Bone Formation from Porcine Dental Germ Stem Cells on Surface Modified Polybutylene Succinate Scaffolds

Designing and providing a scaffold are very important for the cells in tissue engineering. Polybutylene succinate (PBS) has high potential as a scaffold for bone regeneration due to its capacity in cell proliferation and differentiation. Also, stem cells from 3rd molar tooth germs were favoured in this study due to their developmentally and replicatively immature nature. In this study, porcine dental germ stem cells (pDGSCs) seeded PBS scaffolds were used to investigate the effects of surface modification with fibronectin or laminin on these scaffolds to improve cell attachment, proliferation, and osteogenic differentiation for tissue engineering applications. The osteogenic potentials of pDGSCs on these modified and unmodified foams were examined to heal bone defects and the effects of fibronectin or laminin modified PBS scaffolds on pDGSC differentiation into bone were compared for the first time. For this study, MTS assay was used to assess the cytotoxic effects of modified and unmodified surfaces. For the characterization of pDGSCs, flow cytometry analysis was carried out. Besides, alkaline phosphatase (ALP) assay, von Kossa staining, real-time PCR, CM-Dil, and immunostaining were applied to analyze osteogenic potentials of pDGSCs. The results of these studies demonstrated that pDGSCs were differentiated into osteogenic cells on fibronectin modified PBS foams better than those on unmodified and laminin modified PBS foams

Tissue Engineered, Guided Nerve Tube Consisting of Aligned Neural Stem Cells and Astrocytes

Injury of the nervous system, particularly in the spinal cord, impairs the quality of life of the patient by resulting in permanent loss of neurologic function. The main limitation in spinal cord regeneration is the lack of extracellular matrix to guide nerves for functional recovery of the transected nerve tissue. In the present study, a tissue engineered nerve tube was prepared by wrapping neural stem cells (NSCs) on aligned fibers using a micropatterned film with astrocytes aligned along the microgrooves to support the NSCs. Initially the cell behavior on micropatterns and parallel fibers was investigated with cytoskeletal and nuclear staining, immunocytochemistry, and proliferation assay using the fiber and the film system separately. The results showed that both cells, NSCs in undifferentiated and astrocytes in differentiated form, were oriented in the direction of the guiding and support elements, the microgrooves, and the microfibers. They were able to grow and increase in number on these cell carriers. This trend was also maintained after the components were brought together in a nerve tube form and testing in coculture. The cells were able to survive and maintained their orientation in the 3D tissue engineered construct. The guided nerve tissue engineering approach tested in the present study with parallel NSCs and support cells in the tubular construct is expected to provide an appropriate environment for nerve regeneration in vivo

Tissue Engineered, Guided Nerve Tube Consisting of Aligned Neural Stem Cells and Astrocytes

Injury of the nervous system, particularly in the spinal cord, impairs the quality of life of the patient by resulting in permanent loss of neurologic function. The main limitation in spinal cord regeneration is the lack of extracellular matrix to guide nerves for functional recovery of the transected nerve tissue. In the present study, a tissue engineered nerve tube was prepared by wrapping neural stem cells (NSCs) on aligned fibers using a micropatterned film with astrocytes aligned along the microgrooves to support the NSCs. Initially the cell behavior on micropatterns and parallel fibers was investigated with cytoskeletal and nuclear staining, immunocytochemistry, and proliferation assay using the fiber and the film system separately. The results showed that both cells, NSCs in undifferentiated and astrocytes in differentiated form, were oriented in the direction of the guiding and support elements, the microgrooves, and the microfibers. They were able to grow and increase in number on these cell carriers. This trend was also maintained after the components were brought together in a nerve tube form and testing in coculture. The cells were able to survive and maintained their orientation in the 3D tissue engineered construct. The guided nerve tissue engineering approach tested in the present study with parallel NSCs and support cells in the tubular construct is expected to provide an appropriate environment for nerve regeneration in vivo

Bone Formation from Porcine Dental Germ Stem Cells on Surface Modified Polybutylene Succinate Scaffolds

Designing and providing a scaffold are very important for the cells in tissue engineering. Polybutylene succinate (PBS) has high potential as a scaffold for bone regeneration due to its capacity in cell proliferation and differentiation. Also, stem cells from 3rd molar tooth germs were favoured in this study due to their developmentally and replicatively immature nature. In this study, porcine dental germ stem cells (pDGSCs) seeded PBS scaffolds were used to investigate the effects of surface modification with fibronectin or laminin on these scaffolds to improve cell attachment, proliferation, and osteogenic differentiation for tissue engineering applications. The osteogenic potentials of pDGSCs on these modified and unmodified foams were examined to heal bone defects and the effects of fibronectin or laminin modified PBS scaffolds on pDGSC differentiation into bone were compared for the first time. For this study, MTS assay was used to assess the cytotoxic effects of modified and unmodified surfaces. For the characterization of pDGSCs, flow cytometry analysis was carried out. Besides, alkaline phosphatase (ALP) assay, von Kossa staining, real-time PCR, CM-Dil, and immunostaining were applied to analyze osteogenic potentials of pDGSCs. The results of these studies demonstrated that pDGSCs were differentiated into osteogenic cells on fibronectin modified PBS foams better than those on unmodified and laminin modified PBS foams

Bone Formation from Porcine Dental Germ Stem Cells on Surface Modified Polybutylene Succinate Scaffolds

Designing and providing a scaffold are very important for the cells in tissue engineering. Polybutylene succinate (PBS) has high potential as a scaffold for bone regeneration due to its capacity in cell proliferation and differentiation. Also, stem cells from 3rd molar tooth germs were favoured in this study due to their developmentally and replicatively immature nature. In this study, porcine dental germ stem cells (pDGSCs) seeded PBS scaffolds were used to investigate the effects of surface modification with fibronectin or laminin on these scaffolds to improve cell attachment, proliferation, and osteogenic differentiation for tissue engineering applications. The osteogenic potentials of pDGSCs on these modified and unmodified foams were examined to heal bone defects and the effects of fibronectin or laminin modified PBS scaffolds on pDGSC differentiation into bone were compared for the first time. For this study, MTS assay was used to assess the cytotoxic effects of modified and unmodified surfaces. For the characterization of pDGSCs, flow cytometry analysis was carried out. Besides, alkaline phosphatase (ALP) assay, von Kossa staining, real-time PCR, CM-Dil, and immunostaining were applied to analyze osteogenic potentials of pDGSCs. The results of these studies demonstrated that pDGSCs were differentiated into osteogenic cells on fibronectin modified PBS foams better than those on unmodified and laminin modified PBS foams

Collagen scaffolds with in situ-grown calcium phosphate for osteogenic differentiation of Wharton's jelly and menstrual blood stem cells

The aim of this research was to investigate the osteogenic differentiation potential of non-invasively obtained human stem cells on collagen nanocomposite scaffolds with in situ-grown calcium phosphate crystals. The foams had 70% porosity and pore sizes varying in the range 50-200 mu m. The elastic modulus and compressive strength of the calcium phosphate containing collagen scaffolds were determined to be 234.5 kPa and 127.1 kPa, respectively, prior to in vitro studies. Mesenchymal stem cells (MSCs) obtained from Wharton's jelly and menstrual blood were seeded on the collagen scaffolds and proliferation and osteogenic differentiation capacities of these cells from two different sources were compared. The cells on the composite scaffold showed the highest alkaline phosphatase activity compared to the controls, cells on tissue culture polystyrene and cells on collagen scaffolds without in situ-formed calcium phosphate. MSCs isolated from both Wharton's jelly and menstrual blood showed a significant level of osteogenic activity, but those from Wharton's jelly performed better. In this study it was shown that collagen nanocomposite scaffolds seeded with cells obtained non-invasively from human tissues could represent a potential construct to be used in bone tissue engineering. Copyright (C) 2012 John Wiley & Sons, Ltd

Hyaluronic Acid/Chitosan Coacervate-Based Scaffolds

Chitosan-chloride (CHI) and sodium hyaluronate (HA), two semiflexible biopolymers, self-assemble to form nonstoichiometric coacervates. The effect of counterions was briefly investigated by preparing HA/CHI coacervates in either CaCl₂ or NaCl solutions to find only a small difference in their tendency to coacervate. Higher water content in coacervates within CaCl₂ was attributed to the chaotropic nature of Ca²⁺ ions. This effect was also evidenced with smaller pore sizes for coacervates in NaCl. Besides, for coacervation of chitosan-glutamate (CHI-G) with HA, dynamic light scattering at different charge ratios indicated a wider coacervation region for the HA/CHI-G pair than the HA/CHI. This was attributed to the chaotropic and “soft” ion nature of glutamate compared to chloride as a counterion of chitosan. Positive zeta potential values for both coacervate suspensions were explained by the contribution of charge mismatch, chain semiflexibility, and intra- and intercomplex disproportionation. Finally, HA/CHI coacervates were used to encapsulate bone marrow stem cells. While cell viabilities in HA/CHI coacervates were remarkable up to 21 days, their well-spread morphology has proved that HA/CHI coacervates are promising scaffolds for cartilage tissue engineering

Polybutylene Succinate (PBS) - Polycaprolactone (PCL) Blends Compatibilized with Poly(ethylene oxide)-block-poly( propylene oxide)-block-poly(ethylene oxide) (PEO-PPO-PEO) Copolymer for Biomaterial Applications

This study reports the preparation and characterization of Polybutylene Succinate (PBS)-Polycaprolactone (PCL) melt blends (10-40 wt.% PCL) in the presence of a compatibilizer, in order to explore their potential use as a biomaterial. The thermal transitions, as well as the crystallinity of the polymer blends were analyzed by Differential Scanning Calorimetry, the thermomechanical properties were analyzed via Dynamic Mechanical Analysis and phase morphologies were characterized by Scanning Electron Microscopy. Degradation profiles of the blends were analyzed in PBS buffer solution at pH 7.4 at 37 degrees C via pH measurements. Cytotoxicity of the PBS/PCL films were tested by MTS assay

An in vitro human skeletal muscle model: coculture of myotubes, neuron-like cells, and the capillary network

This study reports the generation of a new human muscle tissue equivalent from skeletal muscle-derived stem cells and human umbilical vein endothelial cells (HUVECs). Skeletal muscle stem cells were isolated by the preplate technique and differentiated into neuron-like cells that were positive for neuronal beta-tubulin3 and nestin and negative for the astrocyte marker glial fibrillary acidic protein (GFAP). Coculture of skeletal muscle stem cells with the HUVECs under optimized fetal bovine serum and media conditions resulted in formation of a capillary network among the multinucleated myotubes. The neuron-like cells derived from the human skeletal muscle stem cells were seeded onto vascularized myotubes to obtain the neuromuscular junctions in the coculture. At the end of 24 h of coculture, the neuron-like cells were found to be in association with the myotubes. This model represents a novel complex in vitro human skeletal muscle model containing advanced capillary networks and interacting myotubes and neurons, and it can be used for in vitro drug testing or for skeletal muscle regeneration either through application of cellular therapy or cell-laden tissue-engineered muscle constructs

An in vitro human skeletal muscle model: coculture of myotubes,neuron-like cells, and the capillary network

This study reports the generation of a new human muscle tissue equivalent from skeletal muscle-derived stem cells and human umbilical vein endothelial cells (HUVECs). Skeletal muscle stem cells were isolated by the preplate technique and differentiated into neuron-like cells that were positive for neuronal beta-tubulin3 and nestin and negative for the astrocyte marker glial fibrillary acidic protein (GFAP). Coculture of skeletal muscle stem cells with the HUVECs under optimized fetal bovine serum and media conditions resulted in formation of a capillary network among the multinucleated myotubes. The neuron-like cells derived from the human skeletal muscle stem cells were seeded onto vascularized myotubes to obtain the neuromuscular junctions in the coculture. At the end of 24 h of coculture, the neuron-like cells were found to be in association with the myotubes. This model represents a novel complex in vitro human skeletal muscle model containing advanced capillary networks and interacting myotubes and neurons, and it can be used for in vitro drug testing or for skeletal muscle regeneration either through application of cellular therapy or cell-laden tissue-engineered muscle constructs