scholarly journals Using nonthermal plasma treatment to improve quality and durability of hydrophilic coatings on hydrophobic polymer surfaces

2019 ◽  
Author(s):  
Greg D. Learn ◽  
Emerson J. Lai ◽  
Horst A. von Recum
Keyword(s):  
Plasma Treatment ◽  
Biological Response ◽  
Covalent Bond ◽  
Nonthermal Plasma ◽  
Consumer Products ◽  
Improve Quality ◽  
Polymeric Substrates ◽  
Substrate Surfaces ◽  
Hydrophilic Coatings

AbstractLow surface energy substrates, which include many polymers in medicine/industry, present challenges toward achieving uniform, adherent, durable coatings, thus limiting intended coating function. Examples include hydrophobic polymers such as polypropylene, polyethylene, polytetrafluoroethylene, and polydimethylsiloxane. These inert materials are used in various biomedical implants due to favorable bulk properties despite perhaps unfavorable surface properties. The capability to coat such materials holds great value as the surface heavily influences biological response and implant function in vivo. Likewise, paint/ink coatings are often necessary on these same plastics, as their final appearance can be critical for automotive, packaging, and consumer products. Substrate exposure to nonthermal plasma was explored here as a means to improve quality of coatings, specifically cyclodextrin-based polyurethanes previously explored for biomedical applications such as controlled drug delivery and anti-biofouling, upon otherwise incompatible polypropylene substrates. Plasma treatment was found to increase wettability and oxygen content on substrate surfaces. These plasma-induced surface alterations were associated with enhanced coating uniformity, and improved coating/substrate adherence – determined to derive partly from interfacial covalent bond formation. Findings demonstrate the utility of plasma-based surface activation as a strategy to improve coating quality on polymeric substrates, and reveal insights regarding mechanisms by which plasma improves polymer coating adherence.

scholarly journals Ultra-strong bio-glue from genetically engineered polypeptides

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chao Ma ◽  
Jing Sun ◽  
Bo Li ◽  
Yang Feng ◽  
Yao Sun ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Covalent Bond ◽  
Genetically Engineered ◽  
Supramolecular Interactions ◽  
Molar Ratio ◽  
High Adhesion ◽  
Strong Adhesion ◽  
Order Of Magnitude

AbstractThe development of biomedical glues is an important, yet challenging task as seemingly mutually exclusive properties need to be combined in one material, i.e. strong adhesion and adaption to remodeling processes in healing tissue. Here, we report a biocompatible and biodegradable protein-based adhesive with high adhesion strengths. The maximum strength reaches 16.5 ± 2.2 MPa on hard substrates, which is comparable to that of commercial cyanoacrylate superglue and higher than other protein-based adhesives by at least one order of magnitude. Moreover, the strong adhesion on soft tissues qualifies the adhesive as biomedical glue outperforming some commercial products. Robust mechanical properties are realized without covalent bond formation during the adhesion process. A complex consisting of cationic supercharged polypeptides and anionic aromatic surfactants with lysine to surfactant molar ratio of 1:0.9 is driven by multiple supramolecular interactions enabling such strong adhesion. We demonstrate the glue’s robust performance in vitro and in vivo for cosmetic and hemostasis applications and accelerated wound healing by comparison to surgical wound closures.

scholarly journals Real-time observation of tetrapyrrole binding to an engineered bacterial phytochrome

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yusaku Hontani ◽  
Mikhail Baloban ◽  
Francisco Velazquez Escobar ◽  
Swetta A. Jansen ◽  
Daria M. Shcherbakova ◽  
...  
Keyword(s):  
Real Time ◽  
Rational Design ◽  
Near Infrared ◽  
Fluorescent Proteins ◽  
Covalent Bond ◽  
Binding Pocket ◽  
Tissue Imaging ◽  
Covalent Attachment ◽  
Time Resolved

AbstractNear-infrared fluorescent proteins (NIR FPs) engineered from bacterial phytochromes are widely used for structural and functional deep-tissue imaging in vivo. To fluoresce, NIR FPs covalently bind a chromophore, such as biliverdin IXa tetrapyrrole. The efficiency of biliverdin binding directly affects the fluorescence properties, rendering understanding of its molecular mechanism of major importance. miRFP proteins constitute a family of bright monomeric NIR FPs that comprise a Per-ARNT-Sim (PAS) and cGMP-specific phosphodiesterases - Adenylyl cyclases - FhlA (GAF) domain. Here, we structurally analyze biliverdin binding to miRFPs in real time using time-resolved stimulated Raman spectroscopy and quantum mechanics/molecular mechanics (QM/MM) calculations. Biliverdin undergoes isomerization, localization to its binding pocket, and pyrrolenine nitrogen protonation in <1 min, followed by hydrogen bond rearrangement in ~2 min. The covalent attachment to a cysteine in the GAF domain was detected in 4.3 min and 19 min in miRFP670 and its C20A mutant, respectively. In miRFP670, a second C–S covalent bond formation to a cysteine in the PAS domain occurred in 14 min, providing a rigid tetrapyrrole structure with high brightness. Our findings provide insights for the rational design of NIR FPs and a novel method to assess cofactor binding to light-sensitive proteins.

Cold Plasma Treatment Promotes Full-thickness Healing of Skin Wounds in Murine Models

2021 ◽  
pp. 153473462110021
Author(s):  
Joon M. Jung ◽  
Hae K. Yoon ◽  
Chang J. Jung ◽  
Soo Y. Jo ◽  
Sang G. Hwang ◽  
...  
Keyword(s):  
Wound Healing ◽  
Plasma Treatment ◽  
Cold Plasma ◽  
Smooth Muscle Actin ◽  
Treated Group ◽  
Control Group ◽  
Alpha Smooth Muscle Actin ◽  
Skin Wound Healing

Cold plasma can be beneficial for promoting skin wound healing and has a high potential of being effectively used in treating various wounds. Our aim was to verify the effect of cold plasma in accelerating wound healing and investigate its underlying mechanism in vitro and in vivo. For the in vivo experiments, 2 full-thickness dermal wounds were created in each mouse (n = 30). While one wound was exposed to 2 daily plasma treatments for 3 min, the other wound served as a control. The wounds were evaluated by imaging and histological analyses at 4, 7, and 11 days post the wound infliction process. Immunohistochemical studies were also performed at the same time points. In vitro proliferation and scratch assay using HaCaT keratinocytes and fibroblasts were performed. The expression levels of wound healing–related genes were analyzed by real-time polymerase chain reaction and western blot analysis. On day 7, the wound healing rates were 53.94% and 63.58% for the control group and the plasma-treated group, respectively. On day 11, these rates were 76.05% and 93.44% for the control and plasma-treated groups, respectively, and the difference between them was significant ( P = .039). Histological analysis demonstrated that plasma treatment promotes the formation of epidermal keratin and granular layers. Immunohistochemical studies also revealed that collagen 1, collagen 3, and alpha-smooth muscle actin appeared more abundantly in the plasma-treated group than in the control group. In vitro, the proliferation of keratinocytes was promoted by plasma exposure. Scratch assay showed that fibroblast exposure to plasma increased their migration. The expression levels of collagen 1, collagen 3, and alpha-smooth muscle actin were elevated upon plasma treatment. In conclusion, cold plasma can accelerate skin wound healing and is well tolerated.

scholarly journals The application prospect of metal/metal oxide nanoparticles in the treatment of osteoarthritis

2021 ◽  
Vol 394 (10) ◽  
pp. 1991-2002
Author(s):  
Junchao Luo ◽  
Yin Zhang ◽  
Senbo Zhu ◽  
Yu Tong ◽  
Lichen Ji ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Metal Oxide Nanoparticles ◽  
Biological Response ◽  
Cell Uptake ◽  
Oxide Nanoparticles ◽  
Therapeutic Effects ◽  
Superoxide Anions ◽  
Metal Metal ◽  
Cartilage Wear

AbstractThe current understanding of osteoarthritis is developing from a mechanical disease caused by cartilage wear to a complex biological response involving inflammation, oxidative stress and other aspects. Nanoparticles are widely used in drug delivery due to its good stability in vivo and cell uptake efficiency. In addition to the above advantages, metal/metal oxide NPs, such as cerium oxide and manganese dioxide, can also simulate the activity of antioxidant enzymes and catalyze the degradation of superoxide anions and hydrogen peroxide. Degrading of metal/metal oxide nanoparticles releases metal ions, which may slow down the progression of osteoarthritis by inhibiting inflammation, promoting cartilage repair and inhibiting cartilage ossification. In present review, we focused on recent research works concerning osteoarthritis treating with metal/metal oxide nanoparticles, and introduced some potential nanoparticles that may have therapeutic effects.

scholarly journals Pseudomonas aeruginosa Biofilm Inactivation: Decreased Cell Culturability, Adhesiveness to Surfaces, and Biofilm Thickness Upon High-Pressure Nonthermal Plasma Treatment

2010 ◽  
Vol 38 (12) ◽  
pp. 3398-3403 ◽  
Author(s):  
Anna J. Zelaya ◽  
Gregory Stough ◽  
Navid Rad ◽  
Kurt Vandervoort ◽  
Graciela Brelles-Mariño
Keyword(s):  
Pseudomonas Aeruginosa ◽  
High Pressure ◽  
Plasma Treatment ◽  
Nonthermal Plasma ◽  
Biofilm Thickness

scholarly journals Targeting of p38 Mitogen-Activated Protein Kinases to MEF2 Transcription Factors

1999 ◽  
Vol 19 (6) ◽  
pp. 4028-4038 ◽  
Author(s):  
Shen-Hsi Yang ◽  
Alex Galanis ◽  
Andrew D. Sharrocks
Keyword(s):  
Transcription Factors ◽  
Transcriptional Activation ◽  
Cellular Response ◽  
Map Kinases ◽  
Biological Response ◽  
Extracellular Signals ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

ABSTRACT Mitogen-activated protein (MAP) kinase-mediated signalling to the nucleus is an important event in the conversion of extracellular signals into a cellular response. However, the existence of multiple MAP kinases which phosphorylate similar phosphoacceptor motifs poses a problem in maintaining substrate specificity and hence the correct biological response. Both the extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK) subfamilies of MAP kinases use a second specificity determinant and require docking to their transcription factor substrates to achieve maximal substrate activation. In this study, we demonstrate that among the different MAP kinases, the MADS-box transcription factors MEF2A and MEF2C are preferentially phosphorylated and activated by the p38 subfamily members p38α and p38β2. The efficiency of phosphorylation in vitro and transcriptional activation in vivo of MEF2A and MEF2C by these p38 subtypes requires the presence of a kinase docking domain (D-domain). Furthermore, the D-domain from MEF2A is sufficient to confer p38 responsiveness on different transcription factors, and reciprocal effects are observed upon the introduction of alternative D-domains into MEF2A. These results therefore contribute to our understanding of signalling to MEF2 transcription factors and demonstrate that the requirement for substrate binding by MAP kinases is an important facet of three different subclasses of MAP kinases (ERK, JNK, and p38).

Toxicity of direct nonthermal plasma treatment of living tissue

2009 ◽  
Author(s):  
Danil Dobrynin ◽  
Sameer Kalghatgi ◽  
Gregory Fridman ◽  
Andrew Wu ◽  
Erica Podolsky ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Nonthermal Plasma ◽  
Living Tissue

A brief overview on role of graphene based material in therapeutic management of inflammatory response signalling cascades

2020 ◽  
Vol 21 ◽  
pp. 25-36
Author(s):  
Ruchira Das ◽  
◽  
Priyanka Sow ◽  
Sudatta Dey ◽  
Asmita Samadder ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Water Solubility ◽  
Biomedical Application ◽  
Rapid Development ◽  
Graphene Quantum Dots ◽  
Biological Response ◽  
Vital Role ◽  
Therapeutic Management ◽  
In Vivo Models

Graphene is a novel, sp2 carbon atoms bonded, two-dimensional nano-material. Due to their favorable electronic, thermal, optical, and mechanical property, graphene and its derivatives, like graphene oxide (GO) and graphene quantum dots (GQDs) are used in widespread applications. The outstanding potentials of these compounds in the field of nanoelectronics, composite materials, sensors, energy technology etc helped in the rapid development in their functionalization, modulatory effects on various systems of our body. GQDs has been suggested as a new nanomaterial with improved biocompatibility, biodegradability, water solubility and considerably low cytotoxic effects in in vivo models, and are applicable for altering immune responses based on quantum confinement and edge effect properties. The review particularly elucidates the mechanistic approach by which graphene and/ or its derivatives and/ or their nano-compound aid in therapeutic management against myriads of immunological perspectives. GQDs have unique physiochemical properties with carbon sheets showcases out-standing biological response against immunological interventions by altering the activities of t-cell lymphocytes. On the contrary GO plays a vital role in eliciting inflammatory signaling factors by controlling proinflammation and an anti-inflammatory response. Therefore, this review shall help the readers to have an overview of the biomedical application of graphene and its derivatives to design target specific drugs to regulate the immune response based prognosis andcure.

In vivo effects of human recombinant tumor necrosis factor alone and in combination with other biological response modifiers on human digestive organ cancer xenografts transplanted in nude mice

Biotherapy ◽  
1991 ◽  
Vol 3 (4) ◽  
pp. 337-344 ◽  
Author(s):  
Yoshinori Nio ◽  
Takahiro Shiraishi ◽  
Michihiko Tsubono ◽  
Hideki Morimoto ◽  
Chen-Chiu Tseng ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Nude Mice ◽  
Tumor Necrosis ◽  
Biological Response ◽  
Digestive Organ ◽  
Biological Response Modifiers ◽  
In Vivo Effects ◽  
Recombinant Tumor Necrosis Factor ◽  
Necrosis Factor

scholarly journals Microbial enzymes induce colitis by reactivating triclosan in the mouse gastrointestinal tract

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Jianan Zhang ◽  
Morgan E. Walker ◽  
Katherine Z. Sanidad ◽  
Hongna Zhang ◽  
Yanshan Liang ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Metabolic Activation ◽  
Consumer Products ◽  
Environmental Chemicals ◽  
Intestinal Microbes ◽  
Targeted Inhibition

AbstractEmerging research supports that triclosan (TCS), an antimicrobial agent found in thousands of consumer products, exacerbates colitis and colitis-associated colorectal tumorigenesis in animal models. While the intestinal toxicities of TCS require the presence of gut microbiota, the molecular mechanisms involved have not been defined. Here we show that intestinal commensal microbes mediate metabolic activation of TCS in the colon and drive its gut toxicology. Using a range of in vitro, ex vivo, and in vivo approaches, we identify specific microbial β-glucuronidase (GUS) enzymes involved and pinpoint molecular motifs required to metabolically activate TCS in the gut. Finally, we show that targeted inhibition of bacterial GUS enzymes abolishes the colitis-promoting effects of TCS, supporting an essential role of specific microbial proteins in TCS toxicity. Together, our results define a mechanism by which intestinal microbes contribute to the metabolic activation and gut toxicity of TCS, and highlight the importance of considering the contributions of the gut microbiota in evaluating the toxic potential of environmental chemicals.

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