Pressure induced lung injury in a novel in vitro model of the alveolar interface: protective effect of dexamethasone.

Purpose: The lungs of infants born with congenital diaphragmatic hernia suffer from immaturity as well as the short and long term consequences of ventilator-induced lung injury, including chronic lung disease. Antenatal and postnatal steroids are among current strategies promoted to treat premature lungs and limit long term morbidity. Although studied in whole-animal models, insight into ventilator-induced injury at the alveolar-capillary interface as well as the benefits of steroids, remains limited.

A multiphase fluidic platform for studying ventilator-induced injury of the pulmonary epithelial barrier.

Mechanical ventilation has been a critical part of basic life support for many years, with almost one-third of all patients in the intensive care unit requiring the aid. However studies over the past two decades have indicated that ventilators have the potential to cause or aggravate pulmonary injury. The lung with its anatomically complex architecture and unique amalgam of cell types and interfaces is very difficult to replicate in vitro.

Engineering an artificial alveolar-capillary membrane: a novel continuously perfused model within microchannels.

Introduction: Pulmonary hypoplasia is a condition of the newborn that is characterized by underdeveloped lungs and poor outcome. One strategy in the treatment of patients with hypoplasia is to augment underdeveloped lungs using biocompatible artificial lung tissue. However, one central challenge in current pulmonary tissue engineering efforts remains the development of a stable bio-mimetic alveolar-capillary membrane.

An open-access microfluidic model for lung-specific functional studies at an air-liquid interface.

In an effort to improve the physiologic relevance of existing in vitro models for alveolar cells, we present a microfluidic platform which provides an air-interface in a dynamic system combining microfluidic and suspended membrane culture systems. Such a system provides the ability to manipulate multiple parameters on a single platform along with ease in cell seeding and manipulation. The current study presents a comparison of the efficacy of the hybrid system with conventional platforms using assays analyzing the maintenance of function and integrity of A549 alveolar epithelial cell monolayer cultures.

Characterization of pulmonary cell growth parameters in a continuous perfusion microfluidic environment.

In vitro models of the alveolo-pulmonary barrier consist of microvascular endothelial cells and alveolar epithelial cells cultured on opposing sides of synthetic porous membranes. However, these simple models do not reflect the physiological microenvironment of pulmonary cells, wherein cells are exposed to a complex milieu of mechanical and soluble stimuli. In this report, we studied alveolar epithelial (A549) and microvascular endothelial (HMEC-1) cells within varying microfluidic environments as a first step towards building a microfluidic analog of the gas-exchange interface.

Micropatterned surfaces for controlling cell adhesion and rolling under flow.

Cell adhesion and rolling on the vascular wall is critical to both inflammation and thrombosis. In this study we demonstrate the feasibility of using microfluidic patterning for controlling cell adhesion and rolling under physiological flow conditions. By controlling the width of the lines (50-1000 microm) and the spacing between them (50-100 microm) we were able to fabricate surfaces with well-defined patterns of adhesion molecules.