Advanced bioreactor for ligament tissue engineering

Abstract

Advanced bioreactors are essential for meeting the complex requirements of in vitro ligament tissue engineering. A novel bioreactor system for the functional tissue engineering of ligaments, combined with culture medium perfusion over long periods of time and capability to apply cyclic mechanical loadings to three-dimensional scaffolds independently housed in six chambers, was developed. Well-controlled mechanical stimulations (resolution of <0.01mm for translational and <0.1 for rotational stress ) could be applied to the growing tissue, especially to tissue engineered anterior cruciate ligament (ACL). The novel bioreactor could apply independent tensile/compressive stresses along the same axis and two-way torsions stimulation at the same time. A new type of scaffold relaxation compensation device which could adapt to a range of scaffold length of the changes and be able to realize independently online compensation was designed. The movement control strategies were proposed. This bioreactor is suitable for the tissue engineering of the human knee joint ACLs in both research and clinical applications.

Design and Improvement on a Stress Loading Device for Ligament Tissue Engineering

“…Much different cycles with varying strain regimes can be programmed and run for the duration of an experiment. The typical motion control modes were shown in [5].…”

“…For example, Bose® BioDynamic™ test instrument is a commercially available system with capability to apply uniaxial tensile or compressive loadings. The bioreactors for the functional tissue engineering of the human knee joint anterior cruciate ligament (ACL), as in [2][3][4][5], were designed to meet the mechanical loading needs of independent tensile and two-way torsion stress along the same axial at the same time. The translational and rotational motions are carried out through ball screw-nut pair and gear trains, driven by 2 high-torque stepper motors.…”

Design of Bioreactor Control System for Ligament Tissue Engineering

“…The culture medium recirculation control subsystem is consisted of a multi-channel peristaltic pump, twelve check valves, six scaffold chambers, and medium biochemical factors control subsystem. The medium biochemical factors control subsystem was built to control the gas concentration of O 2 , CO 2 , and chemist components for all six scaffold chambers through platinumcured silicon tubing gas exchanges, and keep the culture medium fresh (As described in [4] ).…”

“…In this work, the coordinated control strategies for displacement and strain were proposed, basing on gateway control method, using a novel online length relaxation compensation device of scaffold. The improved relaxation compensation device was developed, basing on the designed relaxation compensation device [4]. The remarkable advantage of the novel device is its ability to adjust the scaffold length continuously.…”

“…Importantly, none of the known biochemical regulatory factors and mechanical stimulation intensity has been shown in vitro [3,4]. In this study, we describe the design of the control and measurement system of an advanced computer controlled annular bioreactor, which allows controlling complex concurrent multi-dimensional strain and simultaneous perfusion in a closed aseptic bioreactor equipped with the relaxation compensation function for scaffolds independently housed in six chambers.…”