Characterization of Macrophage and Cytokine Interactions with Biomaterials Used in Negative-Pressure Wound Therapy

Macrophages are innate immune cells that help wounds heal. Here, we study the potential immunomodulatory effects of negative-pressure wound therapy (NPWT) materials on the macrophage inflammatory response. We compared the effects of two materials, Granufoam™ (GF) and Veraflo Cleanse™ (VC), on macrophage function in vitro. We find that both materials cause reduced expression of inflammatory genes, such as TNF and IL1B, in human macrophages stimulated with bacterial lipopolysaccharide (LPS) and interferon-gamma (IFNγ). Relative to adherent glass control surfaces, VC discourages macrophage adhesion and spreading, and may potentially sequester LPS/IFNγ and cytokines that the cells produce. GF, on the other hand, was less suppressive of inflammation, supported macrophage adhesion and spreading better than VC, and sequestered lesser quantities of LPS/IFNγ in comparison to VC. The control dressing material cotton gauze (CT) was also immunosuppressive, capable of TNF-α retention and LPS/IFNγ sequestration. Our findings suggest that NPWT material interactions with cells, as well as soluble factors including cytokines and LPS, can modulate the immune response, independent of vacuum application. We have also established methodological strategies for studying NPWT materials and reveal the potential utility of cell-based in vitro studies for elucidating biological effects of NPWT materials.

Application of Epigallocatechin-3-gallate (EGCG) Modified 1-Ethyl-3-(3-dimethylaminopropylcarbodiimide hydrochloride/N-hydroxy-succinimide (EDC/NHS) Cross-Linked Collagen Membrane to Promote Macrophage Adhesion

The chemically cross-linking 1-ethyl-3-(3-dimethylaminopropylcarbodiimide hydrochloride/N-hydroxy-succinimide (EDC/NHS) collagen membrane endows such natural polymers with promising mechanical properties. Nevertheless, it is inadequate to advance the modulation of foreign body response (FBR) after implantation or guidance of tissue regeneration. In previous research, macrophages have a strong regulatory effect on regeneration, and such enhanced membranes underwent the modification with Epigallocatechin-3-gallate (EGCG) could adjust the recruitment and phenotypes of macrophages. Accordingly, we develop EGCG-EDC/NHS membranes, prepared with physical immersion, while focusing on the surface morphology through SEM, the biological activity of collagen was determined by FTIR, the activity and adhesion of cell culture in vitro, angiogenesis and monocyte/macrophage recruitment after subcutaneous implantation in vivo, are characterized. It could be concluded that it is hopeful EGCG-EDC/NHS collagen membrane can be used in implant dentistry for it not only retains the advantages of the collagen membrane itself, but also improves cell viability, adhesion, vascularization, and immunoregulation tendency.

ZEB1 controls the expression of ICAM1, promoting monocyte-macrophage adhesion and hence the formation of atherosclerotic lesions

Zinc finger Ebox binding homeobox 1 (ZEB1) regulates the expression of target genes to protect against atherosclerosis. Endothelial dysfunction, monocyte-endothelial cell interactions, and macrophage lipid accumulation are all regulated by ZEB1. A recent study demonstrated that ZEB1 regulates intercellular adhesion molecule 1 (ICAM1) expression, increasing monocyte-macrophage adhesion and the development of atherosclerotic lesions.It seems to be complicated between ZEB1 and atherosclerosis. The diverse effects of ZEB1 might be attributed to several influences. ZEB1 can go from activating to repressing transcription by reacting to numerous inputs. Additionally, ZEB1 controls the expression of multiple target genes and influences many cell types implicated in atherosclerosis development, including endothelial cells, VSMCs, macrophages, and T cells. There are both transcriptional and posttranslational modifications to which ZEB1 responds, demonstrating that the regulation of ZEB1 is complicated. Despite this, accumulating evidence indicates that ZEB1 is an anti-atherosclerotic component. It's critical to figure out whether ZEB1 can help with RCT.Light will be shed on the involvement of ZEB1 in atherogenesis, making ZEB1 a favorable target for atherosclerosis treatment.

Substitution of the SERCA2 Cys674 reactive thiol accelerates atherosclerosis by inducing endo-plasmic reticulum stress and inflammation

BACKGROUND AND PURPOSE The cysteine674 (C674) thiol of Sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2 (SERCA2) is easily and irreversibly oxidized under atherosclerotic conditions. However, contribution of the C674 thiol redox status in the development of atherosclerosis remains unclear. Our goal was to elucidate the possible mechanism involved. EXPERIMENTAL APPROACH Heterozygous SERCA2 C674S knock-in (SKI) mice in which half of the C674 was substituted by serine674 were used to mimic removal of the reactive C674 thiol which occurs under patholog-ical conditions. The whole aorta and aortic root were isolated for histological analysis. Bone marrow derived macrophages (BMDMs) and a cardiac endothelial cell line were used for intra-cellular Ca2+, macrophage adhesion and protein expression analysis. KEY RESULTS SKI mice developed more severe atherosclerotic plaque and macrophage accumulation. Cell cul-ture studies suggest the partial substitution of SERCA2 C674 increased intracellular calcium lev-els and ER stress in both BMDMs and ECs. The release of pro-inflammatory factors and macro-phage adhesion increased in SKI BMDMs. In normal ECs, the overexpression of C674S mutant induced endothelial inflammation and promoted macrophage recruitment. Additionally, 4-phenyl butyric acid (4-PBA), an ER stress inhibitor, prevented the increased atherosclerosis observed in SKI mice, and alleviated ER stress and inflammatory responses in BMDMs and ECs exposed to 4-PBA. CONCLUSIONS AND IMPLICATIONS The substitution of SERCA2 C674 thiol accelerates the development of atherosclerosis by in-ducing ER stress and inflammation. Our findings highlight the importance of SERCA2 C674 redox status in the context of atherosclerosis, and open up a novel therapeutic strategy to combat atherosclerosis.

Application of EGCG modified EDC/NHS cross-linked extracellular matrix to promote macrophage adhesion

Though chemically cross-linked by EDC/NHS endows collagen membrane with promising mechanical properties, it is not conducive to modulation of foreign body reaction (FBR) after implantation or guidance of osteogenesis. In our previous research, we have found that macrophages have a strong regulatory effect on tissue and bone regeneration during FBR, and EGCG modified membranes could adjust the recruitment and phenotypes of macrophages. Accordingly, we develop the EGCG-EDC/NHS membranes, prepared with physically immersion, while the surface morphology of the membrane was observed by SEM, the biological activity of collagen was determined by FTIR, the activity and adhesion of cell culture in vitro, angiogenesis and monocyte/macrophage recruitment after subcutaneous implantation, etc. are characterized. It could be concluded that EGCG-EDC/NHS collagen membrane is hopeful to be used in implant dentistry for it not only retains the advantages of the collagen membrane itself, but also improves cell viability, adhesion and vascularization tendency. However, the mechanism that lies in the regenerative advantages of such membrane needs further exploration, but it is certain that the differences in surface morphology can have a significant impact on the reaction between the host and the implant, not to mention macrophage in bone regeneration.

Conjugating heparin, Arg–Glu–Asp–Val peptide, and anti-CD34 to the silanic Mg–Zn–Y–Nd alloy for better endothelialization

Magnesium alloy is generally accepted as a potential cardiovascular stent material due to its good mechanical properties, biocompatibility, and biodegradability, and has become one of the research hotspots in this field. However, too fast degradation rate and delayed surface endothelialization have been the bottleneck of further application of magnesium alloy stent. In this study, we selected Mg–Zn–Y–Nd, a kind of biodegradable magnesium alloy for cardiovascular stent, and passivated its surface by alkali heat treatment and silane treatment to improve the corrosion resistance, subsequently conjugated Arg–Glu–Asp–Val (REDV) peptide and anti-CD34 to promote endothelial cells adhesion and capture endothelial progenitor cells respectively, further improving surface endothelialization. In addition, the heparin was also immobilized to the Mg–Zn–Y–Nd surface for the consideration of anti-coagulation and anti-inflammation. Systematic material characterization and biological evaluation show that we have successfully developed this composite surface on Mg–Zn–Y–Nd alloy, and achieved multiple functions such as corrosion resistance, promoting endothelialization, and inhibiting platelet/macrophage adhesion.

4R-Cembranoid Treatment Alters Gene Expression of RAW264.7 Macrophages in Basal and Inflammatory Conditions

Inflammation is considered an important target for stroke therapy because it induces secondary brain damage after the initial ischemic insult. Peripheral monocytes migrate to the brain parenchyma after a central insult. They then differentiate to macrophages in a positive feedback fashion contributing to damage instead of ischemic resolution and inflammation control. A cyclic diterpenoid, (1S,2E,4R,6R,7E,11E)-cembra-2,7,11-triene-4,6-diol (4R), decreases neurodegeneration after ischemia with central anti-inflammatory activity. This study aims to determine whether the central anti-inflammatory effect of 4R is effective against peripheral inflammation triggered by brain ischemia. To investigate the anti-inflammatory effect of 4R, we treated macrophages with lipopolysaccharide (LPS) as an inflammatory model, followed by treatment with 4R. Microarray transcriptome analysis of over 30,000 genes identified the differential expression of 393 genes. Genes related to inflammation, cell adhesion, and transcription were validated with qPCR, and reduced expression was determined. Quantification of NF-kB phosphorylation served as a marker for the modulation of inflammation through gene transcription. Our results show that 4R was associated with a reduction in NFKB1 and ITGB5 gene expression, increased phosphorylation of NF-kB, and a decrease in macrophage adhesion in a blood-brain barrier model. These results indicate that 4R can partially modulate the peripheral immune response, making 4R a potential drug against post-ischemic inflammation.