Recent remarkable advances in the field of nanotechnology has been achieved in the last few years especially in the fabrication of sensors that have wide number of applications. Nanomaterials are the ...foundation of nanotechnology that are measured on nanoscale. Carbon nanotubes (CNTs) are tube-like materials that are made up of carbon with a diameter calculating on a nanometer scale. They are originated from graphite sheet and these graphite layers seems similar to a rolled up non-stop unbreakable hexagonal like mesh structure and the carbon molecules appears at the apexes of the hexagonal structures. Depending upon the number of carbon layers, carbon nanotubes can be single-walled carbon nanotubes (SWCNTs), double-walled carbon nanotubes (DWCNTs) and multi-walled carbon nanotubes (MWCNTs). Carbon nanotubes (CNTs) can be fabricated by three main methods i.e., chemical vapor deposition, electric arc method and laser deposition method. Carbon nanotubes exhibit various characteristic properties such as high elasticity, high thermal conductivity, low density and they are chemically more inert etc. Due to these interesting properties, carbon nanotubes have played a significant role in the field of nanotechnology, electronics, optics and other fields of materials science. Carbon nanotubes are being positively applied in drug delivery, sensing, water treatment etc. Functionalization of their surface can result in highly soluble materials, which can be further derivatized with active molecules, making them compatible with biological systems. Surface functionalization enables adsorption or attachment of various molecules or antigens, which subsequently can be targeted to the desired cell population for immune recognition or a therapeutic effect. In this review, properties of carbon nanotubes and their clinical applications such as medical diagnostics and drug delivery are being discussed. Here, antibacterial as well as antifungal activity of carbon nanotubes are also being reviewed.
•The PDA@Ag coating on α-TCP cement was prepared conveniently and efficiently.•The effect of the coating on mineralization properties of cement was investigated.•The antibacterial assay of the cement ...was performed and the mechanism was analyzed.
The ideal orthopedic material demands excellent antimicrobial properties and bioactivity after initial implantation in vivo. In this paper, a polydopamine (PDA) film was prepared by dopamine self-polymerization on α-tricalcium phosphate (α-TCP) cement, and then silver (Ag) particles were immobilized in-situ on the surface of PDA via a dipping method. The presence of PDA and Ag in the composition of modified cement was confirmed by XPS. The results showed that after the modification of PDA coating and Ag particles, the roughness and contact angle of the cement increased from 36.4 nm to 120 nm and 18.8° to 58.8°, respectively. Moreover, the mineralization capacity of modified cement was considerably enhanced, generating dense hydroxyapatite (HA) layer with a thickness of 3.04 μm. Furthermore, the modified cement was revealed to provide antibacterial rate over 99 %. It is suggested that good bioactivity and antimicrobial properties of the cement can be achieved using the promising method.
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•ZIF-8 has antibacterial properties superior to ZnO, a benchmark nanomaterial.•ZIF-8 displays variable antibacterial performance in different liquid environments.•Degradation pathways ...and by-products affect MOFs’ antibacterial performance.•ZIF-8 degrades more in culture media than in deionized water, and faster than ZnO.•MOFs’ aqueous stability must be fully understood for their application development.
The stability and degradation characteristics of metal–organic frameworks (MOFs) in liquid media dictate their use in biomedical engineering applications. In this study, the antibacterial property of a zinc-based MOF, zeolite imidazolate framework-8 (ZIF-8), against gram-negative Escherichia coli (E. coli) is studied in comparison with ZnO, a widely-used antimicrobial agent. Superior antibacterial property of ZIF-8 was demonstrated and the reason was elucidated by new insights on the stability of ZIF-8 in bacterial culture media. Contrary to the widely held notion that ZIF-8 is stable in aqueous media, inductively coupled plasma-optical emission spectrometry and UV–Vis adsorption spectroscopy revealed the release of zinc ions and 2-methyilimidazolate molecules in the culture media. Electron microscopy and X-ray diffractometry revealed that the degradation of ZIF-8 is enhanced by the reaction of released zinc ions with phosphate ions in phosphate-buffered saline (PBS) or with organic moieties in Luria Bertani (LB) media, resulting in stronger antibacterial properties of ZIF-8 than that of ZnO. In fact, due to the affinity of ions and organic constituents in the cell media towards the building block of ZIF-8 structure, a higher amount of ZIF-8 degrades in LB and PBS media (70–80 wt%) than in pure water (22 wt%) after 24 h of immersion. The results of the present investigation strongly advocate the importance of stability study on MOFs in developing their biomedical applications, in terms of its efficacy, biosafety and eco-safety.
Improving antibacterial performance is one of the prerequisites for the clinical application of bacterial cellulose (BC)-based dressings. In this study, a novel copper (Cu) ion loaded BC-based ...antibacterial wound dressing was prepared via codeposition of polydopamine (PDA) and copper ion. The scanning electron microscope (SEM) results showed that the copper ion/PDA coating was more uniform than the PDA coating, and the 3D nanopore structure of BC was retained in Cu
@PBC. Cu ions were immobilized by forming a chelate with PDA. The thermal stability and mechanical properties of the Cu
@PBC dressing decreased with the addition of copper ions. Cu
@PBC-2 film with a certain amount of copper sulfate used (10 nM) exhibited favorable antibacterial properties against both S. aureus and E. coli without obvious cytotoxicity. The results of the in vivo study also demonstrated that the Cu
@PBC-2 film can eliminate S. aureus infections and inflammatory response, promote collagen deposition, capillary angiogenesis, hair follicle growth and wound healing. These results suggest that the Cu
@PBC-2 film has prospective application as a wound dressing.
•Eco-friendly PAN composite was prepared by using biomass materials.•PAN composite had excellent flame retardancy and antibacterial properties.•The modification is environmentally friendly, simple ...process and easy to prepare.
To improve the fire safety of polyacrylonitrile (PAN) and expand its application area, flame retardant and antibacterial PAN composite was prepared by a simple and environmentally friendly method. First, AgNO3 and NaBH4 solutions were added to the microcrystalline cellulose (MCC) aqueous suspension to prepare MCC loaded Ag nanoparticles (Ag NPs) (MCC/Ag) by in situ reduction. Then, MCC/Ag was mixed in PAN solution to prepare MCC/Ag/PAN composite, which was then phosphorylated by phytic acid (PA) to obtain flame retardant MCC/Ag/PAN composite (FR-MCC/Ag/PAN). FR-MCC/Ag/PAN could achieve self-extinguishing with limiting oxygen index (LOI) value of 36.8 %. The thermogravimetric results showed that phosphorus-containing acids accelerated the char-forming ability of FR-MCC/Ag/PAN, and the final char residue was up to 29.76 % in air atmosphere. Thermogravimetric coupled with Fourier transform infrared spectroscopy (TG-FTIR) and scanning electron microscope (SEM) showed that FR-MCC/Ag/PAN formed an expanded and dense char layer after combustion, suppressing the release of low molecular toxic gases. Moreover, FR-MCC/Ag/PAN showed favorable inhibition of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). This work proposed a novel method for developing flame retardant and antibacterial PAN material, which broadened the application field of polyacrylonitrile.
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Diabetic wound treatment remains a major challenge due to the difficulties of eliminating bacterial biofilm and relieving wound hypoxia. To address these issues simultaneously, a ...multifunctional Dex-SA-AEMA/MnO2/PDA (DSAMP) hydrogel platform was developed with excellent biocompatibility and porous structure. The hydrogel could absorb the exudate, maintain humidity and permeate oxygen, which was prepared by encapsulating polydopamine (PDA) and manganese dioxide (MnO2) into Dex-SA-AEMA (DSA) hydrogel by UV irradiation. With the addition of PDA, the DSAMP hydrogel was proved to eliminate the biofilm after NIR photodynamic therapy (PTT, 808 nm) irradiation at 54 °C. Furthermore, in order to mitigate hypoxia wound microenvironment, MnO2 nanoparticles were added to convert the endogenous hydrogen peroxide (H2O2) into oxygen (O2, 16 mg L−1). The diabetic wound in vivo treated by DSAMP hydrogel was completely healed on 14 days. It was revealed that the DSAMP hydrogel possessed a great potential as dressing for diabetic chronic wound healing.
Most recently, silver nanoparticles due to antibacterial properties have been considered in medical science. So the aim of the study was green synthesis of silver nanoparticles using Berberis ...vulgaris leaf and root aqueous extract and its antibacterial activity. After collection, identification and extraction of Berberis vulgaris was performed production of silver nanoparticles. In the study effect of parameters such as AgNO3 concentration (0.5, 1, 3, 10 mM), aqueous extract (3, 5, 10, 15, 30 mL) and contact time (1, 2, 6, 12, 24 h) were investigated in the synthesis of nanoparticles and also the antibacterial effect of these nanoparticles was studied on Escherichia coli and Staphylococcus aureus bacteria by Disk diffusion test and Minimum Inhibitory Concentration test (MIC). According to XRD results and analysis of TEM, nanoparticles have spherical shapes and size of 30 to 70 nm. On the other hand antibacterial tests showed these nanoparticles have more antibacterial activity more than other extracts. Result showed the biosynthesis of silver nanoparticles using aqueous extract of Berberis vulgaris is a clean, inexpensive and safe method that has not been used any toxic substance and consequently does not side effects and this nanoparticles has a high antibacterial activity.
•Green Synthesis of Silver Nanoparticles Using Berberis Vulgaris Leaf and Root Aqueous Extract•Investigation of Antimicrobial Properties using Synthesis of Silver Nanoparticles•Doing Disc Diffusion Test and Minimum Inhibitory Concentration Test•Ultraviolet-visible spectroscopyto identify nanoparticles synthesized•X-ray diffraction spectroscopyto identify nanoparticles synthesized•Dynamic Light Scattering Spectroscopy for identification nanoparticles synthesis•Transmission electron microscopy spectroscopy for identification nanoparticles synthesis
Since the fire hazards of polyester-cotton blended (PTCO) fabrics and the hidden dangers of bacterial infection concerns caused by the contained cotton fiber, the design of flame retardant and ...antibacterial PTCO fabrics has received considerable attention. In this work, flame-retardant PTCO fabrics with satisfactory antibacterial properties were fabricated via a convenient and eco-friendly impregnation treatment involving guanidine phosphate (GP) and polyethylenimine (PEI). The prepared PTCO fabrics demonstrated excellent flame retardancy with a high limiting oxygen index value of 30.5 % and self-extinguishing capability, the damaged length was only 34 mm in the vertical flammability test. Furthermore, the peak heat release rate and the total heat release of coated PTCO fabrics were reduced significantly by 49 % and 38 %, respectively, indicating a substantial enhancement in fire safety. According to the analysis of the char residues and volatiles, GP presented great catalytic carbonization property, and PEI assisted the formation of the dense and stable carbon layer. The stable carbon layer effectively restricted mass and oxygen transfer between the PTCO fabrics and the environment. In addition, the introduction of PEI also produced more nonflammable gases to enhance the flame retardancy of the PTCO fabrics. Importantly, the GP/PEI coating barely deteriorate the physical and mechanical properties of the PTCO fabrics. The antibacterial rate of the GP/PEI-coated PTCO fabrics against Escherichia coli and Staphylococcus aureus was 99.99 %, similar to that of GP-coated fabrics, indicating the efficacy antibacterial properties of GP, and the addition of PEI did not compromise the antibacterial properties of GP. This work offers an efficient and simple approach to producing multifunctional PTCO fabrics with excellent flame retardancy and antibacterial properties, which are hopeful to expand the promising application of PTCO fabrics.
•Guanidine phosphate and polyethylenimine coating were constructed on polyester-cotton blend fabrics.•The coating imparts efficient flame retardancy and antibacterial properties to polyester-cotton blend fabrics•The LOI of coated fabric reached 30.5 % and the “scaffolding effect” was eliminated.•The coated fabrics exhibited flame-retardant activities in both condensed and gaseous phases during combustion.•The antibacterial rates of the coated PTCO fabrics against E. coli and S. aureus were 99.99 %.
Glucose is abundant in nature and can be found in various sources. In this study, we developed multifunctional carbon dots (CDs) with glucose and poly(ethyleneimine) (PEI), which were further ...quaternized using a facile approach. The CDs are designed to possess both anti-bacteria and gene delivery capabilities. The inherent property was characterized with TEM, NMR, FTIR and fluorescent spectroscopy. Antibacterial activity was evaluated with Broth minimum inhibitory concentration (MIC) assay on both Gram-positive and Gram-negative bacteria. The CDs showed excellent inhibitation to both bacteria. The expression of CDs condensed plasmid DNA in HEK 293T cells was investigated with luciferase expression assay. Gene transfection capability of the quaternized CDs was found to be up to 10 super(4) times efficient than naked DNA delivery.
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