A Pumpless Microfluidic Neonatal Lung Assist Device for Support of Preterm Neonates in Respiratory Distress

Abstract

Premature neonates suffer from respiratory morbidity as their lungs are immature, and current supportive treatment such as mechanical ventilation or extracorporeal membrane oxygenation causes iatrogenic injuries. A non‐invasive and biomimetic concept known as the “artificial placenta” (AP) would be beneficial to overcome complications associated with the current respiratory support of preterm infants. Here, a pumpless oxygenator connected to the systemic circulation supports the lung function to relieve respiratory distress. In this paper, the first successful operation of a microfluidic, artificial placenta type neonatal lung assist device (LAD) on a newborn piglet model, which is the closest representation of preterm human infants, is demonstrated. This LAD has high oxygenation capability in both pure oxygen and room air as the sweep gas. The respiratory distress that the newborn piglet is put under during experimentation, repeatedly and over a significant duration of time, is able to be relieved. These findings indicate that this LAD has a potential application as a biomimetic artificial placenta to support the respiratory needs of preterm neonates.

Toward Development of a Higher Flow Rate Hemocompatible Biomimetic Microfluidic Blood Oxygenator

“…However, significant barriers to expanded use of ECMO technology remain, particularly associated with the complexity of the blood circuit and anticoagulant administration. In response to these challenges, microfluidic oxygenators have emerged as a compelling means to address many of the safety and efficacy-related concerns with current ECMO procedures, driven in particular by opportunities to better mimic blood flow patterns in the natural lung and thereby avoid high rates of thrombus formation and heavy reliance on anticoagulant administration [ 17 , 23 , 31 ].…”

“…Scaling of the microfluidic oxygenator technology is often considered in terms of two directions. A given blood-membrane-gas sandwich structure can be scaled vertically by stacking these sandwich structures and interconnecting them with manifolds to integrate the blood and oxygen flows, as has been described previously [ 23 , 25 , 31 ]. A principal challenge this approach faces is the need for a very large number of layers in the stack [ 33 ], resulting in complexity in the assembly process as well as large increases in the blood prime volume in manifold regions not associated with blood–gas transfer.…”

“…Early results from prototyped small-scale microfluidic oxygenator blood gas transfer in the laboratory and in initial animal experiments [ 31 , 32 ] have been promising, but progress in advancing microfluidic prototypes toward a scale large enough for large animal studies and human clinical trials has been limited. In most microfluidic designs blood flow patterns remain highly non-physiological due to limitations in the ability of photolithography-based fabrication techniques to reproduce critical aspects of the architecture of the microcirculation, including smooth, rounded channels and gradually tapered transition regions at branch points between vessels.…”

“…The second significant advance reported here is a larger scale design that supports blood flow rates up to 30 mL/min in a single microfluidic layer, with blood gas transfer testing in porcine blood demonstrating high oxygen transfer rates. Prior efforts in microfluidic oxygenators have been limited to flow rates as high as only 10 mL/min [ 31 ] within a single layer, rendering it difficult to scale devices to clinically relevant blood flows without requiring an inordinate number of layers in a stacked device. This increase to 30 mL/min represents an important step toward clinically relevant flow rates per layer that can lead to practical oxygenator designs for clinical implementation.…”

Comment on “A Pumpless Microfluidic Neonatal Lung Assist Device for Support of Preterm Neonates in Respiratory Distress”

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Very recently, Dabaghi et al operated a microfluidic, artificial placenta-type neonatal lung assist device (LAD) on a newborn piglet with respiratory distress. [1] Results from the piglet experiments revealed the effectiveness of this LAD in gas exchange without complications. The authors indicated that the LAD has a potential application as a biomimetic artificial placenta to support the respiratory needs of preterm neonates.

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