficiently. Oct4, a POU-domain transcription factor, is highly expressed in maintaining pluripotency and cellular reprogramming process in stem cells. SirT1, a NAD-dependent histone deacetylase, is an essential mediator of cellular longevity. Herein we demonstrated that both Oct4 and SirT1 (Oct4/SirT1) expression was decreased in an age-dependent manner in retina with aged-related macular degeneration and retinal pigment epithelium cells (RPEs). To investigate the possible rescuing role of Oct4/SirT1, polyurethane-short branch polyethylenimine (PU-PEI) was used to deliver Oct4/SirT1 into aged RPEs (aRPEs) or light-injured rat retinas. Oct4/SirT1 overexpression increased the expression of several progenitor-related genes and the self-renewal ability of aRPEs. Moreover, Oct4/SirT1 overexpression resulted in the demethylation of the Oct4 promoter and enhanced the expression of antioxidant enzymes, which was accompanied by a decrease in intracellular ROS production and hydrogen peroxide-induced oxidative stress. Importantly, PU-PEI-mediated Oct4/SirT1 gene transfer rescued retinal cell loss and improved electroretinographic responses in light-injured rat retinas. In summary, these data suggest that PU-PEI-mediated delivery of Oct4/SirT1 reprograms aRPEs into a more primitive state and results in cytoprotection by regulating the antioxidative capabilities of these cells.