Effects of Different Factors on Antibacterial Properties of Crosslinked Chitosan-Coated Ag-Loading Nano-SiO2 Composites

2012 ◽  
Vol 535-537 ◽  
pp. 51-54
Author(s):  
Li Zhang ◽  
Mei Niu ◽  
Jin Ming Dai ◽  
Li Qiao Wei ◽  
Xu Guang Liu ◽  
...  

Chitosan (CTS) and Ag-loading nano-SiO2 (SLS) are excellent antibacterial materials. However, when used alone, these monocomponent antibacterial agents are sometimes far from meeting requirements in special conditions. In this study, crosslinked chitosan-coated Ag-loading nano-SiO2 composites (CCTS-SLS) were synthesized by adsorption crosslinking reaction. Then Escherichia coil (ATCC 8099) was taken as the experimental bacteria for antibacterial tests. The experimental results indicate that the mass ratio of SLS to chitosan had the greatest influences on the value of MIC (minimal inhibitory concentration) for CCTS-SLS composite. However, the heating temperature had a weak influence on the antibacterial performance of CCTS-SLS composite.

2013 ◽  
Vol 815 ◽  
pp. 333-338
Author(s):  
Ming Li Liu ◽  
Chun Feng Li ◽  
Yun Long Wang ◽  
Kai Lu ◽  
Jiu Yin Pang ◽  
...  

This study used Ag-embedded nanoTiO2, xylan and water-soluble Chitosan as antibacterial agents, respectively prepared shutter blades through the treating solution of the different concentration and the different drug loading amount of the poplar veneer. Through a single factor experiment, this paper analyzes that the different antibacterial agent, concentration of antibacterial agent and the drug loading amount have an effect on the antibacterial properties of the shutter blades. The results show that the order of antibacterial performance of the shutter blades impregnated antibacterial agents is the Ag-embedded nanoTiO2, Chitosan, Xylan. Comprehensiv-ely thought the antibacterial properties and economic index, the optimal concentration of the Ag-embedded nanoTiO2 impregnation solution is 1%.


2020 ◽  
pp. 56-64
Author(s):  
A Molanaei ◽  
SA Seyedoshohadaei ◽  
S Hasani ◽  
P Sharifi ◽  
M Rashidian ◽  
...  

Introduction: Bacterial resistance to antibacterial agents is a very serious threat to public health. Where some antibacterial agents prove ineffective, the antibacterial properties of honey have been shown to be highly efficacious against several human bacterial pathogens. The purpose of this study is to investigate the sensitivity of Staphylococcus aureus isolated from the nursing staff of a hospital to natural honey. Methods: In this study, 35 strains of methicillin-resistant S. aurous samples were selected from hospital staff's nasal swabs. Two strains were vancomycin-resistant. The serial dilution tube test methodwas used to determine minimum inhibitory concentration (MIC) .The susceptibility of each strain of staph bacteria to natural honey without wax was determined and compared with that of a glucose solution with the same density. Results: In all strains, except for the two strains resistant to vancomycin, MIC level was < 8.3% (v/v). The MIC of glucose as dense as honey was four times higher. The two vancomycin-resistant strains were completely resistant to natural honey. Conclusions: This study has therefore demonstrated that inhibiting bacterial growth is not merely done by purely natural honey not because of osmolality, but vancomycin-resistant bacteria are not sensitive to natural honey. Keywords: sensitivity, Staphylococcus aurous, natural honey, minimum inhibitory concentration


2021 ◽  
Vol 1 (1) ◽  
pp. 44-52
Author(s):  
Nur ‘Afini Ismail ◽  
Kamyar Shameli ◽  
Roshafima Rasit Ali ◽  
Siti Nur Amalina Mohamad Sukri ◽  
Eleen Dayana Mohamed Isa

Due to their biocidal activity properties, graphene based materials have been widely studied especially in biomedical, agriculture and water treatment process which focus on mitigating the microbial resistance problem. However, the antibacterial performance of these materials alone are relatively weak and need to be improved in order to enhance their biological activity. Copper nanoparticles is a low cost metal also has the antibacterial properties which is almost similar with the silver and gold nanoparticles. The combination of these two materials had produced to a new potential material as another alternative for the antibacterial agents. Therefore, in this work, a brief review of copper/graphene based material nanocomposites and their antibacterial study was discussed.


2020 ◽  
Vol 17 (1) ◽  
pp. 71-84
Author(s):  
Riham M. Bokhtia ◽  
Siva S. Panda ◽  
Adel S. Girgis ◽  
Hitesh H. Honkanadavar ◽  
Tarek S. Ibrahim ◽  
...  

Background: Bacterial infections are considered as one of the major global health threats, so it is very essential to design and develop new antibacterial agents to overcome the drawbacks of existing antibacterial agents. Method: The aim of this work is to synthesize a series of new fluoroquinolone-3-carboxamide amino acid conjugates by molecular hybridization. We utilized benzotriazole chemistry to synthesize the desired hybrid conjugates. Result: All the conjugates were synthesized in good yields, characterized, evaluated for their antibacterial activity. The compounds were screened for their antibacterial activity using methods adapted from the Clinical and Laboratory Standards Institute. Synthesized conjugates were tested for activity against medically relevant pathogens; Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27856) Staphylococcus aureus (ATCC 25923) and Enterococcus faecalis (ATCC 19433). Conclusion: The observed antibacterial experimental data indicates the selectivity of our synthesized conjugates against E.Coli. The protecting group on amino acids decreases the antibacterial activity. The synthesized conjugates are non-toxic to the normal cell lines. The experimental data were supported by computational studies.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1411
Author(s):  
Mujahid Mehdi ◽  
Huihui Qiu ◽  
Bing Dai ◽  
Raja Fahad Qureshi ◽  
Sadam Hussain ◽  
...  

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.


Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 321
Author(s):  
Shekh Sabir ◽  
Tsz Tin Yu ◽  
Rajesh Kuppusamy ◽  
Basmah Almohaywi ◽  
George Iskander ◽  
...  

The quorum sensing (QS) system in multi-drug-resistant bacteria such as P. aeruginosa is primarily responsible for the development of antibiotic resistance and is considered an attractive target for antimicrobial drug discovery. In this study, we synthesised a series of novel selenourea and thiourea-containing dihydropyrrol-2-one (DHP) analogues as LasR antagonists. The selenium DHP derivatives displayed significantly better quorum-sensing inhibition (QSI) activities than the corresponding sulphur analogues. The most potent analogue 3e efficiently inhibited the las QS system by 81% at 125 µM and 53% at 31 µM. Additionally, all the compounds were screened for their minimum inhibitory concentration (MIC) against the Gram-positive bacterium S. aureus, and interestingly, only the selenium analogues showed antibacterial activity, with 3c and 3e being the most potent with a MIC of 15.6 µM.


2021 ◽  
Vol 10 (1) ◽  
pp. 478-487
Author(s):  
Yu Liu ◽  
Heliang Wang ◽  
Xiwei Guo ◽  
Mingyuan Yi ◽  
Lihong Wan ◽  
...  

Abstract With the emerging of sustainability, the fabrication of effective and eco-friendly agents for rubber industry has attracted extensive attention. In this study, a novel and nontoxic titanium dioxide-based vulcanization accelerator (xanthate-modified nanotitanium dioxide (TDSX)) with excellent antibacterial performance, for the first time, was synthesized under the catalyst of ceric ammonium nitrate. Notably, the thermal stability of xanthate was greatly enhanced after being grafted on titanium dioxide (TiO2) nanoparticles, in which the activation energy was increased from 6.4 to 92.5 kJ/mol, enabling the obtained TDSX with multiple functions, mainly consisting of fabulous vulcanization-promoting effects, reinforcing effects, antibacterial properties, and anti-ultraviolet aging effects for natural rubber (NR). Simultaneously, the TDSX can be effectively and uniformly dispersed in the rubber matrix along with the developed interface interaction between TDSX particles and rubber matrix. Compared to the traditional accelerators 2-mercaptobenzothiazole (M) system, the tensile strength and the tearing strength of NR/TDSX was improved by 26.3 and 40.4%, respectively. Potentially, our work for preparing green vulcanization accelerator can provide a new design strategy for multifunctional high performance elastomer materials.


2018 ◽  
Vol 83 (1) ◽  
pp. 10402
Author(s):  
Janusz Typek ◽  
Nikos Guskos ◽  
Grzegorz Zolnierkiewicz ◽  
Zofia Lendzion-Bielun ◽  
Anna Pachla ◽  
...  

Nanocomposites of Fe3O4 nanoparticles (NPs) impregnated with silver NPs display antibacterial properties and may be used in water treatment as disinfection agent. Three samples were synthesized: Fe3O4 NPs obtained by the precipitation method and additionally two samples with added silver NPs with mass ratio of Ag:Fe3O4 equal to 1:100 and 2:100. Magnetic properties of these samples were studied by SQUID magnetometry (in temperature range 2–300 K and magnetic fields up to 70 kG) and magnetic resonance technique at RT. Temperature dependence of dc susceptibility revealed the blocking temperature close to RT in all three samples and allowed to determine the presence of single or multi-mode distribution of NP sizes in a particular sample. Isothermal magnetisation measurements showed that the presence of silver NPs, especially those with smaller sizes, decreases the saturation magnetisation. The shape of ferromagnetic loop registered at T = 2 K was used to discuss the sizes of NP magnetic clusters in our samples. Conclusions obtained from analysis of the ferromagnetic resonance spectra were consistent with the propositions based on the magnetometric studies.


2017 ◽  
Vol 80 (1) ◽  
Author(s):  
Mohamad Khairil Radzali ◽  
Akmal Hayat Abdul Karim ◽  
Syahida Ahmad ◽  
Wan Zuhainis Saad

This study was undertaken to investigate the antibacterial properties and the mode of actions of crude extract of Aspergillus fumigatus SSH01. Antibacterial properties was observed against Gram-positive pathogens and showed inhibition against Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 6538, methicillin-resistant S. aureus S547 (MRSA) and Listeria monocytogenes L10 with minimum inhibitory concentration (MIC, 0.097- 12.5 mg/ml) and minimum bactericidal concentration (MBC, 0.195 – 25 mg/ml). No surviving cells were detected after 15 h of treatment with the 2MIC of extracts for time-kill assay. Leakage of cellular contents of the treated test pathogens were identified and increased as the concentrations of the extracts increased. The study of morphological surface has shown the bacterial membrane was disrupted and caused loss of viability. This implies the antibacterial effects of A. fumigatus SSH01 extract may serve as the potential antibiotic. 


2018 ◽  
Vol 16 (2) ◽  
pp. 144 ◽  
Author(s):  
Retno Ariadi Lusiana ◽  
Dwi Siswanta ◽  
Mudasir Mudasir

Preparation of membrane using crosslinking reaction between chitosan and citric acid showed that functional group modification increased the number of active carrier groups which lead to better transport capacity of the membrane. In addition, the substitution of the carboxyl group increased creatinine permeation of chitosan membrane. The transport capacity of citric acid crosslinked chitosan membrane for creatinine was found to be 6.3 mg/L. The presence of cyanocobalamin slightly hindered the transport of creatinine although compounds did not able to pass through citric acid crosslinked chitosan/poly(vinyl alcohol) blend membrane, as compounds no found in the acceptor phase.


Sign in / Sign up

Export Citation Format

Share Document