scholarly journals Facile Preparation of Tunicate-Inspired Chitosan Hydrogel Adhesive with Self-Healing and Antibacterial Properties

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4322
Author(s):  
Xiang He ◽  
Ruyue Liu ◽  
Huiqing Liu ◽  
Ruixiao Wang ◽  
Zhenhao Xi ◽  
...  
Keyword(s):  
Protein A ◽  
Gelation Time ◽  
Antibacterial Properties ◽  
Tissue Adhesive ◽  
Self Healing ◽  
Tissue Adhesion ◽  
E Coli ◽  
Modified Chitosan ◽  
Non Invasive ◽  
Chitosan Hydrogels

In order to replace traditional wound treatments such as sutures, tissue adhesives with strong wet tissue adhesion and biocompatibility have attracted more attention to the applications of non-invasive wound closure. Herein, inspired by tunicate adhesive protein, a series of 2,3,4-trihydroxybenzaldehyde (TBA)-modified chitosan hydrogels (CS-TBA-Fe) were prepared by easily mixing the solutions of chitosan-FeCl3 and TBA via the Schiff-base reaction and the coordination between Fe3+ and pyrogallol groups. The gelation time was greatly shortened to only several seconds after induced even trace Fe3+. The hydrogel (CS-TBA-Fe) exhibited ~12-fold enhanced wet tissue adhesion strength (60.3 kPa) over the commercial fibrin glue. Meanwhile, the hydrogel also showed robust adhesion to various substrates such as wood, PMMA, and aluminum. The swelling ratio and rheological property can be simply controlled by changing the concentrations of chitosan, TBA, and Fe3+. Moreover, the hydrogel displayed a rapid and highly efficient self-healing ability and an excellent antibacterial activity against E. coli. The overall results show that the CS-TBA-Fe hydrogel with enhanced wet adhesiveness will be a promising tissue adhesive material.

scholarly journals Atmospheric Pressure Microplasma for Antibacterial Silver Nanoparticle/Chitosan Nanocomposites With Tailored Properties

2019 ◽  
Author(s):  
Daye Sun ◽  
Jonathan Turner ◽  
Nan Jiang ◽  
Songsong Zhu ◽  
Li Zhang ◽  
...  
Keyword(s):  
Silver Nanoparticle ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Polymer Network ◽  
Antibacterial Properties ◽  
Bacterial Strains ◽  
E Coli ◽  
Modified Chitosan ◽  
First Time

<p>Room temperature atmospheric pressure microplasma (APM) was deployed for the first time for the in situ synthesis of anti-bacterial silver nanoparticle / chitosan (AgNP/CS) nanocomposites. The plasma induced liquid chemistry plays a role in the in situ formation of AgNP, the size distribution of which depends on the silver salt precursor concentration. The microplasma process has also simultaneously tailored the physical properties of the composites, rendering more crosslinked chitosan polymer network with shorter molecular chains. The formation of AgNP within the <i>in situ</i> modified chitosan has led to nanocomposites with overall improved mechanical properties and better stability in simulated body fluid. Our plasma synthesized AgNP/CS nanocomposites also demonstrate effective antibacterial properties against <i>E. Coli</i> and <i>S. Aureus</i> bacterial strains, showing their promise in potential antimicrobial applications.</p>

scholarly journals Atmospheric Pressure Microplasma for Antibacterial Silver Nanoparticle/Chitosan Nanocomposites With Tailored Properties

2019 ◽  
Author(s):  
Daye Sun ◽  
Jonathan Turner ◽  
Nan Jiang ◽  
Songsong Zhu ◽  
Li Zhang ◽  
...  
Keyword(s):  
Silver Nanoparticle ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Polymer Network ◽  
Antibacterial Properties ◽  
Bacterial Strains ◽  
E Coli ◽  
Modified Chitosan ◽  
First Time

<p>Room temperature atmospheric pressure microplasma (APM) was deployed for the first time for the in situ synthesis of anti-bacterial silver nanoparticle / chitosan (AgNP/CS) nanocomposites. The plasma induced liquid chemistry plays a role in the in situ formation of AgNP, the size distribution of which depends on the silver salt precursor concentration. The microplasma process has also simultaneously tailored the physical properties of the composites, rendering more crosslinked chitosan polymer network with shorter molecular chains. The formation of AgNP within the <i>in situ</i> modified chitosan has led to nanocomposites with overall improved mechanical properties and better stability in simulated body fluid. Our plasma synthesized AgNP/CS nanocomposites also demonstrate effective antibacterial properties against <i>E. Coli</i> and <i>S. Aureus</i> bacterial strains, showing their promise in potential antimicrobial applications.</p>

Amino Acid Dependent Performance of Modified Chitosan Against Bacteria and Red Blood Cell

2021 ◽  
Vol 21 (11) ◽  
pp. 5443-5448
Author(s):  
Xiaoyan Ju ◽  
Lu Tian ◽  
Xuantong Duan ◽  
Zhuang Li ◽  
Yongping Han ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Antibacterial Agents ◽  
Molecular Design ◽  
Antibacterial Properties ◽  
E Coli ◽  
Modified Chitosan ◽  
Charged Amino Acids ◽  
Hydrophobic Amino Acids ◽  
Positively Charged

In order to combat antibiotic resistance, the development of new antibacterial agents is essential. In this study, we prepared four types of amino acid modified chitosan (CS-AA). Compared with chitosan modified with hydrophobic amino acids, the chitosan modified with positively charged amino acids showed higher antibacterial efficiency against Escherichia coli (E. coli) under similar grafting rate. CS-AA achieves antibacterial properties mainly by destroying the integrity of bacterial cell membranes. All the four types of CS-AA show low toxicity towards red blood cells. This work indicates that positively charged groups are more important than hydrophobic groups in the design of chitosan-based antibacterial agents, and provides helpful information for the molecular design of effective antibacterial agents.

scholarly journals Escherichia coli interactions with Acanthamoeba: a symbiosis with environmental and clinical implications

2006 ◽  
Vol 55 (6) ◽  
pp. 689-694 ◽  
Author(s):  
Selwa Alsam ◽  
Seok Ryoul Jeong ◽  
James Sissons ◽  
Ricky Dudley ◽  
Kwang Sik Kim ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Legionella Pneumophila ◽  
Protein A ◽  
Acanthamoeba Castellanii ◽  
Laboratory Strain ◽  
Gram Negative Bacteria ◽  
E Coli ◽  
Non Invasive ◽  
Complex Interactions ◽  
K 12

The ability of Acanthamoeba to feed on Gram-negative bacteria, as well as to harbour potential pathogens, such as Legionella pneumophila, Coxiella burnetii, Pseudomonas aeruginosa, Vibrio cholerae, Helicobacter pylori, Listeria monocytogenes and Mycobacterium avium, suggest that both amoebae and bacteria are involved in complex interactions, which may play important roles in the environment and in human health. In this study, Acanthamoeba castellanii (a keratitis isolate belonging to the T4 genotype) was used and its interactions with Escherichia coli (strain K1, a cerebrospinal fluid isolate from a meningitis patient, O18 : K1 : H7, and a K-12 laboratory strain, HB101) were studied. The invasive K1 isolate exhibited a significantly higher association with A. castellanii than the non-invasive K-12 isolate. Similarly, K1 showed significantly increased invasion and/or uptake by A. castellanii in gentamicin protection assays than the non-invasive K-12. Using several mutants derived from K1, it was observed that outer-membrane protein A (OmpA) and LPS were crucial bacterial determinants responsible for E. coli K1 interactions with A. castellanii. Once inside the cell, E. coli K1 remained viable and multiplied within A. castellanii, while E. coli K-12 was killed. Again, OmpA and LPS were crucial for E. coli K1 intracellular survival in A. castellanii. In conclusion, these findings suggest that E. coli K1 interactions with A. castellanii are carefully regulated by the virulence of E. coli.

scholarly journals E. coli Enterotoxin LtB Enhances Vaccine-Induced Anti-H. pylori Protection by Promoting Leukocyte Migration into Gastric Mucus via Inflammatory Lesions

Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 982
Author(s):  
Xiaoyan Peng ◽  
Rongguang Zhang ◽  
Chen Wang ◽  
Feiyan Yu ◽  
Mingyang Yu ◽  
...  
Keyword(s):  
Cellular Immunity ◽  
Protective Efficacy ◽  
Gastric Injury ◽  
Oral Vaccines ◽  
Gastric Mucus ◽  
E Coli ◽  
Non Invasive ◽  
Considerable Impact ◽  
H Pylori

Current studies indicate that the anti-H. pylori protective efficacy of oral vaccines to a large extent depends on using mucosal adjuvants like E. coli heat-lable enterotoxin B unit (LtB). However, the mechanism by which Th17/Th1-driven cellular immunity kills H. pylori and the role of LtB remains unclear. Here, two L. lactis strains, expressing H. pylori NapA and LtB, respectively, were orally administrated to mice. As observed, the administration of LtB significantly enhanced the fecal SIgA level and decreased gastric H. pylori colonization, but also markedly aggravated gastric inflammatory injury. Both NapA group and NapA+LtB group had elevated splenocyte production of IL-8, IL-10, IL-12, IL-17, IL-23 and INF-γ. Notably, gastric leukocytes’ migration or leakage into the mucus was observed more frequently in NapA+LtB group than in NapA group. This report is the first that discusses how LtB enhances vaccine-induced anti-H. pylori efficacy by aggravating gastric injury and leukocytes’ movement into the mucus layer. Significantly, it brings up a novel explanation for the mechanism underlying mucosal cellular immunity destroying the non-invasive pathogens. More importantly, the findings suggest the necessity to further evaluate LtB’s potential hazards to humans before extending its applications. Thus, this report can provide considerable impact on the fields of mucosal immunology and vaccinology.

scholarly journals Injectable Self-Healing Adhesive pH-Responsive Hydrogels Accelerate Gastric Hemostasis and Wound Healing

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Jiahui He ◽  
Zixi Zhang ◽  
Yutong Yang ◽  
Fenggang Ren ◽  
Jipeng Li ◽  
...  
Keyword(s):  
Wound Healing ◽  
Endoscopic Treatment ◽  
Healing Process ◽  
Gelation Time ◽  
Type I ◽  
Self Healing ◽  
Ph Responsive ◽  
Gastric Hemorrhage ◽  
Wound Model ◽  
Arterial Bleeding

AbstractEndoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are well-established therapeutics for gastrointestinal neoplasias, but complications after EMR/ESD, including bleeding and perforation, result in additional treatment morbidity and even threaten the lives of patients. Thus, designing biomaterials to treat gastric bleeding and wound healing after endoscopic treatment is highly desired and remains a challenge. Herein, a series of injectable pH-responsive self-healing adhesive hydrogels based on acryloyl-6-aminocaproic acid (AA) and AA-g-N-hydroxysuccinimide (AA-NHS) were developed, and their great potential as endoscopic sprayable bioadhesive materials to efficiently stop hemorrhage and promote the wound healing process was further demonstrated in a swine gastric hemorrhage/wound model. The hydrogels showed a suitable gelation time, an autonomous and efficient self-healing capacity, hemostatic properties, and good biocompatibility. With the introduction of AA-NHS as a micro-cross-linker, the hydrogels exhibited enhanced adhesive strength. A swine gastric hemorrhage in vivo model demonstrated that the hydrogels showed good hemostatic performance by stopping acute arterial bleeding and preventing delayed bleeding. A gastric wound model indicated that the hydrogels showed excellent treatment effects with significantly enhanced wound healing with type I collagen deposition, α-SMA expression, and blood vessel formation. These injectable self-healing adhesive hydrogels exhibited great potential to treat gastric wounds after endoscopic treatment.

scholarly journals Green Synthesis and Incorporation of Sericin Silver Nanoclusters into Electrospun Ultrafine Cellulose Acetate Fibers for Anti-Bacterial Applications

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1411
Author(s):  
Mujahid Mehdi ◽  
Huihui Qiu ◽  
Bing Dai ◽  
Raja Fahad Qureshi ◽  
Sadam Hussain ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Green Synthesis ◽  
Cellulose Acetate ◽  
Antibacterial Properties ◽  
Vital Role ◽  
Silver Nanoclusters ◽  
Composite Fibers ◽  
E Coli ◽  
Antibacterial Performance ◽  
Field Emission Electron Microscopy

Fiber based antibacterial materials have gained an enormous attraction for the researchers in these days. In this study, a novel Sericin Encapsulated Silver Nanoclusters (sericin-AgNCs) were synthesized through single pot and green synthesis route. Subsequently these sericin-AgNCs were incorporated into ultrafine electrospun cellulose acetate (CA) fibers for assessing the antibacterial performance. The physicochemical properties of sericin-AgNCs/CA composite fibers were investigated by transmission electron microscopy (TEM), field emission electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR) and wide X-ray diffraction (XRD). The antibacterial properties of sericin-AgNCs/CA composite fibers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were systematically evaluated. The results showed that sericin-AgNCs incorporated in ultrafine CA fibers have played a vital role for antibacterial activity. An amount of 0.17 mg/mL sericin-AgNCs to CA fibers showed more than 90% results and elevated upto >99.9% with 1.7 mg/mL of sericin-AgNCs against E. coli. The study indicated that sericin-AgNCs/CA composite confirms an enhanced antibacterial efficiency, which could be used as a promising antibacterial product.

scholarly journals Interaction of Temporin-L Analogues with the E. coli FtsZ Protein

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 704
Author(s):  
Angela Di Somma ◽  
Carolina Canè ◽  
Antonio Moretta ◽  
Angela Duilio
Keyword(s):  
Protein Interactions ◽  
Bacterial Infections ◽  
Antibacterial Properties ◽  
Bacterial Cell Division ◽  
Structural Determinants ◽  
E Coli ◽  
Functional Studies ◽  
Division Process ◽  
Z Ring ◽  
Peptide Complexes

The research of new therapeutic agents to fight bacterial infections has recently focused on the investigation of antimicrobial peptides (AMPs), the most common weapon that all organisms produce to prevent invasion by external pathogens. Among AMPs, the amphibian Temporins constitute a well-known family with high antibacterial properties against Gram-positive and Gram-negative bacteria. In particular, Temporin-L was shown to affect bacterial cell division by inhibiting FtsZ, a tubulin-like protein involved in the crucial step of Z-ring formation at the beginning of the division process. As FtsZ represents a leading target for new antibacterial compounds, in this paper we investigated in detail the interaction of Temporin L with Escherichia coli FtsZ and designed two TL analogues in an attempt to increase peptide-protein interactions and to better understand the structural determinants leading to FtsZ inhibition. The results demonstrated that the TL analogues improved their binding to FtsZ, originating stable protein-peptide complexes. Functional studies showed that both peptides were endowed with a high capability of inhibiting both the enzymatic and polymerization activities of the protein. Moreover, the TL analogues were able to inhibit bacterial growth at low micromolar concentrations. These observations may open up the way to the development of novel peptide or peptidomimetic drugs tailored to bind FtsZ, hampering a crucial process of bacterial life that might be proposed for future pharmaceutical applications.

Preparation of bioactive and antibacterial PMMA-based bone cement by modification with quaternary ammonium and alkoxysilane

2021 ◽  
pp. 088532822110044
Author(s):  
Haiyang Wang ◽  
Toshinari Maeda ◽  
Toshiki Miyazaki
Keyword(s):  
Antibacterial Activity ◽  
Methyl Methacrylate ◽  
Bone Cement ◽  
Setting Time ◽  
Antibacterial Properties ◽  
The Body ◽  
Apatite Formation ◽  
Gram Positive ◽  
E Coli ◽  
Gram Positive Bacteria

Bone cement based on poly(methyl methacrylate) (PMMA) powder and methyl methacrylate (MMA) liquid is a very popular biomaterial used for the fixation of artificial joints. However, there is a risk of this cement loosening from bone because of a lack of bone-bonding bioactivity. Apatite formation in the body environment is a prerequisite for cement bioactivity. Additionally, suppression of infection during implantation is required for bone cements to be successfully introduced into the human body. In this study, we modified PMMA cement with γ-methacryloxypropyltrimetoxysilane and calcium acetate to introduce bioactive properties and 2-( tert-butylamino)ethyl methacrylate (TBAEMA) to provide antibacterial properties. The long-term antibacterial activity is attributed to the copolymerization of TBAEMA and MMA. As the TBAEMA content increased, the setting time increased and the compressive strength decreased. After soaking in simulated body fluid, an apatite layer was detected within 7 days, irrespective of the TBAEMA content. The cement showed better antibacterial activity against Gram-negative E. Coli than Gram-positive bacteria; however, of the Gram-positive bacteria investigated, B. subtilis was more susceptible than S. aureus.

Sign in / Sign up

Export Citation Format

Share Document