Biology subjects

Velander, W. H.

Publications and source records attributed to Velander, W. H..

5 recordsLinked to original sources

bioRxiv2022

Mesenchymal stromal cells and alpha-1 antitrypsin have a strong synergy in modulating inflammation

Trauma, surgery, and infection can cause severe inflammation. Both dysregulated inflammation intensity and duration can lead to significant tissue injuries, organ dysfunction, mortality, and morbidity. Anti-inflammatory drugs such as steroids and immunosuppressants can dampen inflammation intensity, but they derail inflammation resolution, compromise normal immunity, and have significant adverse effects. The natural inflammation regulator mesenchymal stromal cells (MSCs) have high therapeutic potential because of their unique capabilities to mitigate inflammation intensity, enhance normal immunity, and accelerate inflammation resolution and tissue healing. Furthermore, clinical studies have shown that MSCs are safe and effective. However, they are not potent enough, alone, to completely resolve severe inflammation and injuries. One approach to boost the potency of MSCs is to combine them with synergistic agents. We hypothesized that alpha-1 antitrypsin (A1AT), a plasma protein used clinically and having an excellent safety profile, was a promising candidate for synergism. This investigation examined the efficacy and synergy of MSCs and A1AT to mitigate inflammation and to promote resolution, using in vitro cell cultures and a mouse acute lung injury and inflammation model. We found that the combination of MSCs and A1AT was much more effective than each component alone in i) modulating cytokine releases and inflammatory pathways, ii) inhibiting reactive oxygen species (ROS) and neutrophil extracellular traps (NETs) production by neutrophils, iii) enhancing phagocytosis and, iv) promoting inflammation resolution, tissue healing, and animal survival. Our results support the combined use of MSCs and A1AT for managing severe, acute inflammation.

bioengineering↗

bioRxiv2021

Isolating and Cryo-Preserving Pig Skin Cells for Single Cell RNA Sequencing Study

The Pigskin architecture and physiology are similar to these of humans. Thus, the pig model is valuable for studying skin biology and testing therapeutics for skin diseases. The single-cell RNA sequencing technology allows quantitatively analyzing cell types, cell states, signaling, and receptor-ligand interactome at single-cell resolution and at high throughput. scRNA-Seq has been used to study mouse and human skins. However, studying pigskin with scRNA-Seq is still rare. Here we described a robust method for isolating and cryo-preserving pig single cells for scRNA-Seq. We showed that pigskin could be efficiently dissociated into single cells with high cell viability using the Miltenyi Human Whole Skin Dissociation kit and the Miltenyi gentleMACS Dissociator. Also, we showed that the subsequent single cells could be cryopreserved using DMSO without causing additional cell death, cell aggregation, or changes in gene expression profiles. Using the developed protocol, we were able to identify all the major skin cell types. The protocol and results from this study will be very valuable for the skin research scientific community.

cell biology↗

bioRxiv2020

Demonstration of re-epithelialization in a bioprinted human skin equivalent wound model

ObjectiveThe development of an in vitro platform for modeling human skin injury and the re-epithelization process. ApproachA fibrin provisional matrix (FPM) was installed into a wound facsimile of a bioprinted human skin equivalent (HSE). A mixture of plasma-derived fibrinogen-containing factor XIII, fibronectin, thrombin, and macrophages (an FPM "bioink") was extruded into the wound site. The surrounding in vitro tissue culture became a source of keratinocytes to achieve wound closure by a re-epithelialization process signaled by the FPM. ResultsAn in vitro analog of wound closure and re-epithelialization by keratinocytes occurred over the FPM after a normal migration initiation at 3 days. InnovationA physiologic mixture of macrophage/fibrinogen/fibronectin that supports macrophage differentiation was applied to a mechanically wounded, bioprinted dermal tissue. We developed a transitional culture medium to mimic the changing microenvironment during the initial phases of wound healing. As a reference, we temporally compared our in vitro model with a murine skin wound healing. ConclusionThis co-culture model was shown to temporally synchronize a re-epithelization process for initiation of keratinocyte migration from a surrounding tissue and the migration process over the top of an FPM. A future study of the analogous subepithelial healing pathway is envisioned using the same in vitro bioprinted tissue study platform for co-culture of keratinocytes, melanocytes, fibroblasts, endothelial cells, and macrophages using more specialized FPMs.

bioengineering↗

bioRxiv2020

Three-Dimensional (3D) Fibronectin Nano-Array Presented on Fibrin Matrix Accelerates Mice Skin Wound Healing

Plasma fibrinogen (F1) and fibronectin (pFN) polymerize to form a fibrin clot that is both a hemostatic and provisional matrix for wound healing. About 90% of plasma F1 has a homodimeric pair of {gamma} chains ({gamma}{gamma}F1) and 10% has a heterodimeric pair of {gamma} and more acidic {gamma} chains ({gamma}{gamma}F1). We have synthesized a novel fibrin matrix exclusively from a 1:1 (molar ratio) complex of {gamma}{gamma}F1 and pFN in the presence of highly active thrombin and recombinant Factor XIII (rFXIIIa). In this matrix, the fibrin nanofibers were wrapped with periodic 200-300 nm wide pFN nanobands (termed {gamma}{gamma}F1:pFN fibrin). In contrast, fibrin made from 1:1 mixture of {gamma}{gamma}F1 and pFN formed a sporadic distribution of "pFN droplets" (termed {gamma}{gamma}F1 +pFN fibrin). The {gamma}{gamma}F1:pFN fibrin enhanced the adhesion of primary human umbilical vein endothelium cells (HUVECs) relative to the {gamma}{gamma}F1+FN fibrin. Three dimensional (3D) culturing showed that the {gamma}{gamma}F1:pFN complex fibrin matrix enhanced the proliferation of both HUVECs and primary human fibroblasts. HUVECs in the 3D {gamma}{gamma}F1:pFN fibrin exhibited a starkly enhanced vascular morphogenesis while an apoptotic growth profile was observed in the {gamma}{gamma}F1 +pFN fibrin. Relative to {gamma}{gamma}F1 +pFN fibrin, mouse dermal wounds that were sealed by {gamma}{gamma}F1:pFN fibrin exhibited accelerated and enhanced healing. This study suggests that a 3D pFN nano-array presented on a fibrin matrix can promote wound healing.

bioengineering↗

bioRxiv2017

Fluid administration rate for uncontrolled intraabdominal hemorrhage in pigs

BackgroundWe hypothesized that slow crystalloid resuscitation would improve blood loss and hemoglobin compared to a rapid resuscitation during uncontrolled hemorrhage.\n\nMethodsAnesthetized, splenectomized domestic swine underwent hepatic lobar hemitransection. Lactated Ringers was given at 150 or 20 mL/min IV (rapid vs. slow, respectively, N = 12 per group; limit of 100 mL/kg). Vital sign monitoring and serum testing was done for up to 180 min, followed by necropsy.\n\nResultsSurvival was 7 vs. 8 out of 12 subjects, rapid vs. slow respectively (p>0.05). The slow group had a less blood loss (1.6 vs. 2.7 L, respectively) and a higher final hemoglobin concentration (6.0 vs. 3.4 g/dL).\n\nConclusionsUsing a fixed volume of crystalloid resuscitation in this porcine model of uncontrolled intraabdominal hemorrhage, a slow IV infusion rate produced less blood loss and a higher hemoglobin level compared to rapid infusion.

physiology↗