scholarly journals Antimicrobial Surface Functionality of PEG Coated and AgNPs Immobilized Extracorporeal Biomaterials

2021 ◽  
Vol 12 (1) ◽  
pp. 1039-1052

Nanotechnology is a promising field for generating new medicine applications like colloidal silver to prevent nosocomial infections. In this study, the objection of the presented manuscript was to test the antimicrobial activity of PEG/silver nanoparticles (AgNPs) coated blood tubing used in hemodialysis. The modification of plastic tubing was first performed by PEG coating, which was followed by immobilization of AgNPs synthesized with a green chemical approach from the leaves of Liquidambar Orientalis Miller. The stabilization of each surface modification stage was assured by methanol fixation. The characterization of AgNPs, surface modification steps, and final tubing surface appearances was performed by spectrophotometric measurements, DLS analysis, FTIR spectrums, and SEM images. The results indicated that the surfaces of hemodialysis tubing were successfully coated with PEG/AgNPs processed sequentially. Antimicrobial activities were evaluated against pathogens (Escherichia coli, Pseudomonas aeruginosa. Klebsiella pneumonia, Staphylococcus aureus, and Candida albicans), which are commonly involved in catheter-related infections. In conclusion, a new AgNPs immobilization method to polymeric catheter surfaces after PEG layering was developed. The antimicrobial function against five nosocomial microorganisms would have potential in biomedical applications.

2019 ◽  
Vol 25 (34) ◽  
pp. 3672-3680 ◽  
Author(s):  
Nasrullah Shah ◽  
Tahir Zaman ◽  
Touseef Rehan ◽  
Salman Khan ◽  
Waliullah Khan ◽  
...  

Purpose: The purpose of the present study was to make a biocompatible agar based composite material via incorporation of appropriate additives within the agar matrix for potential applications in drug delivery and biomedical fields. Methodology: Agar based composites were prepared by the incorporation of magnetic iron oxide nano particles, graphite and sodium aluminum as additives in different proportions within the agar matrix by a simple thermophysico- mechanical method. The as prepared agar based composites were then characterized by different techniques i.e. FTIR, SEM, TGA, XRD and EDX analyses. The FTIR peaks confirmed the presence of each component in the agar composite. SEM images showed the uniform distribution of each component in the agar composite. TGA study showed the thermal stability range of different composite sheets. XRD pattern revealed the crystallinity and EDX analysis confirmed the elemental composition of the prepared composites. The prepared agar based composites were evaluated for antimicrobial activities against three pathogenic bacterial strains Escherichia coli, Staphylococcus aureus and Klebsiella pneumonia and the result indicated efficient antimicrobial activities for all composites. Conclusions: From the overall study, it was concluded that due to the non-toxic nature, thermal stability and excellent antibacterial properties, the prepared agar based composites can receive potential biomedical applications.


2012 ◽  
Vol 476-478 ◽  
pp. 457-460 ◽  
Author(s):  
Na Yin ◽  
Shi Yan Chen ◽  
Yang Ou Yang ◽  
Lian Tang ◽  
Zhe Li ◽  
...  

In this study, biomimetic synthesis of hydroxyapatite (HAp) nanocomposites based on bacterial cellulose (BC) with sodium alginate (SA) surface modification was studied. The results showed that SA treatment promoted the apatite nucleation ability of BC in SBF solution. The FE-SEM images demonstrated that HAp nanoparticles were successfully formed in the three dimensional nanofiber network of BC. FTIR spectra indicated that the obtained HAp crystals were partially substituted with carbonate, which were very similar with natural bones. It was also found that both of crystallite size and crystallinity of HAp crystals observed from XRD pattern were very low. The resultant nanocomposites consisted of nano-scale HAp crystals and SA treated BC nanofibrous have great potential application in bone tissue engineering.


Author(s):  
Shen Gong ◽  
Zhenghong Zhu ◽  
Jun Li

This work investigated and characterized the electrical conductivity of carbon nanotubes (CNT)/polymer composites. Surface modification has been applied to improve the homogeneous dispersion of MWCNTs in epoxy. After treatment, MWCNTs were mixed into low viscosity epoxy matrix at room temperature. Dispersion and structural integrity of MWCNTs before and after surface modification were examined by SEM images. The dispensability of treated MWCNTs and electrical conductivity of nanocomposites are evaluated and also compared with MWCNTs/polymer composites in literature prepared using the same commercial MWCNTs. The electrical conductivity of MWCNTs and MWCNTs/epoxy composites were evaluated by the four-point probe method. The results of electrical property will lay a foundation for establishing the relationship between electrical resistance and strain of MWCNTs/epoxy composites. The results also confirm that reducing CNT agglomerate size can greatly improve the electrical conductivity of composite and decrease the percolation threshold.


2020 ◽  
Vol 10 (4) ◽  
pp. 93-97
Author(s):  
Anil Kumar A ◽  
Raja Sheker K ◽  
Naveen B ◽  
Abhilash G ◽  
Akila CR

Seas assets that give us a variety of characteristic items to control bacterial, contagious and viral ailment and mostly utilized for malignancy chemotherapy practically from spineless creatures, for example, bryozoans, wipes, delicate corals, coelenterates, ocean fans, ocean bunnies, molluscs and echinoderms. In the previous 30 - 40 years, marine plants and creatures have been the focal point of overall endeavours to characterize the regular results of the marine condition. Numerous marine characteristic items have been effectively exceptional to the last phases of clinical preliminaries, including dolastatin-10, a group of peptides disengaged from Indian ocean rabbit, Dollabella auricularia. Ecteinascidin-743 from mangrove tunicate Ecteinascidia turbinata, Didemnins was isolated from Caribbean tunicate Trididemnum solidum and Conopeptides from cone snails (Conus sp.), and a developing number of up-and-comers have been chosen as promising leads for expanded pre-clinical appraisals. Sea anemones possess numerous tentacles containing stinging cells or cnidocytes. The stinging cells are equipped with small organelles known as nematocysts. The two species of sea anemones namely, Heteractis magnificaandStichodactyla haddoni, were collected from Mandapam coastal waters of Ramanathapuram district, Tamilnadu, India. The Nematocyst was collected and centrifuged, and the supernatant was lyophilized and stored for further analysis. The amount of protein from Heteractis Magnifica and Stichodactyla haddoni was estimated. The crude extract has shown haemolytic activity on chicken blood and goat blood. In the antibacterial activity of the sea anemone against six bacterial strains Staphylococcus aureus, Salmonella typhii, Salmonella paratyphii, Klebsiella pneumonia, Vibrio cholerae, Pseudomonas aeruginosa. Antibacterial activity of H. Magnifica and S.haddoni was measured as the radius of the zone of inhibition.


2020 ◽  
Vol 4 (1) ◽  
pp. 15
Author(s):  
Eduardo Ravelo-Nieto ◽  
Alvaro Duarte-Ruiz ◽  
Luis H. Reyes ◽  
Juan C. Cruz

Several biological barriers are generally responsible for the limited delivery of cargoes at the cellular level. Fullerenols have unique structural features and possess suitable properties for interaction with the cells. This study aimed to synthesize and characterize a fullerenol derivative with desirable characteristics (size, charge, functionality) to develop cell penetration vehicles. Fullerenol was synthesized from fullerene (C60) solubilized in toluene, followed by hydroxylation with hydrogen peroxide and tetra-n-butylammonium hydroxide (TBAH) as a phase transfer catalyst. The obtained product was purified by a Florisil chromatography column (water as the eluent), followed by dialysis (cellulose membrane dialysis tubing) and freeze-drying (yield 66%). Subsequently, a silane coupling agent was conjugated on the fullerenol surface to render free amine functional groups for further covalent functionalization with other molecules. Characterization via UV–VIS, FTIR-ATR, Raman, DLS, and SEM techniques was conducted to evaluate the composition, size, morphology, surface functionality, and structural properties. We are currently working on the conjugation of the potent cell-penetrating agents Buforin II (BUFII) and the Outer Membrane Protein A (OmpA) on the surface of the fullerenol to estimate whether cell penetration and endosome escape are improved concerning conventional polymeric vehicles and our previous developments with iron oxide nanoparticles.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 931
Author(s):  
Ioana-Codruţa Mirică ◽  
Gabriel Furtos ◽  
Ondine Lucaciu ◽  
Petru Pascuta ◽  
Mihaela Vlassa ◽  
...  

The aim of this research was to develop new electrospun membranes (EMs) based on polycaprolactone (PCL) with or without metronidazole (MET)/nano-hydroxyapatite (nHAP) content. New nHAP with a mean diameter of 34 nm in length was synthesized. X-ray diffraction (XRD) and attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR) were used for structural characterization of precursors and EMs. The highest mechanical properties (the force at maximum load, Young’s modulus and tensile strength) were found for the PCL membranes, and these properties decreased for the other samples in the following order: 95% PCL + 5% nHAP > 80% PCL + 20% MET > 75% PCL + 5% nHAP + 20% MET. The stiffness increased with the addition of 5 wt.% nHAP. The SEM images of EMs showed randomly oriented bead-free fibers that generated a porous structure with interconnected macropores. The fiber diameter showed values between 2 and 16 µm. The fiber diameter increased with the addition of nHAP filler and decreased when MET was added. New EMs with nHAP and MET could be promising materials for guided bone regeneration or tissue engineering.


2006 ◽  
Vol 514-516 ◽  
pp. 1005-1009 ◽  
Author(s):  
José V. Araújo ◽  
J.A. Lopes da Silva ◽  
Margarida M. Almeida ◽  
Maria Elisabete V. Costa

Porous chitosan/brushite composite scaffolds were prepared by a freeze-drying technique, starting from brushite suspensions in chitosan solutions. The obtained scaffolds showed a regular macroporous and interconnected structure with brushite particles uniformly distributed in the chitosan matrix. The variation of the brushite concentration affected the microstructure of the final freeze-dried scaffold, in particular, its porosity and its average pore size. The yield strengths of the composite scaffolds could also be improved by the increase of the brushite content.


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