Quantitative evaluation of mechanical stimulation for tissue-engineered blood vessels.

Abstract

Functional small-diameter tissue engineered blood vessels (TEBVs) have been developed in-silico using biodegradable polymeric scaffolds under pulsatile perfusion. Accurate simulation of the physiological mechanical stimulation in vitro is a crucial factor in vascular engineering. However, little is known regarding the patterns of mechanical stimulation on silicone tubes. The aim of this study was to determine the optimal mechanical conditions required for inducing circumferential deformations in the silicone tubes during in vitro vascular development under pulsatile perfusion. To this end, we established a data acquisition (DAQ) system with laser micrometer and pressure transducers to evaluate the changes in the diameter of silicone tubing in response to pulsatile flow, and validated the results on cultured TEBVs. The DAQ system showed satisfactory reproducibility for measuring diameter variation in the in silico model. Furthermore, the hardness and thickness of the silicone tubes affected the mechanical conditioning on three-dimensional culture system under different working pressures, frequencies and circumferential deformations. We demonstrated a simple and reliable approach to quantify circumferential strain and deformations in order to ensure optimal mechanical stimulation of cultured TEBVs under pulsatile perfusion. Based on the results, we were able to dynamically culture dense, cellularized small-diameter TEBVs. This study highlights the importance of mechanical stimulation for vascular tissue engineering.