Hydrothermal Fabrication of Highly Porous Titanium Bio-Scaffold with a Load-Bearable Property.
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ABSTRACT:
SUBMITTER: Lee H
PROVIDER: S-EPMC5551769 | biostudies-other | 2017 Jun
REPOSITORIES: biostudies-other
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Project description:Electrospinning has been widely used to fabricate fibrous scaffolds for cartilage tissue engineering, but their small pores severely restrict cell infiltration, resulting in an uneven distribution of cells across the scaffold, particularly in three-dimensional designs. If bio-electrospraying is applied, direct chondrocyte incorporation into the fibers during electrospinning may be a solution. However, before this approach can be effectively employed, it is critical to identify whether chondrocytes are adversely affected. Several electrospraying operating settings were tested to determine their effect on the survival and function of an immortalized human chondrocyte cell line. These chondrocytes survived through an electric field formed by low needle-to-collector distances and low voltage. No differences in chondrocyte viability, morphology, gene expression, or proliferation were found. Preliminary data of the combination of electrospraying and polymer electrospinning disclosed that chondrocyte integration was feasible using an alternated approach. The overall increase in chondrocyte viability over time indicated that the embedded cells retained their proliferative capacity. Besides the cell line, primary chondrocytes were also electrosprayed under the previously optimized operational conditions, revealing the higher sensitivity degree of these cells. Still, their post-electrosprayed viability remained considerably high. The data reported here further suggest that bio-electrospraying under the optimal operational conditions might be a promising alternative to the existent cell seeding techniques, promoting not only cells safe delivery to the scaffold, but also the development of cellularized cartilage tissue constructs.
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Project description:BackgroundDirect attachment of tendons to metallic implants is important in orthopedics. Tissue integration depends on scaffold microstructure and composition. This study evaluated the effect of pore size of titanium on the viability and function of fibroblasts and tenocytes in a dynamic bioreactor.MethodsStandardized Ti porous cylinders with 3 pore sizes (400, 700, and 1000 μm) were seeded with fibroblasts or tenocytes (4500 cells/μL) in silicon tubes. Cells were analyzed via alamarBlue (AB) assay in addition to scanning electron microscopy at day 7 (fibroblasts) or day 8 (tenocytes) and day 15. AB functions as a cell health indicator where functional living cells reduce the resazurin dye (blue) in the solution to resorufin (pink), and cell viability can be quantified via spectroscopy.ResultsAt day 7, fibroblasts cultured on all sizes reduced AB, with significant differences noted between 400 vs 1000 μm (P = .013) and 700 vs 1000 μm (P = .001). At day 15, fibroblasts reduced AB on all sizes with a significant difference noted between 700 vs 1000 μm (P = .004). Fibroblasts on all 3 pore sizes increased AB reduction from day 7 to day 15. Tenocytes reduced AB with significant differences between the 400 vs 700 μm (P = .049) and the 400 vs 1000 μm pore sizes at day 8. In contrast, tenocyte reduction of AB decreased from day 8 to day 15. Scanning electron microscopy performed on fibroblast cylinders showed fibroblasts reached the surface of the cylinders, confirming interconnectivity.ConclusionsWhile both fibroblasts and tenocytes penetrated the pores, fibroblasts preferred larger size, whereas tenocytes favored smaller size. Results are encouraging since soft-tissue attachment to a metallic scaffold is difficult but clinically desirable. Future studies could be performed in an in vivo animal model.
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