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1.
Cell Host Microbe ; 2024 Sep 04.
Article in English | MEDLINE | ID: mdl-39243760

ABSTRACT

The role of immunoglobulins produced by IL-10-producing regulatory B cells remains unknown. We found that a particular newborn regulatory B cell population (nBreg) negatively regulates the production of immunoglobulin M (IgM) via IL-10 in an autocrine manner, limiting the intensity of the polyreactive antibody response following innate activation. Based on nBreg scRNA-seq signature, we identify these cells and their repertoire in fetal and neonatal intestinal tissues. By characterizing 205 monoclonal antibodies cloned from intestinal nBreg, we show that newborn germline-encoded antibodies display reactivity against bacteria representing six different phyla of the early microbiota. nBreg-derived antibodies can influence the diversity and the cooperation between members of early microbial communities, at least in part by modulating energy metabolism. These results collectively suggest that nBreg populations help facilitate early-life microbiome establishment and shed light on the paradoxical activities of regulatory B cells in early life.

2.
Nat Commun ; 15(1): 1957, 2024 Mar 04.
Article in English | MEDLINE | ID: mdl-38438348

ABSTRACT

Almost all Glioblastoma (GBM) are either intrinsically resistant to the chemotherapeutical drug temozolomide (TMZ) or acquire therapy-induced mutations that cause chemoresistance and recurrence. The genome maintenance mechanisms responsible for GBM chemoresistance and hypermutation are unknown. We show that the E3 ubiquitin ligase RAD18 (a proximal regulator of TLS) is activated in a Mismatch repair (MMR)-dependent manner in TMZ-treated GBM cells, promoting post-replicative gap-filling and survival. An unbiased CRISPR screen provides an aerial map of RAD18-interacting DNA damage response (DDR) pathways deployed by GBM to tolerate TMZ genotoxicity. Analysis of mutation signatures from TMZ-treated GBM reveals a role for RAD18 in error-free bypass of O6mG (the most toxic TMZ-induced lesion), and error-prone bypass of other TMZ-induced lesions. Our analyses of recurrent GBM patient samples establishes a correlation between low RAD18 expression and hypermutation. Taken together we define molecular underpinnings for the hallmark tumorigenic phenotypes of TMZ-treated GBM.


Subject(s)
Glioblastoma , Humans , Glioblastoma/drug therapy , Glioblastoma/genetics , Translesion DNA Synthesis , DNA Mismatch Repair/genetics , Drug Resistance, Neoplasm/genetics , Temozolomide/pharmacology , DNA-Binding Proteins , Ubiquitin-Protein Ligases/genetics
3.
Res Sq ; 2023 Oct 16.
Article in English | MEDLINE | ID: mdl-37886584

ABSTRACT

Almost all Glioblastoma (GBM) are either intrinsically resistant to the chemotherapeutical drug temozolomide (TMZ) or acquire therapy-induced mutations that cause chemoresistance and recurrence. The genome maintenance mechanisms responsible for GBM chemoresistance and hypermutation are unknown. We show that the E3 ubiquitin ligase RAD18 (a proximal regulator of TLS) is activated in a Mismatch repair (MMR)-dependent manner in TMZ-treated GBM cells, promoting post-replicative gap-filling and survival. An unbiased CRISPR screen provides a new aerial map of RAD18-interacting DNA damage response (DDR) pathways deployed by GBM to tolerate TMZ genotoxicity. Analysis of mutation signatures from TMZ-treated GBM reveals a role for RAD18 in error-free bypass of O6mG (the most toxic TMZ-induced lesion), and error-prone bypass of other TMZ-induced lesions. Our analyses of recurrent GBM patient samples establishes a correlation between low RAD18 expression and hypermutation. Taken together we define novel molecular underpinnings for the hallmark tumorigenic phenotypes of TMZ-treated GBM.

4.
Sci Signal ; 16(809): eadf8299, 2023 10 31.
Article in English | MEDLINE | ID: mdl-37906629

ABSTRACT

Mechanical cues sensed by integrins induce cells to produce proteases to remodel the extracellular matrix. Excessive protease production occurs in many degenerative diseases, including osteoarthritis, in which articular cartilage degradation is associated with the genesis of matrix protein fragments that can activate integrins. We investigated the mechanisms by which integrin signals may promote protease production in response to matrix changes in osteoarthritis. Using a fragment of the matrix protein fibronectin (FN) to activate the α5ß1 integrin in primary human chondrocytes, we found that endocytosis of the integrin and FN fragment complex drove the production of the matrix metalloproteinase MMP-13. Activation of α5ß1 by the FN fragment, but not by intact FN, was accompanied by reactive oxygen species (ROS) production initially at the cell surface, then in early endosomes. These ROS-producing endosomes (called redoxosomes) contained the integrin-FN fragment complex, the ROS-producing enzyme NADPH oxidase 2 (NOX2), and SRC, a redox-regulated kinase that promotes MMP-13 production. In contrast, intact FN was endocytosed and trafficked to recycling endosomes without inducing ROS production. Articular cartilage from patients with osteoarthritis showed increased amounts of SRC and the NOX2 complex component p67phox. Furthermore, we observed enhanced localization of SRC and p67phox at early endosomes, suggesting that redoxosomes could transmit and sustain integrin signaling in response to matrix damage. This signaling mechanism not only amplifies the production of matrix-degrading proteases but also establishes a self-perpetuating cycle that contributes to the ongoing degradation of cartilage matrix in osteoarthritis.


Subject(s)
Cartilage, Articular , Osteoarthritis , Humans , Chondrocytes , Matrix Metalloproteinase 13/genetics , Matrix Metalloproteinase 13/metabolism , Reactive Oxygen Species/metabolism , Integrin alpha5beta1/genetics , Integrin alpha5beta1/metabolism , Integrins/genetics , Integrins/metabolism , Cartilage, Articular/metabolism , Oxidation-Reduction , Endosomes/metabolism
5.
bioRxiv ; 2023 Oct 19.
Article in English | MEDLINE | ID: mdl-37905107

ABSTRACT

Almost all Glioblastoma (GBM) are either intrinsically resistant to the chemotherapeutical drug temozolomide (TMZ) or acquire therapy-induced mutations that cause chemoresistance and recurrence. The genome maintenance mechanisms responsible for GBM chemoresistance and hypermutation are unknown. We show that the E3 ubiquitin ligase RAD18 (a proximal regulator of TLS) is activated in a Mismatch repair (MMR)-dependent manner in TMZ-treated GBM cells, promoting post-replicative gap-filling and survival. An unbiased CRISPR screen provides a new aerial map of RAD18-interacting DNA damage response (DDR) pathways deployed by GBM to tolerate TMZ genotoxicity. Analysis of mutation signatures from TMZ-treated GBM reveals a role for RAD18 in error-free bypass of O6mG (the most toxic TMZ-induced lesion), and error-prone bypass of other TMZ-induced lesions. Our analyses of recurrent GBM patient samples establishes a correlation between low RAD18 expression and hypermutation. Taken together we define novel molecular underpinnings for the hallmark tumorigenic phenotypes of TMZ-treated GBM.

6.
Cancer Med ; 12(2): 2075-2088, 2023 01.
Article in English | MEDLINE | ID: mdl-35789544

ABSTRACT

BACKGROUND: Microsatellite instability-high (MSI-H) subgroup of gastric cancer (GC) is characterized by a high tumor mutational burden, increased lymphocytic infiltration, and enhanced inflammatory cytokines. GC patients with MSI-H status have a good response to immune checkpoint blockade management. However, heterogeneity within the subtype and the underlying mechanisms of shaping tumor microenvironments remain poorly understood. METHODS: RNA expression levels and clinical parameters of GC were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. The data were analyzed using single-sample Gene Set Enrichment Analysis (ssGSEA), univariate Cox regression, multivariate Cox regression, and Least Absolute Shrinkage Selection Operator (LASSO) regression. In addition, multiplex immunohistochemistry (mIHC) was used in our clinical cohort for the tumor microenvironment study. RESULTS: By ssGSEA and survival analysis, the EMT signaling pathway was identified as a representative pathway, which can stratify the patients with MSI-H GC with significant survival predictive power. Then, a novel representative EMT-related five-gene signature (namely CALU, PCOLCE2, PLOD2, SGCD, and THBS2) was established from EMT signaling gene set, which sensitivity and specificity were further validated in the independent GEO database (GSE62254) cohort for disease outcome prediction. Based on public single-cell data and in situ immunohistochemistry, we found that most of these five genes were abundantly expressed in cancer-associated fibroblasts. Furthermore, patients with high or low risk divided by this five-gene signature exhibited a strong correlation of the distinct patterns of tumor immune microenvironment. By mIHC staining of sections from 30 patients with MSI-H status, we showed that the patients with better prognoses had the increased infiltration of CD8+ cells in the primary tumoral tissue. CONCLUSION: Our study developed a simple five-gene signature for stratifying MSI-H GC patients with survival predictive power.


Subject(s)
Cancer-Associated Fibroblasts , Stomach Neoplasms , Humans , Stomach Neoplasms/genetics , Microsatellite Instability , Genes, Regulator , CD8-Positive T-Lymphocytes , Prognosis , Tumor Microenvironment/genetics
7.
Nat Commun ; 13(1): 5413, 2022 09 15.
Article in English | MEDLINE | ID: mdl-36109526

ABSTRACT

Anti-cancer immunity and response to immune therapy is influenced by the metabolic states of the tumours. Immune checkpoint blockade therapy (ICB) is known to involve metabolic adaptation, however, the mechanism is not fully known. Here we show, by metabolic profiling of plasma samples from melanoma-bearing mice undergoing anti-PD1 and anti-CTLA4 combination therapy, that higher levels of purine metabolites, including inosine, mark ICB sensitivity. Metabolic profiles of ICB-treated human cancers confirm the association between inosine levels and ICB sensitivity. In mouse models, inosine supplementation sensitizes tumours to ICB, even if they are intrinsically ICB resistant, by enhancing T cell-mediated cytotoxicity and hence generating an immunologically hotter microenvironment. We find that inosine directly inhibits UBA6 in tumour cells, and lower level of UBA6 makes the tumour more immunogenic and this is reflected in favourable outcome following ICB therapy in human melanomas. Transplanted mouse melanoma and breast cancer cells with genetic ablation of Uba6 show higher sensitivity to ICB than wild type tumours. Thus, we provide evidence of an inosine-regulated UBA6-dependent pathway governing tumour-intrinsic immunogenicity and hence sensitivity to immune checkpoint inhibition, which might provide targets to overcome ICB resistance.


Subject(s)
Immune Checkpoint Inhibitors , Melanoma , Animals , Combined Modality Therapy , Humans , Inosine/pharmacology , Melanoma/pathology , Mice , Radioimmunotherapy , Tumor Microenvironment , Ubiquitin-Activating Enzymes
8.
Cell Death Dis ; 13(7): 577, 2022 07 01.
Article in English | MEDLINE | ID: mdl-35778385

ABSTRACT

The activity of integrin-linked kinase (ILK) in cancerous cells is often oncogenic and associated with malignant properties, such as uncontrolled cell cycle progression and evasion from senescence. However, the role of ILK in cellular senescence in gastric cancer (GC) has not been previously examined. We generated single-cell clones of ILK knock-out using CRISPR-Cas9 in human GC lines with mesenchymal or epithelial histology. Cells with no residual ILK expression exhibited strong cellular senescence with diminished clathrin-mediated endocytosis, Surprisingly, ILK loss-induced cellular senescence appeared to be independent of its function in integrin signaling. The low dose of CPD22, a small molecule inhibitor of ILK activity-induced senescence in three GC cell lines with different histologies. Furthermore, senescent cells with ILK depletion transfected with N-terminal truncated ILK mutant remaining catalytic domains displayed the reduction of senescent phenotypes. RNA sequencing and cytokine array results revealed the enrichment of multiple pro-inflammatory signaling pathways in GC lines in the absence of ILK. Our study identified the important role and the potential mechanism of ILK in the cellular senescence of cancerous epithelial cells. The inhibition of ILK activity using small molecule compounds could have a pro-senescent effect as a therapeutic option for GC.


Subject(s)
Stomach Neoplasms , Cellular Senescence , Humans , Phosphorylation , Protein Serine-Threonine Kinases/genetics , Stomach Neoplasms/genetics
9.
J Periodontal Res ; 57(3): 594-614, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35388494

ABSTRACT

BACKGROUND AND OBJECTIVE: Periodontitis is a multifactorial chronic inflammatory disease that can lead to the irreversible destruction of dental support tissues. As an epigenetic factor, the expression of circRNA is tissue-dependent and disease-dependent. This study aimed to identify novel periodontitis-associated circRNAs and predict relevant circRNA-periodontitis regulatory network by using recently developed bioinformatic tools and integrating sequencing profiling with clinical information for getting a better and more thorough image of periodontitis pathogenesis, from gene to clinic. MATERIAL AND METHODS: High-throughput sequencing and RT-qPCR were conducted to identify differentially expressed circRNAs in gingival tissues from periodontitis patients. The relationship between upregulated circRNAs expression and probing depth (PD) was performed using Spearman's correlation analysis. Bioinformatic analyses including GO analysis, circRNA-disease association prediction, and circRNA-miRNA-mRNA network prediction were performed to clarify potential regulatory functions of identified circRNAs in periodontitis. A receiver-operating characteristic (ROC) curve was established to assess the diagnostic significance of identified circRNAs. RESULTS: High-throughput sequencing identified 70 differentially expressed circRNAs (68 upregulated and 2 downregulated circRNAs) in human periodontitis (fold change >2.0 and p < .05). The top five upregulated circRNAs were validated by RT-qPCR that had strong associations with multiple human diseases, including periodontitis. The upregulation of circRNAs were positively correlated with PD (R = .40-.69, p < .05, moderate). A circRNA-miRNA-mRNA network with the top five upregulated circRNAs, differentially expressed mRNAs, and overlapped predicted miRNAs indicated potential roles of circRNAs in immune response, cell apoptosis, migration, adhesion, and reaction to oxidative stress. The ROC curve showed that circRNAs had potential value in periodontitis diagnosis (AUC = 0.7321-0.8667, p < .05). CONCLUSION: CircRNA-disease associations were predicted by online bioinformatic tools. Positive correlation between upregulated circRNAs, circPTP4A2, chr22:23101560-23135351+, circARHGEF28, circBARD1 and circRASA2, and PD suggested function of circRNAs in periodontitis. Network prediction further focused on downstream targets regulated by circRNAs during periodontitis pathogenesis.


Subject(s)
MicroRNAs , Periodontitis , Computational Biology/methods , Gene Expression Profiling/methods , Gene Regulatory Networks/genetics , Humans , MicroRNAs/genetics , Periodontitis/genetics , RNA, Circular/genetics , RNA, Messenger/genetics
10.
Oncogene ; 41(1): 26-36, 2022 01.
Article in English | MEDLINE | ID: mdl-34667277

ABSTRACT

The EMT (epithelial-to-mesenchymal-transition) subtype of gastric cancer (GC) is associated with poor treatment responses and unfavorable clinical outcomes. Despite the broad physiological roles of the micro-RNA (miR)-200 family, they largely serve to maintain the overall epithelial phenotype. However, during late-stage gastric tumorigenesis, members of the miR-200 family are markedly suppressed, resulting in the transition to the mesenchymal state and the acquisition of invasive properties. As such, the miR-200 family represents a robust molecular marker of EMT, and subsequently, disease severity and prognosis. Most reports have studied the effect of single miR-200 family member knockdown. Here, we employ a multiplex CRISPR/Cas9 system to generate a complete miR-200 family knockout (FKO) to investigate their collective and summative role in regulating key cellular processes during GC pathogenesis. Genetic deletion of all miR-200s in the human GC cell lines induced potent morphological alterations, G1/S cell cycle arrest, increased senescence-associated ß-galactosidase (SA-ß-Gal) activity, and aberrant metabolism, collectively resembling the senescent phenotype. Coupling RNA-seq data with publicly available datasets, we revealed a clear separation of senescent and non-senescent states amongst FKO cells and control cells, respectively. Further analysis identified key senescence-associated secretory phenotype (SASP) components in FKO cells and a positive feedback loop for maintenance of the senescent state controlled by activation of TGF-ß and TNF-α pathways. Finally, we showed that miR-200 FKO associated senescence in cancer epithelial cells significantly recruited stromal cells in the tumor microenvironment. Our work has identified a new role of miR-200 family members which function as an integrated unit serving to link senescence with EMT, two major conserved biological processes.


Subject(s)
Cellular Senescence/immunology , Epithelial-Mesenchymal Transition/immunology , Gene Expression Regulation, Neoplastic/genetics , MicroRNAs/metabolism , Stomach Neoplasms/genetics , Cell Line, Tumor , Cell Proliferation , Humans , Prognosis , Stomach Neoplasms/pathology , Tumor Microenvironment
11.
Oncogene ; 40(48): 6549-6565, 2021 12.
Article in English | MEDLINE | ID: mdl-34663880

ABSTRACT

Mutagenesis is a key hallmark and enabling characteristic of cancer cells, yet the diverse underlying mutagenic mechanisms that shape cancer genomes are not understood. This review will consider the emerging challenge of determining how DNA damage response pathways-both tolerance and repair-act upon specific forms of DNA damage to generate mutations characteristic of tumors. DNA polymerases are typically the ultimate mutagenic effectors of DNA repair pathways. Therefore, understanding the contributions of DNA polymerases is critical to develop a more comprehensive picture of mutagenic mechanisms in tumors. Selection of an appropriate DNA polymerase-whether error-free or error-prone-for a particular DNA template is critical to the maintenance of genome stability. We review different modes of DNA polymerase dysregulation including mutation, polymorphism, and over-expression of the polymerases themselves or their associated activators. Based upon recent findings connecting DNA polymerases with specific mechanisms of mutagenesis, we propose that compensation for DNA repair defects by error-prone polymerases may be a general paradigm molding the mutational landscape of cancer cells. Notably, we demonstrate that correlation of error-prone polymerase expression with mutation burden in a subset of patient tumors from The Cancer Genome Atlas can identify mechanistic hypotheses for further testing. We contrast experimental approaches from broad, genome-wide strategies to approaches with a narrower focus on a few hundred base pairs of DNA. In addition, we consider recent developments in computational annotation of patient tumor data to identify patterns of mutagenesis. Finally, we discuss the innovations and future experiments that will develop a more comprehensive portrait of mutagenic mechanisms in human tumors.


Subject(s)
DNA Damage , DNA Repair , DNA-Directed DNA Polymerase/metabolism , Genome, Human , Genomic Instability , Mutation , Neoplasms/pathology , DNA-Directed DNA Polymerase/genetics , Humans , Neoplasms/genetics
12.
NAR Cancer ; 3(1): zcaa037, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33447826

ABSTRACT

The E3 ubiquitin ligase Rad18 promotes a damage-tolerant and error-prone mode of DNA replication termed trans-lesion synthesis that is pathologically activated in cancer. However, the impact of vertebrate Rad18 on cancer genomes is not known. To determine how Rad18 affects mutagenesis in vivo, we have developed and implemented a novel computational pipeline to analyze genomes of carcinogen (7, 12-Dimethylbenz[a]anthracene, DMBA)-induced skin tumors from Rad18+/+ and Rad18- / - mice. We show that Rad18 mediates specific mutational signatures characterized by high levels of A(T)>T(A) single nucleotide variations (SNVs). In Rad18- /- tumors, an alternative mutation pattern arises, which is characterized by increased numbers of deletions >4 bp. Comparison with annotated human mutational signatures shows that COSMIC signature 22 predominates in Rad18+/+ tumors whereas Rad18- / - tumors are characterized by increased contribution of COSMIC signature 3 (a hallmark of BRCA-mutant tumors). Analysis of The Cancer Genome Atlas shows that RAD18 expression is strongly associated with high SNV burdens, suggesting RAD18 also promotes mutagenesis in human cancers. Taken together, our results show Rad18 promotes mutagenesis in vivo, modulates DNA repair pathway choice in neoplastic cells, and mediates specific mutational signatures that are present in human tumors.

13.
Artif Cells Nanomed Biotechnol ; 45(1): 76-83, 2017 Feb.
Article in English | MEDLINE | ID: mdl-26855181

ABSTRACT

Soft tissue adhesives made from natural hydrogel are attractive in clinical applications due to their excellent properties, such as high water content, good biocompatibility, low immune, good biodegradability. Hydrogels derived from natural polysaccharides and proteins are ideal components for soft tissue adhesive since they resemble the extracellular matrices of the tissue composed of various sugar and amino acids-based macromolecules. In this paper, a series of novel tissue adhesives mixed by aldehyde sodium alginate (ASA) with amino gelatin (AG) were developed and characterized. The effect of aldehyde content in ASA and amino group content in AG on the properties of ASA/AG cross-linked hydrogel was measured. The results showed the gelling time, swelling behavior and the bonding strength of the hydrogel can be tuned by varying the content of aldehyde groups in ASA and the content of amino groups in AG. The gelation time could be controlled within 4-18 min. When the aldehyde content of ASA is 75.24% and the amino content of AG is 0.61 mmol/g, the hydrogel almost has the adhesive strength equal to the commercially available adhesive fibrin glue. So, this tunable ASA/AG hydrogels in this study could be a promising candidate as soft tissue adhesive and have a wide range of biomedical applications.


Subject(s)
Alginates , Hydrogels , Materials Testing , Tissue Adhesives , Alginates/chemistry , Alginates/pharmacology , Animals , Cell Line , Glucuronic Acid/chemistry , Glucuronic Acid/pharmacology , Hexuronic Acids/chemistry , Hexuronic Acids/pharmacology , Hydrogels/chemistry , Hydrogels/pharmacology , Mice , Tissue Adhesives/chemistry , Tissue Adhesives/pharmacology
14.
Int J Biol Macromol ; 96: 569-577, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28017764

ABSTRACT

Recently, photocrosslinked hydrogels have attracted more and more attention in biomedical applications. In this study, a serials of injectable hydrogels were fabricated from aldehyde methacrylate sodium alginate and amino gelatin (AMSA/AG) using a two-step process. Here, sodium alginate, a kind of natural polysaccharide, was modified by oxidizer to form aldehyde sodium alginate (ASA), and methacrylate groups were further grafted on the main chain of ASA. Gelatin, the denatured form of collagen, was modified with ethylenediamine (ED) to graft more amino groups. When AMSA and AG aqueous solutions were mixed, the Schiff base reaction occurred quickly to form the primary network between aldehyde groups in AMSA and amino groups in AG, and then a 365nm ultraviolet (UV) light was used to initiate the radical reaction of methacrylate groups in AMSA to produce the secondary network. The structures and properties of AMSA/AG hydrogels were evaluated by Fourier Transforms Infrared spectroscopy (FTIR) and 1HNMR analysis. The swelling ratio confirmed the density of crosslinked networks, and the mechanical performance demonstrated that the UV initiated the double crosslinking network hydrogels have an improved mechanical properties compared to the single Schiff base networks hydrogels. The results showed that the photocrosslinked double network hydrogels have enhanced mechanical properties, good biocompatibility and controllable degradation rate. So, this hydrogels may have great potential utilized in regenerative medicine as therapeutic materials.


Subject(s)
Alginates/chemistry , Gelatin/chemistry , Hydrogels/chemistry , Hydrogels/pharmacology , Photochemical Processes , Animals , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Cell Line , Cell Proliferation/drug effects , Cell Survival/drug effects , Glucuronic Acid/chemistry , Hexuronic Acids/chemistry , Injections , Mice , Oligopeptides/chemistry , Rheology
15.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 30(11): 1437-1440, 2016 Nov 08.
Article in Chinese | MEDLINE | ID: mdl-29786404

ABSTRACT

OBJECTIVE: To review the recent research progress of acellular fish skin as a tissue engineered scaffold, and to analyze the feasibility and risk management in clinical application. METHODS: The research and development, application status of acellular fish skin as a tissue engineered scaffold were comprehensively analyzed, and then several key points were put forward. RESULTS: Acellular fish skin has a huge potential in clinical practice as novel acellular extracellular matrix, but there have been no related research reports up to now in China. As an emerging point of translational medicine, investigation of acellular fish skin is mainly focused on artificial skin, surgical patch, and wound dressings. CONCLUSIONS: Development of acellular fish skin-based new products is concerned to be clinical feasible and necessary, but a lot of applied basic researches should be carried out.

16.
Article in Chinese | MEDLINE | ID: mdl-26477168

ABSTRACT

OBJECTIVE: To summarize the current research status of alginate derivatives based on biomedical materials, and analyze several key points as novel clinical products. METHODS: The general preparation and application methods of alginate derivatives based on biomedical materials at home and abroad were reviewed. The present status and problems were analyzed. RESULTS: The derivation methods to prepare alginate derivatives include crosslink, sulfation, biological factors derivatization, hydrophobic modification, and graft copolymerization. With excellent bionic performance of structure and properties, many alginate derivatives are available for tissue engineering scaffolds, artificial organs, and drug delivery systems etc. However, more systematic applied basic research data should be collected and statistically analyzed for risk managements. CONCLUSION: Alginate derivatives have good feasibility as novel medical products, meanwhile, systematic evaluation and verification should be executed for their safety, effectiveness, and suitability.


Subject(s)
Alginates , Biocompatible Materials , Tissue Engineering/methods , Tissue Scaffolds , Bone Regeneration , Bone and Bones/metabolism , Bone and Bones/physiopathology , Drug Delivery Systems , Humans
17.
Int J Clin Exp Pathol ; 8(6): 6636-45, 2015.
Article in English | MEDLINE | ID: mdl-26261545

ABSTRACT

Calcium alginate has been proved to favor the skin ulcer healing and collagen synthesis was a critical factor for the wound closure. The present study was to elucidate the mechanism of calcium alginate on the diabetes skin ulceration. Calcium alginate dressing was applied daily on the full-thickness exercising wound created on the back of diabetic rat model as Alg-group (n=6), and the vaseline dressing was used as control (n=6). Rats were respectively sacrificed and the wound tissues were removed and used for the evaluation of various biochemical analysis contained collagen (type I and III) by Western blotting and hydroxyproline level changes by ELISA assay at 3 d, 7 d and 14 d after wounding. The expression of skin collagen I in Alg-group was enhanced from day 3 (0.66 ± 0.25 vs. 0.42 ± 0.09, P<0.05) to day 14 (1.09 ± 0.14 vs. 0.78 ± 0.16, P<0.05). However, no significant difference of collagen III expression was found between two groups during wound healing (P>0.05). And the ratio of collagen I/III in Alg-group was greater than that of Vas-group at day 7 (1.07 ± 0.31 vs. 0.77 ± 0.11, P<0.05) and 14 (1.18 ± 0.30 vs. 0.83 ± 0.14, P<0.05). The hydroxyproline level in skin homogenate of Alg-group was higher than that of Vas-group from day 3 (30.29 ± 0.92 ng/ml vs. 27.52 ± 0.83 ng/ml, P<0.05) to day 14 (89.58 ± 4.97 ng/ml vs. 79.30 ± 4.42 ng/ml, P<0.05). Calcium alginate accelerates the process of wound healing through improving type I collagen synthesis and increasing ratio of collagen I/III in diabetic rats.


Subject(s)
Alginates/pharmacology , Collagen Type III/metabolism , Collagen Type I/metabolism , Diabetes Mellitus, Experimental/complications , Skin Ulcer/drug therapy , Skin/drug effects , Wound Healing/drug effects , Animals , Dose-Response Relationship, Drug , Glucuronic Acid/pharmacology , Hexuronic Acids/pharmacology , Hydroxyproline/metabolism , Male , Rats, Sprague-Dawley , Skin/metabolism , Skin/pathology , Skin Ulcer/etiology , Skin Ulcer/metabolism , Skin Ulcer/pathology , Time Factors
18.
Article in Chinese | MEDLINE | ID: mdl-24796205

ABSTRACT

OBJECTIVE: To review the application status and research progress of alginate dressings. METHODS: The related home and abroad literature was reviewed, and the relevant product standards and regulations were summarized. RESULTS: Alginate dressings have been widely used in clinical because of the characteristics of anti-infection and promoting wound healing. It is mainly used on the wound surface and filled in the wound. Pure alginate dressing is limited in promoting wound healing. A large number of studies are devoted to promoting the activity with other polymer composite to get better dressing. In addition, the industry standards and regulation of alginate dressing products are also gradually improved and standardized. CONCLUSION: Alginate dressing, as an advanced bio-dressing, whose effectiveness has been confirmed, its derivative dressings are also continuously expanding.


Subject(s)
Alginates/chemistry , Alginates/therapeutic use , Anti-Bacterial Agents/therapeutic use , Bandages , Bandages/classification , Bandages/standards , Biological Dressings , Chitosan , Gelatin , Humans , Occlusive Dressings , Quality Control , Silver Compounds , Wound Healing
19.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 27(8): 1015-20, 2013 Aug.
Article in Chinese | MEDLINE | ID: mdl-24171362

ABSTRACT

OBJECTIVE: To review the current situation of alginate-based biomedical materials, especially focus on the clinical strategies and research progress in the clinical applications and point out several key issues that should be concerned about. METHODS: Based on extensive investigation of domestic and foreign alginate-based biomedical materials research and related patent, literature, and medicine producted, the paper presented the comprehensive analysis of its research and development, application status, and then put forward several new research directions which should be focused on. RESULTS: Alginate-based biomedical materials have been widely used in clinical field with a number of patients, but mainly in the fields of wound dressings and dental impression. Heart failure treatment, embolization, tissue engineering, and stem cells culture are expected to become new directions of research and products development. CONCLUSION: Development of alginate-based new products has good clinical feasibility and necessity, but a lot of applied basic researches should be carried out in the further investigations.


Subject(s)
Alginates , Biocompatible Materials , Regenerative Medicine , Tissue Engineering/methods , Alginates/chemistry , Alginates/therapeutic use , Animals , Biocompatible Materials/chemistry , Biocompatible Materials/therapeutic use , Cell Culture Techniques/methods , Embolization, Therapeutic/methods , Glucuronic Acid/chemistry , Glucuronic Acid/therapeutic use , Heart Failure/drug therapy , Heart Failure/therapy , Humans , Hydrogels/chemistry , Hydrogels/therapeutic use , Tissue Engineering/instrumentation , Tissue Scaffolds/chemistry
20.
Article in Chinese | MEDLINE | ID: mdl-21991825

ABSTRACT

OBJECTIVE: To analyze and compare the domestic quality standard and foreign quality standard of sodium hyaluronate (HA), and to expatiate on the critical process monitoring parameters. METHODS: Different quality standards of HA were compared by translating and sorting, and some experimental data were analyzed as well as the manufacturing practice was elaborated. RESULTS: Differences exist in raw materials standard or specifications of products between domestic and foreign, but the basic control points are concordant. CONCLUSION: The company should set up reasonable and controllable quality standard based on quality requirements and related process characteristics so as to assure the safety and effectiveness of the clinical application.


Subject(s)
Biocompatible Materials/standards , Hyaluronic Acid/standards , Quality Control , Safety
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