Enhancement of Cell Ingrowth, Proliferation, and Early Differentiation in a Three-Dimensional Silicon Carbide Scaffold Using Low-Intensity Pulsed Ultrasound

Abstract

Concerns over the use of autografts or allografts have necessitated the development of biomaterials for bone regeneration. Various studies have been performed to optimize the cultivation of osteogenic cells using osteoconductive porous scaffolds. The aim of this study was to evaluate the osteogenic efficiency of bone cell ingrowth, proliferation, and early differentiation in a silicon carbide (SiC) porous ceramic scaffold promoted with lowintensity pulsed ultrasound. MC3T3-E1 mouse preosteoblasts were seeded onto scaffolds and cultured for 4 and 7 days with daily of 20-min ultrasound treatment. The cells were evaluated for cell attachment, morphology, viability, ingrowth depth, volumetric proliferation, and early differentiation. After 4 and 7 days of culture and ultrasound exposure, the cell density was higher in the ultrasound-treated group compared with the sham-treated group on SiC scaffolds. The cell ingrowth depths inside the SiC scaffolds were 149.2 -27.3 mm at 1 day, 310.1 -12.6 mm for the ultrasound-treated group and 248.0 -19.7 mm for the sham control at 4 days, and 359.6 -18.5 mm for the ultrasound-treated group and 280.0 -17.7 mm for the sham control at 7 days. They were significantly increased, that is, 25% ( p = 0.0029) and 28% ( p = 0.0008) increase, respectively, with ultrasound radiation force as compared with those in sham control at 4 and 7 days postseeding. The dsDNA contents were 583.5 -19.1 ng/scaffold at 1 day, 2749.9 -99.9 ng/scaffold for the ultrasound-treated group and 2514.9 -114.7 ng/ scaffold for the sham control at 4 days, and 3582.3 -325.3 ng/scaffold for the ultrasound-treated group and 2825.7 -134.3 ng/scaffold for the sham control at 7 days. There was a significant difference in the dsDNA content between the ultrasound-and sham-treated groups at 4 and 7 days. The ultrasound-treated group with the SiC construct showed a 9% ( p = 0.00029) and 27% ( p = 0.00017) increase in the average dsDNA content at 4 and 7 days over the sham control group, respectively. Alkaline phosphatase activity was significantly increased by the treatment of ultrasound at 4 ( p = 0.012) and 7 days ( p = 0.035). These results suggested that ultrasound treatment with low-intensity acoustic energy facilitated the cellular ingrowth and enhanced the proliferation and early differentiation of osteoblasts in SiC scaffolds.

Porous three-dimensional carbon nanotube scaffolds for tissue engineering

“…Cellular infiltration inside PLGA, MWCNT and SWCNT scaffolds was assessed by image processing of confocal Z-stacks of calcein-AM stained MC3T3 cells [49]. Each individual stack was subjected to spectral-color coding steps to false color-code the cells as a function of Z-depth i.e.…”

“…Image processing to assess cellular infiltration Cellular infiltration into PLGA, MWCNT, and SWCNT scaffolds was assessed by image processing of confocal Z-stacks of calcein-AM-stained MC3T3 cells. 49 Each individual stack was subjected to spectral color-coding steps to false color code the cells as a function of Z-depth, that is, cellular infiltration. Figure 9(A-C) show infiltration of cells on PLGA, MWCNT, and SWCNT scaffolds, respectively.…”

A Comparison of 1‐ and 3.2‐MHz Low‐Intensity Pulsed Ultrasound on Osteogenesis on Porous Titanium Alloy Scaffolds: An In Vitro and In Vivo Study

“…The parameters of the in vitro porous Ti64 scaffolds are as follows: pore size of 400–500 µm, cylindrical block scaffolds 10 mm in diameter and 3 mm in height, and porosity of 65% to70% (Figure A). The parameters of the in vivo scaffolds are as follows: pore size of 800 μm to 1 mm, dimensions of 10 × 5 × 4 mm, and porosity of 80% (Figure B).…”

“…LIPUS resulted in shortening the overall bone healing time in several animal models and clinical trials . Recently, some studies have reported the effect of LIPUS on various cellular activities on porous scaffolds, such as cell proliferation, gene expression, collagen synthesis, and protein synthesis . However, these studies were all performed under the confined parameters of LIPUS.…”

Orthopedic nanoceramics

“…The enhanced mechanical properties were correlated to the microstructures of the nanoscaffold, which had ultrafine grains and increased density of solid matrix as a result of the enhanced neck growth of ceramic nanoparticles during the sintering process (Figure 3.10e vs. f). For example, in a recent study, osteogenic efficiency of bone cell ingrowth, proliferation, and early differentiation in a 3-D SiC porous ceramic scaffold with ultrasound treatment was studied [89]. 3-D porous SiC scaffolds have been fabricated and studied for potential applications in bone repair and regeneration.…”