Corneal repair by human corneal keratocyte-reprogrammed iPSCs and amphiphatic carboxymethyl-hexanoyl chitosan hydrogel.

Induced pluripotent stem cells (iPSCs) have promising potential in regenerative medicine, but whether iPSCs can promote corneal reconstruction remains undetermined. In this study, we successfully reprogrammed human corneal keratocytes into iPSCs. To prevent feeder cell contamination, these iPSCs were cultured onto a serum- and feeder-free system in which they remained stable through 30 passages and showed ESC-like pluripotent property. To investigate the availability of iPSCs as bioengineered substitutes in corneal repair, we developed a thermo-gelling injectable amphiphatic carboxymethyl-hexanoyl chitosan (CHC) nanoscale hydrogel and found that such gel increased the viability and CD44+proportion of iPSCs, and maintained their stem-cell like gene expression, in the presence of culture media. Combined treatment of iPSC with CHC hydrogel (iPSC/CHC hydrogel) facilitated wound healing in surgical abrasion-injured corneas. In severe corneal damage induced by alkaline, iPSC/CHC hydrogel enhanced corneal reconstruction by downregulating oxidative stress and recruiting endogenous epithelial cells to restore corneal epithelial thickness. Therefore, we demonstrated that these human keratocyte-reprogrammed iPSCs, when combined with CHC hydrogel, can be used as a rapid delivery system to efficiently enhance corneal wound healing. In addition, iPSCs reprogrammed from corneal surgical residues may serve as an alternative cell source for personalized therapies for human corneal damage.

Chien Y ，Liao YW ，Liu DM ，Lin HL ，Chen SJ ，Chen HL ，Peng CH ，Liang CM ，Mou CY ，Chiou SH ... -  《-》

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.

Chien Y ，Chang YL ，Li HY ，Larsson M ，Wu WW ，Chien CS ，Wang CY ，Chu PY ，Chen KH ，Lo WL ，Chiou SH ，Lan YT ，Huo TI ，Lee SD ，Huang PI ... -  《-》

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

Chiang CH ，Wu WW ，Li HY ，Chien Y ，Sun CC ，Peng CH ，Lin AT ，Huang CS ，Lai YH ，Chiou SH ，Hung SI ，Chang YL ，Lan YT ，Liu DM ，Chien CS ，Huo TI ，Lee SD ，Wang CY ... -  《-》

Synthesis and characterization of amphiphatic carboxymethyl-hexanoyl chitosan hydrogel: water-retention ability and drug encapsulation.

Liu TY ，Chen SY ，Lin YL ，Liu DM ... -  《LANGMUIR》

Malignant germ cell-like tumors, expressing Ki-1 antigen (CD30), are revealed during in vivo differentiation of partially reprogrammed human-induced pluripotent stem cells.

Because many of the genes used to produce induced pluripotent stem cells (iPSCs) from somatic cells are either outright established oncogenes, such as c-myc and Klf4, or potentially related to tumorigenesis in various cancers, both the safety and the risks of tumorigenesis linked to iPSC generation require evaluation. In this work, we generated, by lentivirus-mediated gene transfer of Oct4, Sox2, Nanog, and Lin28, two types of iPSCs from human mesenchymal stem cells and human amniotic fluid-derived cells: fully reprogrammed iPSCs with silencing of the four transgenes and partially reprogrammed iPSCs that still express one or several transgenes. We assessed the behavior of these cells during both their differentiation and proliferation using in vivo teratoma assays in nonobese diabetic mice with severe combined immunodeficiency. In contrast to fully reprogrammed iPSCs, 43% of partially reprogrammed iPSC cases (6 of 14 teratomas) generated major dysplasia and malignant tumors, with yolk sac tumors and embryonal carcinomas positive for α-fetoprotein, cytokeratin AE1/AE3, and CD30. This correlated with the expression of one or several transgenes used for the reprogramming, down-regulation of CDK 1A mRNA (p21/CDKN1A), and up-regulation of antiapoptotic Bcl-2 mRNA. Therefore, the oncogenicity of therapeutically valuable patient-specific iPSC-derived cells should be scrupulously evaluated before they are used for any clinical applications.

Griscelli F ，Féraud O ，Oudrhiri N ，Gobbo E ，Casal I ，Chomel JC ，Biéche I ，Duvillard P ，Opolon P ，Turhan AG ，Bennaceur-Griscelli A ... -  《-》