Microgels Derived from Different Forms of Carrageenans, Kappa, Iota, and Lambda for Biomedical Applications

MRS Advances ◽  
2017 ◽  
Vol 2 (47) ◽  
pp. 2521-2527 ◽  
Author(s):  
Nurettin Sahiner ◽  
Selin Sagbas ◽  
Selahattin Yılmaz
Keyword(s):  
Biomedical Applications ◽  
Blood Clotting ◽  
Gram Negative Bacteria ◽  
Microemulsion Polymerization ◽  
Natural Polymers ◽  
Necrotic Cell ◽  
L929 Fibroblast ◽  
Model Drug ◽  
Positively Charged

ABSTRACTKappa (k-), iota (ɩ-), and lambda (λ-) Carrageenan (Car) microparticles were synthesized by crosslinking corresponding natural polymers with divinyl sulfone (DVS) via microemulsion polymerization/crosslinking methods for potential biomedical applications. Negatively charged e.g., -44 mV of Car particles were modified with diethylenetriamine (DETA) to generate positively charged modified (M-) ᴋ-Car particles with +23 mV zeta potential values. Cationic M-Car-DETA particles were found to be effectively antimicrobial material against gram negative bacteria, and some fungi species. Moreover, upon protonation of M-Car-DETA particles with HCl the effectiveness against all types of microorganisms are significantly increased. All types of Car based particles can be applicable for blood contacting material as low hemolysis ratio, 2.56% and high blood clotting capability, 86% were obtained. Furthermore, Car based particles found biocompatible against L929 fibroblast cells, and can induce necrotic cell death at 12.5 μg/mL concentration against DLD-1 colon cancer cells. M-ᴋ-Car-DETA particles were also demonstrated to be useful rending long term and linear drug release profiles using Rosmarinic Acid (RA) as a model drug.

scholarly journals Polyelectrolyte Complexes of Natural Polymers and Their Biomedical Applications

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 672 ◽  
Author(s):  
Masayuki Ishihara ◽  
Satoko Kishimoto ◽  
Shingo Nakamura ◽  
Yoko Sato ◽  
Hidemi Hattori
Keyword(s):  
Biomedical Applications ◽  
Electrostatic Interactions ◽  
Biological Activities ◽  
Wound Dressings ◽  
Natural Polymers ◽  
Tissue Adhesives ◽  
Chitosan Hydrogel ◽  
Polyelectrolyte Complexes ◽  
Micro Particles ◽  
Positively Charged

Polyelectrolyte complexes (PECs), composed of natural and biodegradable polymers, (such as positively charged chitosan or protamine and negatively charged glycosaminoglycans (GAGs)) have attracted attention as hydrogels, films, hydrocolloids, and nano-/micro-particles (N/MPs) for biomedical applications. This is due to their biocompatibility and biological activities. These PECs have been used as drug and cell delivery carriers, hemostats, wound dressings, tissue adhesives, and scaffolds for tissue engineering. In addition to their comprehensive review, this review describes our original studies and provides an overview of the characteristics of chitosan-based hydrogel, including photo-cross-linkable chitosan hydrogel and hydrocolloidal PECs, as well as molecular-weight heparin (LH)/positively charged protamine (P) N/MPs. These are generated by electrostatic interactions between negatively charged LH and positively charged P together with their potential biomedical applications.

Biomedical Applications of Natural Polymers for Drug Delivery

2014 ◽  
Vol 18 (2) ◽  
pp. 152-164 ◽  
Author(s):  
Mariana Chifiriuc ◽  
Alexandru Grumezescu ◽  
Valentina Grumezescu ◽  
Eugenia Bezirtzoglou ◽  
Veronica Lazar ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Biomedical Applications ◽  
Natural Polymers

scholarly journals Poly(Vinylamine) Derived N-Doped C-Dots with Antimicrobial and Antibiofilm Activities

2021 ◽  
Vol 7 (2) ◽  
pp. 40
Author(s):  
Semiha Duygu Sutekin ◽  
Mehtap Sahiner ◽  
Selin Sagbas Suner ◽  
Sahin Demirci ◽  
Olgun Güven ◽  
...  
Keyword(s):  
Blood Clotting ◽  
Minimum Bactericidal Concentration ◽  
Blood Compatibility ◽  
Weight Ratio ◽  
Gram Negative Bacteria ◽  
Biofilm Inhibition ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

Nitrogen-doped carbon dots (N-doped C-dots) was synthesized by using poly(vinyl amine) (PVAm) as a nitrogen source and citric acid (CA) as a carbon source via the hydrothermal method. Various weight ratios of CA and PVAm (CA:PVAm) were used to synthesize N-doped C-dots. The N-doped C-dots revealed emission at 440 nm with excitation at 360 nm and were found to increase the fluorescence intensity with an increase in the amount of PVAm. The blood compatibility studies revealed no significant hemolysis for N-doped C-dots that were prepared at different ratios of CA:PVAm for up to 500 μg/mL concentration with the hemolysis ratio of 1.96% and the minimum blood clotting index of 88.9%. N-doped C-dots were found to be more effective against Gram-positive bacteria than Gram-negative bacteria, with the highest potency on Bacillus subtilis (B. subtilis). The increase in the weight ratio of PVAm in feed during C-dots preparation from 1 to 3 leads to a decrease of the minimum bactericidal concentration (MBC) value from 6.25 to 0.75 mg/mL for B. subtilis. Antibiofilm ability of N-doped C-dots prepared by 1:3 ratio of CA:PVAm was found to reduce %biofilm inhibition and eradication- by more than half, at 0.78 mg/mL for E. coli and B. subtilis generated biofilms and almost destroyed at 25 mg/mL concentrations.

scholarly journals Topographical and Biomechanical Guidance of Electrospun Fibers for Biomedical Applications

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2896
Author(s):  
Sara Ferraris ◽  
Silvia Spriano ◽  
Alessandro Calogero Scalia ◽  
Andrea Cochis ◽  
Lia Rimondini ◽  
...  
Keyword(s):  
Surface Modification ◽  
Biomedical Applications ◽  
Biomedical Application ◽  
Electrospun Fibers ◽  
Natural Polymers ◽  
Polymeric Fibers ◽  
Biological Phenomena ◽  
Proper Design ◽  
Synthetic And Natural Polymers ◽  
Selection Of

Electrospinning is gaining increasing interest in the biomedical field as an eco-friendly and economic technique for production of random and oriented polymeric fibers. The aim of this review was to give an overview of electrospinning potentialities in the production of fibers for biomedical applications with a focus on the possibility to combine biomechanical and topographical stimuli. In fact, selection of the polymer and the eventual surface modification of the fibers allow selection of the proper chemical/biological signal to be administered to the cells. Moreover, a proper design of fiber orientation, dimension, and topography can give the opportunity to drive cell growth also from a spatial standpoint. At this purpose, the review contains a first introduction on potentialities of electrospinning for the obtainment of random and oriented fibers both with synthetic and natural polymers. The biological phenomena which can be guided and promoted by fibers composition and topography are in depth investigated and discussed in the second section of the paper. Finally, the recent strategies developed in the scientific community for the realization of electrospun fibers and for their surface modification for biomedical application are presented and discussed in the last section.

Sorption Mechanism of Carbon-14 by Hardened Cement Paste

1995 ◽  
Vol 412 ◽  
Author(s):  
K. Noshita ◽  
T. Nishi ◽  
M. Matsuda ◽  
T. Izumida
Keyword(s):  
Electrostatic Force ◽  
Cementitious Materials ◽  
Hardened Cement ◽  
Sorption Mechanism ◽  
Carbon 14 ◽  
Adsorption Sites ◽  
Radioactive Waste Repositories ◽  
Waste Repositories ◽  
Positively Charged

AbstractCarbon-14 sorption by cementitious materials should be enhanced to ensure the long term safety of radioactive waste repositories. The sorption mechanism of inorganic C- 14 (CO32- was investigated using batch sorption experiments and zeta potential measurements. The results suggested that C-14 was adsorbed onto the cement surface by an electrostatic force, due to the reaction between SiO2 and CaO contained in the cementitious composition. That is, SiO2 was originally negatively charged (SiO-) in cement, but became positively charged through the interaction of Ca2+. These positive sites on the SiO2 surface adsorbed inorganic C-14. Ordinary Portland cement (OPC) did not contain enough SiO2 compared with its CaO content to produce sufficient numbers of C-14 adsorption sites. The C-14 distribution coefficient (Kd) was increased from 2,000 to 7,000 mL/g by adding SiO2 to OPC.

Low prevalence of colonization with multidrug-resistant gram-negative bacteria in long-term care facilities in Graz, Austria

2018 ◽  
Vol 46 (1) ◽  
pp. 76-80 ◽  
Author(s):  
Eva Leitner ◽  
Elisabeth Zechner ◽  
Elisabeth Ullrich ◽  
Gernot Zarfel ◽  
Josefa Luxner ◽  
...  
Keyword(s):  
Long Term Care ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Term Care ◽  
Gram Negative ◽  
Care Facilities ◽  
Low Prevalence

scholarly journals The kfrA gene is the first in a tricistronic operon required for survival of IncP-1 plasmid R751

Microbiology ◽  
2006 ◽  
Vol 152 (6) ◽  
pp. 1621-1637 ◽  
Author(s):  
Malgorzata Adamczyk ◽  
Patrycja Dolowy ◽  
Michal Jonczyk ◽  
Christopher M. Thomas ◽  
Grazyna Jagura-Burdzy
Keyword(s):  
Coiled Coil ◽  
Broad Host Range ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Wild Type ◽  
C Terminus ◽  
Low Copy Number ◽  
And Control ◽  
Broad Host Range Plasmids

The kfrA gene of the IncP-1 broad-host-range plasmids is the best-studied member of a growing gene family that shows strong linkage to the minimal replicon of many low-copy-number plasmids. KfrA is a DNA binding protein with a long, alpha-helical, coiled-coil tail. Studying IncP-1β plasmid R751, evidence is presented that kfrA and its downstream genes upf54.8 and upf54.4 were organized in a tricistronic operon (renamed here kfrA kfrB kfrC), expressed from autoregulated kfrAp, that was also repressed by KorA and KorB. KfrA, KfrB and KfrC interacted and may have formed a multi-protein complex. Inactivation of either kfrA or kfrB in R751 resulted in long-term accumulation of plasmid-negative bacteria, whereas wild-type R751 itself persisted without selection. Immunofluorescence studies showed that KfrAR751 formed plasmid-associated foci, and deletion of the C terminus of KfrA caused plasmid R751ΔC 2 kfrA foci to disperse and mislocalize. Thus, the KfrABC complex may be an important component in the organization and control of the plasmid clusters that seem to form the segregating unit in bacterial cells. The studied operon is therefore part of the set of functions needed for R751 to function as an efficient vehicle for maintenance and spread of genes in Gram-negative bacteria.

scholarly journals Long-term durability antibacterial microcapsules with plant-derived Chinese nutgall and their applications in wound dressing

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 268-276 ◽  
Author(s):  
Wen Xue ◽  
Mengxing Zhang ◽  
Fan Zhao ◽  
Fujun Wang ◽  
Jing Gao ◽  
...  
Keyword(s):  
Wound Dressing ◽  
Antibacterial Agents ◽  
Antibacterial Efficacy ◽  
Inhibition Rate ◽  
Natural Polymers ◽  
E Coli ◽  
Significant Burden ◽  
Inhibition Zones ◽  
Integrated Performance

AbstractWound infection is a significant burden on public health. Most present antibacterial agents are typically toxic and devoid of long-term durability. We reported an antimicrobial microcapsule with Chinese nutgall (CN) encapsulated, which was a plant-derived extraction. It is biocompatible and has been used in traditional medicine systems. Sodium alginate (SA) and chitosan worked as shells. The promise of the design is to adopt biocompatible natural polymers and electrostatic attractive chitosan and SA form stable shells to keep long-term release of CN. The results exhibited microcapsules with integrated performance of biocompatibility, long-term durability (inhibition rate of 98.99% against S. aureus after 12 h and 100% after 12 h, 99.61% against E. coli after 6 h and 100% after 12 h), high antibacterial efficacy (with S. aureus inhibition zones of 7.67 mm and E. coli inhibition zones of 5.27 mm) and ease of storage (-20°C for more than 60 h). Their successful fabrication may provide new insights into application of traditional cotton gauze in a sustainable and multifunctional form.

scholarly journals A Novel Antibacterial Titanium Modification with a Sustained Release of Pac-525

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3306
Author(s):  
Yuzhu He ◽  
Yuanyuan Li ◽  
Enjun Zuo ◽  
Songling Chai ◽  
Xiang Ren ◽  
...  
Keyword(s):  
Sustained Release ◽  
Titanium Surface ◽  
Pure Titanium ◽  
Gram Negative Bacteria ◽  
Biomimetic Mineralization ◽  
Flat Rate ◽  
Bioactive Coating ◽  
Gram Positive Bacteria ◽  
Release Assay

For the benefit of antibacterial Ti on orthopedic and dental implants, a bioactive coating (Pac@PLGA MS/HA coated Ti) was deposited on the surface of pure titanium (Ti), which included two layers: an acid–alkali heat pretreated biomimetic mineralization layer and an electrosprayed Poly (D,L-lactide-co- glycolic acid) (PLGA) microsphere layer as a sustained-release system. Hydroxyapatite (HA) in mineralization layer was primarily prepared on the Ti followed by the antibacterial coating of Pac-525 loaded by PLGA microspheres. After observing the antimicrobial peptides distributed uniformly on the titanium surface, the release assay showed that the release of Pac-525 from Pac@PLGA MS/HA coated Ti provided a large initial burst followed by a slow release at a flat rate. Pac@PLGA MS/HA coated Ti exhibited a strong cytotoxicity to both Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus). In addition, Pac@PLGA MS/HA coated Ti did not affect the growth and adhesion of the osteoblast-like cell line, MC3T3-E1. These data suggested that a bionic mineralized composite coating with long-term antimicrobial activity was successfully prepared.

Aktivitas Antibakteri dari Ekstrak Etanol Ganoderma sp. Asal Pulau Lombok

2020 ◽  
Vol 6 (1) ◽  
pp. 22
Author(s):  
Adelina Oktaviani ◽  
Aida Muspiah ◽  
Faturrahman Faturrahman
Keyword(s):  
Antibacterial Activity ◽  
Inhibitory Activity ◽  
Large Diameter ◽  
Ethanolic Extract ◽  
Ethanol Extract ◽  
Positive Control ◽  
Negative Control ◽  
Gram Negative Bacteria ◽  
Activity Test

The use of antibiotics that are not according to the rules and antibiotics in the long term can cause resistance to bacteria. This study aims to determine the presence of antibacterial activity and the effect of increasing the concentration of ethanol extract of Ganoderma sp. against several test bacteria. Extract from Ganoderma sp. obtained by maceration method using ethanol 95% solvent. The extract concentrations used were 20%, 40%, 60% and 80%. This research was conducted using the wells method with ciprofloxacin as a positive control and 50% DMSO as a negative control. The parameter measured is the large diameter of the inhibition formed around the well. The results of the antibacterial activity test of ethanol extract Ganoderma sp. has greater inhibitory activity against gram-negative bacteria. The inhibitory activity of ethanolic extract of Ganoderma sp. on the growth of test bacteria increased with increasing concentration of the extract

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