[Show abstract][Hide abstract] ABSTRACT: In cartilage tissue engineering, several kinds of hormones and proteins have been involved in the cascade process of chondrogenic differentiation in stem cells (SCs). In this study, among the potent proteins in chondrogenesis, an aggrecan and cartilage oligomeric matrix protein (COMP)
were evaluated for stimulating agents for the human mesenchymal stem cells (hMSCs). For the efficient delivery into stem cells, an aggrecan and COMP proteins were loaded in the biodegradable poly-(D, L-lactide-co-glycolide) (PLGA) microspheres (MSs) as a single loading formation or double
loading formations as a delivering micro-typed scaffolds for culturing of hMSCs in vitro and transplantation of them in vivo. In order to confirm the stable release from PLGA MSs loading proteins, releasing profiles of protein loaded PLGA MSs were evaluated by confocal laser
microscope in vitro and KODAK imaging analysis in vivo. Internalization of aggrecan and COMPs released from PLGA MSs into hMSCs were imaged using fluorescence-conjugated model drugs and their cytotoxicity was also tested. By these experiments, the proteins-loaded PLGA MSs showed
the high levels of internalization proteins into hMSCs and no cytotoxicities. Induced chondrogenesis of hMSC by supporting of proteins were tested by various molecular methods such as RT-PCR, real time qPCR, Western blotting assay, GAG assay, and histology or immune-histological analysis.
For the confirming of chondrogenesis, cultured and transplanted hMSCs adhered onto PLGA-MSs containing aggrecan and COMP were highly switched into chondrocyte cells both in vitro and in vivo comparing to control groups.
Post Communist Economies 03/2015; 5(3). DOI:10.1166/jbt.2015.1301 · 0.46 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We examined the molecular mechanism of OCT4 gene regulation by polyomavirus enhancer activator 3 (PEA3) in NCCIT cells. Endogenous PEA3 and OCT4 were significantly elevated in undifferentiated cells and reduced upon differentiation. PEA3 knockdown led to a reduction in OCT4 levels. OCT4 promoter activity was significantly up-regulated by dose-dependent PEA3 overexpression. Deletion and site-directed mutagenesis of the OCT4 promoter revealed a putative binding site within the conserved region 2 (CR2). PEA3 interacted with the binding element within CR2 in NCCIT cells. This study reveals the molecular details of the mechanism by which the oncogenic factor PEA3 regulates OCT4 gene expression as a transcriptional activator.
[Show abstract][Hide abstract] ABSTRACT: Quantum dot (QDs) have been employed as bioimaging agents and delivery vehicles for gene therapeutics in several types of cells. In this study, we fabricated multiple QD bundled nanoparticles (NPs) to investigate the effect of QD size and poly(ethylenimine) (PEI) coating on the efficiency of gene delivery into human mesenchymal stem cells (hMSCs). Several types of QDs, which exhibit different ranges of particle size and fluorescence when employed, were coated with PEI to alter their negative charges and to enable them to be bundled into larger particles. Using specific wavelengths of QDs for bioimaging, gene-complexed QD bundled NPs were easily detected in the hMSCs using several different methods such as fluorescence-activated cell sorter, confocal laser scanning microscopy, and in vivo optical imaging. These PEI-coated, bundled QD NPs exhibited significantly higher gene transfection efficacy than single-type QDs. Particularly, the largest QD bundled NPs examined, QD655, had a much higher uptake capability and greater gene expression ability than the other QD NPs (QD525, QD565, and QD605). We believe that our findings help to enrich knowledge of design considerations that will aid in the engineering of QD NPs for stem cell application in the future.
[Show abstract][Hide abstract] ABSTRACT: During stem cell differentiation, various cellular responses occur that are mediated by transcription factors and proteins. This study evaluated the abilities of SOX9, a crucial protein during the early stage of chondrogenesis, and siRNA targeting Cbfa-1, a transcription factor that promotes osteogenesis, to stimulate chondrogenesis. Non-toxic poly-(d,l-lactide-co-glycolide) (PLGA) nanoparticles (NPs) were coated with Cbfa-1-targeting siRNA and loaded with SOX9 protein. Coomassie blue staining and circular dichroism revealed that the loaded SOX9 protein maintained its stability and bioactivity. These NPs easily entered human mesenchymal stem cells (hMSCs) in vitro and caused them to differentiate into chondrocytes. Markers that are typically expressed in mature chondrocytes were examined. These markers were highly expressed at the mRNA and protein levels in hMSCs treated with PLGA NPs coated with Cbfa-1-targeting siRNA and loaded with SOX9 protein. By contrast, these cells did not express osteogenesis-related markers. hMSCs were injected into mice following internalization of PLGA NPs coated with Cbfa-1-targeting siRNA and loaded with SOX9 protein. When the injection site was excised, markers of chondrogenesis were found to be highly expressed at the mRNA and protein levels, similar to the in vitro results. When hMSCs internalized these NPs and were then cultured in vitro or injected into mice, chondrogenesis-related extracellular matrix components were highly expressed.
[Show abstract][Hide abstract] ABSTRACT: Directing the controlled differentiation and tracking of stem cells is essential to achieve successful stem cell therapy. In this work, we describe a multi-modal (MR/optical) transfection agent (MTA) for efficient gene delivery and cell tracking of human mesenchymal stem cells (hMSCs). The MTA was synthesized through a facile two-step approach with 1) ligand exchange of a catechol-functionalized polypeptide (CFP) and 2) chemical immobilization of fluorescence labelled cationic polymer via aminolysis reaction. Cationic polymer-immobilized MTAs with size of ∼40 nm exhibit greatly enhanced colloidal stability in aqueous solution. In addition, the MTAs were capable of binding DNA molecules for transfection. The MTA/pDNA complex showed relatively good transfection efficiency in hMSCs (compared to the commercial transfection agent, Lipofectamine) and good biocompatibility. MTA-treated hMSCs were successfully visualized after transplantation via MR and optical imaging system over 14 days. These studies highlight the challenges associated with the potential advantages of designing multi-modal nanostructured materials as tools for genetic materials delivery and cell-tracking in stem cell therapy.
[Show abstract][Hide abstract] ABSTRACT: Specific genes and growth factors are involved in stem cell differentiation. In this study, we fabricated a delivery carrier for both protein and gene delivery that was introduced into human endothelial progenitor cells (EPCs). The highly negative charge carried by the heparin-modified pluronic nanogels allowed for binding to growth factors and localization in the core of nanogels. The residues of negatively charged heparin can complex with positively charged cationic materials, making it suitable for gene delivery. Supramolecular nanogels can be easily encapsulated the hydrophilic drugs and highly positive surfaces can be complexed with negative charge carrying plasmid DNA (pDNA). The size distribution, gel retardation, and denaturation of encapsulated growth factors and supramolecular nanogels modified with heparin were evaluated. The supramolecular nanogels containing basic fibroblast growth factors and complexing VEGF165 pDNA internalized into EPCs have been well formed vascular formation in matrigel gels. Proteins and genes introduced into EPCs using nanogels promoted neovascularization in an animal model of limb ischemia. EPCs that differentiated into endothelial cells both in vitro and in vivo were tested.
[Show abstract][Hide abstract] ABSTRACT: During embryogenesis, specific proteins expressed in cells have key roles in the formation of differentiated cells and tissues. Delivery of specific proteins into specific cells, both in vitro and in vivo, has proven to be exceedingly difficult. In this study, we developed a safe and efficient protein delivery system using encapsulation of proteins into biodegradable poly-(L-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs). The PLGA NPs were used to deliver proteins into human mesenchymal stem cells (hMSCs). Fluorescent markers loaded into the PLGA NPs were used to verify the internalization of NPs into hMSCs using FACS analysis and confocal microscopy. With these methods, we demonstrated that the encapsulated model proteins are readily delivered into hMSCs, released from the NP vehicles, and, finally, moved into the cytosols. Using chondrogenesis-related proteins such as aggrecan and cartilage origin matrix protein (COMP), chondrogenic differentiation of hMSCs treated with aggrecan and COMP encapsulated PLGA NPs was clearly observed and caused to differentiate into chondrocytes.
Stem cells and development 09/2013; 23(3). DOI:10.1089/scd.2013.0311 · 3.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Drugs, proteins, and cells can be macro- and micro-encapsulated by unique materials that respond to specific stimuli. The phases and hydrophobic interactions of these materials are reversibly altered by environmental stimuli such as pH and temperature. These changes can lead to self-assembly of the materials, which enables controlled drug release and safe gene delivery into cells and tissues. The fate of stem cells delivered by such methods is of great interest. The formation of transgenic tissues requires genes to be delivered safely into stem cells. A cell tracing vehicle and a gene delivery carrier were simultaneously introduced into human mesenchymal stem cells (hMSCs). A thermo-sensitive hydrogel, poly(N-isopropylacrylamide-co-acrylic acid) (p(NiPAAm-co-AAc)), was created to generate self-assembled nanoparticles with nanogel characteristics. Hydrophobic interactions mediated the binding of the carboxyl group on the outside of p(NiPAAm-co-AAc) with the amine group of iron oxide. Nanogels carrying iron oxide and a fluorescent dye were complexed with specific genes. These nanogels could be internalized by hMSCs, and the transplantation of these cells into mice was monitored by in vivo imaging. Self-assembled p(NiPAAm-co-dAAc) nanogels complexed with green fluorescent protein were highly expressed in hMSCs and are a potential material for gene delivery.
[Show abstract][Hide abstract] ABSTRACT: Human adult stem cells are a readily available multipotent cell source that can be used in regenerative medicine. Despite many advantages, including low tumorigenicity, their rapid senescence and limited plasticity have curtailed their use in cell-based therapies. In this study, we isolated CD34/CD73 double-positive (CD34+/CD73+) testicular stromal cells (HTSCs) and found that the expression of CD34 was closely related to the cells' stemness and proliferation. The CD34+/CD73+ cells grew in vitro for an extended period of time, yielding a multitude of cells (5.6 x 1016 cells) without forming tumors in vivo. They also differentiated into all 3 germ layer lineages both in vitro and in vivo, produced cartilage more efficiently compared to bone marrow stem cells and, importantly, restored erectile function in a cavernous nerve crush injury rat model. Thus, these HTSCs may represent a promising new autologous cell source for clinical use.
Stem cells and development 03/2013; 22(15). DOI:10.1089/scd.2012.0385 · 3.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Wounded tissues and cells may be treated with growth factors and specific genes for the purpose of tissue repair and regeneration. To deliver specific genes into tissues and cells, this study presents the use of fabricated poly (dl-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) complexed with the cationic polymer poly (ethleneimine) (PEI). Through complexation with PEI, several types of genes (SOX9, Cbfa1, and C/EBP-α) were coated into PLGA NPs, which enhanced gene uptake into normal human-derived dermal fibroblast cells (NFDHCs) in vitro and in vivo. Several cell types (293T, HeLa, and fibroblast cells) were transfected with fluorescence-tagged PEI/SOX9, PEI/Cbfa1, and PEI/C/EBP-α gene-complexed PLGA NPs. The gene and protein expression levels in the cells were evaluated by RT-PCR, real-time quantitative PCR, Western blotting, and confocal laser microscopy. Fibroblast cells encapsulated in fibrin gels were transfected with the gene-complexed NPs plus specific growth factors (TGF-β3, BMP-2, or IGF/bFGF), which induced chondrogenesis, osteogenesis, or adipogenesis both in vitro and after transplantation into nude mouse.
[Show abstract][Hide abstract] ABSTRACT: Endothelial progenitor cells (EPCs) were transfected with fluorescently labeled quantum dot nanoparticles (QD NPs) with or without VEGF(165) plasmid DNA (pDNA) to probe the EPCs after in vivo transplantation and to test whether they presented as differentiated endothelial cells (ECs). Bare QD NPs and QD NPs coated with PEI or PEI + VEGF(165) genes were characterized by dynamic light scattering, scanning electron microscopy, and atomic force microscopy. Transfection of EPCs with VEGF(165) led to the expression of specific genes and proteins for mature ECs. A hind limb ischemia model was generated in nude mice, and VEGF(165) gene-transfected EPCs were transplanted intramuscularly into the ischemic limbs. At 28 days after transplantation, the VEGF(165) gene-transfected EPCs significantly increased the number of differentiated ECs compared with the injection of medium or bare EPCs without VEGF(165) genes. Laser Doppler imaging revealed that blood perfusion levels were increased significantly by VEGF(165) gene-transfected EPCs compared to EPCs without VEGF(165). Moreover, the transplantation of VEGF(165) gene-transfected EPCs increased the specific gene and protein expression levels of mature EC markers and angiogenic factors in the animal model.
[Show abstract][Hide abstract] ABSTRACT: In drug delivery systems, some genes have the potential to interrupt unnecessary gene expression in specific target cells. In this study, two types of drug, glucocorticoids and siRNA, were co-delivered into conditioned cells to inhibit the expression of unnecessary genes and proteins involved in arthritis. To deliver the two factors into a human chondrocyte cell line (C28/I2), dexamethasone was first loaded into PLGA nanoparticles, and then drug-loaded PLGA nanoparticles were complexed with poly(ethyleneimine) (PEI)/siRNA. To test the co-delivery of siRNA and dexamethasone into chondrocytes, cells were transfected with green fluorescence protein siRNA (GFP siRNA) and drugs. After transfection with GFP siRNA, 70% reduction of C28/I2 cells demonstrated GFP expression, whereas MOCK carrying PLGA nanoparticles and PLGA nanoparticles without siRNA showed no differences of GFP expressions. COX-2 and iNOS productions in C28/I2 cells were examined after TNF-α pre-treatment to induce expression of arthritis-related molecules in vitro. The reduction of gene and protein expression associated with arthritis by transfection with dexamethasone-loaded and COX-2 siRNA-complexed PLGA nanoparticles was evaluated by RT-PCR, real time-qPCR, immunoblotting, immunohistochemistry, and immunofluorescence imaging.
[Show abstract][Hide abstract] ABSTRACT: In this study, synergistic effects of electrical stimulation and exogenous Nurr1 gene expression were examined to induce the differentiation of human mesenchymal stem cells (hMSCs) into nerve cells in in vitro culture system. A two-step procedure was designed to evaluate the effects of electrical stimulus and exogenous gene delivery for inducing neurogenesis. First, an electrical stimulation device was designed using gold nanoparticles adsorbed to the surface of a cover glass. Gold nanoparticles, as an electrical conductor for stem cells, are well-defined particles adsorbed to a polyethyleneimine (PEI)-coated cover glass. The nanoparticle morphology was examined by scanning electron microscope (SEM). Second, a plasmid carrying Nurr1 cDNA was complexed with biodegradable poly-(DL)-lactic-co-glycolic acid (PLGA) nanoparticles to support neurogenesis. To evaluate the neuronal differentiation of stem cells mediated by the treatment with either electrical stimulation and exogenous Nurr1 gene delivery, or both, the expression of neuron-specific genes and proteins was examined by RT-PCR and Western blotting. Cells transfected with exogenous Nurr1 genes plus electrical stimulation (250 mV for 1000 s) showed the greatest level of neurite outgrowth with a mean neurite length of 150 μm. Neurite length in cells treated with only one stimulus was not significant, approximately 10-20 μm. These results indicate that electrical stimulation and exogenous Nurr1 gene expression together may be adequate to induce nerve regeneration using stem cells.
[Show abstract][Hide abstract] ABSTRACT: Microparticulated types of scaffolds have been widely applied in stem cell therapy and the tissue engineering field for the regeneration of wound tissues. During application of simple genes or growth factors and cell delivery vehicles, we designed a method that employs dexamethsone loaded PLGA microspheres consisting of polyplexed SOX9 genes plus heparinized TGF-β 3 on the surface of polymeric microspheres prepared using a layer-by-layer (LbL) method. The fabrication of the polyplexed SOX9 genes plus heparinized TGF-β 3 and their subsequent coating onto dexamethsone loaded PLGA microspheres represents a method for functionalization of the polymeric matrix. The use of SOX9 gene plus heparinized TGF-β 3 coated dexamethsone loaded PLGA microspheres was evaluated to determine their potential as both gene carriers and cell delivery vehicle. By adhesion of hMSCs onto SOX9 gene plus heparinized TGF-β 3 coated dexamethsone loaded PLGA microspheres, the chondrogenesis-related specific genes of collagen type II were increased 30 times comparing to control. Also, the specific extracellular matrix of glycosaminoglycan (GAG) production of hMSCs adhered onto SOX9 gene plus heparinized TGF-β 3 coated dexamethasone loaded PLGA microspheres increased more 2.5 times than control group. Not only in vitro culture but in vivo results, the specific genes of COMP, aggrecan, collagen type II, and SOX9 showed much more gene expressions such as 20, 15, 10, 8 times.
[Show abstract][Hide abstract] ABSTRACT: Some genes expressed in stem cells interrupt and/or enhance differentiation. Therefore, the aim of this study was to inhibit the expression of unnecessary genes and enhance the expression of specific genes involved in stem cell differentiation by using small interfering RNA (siRNA) and plasmid DNA (pDNA) incorporated into cationic polymers as co-delivery factors. To achieve co-delivery of siRNA and pDNA to human mesenchymal stem cells (hMSCs), two different genes were complexed with poly(ethyleneimine) (PEI) and then coated onto poly(lactide-co-glycolic acid) (PLGA) nanoparticles (NP). To evaluate co-delivery of siRNA and pDNA into hMSCs, cells were transfected with green fluorescence protein (GFP) pDNA (GFP pDNA) and GFP siRNA (GFP siRNA). The percentage of GFP-expressing hMSCs decreased from 25.35 to 3.7% after transfection with GFP-DNA/PLGA NP (NPs) or GFP siRNA/PLGA NPs, whereas GFP-DNA/PLGA NPs and scramble siRNA (MOCK)/PLGA NPs had no effect on GFP expression. hMSCs cotransfected with coSOX9-pDNA/NPs and Cbfa-1-siRNA/NPs were tested both in vitro and in vivo using gel retardation, dynamic light scattering (DLS), and scanning electron microscope (SEM). The expression of genes and proteins associated with chondrogenesis was evaluated by FACS, RT-PCR, real time-qPCR, Western blotting, immunohistochemistry, and immunofluorescence imaging.
[Show abstract][Hide abstract] ABSTRACT: A facile in situ supramolecular assembly and modular modification of biocompatible hydrogels were demonstrated using cucurbituril-conjugated hyaluronic acid (CB-HA), diaminohexane-conjugated HA (DAH-HA), and tags-CB for cellular engineering applications. The strong and selective host-guest interaction between CB and DAH made possible the supramolecular assembly of CB/DAH-HA hydrogels in the presence of cells. Then, the 3D environment of CB/DAH-HA hydrogels was modularly modified by the simple treatment with various multifunctional tags-CB. Furthermore, we could confirm in situ formation of CB/DAH-HA hydrogels under the skin of nude mice by sequential subcutaneous injections of CB-HA and DAH-HA solutions. The fluorescence of modularly modified fluorescein isothiocyanate (FITC)-CB in the hydrogels was maintained for up to 11 days, reflecting the feasibility to deliver the proper cues for cellular proliferation and differentiation in the body. Taken together, CB/DAH-HA hydrogels might be successfully exploited as a 3D artificial extracellular matrix for various tissue engineering applications.