A Novel Dynamic 3-Dimensional Construct for Respiratory Tissue Engineering

Abstract

Tissue engineering of airway tissues poses many complex challenges. As tissue form is determined by function and vice versa, it is necessary to consider mechanical and physiological constraints in conjunction with standard biologic and biochemical factors when culturing tissues in vitro. This study involved the development and validation of a novel 3-dimensional (3-D) construct with the capacity to periodically expose a cell scaffold to air and medium at application of physiologic strain rates. The ultimate objective was to mimic respiratory conditions experienced by airway tissues during breathing whilst ensuring compatibility with proven cell culture techniques. The Biaxx design consists of an elastomeric porous synthetic scaffold integrated with a unique biopolymer coupling unit which engages with an IAXSYS bioreactor actuator. Uniform biaxial strain was imparted by the coupling unit whilst simultaneously creating a periodic air-liquid interface. Biaxx scaffolds with and without a coating of particulate 45S5 bioglass were employed in an assay to assess cell attachment and proliferation whilst subject to periodic strain. Physiologic lung tissue strain of 5-15% was achieved for over 200,000 cycles at 0.2Hz. Preliminary biological studies with H460 human lung carcinoma cells confirmed cell attachment, growth and proliferation on this promising construct.