Multiply clustered gold-based nanoparticles complexed with exogenous pDNA achieve prolonged gene expression in stem cells.

Development of a stable and prolonged gene delivery system is a key goal in the gene therapy field. To this end, we designed and fabricated a gene delivery system based on multiply-clustered gold particles that could achieve prolonged gene delivery in stem cells, leading to improved induction of differentiation. : Inorganic gold nanoparticles (AuNPs) underwent three rounds of complexation with catechol-functionalized polyethyleneimine (CPEI) and plasmid DNAs (pDNAs), in that order, with addition of heparin (HP) between rounds, yielding multiply-clustered gold-based nanoparticles (mCGNPs).

Transport distraction osteogenesis with recombinant human bone morphogenic protein-2 for large calvarial defect reconstruction.

Background: Transport distraction osteogenesis (TDO) has been used in attempts to treat large calvarial defects but has, until now, lacked consistency and reliability. To achieve sufficient bone formation, the effect of TDO was compared to the effect of TDO combined with recombinant human bone morphogenic protein-2 (rhBMP-2).

Methods: Fourteen dogs were divided into 2 groups; 6 animals in the control group received TDO only, and 8 received TDO combined with rhBMP-2.

Aggrecan- and COMP-loaded poly-(lactic-co-glycolic acid) nanoparticles stimulate chondrogenic differentiation of human mesenchymal stem cells.

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 proved to be exceedingly difficult. In this study, we developed a safe and efficient protein delivery system using encapsulation of proteins into biodegradable poly-(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs).

Poly(N-isopropylacrylamide-co-acrylic acid) nanogels for tracing and delivering genes to human mesenchymal stem cells.

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.

Multilineage differentiation of human-derived dermal fibroblasts transfected with genes coated on PLGA nanoparticles plus growth factors.

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.

Transfection of VEGF(165) genes into endothelial progenitor cells and in vivo imaging using quantum dots in an ischemia hind limb model.

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.

The use of anti-COX2 siRNA coated onto PLGA nanoparticles loading dexamethasone in the treatment of rheumatoid arthritis.

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.

Exogenous Nurr1 gene expression in electrically-stimulated human MSCs and the induction of neurogenesis.

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.

SOX9 gene plus heparinized TGF-β 3 coated dexamethasone loaded PLGA microspheres for inducement of chondrogenesis of hMSCs.

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.

Co-delivery of SOX9 genes and anti-Cbfa-1 siRNA coated onto PLGA nanoparticles for chondrogenesis of human MSCs.

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).

Chondrogenic potential of stem cells derived from amniotic fluid, adipose tissue, or bone marrow encapsulated in fibrin gels containing TGF-β3.

In this study, several types of hMSCs, derived from bone marrow, adipose tissue, or amniotic fluid, were encapsulated in a fibrin hydrogel mixed with TGF-β3 and then evaluated for their capacity for differentiation in vitro and in vivo. For determination of stem cell differentiation, RT-PCR, real time quantitative PCR (qPCR), histology, and immunohistochemical assays were used for analysis of chondrogenesis. Using these analysis methods, several of the cultured hMSCS were found to highly express genes and proteins specific to cartilage forming tissues.

Chondrogenesis of mesenchymal stem cells and dedifferentiated chondrocytes by transfection with SOX Trio genes.

In this study, bone marrow-derived mesenchymal stem cells (MSCs), adipose-derived mesenchymal stem cells (ASCs) and dedifferentiated chondrocytes were transfected with SOX5, 6, and 9 genes (SOX Trio) and grown under pellet culture conditions (encapsulated in a fibrin hydrogel) to evaluate the chondrogenic potential in vitro and in vivo. RT-PCR, real-time quantitative PCR (qPCR), histology, and immunohistochemical assays were performed to determine the chondrogenic potential of the stem cells and dedifferentiated chondrocytes. Chondrogenic genes and proteins were more highly expressed in SOX Trio-expressing cells than in untransfected cells.

C/EBP-α and C/EBP-β-mediated adipogenesis of human mesenchymal stem cells (hMSCs) using PLGA nanoparticles complexed with poly(ethyleneimmine).

In this study, to drive efficient adipogenic differentiation, the adipogenic transcription factors C/EBP-α and C/EBP-β fused to green fluorescent protein (GFP) or red fluorescent protein (RFP) were complexed with poly-ethyleneimine (PEI) coupled with biodegradable PLGA nanospheres and delivered to human mesenchymal stem cell (hMSC). FACS analysis revealed that the transfection efficiency of C/EBP-α, C/EBP-β, or both genes complexed with PEI-coated PLGA nanospheres was 12.59%, 21.

Transport disc distraction osteogenesis for the reconstruction of a calvarial defect.

Purpose: According to previous reports about the experimental study of transport disk distraction osteogenesis (TDDO) for the reconstruction of bone defects, TDDO showed great feasibility of successful bone regeneration. However, those studies had some limitations in their design and analysis of the results, either. In this report, we intended to verify the effect of TDDO in the reconstruction of skull defects with a combined result of distraction osteogenesis and bone graft of transported disk (TD).

Chondrogenesis of human mesenchymal stem cells mediated by the combination of SOX trio SOX5, 6, and 9 genes complexed with PEI-modified PLGA nanoparticles.

Target gene transfection for desired cell differentiation has recently become a major issue in stem cell therapy. For the safe and stable delivery of genes into human mesenchymal stem cells (hMSCs), we employed a non-viral gene carrier system such as polycataionic polymer, poly(ethyleneimine) (PEI), polyplexed with a combination of SOX5, 6, and 9 fused to green fluorescence protein (GFP), yellow fluorescence protein (YFP), or red fluorescence protein (RFP) coated onto PLGA nanoparticles. The transfection efficiency of PEI-modified PLGA nanoparticle gene carriers was then evaluated to examine the potential for chondrogenic differentiation by carrying the exogenous SOX trio (SOX5, 6, and 9) in hMSCs.

Chondrogenesis of human mesenchymal stem cells in fibrin constructs evaluated in vitro and in nude mouse and rabbit defects models.

In this study, hMSCs encapsulated in a fibrin hydrogel containing heparinized NPs loaded with TGF-β3 (100 ng/ml), or TGF-β3 (100 ng/ml) alone, were subjected to growth factor release and denaturation tests at one, two and four weeks in in vitro culture systems. Additionally, stem cell differentiation was assessed via RT-PCR, real-time quantitative PCR (qPCR), histology, and immunohistochemical assays. In the in vivo studies with nude mouse, when transplanted into nude mice, hMSCs embedded in fibrin hydrogels survived and proliferated more readily in those samples containing TGF-β3-loaded NPs, or TGF-β3 alone, compared to those containing only NPs or the fibrin hydrogel alone.

Effect of input waveform pattern and large blood vessel existence on destruction of liver tumor using radiofrequency ablation: finite element analysis.

Much research has been directed at improving the effectiveness of the radiofrequency (RF) ablation of hepatocellular carcinomas. In that point of view, this study was performed to provide comprehensive information of the relation between RF waveforms and thermodynamic response of the tissue with the consideration of four different types of RF waveforms (half-sine, half-square, half-exponential, and damped-sine) to maximize the amount of tumor tissue removed while maintaining the advantages of RF ablation. For the aim of this study, finite element models incorporating results from previous numerical models were used and validated with ex vivo experiments.

The promotion of chondrogenesis, osteogenesis, and adipogenesis of human mesenchymal stem cells by multiple growth factors incorporated into nanosphere-coated microspheres.

The induction of stem cell differentiation by drugs and growth factors has been the objective of many studies designed to develop methods for the formation of new tissues or the repair of degenerated tissues via transplantation. In this study, drugs and growth factors with high potential for use in tissue repair were embedded in human mesenchymal stem cells (hMSCs), which were then induced to differentiate into chondrogenic, osteogenic, and adipogenic lineages. Additionally, microspheres coated and loaded with the drugs and growth factors successfully proliferated and, as expected, induced the differentiation of transplanted hMSCs into the desired specific cell types.

The use of biodegradable PLGA nanoparticles to mediate SOX9 gene delivery in human mesenchymal stem cells (hMSCs) and induce chondrogenesis.

In stem cell therapy, transfection of specific genes into stem cells is an important technique to induce cell differentiation. To perform gene transfection in human mesenchymal stem cells (hMSCs), we designed and fabricated a non-viral vector system for specific stem cell differentiation. Several kinds of gene carriers were evaluated with regard to their transfection efficiency and their ability to enhance hMSCs differentiation.

Multi-lineage differentiation of hMSCs encapsulated in thermo-reversible hydrogel using a co-culture system with differentiated cells.

The micro-environment is an important factor in the differentiation of cultured stem cells for the purpose of site specific transplantation. In an attempt to optimize differentiation conditions, co-culture systems composed of both stem cells and primary cells or cell lines were used in hydrogel with in vitro and in vivo systems. Stem cells encapsulated in hydrogel, under certain conditions, can undergo increased differentiation both in vitro and in vivo; therefore, reconstruction of transplanted stem cells in a hydrogel co-culture system is important for tissue regeneration.

Low-intensity ultrasound stimulation prevents osteoporotic bone loss in young adult ovariectomized mice.

Osteoporosis is a disease characterized by low bone mass, increased bone fragility, and a greater risk for bone fracture. Currently, pharmacological intervention can generally aid in the prevention and treatment of osteoporosis, but these therapies are often accompanied by undesirable side effects. Therefore, alternative therapies that minimize side effects are necessary.

Osteogenic differentiation of human mesenchymal stem cells using RGD-modified BMP-2 coated microspheres.

Micro-structured scaffolds formed with poly(lactic- co -glycolic acid) (PLGA) microspheres were composed of adhesion molecules and growth factors. PLGA microspheres, constructed with Arg-Gly-Asp (RGD) peptide and bone morphogenic protein 2 (BMP-2) were created as a stem cell delivery vehicle. In this study, a high potential for cell adhesion and differentiation of human mesenchymal stem cells (hMSCs) was achieved by constructing the scaffolds with different compositions of coating materials.

Mechanical properties of blood-mixed polymethylmetacrylate in percutaneous vertebroplasty.

Study Design: Mechanical study of polymethylmetacrylate (PMMA) mixed with blood as a filler.

Purpose: An attempt was made to modify the properties of PMMA to make it more suitable for percutaneous vertebroplasty (PVP).

Overview Of Literature: The expected mechanical changes by adding a filler into PMMA included decreasing the Young's modulus, polymerization temperature and setting time.

Evaluation of the potential clinical application of low-intensity ultrasound stimulation for preventing osteoporotic bone fracture.

This study evaluated the possible clinical application of low-intensity ultrasound (LIUS) stimulation for preventing osteoporotic bone fracture. Eight virgin 14-week-old ICR mice (weight 24.0 +/- 0.

Non-viral gene delivery of DNA polyplexed with nanoparticles transfected into human mesenchymal stem cells.

Human mesenchymal stem cells (hMSCs) represent a potent target for gene delivery for both stem cell differentiation applications and clinical therapies. However, it has, thus far, proven difficult to develop delivery vehicles that increase the efficiency of gene delivery to hMSCs, due to several problematic issues. We have evaluated different vehicles with regard to the efficiency with which they deliver hMSCs and enhance the ability to deliver a reporter gene.