A device to apply user-specified strains to biomaterials in culture.
An apparatus was developed to apply user-specified displacements to biomaterial samples in culture. The device allowed cyclic waveforms of bandwidth 0 Hz to 20 Hz to be applied under physiologic thermal (37.5 degrees C) and [CO2] (5%) conditions. For a 0 Hz to 20 Hz bandwidth signal similar in shape to a ventricular pressure waveform, the mean displacement error was 0.26% of the full-scale output. The maximum overshoot was 0.700%. Environmental system evaluation tests demonstrated a specimen cartridge temperature of 37.20 +/- 0.15 degrees C during cyclic loading and 37.23 +/- 0.21 degrees C during static conditions. [CO2] was 5.29 +/- 0.54% during cyclic loading and 5.25 +/- 0.61% during static conditions. Laminar flow applied at the loading rod entrances to the specimen cartridge ensured the sample remained sterile during testing. As a preliminary evaluation, polyurethane samples were seeded with fetal foreskin fibroblasts and subject to intermittent cyclic displacements. Results demonstrated enhanced cell proliferation and increased [PGE2] for samples subjected to 10% strain compared with unstrained controls. A next step will be to evaluate cell response sensitivity to strain magnitude, duration, direction, and frequency. The long-term intent is to establish mechanical loading configurations that induce acceptable or adaptation-inducing responses for use in implant design and tissue engineering applications.
Mitchell
S B
SB
Department of Bioengineering, University of Washington, Seattle 98195, USA.
Sanders
J E
JE
Garbini
J L
JL
Schuessler
P K
PK
D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D018929:Cell Culture Techniques / Q000295:instrumentation* / Q000379:methods*; D002455:Cell Division / Q000502:physiology; D015232:Dinoprostone / Q000378:metabolism; D004867:Equipment Design; D005347:Fibroblasts / Q000502:physiology; D006801:Humans; D008567:Membranes, Artificial; D009038:Motion; D012867:Skin / Q000196:embryology; D013314:Stress, Mechanical; D013696:Temperature; D016474:Weight-Bearing / Q000502:physiology
D008567:Membranes, Artificial; D002245:Carbon Dioxide; D015232:Dinoprostone