Oscillatory Flow Effects on Rat Aortic Smooth Muscle Cells

Inhaltsangabe:Abstract:

A cell culture System to mimic the circumferential expansion of the arterial wall was supplemented with a flow control System for model enhancement. The given System imposed uniaxial sinusoidal stretch (1 Hz) with a 10 % elongation to an elastic silicone substrate upon which rat aortic smooth muscle cells were cultured. Occurring fluid motion during a stretch experiment caused oscillating shear stress upon the Gell layer of approximately 0.6 dynes/cm2 (60 x 10-3 N/m2) and was controlled by the newly added oscillatory flow System.

Experiments were performed and investigated at 0, 4, and 24 hours. Morphological observations correlated with the results obtained by the initial stretch experiments. A final median angle of orientation of 60° - 70° from the axis of stretch was observed. Both control cultures remained randomly oriented throughout all experiments. Inhibition of cell proliferation alter 4 hours of cyclic stretch, observed by Karen J. Schnetzer could not be confirmed. However, growth related results did correspond to the preceding study in a qualitative manner. Influences of oscillatory flow an SMC growth and morphology were not different to the steady-stretch control. Analysis of results confirmed the assumption made for the earlier culture system, that effects of oscillatory fluid motion occurring during the cyclic stretch experiment could be neglected.

Inhaltsverzeichnis:Table of Contents:

AcknowledgmentsV

List of FiguresIX

List of TablesXI

List of SymbolsXIII

1.Introduction1

2.Background and Literature Review3

2.1Arterial Anatomy4

2.2Arterial Physiology6

2.3Arterial Mechanics7

2.3.1Tensile Stress and Arterial Wall Deformation7

2.3.2Shear Stress8

2.4Arterial Pathology10

2.4.1Atherosclerosis10

2.4.2Hypertension12

2.4.3Smooth Muscle Cells in Arterial Disease12

2.5Cell Culture Models of Arterial Mechanics13

2.5.1Shear Models14

2.5.2Stretch Models14

3.Materials and Methods17

3.1Stretch Chamber17

3.1.1Demands on the Stretch System18

3.1.2Stretch Chamber Design19

3.2Flow Chamber20

3.2.1Mathematical Description of the Flow22

3.2.2Demands on the Flow Chamber27

3.2.3Flow Chamber Design27

3.3Elastic Substrate31

3.3.1Silicone Membranes31

3.3.2Extracellular Matrix33

3.4Cell Culture35

3.4.1Smooth Muscle Cells36

3.4.2Culture. Procedures37

3.5Experimental Set-Up40

3.5.1Equipment Preparation40

3.5.2Substrate Preparation41

3.5.3Cell Seeding Method43

3.5.4Stretch and Flow Chamber [¿]