scholarly journals Instant tough bioadhesive with triggerable benign detachment

2020 ◽  
Vol 117 (27) ◽  
pp. 15497-15503 ◽  
Author(s):  
Xiaoyu Chen ◽  
Hyunwoo Yuk ◽  
Jingjing Wu ◽  
Christoph S. Nabzdyk ◽  
Xuanhe Zhao
Keyword(s):  
Wound Closure ◽  
Soft Tissues ◽  
Ex Vivo ◽  
Adhesion Formation ◽  
Interfacial Water ◽  
Mechanical Compliance ◽  
Tissue Surface ◽  
Potential Applications ◽  
Cross Links

Bioadhesives such as tissue adhesives, hemostatic agents, and tissue sealants have potential advantages over sutures and staples for wound closure, hemostasis, and integration of implantable devices onto wet tissues. However, existing bioadhesives display several limitations including slow adhesion formation, weak bonding, low biocompatibility, poor mechanical match with tissues, and/or lack of triggerable benign detachment. Here, we report a bioadhesive that can form instant tough adhesion on various wet dynamic tissues and can be benignly detached from the adhered tissues on demand with a biocompatible triggering solution. The adhesion of the bioadhesive relies on the removal of interfacial water from the tissue surface, followed by physical and covalent cross-linking with the tissue surface. The triggerable detachment of the bioadhesive results from the cleavage of bioadhesive’s cross-links with the tissue surface by the triggering solution. After it is adhered to wet tissues, the bioadhesive becomes a tough hydrogel with mechanical compliance and stretchability comparable with those of soft tissues. We validate in vivo biocompatibility of the bioadhesive and the triggering solution in a rat model and demonstrate potential applications of the bioadhesive with triggerable benign detachment in ex vivo porcine models.

scholarly journals Microfluidics in male reproduction: is ex vivo culture of primate testis tissue a future strategy for ART or toxicology research?

2020 ◽  
Vol 26 (3) ◽  
pp. 179-192 ◽  
Author(s):  
Swati Sharma ◽  
Bastien Venzac ◽  
Thomas Burgers ◽  
Séverine Le Gac ◽  
Stefan Schlatt
Keyword(s):  
Male Infertility ◽  
Functional Organization ◽  
Ex Vivo ◽  
Significant Rise ◽  
Male Reproduction ◽  
Potential Applications ◽  
On Chip ◽  
Bio Engineering

Abstract The significant rise in male infertility disorders over the years has led to extensive research efforts to recapitulate the process of male gametogenesis in vitro and to identify essential mechanisms involved in spermatogenesis, notably for clinical applications. A promising technology to bridge this research gap is organ-on-chip (OoC) technology, which has gradually transformed the research landscape in ART and offers new opportunities to develop advanced in vitro culture systems. With exquisite control on a cell or tissue microenvironment, customized organ-specific structures can be fabricated in in vitro OoC platforms, which can also simulate the effect of in vivo vascularization. Dynamic cultures using microfluidic devices enable us to create stimulatory effect and non-stimulatory culture conditions. Noteworthy is that recent studies demonstrated the potential of continuous perfusion in OoC systems using ex vivo mouse testis tissues. Here we review the existing literature and potential applications of such OoC systems for male reproduction in combination with novel bio-engineering and analytical tools. We first introduce OoC technology and highlight the opportunities offered in reproductive biology in general. In the subsequent section, we discuss the complex structural and functional organization of the testis and the role of the vasculature-associated testicular niche and fluid dynamics in modulating testis function. Next, we review significant technological breakthroughs in achieving in vitro spermatogenesis in various species and discuss the evidence from microfluidics-based testes culture studies in mouse. Lastly, we discuss a roadmap for the potential applications of the proposed testis-on-chip culture system in the field of primate male infertility, ART and reproductive toxicology.

scholarly journals The chemistry of the collagen cross-links. The absence of reduction of dehydrolysinonorleucine and dehydrohydroxylysinonorleucine in vivo

1971 ◽  
Vol 121 (2) ◽  
pp. 257-259 ◽  
Author(s):  
A. J. Bailey ◽  
Catherine M. Peach
Keyword(s):  
Soft Tissues ◽  
Cross Link ◽  
Collagen Fibres ◽  
Cross Links

Two aldimine bonds have been shown to be present as stabilizing cross-links in intact collagen fibres from soft tissues: dehydrohydroxylysinonorleucine as a major component and dehydrolysinonorleucine being present in trace quantities. In the highly insoluble collagens less dehydrohydroxylysinonorleucine is present but the proportion of dehydrolysinonorleucine increases. In elastin the latter aldimine is reduced in vivo to give a more stable cross-link but no comparable reduction could be detected with either of the aldimines present in collagen.

scholarly journals Mechanical Response Changes in Porcine Tricuspid Valve Anterior Leaflet Under Osmotic-Induced Swelling

2019 ◽  
Vol 6 (3) ◽  
pp. 70 ◽  
Author(s):  
Samuel D. Salinas ◽  
Margaret M. Clark ◽  
Rouzbeh Amini
Keyword(s):  
Tricuspid Valve ◽  
Soft Tissues ◽  
Mechanical Response ◽  
Ex Vivo ◽  
Control Group ◽  
Anterior Leaflet ◽  
Buffer Solution ◽  
Tissue Samples ◽  
The Impact

Since many soft tissues function in an isotonic in-vivo environment, it is expected that physiological osmolarity will be maintained when conducting experiments on these tissues ex-vivo. In this study, we aimed to examine how not adhering to such a practice may alter the mechanical response of the tricuspid valve (TV) anterior leaflet. Tissue specimens were immersed in deionized (DI) water prior to quantification of the stress–strain responses using an in-plane biaxial mechanical testing device. Following a two-hour immersion in DI water, the tissue thickness increased an average of 107.3% in the DI water group compared to only 6.8% in the control group, in which the tissue samples were submerged in an isotonic phosphate buffered saline solution for the same period of time. Tissue strains evaluated at 85 kPa revealed a significant reduction in the radial direction, from 34.8% to 20%, following immersion in DI water. However, no significant change was observed in the control group. Our study demonstrated the impact of a hypo-osmotic environment on the mechanical response of TV anterior leaflet. The imbalance in ions leads to water absorption in the valvular tissue that can alter its mechanical response. As such, in ex-vivo experiments for which the native mechanical response of the valves is important, using an isotonic buffer solution is essential.

Curcumin-Loaded Self-Microemulsifying Gel for Enhancing Wound Closure

2021 ◽  
pp. 1-9
Author(s):  
Jiun Wen Guo ◽  
Chi-Ming Pu ◽  
Chih-Yi Liu ◽  
Shih-Lun Lo ◽  
Yu-Hsiu Yen
Keyword(s):  
Wound Healing ◽  
Therapeutic Effect ◽  
Delivery System ◽  
Wound Closure ◽  
Ex Vivo ◽  
Aqueous Solubility ◽  
Punch Biopsy ◽  
Full Thickness ◽  
Sampling System

<b><i>Introduction:</i></b> Wound healing is a process in which damaged cutaneous tissues are repaired and is a dynamic physiological interaction involving several types of cells, tissues, and proteins. Compared with typical treatments, specifically in terms of multifunctional properties, bioactive drug-loaded wound dressing in a controlled and sustained delivery system is an advanced tool that significantly improves wound healing. Curcumin substantially enhances wound healing and prevents oxidative damage. However, the effects of this compound on improving wound healing are limited by its aqueous solubility, poor tissue absorption, and rapid metabolism. Hence, the current study aimed to investigate the therapeutic effect of curcumin-loaded self-microemulsifying gel on wound healing. <b><i>Methods:</i></b> Ex vivo permeation studies of the skin of BALB/c mice were performed using a diffusion cell sampling system. The in vivo therapeutic effect was investigated with a full-thickness wound model. Two 6-mm full-thickness circular wounds were created on the back of the mice via punch biopsy. Then, they received different topical gels for 12 days to enhance wound closure. <b><i>Results:</i></b> The curcumin-loaded self-microemulsifying gel had higher skin flux, cumulative amount, and permeability coefficient than the commercial gels. In addition, it enhanced wound healing. <b><i>Conclusions:</i></b> This is the first study that utilized self-microemulsifying gel loaded with curcumin as a delivery system for wound healing. However, the effect of this delivery system on wound healing or skin disease treatment should be further investigated.

scholarly journals A PEG-Based Hydrogel for Effective Wound Care Management

2018 ◽  
Vol 27 (2) ◽  
pp. 275-284 ◽  
Author(s):  
Sen-Lu Chen ◽  
Ru-Huei Fu ◽  
Shih-Fei Liao ◽  
Shih-Ping Liu ◽  
Shinn-Zong Lin ◽  
...  
Keyword(s):  
Wound Closure ◽  
Soft Tissues ◽  
Wound Care ◽  
In Vitro Biocompatibility ◽  
Synthetic Hydrogel ◽  
Strong Adhesion ◽  
In Vivo Effects ◽  
Sealing Materials

It is extremely challenging to achieve strong adhesion in soft tissues while minimizing toxicity, tissue damage, and other side effects caused by wound sealing materials. In this study, flexible synthetic hydrogel sealants were prepared based on polyethylene glycol (PEG) materials. PEG is a synthetic material that is nontoxic and inert and, thus, suitable for use in medical products. We evaluated the in vitro biocompatibility tests of the dressings to assess cytotoxicity and irritation, sensitization, pyrogen toxicity, and systemic toxicity following the International Organization for Standardization 10993 standards and the in vivo effects of the hydrogel samples using Coloskin liquid bandages as control samples for potential in wound closure.

Fluorescence imaging of tryptophan and collagen cross-links to evaluate wound closure ex vivo

2016 ◽  
Author(s):  
Ying Wang ◽  
Antonio Ortega-Martinez ◽  
Bill Farinelli ◽  
R. R. Anderson ◽  
Walfre Franco
Keyword(s):  
Fluorescence Imaging ◽  
Wound Closure ◽  
Ex Vivo ◽  
Cross Links

Formulation buoyancy of nanoencapsulated gliclazide using primary, conjugated and deconjugated bile acids

2019 ◽  
Vol 10 (9) ◽  
pp. 573-583
Author(s):  
Sangeetha Mathavan ◽  
Corina M Ionescu ◽  
Bozica Kovacevic ◽  
Momir Mikov ◽  
Svetlana Golocorbin-Kon ◽  
...  
Keyword(s):  
Bile Acids ◽  
Sodium Alginate ◽  
Ex Vivo ◽  
Permeation Enhancers ◽  
Human Bile ◽  
Potential Applications ◽  
Specific Uptake ◽  
The Stability

Aim: Recent studies suggest potential applications of endogenously produced human bile acids as formulation-excipient and drug tissue permeation enhancers in Type 1 diabetes. We aimed to examine the stability, tissue permeation and ex vivo muscle-cell effects of microencapsulated gliclazide (G) incorporated with a primary (chenodeoxycholic acid [CDCA]), a secondary (ursodeoxycholic acid [UDCA]) or a tertiary (taurocholic acid [TCA]) bile acid. Materials & methods: Four formulations made of sodium alginate, CDCA, UDCA and TCA were examined for buoyancy, tissue-enhancing effects ( in vivo) and local ( ex vivo) viability effects. Results & conclusion: CDCA, UDCA and TCA improved buoyancy and cell viability but not tissue-specific uptake. G-TCA-sodium alginate microcapsules exerted hypoglycemic effects, suggesting significant improvement of G gut-uptake by TCA, possibly via improving buoyancy.

scholarly journals Development of a refined ex vivo model of peritoneal adhesion formation, and a role for Connexin 43 in their development

2021 ◽  
Author(s):  
Jia Wang Chua ◽  
Leigh Madden ◽  
Beng Hui Lim ◽  
Anthony Phillips ◽  
David Laurence Becker
Keyword(s):  
Connexin 43 ◽  
Drug Testing ◽  
Ex Vivo ◽  
Adhesion Formation ◽  
Ex Vivo Model ◽  
Peritoneal Adhesions ◽  
Peritoneal Tissue ◽  
Junction Protein ◽  
The Impact

Abstract Despite many advances across the surgical sciences, post-surgical peritoneal adhesions still pose a considerable risk in modern-day procedures. We have developed a novel mouse peritoneal strip ex vivo adhesion model which may serve to bridge the gap between single cell culture systems and in vivo animal drug testing for the assessment of potential anti-adhesion agents, and study of causality of the process.We investigated the optimal conditions for adhesion formation with mouse peritoneal tissue strips by modifying an existing ex vivo rat model of peritoneal adhesions. We assessed the impact of the following conditions on the formation of adhesions: contact pressure, abrasions, and the presence of clotted blood.Macroscopic adhesions were detected in all mouse peritoneal strips exposed to specific conditions, namely abrasions and clotted blood, where peritoneal surfaces were kept in contact with pressure using cotton gauze in a tissue cassette. Adhesions were confirmed microscopically. Interestingly, Connexin 43, a gap junction protein, was found to be upregulated at sites of adhesions. Key features of this model were the use of padding the abraded tissue with gauze and the use of a standardised volume of clotted blood. Using this model, peritoneal strips cultured with clotted blood between abraded surfaces were found to reproducibly develop adhesion bands at 72 hours.

scholarly journals Tregitope Peptides: The Active Pharmaceutical Ingredient of IVIG?

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Anne S. De Groot ◽  
Leslie Cousens ◽  
Federico Mingozzi ◽  
William Martin
Keyword(s):  
T Cells ◽  
Ex Vivo ◽  
Chronic Inflammatory Demyelinating Polyneuropathy ◽  
Active Pharmaceutical Ingredient ◽  
Multifocal Motor Neuropathy ◽  
Motor Neuropathy ◽  
T Cell Epitopes ◽  
Pharmaceutical Ingredients ◽  
Potential Applications

Five years ago, we reported the identification and characterization of several regulatory T-cell epitopes (now called Tregitopes) that were discovered in the heavy and light chains of IgG (De Groot et al. Blood, 2008). When added ex vivo to human PBMCs, these Tregitopes activated regulatory T cells (Tregs), increased expression of the transcription factor FoxP3, and induced IL-10 expression in CD4+T cells. We have now shown that coadministration of the Tregitopes in vivo, in a number of different murine models of autoimmune disease, can suppress immune responses to antigen in an antigen-specific manner, and that this response is mediated by Tregs. In addition we have shown that, although these are generally promiscuous epitopes, the activity of individual Tregitope peptides is restricted by HLA. In this brief report, we provide an overview of the effects of Tregitopes in vivo, discuss potential applications, and suggest that Tregitopes may represent one of the “active pharmaceutical ingredients” of IVIg. Tregitope applications may include any of the autoimmune diseases that are currently treated almost exclusively with intravenous immunoglobulin G (IVIG), such as Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) and Multifocal Motor Neuropathy (MMN), as well as gene therapy and allergy where Tregitopes may provide a means of inducing antigen-specific tolerance.

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