Effect of Optimized Concentrations of Basic Fibroblast Growth Factor and Epidermal Growth Factor on Proliferation of Fibroblasts and Expression of Collagen: Related to Pelvic Floor Tissue Regeneration / 中华医学杂志(英文版)

Background@#Fibroblasts were the main seed cells in the studies of tissue engineering of the pelvic floor ligament. Basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) were widely studied but at various concentrations. This study aimed to optimize the concentrations of combined bFGF and EGF by evaluating their effects on proliferation and collagen secretion of fibroblasts.@*Methods@#Fibroblasts were differentiated from rat adipose mesenchymal stem cells (ADSCs). Flow cytometry and immunohistochemistry were used for cell identification. The growth factors were applied at concentrations of 0, 1, 10, and 100 ng/ml as three groups: (1) bFGF alone, (2) EGF alone, and (3) bFGF mixed with EGF. Cell proliferation was evaluated by Cell Counting Kit-8 assays. Expression of Type I and III collagen (Col-I and Col-III) mRNAs was evaluated by real-time quantitative reverse transcription-polymerase chain reaction. Statistical analysis was performed with SPSS software and GraphPad Prism using one-way analysis of variance and multiple t-test.@*Results@#ADSCs were successfully isolated from rat adipose tissue as identified by expression of typical surface markers CD29, CD44, CD90, and CD45 in flow cytometry. Fibroblasts induced from ADSC, compared with ADSCs, were with higher mRNA expression levels of Col I and Col III (F = 1.29, P = 0.0390). bFGF, EGF, and the mixture of bFGF with EGF can enhanced fibroblasts proliferation, and the concentration of 10 ng/ml of the mixture of bFGF with EGF displayed most effectively (all P < 0.05). The expression levels of Col-I and Col-III mRNAs in fibroblasts displayed significant increases in the 10 ng/ml bFGF combined with EGF group (all P < 0.05).@*Conclusions@#The optimal concentration of both bFGF and EGF to promote cell proliferation and collagen expression in fibroblasts was 10 ng/ml at which fibroblasts grew faster and secreted more Type I and III collagens into the extracellular matrix, which might contribute to the stability of the pelvic floor microenvironment.

High-resolution cellular traction force recovery in two dimensional Fourier domain / 医用生物力学

Objective To develop a new set of algorithms for high-resolution cellular traction force recovery based on two-dimensional Fourier domain by addressing the ill-posed nature of classic cellular force traction recovery. Methods By exploring the inherent characteristics and rules of displacement data on the substrates and Green’s function in the Fourier domain, the phenomenon of ill-posed deconvolution arising in cellular force traction recovery was investigated and a set of self-adaptive filtering algorithms was consequently developed to remarkably restrain the high frequency noise amplification. Results The ill-posed nature of classical Fourier transform traction cytometry (FTTC) made cellular traction force recovery extremely unstable, especially for relatively dense displacement data sampling. In contrast, the proposed self-adaptive filtering algorithms based on FTTC could make cellular traction force distribution more stable and reliable, as the effect of high frequency noise in displacement field on recovery results was weakened significantly. Conclusions This new technique for cellular traction force recovery can effectively suppress the noise and therefore improve the stability of force recovery procedure and spatial resolution, which is expected to find wider application in the study of cell substrate interactions.