Osteogenic differentiation of human dental pulp stem cells on β-tricalcium phosphate/poly (l-lactic acid/caprolactone) three-dimensional scaffolds.

Functional tissue engineering for bone augmentation requires the appropriate combination of biomaterials, mesenchymal stem cells, and specific differentiation factors. Therefore, we investigated the morphology, attachment, viability, and proliferation of human dental pulp stem cells cultured in xeno-free conditions in human serum medium seeded on β-tricalcium phosphate/poly(l-lactic acid/caprolactone) three-dimensional biomaterial scaffold. Additionally, osteogenic inducers dexamethasone and vitamin D(3) were compared to achieve osteogenic differentiation.

Effects of bioactive glass S53P4 or beta-tricalcium phosphate and bone morphogenetic protein-2 and bone morphogenetic protein-7 on osteogenic differentiation of human adipose stem cells.

The effects of bioactive glass S53P4 or beta-tricalcium phosphate; and bone morphogenetic proteins bone morphogenetic protein-2, bone morphogenetic protein-7, or bone morphogenetic protein-2 + 7 on osteogenic differentiation of human adipose stem cells were compared in control medium, osteogenic medium, and bone morphogenetic protein-supplemented osteogenic medium to assess suitability for bone tissue engineering. Cell amount was evaluated with qDNA measurements; osteogenic differentiation using marker gene expression, alkaline phosphate activity, and angiogenic potential was measured by vascular endothelial growth factor expression. As compared to beta-tricalcium phosphate, cell amount was significantly greater for bioactive glass in control medium after 7 days and in osteogenic medium after 14 days, and alkaline phosphate activity was always significantly greater for bioactive glass in control medium.

Effects of chitosan and bioactive glass modifications of knitted and rolled polylactide-based 96/4 L/D scaffolds on chondrogenic differentiation of adipose stem cells.

The performance of biodegradable knitted and rolled 3-dimensional (3D) polylactide-based 96/4 scaffolds modified with bioactive glass (BaG) 13-93, chitosan and both was compared with regard to the viability, proliferation and chondrogenic differentiation of rabbit adipose stem cells (ASCs). Scaffold porosities were determined by micro-computed tomography (μCT). Water absorption and degradation of scaffolds were studied during 28-day hydrolysis in Tris-buffer.

Amniotic membrane reduces wound size in early stages of the healing process.

Objective: To investigate the effects of dispase de-epithelialised, glycerol cryopreserved amniotic membrane (AM) on full-thickness skin defects, using a rat model.

Method: Skin defects of 15 mm diameter were surgically created and measured on the scalps of 53 male rats. Animals were divided into two groups and followed for 0, 3, 7, 14 or 21 days.

Efflux protein expression in human stem cell-derived retinal pigment epithelial cells.

Retinal pigment epithelial (RPE) cells in the back of the eye nourish photoreceptor cells and form a selective barrier that influences drug transport from the blood to the photoreceptor cells. At the molecular level, ATP-dependent efflux transporters have a major role in drug delivery in human RPE. In this study, we assessed the relative expression of several ATP-dependent efflux transporter genes (MRP1, -2, -3, -4, -5, -6, p-gp, and BCRP), the protein expression and localization of MRP1, MRP4, and MRP5, and the functionality of MRP1 efflux pumps at different maturation stages of undifferentiated human embryonic stem cells (hESC) and RPE derived from the hESC (hESC-RPE).

Screening ethnically diverse human embryonic stem cells identifies a chromosome 20 minimal amplicon conferring growth advantage.

The International Stem Cell Initiative analyzed 125 human embryonic stem (ES) cell lines and 11 induced pluripotent stem (iPS) cell lines, from 38 laboratories worldwide, for genetic changes occurring during culture. Most lines were analyzed at an early and late passage. Single-nucleotide polymorphism (SNP) analysis revealed that they included representatives of most major ethnic groups.

In Vivo and In Vitro Study of a Polylactide-Fiber-Reinforced β-Tricalcium Phosphate Composite Cage in an Ovine Anterior Cervical Intercorporal Fusion Model.

A poly-70L/30DL-lactide (PLA70)-β-tricalcium phosphate (β-TCP) composite implant reinforced by continuous PLA-96L/4D-lactide (PLA96) fibers was designed for in vivo spinal fusion. The pilot study was performed with four sheep, using titanium cage implants as controls. The composite implants failed to direct bone growth as desired, whereas the bone contact and the proper integration were evident with controls 6 months after implantation.

Laminin-511 expression is associated with the functionality of feeder cells in human embryonic stem cell culture.

Fibroblast feeder cells play an important role in supporting the derivation and long term culture of undifferentiated, pluripotent human embryonic stem cells (hESCs). The feeder cells secrete various growth factors and extracellular matrix (ECM) proteins into extracellular milieu. However, the roles of the feeder cell-secreted factors are largely unclear.

Impedance spectroscopy in monitoring the maturation of stem cell-derived retinal pigment epithelium.

The development and differentiation of stem cell-derived impermeable retinal pigment epithelium (RPE) with tight junctions (TJs) is a gradual process that is, at confluence, controlled by cell-to-cell contact. The objective of this study was to evaluate the use of electric impedance spectroscopy (EIS) to follow the maturation and development of barrier function in human embryonic stem cell-derived RPE (hESC-RPE). Barrier function was assessed using EIS, permeability measurements, and microscopic inspection in intact cells and following calcium sequestration with ethylene glycol tetraacetic acid (EGTA).

A xeno-free culturing protocol for pluripotent stem cell-derived oligodendrocyte precursor cell production.

Aim: To show that human embryonic stem cells (hESCs) can be efficiently differentiated into oligodendrocyte precursor cells (OPCs) in a xeno-free medium with a specific medium supplement and specific human recombinant growth factors.

Materials & Methods: The xeno-free OPC-differentiation medium for pluripotent stem cells was developed by using StemPro® neural stem cell xeno-free medium supplement together with human recombinant growth factors SHH, PDGF-AA, IGF-1, EGF, basic FGF and CNTF, in addition to RA, T3, human laminin and ascorbic acid. We analyzed the differentiated hESC-derived OPCs and oligodendrocytes with quantitative real-time (RT)-PCR, RT-PCR, flow cytometry and immunocytochemistry, and we performed NG2-positive selection for OPC cultures with fluorescence-activated cell sorting.

The effects of vibration loading on adipose stem cell number, viability and differentiation towards bone-forming cells.

Mechanical stimulation is an essential factor affecting the metabolism of bone cells and their precursors. We hypothesized that vibration loading would stimulate differentiation of human adipose stem cells (hASCs) towards bone-forming cells and simultaneously inhibit differentiation towards fat tissue. We developed a vibration-loading device that produces 3g peak acceleration at frequencies of 50 and 100 Hz to cells cultured on well plates.

Toward the defined and xeno-free differentiation of functional human pluripotent stem cell-derived retinal pigment epithelial cells.

Purpose: The production of functional retinal pigment epithelium (RPE) cells from human embryonic (hESCs) and human induced pluripotent stem cells (hiPSCs) in defined and xeno-free conditions is highly desirable, especially for their use in cell therapy for retinal diseases. In addition, differentiated RPE cells provide an individualized disease model and drug discovery tool. In this study, we report the differentiation of functional RPE-like cells from several hESC lines and one hiPSC line in culture conditions, enabling easy translation to clinical quality cell production under Good Manufacturing Practice regulations.

Cranioplasty with adipose-derived stem cells and biomaterial: a novel method for cranial reconstruction.

Background: There is no optimal method for reconstruction of large calvarial defects. Because of the limitations of autologous bone grafts and alloplastic materials, new methods for performing cranioplasties are needed.

Objective: To create autologous bone to repair cranial defects.

Comparison of a poly-L-lactide-co-ε-caprolactone and human amniotic membrane for urothelium tissue engineering applications.

The reconstructive surgery of urothelial defects, such as severe hypospadias is susceptible to complications. The major problem is the lack of suitable grafting materials. Therefore, finding alternative treatments such as reconstruction of urethra using tissue engineering is essential.

Human cell-based micro electrode array platform for studying neurotoxicity.

At present, most of the neurotoxicological analyses are based on in vitro and in vivo models utilizing animal cells or animal models. In addition, the used in vitro models are mostly based on molecular biological end-point analyses. Thus, for neurotoxicological screening, human cell-based analysis platforms in which the functional neuronal networks responses for various neurotoxicants can be also detected real-time are highly needed.

Markers of pluripotency and differentiation in human neural precursor cells derived from embryonic stem cells and CNS tissue.

Cell transplantation therapies for central nervous system (CNS) deficits such as spinal cord injury (SCI) have been shown to be effective in several animal models. One cell type that has been transplanted is neural precursor cells (NPCs), for which there are several possible sources. We have studied NPCs derived from human embryonic stem cells (hESCs) and human fetal CNS tissue (hfNPCs), cultured as neurospheres, and the expression of pluripotency and neural genes during neural induction and in vitro differentiation.

Similarly derived and cultured hESC lines show variation in their developmental potential towards neuronal cells in long-term culture.

Background: Human embryonic stem cells (hESCs) can differentiate into any human cell type, including CNS cells, and thus have high potential in regenerative medicine. Several protocols exist for neuronal differentiation of hESCs, which do not necessarily work for all hESC lines.

Materials & Methods: We tested the differentiation capacity of four similarly derived and cultured hESC lines (HS181, HS360, HS362 and HS401) in suspension culture in relatively simple neural differentiation medium for up to 20 weeks.

The potential of adipose stem cells in regenerative medicine.

Adipose stem cells (ASCs) are an attractive and abundant stem cell source with therapeutic applicability in diverse fields for the repair and regeneration of acute and chronically damaged tissues. Importantly, unlike the human bone marrow stromal/stem stem cells (BMSCs) that are present at low frequency in the bone marrow, ASCs can be retrieved in high number from either liposuction aspirates or subcutaneous adipose tissue fragments and can easily be expanded in vitro. ASCs display properties similar to that observed in BMSCs and, upon induction, undergo at least osteogenic, chondrogenic, adipogenic and neurogenic, differentiation in vitro.

Comparison of the stability of bioabsorbable and titanium osteosynthesis materials for rigid internal fixation in orthognathic surgery. A prospective randomized controlled study in 101 patients with 192 osteotomies.

The purpose of this study was to evaluate the stability of rigid internal fixation in orthognathic surgery with either bioabsorbable or titanium osteosynthesis. Orthognathic surgery was performed on 101 patients. Bilateral sagittal ramus osteotomy was performed on 55 patients using bioabsorbable osteosynthesis in 26 and titanium osteosynthesis in 29 patients.

Vitamin D(3) metabolites induce osteogenic differentiation in human dental pulp and human dental follicle cells.

Vitamin D(3) metabolites regulate the bone metabolism and 1α,25-dihydroxyvitamin D(3) (1α,25(OH)(2)D(3)) is known to play an important role in teeth mineralization. However, little is known about the potential of vitamin D as an osteogenic inducer in human dental pulp (hDPCs) and dental follicle cells (hDFCs) in vitro. Therefore, we investigated the effects of vitamin D(3) metabolites 1α,25(OH)(2)D(3) and 25-hydroxyvitamin D(3) (25OHD(3)) on proliferation and osteogenic differentiation of hDPCs and hDFCs in vitro.

Addition of BMP-2 or BMP-6 to dexamethasone, ascorbic acid, and β-glycerophosphate may not enhance osteogenic differentiation of human periodontal ligament cells.

This study was designed to investigate the potential merits of the combined use of bone morphogenetic protein (BMP)-2 or BMP-6 and osteogenic supplements (OS) [dexamethasone, ascorbic acid (AA), and β-glycerophosphate] on osteogenic differentiation of periodontal ligament cells (PDLCs). Osteogenic differentiation was evaluated by quantitative alkaline phosphatase (ALP) assay, alizarin red staining, quantitative calcium assay, and the qRT-PCR analysis for the expression of collagen type I, runt-related transcription factor-2, osteopontin (OPN), and osteocalcin in PDLCs. Culture with BMP-2 or BMP-6+AA increased ALP activity of PDLCs, suggesting their osteo-inductive effects.

Production and isolation of NG2+ oligodendrocyte precursors from human embryonic stem cells in defined serum-free medium.

Human embryonic stem cells (hESCs) are a promising source of oligodendrocyte precursor cells (OPCs) and oligodendrocytes. These cells can be used to repair myelin in central nervous system deficits such as multiple sclerosis or traumas such as spinal cord injury. Here, we introduce a novel differentiation method for the production of OPCs from hESCs.

A defined and xeno-free culture method enabling the establishment of clinical-grade human embryonic, induced pluripotent and adipose stem cells.

Background: The growth of stem cells in in vitro conditions requires optimal balance between signals mediating cell survival, proliferation, and self-renewal. For clinical application of stem cells, the use of completely defined conditions and elimination of all animal-derived materials from the establishment, culture, and differentiation processes is desirable.

Methodology/principal Findings: Here, we report the development of a fully defined xeno-free medium (RegES), capable of supporting the expansion of human embryonic stem cells (hESC), induced pluripotent stem cells (iPSC) and adipose stem cells (ASC).

Human embryonic stem cell-derived cardiomyocytes: demonstration of a portion of cardiac cells with fairly mature electrical phenotype.

Cardiomyocytes (CMs) derived from human embryonic stem cells (hESC) provide a promising tool for the pharmaceutical industry. In this study the electrical properties and maturation of hESC-CM derived using two differentiation methods were compared and the suitability of hESC-CMs as a cell model for the assessment of drug-induced repolarization delay was evaluated. CMs were differentiated either in END-2 co-culture or by spontaneous differentiation.

Spatial and temporal expression pattern of germ layer markers during human embryonic stem cell differentiation in embryoid bodies.

Human embryonic stem cell (hESC) differentiation in embryoid bodies (EBs) provides a valuable tool to study the interplay of different germ layers and their influence on cell differentiation. The gene expression of the developing EBs has been shown in many studies, but the protein expression and the spatial composition of different germ layers in human EBs have not been systematically studied. The aim of the present work was to study the temporal and spatial organisation of germ layers based on the expression of mesoderm (Brachyury T), endoderm (AFP) and ectoderm (SOX1) markers during the early stages of differentiation in eight hESC lines.