PD-1-CD28-enhanced receptor and CD19 CAR-modified tumor-infiltrating T lymphocytes produce potential anti-tumor ability in solid tumors.

The limited expansion ability and functional inactivation of T cells within the solid tumor microenvironment are major problems faced during in the application of using tumor-infiltrating lymphocytes (TILs) in vivo. We sought to determine whether TILs carrying a PD-1-CD28-enhanced receptor and CD19 CAR could overcome this limitation and mediate tumor regression. First, anti-tumor effects of PD-1-CD28-enhanced receptor or CD19 CAR modified NY-ESO-1-TCR-T cells to mimic the TILs function (hereafter "PD-1-CD28-TCR-T" or "CD19 CAR-TCR-T" cells, respectively) were tested using the NY-ESO-1 over-expressed tumor cell line in vitro and in a tumor-bearing model. Furthermore, the safety and anti-tumor ability of S-TILs (TILs modified through transduction with a plasmid encoding the PD-1-CD28-T2A-CD19 CAR) were evaluated in vivo. PD-1-CD28-TCR-T cells showed a formidable anti-tumor ability that was not subject to PD-1/PD-L1 signaling in vivo. CD19 CAR-TCR-T cells stimulated with CD19+ B cells exhibited powerful expansion and anti-tumor abilities both in vitro and in vivo. Three patients with refractory solid tumors received S-TILs infusion. No treatment-related mortality was observed, and none of the patients experienced serious side effects. One patient with melanoma achieved a partial response, and two patients with colon or kidney cancer achieved long-term stable disease following S-TILs therapy. To the best of our knowledge, this is the first study describing the safety and efficacy of the adoptive transfer of autologous S-TILs to control disease in patients with advanced cancers, suggesting that S-TILs may be a promising alternative therapy for cancer.

Static pressure-induced neural differentiation of mesenchymal stem cells.

Growing experimental evidence suggests that physical cues play an important role in regulating the fate of stem cells and stimulating their differentiation behavior. We report here that static pressure enables the differentiation of rat bone marrow-derived mesenchymal stem cells (MSCs) into neural-like cells within several hours in the absence of disruptive bio-factors or chemicals. The realization of such differentiation is supported by the observation of characteristic morphology of neural-like cells with neurites, and an up-regulated expression level of neural-specific markers. Our finding also demonstrates the utility of the static pressure-based approach for in situ and specifically localized creation of neural cell systems, thereby providing profound implications for developing therapeutic application of stem cells.

A Nanostructured Molybdenum Disulfide Film for Promoting Neural Stem Cell Neuronal Differentiation: toward a Nerve Tissue-Engineered 3D Scaffold.

Physical cues from nanostructured biomaterials have been shown to possess regulating effects on stem cell fate. In this study, nanostructured molybdenum disulfide (MoS2 ) thin films (MTFs) are prepared by assembling MoS2 nanosheets on a flat substrate. These films are used as a new biocompatible platform for promoting neural stem cell (NSC) differentiation. The results show that the nanostructured MTFs exhibit significantly positive effects on NSC attachment and proliferation without measurable toxicity. More importantly, immunostaining and real-time polymerase chain reaction assessments show that the nanostructured MTFs induce NSC differentiation into neural cells at higher efficiency. It is found that the MTFs have a good electrical conductivity and offer larger surface areas for NSC attachment and spreading compared with conventional tissue culture plates. Furthermore, multilayered cylindrical 3D living scaffolds are constructed by rolling up NSC-cultured MoS2 -polyvinylidene fluoride (PVDF) nanofiber films that are prepared by chemically assembling MoS2 nanostructures on electrospun PVDF flexible films. These living nerve scaffolds have a great potential for applications in nerve regeneration as cylindrical 3D living scaffolds.

Localized committed differentiation of neural stem cells based on the topographical regulation effects of TiO2 nanostructured ceramics.

In this study, a porous-flat TiO2 micropattern was fabricated with flat and nanoporous TiO2 ceramics for investigating the effect of topography on neural stem cell (NSC) differentiation. This finding demonstrates that localized committed differentiation could be achieved in one system by integrating materials with different topographies.

Rutile Nanorod/Anatase Nanowire Junction Array as Both Sensor and Power Supplier for High-Performance, Self-Powered, Wireless UV Photodetector.

Self-powered UV photodetectors based on TiO2 nanotree arrays have captured much attention in recent years because of their many advantages. In this work, rutile/anatase TiO2 (R/A-TiO2 ) heterostructured nanotree arrays are fabricated by assembling anatase nanowires as branches on rutile nanorods. External quantum efficiencies as high as 90% are reached at 325 nm. These high quantum efficiencies are related to the higher amount of light harvesting due to the larger surface area, the better separation ability of the photogenerated carriers by the rutile/anatase heterostructure, and the faster electron transport, related to the 1D nanostructure and lattice connection at the interface of the two kinds of TiO2 . Furthermore, a self-powered wireless UV photodetector is shown with excellent wireless detection performance. Such devices will enable significant advances for next-generation photodetection and photosensing applications.

Construction of titanium dioxide nanorod/graphite microfiber hybrid electrodes for a high performance electrochemical glucose biosensor.

The demand for a highly sensitive and selective glucose biosensor which can be used for implantable or on-time monitoring is constantly increasing. In this work, TiO2 nanorods were synthesized in situ on the surface of graphite microfibers to yield TiO2 nanorod/graphite microfiber hybrid electrodes. The TiO2 nanorods not only retain the high activity of the immobilized glucose molecule, but also promote the direct electron transfer process on the electrode surface. As a working electrode in an electrochemical glucose biosensor in a flowing system, the microfiber hybrid electrodes exhibit high sensitivity, selectivity and stability. Due to its simplicity, low cost, high stability, and unique morphology, the TiO2 nanorod/graphite microfiber hybrid electrode is expected to be an excellent candidate for an implantable biosensor or for in situ flow monitoring.

Cellular internalization of LiNbO3 nanocrystals for second harmonic imaging and the effects on stem cell differentiation.

Second harmonic generation (SHG) nanocrystals have recently been reported to label cancer cells and other functional cell lines due to their unique double-frequency property. In this paper, we report for the first time the use of lithium niobate (LiNbO3, LN) nanocrystals as SHG labels for imaging stem cells. Rat mesenchymal stem cells (rMSCs) were labeled with LN nanocrystals in order to study the cellular internalization of the nanocrystals and the influence on stem cell differentiation. The results showed that LN nanocrystals were endocytosed by the rMSCs and the distribution of the internalized nanoparticles demonstrated a high consistency with the orientation of the actin filaments. Besides, LN-labeled rMSCs showed a concentration-dependent viability. Most importantly, rMSCs labeled with 50 µg per mL of LN nanocrystals retained their ability to differentiate into both osteogenic and adipogenic lineages. The results prove that LN nanocrystals can be used as a cytocompatible, near-infrared (NIR) light driven cell label for long-term imaging, without hindering stem cell differentiation. This work will promote the use of LN nanocrystals to broader applications like deep-tissue tracking, remote drug delivery and stem cell therapy.

Effects of Graphene Quantum Dots on the Self-Renewal and Differentiation of Mesenchymal Stem Cells.

The influence of graphene quantum dots (GQDs) on key characteristics of bone marrow derived mesenchymal stem cells (MSCs) phenotype (i.e., self-renewal, differentiation potential, and pluripotency) is systematically investigated in this work. First, the viability and impact of GQDs on the self-renewal potential of MSCs is evaluated in order to determine a threshold for the exposing dose. Second, GQDs uptake by MSCs is confirmed due to the excellent fluorescent properties of the particles. They exhibit a homogenous cytoplasmatic distribution that increases with the time and concentration. Third, the impact of GQDs on the osteogenic differentiation of MSCs is deeply characterized. An enhanced activity of alkaline phosphatase promoted by GQDs indicates early activation of osteogenesis. This is also confirmed upon GQD-induced up-regulation of phenotypically related osteogenic genes (Runx2, osteopontin, and osteocalcin) and specific biomarkers expression (osteopontin and osteocalcin). GQDs also effectively enhance the formation of calcium-rich deposits characteristics of osteoblasts. Furthermore, genes microarray results indicate that the enhanced osteogenic differentiation of MSCs by GQDs is in progress through a bone morphogenetic protein and transforming growth factor-ß relative signaling pathways. Finally, intracytoplasmatic lipid detection shows that GQDs can also promote the adipogenic differentiation of MSCs, thus confirming the prevalence of their pluripotency potential.

Construction of a 3D rGO-collagen hybrid scaffold for enhancement of the neural differentiation of mesenchymal stem cells.

The cell-material interface is one of the most important considerations in designing a high-performance tissue engineering scaffold because the surface of the scaffold can determine the fate of stem cells. A conductive surface is required for a scaffold to direct stem cells toward neural differentiation. However, most conductive polymers are toxic and not amenable to biological degradation, which restricts the design of neural tissue engineering scaffolds. In this study, we used a bioactive three-dimensional (3D) porcine acellular dermal matrix (PADM), which is mainly composed of type I collagen, as a basic material and successfully assembled a layer of reduced graphene oxide (rGO) nanosheets on the surface of the PADM channels to obtain a porous 3D, biodegradable, conductive and biocompatible PADM-rGO hybrid neural tissue engineering scaffold. Compared with the PADM scaffold, assembling the rGO into the scaffold did not induce a significant change in the microstructure but endowed the PADM-rGO hybrid scaffold with good conductivity. A comparison of the neural differentiation of rat bone-marrow-derived mesenchymal stem cells (MSCs) was performed by culturing the MSCs on PADM and PADM-rGO scaffolds in neuronal culture medium, followed by the determination of gene expression and immunofluorescence staining. The results of both the gene expression and protein level assessments suggest that the rGO-assembled PADM scaffold may promote the differentiation of MSCs into neuronal cells with higher protein and gene expression levels after 7 days under neural differentiation conditions. This study demonstrated that the PADM-rGO hybrid scaffold is a promising scaffold for neural tissue engineering; this scaffold can not only support the growth of MSCs at a high proliferation rate but also enhance the differentiation of MSCs into neural cells.

Surface charge regulation of osteogenic differentiation of mesenchymal stem cell on polarized ferroelectric crystal substrate.

Polarized ferroelectric crystal lithium niobate wafers with different cuts are selected to offer differently charged surfaces. By induction of the mesenchymal stem cells differentiation into osteoblasts on different charged surfaces, the specific osteogenic-associated markers are assessed and the results illustrate that the positively charged wafer surface enhances rBMMSCs osteogenic differentiation.

Biopolymer/Calcium phosphate scaffolds for bone tissue engineering.

With nearly 30 years of progress, tissue engineering has shown promise in developing solutions for tissue repair and regeneration. Scaffolds, together with cells and growth factors, are key components of this development. Recently, an increasing number of studies have reported on the design and fabrication of scaffolding materials. In particular, inspired by the nature of bone, polymer/ceramic composite scaffolds have been studied extensively. The purpose of this paper is to review the recent progress of the naturally derived biopolymers and the methods applied to generate biomimetic biopolymer/calcium phosphate composites as well as their biomedical applications in bone tissue engineering.

Graphene oxide-reinforced biodegradable genipin-cross-linked chitosan fluorescent biocomposite film and its cytocompatibility.

A genipin-cross-linked chitosan/graphene oxide (GCS/GO) composite film was prepared using a solution casting method. Fourier transform infrared (FTIR) and ultraviolet-visible (UV-Vis) spectroscopy of the composite films showed that the interactions between the CS and oxygen-containing groups of GO resulted in good dispersion of the GO sheets in the CS network. The addition of GO decreased the expansion ratio of the composite films in physiological conditions and increased the resistance to degradation by lysozymes in vitro. As well, the tensile strength values of the GCS/GO films were significantly increased with the increasing load of GO. Moreover, the GCS/GO composite film also maintained the intrinsic fluorescence of GCS. The in vitro cell study results revealed that the composite films were suitable for the proliferation and adhesion of mouse preosteoblast (MC3T3-E1) cells. The GCS/GO biocomposite films might have a potential use in tissue engineering, bioimaging, and drug delivery.

Generation of disease-specific induced pluripotent stem cells from patients with different karyotypes of Down syndrome.

INTRODUCTION: Down syndrome (DS), a major cause of mental retardation, is caused by trisomy of some or all of human chromosome 21 and includes three basic karyotypes: trisomy 21, translocation, and mosaicism. The derivation of DS-specific induced pluripotent stem cells (iPSCs) provides us novel DS models that can be used to determine the DS mechanism and to devise therapeutic approaches for DS patients. METHODS: In the present study, fibroblasts from patients with DS of various karyotypes were reprogrammed into iPSCs via the overexpression of four factors: OCT4, SOX2, KLF4, and c-MYC, by using lentiviral vectors. The abilities of the iPSC-DS in the self-renewal and pluripotency in vitro and in vivo were then examined. RESULTS: The iPSC-DS showed characteristics similar to those of human embryonic stem cells, particularly the morphology, surface marker (SSEA4, TRA-1-60, and TRA-1-81) expression, pluripotent-specific transcription-factor expression levels, and methylation status of the OCT4 promoter. The pluripotency of iPSC-DS was also tested in vitro and in vivo. Embryoid bodies were formed and showed the expression of differentiated markers for three germ layers. Furthermore, iPSC-DS formed classic teratomas when injected into nonobese diabetic-severe combined immunodeficient (NOD-SCID) mice. CONCLUSIONS: iPSCs were generated from patients with DS. The iPSCs derived from different types of DS may be used in DS modeling, patient-care optimization, drug discovery, and eventually, autologous cell-replacement therapies.

A novel xeno-free and feeder-cell-free system for human pluripotent stem cell culture.

While human induced pluripotent stem cells (hiPSCs) have promising applications in regenerative medicine, most of the hiPSC lines available today are not suitable for clinical applications due to contamination with nonhuman materials, such as sialic acid, and potential pathogens from animal-product-containing cell culture systems. Although several xeno-free cell culture systems have been established recently, their use of human fibroblasts as feeders reduces the clinical potential of hiPSCs due to batch-to-batch variation in the feeders and time-consuming preparation processes. In this study, we have developed a xeno-free and feeder-cell-free human embryonic stem cell (hESC)/hiPSC culture system using human plasma and human placenta extracts. The system maintains the self-renewing capacity and pluripotency of hESCs for more than 40 passages. Human iPSCs were also derived from human dermal fibroblasts using this culture system by overexpressing three transcription factors-Oct4, Sox2 and Nanog. The culture system developed here is inexpensive and suitable for large scale production.