Using low-frequency ultrasound to improve the optical clearing of porcine skin

Study on the refractive index matching effect of ultrasound on optical clearing of bio-tissues based on the derivative total reflection method

“…The results of the RI changes indicate the RI matching process in OC directly. The results of the enhancement in OC induced by the combination of glycerol and ultrasound matches previous reported results very well [11,14]. Furthermore, the water loss is also an important mechanism for the OC process.…”

“…glucose, glycerol, propylene glycol, dimethyl sulfoxide and mannitol [4][5][6][7]. To enhance the permeation of OCAs into tissues, plenty of physical and chemical methods have been introduced [5][6][7][9][10][11][12][13][14][15]. Many of them and their combinations have achieved remarkable OC effect on tissues with variety structures, such as iontophoresis, intensive pulsed light, microneedle rolling, application of ultrasound and their combination with chemical enhancers [5,[9][10][11][12][13][14].…”

“…To enhance the permeation of OCAs into tissues, plenty of physical and chemical methods have been introduced [5][6][7][9][10][11][12][13][14][15]. Many of them and their combinations have achieved remarkable OC effect on tissues with variety structures, such as iontophoresis, intensive pulsed light, microneedle rolling, application of ultrasound and their combination with chemical enhancers [5,[9][10][11][12][13][14]. The application of OC technique has achieved a significant enhancement of resolution in photoacoustic technique in recently studies [16][17][18].…”

“…Furthermore, dehydration and morphology change of collagen fibers are also proposed as important mechanisms for OC [4,6,7,9,15,20]. As common methods, optical coherent tomography (OCT) and Vis/NIR spectrograph have been applied in the investigation of OC to evaluate the efficiency [4][5][6][7]14,15].…”

“…The phenomenon of enhanced transdermal transport caused by the ultrasound application is reported as sonophoresis [5,[11][12][13][14][21][22][23][24][25], which achieves prominent enhancement in OC technique and transdermal drug delivery. The investigation on the effect of ultrasound parameters indicates that the low-frequency sonophoresis can induce a more remarkable enhancement [11,14,[21][22][23][24]. It's widely agreed that the cavitational effect is the main mechanism for the low-frequency ultrasound [22,23].…”