Projects

@article{nokey,

title = {Shear Stress Targeted Delivery of Nitroglycerin to Brain Collaterals Improves Ischaemic Stroke Outcome},

author = {M. Litman and S. Azarpeykan and R. J. Hood and K. Martin and D. Pepperall and D. Omileke and O. Uzun and D. Bhatta and Y. K. Yong and A. Chan and N. Hough and S. Johnson and P. G. Bermejo and F. Miteff and C. G. Esperon and Y. Couch and A. M. Buchan and N. J. Spratt and N. Korin and D. E. Ingber and D. J. Beard},

doi = { https://doi.org/10.1002/advs.202506276},

year  = {2025},

date = {2025-08-13},

urldate = {2025-03-01},

journal = {Advanced Science},

volume = {e06276},

abstract = {In patients with ischaemic stroke, retrograde perfusion of the penumbra by the leptomeningeal collateral vessels (LMCs) is a strong predictor of clinical outcome, thus raising the possibility that enhancing LMC flow could offer a novel therapeutic approach. Here, using computational modelling we show that LMCs experience elevated fluid shear stress that is significantly higher than that in other blood vessels during ischaemic stroke in animals and humans. We take advantage of this to selectively enhance flow in LMCs using shear-activated nanoparticle aggregates carrying the vasodilator nitroglycerin (NG-NPAs) that specifically release drug in regions of vessels with high shear stress (≥100 dyne/cm2). The NG-NPAs significantly increased LMC-mediated penumbral perfusion, decreased infarct volume, and reduced neurological deficit without altering systemic blood pressure in a rat ischaemic stroke model. The NG-NPAs also did not cause known common side effects of systemic nitrate administration, such as systemic hypotension, cerebral vascular steal, cortical vein dilation, or intracranial pressure elevation. Systemic administration of free NG at the maximal tolerated dose, which was ten times higher than the dose of NG used in the NG-NPAs, did not enhance LMC perfusion and dropped blood pressure. Thus, packaging NG within shear-activated NPAs can potentially enable this widely available vasodilator to become a highly effective therapeutic for ischaemic stroke.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Mai2025,

title = {Fabrication of Microneedles by Pulsating In Situ Dried Electrostretching for Transdermal Drug Delivery},

author = {N. L. Mai, Y. K. Yong, T. A. Hoang, T. H. Vu, H Vu, V. C. Doan, D. Cai, T. X. Dinh, D. V. Dao, V. T. Dau},

doi = {https://doi.org/10.1002/smtd.202500183},

year  = {2025},

date = {2025-06-11},

urldate = {2025-05-07},

journal = {Small Methods},

abstract = {This paper introduces a novel pulsating in situ dried electrostretching (PIDES) technique for the fabrication of microneedles (MNs) for transdermal drug delivery. This method utilizes pulsed voltage to induce electrohydrodynamic forces that stretch and freeze a polymer droplet into a conical shape with a micrometer-scale tip. With the effects of solvent evaporation, the polymeric droplet is in situ stretched into a conical shape and solidified, transforming into a sharp MN, suitable for transdermal drug administration. Penetration and mechanical tests confirm that the MNs possess sufficient sharpness and strength for effective skin penetration applications. Additionally, curcumin loading and in vitro release tests with different concentrations demonstrate the MNs' ability to carry drugs and exhibit effective controlled release profiles. These findings highlight PIDES as a promising, low-cost, and simple approach for the development of painless and efficient transdermal drug delivery systems.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Mai2025b,

title = {Evaporation in electrohydrodynamic atomisation: A numerical and experimental investigation},

author = {N. L. Mai, T. H. Vu, H. Vu, C. Doan, Y. K. Yong, T. X. Dinh, D. V. Dao, V. T. Dau},

doi = {https://doi.org/10.1016/j.icheatmasstransfer.2025.109079},

year  = {2025},

date = {2025-06-01},

urldate = {2025-06-01},

journal = {International Communications in Heat and Mass Transfer},

volume = {165, Part B},

pages = {109079},

abstract = {In this paper, the influence of evaporation in electrohydrodynamic atomization (electrospray) is numerically and experimentally investigated. The simulation was performed utilizing the Taylor-Melcher's leaky-dielectric model and the d2 Law to simulate thermophysical processes in electrospray. Experiments were conducted to validate the numerical approach and to investigate the influence of evaporation on particle morphology. Results by simulations are consistent with experiments, showing agreement in both Taylor-cone captured by high-speed camera and vapour field visualized by Schlieren imaging. Experiments on different solvents suggest major impacts of interelectrode distance on the residual solvent on the collected particles. However, these impacts were less significant on particle size and morphology particularly when using solvents with medium to low volatility. Particle size is found to increase with temperature and solvent volatility, confirming the correlation reported in literature. Moreover, evaporation was determined to have limited effect on the overall shape of the Taylor-cone and spray jet, due to inherently high vapour concentration around the nozzle vicinity. These contributions will improve the understanding of evaporation process in electrospray and offer useful guidelines for optimizing the technique, particularly in situations where evaporation is a key factor controlling particle size and minimizing harmful residue.

Keywords: Numerical methods; Evaporation; Electrospray; Electrohydrodynamic atomization; Experiments; Particle morphology

},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Ruppert2025,

title = {Modulated-Illumination Intermittent-Contact Tip-Enhanced Raman Spectroscopy},

author = {M. G. Ruppert and B. S. Routley and L. R. McCourt and Y. K. Yong and A. J. Fleming},

url = {https://www.precisionmechatronicslab.com/wp-content/uploads/2025/05/Article.pdf},

doi = {https://doi.org/10.1021/acs.nanolett.4c06397},

issn = {1530-6984},

year  = {2025},

date = {2025-03-13},

urldate = {2025-03-13},

journal = {ACS Nano Letters},

volume = {25},

issue = {14},

pages = {5656-5662},

abstract = {This article presents a proof-of-concept for a new imaging method that combines tip-enhanced Raman spectroscopy with intermittent-contact atomic force microscopy to provide simultaneous nanometer-scale mechanical imaging with chemical contrast. The foremost difference from a standard tip-enhanced Raman microscope is the Raman illumination, which is modulated by the cantilever drive signal so that illumination is only active when the tip is close to the surface. This approach significantly reduces contact forces and thermal damage due to constant illumination while simultaneously reducing background Raman signals. Near-field optical and dynamic cantilever simulations highlight the effect of the imaging parameters on the tip–sample force and the evanescent field enhancement. The experimental images obtained with this new imaging method demonstrate a lateral resolution sufficient to identify single-walled carbon nanotube bundles with a full width at half-maximum of 20 nm.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}