Methyl Syringate: A Primary Driving Factor in Manuka Honeys Ability to Ameliorate Neutrophil Intracellular ROS Activity and NETosis.

Background: Neutrophils use both the production of reactive oxygen species (ROS) and a specialized process called NETosis to defend the body from material deemed foreign. While these neutrophil behaviors are critical in preventing infection, a dysregulated response can lead to tissue damage and fibrosis at host-biomaterial interfaces. It was hypothesized that applying the flavonoids found in Manuka honey: chrysin, pinocembrin, and pinobanksin, and the phenolic compound methyl syringate to neutrophils exhibiting pro-inflammatory behavior will reduce ROS activity and prevent NETosis in primary human neutrophils.

Neutrophil Activity and Extracellular Matrix Degradation: Drivers of Lung Tissue Destruction in Fatal COVID-19 Cases and Implications for Long COVID.

Pulmonary fibrosis, severe alveolitis, and the inability to restore alveolar epithelial architecture are primary causes of respiratory failure in fatal COVID-19 cases. However, the factors contributing to abnormal fibrosis in critically ill COVID-19 patients remain unclear. This study analyzed the histopathology of lung specimens from eight COVID-19 and six non-COVID-19 postmortems.

Light induced expression of gRNA allows for optogenetic gene editing of T lymphocytes in vivo.

There is currently a lack of tools capable of perturbing genes in both a precise and spatiotemporal fashion. CRISPR's ease of use and flexibility, coupled with light's unparalleled spatiotemporal resolution deliverable from a controllable source, makes optogenetic CRISPR a well-suited solution for precise spatiotemporal gene perturbations. Here we present a new optogenetic CRISPR tool, BLU-VIPR, that diverges from prevailing split-Cas design strategies and instead focuses on optogenetic regulation of gRNA production.

Mitochondria as a therapeutic: a potential new frontier in driving the shift from tissue repair to regeneration.

Fibrosis, or scar tissue development, is associated with numerous pathologies and is often considered a worst-case scenario in terms of wound healing or the implantation of a biomaterial. All that remains is a disorganized, densely packed and poorly vascularized bundle of connective tissue, which was once functional tissue. This creates a significant obstacle to the restoration of tissue function or integration with any biomaterial.

Near-field electrospinning of polydioxanone small diameter vascular graft scaffolds.

The ideal "off the shelf" tissue engineering, small-diameter (SD) vascular graft hinges on designing a scaffold to act as a template that facilitates transmural ingrowth of capillaries to regenerate an endothelized neointimal surface. Towards this goal, we explored two types of near-field electrospun (NFES) polydioxanone (PDO) architectures, as SD vascular graft scaffolds. The first architecture type consisted of a 200 × 200 μm and 500 × 500 μm grid geometry with random fiber infill, while the second architecture consisted of aligned fibers written in a 45°/45° and 20°/70° offset from the long axis written, both on a 4 mm diameter cylindrical mandrel.

Methods for Quantifying Neutrophil Extracellular Traps on Biomaterials.

Neutrophils rapidly accumulate at sites of inflammation, including biomaterial implantation sites, where they can modulate the microenvironment toward repair through a variety of functions, including superoxide generation, granule release, and extrusion of neutrophil extracellular traps (NETs). NETs are becoming increasing implicated as a central player in the host response to a biomaterial, and as such, there is a need for reliable in vitro methods to evaluate the relative degree of NETs and quantify NETs on the surface of biomaterials. Such methods should be relatively high throughput and minimize sampling bias.

Mechanical characterization and neutrophil NETs response of a novel hybrid geometry polydioxanone near-field electrospun scaffold.

Near-field electrospinning (NFES) is a direct fiber writing sub-technique derived from traditional electrospinning (TES) by reducing the air gap distance to the magnitude of millimeters. In this paper, we demonstrate a NFES device designed from a commercial 3D printer to semi-stably write polydioxanone (PDO) microfibers. The print head was then programmed to translate in a stacking grid pattern, which resulted in a scaffold with highly aligned grid fibers that were intercalated with low density, random fibers.

Human neutrophil FcγRIIIb regulates neutrophil extracellular trap release in response to electrospun polydioxanone biomaterials.

During the acute inflammatory response, the release of neutrophil extracellular traps (NETs) is a pro-inflammatory, preconditioning event on a biomaterial surface. Therefore, regulation of NET release through biomaterial design is one strategy to enhance biomaterial-guided in situ tissue regeneration. In this study, IgG adsorption on electrospun polydioxanone biomaterials with differing fiber sizes was explored as a regulator of in vitro human neutrophil NET release.

Patients with COVID-19: in the dark-NETs of neutrophils.

SARS-CoV-2 infection poses a major threat to the lungs and multiple other organs, occasionally causing death. Until effective vaccines are developed to curb the pandemic, it is paramount to define the mechanisms and develop protective therapies to prevent organ dysfunction in patients with COVID-19. Individuals that develop severe manifestations have signs of dysregulated innate and adaptive immune responses.

Electrospun Polydioxanone Loaded With Chloroquine Modulates Template-Induced NET Release and Inflammatory Responses From Human Neutrophils.

The implantation of a biomaterial quickly initiates a tissue repair program initially characterized by a neutrophil influx. During the acute inflammatory response, neutrophils release neutrophil extracellular traps (NETs) and secrete soluble signals to modulate the tissue environment. In this work, we evaluated chloroquine diphosphate, an antimalarial with immunomodulatory and antithrombotic effects, as an electrospun biomaterial additive to regulate neutrophil-mediated inflammation.

Near-Field Electrospinning and Melt Electrowriting of Biomedical Polymers-Progress and Limitations.

Near-field electrospinning (NFES) and melt electrowriting (MEW) are the process of extruding a fiber due to the force exerted by an electric field and collecting the fiber before bending instabilities occur. When paired with precise relative motion between the polymer source and the collector, a fiber can be directly written as dictated by preprogrammed geometry. As a result, this precise fiber control results in another dimension of scaffold tailorability for biomedical applications.

Neutrophil Extracellular Traps: Inflammation and Biomaterial Preconditioning for Tissue Engineering.

Tissue injury initiates a tissue repair program, characterized by acute inflammation and recruitment of immune cells, dominated by neutrophils. Neutrophils prevent infection in the injured tissue through multiple effector functions, including the production of reactive oxygen species, the release of granules, the phagocytosis of invaders, and the extrusion of neutrophil extracellular traps (NETs). However, these canonical protective mechanisms can also have detrimental effects both in the context of infection and in response to sterile injuries.

Manuka Honey Reduces NETosis on an Electrospun Template Within a Therapeutic Window.

Manuka honey, a topical wound treatment used to eradicate bacteria, resolve inflammation, and promote wound healing, is a focus in the tissue engineering community as a tissue template additive. However, its effect on neutrophil extracellular trap formation (NETosis) on a tissue engineering template has yet to be examined. As NETosis has been implicated in chronic inflammation and fibrosis, the reduction in this response within the wound environment is of interest.

37/67-laminin receptor facilitates neural crest cell migration during enteric nervous system development.

Enteric nervous system (ENS) development is governed by interactions between neural crest cells (NCC) and the extracellular matrix (ECM). Hirschsprung disease (HSCR) results from incomplete NCC migration and failure to form an appropriate ENS. Prior studies implicate abnormal ECM in NCC migration failure.

An atorvastatin calcium and poly(L-lactide-co-caprolactone) core-shell nanofiber-covered stent to treat aneurysms and promote reendothelialization.

Aneurysmal subarachnoid hemorrhage is a common complication caused by an intracranial aneurysm that can lead to hemorrhagic stroke, brain damage, and death. Knowing this clinical situation, the purpose of this study was to develop a controlled-release stent covered with a core-shell nanofiber mesh, fabricated by emulsion electrospinning, for the treatment of aneurysms. By encapsulating atorvastatin calcium (AtvCa) in the inner of poly (L-lactide-co-caprolactone) (PLCL) nanofibers, the release period of AtvCa was effectively extended.

Neutrophils in Biomaterial-Guided Tissue Regeneration: Matrix Reprogramming for Angiogenesis.

Biomaterial-guided tissue regeneration uses biomaterials to stimulate and guide the body's endogenous, regenerative processes to drive functional tissue repair and regeneration. To be successful, cell migration into the biomaterials is essential, which requires angiogenesis to maintain cell viability. Neutrophils, the first cells responding to an implanted biomaterial, are now known to play an integral part in angiogenesis in multiple tissues and exhibit considerable potential for driving angiogenesis in the context of tissue regeneration.

Manuka honey modulates the release profile of a dHL-60 neutrophil model under anti-inflammatory stimulation.

Manuka honey, a wound treatment used to eradicate bacteria, resolve inflammation, and promote wound healing, is a current focus in the tissue engineering community as a tissue template additive. However, Manuka honey's effect on neutrophils during the inflammation-resolving phase has yet to be examined. This study investigates the effect of 0.

Characterization of Polydioxanone in Near-Field Electrospinning.

Electrospinning is a popular method for creating random, non-woven fibrous templates for biomedical applications, and a subtype technique termed near-field electrospinning (NFES) was devised by reducing the air gap distance to millimeters. This decreased working distance paired with precise translational motion between the fiber source and collector allows for the direct writing of fibers. We demonstrate a near-field electrospinning device designed from a MakerFarm Prusa i3v three-dimensional (3D) printer to write polydioxanone (PDO) microfibers.

Surface Area to Volume Ratio of Electrospun Polydioxanone Templates Regulates the Adsorption of Soluble Proteins from Human Serum.

Neutrophils, the first cells that interact with surface-adsorbed proteins on biomaterials, have been increasingly recognized as critical maestros in the foreign body response for guided tissue regeneration. Recent research has shown that small diameter (SD) fibers of electrospun tissue regeneration templates, which have a high surface area to volume ratio (SAVR), enhance the release of neutrophil extracellular traps (NETs) compared to large diameter (LD) fibers, resulting in impaired tissue regeneration. In this study, we evaluated the adsorption of eight human serum proteins on the surface of electrospun templates to investigate how protein adsorption may regulate the release of NETs.

The Effect of Manuka Honey on dHL-60 Cytokine, Chemokine, and Matrix-Degrading Enzyme Release under Inflammatory Conditions.

A large body of and evidence indicates that Manuka honey resolves inflammation and promotes healing when applied topically to a wound. In this study, the effect of two different concentrations (0.5% and 3% v/v) of Manuka honey on the release of cytokines, chemokines, and matrix-degrading enzymes from neutrophils was examined using a differentiated HL-60 cell line model in the presence of inflammatory stimuli.

Manuka Honey Modulates the Inflammatory Behavior of a dHL-60 Neutrophil Model under the Cytotoxic Limit.

Recent work has shown that Manuka honey, an increasingly popular wound additive with potent antibacterial properties, also has anti-inflammatory properties. However, little research has been done examining its effect on neutrophils. This study investigates the hypothesis that Manuka honey reduces neutrophil superoxide release and chemotaxis and reduces the activation of the inflammatory nuclear factor-B (NF-B) signaling pathway under honey's cytotoxic limit.

Design and Fabrication of a Biomimetic Vascular Scaffold Promoting in Situ Endothelialization and Tunica Media Regeneration.

Multilayered vascular scaffolds may be considered advantageous in regenerating vascular tissues due to the nature of mimicking the native structure of a blood vessel. However, there are currently limited small-diameter vascular scaffolds integrating the specific features of native tunica intima (anti-thrombus and rapid endothelialization) and tunica media (the alignment and ingrowth of smooth muscle cells (SMCs), structural elements capable of promoting vascular regeneration and function). To address this limitation, we developed a modified electrospinning method capable of fabricating a bilayer vascular scaffold with a 2-mm inner diameter and investigated the performance and regenerative capacity using a rat abdominal aorta, with a 2-month implantation period.

Honey-Based Templates in Wound Healing and Tissue Engineering.

Over the past few decades, there has been a resurgence in the clinical use of honey as a topical wound treatment. A plethora of in vitro and in vivo evidence supports this resurgence, demonstrating that honey debrides wounds, kills bacteria, penetrates biofilm, lowers wound pH, reduces chronic inflammation, and promotes fibroblast infiltration, among other beneficial qualities. Given these results, it is clear that honey has a potential role in the field of tissue engineering and regeneration.

Localized Delivery of Cl-Amidine From Electrospun Polydioxanone Templates to Regulate Acute Neutrophil NETosis: A Preliminary Evaluation of the PAD4 Inhibitor for Tissue Engineering.

Upon interaction, neutrophils can potentially release neutrophil extracellular traps (NETs) on the surface of an implanted electrospun template, which may be a significant preconditioning event for implantable biomaterials of yet unknown consequences. In this study, we investigated the potential of polydioxanone templates as a delivery vehicle for Cl-amidine, an inhibitor of peptidyl arginase deiminase 4 (PAD4), and if drug elution could attenuate PAD4-mediated NETosis in the vicinity of implanted templates. Electrospun polydioxanone templates were fabricated with distinct architectures, small diameter (0.

An overview of the role of neutrophils in innate immunity, inflammation and host-biomaterial integration.

Despite considerable recent progress in defining neutrophil functions and behaviors in tissue repair, much remains to be determined with regards to its overall role in the tissue integration of biomaterials. This article provides an overview of the neutrophil's numerous, important roles in both inflammation and resolution, and subsequently, their role in biomaterial integration. Neutrophils function in three primary capacities: generation of oxidative bursts, release of granules and formation of neutrophil extracellular traps (NETs); these combined functions enable neutrophil involvement in inflammation, macrophage recruitment, M2 macrophage differentiation, resolution of inflammation, angiogenesis, tumor formation and immune system activation.