Effect of perfusion flow rate on tissue oxygenation in newborn piglets during cardiopulmonary bypass

Bio-inspired engineering of a perfusion culture platform for guided three-dimensional nerve cell growth and differentiation

Collagen provides a promising environment for 3D nerve cell culture; however, the function of perfusion culture and cell-growth guidance is difficult to integrate into such an environment to promote cell growth. In this paper, we develop a bio-inspired design method for constructing a perfusion culture platform for guided nerve cell growth and differentiation in collagen. Based on the anatomical structure of peripheral neural tissue, a biomimetic porous structure (BPS) is fabricated by two-photon polymerization of IP-Visio. The micro-capillary effect is then utilized to facilitate the self-assembly of cell encapsulated collagen into the BPS. 3D perfusion culture can be rapidly implemented by inserting the cell-filled BPS into a pipette tip connected with syringe pumps. Furthermore, we investigate the nerve cell behavior in the BPS. 7-channel aligned cellular structures surrounded with a Schwann cell layer can be stably formed after a long-time perfusion culture. Differentiation of PC12 cells and mouse neural stem cells shows 3D neurite outgrowth alignment and elongation in collagen. The calcium activities of differentiated PC12 cells are visualized for confirming the preliminary formation of cell function. These results demonstrate that the proposed bio-inspired 3D cell culture platform with the advantages of miniaturization, structure complexity and perfusion has great potential for future application in the study of nerve regeneration and drug screening.

Managing the inflammatory response after cardiopulmonary bypass: review of the studies in animal models

Objective

To review studies performed in animal models that evaluated therapeutic interventions to inflammatory response and microcirculatory changes after cardiopulmonary bypass.

Methods

It was used the search strategy ("Cardiopulmonary Bypass" ^(MeSH)) and ("Microcirculation" ^(MeSH) or "Inflammation" ^(MeSH) or "Inflammation Mediators" ^(MeSH)). Repeated results, human studies, non-English language articles, reviews and studies without control were excluded.

Results

Blood filters, system miniaturization, specific primers regional perfusion, adequate flow and temperature and pharmacological therapies with anticoagulants, vasoactive drugs and anti-inflammatories reduced changes in microcirculation and inflammatory response.

Conclusion

Demonstrated efficacy in animal models establishes a perspective for evaluating these interventions in clinical practice.

Regional tissue oxygenation in preterm born infants in association with echocardiographically significant patent ductus arteriosus

OBJECTIVE

To analyze the levels of regional tissue oxygenation in preterm infants in association with echocardiographically significant patent ductus arteriosus (PDA).

STUDY DESIGN

Preterm infants with gestational age less than 32 week were enrolled before the first dose of the pharmacological treatment for the PDA. Non-invasive near-infrared spectroscopy (NIRS) technology was utilized to measure cerebral (rSO(2)-C), renal (rSO(2)-R) and mesenteric (rSO(2-M)) tissue oxygenation for approximately 60 min. Regional fractional oxygen extraction (FOE) was calculated using simultaneously measured arterial saturation (SaO(2)). We analyzed regional tissue oxygenation and oxygen extraction, hemodynamic parameters, and demographic and clinical information in association with the size of the PDA (moderate vs large).

RESULT

Among the 38 enrolled infants, the majority were diagnosed with a large (63.2%, n=24) and the rest with a moderate-sized PDA. Infants with large and moderate PDA were comparable in terms of gestational age, study age and weight, mode of delivery and hemodynamic parameters. A significantly higher proportion of infants with a moderate PDA were mechanically ventilated as compared with those with a large PDA. We found no significant differences in the rSO(2)-C and rSO(2)-R, irrespective of the type of respiratory support. However, in infants with a large PDA on continuous nasal positive airway pressure (NCPAP), the rSO(2)-M was lower and mesenteric FOE was higher than that in mechanically ventilated neonates with a large PDA, and in those with moderate PDA irrespective of the type of respiratory support.

CONCLUSION

The PDA size did not affect cerebral and renal tissue oxygenation, but the mesenteric tissue oxygenation was decreased in infants with a large PDA on NCPAP.