Synthesis and Characterization of Self-Assembled Monolayer and Bilayer Carboxyl-Group Functionalized Magnetic Nanoparticles

Li, L.; Mak, K. Y.; Leung, Chi Wah; Chan, Kwong‐Yu; Chan, Wai Kin; Zhong, Wei; Pong, Philip W. T.

doi:10.1109/tmag.2012.2196504

Cited by 14 publications

(7 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The two events were more discernible when examining the derivative of the TGA curve (ESI Fig. S2 ), and could be a result of bilayer formation of citric acid on the MNP surface, as previously reported 44 – 46 . Here, an external layer of citric acid, hydrogen bonded to an inner layer desorbs sooner and at a lower temperature, followed by the inner layer, which is hydrogen bonded to the MNP surface and desorbs later at an elevated temperature.…”

Section: Resultssupporting

confidence: 76%

Magnetic cryogels as a shape-selective and customizable platform for hyperthermia-mediated drug delivery

Perera

Jackson

Bristow

et al. 2022

Sci Rep

View full text Add to dashboard Cite

Cryogels consisting of polyvinyl alcohol and iron (II, III) oxide magnetic nanoparticles coated with a model drug—acetaminophen, were developed as a tunable platform for thermally triggered drug release, based on shape-selective heat transfer. Two different shapes of cryogels; discs and spherical caps, were formed via adding polymer-nanoparticle-drug mixtures into 3D printed molds, followed by freeze-thawing five times. No additional chemical crosslinking agents were used for gel formation and the iron oxide nanoparticles were coated with acetaminophen using only citric acid as a hydrogen-bonding linker. The two gel shapes displayed varying levels of acetaminophen release within 42–50 °C, which are ideal temperatures for hyperthermia induced drug delivery. The amount and time of drug-release were shown to be tunable by changing the temperature of the medium and the shape of the gels, while keeping all other factors (ex. gel volume, surface area, polymer/nanoparticle concentrations and drug-loading) constant. The discs displayed higher drug release at all temperatures while being particularly effective at lower temperatures (42–46 °C), in contrast to the spherical caps, which were more effective at higher temperatures (48–50 °C). Magnetic hyperthermia-mediated thermal imaging and temperature profiling studies revealed starkly different heat transfer behavior from the two shapes of gels. The disc gels retained their structural integrity up to 51 °C, while the spherical caps were stable up to 59 °C, demonstrating shape-dependent robustness. The highly customizable physicochemical features, facile synthesis, biocompatibility and tunable drug release ability of these cryogels offer potential for their application as a low cost, safe and effective platform for hyperthermia-mediated drug delivery, for external applications such as wound care/muscle repair or internal applications such as melanoma treatment.

show abstract

Section: Resultssupporting

confidence: 76%

Magnetic cryogels as a shape-selective and customizable platform for hyperthermia-mediated drug delivery

Perera

Jackson

Bristow

et al. 2022

Sci Rep

View full text Add to dashboard Cite

show abstract

“…The SPIONs were prepared by the coprecipitation method. 44 In brief, 1.6 mmol of FeCl 2 and 3.2 mmol of FeCl 3 were dissolved in 12 mL of pure water at room temperature under a nitrogen atmosphere. The mixture was then heated to 80 °C followed by the addition of 12.8 mmol of NaOH dissolved in 10 mL of pure water.…”

Section: ■ Experimental Sectionmentioning

confidence: 55%

“…The SPIONs were prepared by the coprecipitation method . In brief, 1.6 mmol of FeCl 2 and 3.2 mmol of FeCl 3 were dissolved in 12 mL of pure water at room temperature under a nitrogen atmosphere.…”

Section: Methodsmentioning

confidence: 99%

Enhancing the Sensitivity of Lateral Flow Immunoassay by Magnetic Enrichment Using Multifunctional Nanocomposite Probes

Takahashi

et al. 2021

Langmuir

View full text Add to dashboard Cite

For lateral flow immunoassay (LFIA), it is an important challenge to enhance the detection sensitivity to the same level as polymerase chain reaction or enzyme-linked immunosorbent assay to make LFIA pervasive in the field of on-site environmental analysis. We recently demonstrated that the LFIA sensitivity is dramatically enhanced by using Pt-nanoparticle−latex nanocomposite beads (Pt-P2VPs) as probes for the detection of the influenza A (H1N1) antigen compared with using conventional Au colloids as probes. Here, to further enhance the LFIA sensitivity using Pt-P2VPs, superparamagnetic iron oxide nanoparticles (SPIONs) were chemically conjugated to Pt-P2VPs (Pt-P2VP@SPION) to give them magnetic separation capability (enrichment and/or purification). To investigate the effect of magnetic enrichment on the LFIA sensitivity in a sandwich format, the C-reactive protein (CRP) was chosen as a model analyte and anti-CRP antibody (CRPAb)-conjugated Pt-P2VP@SPION (Pt-P2VP@SPION-CRPAb) beads were used as probes. The visual limit of detection (LOD) of LFIA was successfully lowered by increasing the magnetic enrichment factor φ. The minimum LOD under the present experimental conditions was 0.08 ng/mL for φ = 40, which is 26-fold lower than that of the standard Au-nanoparticle-based LFIA. In theory, the LOD can be unlimitedly decreased by just increasing φ. However, the times required for both the antigen−antibody binding reaction and magnetic separation dramatically increase with φ. We also propose solutions to overcome this drawback.

show abstract

“…The weight loss percentage was measured for each corresponding temperature and plotted for comparison, as shown in Figure 4 k. For MNPs, a single weight loss of 9.70% was observed around 573 °C which could be ascribed to the adsorbed water molecules and unreacted residues removal as well. 49 , 50 Functionalized MNPs exhibited two-weight losses. The first loss was 7.29% at 253.5 °C, which is ascribed to the breaking apart of aminopropyl groups on the surface of silica-coated MNPs.…”

Section: Resultsmentioning

confidence: 99%

Silica-Coated Magnetic Nanoparticles for Vancomycin Conjugation

et al. 2022

View full text Add to dashboard Cite

Drug resistance is a global health challenge with thousands of deaths annually caused by bacterial multidrug resistance (MDR). Efforts to develop new antibacterial molecules do not meet the mounting needs imposed by the evolution of MDR. An alternative approach to overcome this challenge is developing targeted formulations that can enhance the therapeutic efficiency and limit side effects. In this aspect, vancomycin is a potent antibacterial agent that has inherent bacterial targeting properties by binding to the D-Ala-D-Ala moiety of the bacterial peptidoglycan. However, the use of vancomycin is associated with serious side effects that limit its clinical use. Herein, we report the development of vancomycin-conjugated magnetic nanoparticles using a simple conjugation method for targeted antibacterial activity. The nanoparticles were synthesized using a multistep process that starts by coating the nanoparticles with a silica layer, followed by binding an amide linker and then binding the vancomycin glycopeptide. The developed vancomycin-conjugated magnetic nanoparticles were observed to exhibit a spherical morphology and a particle size of 16.3 ± 2.6 nm, with a silica coating thickness of 5 nm and a total coating thickness of 8 nm. The vancomycin conjugation efficiency on the nanoparticles was measured spectrophotometrically to be 25.1%. Additionally, the developed formulation retained the magnetic activity of the nanoparticles, where it showed a saturation magnetization value of 51 emu/g, compared to 60 emu/g for bare magnetic nanoparticles. The in vitro cell biocompatibility demonstrated improved safety where vancomycin-conjugated nanoparticles showed IC 50 of 183.43 μg/mL, compared to a much lower value of 54.11 μg/mL for free vancomycin. While the antibacterial studies showed a comparable activity of the developed formulation, the minimum inhibitory concentration was 25 μg/mL, compared to 20 μg/mL for free vancomycin. Accordingly, the reported formulation can be used as a platform for the targeted and efficient delivery of other drugs.

show abstract

Synthesis and Characterization of Self-Assembled Monolayer and Bilayer Carboxyl-Group Functionalized Magnetic Nanoparticles

Cited by 14 publications

References 11 publications

Magnetic cryogels as a shape-selective and customizable platform for hyperthermia-mediated drug delivery

Magnetic cryogels as a shape-selective and customizable platform for hyperthermia-mediated drug delivery

Enhancing the Sensitivity of Lateral Flow Immunoassay by Magnetic Enrichment Using Multifunctional Nanocomposite Probes

Silica-Coated Magnetic Nanoparticles for Vancomycin Conjugation

Contact Info

Product

Resources

About