scholarly journals A Review of the Combination Therapy of Low Frequency Ultrasound with Antibiotics

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Yun Cai ◽  
Jin Wang ◽  
Xu Liu ◽  
Rui Wang ◽  
Lei Xia
Keyword(s):  
Combination Therapy ◽  
Bacterial Infections ◽  
Bacterial Resistance ◽  
Low Frequency ◽  
Bactericidal Effect ◽  
Low Frequency Ultrasound ◽  
Biofilm Bacteria ◽  
Frequency Ultrasound

Single antimicrobial therapy has been unable to resist the global spread of bacterial resistance. Literatures of availablein vitroandin vivostudies were reviewed and the results showed that low frequency ultrasound (LFU) has a promising synergistic bactericidal effect with antibiotics against both planktonic and biofilm bacteria. It also can facilitate the release of antibiotics from medical implants. As a noninvasive and targeted therapy, LFU has great potential in treating bacterial infections. However, more in-depth and detailed studies are still needed before LFU is officially applied as a combination therapy in the field of anti-infective treatment.

scholarly journals Low-frequency ultrasound can drive the transport of nanoparticles and molecules in polymer gels for biotechnology applications

2019 ◽  
Vol 3 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Donald K. Martin
Keyword(s):  
Direct Contact ◽  
Ultrasonic Transducer ◽  
Low Frequency ◽  
Polymer Gels ◽  
Acoustic Power ◽  
Outer Retina ◽  
Low Frequency Ultrasound ◽  
Frequency Ultrasound

Abstract This paper reports the use of low-frequency ultrasound to influence transport in porous hydrogels with a transducer attached in direct contact with the hydrogel. This is a different configuration than for ultrasound-generating devices utilized previously for enhancing transport of molecules. The advantages of the system reported in this manuscript are that (i) much less acoustic power is required to influence the transport in the hydrogel that is in direct contact with the ultrasonic transducer, and (ii) no cavitation is induced in the hydrogel to influence the transport. This system was first tested in bench-top in vitro experiments by quantifying the transport of gold nanoparticles stimulated by low-frequency ultrasound. Then, to provide an in vivo example for potential biotechology applications, the system was demonstrated to be capable of transporting drugs across the tunics of a rabbit eye into the ocular circulation so as to target the transported drug to the outer retina.

scholarly journals Low-frequency ultrasound-mediated cytokine transfection enhances T cell recruitment at local and distant tumor sites

2020 ◽  
Vol 117 (23) ◽  
pp. 12674-12685
Author(s):  
Tali Ilovitsh ◽  
Yi Feng ◽  
Josquin Foiret ◽  
Azadeh Kheirolomoom ◽  
Hua Zhang ◽  
...  
Keyword(s):  
T Cell ◽  
Low Frequency ◽  
Fold Increase ◽  
T Cell Infiltration ◽  
Low Frequency Ultrasound ◽  
Targeted Microbubbles ◽  
Distant Tumor ◽  
Frequency Ultrasound

Robust cytotoxic T cell infiltration has proven to be difficult to achieve in solid tumors. We set out to develop a flexible protocol to efficiently transfect tumor and stromal cells to produce immune-activating cytokines, and thus enhance T cell infiltration while debulking tumor mass. By combining ultrasound with tumor-targeted microbubbles, membrane pores are created and facilitate a controllable and local transfection. Here, we applied a substantially lower transmission frequency (250 kHz) than applied previously. The resulting microbubble oscillation was significantly enhanced, reaching an effective expansion ratio of 35 for a peak negative pressure of 500 kPa in vitro. Combining low-frequency ultrasound with tumor-targeted microbubbles and a DNA plasmid construct, 20% of tumor cells remained viable, and ∼20% of these remaining cells were transfected with a reporter gene both in vitro and in vivo. The majority of cells transfected in vivo were mucin 1+/CD45−tumor cells. Tumor and stromal cells were then transfected with plasmid DNA encoding IFN-β, producing 150 pg/106cells in vitro, a 150-fold increase compared to no-ultrasound or no-plasmid controls and a 50-fold increase compared to treatment with targeted microbubbles and ultrasound (without IFN-β). This enhancement in secretion exceeds previously reported fourfold to fivefold increases with other in vitro treatments. Combined with intraperitoneal administration of checkpoint inhibition, a single application of IFN-β plasmid transfection reduced tumor growth in vivo and recruited efficacious immune cells at both the local and distant tumor sites.

Low-Frequency Ultrasound Induces Nonenzymatic Thrombolysis In Vitro

2002 ◽  
Vol 21 (6) ◽  
pp. 649-656 ◽  
Author(s):  
Max Nedelmann ◽  
B. Martin Eicke ◽  
Ernst G. Lierke ◽  
Axel Heimann ◽  
Oliver Kempski ◽  
...  
Keyword(s):  
Low Frequency ◽  
Low Frequency Ultrasound ◽  
Frequency Ultrasound

Low-frequency ultrasound bactericidal capacity study in intermittent ultrasonication process

2021 ◽  
Author(s):  
V.V. Sabelnikov ◽  
T.M. Sabelnikova ◽  
V.N. Goryacheva
Keyword(s):  
Ultrasonic Treatment ◽  
Bacterial Flora ◽  
Low Frequency ◽  
Treatment Method ◽  
Bactericidal Effect ◽  
Bactericidal Capacity ◽  
Infected Wounds ◽  
Low Frequency Ultrasound ◽  
Ultrasonication Time ◽  
Frequency Ultrasound

The low-frequency ultrasound (f = 26.5 kHz) was found to have a bactericidal effect upon the main representatives of bacterial flora: Staphylococcus, Proteus, E-coli and Pseudomanas aeruginosa. However, ultrasound suppresses bacterial flora during a comparatively long ultrasonication time ranging from 18 to 27 min. It was found that the determinant factor ensuring the bactericidal effect of low-frequency ultrasound is cavitation. To reduce the required ultrasonication time, while maintaining the high bactericidal effect, Bauman Moscow State Technical University (BMSTU) has developed a new ultrasonic treatment method designed for infected wounds and patented in the RF [8]. When implementing this method, it is proposed to intensify the cavitational effect of ultrasound through complementary physical and chemical factors: low-concentration antiseptic agents, excessive external static pressure, and optimum temperature of ultrasonicated solution. The proposed intensification of ultrasonic effect was found to reduce the sterilization time of bacterial suspensions from 5 to 7.2 times, while keeping the maximum required ultrasonication time within 5 min. The article considers further potential reduction of cavitational exposure time for tissues on the basis of earlier found aftereffect of ultrasound. This aftereffect means that a pre-sonicated solution has higher bactericidal properties than non-sonicated solutions and preserves its bactericidal capacity for specific time [11]. The article demonstrates the efficacy of the continuous ultrasonication process replacement by the intermittent process, which follows the cycle: ultrasonication – pause – ultrasonication. Experiments proved that, with optimum temporal relationship between the periods of ultrasonic exposure and rest, the complete sterilization end-time of bacterial suspensions can be reduced still more by 20…30%. Thus, the proposed intermittent ultrasonication process is an effective instrument of reducing the cavitational exposure of an organism, while maintaining its high bactericidal effect no worse than that of the continuous ultrasonication process. The research findings were successfully tested in the Traumatology department of N.N. Burdenko Main Military Clinical Hospital during the trial of the proposed method for ultrasonic treatment of infected wounds.

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