@article{hunter2024covalent,

title = {Covalent Capture of Nanoparticle-Stabilized Oil Droplets via Acetal Chemistry Using a Hydrophilic Polymer Brush},

author = {Saul J Hunter and Evelin Csányi and Joshua JS Tyler and Mark A Newell and Matthew AH Farmer and Camery Ma and George Sanderson and Graham J Leggett and Edwin C Johnson and Steven P Armes},

url = {https://pubs.acs.org/doi/full/10.1021/acs.langmuir.4c03897},

doi = {https://doi.org/10.1021/acs.langmuir.4c03897},

year  = {2024},

date = {2024-12-06},

urldate = {2024-01-01},

journal = {Langmuir},

publisher = {ACS Publications},

abstract = {We report the capture of nanosized oil droplets using a hydrophilic aldehyde-functional polymer brush. The brush was obtained via aqueous ARGET ATRP of a cis-diol-functional methacrylic monomer from a planar silicon wafer. This precursor was then selectively oxidized using an aqueous solution of NaIO4 to introduce aldehyde groups. The oil droplets were prepared by using excess sterically stabilized diblock copolymer nanoparticles to prepare a relatively coarse squalane-in-water Pickering emulsion (mean droplet diameter = 20 μm). This precursor was then further processed via high-pressure microfluidization to produce ∼200 nm squalane droplets. We demonstrate that adsorption of these nanosized oil droplets involves acetal bond formation between the cis-diol groups located on the steric stabilizer chains and the aldehyde groups on the brush. This interaction occurs under relatively mild conditions and can be tuned by adjusting the solution pH. Hence this is a useful model system for understanding oil droplet interactions with soft surfaces.},

keywords = {Adsorption, lipids, Liquids, Nanoemulsions, nanoparticles, openQCM NEXT, QCM, QCM-D, Quartz Crystal Microbalance},

pubstate = {published},

tppubtype = {article}

}

@article{hunter2023mucoadhesive,

title = {Mucoadhesive Pickering Nanoemulsions via Dynamic Covalent Chemistry},

author = {Saul J Hunter and Mahmoud H Abu Elella and Edwin C Johnson and Laura Taramova and Emma E Brotherton and Steven P Armes and Vitaliy V Khutoryanskiy and Mark J Smallridge},

url = {https://www.sciencedirect.com/science/article/pii/S0021979723014200},

doi = {https://doi.org/10.1016/j.jcis.2023.07.162},

year  = {2023},

date = {2023-07-27},

urldate = {2023-07-27},

journal = {Journal of Colloid and Interface Science},

publisher = {Elsevier},

abstract = {Hypothesis. Submicron oil droplets stabilized using aldehyde-functionalized nanoparticles should adhere to the primary amine groups present at the surface of sheep nasal mucosal tissue via Schiff base chemistry. Experiments. Well-defined sterically-stabilized diblock copolymer nanoparticles of 20 nm diameter were prepared in the form of concentrated aqueous dispersions via reversible addition-fragmentation chain transfer (RAFT) aqueous emulsion polymerization of 2,2,2-trifluoroethyl methacrylate (TFEMA) using a water-soluble methacrylic precursor bearing cis-diol groups. Some of these hydroxyl-functional nanoparticles were then selectively oxidized using an aqueous solution of sodium periodate to form a second batch of nanoparticles bearing pendent aldehyde groups within the steric stabilizer chains. Subjecting either hydroxyl- or aldehyde-functional nanoparticles to high-shear homogenization with a model oil (squalane) produced oil-in-water Pickering macroemulsions of 20-30 µm diameter. High-pressure microfluidization of such macroemulsions led to formation of the corresponding Pickering nanoemulsions with a mean droplet diameter of around 200 nm. Quartz crystal microbalance (QCM) experiments were used to examine adsorption of both nanoparticles and oil droplets onto a model planar substrate bearing primary amine groups, while a fluorescence microscopy-based mucoadhesion assay was developed to assess adsorption of the oil droplets onto sheep nasal mucosal tissue. Findings. Squalane droplets coated with aldehyde-functional nanoparticles adhered significantly more strongly to sheep nasal mucosal tissue than those coated with the corresponding hydroxyl-functional nanoparticles. This difference was attributed to the formation of surface imine bonds via Schiff base chemistry and was also observed for the two types of nanoparticles alone in QCM studies. Preliminary biocompatibility studies using planaria indicated only mild toxicity for these new mucoadhesive Pickering nanoemulsions, suggesting potential applications for the localized delivery of hydrophobic drugs.},

keywords = {Aldehyde-Functionalized Nanoparticles, Mucoadhesive Drug, Nanoemulsions, openQCM NEXT, QCM-D, Quartz Crystal Microbalance},

pubstate = {published},

tppubtype = {article}

}