Analytical Methods for Characterization of Nanomaterial Surfaces

Jayawardena, H. Surangi N.; Liyanage, Sajani H.; Rathnayake, Kavini; Patel, Unnati; Yan, Mingdi

doi:10.1021/acs.analchem.0c05208

Cited by 60 publications

(58 citation statements)

References 132 publications

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“…Zeta potential was used to observe the stability of the nano‐assemblies. [ 22 ] As shown in Figure 3D, zeta potential of GNR@MSNP changed from day 0 to 5 from ‐23.5 ± 0.7 up to +5.0 ± 0.9 mV. This continuous change in zeta potential in media suggests that GNR@MSNP was unstable.…”

Section: Resultsmentioning

confidence: 94%

“…The zeta potential was measured after addition of each layer to monitor the change in surface charge. [ 22 ] The altered surface zeta potential is shown in Figure 2A. The zeta potential of GNRs was 28 ± 0.59 mV, this is possibly due to the presence of positively charged CTAB on the surface.…”

Section: Resultsmentioning

confidence: 99%

“…The quantitative analysis of nano‐assemblies after each step of synthesis was done through TGA. [ 22 ] The results are shown in Figure 4C and Table S3. Percentage (%) weight loss between the GNR@MSNP@BDQ and GNR@MSNP was calculated to determine the amount of BDQ loaded onto GNR@MSNP.…”

Section: Resultsmentioning

confidence: 99%

“…Porous inorganic shells are widely used in drug delivery applications due to their large pore volume, pore size and surface area. [ 18–22 ] Therefore, drug (bedaquiline, BDQ) was loaded into mesoporous silica shell containing GNR@MSNP (GNR@MSNP@BDQ). This was then encapsulated in a thermally‐sensitive liposome (TSL, GNR@MSNP@BDQ@TSL).…”

Section: Introductionmentioning

confidence: 99%

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Near‐infrared responsive targeted drug delivery system that offer chemo‐photothermal therapy against bacterial infection

et al. 2021

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To combat the rise of antibiotic resistant bacteria, it is essential to look upon other therapeutic solutions that do not solely depend upon conventional antibiotics. Here, we have designed a combinational therapeutic approach that kills bacteria with the conjunction of photothermal (PT) and antibiotic therapy. A near‐infrared (NIR) laser activated targeted drug delivery nano‐assembly delivers antibiotic as well as offer PT therapy (PTT). The synergistic application of both therapies increases the efficacy of treatment. The protected delivery of antibiotic and its release in the proximity of the bacteria surface reduces off‐target toxicity and reduce the efficacious dosage. Core of the nano‐assembly is composed of NIR active gold nanorods (GNRs) coated with a mesoporous silica nanoparticle (MSNP), which serves as a carrier for an anti‐tuberculosis drug bedaquiline (BDQ). The assembly was wrapped within a thermo‐sensitive liposome (TSL) conjugated to mycobacteria‐targeting peptide: NZX, GNR@MSNP@BDQ@TSL@NZX. NZX mediates adhesion of final nano‐assembly on mycobacteria surface. Upon NIR laser irradiation GNRs convert photo energy of the laser to localized heat, which melts TSL triggering release of BDQ. Antibacterial activity of final nano‐assembly against Mycobacterium smegmatis (Msmeg) was 20 folds more efficacious than the free drug equivalent. The final nano‐assembly could also successfully inhibit the growth of intracellular mycobacteria residing in lung cells.

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Section: Resultsmentioning

confidence: 94%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Near‐infrared responsive targeted drug delivery system that offer chemo‐photothermal therapy against bacterial infection

et al. 2021

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“…The latter has proven to be a very powerful tool to study nanocrystal surface chemistry. [40][41][42][43][44] Unfortunately, iron oxide NCs interfere with magnetic fields and cannot be studied in NMR. HfO2 NCs are thus an ideal starting point, also because their surface chemistry has already been extensively studied in nonpolar solvents using NMR spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

Mapping out the aqueous surface chemistry of metal oxide nanocrystals; carboxylate, phosphonate and catecholate ligands

Deblock

Pokratath

Buysser

et al. 2021

Preprint

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Iron oxide and hafnium oxide nanocrystals are two of the few successful examples of inorganic nanocrystals used in a clinical setting. Although crucial to their application, their aqueous surface chemistry is not fully understood. The literature contains conflicting reports regarding the optimum binding group. To alleviate these inconsistencies, we set out to systematically investigate the interaction of carboxylic acids, phosphonic acids and catechols to metal oxide nanocrystals in polar media. Using Nuclear Magnetic Resonance spectroscopy and Dynamic Light Scattering, we map out the pH-dependent binding affinity of the ligands towards hafnium oxide nanocrystals (an NMR compatible model system). Carboxylic acids easily desorb in water from the surface and only provide limited colloidal stability from pH 2 – 6. Phosphonic acids on the other hand provide colloidal stability over a broader pH range but also feature a pH-dependent desorption from the surface. They are most suited for acidic to neutral environments (pH < 8). Finally, nitrocatechol derivatives provide a tightly bound ligand shell and colloidal stability at physiological and basic pH (6-10). While dynamically bound ligands (carboxylates and phosphonates) do not provide colloidal stability in phosphate buffered saline, the tightly bound nitrocatechols provide long term stability. We thus shed light on the complex ligand binding dynamics on metal oxide nanocrystals in aqueous environments. Finally, we provide a practical colloidal stability map, guiding researchers to rationally design ligands for their desired application.

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Free‐Blockage Mesoporous Silica Nanoparticles Loaded with Cerium Oxide as ROS‐Responsive and ROS‐Scavenging Nanomedicine

Purikova

Ткаченко

Veltruská

et al. 2022

Adv Funct Materials

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Mesoporous silica nanoparticles (MSNs) with reactive oxygen species (ROS)-responsive "nanogate" as drug delivery platforms are extensively investigated for biomedical applications. However, the physical blockages used to control the cargo release are often limited by their poor sealing ability and low biocompatibility. Herein, a design of free-blockage MSNs with methylthiopropyl units is proposed as the ROS-responsive switch. Four synthetic routes are compared with different precursors through either co-condensation or grafting methods to achieve the methylthio-functionalized MSNs. The quantity, localization, and chemical structure of the functional units, as well as the mesoporous structure of the silica can be tuned by optimizing the synthetic pathways to obtain desired final products. The ROS-responsive methylthiopropyl groups can be oxidized to sulfoxides in response to the presence of H 2 O 2 , leading to the hydrophobic/hydrophilic conversion of the MSNs. As a proof-of-concept design, ultrasmall cerium oxide nanoparticles are encapsulated into the functionalized MSNs and released out within 10 min scavenging more than 80% of the H 2 O 2 in an ROS-rich environment. This study provides a novel design of a free-blockage ROS-controlled release system loaded with ROS-scavenging nanoparticles for the future application of targeted drug delivery systems combined with antioxidant therapy.

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Analytical Methods for Characterization of Nanomaterial Surfaces

Cited by 60 publications

References 132 publications

Near‐infrared responsive targeted drug delivery system that offer chemo‐photothermal therapy against bacterial infection

Near‐infrared responsive targeted drug delivery system that offer chemo‐photothermal therapy against bacterial infection

Mapping out the aqueous surface chemistry of metal oxide nanocrystals; carboxylate, phosphonate and catecholate ligands

Free‐Blockage Mesoporous Silica Nanoparticles Loaded with Cerium Oxide as ROS‐Responsive and ROS‐Scavenging Nanomedicine

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