ABSTRACT
Objective To simulate the blood flow features of the susceptible sites of atherosclerosis in vitro.The cell micro-patterning is to be obtained on the bottom of channel for the information about single cell or cell groups.Methods Poly-dimethylsiloxane(PDMS) flow channel and PDMS stamp were fabricated by soft lithography.Fibronectin pattern was formed on chamber bottom by micro-contact printing method and cells selectively attached on fibronectin pattern.Results The PDMS-patterned chamber that possessed favorable optical property and the PDMS stamps with different sizes were obtained.Cells attached on fibronectin pattern presented square array.Conclusion The fabricated methods are quick and simple.The chamber could be used for the advanced real-time investigation of cell mechanical behavior in vitro.
ABSTRACT
The effects of the gravitational potential energy change (GPEC) and the thermal stress on finger microvascular responses were studied by laser Doppler and ultrasonic Doppler flowmetry. Seven healthy male subjects, aged 21 to 31 yrs, participated in the experiment after giving their informed consent. The hand was moved upward (about 60 cm) or downward (about 55 cm) from the heart level to change the vascular transmural pressure of the finger (GPEC) . Sensors of laser Doppler and ultrasonic Doppler flowmeters were attached to the lateral side of the first finger and the skin surface over the radial artery, respectively. Experimental room temperature was maintained at 24°C. Laser Doppler flow (LDF) was decreased at an elevated and lowered arm position. The pulsatile component of LDF, evaluated by the difference between systolic and diastolic LDF, increased when the arm was elevated, but it showed no significant changes when the arm was lowered. Mean blood velocity (MBV) and diastolic blood velocity (DBV) of radial artery decreased when the arm was elevated, whereas the pulsatile blood velocity (PBV), evaluated by the difference between systolic blood velocity (SBV) and DBV, were increased. At the lowered arm position, SBV and PBV decreased significantly, but DBV showed no significant changes. The thermal stress (43°C, 10 min) increased the PBV when the arm was elevated, but the PBV diminished the decreasing rate when the arm was lowered.<BR>These results suggest that the measurements used may be useful for the analysis of arteriolar compliance and microvascular response to the change of transmural pressure pro-duced by the gravitational potential energy change.