Biological Effects Of Ultrasound

Mourad, Pierre D.

doi:10.1002/047134608x.w7405

Cited by 6 publications

(7 citation statements)

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“…To assess whether enhanced killing may be due to a "bioacoustic effect" (i.e., an enhanced antibiotic killing of bacteria in the presence of ultrasound [20,24]) rather than local concentrated antibiotic delivery, we exposed planktonic cells to the same treatments used for the flow cell biofilms. Stationary-phase, 48-h shake flask cultures grown at 37°C on full-strength LB broth were exposed to (i) ultrasound (20 min in a 43-kHz Branson 200 ultrasonic bath) with added ciprofloxacin (5 g/ml), (ii) ciprofloxacin only, (iii) ultrasound only, and (iv) no ultrasound or ciprofloxacin (control).…”

Section: Methodsmentioning

confidence: 99%

“…The closely packed methylene chains create a self-assembled barrier membrane that minimizes passive release. The concept of using ultrasound to induce controlled drug delivery is attractive because at low power levels it is noninvasive and has been used effectively in other areas of medical treatment and diagnosis (20). Although the characteristics of release of certain drugs from the coated pHEMA hydrogels have been documented, it remains unclear whether these hydrogels would be effective against biofilm formation and growth.…”

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confidence: 99%

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Ultrasonically Controlled Release of Ciprofloxacin from Self-Assembled Coatings on Poly(2-Hydroxyethyl Methacrylate) Hydrogels forPseudomonas aeruginosaBiofilm Prevention

Norris

Noble

Francolini

et al. 2005

Antimicrob Agents Chemother

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Indwelling prostheses and subcutaneous delivery devices are now routinely and indispensably employed in medical practice. However, these same devices often provide a highly suitable surface for bacterial adhesion and colonization, resulting in the formation of complex, differentiated, and structured communities known as biofilms. The University of Washington Engineered Biomaterials group has developed a novel drug delivery polymer matrix consisting of a poly(2-hydroxyethyl methacrylate) hydrogel coated with ordered methylene chains that form an ultrasound-responsive coating. This system was able to retain the drug ciprofloxacin inside the polymer in the absence of ultrasound but showed significant drug release when low-intensity ultrasound was applied. To assess the potential of this controlled drug delivery system for the targeting of infectious biofilms, we monitored the accumulation of Pseudomonas aeruginosa biofilms grown on hydrogels with and without ciprofloxacin and with and without exposure to ultrasound (a 43-kHz ultrasonic bath for 20 min daily) in an in vitro flow cell study. Biofilm accumulation from confocal images was quantified and statistically compared by using COMSTAT biofilm analysis software. Biofilm accumulation on ciprofloxacin-loaded hydrogels with ultrasound-induced drug delivery was significantly reduced compared to the accumulation of biofilms grown in control experiments. The results of these studies may ultimately facilitate the future development of medical devices sensitive to external ultrasonic impulses and capable of treating or preventing biofilm growth via "on-demand" drug release.

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Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

Ultrasonically Controlled Release of Ciprofloxacin from Self-Assembled Coatings on Poly(2-Hydroxyethyl Methacrylate) Hydrogels forPseudomonas aeruginosaBiofilm Prevention

Norris

Noble

Francolini

et al. 2005

Antimicrob Agents Chemother

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“…Intense focused ultrasound could form the basis of this test. Specialized ultrasound devices can focus quantifiable amounts of ultrasonic energy within a roughly cylindrically shaped volume of tissue on the order of tens of microliters that lies subcutaneous within the body [ 7 , 8 ] sufficient to cause rapid, transient, and localized increase in tissue temperature. Such devices can also cause local tissue displacement, hence localized shear forces within tissue [ 7 , 8 ].…”

Section: Introductionmentioning

confidence: 99%

Intense focused ultrasound stimulation can safely stimulate inflamed subcutaneous tissue and assess allodynia

et al. 2014

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BackgroundPotential peripheral sources of deep pain can require invasive evocative tests for their assessment. Here we perform research whose ultimate goal is development of a non-invasive evocative test for deep painful tissue.MethodsWe used a rat model of inflammation to show that intense focused ultrasound (iFU) differentially stimulates inflamed versus control tissue and can identify allodynia. To do so we applied iFU to inflamed and normal tissue below the skin of rats’ hind paws and measured the amount of ultrasound necessary to induce paw withdrawal.ResultsiFU of sufficient strength (spatial and temporal average intensities ranged from 100–350 W/cm2) caused the rat to withdraw its inflamed paw, while the same iFU applied to the contralateral paw failed to induce withdrawal, with sensitivity and specificity generally greater than 90%. iFU stimulation of normal tissue required twice the amount of ultrasound to generate a withdrawal than did inflamed tissue, thereby assessing allodynia. Finally, we verified in a preliminary way the safety of iFU stimulation with acute histological studies coupled with mathematical simulations.ConclusionsGiven that there exist systems to guide iFU deep to the skin, image-guided iFU may one day allow assessment of patient’s deep, peripheral pain generators.

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“…Two types of images were collected: shear wave elastography and B‐mode. B‐mode imaging assessed the 2‐dimensional anatomy of the brain region from the echoes returning from tissue of different density 10 . The B‐mode gain was adjusted for clear visualization of the skull.…”

Section: Methodsmentioning

confidence: 99%

Evidence of Changes in Brain Tissue Stiffness After Ischemic Stroke Derived From Ultrasound‐Based Elastography

Lee

Chu

et al. 2013

Journal of Ultrasound in Medicine

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The differences between intrahemispheric averages of shear moduli of the brains of animals with stroke at 24 and 72 hours after stroke induction likely reflect the initial formation of edema and reduction of cerebral blood flow known to develop ipsilateral to ischemic infarction, the known transient increase in intracranial pressure, as well as the known initial reduction of blood flow and subsequent development of edema in the contralateral hemisphere (diaschisis). Thus, elastography offers a possible method to detect subtle changes in brain after ischemic stroke.

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Biological Effects Of Ultrasound

Abstract: The sections in this article are Fundamentals Of Propagation and Absorption Of Ultrasound Physical and Chemical Processes Engendered By Medical Ultrasound Diagnostic Ultrasound Therapeutic Ultrasound Conclusions

Cited by 6 publications

References 107 publications

Ultrasonically Controlled Release of Ciprofloxacin from Self-Assembled Coatings on Poly(2-Hydroxyethyl Methacrylate) Hydrogels forPseudomonas aeruginosaBiofilm Prevention

Ultrasonically Controlled Release of Ciprofloxacin from Self-Assembled Coatings on Poly(2-Hydroxyethyl Methacrylate) Hydrogels forPseudomonas aeruginosaBiofilm Prevention

Intense focused ultrasound stimulation can safely stimulate inflamed subcutaneous tissue and assess allodynia

Evidence of Changes in Brain Tissue Stiffness After Ischemic Stroke Derived From Ultrasound‐Based Elastography

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