A biohybrid artificial lung prototype with active mixing of endothelialized microporous hollow fibers.
Acute respiratory distress syndrome (ARDS) affects nearly 150,000 patients per year in the US, and is associated with high mortality ( approximately 40%) and suboptimal options for patient care. Mechanical ventilation and extracorporeal membrane oxygenation are limited to short-term use due to ventilator-induced lung injury and poor biocompatibility, respectively. In this report, we describe the development of a biohybrid lung prototype, employing a rotating endothelialized microporous hollow fiber (MHF) bundle to improve blood biocompatibility while MHF mixing could contribute to gas transfer efficiency. MHFs were surface modified with radio frequency glow discharge (RFGD) and protein adsorption to promote endothelial cell (EC) attachment and growth. The MHF bundles were placed in the biohybrid lung prototype and rotated up to 1,500 revolutions per minute (rpm) using speed ramping protocols to condition ECs to remain adherent on the fibers. Oxygen transfer, thrombotic deposition, and EC p-selectin expression were evaluated as indicators of biohybrid lung functionality and biocompatibility. A fixed aliquot of blood in contact with MHF bundles rotated at either 250 or 750 rpm reached saturating pO(2) levels more quickly with increased rpm, supporting the concept that fiber rotation would positively contribute to oxygen transfer. The presence of ECs had no effect on the rate of oxygen transfer at lower fiber rpm, but did provide some resistance with increased rpm when the overall rate of mass transfer was higher due to active mixing. RFGD followed by fibronectin adsorption on MHFs facilitated near confluent EC coverage with minimal p-selectin expression under both normoxic and hyperoxic conditions. Indeed, even subconfluent EC coverage on MHFs significantly reduced thrombotic deposition adding further support that endothelialization enhances, blood biocompatibility. Overall these findings demonstrate a proof-of-concept that a rotating endothelialized MHF bundle enhances gas transfer and biocompatibility, potentially producing safer, more efficient artificial lungs.
Polk
Alexa A
AA
The McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pennsylvania 15213, USA.
Maul
Timothy M
TM
McKeel
Daniel T
DT
Snyder
Trevor A
TA
Lehocky
Craig A
CA
Pitt
Bruce
B
Stolz
Donna Beer
DB
Federspiel
William J
WJ
Wagner
William R
WR
D001187:Artificial Organs; D001672:Biocompatible Materials; D001774:Blood Chemical Analysis; D042783:Endothelial Cells / Q000502:physiology*; D006801:Humans; D008168:Lung; D019016:Mineral Fibers; D010100:Oxygen / Q000032:analysis; D010313:Partial Pressure
D001672:Biocompatible Materials; D019016:Mineral Fibers; D010100:Oxygen