School of Chemistry - Research Publications
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ItemTransforming the Chemical Structure and Bio-Nano Activity of Doxorubicin by Ultrasound for Selective Killing of Cancer Cells(WILEY-V C H VERLAG GMBH, 2022-02-18)Reconfiguring the structure and selectivity of existing chemotherapeutics represents an opportunity for developing novel tumor-selective drugs. Here, as a proof-of-concept, the use of high-frequency sound waves is demonstrated to transform the nonselective anthracycline doxorubicin into a tumor selective drug molecule. The transformed drug self-aggregates in water to form ≈200 nm nanodrugs without requiring organic solvents, chemical agents, or surfactants. The nanodrugs preferentially interact with lipid rafts in the mitochondria of cancer cells. The mitochondrial localization of the nanodrugs plays a key role in inducing reactive oxygen species mediated selective death of breast cancer, colorectal carcinoma, ovarian carcinoma, and drug-resistant cell lines. Only marginal cytotoxicity (80-100% cell viability) toward fibroblasts and cardiomyocytes is observed, even after administration of high doses of the nanodrug (25-40 µg mL-1 ). Penetration, cytotoxicity, and selectivity of the nanodrugs in tumor-mimicking tissues are validated by using a 3D coculture of cancer and healthy cells and 3D cell-collagen constructs in a perfusion bioreactor. The nanodrugs exhibit tropism for lung and limited accumulation in the liver and spleen, as suggested by in vivo biodistribution studies. The results highlight the potential of this approach to transform the structure and bioactivity of anticancer drugs and antibiotics bearing sono-active moieties.
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ItemSono-Fenton Chemistry Converts Phenol and Phenyl Derivatives into Polyphenols for Engineering Surface Coatings(WILEY-V C H VERLAG GMBH, 2021-08-25)We report a sono-Fenton strategy to mediate the supramolecular assembly of metal-phenolic networks (MPNs) as substrate-independent coatings using phenol and phenyl derivatives as building blocks. The assembly process is initiated from the generation of hydroxyl radicals (. OH) using high-frequency ultrasound (412 kHz), while the metal ions synergistically participate in the production of additional . OH for hydroxylation/phenolation of phenol and phenyl derivatives via the Fenton reaction and also coordinate with the phenolic compounds for film formation. The coating strategy is applicable to various phenol and phenyl derivatives and different metal ions including FeII , FeIII , CuII , and CoII . In addition, the sono-Fenton strategy allows real-time control over the assembly process by turning the high-frequency ultrasound on or off. The properties of the building blocks are maintained in the formed films. This work provides an environmentally friendly and controllable method to expand the application of phenolic coatings for surface engineering.
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ItemSono‐Fenton Chemistry Converts Phenol and Phenyl Derivatives into Polyphenols for Engineering Surface Coatings(Wiley, 2021-09-20)We report a sono-Fenton strategy to mediate the supramolecular assembly of metal–phenolic networks (MPNs) as substrate-independent coatings using phenol and phenyl derivatives as building blocks. The assembly process is initiated from the generation of hydroxyl radicals (.OH) using high-frequency ultrasound (412 kHz), while the metal ions synergistically participate in the production of additional .OH for hydroxylation/phenolation of phenol and phenyl derivatives via the Fenton reaction and also coordinate with the phenolic compounds for film formation. The coating strategy is applicable to various phenol and phenyl derivatives and different metal ions including FeII, FeIII, CuII, and CoII. In addition, the sono-Fenton strategy allows real-time control over the assembly process by turning the high-frequency ultrasound on or off. The properties of the building blocks are maintained in the formed films. This work provides an environmentally friendly and controllable method to expand the application of phenolic coatings for surface engineering.
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ItemInfluence of Poly(ethylene glycol) Molecular Architecture on Particle Assembly and Ex Vivo Particle-Immune Cell Interactions in Human Blood(AMER CHEMICAL SOC, 2021-05-19)Poly(ethylene glycol) (PEG) is widely used in particle assembly to impart biocompatibility and stealth-like properties in vivo for diverse biomedical applications. Previous studies have examined the effect of PEG molecular weight and PEG coating density on the biological fate of various particles; however, there are few studies that detail the fundamental role of PEG molecular architecture in particle engineering and bio-nano interactions. Herein, we engineered PEG particles using a mesoporous silica (MS) templating method and investigated how the PEG building block architecture impacted the physicochemical properties (e.g., surface chemistry and mechanical characteristics) of the PEG particles and subsequently modulated particle-immune cell interactions in human blood. Varying the PEG architecture from 3-arm to 4-arm, 6-arm, and 8-arm generated PEG particles with a denser, stiffer structure, with increasing elastic modulus from 1.5 to 14.9 kPa, inducing an increasing level of immune cell association (from 15% for 3-arm to 45% for 8-arm) with monocytes. In contrast, the precursor PEG particles with the template intact (MS@PEG) were stiffer and generally displayed higher levels of immune cell association but showed the opposite trend-immune cell association decreased with increasing PEG arm numbers. Proteomics analysis demonstrated that the biomolecular corona that formed on the PEG particles minimally influenced particle-immune cell interactions, whereas the MS@PEG particle-cell interactions correlated with the composition of the corona that was abundant in histidine-rich glycoproteins. Our work highlights the role of PEG architecture in the design of stealth PEG-based particles, thus providing a link between the synthetic nature of particles and their biological behavior in blood.
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ItemNo Preview AvailableTutorials and Articles on Best Practices(AMER CHEMICAL SOC, 2020-09-22)
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ItemNanoengineering multifunctional hybrid interfaces using adhesive glycogen nanoparticles.(Royal Society of Chemistry, 2020-06-14)Multifunctional and biodegradable nanostructured hybrid interfaces based on biopolymers are potentially useful in many applications in catalysis, bioanalytical sensing and nanomedicine. Herein, we report the engineering of multifunctional hybrid films by assembling adhesive biological nanoparticles composed of lipoate-conjugated phytoglycogen (L-PG). These nano building blocks possess adhesive properties, arising from their amphiphilic nature, and reactive functional disulfide groups. The assembly of L-PG on surfaces enabled the rapid and conformal deposition of a thin film on substrates of varying chemical composition and wettability. The L-PG films showed negligible cytotoxicity and moderate stability under different conditions but displayed enzyme-mediated degradability. In addition, metal nanoparticles were embedded into the L-PG layers to build up multilayered hybrid films. Specifically, gold and silver nanoparticle-loaded L-PG multilayered films with catalytic and surface-enhanced Raman scattering properties were prepared. Finally, we highlight the versatility of the present approach to engineer multifaceted interfaces for catalysis and sensing applications.
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ItemEngineering of Nebulized Metal-Phenolic Capsules for Controlled Pulmonary Deposition(John Wiley & Sons, 2020-03-18)Particle-based pulmonary delivery has great potential for delivering inhalable therapeutics for local or systemic applications. The design of particles with enhanced aerodynamic properties can improve lung distribution and deposition, and hence the efficacy of encapsulated inhaled drugs. This study describes the nanoengineering and nebulization of metal–phenolic capsules as pulmonary carriers of small molecule drugs and macromolecular drugs in lung cell lines, a human lung model, and mice. Tuning the aerodynamic diameter by increasing the capsule shell thickness (from ≈100 to 200 nm in increments of ≈50 nm) through repeated film deposition on a sacrificial template allows precise control of capsule deposition in a human lung model, corresponding to a shift from the alveolar region to the bronchi as aerodynamic diameter increases. The capsules are biocompatible and biodegradable, as assessed following intratracheal administration in mice, showing >85% of the capsules in the lung after 20 h, but <4% remaining after 30 days without causing lung inflammation or toxicity. Single-cell analysis from lung digests using mass cytometry shows association primarily with alveolar macrophages, with >90% of capsules remaining nonassociated with cells. The amenability to nebulization, capacity for loading, tunable aerodynamic properties, high biocompatibility, and biodegradability make these capsules attractive for controlled pulmonary delivery.
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ItemNo Preview AvailableThe Future of Layer-by-Layer Assembly: A Tribute to ACS Nano Associate Editor Helmuth Mohwald(AMER CHEMICAL SOC, 2019-06-01)Layer-by-layer (LbL) assembly is a widely used tool for engineering materials and coatings. In this Perspective, dedicated to the memory of ACS Nano associate editor Prof. Dr. Helmuth Möhwald, we discuss the developments and applications that are to come in LbL assembly, focusing on coatings, bulk materials, membranes, nanocomposites, and delivery vehicles.
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ItemModulating Targeting of Poly(ethylene glycol) Particles to Tumor Cells Using Bispecific Antibodies(WILEY, 2019-05-01)Low-fouling or "stealth" particles composed of poly(ethylene glycol) (PEG) display a striking ability to evade phagocytic cell uptake. However, functionalizing them for specific targeting is challenging. To address this challenge, stealth PEG particles prepared by a mesoporous silica templating method are functionalized with bispecific antibodies (BsAbs) to obtain PEG-BsAb particles via a one-step binding strategy for cell and tumor targeting. The dual specificity of the BsAbs-one arm binds to the PEG particles while the other targets a cell antigen (epidermal growth factor receptor, EGFR)-is exploited to modulate the number of targeting ligands per particle. Increasing the BsAb incubation concentration increases the amount of BsAb tethered to the PEG particles and enhances targeting and internalization into breast cancer cells overexpressing EGFR. The degree of BsAb functionalization does not significantly reduce the stealth properties of the PEG particles ex vivo, as assessed by their interactions with primary human blood granulocytes and monocytes. Although increasing the BsAb amount on PEG particles does not lead to the expected improvement in tumor accumulation in vivo, BsAb functionalization facilitates tumor cell uptake of PEG particles. This work highlights strategies to balance evading nonspecific clearance pathways, while improving tumor targeting and accumulation.
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ItemNo Preview AvailableContinuous assembly of polymers via solid phase reactions(ROYAL SOC CHEMISTRY, 2014-09-01)
The formation of cross-linked polymer films, with tunable thickness, proceeds directionally from the substrate surface by controlled polymerization in the solid state.