Role of crosstalk between synovial cells and chondrocytes in osteoarthritis (Review).

Osteoarthritis (OA) is a low-grade, nonspecific inflammatory disease that affects the entire joint. This condition is characterized by synovitis, cartilage erosion, subchondral bone defects, and subpatellar fat pad damage. There is mounting evidence demonstrating the significance of crosstalk between synovitis and cartilage destruction in the development of OA. To comprehensively explore the phenotypic alterations of synovitis and cartilage destruction, it is important to elucidate the crosstalk mechanisms between chondrocytes and synovial cells. Furthermore, the updated iteration of single-cell sequencing technology reveals the interaction between chondrocyte and synovial cells. In the present review, the histological and pathological alterations between cartilage and synovium during OA progression are described, and the mode of interaction and molecular mechanisms between synovial cells and chondrocytes in OA, both of which affect the OA process mainly by altering the inflammatory environment and cellular state, are elucidated. Finally, the current OA therapeutic approaches are summarized and emerging therapeutic targets are reviewed in an attempt to provide potential insights into OA treatment.

Zhuang-Gu-Fang intervenes vasculogenic and osteogenic coupling in GK rats through Notch1/Noggin/VEGF pathway.

Background: Zhuang-Gu-Fang (ZGF) has been proved to treat osteoporosis in ovariectomized rats by increasing osteogenic related factors Leptin, Ghrelin and Peptide YY(PYY). However, the mechanism of ZGF in the treatment of diabetic osteoporosis (DOP) remains unclear. The aim of this study was to explore the therapeutic effect of ZGF on DOP and its potential molecular mechanism. Methods: Using GK rats as models, the pharmacodynamic effects of ZGF on bone loss were evaluated by hematoxylin-eosin (H&E) staining and micro-computed.tomography (micro-CT). The expression levels of CD31 and endomucin (Emcn) were detected by immunofluorescence to assess the role of ZGF in angiogenic osteogenic coupling. Finally, real-time quantitative PCR (RT-PCR) and Western Blot (WB)were used to detect the expression levels of osteogenic and angiogenesis-related genes and proteins Notch1, Noggin and vascular endothelial growth factor (VEGF). Results: Administration of ZGF demonstrated a significant mitigation of bone loss attributable to elevated glucose levels. H&E staining and micro-CT showed that ZGF notably improved the integrity of the trabecular and cortical bone microarchitecture. Moreover, ZGF was found to augment the density of type H vessels within the bone tissue, alongside elevating the expression levels of Osterix, a transcription factor pivotal for bone formation. Furthermore, our findings suggest that ZGF facilitates the activation of the Notch1/Noggin/VEGF pathway, indicating a potential mechanism through which ZGF exerts its osteoprotective effects. Conclusion: Our results suggest that ZGF potentially facilitates the formation of type H vessels through the Notch1/Noggin/VEGF pathway. This action not only enhances angiogenic-osteogenic coupling but also contributes to the improvement of bone structure and density. Consequently, ZGF emerges as a promising therapeutic agent for the prevention and management of DOP, offering a novel approach by leveraging angiogenesis-dependent osteogenesis.

Comprehensive characterization of Fidgetin on tumor immune microenvironment evaluation and immunotherapy in human hepatocellular carcinoma.

Most cancers have a downregulation of Fidgetin (FIGN), which has been linked to tumor growth. However, there aren't many papers that mention FIGN's connection to hepatocellular carcinoma (HCC). Here, FIGN expression in HCC tissues was markedly reduced as compared to nearby normal liver tissues. According to univariate and multivariate Cox regression, it served as an independent predictor of survival outcomes. Patients with high levels of FIGN expression had a worse outcome. FIGN was shown to be engaged in immune-related pathways and to have a positive correlation with immunological score and immune cells according to KEGG pathway analysis. In HCC patients, FIGN was substantially linked with immunological checkpoints and the hot tumor state. Additionally, immunotherapy and chemotherapy showed a significant therapeutic response in HCC patients with low FIGN expression. This research revealed that FIGN expression was tightly related to hepatoma immunity and might be employed as a biomarker to predict patient prognosis and guide medication.

Transcriptome profile analysis in spinal cord injury rats with transplantation of menstrual blood-derived stem cells.

Introduction: Menstrual blood-derived stem cells (MenSCs) are vital in treating many degenerative and traumatic disorders. However, the underlying molecular mechanisms remain obscure in MenSCs-treating spinal cord injury (SCI) rats. Methods: MenSCs were adopted into the injured sites of rat spinal cords at day 7 post surgery and the tissues were harvested for total RNA sequencing analysis at day 21 after surgery to investigate the expression patterns of RNAs. The differentially expressed genes (DEGs) were analyzed with volcano and heatmap plot. DEGs were sequentially analyzed by weighted gene co-expression network, functional enrichment, and competitive endogenous RNAs (ceRNA) network analysis. Next, expression of selected miRNAs, lncRNAs, circRNAs and mRNAs were validated by quantitative real-time polymerase chain reaction (qRT-PCR). Bioinformatics packages and extra databases were enrolled to scoop the genes functions and their interaction relationships. Results: A total of 89 lncRNAs, 65 circRNAs, 120 miRNAs and 422 mRNAs were significantly upregulated and 65 lncRNAs, 72 circRNAs, 74 miRNAs, and 190 mRNAs were significantly downregulated in the MenSCs treated rats compared to SCI ones. Current investigation revealed that MenSCs treatment improve the recovery of the injured rats and the most significantly involved pathways in SCI regeneration were cell adhesion molecules, nature killer cell mediated cytotoxicity, primary immunodeficiency, chemokine signaling pathway, T cell receptor signaling pathway and B cell receptor signaling pathway. Moreover, the lncRNA-miRNA-mRNA and circRNA-miRNA-mRNA ceRNA network of SCI was constructed. Finally, the protein-protein interaction (PPI) network was constructed using the top 100 DE mRNAs. The constructed PPI network included 47 nodes and 70 edges. Discussion: In summary, the above results revealed the expression profile and potential functions of differentially expressed (DE) RNAs in the injured spinal cords of rats in the MenSCs-treated and SCI groups, and this study may provide new clues to understand the mechanisms of MenSCs in treating SCI.

Application of radiomics model based on lumbar computed tomography in diagnosis of elderly osteoporosis.

A metabolic bone disease characterized by decreased bone formation and increased bone resorption is osteoporosis. It can cause pain and fracture of patients. The elderly are prone to osteoporosis and are more vulnerable to osteoporosis. In this study, radiomics are extracted from computed tomography (CT) images to screen osteoporosis in the elderly. Collect the plain scan CT images of lumbar spine, cut the region of interest of the image and extract radiomics features, use Lasso regression to screen variables and adjust complexity, use python language to model random forests, support vector machines, K nearest neighbor, and finally use receiver operating characteristic curve to evaluate the performance of the model, including precision, recall, accuracy and area under the curve (AUC). For the model, 14 radiolomics features were selected. The diagnosis performance of random forest model and support vector machine is good, all around 0.9. The AUC of K nearest neighbor model in training set and test set is 0.828 and 0.796, respectively. We selected the plain scan CT images of the elderly lumbar spine to build radiomics features model, which has good diagnostic performance and can be used as a tool to assist the diagnosis of osteoporosis in the elderly.

NEK6 Promotes the Progression of Osteosarcoma Through Activating STAT3 Signaling Pathway by Down-Regulation of miR-26a-5p.

Background: Osteosarcoma is a malignant tumor originating from the skeletal system. There is no effective treatment other than surgery and chemotherapy, which seriously endangers the health of children and adolescents. NEK6 is a novel discovered Serine/Threonine protein kinase that can regulate cell cycle and activate several oncogenic pathways. Methods: NEK6 expression in pan-cancer including sarcoma was evaluated using analysis tools of TIMER, UALCNA and GEPIA with TCGA database, and its association with overall survival in patients with sarcoma was also analyzed. TargetScan, tarbase, microT-CDS and Starbase online software were used to predict NEK6-targeted miRNAs, including miR-26a-5p. Tumor tissues from patients with osteosarcoma were collected for NEK6 and miRNA detection using RT-qPCR. NEK6 down-regulated by siRNAs or miR-26a-5p in osteosarcoma cells was detected by RT-qPCR, Western blot and Immunofluorescence staining assays. Effects of NEK6 knockdown on proliferation, migration, invasion and apoptosis of osteosarcoma cells were detected by CCK-8, wound healing, transwell and flow cytometry, respectively. The expressions of STAT3, metastasis and apoptosis-related genes were detected by Western blot. Results: High expression of NEK6 and low expression of miR-26a-5p were lowly expressed in osteosarcoma and they were negative correlation. NEK6 has been confirmed as a direct target for miR-26a-5p. In addition, NEK6 down-regulated by siRNAs or miR-26a-5p led to inhibition of cell proliferation, migration and invasion while promoting cell apoptosis. The levels of phosphorylated STAT3 and metastasis genes (MMP-2, MMP-9) were inhibited, while apoptotic gene Bax was promoted and Bcl2 was inhibited by miR-26a-5p upregulation. Conclusion: NEK6 can promote osteosarcoma progression via activating STAT3 signaling pathway, which is inhibited by miR-26a-5p, suggesting that NEK6 is a potential oncogene and miR-26a-5p is a suppressor of osteosarcoma. The strategy of inhibiting of NEK6 by miR-26a-5p may be an effective approach for osteosarcoma therapy.

TTC4 inhibits NLRP3 inflammation in rheumatoid arthritis by HSP70.

OBJECTIVE: This experiment explored the function of TTC4 in rheumatoid arthritis inflammation and its possible mechanism. METHODS: C57BL/6 mice were immunized intradermally with bovine type II collagen. Lipopolysaccharide induction was performed on RAW264.7 cells. RESULTS: The mRNA expression of TTC4 in articular tissue of mice with rheumatoid arthritis was downregulated. Sh-TTC4 virus increased arthritis score, morphological change score, paw edema, and spleen index, as well as alkaline phosphatase level in mice with rheumatoid arthritis. Sh-TTC4 virus increased the levels of inflammatory factors and MDA, and decreased anti-oxidant factors in articular tissue of mice with rheumatoid arthritis. TTC4 reduced inflammation and oxidative stress in an in vitro model. TTC4 regulated HSP70 in a rheumatoid arthritis model. The inhibition of HSP70 reduced the effects of sh-TTC4 gene in mice with rheumatoid arthritis. METTL3 reduced the stability of the TTC4 gene. CONCLUSION: In this study, the TTC4 gene reduced oxidative response and inflammation in the rheumatoid arthritis model through the HSP70/NLRP3 pathway. Therefore, it can be concluded that TTC4 can be used as diagnosis and prognosis evaluation of rheumatoid arthritis.

Aldehyde-functionalized cellulose as reactive sorbents for the capture and retention of polyamine odor molecules associated with chronic wounds.

Aldehyde-functionalized cellulose (AFC) was prepared by oxidizing cellulose with sodium metaperiodate. The reaction was characterized by Schiff's test, FT-IR, and UV-vis study. AFC was evaluated as a reactive sorbent for controlling polyamine-based odor from chronic wounds, and its performance was compared with charcoal, one of the most widely utilized odor-control sorbents through physisorption. Cadaverine was used as the model odor molecule. A liquid chromatography/mass spectrometry (LC/MS) method was established to quantify the compound. AFC was found to rapidly react with cadaverine through the Schiff-base reaction, which was confirmed by FT-IR, visual observation, CHN elemental analysis, and the ninhydrin test. The sorption and desorption behaviors of cadaverine onto AFC were quantified. With clinic-relevant cadaverine concentrations, AFC demonstrated much better sorption performance than charcoal. At even higher cadaverine concentrations charcoal showed higher sorption capacity, probably due to its high surface area. On the other hand, in desorption studies, AFC retained much more of the sorbed cadaverine than charcoal. When AFC and charcoal were combined, the pair demonstrated excellent sorption and desorption behaviors. The XTT (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) assay confirmed that AFC has very good in vitro biocompatibility. These results suggest that AFC-based reactive sorption can be a new strategy to control odors associated with chronic wounds for improved healthcare.

An attenuated strain of cyprinid herpesvirus 2 as a vaccine candidate against herpesviral hematopoietic necrosis disease in gibel carp, Carassius auratus gibelio.

Herpesviral hematopoietic necrosis disease causes by cyprinid herpesvirus 2 (CyHV-2) infection is a high mortality disease that leads to great economic damage to gibel carp, Carassius auratus gibelio aquaculture. In this study, an attenuated strain of CyHV-2 G-RP7 was achieved by subculture on RyuF-2 cells derived from the fin of Ryukin-variety goldfish and GiCF cells derived from fin of gibel carp. As the attenuated vaccine candidate, there are no clinical symptoms of gibel carp that immersion or intraperitoneal injection with G-RP7 strain. The protection rates of G-PR7 to gibel carp by immersion and intraperitoneal injection were 92% and 100%, respectively. In the test for virulence reversion, the candidate was propagated through gibel carp six times by intraperitoneal injection with kidney and spleen homogenate of the inoculated fish. During in vivo passages in gibel carp, no abnormality and mortality of the inoculated fish were observed, and the virus DNA copies maintain a low level from the first passage to the sixth passage. The dynamic of virus DNA in each tissue of G-RP7 vaccination fish increased within 1, 3, and 5 days post-immunization, and subsequently decreased and stabilized within 7 and 14 days. In addition, the increase of anti-virus antibody titer was detected both immersion and injection immunization fish 21 days after vaccination by ELISA. These results demonstrated that G-RP7 can be a promising live attenuated vaccine candidate against the disease.

Role of macrophage polarization in osteoarthritis (Review).

Osteoarthritis (OA) is a disease involving the whole joint that seriously reduces the living standards of individuals. Traditional treatments include physical therapy, administration of anti-inflammatory and analgesic drugs and injection of glucocorticoids or hyaluronic acid into the joints. However, these methods have limited efficacy and it is difficult to reverse the progression of OA, therefore it is urgent to find new effective treatment methods. Immune microenvironment is significant in the occurrence and development of OA. Recent studies have shown that macrophages are important targets for the treatment of OA. Macrophages are polarized into M1 pro-inflammatory phenotype and M2 anti-inflammatory phenotype under stimulation of different factors, which release and regulate inflammatory response and cartilage growth. Accumulating studies have tried to alleviate OA by regulating macrophage homeostasis. The present study summarized the related studies, discuss the mechanism of various therapeutic reagents on OA, expound the molecular mechanism of drug effect on OA and attempted to provide clues for the treatment of OA.

Transcriptomic Analysis of Vibrio parahaemolyticus Underlying the Wrinkly and Smooth Phenotypes.

Vibrio parahaemolyticus, a causative agent of seafood-associated gastroenteritis, undergoes opaque-translucent (OP-TR) colony switching associated with capsular polysaccharide (CPS) production. Here, we showed that V. parahaemolyticus was also able to naturally and reversibly switch between wrinkly and smooth phenotypes. More than 1,000 genes were significantly differentially expressed during colony morphology switching, including the major virulence gene loci and key biofilm-related genes. The genes responsible for type III secretion system 1 (T3SS1), type VI secretion systems (T6SS1 and T6SS2), and flagellar synthesis were downregulated in the wrinkly spreader phenotype, whereas genes located on the pathogenicity island Vp-PAI and those responsible for chitin-regulated pili (ChiRP) and Syp exopolysaccharide synthesis were upregulated. In addition, we showed that the wrinkly spreader grew faster, had greater motility and biofilm capacities, and produced more c-di-GMP than the smooth type. A dozen genes potentially associated with c-di-GMP metabolism were shown to be significantly differentially expressed, which may account for the differences in c-di-GMP levels between the two phenotypes. Most importantly, dozens of putative regulators were significantly differentially expressed, and hundreds of noncoding RNAs were detected during colony morphology switching, indicating that phenotype switching is strictly regulated by a complex molecular regulatory network in V. parahaemolyticus. Taken together, the presented work highlighted the gene expression profiles related to wrinkly-smooth switching, showing that the significantly differentially expressed genes were involved in various biological behaviors, including virulence factor production, biofilm formation, metabolism, adaptation, and colonization. IMPORTANCE We showed that Vibrio parahaemolyticus was able to naturally and reversibly switch between wrinkly and smooth phenotypes and disclosed the gene expression profiles related to wrinkly-smooth switching, showing that the significantly differentially expressed genes between the two colony morphology phenotypes were involved in various biological behaviors, including virulence factor production, biofilm formation, metabolism, adaptation, and colonization.

An Eco-Friendly Conversion of Aquaculture Suspended Solid Wastes Into High-Quality Fish Food by Improving Poly-ß-Hydroxybutyrate Production.

The aquaculture industry is vital in providing a valuable protein food source for humans, but generates a huge amount of solid and dissolved wastes that pose great risks to the environment and aquaculture sustainability. Suspended solids (in short SS), one of the aquaculture wastes, are very difficult to be treated due to their high organic contents. The bioconversion from wastewater, food effluents, and activated sludge into poly-ß-hydroxybutyrate (PHB) is a sustainable alternative to generate an additional income and could be highly attractive to the agricultural and environmental management firms. However, little is known about its potential application in aquaculture wastes. In the present study, we first determined that 7.2% of SS was PHB. Then, the production of PHB was increased two-fold by the optimal fermentation conditions of wheat bran and microbial cocktails at a C/N ratio of 12. Also, the PHB-enriched SS showed a higher total ammonia nitrogen removal rate. Importantly, we further demonstrated that the PHB-enriched SS as a feed could promote fish growth and up-regulate the expression of the immune-related genes. Our study developed an eco-friendly and simple approach to transforming problematic SS wastes into PHB-enriched high-quality food for omnivorous fish, which will increase the usage efficiency of SS and provide a cheaper diet for aquatic animals.

Upregulation of P2Y12 inhibits chondrocyte apoptosis in lumbar osteoarthritis through the PI3K/AKT signaling pathway.

Lumbar facet osteoarthritis (FJOA) is a major cause of severe lower back pain and disability worldwide. However, the mechanism underlying cartilage degeneration in FJOA remains unclear. The purpose of this study was to investigate the regulation and mechanism of P2Y12 on chondrocyte apoptosis in FJOA. The experimental rats were randomly divided into non-operation (n = 20) and operation groups (n = 20). In the operation group, Sodium iodoacetate (MIA, Sigma, 200 mg/mL) was injected into the right L4/5 facet process using a blunt nanoneedle 26 (WPI, Sarasota, FL, USA) under the control of an injection pump. The final injection volume was 5µL and the injection rate was 2µL/min. The facet joint was removed four weeks after surgery. After the operation, samples were stored at -80 °C until further use, whereby the right facet joints in each group were tested. Hematoxylin and eosin (HE) and iron-red solid green staining were used to observe the degeneration of articular chondrocytes in rats. Immunohistochemistry and western blotting were used to observe the expressions of P2Y12, Matrix metalloproteinase 13 (MMP13), Collagen II (COL2), and other cartilage degeneration and apoptosis-related genes. Co-localization of P2Y12-cleaved caspase-3 in the apoptosis model was detected by dual-standard immunofluorescence staining. Apoptosis was also detected by flow cytometry and TUNEL assay.P2Y12 is highly expressed in OA cartilage tissue, and inhibits IL-1ß -induced chondrocyte apoptosis through PI3K/AKT signaling pathway, thus playing a certain protective role on cartilage.

BAG3 protects chondrocytes against lumbar facet joint osteoarthritis by regulating autophagy and apoptosis.

Bcl2-associated athanogene3 (BAG3) protein, mainly induced by stressful stimuli, has been confirmed to participate in apoptosis and autophagy. In recent studies, BAG3 has gradually become a key molecule in tumors. However, the role of BAG3 in the progression of lumbar facet joint osteoarthritis (FJOA) and whether it can regulate chondrocyte apoptosis and autophagy are still unknown. In both human and FJOA rat models, we observed an upregulation of BAG3 and apoptosis and autophagy-related proteins compared with healthy tissues. Then, we established the chondrocytes injury model in vitro by using IL-1ß to stimulate human SW1353 cells. Western blot analysis data showed significant expression of BAG3, apoptosis, and autophagy-related proteins in SW1353 cells. Finally, by knocking down and overexpressing BAG3, we discovered possible anti-apoptotic and autophagy-promoted effects of BAG3 in FJOA through various experimental methods. This study demonstrated that BAG3 actively participates in regulating chondrocyte apoptosis and autophagy in FJOA and may be a highly interesting target for pharmacological interventions.

Expression and regulatory network of long noncoding RNA in rats after spinal cord hemisection injury.

Long noncoding RNAs (lncRNAs) participate in a variety of biological processes and diseases. However, the expression and function of lncRNAs after spinal cord injury has not been extensively analyzed. In this study of right side hemisection of the spinal cord at T10, we detected the expression of lncRNAs in the proximal tissue of T10 lamina at different time points and found 445 lncRNAs and 6522 mRNA were differentially expressed. We divided the differentially expressed lncRNAs into 26 expression trends and analyzed Profile 25 and Profile 2, the two expression trends with the most significant difference. Our results showed that the expression of 68 lncRNAs in Profile 25 rose first and remained high 3 days post-injury. There were 387 mRNAs co-expressed with the 68 lncRNAs in Profile 25. The co-expression network showed that the co-expressed genes were mainly enriched in cell division, inflammatory response, FcγR-mediated cell phagocytosis signaling pathway, cell cycle and apoptosis. The expression of 56 lncRNAs in Profile2 first declined and remained low after 3 days post-injury. There were 387 mRNAs co-expressed with the 56 lncRNAs in Profile 2. The co-expression network showed that the co-expressed genes were mainly enriched in the chemical synaptic transmission process and in the signaling pathway of neuroactive ligand-receptor interaction. The results provided the expression and regulatory network of the main lncRNAs after spinal cord injury and clarified their co-expressed gene enriched biological processes and signaling pathways. These findings provide a new direction for the clinical treatment of spinal cord injury.

Network analysis of population flow among major cities and its influence on COVID-19 transmission in China.

Large-scale and diffuse population flow amplifies the localized COVID-19 outbreak into a widespread pandemic. Network analysis provides a new methodology to uncover the topology and evolution of the population flow and understand its influence on the early dynamics of COVID-19 transmission. In this paper, we simulated 42 transmission scenarios to show the distribution of the COVID-19 outbreak across China. We predicted some original (Guangzhou, Shanghai, Shenzhen) had higher total aggregate population outflows than Wuhan, indicating larger spread scopes and faster growth rates of COVID-19 outbreak. We built an importation risk model to identify some major cities (Dongguan and Foshan) with the highest total importation risk values and the highest standard deviations, indicating the core transmission chains (Dongguan-Shenzhen, Foshan-Guangzhou). We built the population flow networks to analyze their Spatio-temporal characteristics and identify the influential sub-groups and spreaders. By removing different influential spreaders, we identified Guangzhou can most influence the network's topological characteristics, and some major cities' degree centrality was significantly decreased. Our findings quantified the effectiveness of travel restrictions on delaying the epidemic growth and limiting the spread scope of COVID-19 in China, which helped better derive the geographical COVID-19 transmission related to population flow networks' structural features.

Knockdown of TRAF6 inhibits chondrocytes apoptosis and inflammation by suppressing the NF-κB pathway in lumbar facet joint osteoarthritis.

Tumor necrosis factor receptor-associated factor 6 (TRAF6), a regulator of NF-κB signaling, has been discovered recently to be probably related to osteoarthritis, while the function of TRAF6 in lumbar facet joint osteoarthritis(FJOA)still remains unknown. The aim of this study was to probe the specific function of TRAF6 in chondrocytes and its connection with the pathophysiology of FJOA. We found upregulation of TRAF6 in FJOA cartilage by western blot analysis. In vitro, we stimulated immortalized human chondrocytes by LPS to establish the cells apoptosis model. Western blot analysis demonstrated that levels of TRAF6 and cleaved caspase-3/8 in the chondrocyte injury model increased significantly. Knockdown of TRAF6 suppressed the expression of matrix metallopeptidase-13 (MMP-13) and interleukin-6 (IL-6) induced by LPS, and alleviated cell apoptosis. Meanwhile, western blot and immunofluorescent staining demonstrated that IκBα degradation and p65 nuclear transportation were also inhibited, revealing that knockdown of TRAF6 suppressed activation of the NF-κB pathway in LPS-induced chondrocytes apoptosis model. Collectively, our findings suggest that TRAF6 plays a crucial role in FJOA development by regulating NF-κB signaling pathway. Knockdown of TRAF6 may supply a potential therapeutic strategy for FJOA.

Cyanuric Chloride-Based Reactive Dyes for Use in the Antimicrobial Treatments of Polymeric Materials.

This study reports a simple and practical method to introduce antimicrobial and biofilm-controlling functions into hydroxyl- or amino-containing polymers such as cellulose using compounds derived from widely used reactive dyes. Two dichloro-s-triazine-based dyes, reactive blue 4 and sodium 4-(4,6-dichloro-1,3,5-triazinylamino)-benzenesulfonate (a colorless reactive "dye"), were covalently attached to cellulose at room temperature by replacing one chloride on the dyes with the hydroxyl groups on cellulose followed by hydrolysis under alkaline conditions to transform the remaining chloride into hydroxyl groups. The chemical reactions were confirmed by FT-IR studies, energy-dispersive X-ray spectroscopy, water contact angle measurement, and zeta potential analysis. The resulting cellulose provided powerful antimicrobial activities against Staphylococcus epidermidis (S. epidermidis, ATCC 35984, Gram-positive bacteria), Escherichia coli (E. coli, ATCC 15597, Gram-negative bacteria), and Candida albicans (C. albicans, ATCC 10231, yeast) and effectively prevented the formation of bacterial or fungal biofilms. The minimum inhibition concentrations of the hydrolyzed dyes were similar to that of phenol. In the zone of inhibition studies using phenolic compounds as positive controls, the hydrolyzed dyes and their model compound cyanuric acid demonstrated antimicrobial functions, suggesting that the antimicrobial activities were associated with the phenol-like hydroxyl groups on the triazine rings. Antimicrobial mechanism investigation indicated that the phenol-like structures on the dyed cellulose caused microbial lysis and leakage of intracellular components. The antimicrobial functions were durable upon repeated washing, and the dyed cellulose showed outstanding biocompatibility toward mammalian cells.

Enhanced antimicrobial and antifungal property of two-dimensional fibrous material assembled by N-halamine polymeric electrolytes.

Microbial contamination and biofilm formation cause serious issues in medical, household, industrial and environmental applications. In this study, a series of cationic and anionic N-halamine polymeric precursors, poly (N,N-dimethyl-N-decyl ammonium ethyl methacrylate-co-methacrylamide) (PQDM) and poly (acrylic acid-co-methacrylamide) (PAM), were synthesized and coated onto cotton fabrics through the layer-by-layer (LBL) assembly technique. The coated LBL cotton swatches were characterized by Scanning Electron Microscopy, Fourier transform infrared spectroscopy, and contact angle evaluation. The stability of the LBL samples towards artificial sweat and home laundering was evaluated. The LBL treated fabrics demonstrated effective antimicrobial efficacy and biofilm-controlling against Gram-positive bacteria, Gram-negative bacteria, and Fungi. In vitro cytocompatibility test towards mouse fibroblast cell indicated that the LBL coated cotton fabrics are cytocompatible, pointing to great potentialities of the LBL assembled fabrics for future biomedical applications.