Culturing Human Primary Lung Cells at the Air-Media Interface with Magnetic Levitation

Improved methods for producing three dimensional cultures of human lung cells are needed for lung tissue engineering and drug discovery. We have cultured normal endothelial, epithelial, fibroblast, and smooth muscle human primary lung cells (ScienCell Research Laboratories) at the air-media interface using magnetic levitation, a new method for three-dimensional cell culture. Magnetic levitation relies upon a mixture of gold and magnetic iron oxide nanoparticles and biocompatible polymers to deliver magnetic nanoparticles to cells and strong magnetic fields to lift cells of the bottom of the petri dish and culture them at the air-liquid interface. It allows cells to grow in three-dimensions, which is of significant interest because, for many applications, three-dimensional culturing provides a better representation of the in vivo environment than traditional two-dimensional cell culture, and it produces tissue that is more representative of natural morphology, protein expression, and response to drugs. Cells can be cultured at the air-liquid interface, which is particularly advantageous for specialized tissue such as lung. Bright field microscopy images are used to study overall cell morphology, and we observe characteristic structures typically attributed to respective cell types, such as the formation of squamous structure for epithelial cells. The production of extracellular matrix proteins such as collagen can be detected using van Gieson's staining. The magnetic levitation method will be further developed to manipulate tissue shape in mono and co-cultures of lung cells. (Funded by NSF Grant# IIP 0945954)