Pulmonary tissue engineering using dual-compartment polymer scaffolds with integrated vascular tree.
OBJECTIVE
The persistent shortage of donor organs for lung transplantation illustrates the need for new strategies in organ replacement therapy. Pulmonary tissue engineering aims at developing viable hybrid tissue for patients with chronic respiratory failure.


METHODS
Dual-chamber polymer constructs that mimic the characteristics of the pulmonary air-blood interface were fabricated by microfabrication techniques using the biocompatible polymer polydimethylsiloxane. One compartment ("vascular chamber") was designed as a capillary network to mimic the pulmonary microvasculature. The other compartment ("parenchymal chamber") was designed to permit gas exchange. Immortalized mouse lung epithelium cells (MLE-12) were cultured on the surface of polystyrene microcarrier beads. These beads were subsequently injected into the parenchymal chamber of the dual-chamber microsystems. The vascular compartment was perfused with cell culture medium in a bioreactor and the construct was maintained in culture for 1 week.


RESULTS
The microcarriers evenly distributed MLE-12 cells on the parenchymal compartment surface. Confluent cell layers were confirmed by fluorescent and electron microscopy. Adequate proliferation of MLE-12 cells within the construct was monitored via the DNA content. Viability of the cells was maintained over 1 week. Finally, cellular specificity and functional capacity in situ were demonstrated by immunostaining for proSP-B and proSP-C (alveolar epithelium), and by using MLE-12 cells transfected to overexpress green fluorescent protein.


CONCLUSIONS
We conclude that functional hybrid microsystems mimicking the basic building plan of alveolar tissue can be engineered in vitro.
Fritsche
Clemens S
CS
Laboratory for Tissue Engineering, Deutsches Herzzentrum Berlin, Cardiothoracic Surgery, Berlin, Germany. clemens_fritsche@web.de
Simsch
Oliver
O
Weinberg
Ely J
EJ
Orrick
Brian
B
Stamm
Christof
C
Kaazempur-Mofrad
Mohammad R
MR
Borenstein
Jeffrey T
JT
Hetzer
Roland
R
Vacanti
Joseph P
JP
D000818:Animals; D021522:Bioartificial Organs; D019149:Bioreactors; D015824:Blood-Air Barrier / Q000502:physiology* / Q000648:ultrastructure; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D004261:DNA Replication; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D004847:Epithelial Cells / Q000502:physiology*; D004867:Equipment Design; D005455:Fluorescent Antibody Technique; D049452:Green Fluorescent Proteins / Q000235:genetics; D036341:Intercellular Signaling Peptides and Proteins; D051379:Mice; D055617:Micro-Electrical-Mechanical Systems; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D055806:Microvessels / Q000502:physiology; D010455:Peptides / Q000378:metabolism; D011137:Polystyrenes / Q000737:chemistry; D011498:Protein Precursors / Q000378:metabolism; D011510:Proteolipids / Q000378:metabolism; D011650:Pulmonary Alveoli / Q000098:blood supply*; D037721:Pulmonary Surfactant-Associated Protein C; D013997:Time Factors; D046509:Tissue Culture Techniques / Q000295:instrumentation; D023822:Tissue Engineering / Q000295:instrumentation*; D054457:Tissue Scaffolds; D014162:Transfection
D004129:Dimethylpolysiloxanes; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D011137:Polystyrenes; D011498:Protein Precursors; D011510:Proteolipids; D037721:Pulmonary Surfactant-Associated Protein C; C489680:Sftpc protein, mouse; C105511:surfactant protein B propeptide; D049452:Green Fluorescent Proteins; C013830:baysilon