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ABSTRACT: Since pheochromocytoma 12 (PC12) cells have the ability of neuronal differentiation upon nerve growth factor (NGF) treatment, they are a good model for studying the neuronal differentiation. Establishing a strong adhesion of PC12 cells to the culture substrate may increase neuronal differentiation, and the use of L-3,4-dihydroxyphenylalanine (L-DOPA), which is responsible for the adhesive property of mussel adhesive proteins (MAPs), is a feasible strategy for such strong adhesion. We hypothesized that a polydopamine-modified surface can promote PC12 cell adhesion and subsequent neuronal differentiation. We examined whether polydopamine-modified surface promotes PC12 cell adhesion, and further evaluated the neuronal differentiation of these cells. The polydopamine modification enhanced the cell adhesion and viability, and also promoted the neuronal differentiation of NGF-stimulated PC12 cells, as evidenced by the elongation of neurites and expression of neuronal differentiation markers, by increasing the activation of NGF/Trk-Rho GTPase signal pathway. Our findings will help develop an improved strategy for functionalizing biomaterial substrates for less-adhesive cells including neural cells.
Biochemical and Biophysical Research Communications 12/2012; · 2.48 Impact Factor
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ABSTRACT: Bone morphogenetic protein-2 (BMP-2) is known to induce both osteogenic and chondrogenic commitment of human mesenchymal stem cells (hMSCs). However, factors influencing BMP-2-dependent chondrogenic and osteogenic differentiation have not been investigated. In this study, we demonstrated that extracellular microenvironments, in the form of cell-derived matrices, play important roles in determining the specific lineage commitment of hMSCs in the presence of BMP-2. Extracellular matrices (ECMs) derived from osteoblasts and chondrocytes were utilized to regulate cell differentiation. Osteogenic and chondrogenic differentiation of hMSCs cultured on the two different cell-derived ECMs were assessed by quantitative real-time polymerase chain reaction, immunocytochemistry, and western blot analysis. To minimize the effects of the cell-adhesion proteins contained in serum on the ECMs, hMSCs were cultured in serum-free osteogenic or chondrogenic differentiation medium. Fibronectin-, collagen type I-, or collagen type II-coated substrates were utilized as ECM controls. The ECM specific to each cell type promoted lineage-specific commitment of hMSCs in the presence of BMP-2, i.e., osteoblast- and chondrocyte-derived ECM promoted osteogenic and chondrogenic commitment, respectively. Therefore, cell-specific ECMs are capable of modulating the BMP-2-induced osteogenic and chondrogenic differentiation of hMSCs.
Tissue Engineering Part A 10/2012; · 4.64 Impact Factor
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ABSTRACT: Bone morphogenetic protein-2 (BMP-2) can induce bone generation in vivo. Although many studies have demonstrated an increased quantity of regenerated bone after the delivery of BMP-2 using various carriers, little is known about the effect of the carrier type on the quality of the regenerated bone. In this study, we compared the quality of regenerated bone when BMP-2 was delivered with either β-tricalcium phosphate (β-TCP) or heparin-conjugated fibrin (HCF), both of which are shown to be excellent carriers for BMP-2. The profile of the release of BMP-2 was not significantly different between the delivery carriers. However, the alkaline phosphate activity of cultured osteoblasts was significantly higher when BMP-2 was delivered using HCF than when BMP-2 was delivered using β-TCP. To evaluate the quality of the regenerated bone, both types of BMP-2 carriers were implanted into critical-sized calvarial defects in mice. Eight weeks after implantation, the regenerated bone was examined by histomorphometry. Importantly, the treatment using HCF + BMP-2 and β-TCP + BMP-2 resulted in similar bone formation areas. However, the treatment using HCF + BMP-2 resulted in significantly higher bone density than the treatment using β-TCP + BMP-2. This study shows that a BMP-2 delivery carrier can modulate the quality of bone regenerated via BMP-2 delivery.
Artificial Organs 02/2012; 36(7):642-7. · 2.00 Impact Factor
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ABSTRACT: Regeneration of volume-stable adipose tissue is required for treatment of soft-tissue loss due to cancer, trauma, burns and for correctional cosmetic surgery. In this study, we hypothesized that transplantation of human adipose-derived stromal cells (hADSCs) using polycaprolactone (PCL) scaffolds fabricated with a solid free-form fabrication method would better maintain the volume of regenerated adipose tissues, as compared with the use of fibrin gel. Six weeks after implantation into the dorsal subcutaneous pockets of athymic mice, the volumes and adipose tissue areas of hADSC-PCL scaffold implants were significantly larger than those of hADSC-fibrin implants. In addition, the mRNA expression of adipogenic genes was more extensive in the hADSC-PCL scaffold implants.
Annals of plastic surgery 01/2012; · 1.29 Impact Factor
