Spatiotemporal drug delivery using laser-generated-focused ultrasound system

Jin, Di; Kim, Jin-Wook; Hu, Quanyin; Jiang, Xiaoning; Gu, Zhen

doi:10.1016/j.jconrel.2015.08.033

Cited by 74 publications

(51 citation statements)

References 25 publications

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“…Enhancing particle deformation may further enhance bio-functionality. Indeed, recent reports have demonstrated that application of laser-generated focused ultrasound to microgels can enhance drug release kinetics 8,9 . While the effect of ultrasound of microgel deformability has not been studied previously, interactions between ultrasound and highly deformable droplets and microbubbles have been studied in the last few decades for diagnostic and therapeutic applications 10 .…”

Section: Introductionmentioning

confidence: 99%

Study of Poly(N-isopropylacrylamide-co-acrylic acid) (pNIPAM) Microgel Particle Induced Deformations of Tissue-Mimicking Phantom by Ultrasound Stimulation

Joshi¹,

Nandi

Chester

et al. 2018

Langmuir

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Poly (N-isopropylacrilamide) (pNIPAm) microgels (microgels) are colloidal particles that have been used extensively for biomedical applications. Typically, these particles are synthesized in the presence of an exogenous cross-linker, such as N, N′-Methylenebis (acrylamide) (BIS); however, recent studies have demonstrated that pNIPAm microgels can be synthesized in the absence of an exogenous crosslinker, resulting in the formation of ultra-low crosslinked (ULC) particles, which are highly deformable. Microgel deformability has been linked in certain cases to enhanced bioactivity when ULC microgels are used for the creation of biomimetic particles. We hypothesized that ultrasound stimulation of microgels would enhance particle deformation and that the degree of enhancement would negatively correlate with the degree of particle crosslinking. Here, we demonstrate in tissue-mimicking phantoms that using ultrasound insonification causes deformations of ULC microgel particles. Furthermore, the amount of deformation depends on the ultrasound excitation frequency and amplitude, and on the concentration of ULC microgel particles. We observed that the amplitude of deformation increases with increasing ULC microgel particle concentration up to 2.5 mg / 100 ml, but concentrations higher than 2.5 mg / 100 ml result in reduced amount of deformation. In addition, we observed that the amplitude of deformation was significantly higher at 1 MHz insonification frequency. We also report that increasing the degree of microgel crosslinking reduces the magnitude of the deformation and increases the optimal concentration required to achieve the largest amount of deformation. Stimulated ULC microgel particle deformation has numerous potential biomedical applications, including enhancement of localized drug delivery and biomimetic activity. These results demonstrate the potential of ultrasound stimulation for such applications.

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Section: Introductionmentioning

confidence: 99%

Study of Poly(N-isopropylacrylamide-co-acrylic acid) (pNIPAM) Microgel Particle Induced Deformations of Tissue-Mimicking Phantom by Ultrasound Stimulation

Joshi¹,

Nandi

Chester

et al. 2018

Langmuir

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“…Concave substrates for focusing transmitters can be purchased or printed through 3D printing. Although it is challenging to deposit a thin photoacoustic layer uniformly over a curved surface, there existed successful demonstrations . In these focused transmitters, generated photoacoustic pulses leaving from the concave surface are concentrated on the center of the radius‐of‐curvature of the concave surface (focus), having very high‐pressure amplitudes, compared to planar transmitters.…”

Section: Photoacoustic Transmitters For Novel Applicationsmentioning

confidence: 99%

“…Such capability of LGFU could be desirable for on‐demand delivery of therapeutic agents. Di et al presented drug delivery using LGFU . They used a CB‐PDMS composite for photoacoustic generation ( Figure a,b).…”

Section: Photoacoustic Transmitters For Novel Applicationsmentioning

confidence: 99%

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Efficient Photoacoustic Conversion in Optical Nanomaterials and Composites

Lee

Baac

et al. 2018

Advanced Optical Materials

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approaches. While addressing the limitations of the electrical counterparts (e.g., massive amounts of radio frequency (RF) cabling and electromagnetic (EM) interference), a photoacoustic approach for gene rat ing high-amplitude ultrasound has created new opportunities.Active research on efficient photo acoustic materials has started with the development of photoacoustic contrast mediums (e.g., exogenous contrast particles) for contrast enhancement. [3][4][5] Recent advances in nanofabrication technologies have allowed to develop more efficient photoacoustic contrast mediums, [3] such as metal nanoparticles having enhanced optical absorption due to optical resonance. Later, by coating such nanoparticles on a flat substrate, layered structures were developed for generating high-amplitude ultrasound. Among many nanoparticles, gold nanoparticles were widely used owing to strong resonance. [6] In fact, these initial efforts to increase photoacoustic conversion were focused on increasing light absorption, while the critical role of thermal expansion for photoacoustic generation were often overlooked.To enhance thermal expansion for photoacoustic generation, researchers have started to fabricate composite materials, composed of light-absorbing materials mixed with polymers with high thermal expansion coefficients. These polymer-based composites significantly enhance photoacoustic conversion efficiency. Among many polymers, polydimethylsiloxane (PDMS) is exclusively used because of its high thermal expansion, optical transparency, and acoustic impedance comparable to that of water. [7][8][9][10][11] Photoacoustic pulses generated with PDMSbased composites have the characteristics of high amplitude and high frequency, which have enabled interesting applications such as cavitation-based therapy [12] and imaging. [13] For photoacoustic composites, there are a myriad of light-absorbing nanomaterials such as metal absorbers [6] and carbon nanomaterials (e.g., carbon black (CB), [14] carbon nanotube (CNT), [7,10] carbon nanofiber (CNF), [9] candle soot (CS), [8] and reduced graphene oxide (rGO) [15] ). These light-absorbing materials of nanometer sizes have an advantage over microscale absorbing materials [7] in facilitating heat transfer from the light absorbers into the surrounding mediums. Such facilitated heat transfer is another key factor that contributes to photoacoustic energy conversion.In this Review, we will start with general considerations of photoacoustic generation in nanomaterial composites. Various photoacoustic composites enabling interesting applications will be introduced. In addition, recent efforts will be reviewed from an application perspective. Also, we will discuss outlook and future directions.Photoacoustic pulses generated by pulsed laser irradiation have the characteristics of high frequency and wide bandwidth, which are desirable for imaging and sensing. Efficient photoacoustic composites have been developed for fabricating photoacoustic transmitters capable of generating highamplitude ultrasound....

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“…The Gu and Jiang groups utilized laser-generated-focused ultrasound (LGFU) to trigger drug release from the microgel (Figure 5) [36]. Compared to traditional ultrasound triggered drug delivery systems, LGFU showed higher resolution and reduced heating effect to normal tissue.…”

Section: Organic Nanomaterials-based Photoacoustic Therapymentioning

confidence: 99%

Photoacoustic Drug Delivery

Zhang

Kahkoska

et al. 2017

Sensors

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Photoacoustic (PA) technology holds great potential in clinical translation as a new non-invasive bioimaging modality. In contrast to conventional optical imaging, PA imaging (PAI) enables higher resolution imaging with deeper imaging depth. Besides applications for diagnosis, PA has also been extended to theranostic applications. The guidance of PAI facilitates remotely controlled drug delivery. This review focuses on the recent development of PAI-mediated drug delivery systems. We provide an overview of the design of different PAI agents for drug delivery. The challenges and further opportunities regarding PA therapy are also discussed.

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Spatiotemporal drug delivery using laser-generated-focused ultrasound system

Cited by 74 publications

References 25 publications

Study of Poly(N-isopropylacrylamide-co-acrylic acid) (pNIPAM) Microgel Particle Induced Deformations of Tissue-Mimicking Phantom by Ultrasound Stimulation

Study of Poly(N-isopropylacrylamide-co-acrylic acid) (pNIPAM) Microgel Particle Induced Deformations of Tissue-Mimicking Phantom by Ultrasound Stimulation

Efficient Photoacoustic Conversion in Optical Nanomaterials and Composites

Photoacoustic Drug Delivery

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