Ultrasound-induced cavitation: applications in drug and gene delivery

Paliwal, Sumit; Mitragotri, Samir

doi:10.1517/17425247.3.6.713

Cited by 94 publications

(75 citation statements)

References 165 publications

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“…Moreover, the MCB concentrations used in most animal studies are much higher than those licensed for echocontrast imaging in patients, which is important as the presence of MCB dose dependently reduces the threshold for ultrasoundinduced cavitation and associated bioeffects. 31,32,[75][76][77] This again emphasizes the need for caution and for a standardized format for reporting of USE conditions in the UEGT literature, so that comparison with the instantaneous USE parameters and total 'dose' pertaining to clinical examinations and other individual studies of UEGT can be made. The need for such a standardized reporting format has been recognized by the International Society for Therapeutic Ultrasound, and a consensus statement on this topic is under active development.…”

Section: Multiple Biophysical Effects Of Ultrasound May Contribute Tomentioning

confidence: 99%

Gene therapy progress and prospects: Ultrasound for gene transfer

2007

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Section: Multiple Biophysical Effects Of Ultrasound May Contribute Tomentioning

confidence: 99%

Gene therapy progress and prospects: Ultrasound for gene transfer

2007

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“…Several enhancement methods such as intraepidermal administration, iontophoresis, ultrasound, electroporation, chemical enhancers, and microneedles (MN) have been employed to overcome this barrier (1)(2)(3)(4)(5)(6)(7)(8)(9)(10) and new minimally invasive techniques are continually being investigated. While chemical enhancers have been widely investigated for enhancing drug permeation levels, they tend to disrupt the lipid bilayers of the stratum corneum.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Microchannels Created by Metal Microneedles: Formation and Closure

Kalluri

Kolli²,

Banga

2011

AAPS J

119

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Abstract. Transdermal delivery of therapeutic agents for cosmetic therapy is limited to small and lipophilic molecules by the stratum corneum barrier. Microneedle technology overcomes this barrier and offers a minimally invasive and painless route of administration. DermaRoller ® , a commercially available handheld device, has metal microneedles embedded on its surface which offers a means of microporation. We have characterized the microneedles and the microchannels created by these microneedles in a hairless rat model, using models with 370 and 770 μm long microneedles. Scanning electron microscopy was employed to study the geometry and dimensions of the metal microneedles. Dye binding studies, histological sectioning, and confocal microscopy were performed to characterize the created microchannels. Recovery of skin barrier function after poration was studied via transepidermal water loss (TEWL) measurements, and direct observation of the pore closure process was investigated via calcein imaging. Characterization studies indicate that 770 μm long metal microneedles with an average base width of 140 μm and a sharp tip with a radius of 4 μm effectively created microchannels in the skin with an average depth of 152.5±9.6 μm and a surface diameter of 70.7±9.9 μm. TEWL measurements indicated that skin regains it barrier function around 4 to 5 h after poration, for both 370 and 770 μm microneedles. However, direct observation of pore closure, by calcein imaging, indicated that pores closed by 12 h for 370 μm microneedles and by 18 h for 770 μm microneedles. Pore closure can be further delayed significantly under occluded conditions.

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“…Intracellular delivery by sonication has been shown in mammalian cells to be heterogeneous, where levels of uptake vary widely within an exposed cell population (Guzman et al 2001b). Applications of intracellular delivery using ultrasound have largely focused on biomedical needs, including drug and gene delivery studies in vitro and in vivo (Pitt et al 2004;Bekeredjian et al 2005;Paliwal and Mitragotri 2006).…”

Section: Introductionmentioning

confidence: 99%

Influence of the Cell Wall on Intracellular Delivery to Algal Cells by Electroporation and Sonication

Azencott

Peter

Prausnitz

2007

Ultrasound in Medicine & Biology

106

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To assess the cell wall's role as a barrier to intracellular delivery, wild-type Chlamydomonas reinhardtii algal cells and mutant cells lacking a cell wall were exposed to electroporation or sonication. Flow cytometry determined intracellular uptake of calcein and bovine serum albumin (BSA) and loss of cell viability as functions of electroporation transmembrane potential and acoustic energy. Electroporation of wild-type cells increased calcein uptake with increasing transmembrane potential, but delivered much less BSA. Electroporation of wall-deficient cells had similar effects on calcein uptake, but increased BSA uptake as much as 7.5-fold relative to wild-type cells, which indicated that the cell wall was a significant barrier to BSA delivery during electroporation. Sonication of wild-type cells caused calcein and BSA uptake at similar levels. This suggests that the cell wall barrier to BSA delivery can be overcome by sonication. Increased electroporation transmembrane potential or acoustic energy also caused increased loss of cell viability, where walldeficient cells were especially susceptible to lysis. Overall, we believe this is the first study to compare the effects of electroporation and sonication in a direct fashion in any cell type. Specifically, these findings suggest that electroporation primarily transports molecules across the plasma membrane, because its mechanism is specific to lipid bilayer disruption, whereas sonication transports molecules across both the plasma membrane and cell wall, because it non-specifically disrupts cell-surface barriers.

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Ultrasound-induced cavitation: applications in drug and gene delivery

Cited by 94 publications

References 165 publications

Gene therapy progress and prospects: Ultrasound for gene transfer

Gene therapy progress and prospects: Ultrasound for gene transfer

Characterization of Microchannels Created by Metal Microneedles: Formation and Closure

Influence of the Cell Wall on Intracellular Delivery to Algal Cells by Electroporation and Sonication

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