OBJECTIVETo evaluate the transdermal permeability of glucosamine sulfate solution across ex vivo rabbit dermis under ultrasound and optimize the ultrasound conditions.

METHODSThe ultrasound-assisted transdermal permeation of glucosamine sulfate solution across ex vivo rabbit dermis was tested using a simple Franz diffuse. The transdermal permeation volume and rate were calculated by measuring the concentration of glucosamine sulfate in the receptor fluid with ultraviolet spectrophotometry, and the impact of different sound intensities, irradiation time and solution concentration on solution permeation was analyzed.

RESULTSAt the ultrasound intensity of 0.2 W/cm(2), the permeation volume and rate of glucosamine sulfate both reached the maximum; no glucosamine sulfate was detected in the receptor fluid after a 5-min ultrasound irradiation. The permeation volume and rate of glucosamine sulfate increased as the irradiation time prolonged and also with increased glucosamine sulfate concentration. The dorsal and lateral skin thickness (2.0∓0.1 and 1.2∓0.1 mm, respectively) did not significantly affect the transdermal permeation of glucosamine sulfate (P>0.05).

CONCLUSIONUltrasound irradiation at 1.0 MHz for over 5 min allows glucosamine sulfate to permeate rabbit dermis, and the volume and rate of permeation increase with the irradiation time and concentration of the solution and are not affected by variations of the dermal thickness.

Administration, Cutaneous ; Animals ; Dermis ; diagnostic imaging ; drug effects ; Glucosamine ; metabolism ; In Vitro Techniques ; Permeability ; Rabbits ; Skin Absorption ; Ultrasonics ; Ultrasonography

Objective:To explore the value of transapical catheter of mitral valve repair (MVR) with Memoclip device in the management of moderate to severe and severe mitral regurgitation (MR) guided by transesophageal echocardiography (TEE).Methods:Fifteen patients with moderate to severe and severe MR in Hefei High-tech Cardiovascular Hospital from December 2021 to October 2022 were prospectively selected. Mitral valve morphology and length, regurgitation severity, left ventricular ejection fraction and pulmonary venous Doppler spectra were carefully evaluated before MVR by TEE.Intraprocedural TEE was performed to guide the MVR including transseptal catheterization, alignment of the clip delivery system, assessment of leaflet capture, clip deployment, post-clip deployment assessment, and withdrawal of the clip delivery system. The position and coaptation length of the clips, the mitral orifice morphology, residual mitral valve regurgitation and pressure gradient were evaluated after MVR.Meanwhile, the complications were monitored throughout the procedure.Results:Among the 15 patients, 12 were implanted with 1 clip and 3 were implanted with 2 clips, respectively. No complications occurred. There were 13 patients with mild regurgitation and 2 showed to moderate mitral regurgitation 1 month later after MVR, and 13 remained mild and 2 maintained moderate regurgitation 3 months later. Significant differences were found in maximal MR area (MRA-max), maximal and mean mitral valve pressure gradient (MVPG-max, MVPG-mean) and mitral valve area (MVA) among the 5 observation time points (all P<0.05). MRA-max, MVA and MVPG-mean were significantly decreased immediately and 3 months after the procedure ( P<0.001). No significant stenosis was found in mitral valve after MVR. Conclusions:MVR with Memoclip is safe, effective, easy to operate in treating patients with moderate to severe and severe MR. TEE plays a key role in perioperative MVR with Memoclip through apical catheterization.