Development of a System for the Performance and Evaluation of Mechanical Conditioning on Tissue Engineered Vascular Grafts
Tissue Engineering can become a reliable alternative to current treatments for cardiovascular disease. In order for safe and durable tissue-engineered constructs to be produced and implanted, the development of a system for conditioning and evaluating the structures is required.
The aim of the present study was to design and construct a system which will be capable of: (a) performing fatigue testing by applying physiological pressure profiles with supraphysiological pulse rates (up to 10 Hz) on tissue-engineered vascular grafts in order to deliver a given amount of pulses in a shorter time and (b) monitoring the diameter of a blood vessel in order to calculate the compliance and the distensibility of the vessel in order to adequately evaluate the effects of the conditioning phase.
It was hypothesized that a system composed by a linear motor that applies adjustable pressure to the circulating cell culture medium through an elastic membrane could successfully create a physiological pressure profile with adjustable frequency. In addition, the use of an optical micrometer can enable the accurate measurement of the diameter of the vessel without a risk of contamination, through a transparent chamber.
Physiological pressure (pulses of 80 and 120 mmHg for the diastolic and the systolic phase respectively) was achieved for frequencies up to 5 Hz. In the case of 10 Hz, only amplitude of 14 mmHg was possible. The optical micrometer could successfully measure the diameter of native and acellularized blood vessels without disrupting the sterility of the environment.
KeywordsPressure Pulse Vascular Graft Mechanical Conditioning Engineer Heart Valve Tissue Heart Valve Tissue
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