A5034628285- Ultrasound and Hyperthermia Applications
- Photoacoustic and Ultrasonic Imaging
- Ultrasound and Cavitation Phenomena
- Rheology and Fluid Dynamics Studies
- Fluid Dynamics and Heat Transfer
- Ultrasound Imaging and Elastography
- Lattice Boltzmann Simulation Studies
- Surface Modification and Superhydrophobicity
- 3D Printing in Biomedical Research
- Electrohydrodynamics and Fluid Dynamics
- Blood properties and coagulation
- Nanoparticle-Based Drug Delivery
- Particle Dynamics in Fluid Flows
- Microfluidic and Bio-sensing Technologies
- Fluid Dynamics and Mixing
- Pickering emulsions and particle stabilization
- Electrospun Nanofibers in Biomedical Applications
- Polymer crystallization and properties
- Fluid Dynamics and Thin Films
- Bone Tissue Engineering Materials
- nanoparticles nucleation surface interactions
- Underwater Acoustics Research
- Cardiovascular and Diving-Related Complications
- Innovative Microfluidic and Catalytic Techniques Innovation
- Advanced MRI Techniques and Applications
George Washington University
2016-2025
University of Delaware
2007-2016
Johns Hopkins University
1992-2013
George Washington University Virginia Campus
2013
Indian Institute of Engineering Science and Technology, Shibpur
2013
University of Illinois Urbana-Champaign
2000-2002
Dynaflow (United States)
1996-1998
Sandia National Laboratories
1995
Four dimensional (4D) printing is an emerging technology with great capacity for fabricating complex, stimuli-responsive 3D structures, providing potential tissue and organ engineering applications. Although the 4D concept was first highlighted in 2013, extensive research has rapidly developed, along more-in-depth understanding assertions regarding definition of 4D. In this review, we begin by establishing criteria printing, followed summary state-of-the-art technological advances field....
4D printing represents one of the most advanced fabrication techniques for prospective applications in tissue engineering, biomedical devices, and soft robotics, among others. In this study, a novel multiresponsive architecture is developed through stereolithography-based printing, where universal concept stress-induced shape transformation applied to achieve reprogramming. The light-induced graded internal stress followed by subsequent solvent-induced relaxation, driving an autonomous...
Zero-thickness interface models are developed to describe the encapsulation of microbubble contrast agents. Two different rheological interface, Newtonian (viscous) and viscoelastic, with parameters such as surface tension, dilatational viscosity, elasticity presented characterize encapsulation. The applied a widely used based ultrasound agent. Attenuation passing through solution agent is measured. model for determined by matching linearized dynamics measured attenuation data. investigated...
Abstract 3D printing and ultrasound techniques are showing great promise in the evolution of human musculoskeletal tissue repair regeneration medicine. The uniqueness present study was to combine low intensity pulsed (LIPUS) advanced synergistically improve growth osteogenic differentiation mesenchymal stem cells (MSC). Specifically, polyethylene glycol diacrylate bioinks containing cell adhesive Arginine-Glycine-Aspartic acid-Serene (RGDS) peptide and/or nanocrystalline hydroxyapatite (nHA)...
Biological nanoparticles, such as exosomes, offer an approach to drug delivery because of their innate ability transport biomolecules. Exosomes are derived from cells and integral component cellular communication. However, the cargo human exosomes could negatively impact use a safe carrier. Additionally, have intrinsic yet enigmatic, targeting characteristics complex Hence, harnessing natural abilities for requires predictably these biological nanoparticles. This manuscript describes two...
Four-dimensional (4D) printing, a state-of-the-art additive manufacturing technology, enables the creation of objects capable changing shape, properties, or functionality over time in response to external stimuli. However, lack...
Two nonlinear interfacial elasticity models—interfacial decreasing linearly and exponentially with area fraction—are developed for the encapsulation of contrast microbubbles. The strain softening (decreasing elasticity) results from association between constitutive molecules encapsulation. models are used to find characteristic properties (surface tension, elasticity, viscosity parameters) a commercial agent. Properties found using ultrasound attenuation measured through suspension Dynamics...
The deformation of a viscoelastic drop suspended in Newtonian fluid subjected to steady shear is investigated using front-tracking finite-difference method. viscoelasticity modelled the Oldroyd-B constitutive equation. response with increasing relaxation time λ and varying polymeric total viscosity ratio β studied explained by examining elastic viscous stresses at interface. Steady-state was seen decrease from its value viscoelasticity. A slight non-monotonicity steady-state Deborah number...
Mechanical stimulation of bone increases mass and fracture healing, at least in part, through proliferation osteoblasts osteoprogenitor cells. Researchers have previously performed vitro studies ultrasound-induced osteoblast but mostly used fixed ultrasound settings reported widely varying inconclusive results. Here we critically investigated the effects excitation parameters low-intensity pulsed (LIPUS) on MC3T3-E1 preosteoblastic cells monolayer cultures. We a custom-designed exposure...
Subharmonic aided pressure estimation (SHAPE) is a noninvasive measurement technique based on the dependent subharmonic signal from contrast microbubbles. Here, SonoVue microbubble with sulfur hexafluoride (SF6) core, was investigated for use in SHAPE. The study uses excitations of 25–700 kPa peak negative (PNP) and 3 MHz frequency over eight pressurization cycles between atmospheric overpressures, ranging 0 to 25 (0 186 mm Hg). response characterized into two types. Unlike other...
Six models of contrast microbubbles are investigated to determine the excitation threshold for subharmonic generation. The applied a commercial agent; its characteristic parameters according each model determined using experimentally measured ultrasound attenuation. In classical perturbative result, minimum generation is not always predicted at with twice resonance frequency; instead it occurs over range frequencies from frequency. quantitative variation frequency depends on and bubble...
Abstract The effects of low intensity pulsed ultrasound (LIPUS) on proliferation and chondrogenic differentiation human mesenchymal stem cells (hMSCs) seeded 3D printed poly‐(ethylene glycol)‐diacrylate (PEG‐DA) scaffolds with varying pore geometries (square hexagonal channels) were investigated. scaffold square pores resulted in higher hMSC growth than a solid or hexagonally porous scaffold. optimal LIPUS parameters at 1.5 MHz found to be 100 mW/cm 2 20% duty cycle. stimulation increased by...
Phase shift liquid perfluorocarbon (PFC) droplets vaporizable by ultrasound into echogenic microbubble above a threshold pressure, termed acoustic droplet vaporization (ADV), are used for therapeutic and diagnostic applications. This study systematically investigated the effect of excitation frequency (2.25, 10, 15 MHz) on ADV inertial cavitation (IC) thresholds lipid-coated PFC three different cores—perfluoropentane (PFP), perfluorohexane (PFH), perfluorooctyl bromide (PFOB)—and two...
Abstract Lipid-coated microbubbles are used to enhance ultrasound imaging and drug delivery. Here we apply these along with low intensity pulsed (LIPUS) for the first time proliferation chondrogenic differentiation of human mesenchymal stem cells (hMSCs) in a 3D printed poly-(ethylene glycol)-diacrylate (PEG-DA) hydrogel scaffold. The hMSC increased up 40% after 5 days culture presence 0.5% (v/v) LIPUS contrast 18% alone. We systematically varied acoustic excitation parameters—excitation...
Variation of subharmonic response from contrast microbubbles with ambient pressure is numerically investigated for non-invasive monitoring organ-level blood pressure. Previously, several both in vitro and vivo registered approximately linear (5–15 dB) reduction 188 mm Hg change In contrast, simulated a single microbubble seen here to either increase or decrease This shown using the code BUBBLESIM encapsulated microbubbles, then underlying dynamics free bubble model. The ratio excitation...
Chemotherapeutic agents for treating cancers show considerable side effects, toxicity, and drug resistance. To mitigate the problems, we designed nucleus-targeted, echogenic, stimuli-responsive polymeric vesicles (polymersomes) to transport subsequently release encapsulated anticancer drugs within nuclei of pancreatic cancer cells. We synthesized an alkyne-dexamethasone derivative conjugated it N3–polyethylene glycol (PEG)–polylactic acid (PLA) copolymer employing Cu2+ catalyzed "Click"...