May the Force Be with You

Placental transfusion: may the "force" be with the baby

Placental transfusion results in a significant decrease in the risk of death for extremely preterm infants. With immediate cord clamping (ICC), these infants can leave up to one-half of their normal circulating in utero blood volume in the placenta. Extremely preterm infants are at highest risk of harm from ICC yet are currently the most likely to receive ICC. Receiving a placenta transfusion provides infants with life-saving components and enhanced perfusion. We present some lesser-known but important effects of placental transfusion. New research reveals that enhanced vascular perfusion causes an organ's endothelial cells to release angiocrine responses to guide essential functions. High progesterone levels and pulmonary artery pressure in the first few hours of life assist with neonatal adaptation. We propose that lack of essential blood volume may be a major factor contributing to inflammation, morbidities, and mortality that preterm infants frequently encounter.

3D-printable supramolecular hydrogels with shear-thinning property: fabricating strength tunable bioink via dual crosslinking

3-dimensional (3D) bioprinting technology provides promising strategy in the fabrication of artificial tissues and organs. As the fundamental element in bioprinting process, preparation of bioink with ideal mechanical properties without sacrifice of biocompatibility is a great challenge. In this study, a supramolecular hydrogel-based bioink is prepared by polyethylene glycol (PEG) grafted chitosan, α-cyclodextrin (α-CD) and gelatin. It has a primary crosslinking structure through the aggregation of the pseudo-polyrotaxane-like side chains, which are formed from the host-guest interactions between α-CD and PEG side chain. Apparent viscosity measurement shows the shear-shinning property of this bioink, which might be due to the reversibility of the physical crosslinking. Moreover, with β-glycerophosphate at different concentrations as the secondary crosslinking agent, the printed constructs demonstrate different Young's modulus (p < 0.001). They could also maintain the Young's modulus in cell culture condition for at least 21 days (p < 0.05). By co-culturing each component with fibroblasts, CCK-8 assay demonstrate cellular viability is higher than 80%. After bioprinting and culturing, immunofluorescence staining with quantification indicate the expression of Ki-67, Paxillin, and N-cadherin is higher in day 14 than those in day 3 (p < 0.05). Oil red O and Nissl body specific staining reflect strength tunable bioink may have impact on the cell fate of mesenchymal stem cells (p < 0.05). This work might provide new idea for advanced bioink in the application of re-establishing complicated tissues and organs.

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Supramolecular bioink demonstrates good shear-shinning property.

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Dual crosslinking provides the bioink with tunable strength.

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Tunable strength facilitates stem cells lineage differentiation.