Search

Your search keyword '"Wong VK"' showing total 3 results
Start Over Author "Wong VK" Publisher sage publications
3 results on '"Wong VK"'

1. Dynamics of a piezoelectric energy harvester in a simulated rain environment

Author

Wong, VK, Ho, JH, Yap, EH, and Chai, AB

Subjects
0913 Mechanical Engineering
Abstract

Rain impact energy harvesting has proven to be a feasible and potent source of alternative energy. This paper presents the development of a dynamical model for rain impact energy harvester using a piezoelectric beam in simulated rain environment. Most of the conducted works in literature were based on single droplet impact with fixed height and drop position. The main contribution of this paper is to extend the single droplet impact dynamical model by incorporating random drop sizes and drop positions. In this work, a rain simulator is used to generate artificial rain of different rain rates. Following our previous works, the water accumulation on the piezoelectric beam is modeled using added mass coefficient, and impact coefficient is integrated into the dynamical model to describe the post-impact dynamics of the droplet impact. The stochastic nature of the artificial rain is described using rain rate and drop size distribution. Two random number generators are integrated into the model, which are lognormally and uniformly distributed, to generate random numbers for droplet diameter and drop position respectively. The accuracy of the theoretical model is validated experimentally by considering four different rain rates.

Published
2018

2. Polypeptide-Based Gold Nanoshells for Photothermal Therapy.

Author

Mayle KM, Dern KR, Wong VK, Sung S, Ding K, Rodriguez AR, Taylor Z, Zhou ZH, Grundfest WS, Deming TJ, and Kamei DT

Subjects
Cell Line, Tumor, Convection, Humans, Infrared Rays, Low-Level Light Therapy, Male, Models, Biological, Models, Theoretical, Prostatic Neoplasms therapy, Surface Plasmon Resonance, Gold metabolism, Hyperthermia, Induced methods, Molecular Targeted Therapy methods, Nanoshells chemistry, Peptides metabolism, Phototherapy methods
Abstract

Targeted killing of cancer cells by engineered nanoparticles holds great promise for noninvasive photothermal therapy applications. We present the design and generation of a novel class of gold nanoshells with cores composed of self-assembled block copolypeptide vesicles with photothermal properties. Specifically, poly(L-lysine) 60 - block-poly(L-leucine) 20 (K 60 L 20 ) block copolypeptide vesicles coated with a thin layer of gold demonstrate enhanced absorption of light due to surface plasmon resonance (SPR) in the near-infrared range. We show that the polypeptide-based K 60 L 20 gold nanoshells have low toxicity in the absence of laser exposure, significant heat generation upon exposure to near-infrared light, and, as a result, localized cytotoxicity within the region of laser irradiation in vitro. To gain a better understanding of our gold nanoshells in the context of photothermal therapy, we developed a comprehensive mathematical model for heat transfer and experimentally validated this model by predicting the temperature as a function of time and position in our experimental setup. This model can be used to predict which parameters of our gold nanoshells can be manipulated to improve heat generation for tumor destruction. To our knowledge, our results represent the first ever use of block copolypeptide vesicles as the core material of gold nanoshells.

Published
2017
Full Text
View/download PDF

3. Engineering A11 Minibody-Conjugated, Polypeptide-Based Gold Nanoshells for Prostate Stem Cell Antigen (PSCA)-Targeted Photothermal Therapy.

Author

Mayle KM, Dern KR, Wong VK, Chen KY, Sung S, Ding K, Rodriguez AR, Knowles S, Taylor Z, Zhou ZH, Grundfest WS, Wu AM, Deming TJ, and Kamei DT

Subjects
Cell Line, Tumor, Cell Survival drug effects, Convection, GPI-Linked Proteins metabolism, Humans, Infrared Rays, Low-Level Light Therapy, Male, Models, Biological, Models, Theoretical, Prostatic Neoplasms therapy, Surface Plasmon Resonance, Antigens, Neoplasm metabolism, Gold metabolism, Hyperthermia, Induced methods, Immunoglobulins metabolism, Molecular Targeted Therapy methods, Nanoshells chemistry, Neoplasm Proteins metabolism, Phototherapy methods
Abstract

Currently, there is no curative treatment for advanced metastatic prostate cancer, and options, such as chemotherapy, are often nonspecific, harming healthy cells and resulting in severe side effects. Attaching targeting ligands to agents used in anticancer therapies has been shown to improve efficacy and reduce nonspecific toxicity. Furthermore, the use of triggered therapies can enable spatial and temporal control over the treatment. Here, we combined an engineered prostate cancer-specific targeting ligand, the A11 minibody, with a novel photothermal therapy agent, polypeptide-based gold nanoshells, which generate heat in response to near-infrared light. We show that the A11 minibody strongly binds to the prostate stem cell antigen that is overexpressed on the surface of metastatic prostate cancer cells. Compared to nonconjugated gold nanoshells, our A11 minibody-conjugated gold nanoshell exhibited significant laser-induced, localized killing of prostate cancer cells in vitro. In addition, we improved upon a comprehensive heat transfer mathematical model that was previously developed by our laboratory. By relaxing some of the assumptions of our earlier model, we were able to generate more accurate predictions for this particular study. Our experimental and theoretical results demonstrate the potential of our novel minibody-conjugated gold nanoshells for metastatic prostate cancer therapy.

Published
2017
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results