• Title/Summary/Keyword: Biomedical technology

Search Result 2,697, Processing Time 0.034 seconds

Decellularized Matrices for the Treatment of Tissue Defects: from Matrix Origin to Immunological Mechanisms

  • Xinyue Wang;Jiqiang Guo;Qing Yu;Luyao Zhao;Xiang Gao;Li Wang;Meiling Wen;Junrong Yan;Meiwen An;Yang Liu
    • Biomolecules & Therapeutics
    • /
    • v.32 no.5
    • /
    • pp.509-522
    • /
    • 2024
  • Decellularized matrix transplantation has emerged as a promising therapeutic approach for repairing tissue defects, with numerous studies assessing its safety and efficacy in both animal models and clinical settings. The host immune response elicited by decellularized matrix grafts of natural biological origin plays a crucial role in determining the success of tissue repair, influenced by matrix heterogeneity and the inflammatory microenvironment of the wound. However, the specific immunologic mechanisms underlying the interaction between decellularized matrix grafts and the host immune system remain elusive. This article reviews the sources of decellularized matrices, available decellularization techniques, and residual immunogenic components. It focuses on the host immune response following decellularized matrix transplantation, with emphasis on the key mechanisms of Toll-like receptor, T-cell receptor, and TGF-β/SMAD signaling in the stages of post-transplantation immunorecognition, immunomodulation, and tissue repair, respectively. Furthermore, it highlights the innovative roles of TLR10 and miR-29a-3p in improving transplantation outcomes. An in-depth understanding of the molecular mechanisms underlying the host immune response after decellularized matrix transplantation provides new directions for the repair of tissue defects.

A Pattern Recognition Receptor, SIGN-R1, Mediates ROS Generation against Polysaccharide Dextran, Resulting in Increase of Peroxiredoxin-1 and Its Interaction to SIGN-R1

  • Choi, Heong-Jwa;Choi, Woo-Sung;Park, Jin-Yeon;Kang, Kyeong-Hyeon;Prabagar, Miglena G.;Shin, Chan-Young;Kang, Young-Sun
    • Biomolecules & Therapeutics
    • /
    • v.18 no.3
    • /
    • pp.271-279
    • /
    • 2010
  • Streptococcus pneumoniae is the major pathogen that frequently causes serious infections in children, the elderly and immunocompromised patients. S. pneumoniae is known to produce reactive oxygen species (ROS) and S. pneumoniae-produced ROS is considered to play a role in pneumococci pathogenesis. SIGN-R1 is the principal receptor of capsular polysaccharides (CPSs) of S. pneumoniae. However, there is a considerable lack of knowledge about the protective role of SIGN-R1 against S. pneumoniae-produced ROS in SIGN-$R1^+$ macrophages. While investigating the protective role of SIGN-R1 against ROS, we found that SIGN-R1 intimately bound to peroxiredoxin-1 (Prx-1), one of small antioxidant proteins in vitro and in vivo. This interaction was increased with ROS generation which was produced by stimulating SIGN-R1 with dextran, a polysaccharide ligand of SIGN-R1. Also, SIGN-R1 crosslinking with 22D1 anti-SIGN-R1 antibody increased Prx-1 in vitro or in vivo. These results suggested that SIGN-R1 stimulation with CPSs of S. pneumoniae increase the expression level of Prx-1 through ROS and its subsequent interaction to SIGN-R1, providing an important antioxidant role for the host protection against S. pneumoniae.

Effect of Probiotics Lactobacillus and Bifidobacterium on Gut-Derived Lipopolysaccharides and Inflammatory Cytokines: An In Vitro Study Using a Human Colonic Microbiota Model

  • Rodes, Laetitia;Khan, Afshan;Paul, Arghya;Coussa-Charley, Michael;Marinescu, Daniel;Tomaro-Duchesneau, Catherine;Shao, Wei;Kahouli, Imen;Prakash, Satya
    • Journal of Microbiology and Biotechnology
    • /
    • v.23 no.4
    • /
    • pp.518-526
    • /
    • 2013
  • Gut-derived lipopolysaccharides (LPS) are critical to the development and progression of chronic low-grade inflammation and metabolic diseases. In this study, the effects of probiotics Lactobacillus and Bifidobacterium on gut-derived lipopolysaccharide and inflammatory cytokine concentrations were evaluated using a human colonic microbiota model. Lactobacillus reuteri, L. rhamnosus, L. plantarum, Bifidobacterium animalis, B. bifidum, B. longum, and B. longum subsp. infantis were identified from the literature for their anti-inflammatory potential. Each bacterial culture was administered daily to a human colonic microbiota model during 14 days. Colonic lipopolysaccharides, and Gram-positive and negative bacteria were quantified. RAW 264.7 macrophage cells were stimulated with supernatant from the human colonic microbiota model. Concentrations of TNF-${\alpha}$, IL-$1{\beta}$, and IL-4 cytokines were measured. Lipopolysaccharide concentrations were significantly reduced with the administration of B. bifidum ($-46.45{\pm}5.65%$), L. rhamnosus ($-30.40{\pm}5.08%$), B. longum ($-42.50{\pm}1.28%$), and B. longum subsp. infantis ($-68.85{\pm}5.32%$) (p < 0.05). Cell counts of Gram-negative and positive bacteria were distinctly affected by the probiotic administered. There was a probiotic strain-specific effect on immunomodulatory responses of RAW 264.7 macrophage cells. B. longum subsp. infantis demonstrated higher capacities to reduce TNF-${\alpha}$ concentrations ($-69.41{\pm}2.78%$; p < 0.05) and to increase IL-4 concentrations ($+16.50{\pm}0.59%$; p < 0.05). Colonic lipopolysaccharides were significantly correlated with TNF-${\alpha}$ and IL-$1{\beta}$ concentrations (p < 0.05). These findings suggest that specific probiotic bacteria, such as B. longum subsp. infantis, might decrease colonic lipopolysaccharide concentrations, which might reduce the proinflammatory tone. This study has noteworthy applications in the field of biotherapeutics for the prevention and/or treatment of inflammatory and metabolic diseases.

Three-Dimensional Porous Collagen/Chitosan Complex Sponge for Tissue Engineering

  • Kim, Sung Eun;Cho, Yong Woo;Kang, Eun Jung;Kwon, Ick Chan;Lee, Eunhee Bae;Kim, Jung Hyun;Chung, Hesson;Jeong, Seo Young
    • Fibers and Polymers
    • /
    • v.2 no.2
    • /
    • pp.64-70
    • /
    • 2001
  • A three-dimensional, porous collagen/chitosan complex sponge was prepared to closely simulate basic extracellular matrix (ECM) constitutes, collagen and glycosaminoglycan. The complex sponge was prepared by a lyophilization method and had the regular network with highly porous structure, suitable for cell adhesion and growth. The pores were well interconnected, and their distribution was fairly homogeneous. The complex sponge was crosslinked using 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) to increase its boilogical stability and enhance its mechanical properties. The crosslinking medium has a great effect on the inner structure of the sponge. The homogeneous, porous structure of the sponge was remarkably collapsed in an aqueous crosslinking medium. However, the morphology of the sponge remained almost intact in a water/ethanol mixture crosslinking milieu. Mechanical properties of the collagen/chitosan sponge were significantly enhanced by EDC-mediated crosslinking. The potential of the sponge as a scaffold for tissue engineering was investigated using a Chinese hamster ovary cell (CHO-K1) line.

  • PDF

Animal lectins: potential receptors for ginseng polysaccharides

  • Loh, So Hee;Park, Jin-Yeon;Cho, Eun Hee;Nah, Seung-Yeol;Kang, Young-Sun
    • Journal of Ginseng Research
    • /
    • v.41 no.1
    • /
    • pp.1-9
    • /
    • 2017
  • Panax ginseng Meyer, belonging to the genus Panax of the family Araliaceae, is known for its human immune system-related effects, such as immune-boosting effects. Ginseng polysaccharides (GPs) are the responsible ingredient of ginseng in immunomodulation, and are classified as acidic and neutral GPs. Although GPs participate in various immune reactions including the stimulation of immune cells and production of cytokines, the precise function of GPs together with its potential receptor(s) and their signal transduction pathways have remained largely unknown. Animal lectins are carbohydrate-binding proteins that are highly specific for sugar moieties. Among many different biological functions in vivo, animal lectins especially play important roles in the immune system by recognizing carbohydrates that are found exclusively on pathogens or that are inaccessible on host cells. This review summarizes the immunological activities of GPs and the diverse roles of animal lectins in the immune system, suggesting the possibility of animal lectins as the potential receptor candidates of GPs and giving insights into the development of GPs as therapeutic biomaterials for many immunological diseases.