Research Progress of Silk Fibroin As a Drug Delivery Materials / 生物医学工程学杂志

Recently, drug delivery materials have become the hotspot of medical study. Suitable delivery material plays an important role in constructing an excellent drug delivery system. Silk fibroin is a naturally occurring protein polymer with excellent biocompatibility, remarkable mechanical properties, biodegradability and outstanding processability. Due to its unique properties, silk fibroin has become a favorable carrier material for the incorporation and delivery of a range of therapeutic agents. Based on the structure and characteristics of silk fibroin, this article provides an overview of the recent research progress of silk fibroin used as drug delivery materials.

Detection of binding capability of targeted KDR ultrasound contrast agent in vitro for evaluating endometrial receptivity / 南方医科大学学报

<p><b>OBJECTIVE</b>To prepare a new targeted liposome ultrasonic contrast agent with anti-KDR antibody that binds specifically with KDR as the main receptor of VEGF and evaluate its physical characteristics, biological activity and specific binding capability in vitro.</p><p><b>METHODS</b>A sonicator was used to prepare the biotinylated lipid micro-bubbles (MB-B), and biotin-avidin-mediated technique was used for attachment of anti-mouse KDR monoclonal antibody to the micro-bubble shell to generate MB-BAB-KDR. MB-BAB-KDR was incubated with fluorescent second antibody to assess the link condition, and the control groups were the MB-B and micro-bubbles with the antibody alone (MB-B-KDR). A parallel plate flow chamber system was used to characterize micro-bubbles attachment efficiency to KDR Fc.</p><p><b>RESULTS</b>The surface of the micro-bubbles could carry KDR antibody through the biotin-avidin bridge and MB-BAB-KDR were spherical and well-distributed. After incubation with the second antibody, MB-BAB-KDR could be observed to emit bright green fluorescence (Grade II) as compared with little or weak fluorescence in the control MB-B group (Grade 0) and MB-B-KDR group (Grade I). Targeted micro-bubbles bound to KDR Fc increased as the KDR Fc concentration increased (P<0.05).</p><p><b>CONCLUSION</b>The targeted liposome contrast agent linked with KDR antibody by biotin-avidin bridge we prepared shows an increased binding number as the KDR Fc concentration increases, which provides a novel approach to molecular imaging study of endometrial receptivity.</p>

Experiment of the ultrasound radiation force enhancement in adhesion of targeted microbubbles in vivo / 中华超声影像学杂志

Objective To investigate the effects of ultrasound radiation force(USRF) on adhering of targeted microbubbles in vivo.Methods A rat model of cremaster muscle Inflammation was developed,and microbubble(MB) or targeted microbubble of intercellular adhesion molecule-1 (MBICAM) was injected through the caudal vein.Immediately after intravenous MB or MBICAM injection,the cremaster was insonated for 5 minutes and the control group was in sham ultrasound exposure.All mice were divided into four groups randomly:① MB + false USRF; ② MB + USRF; ③ MBICAM + false USRF; ④ MBICAM + USRF.Fluorescence microscope was performed in twenty mice to evaluate microbubbles adhesion and video recordings were made with a high-resolution camera.Results The adhesion number of MBICAM was significantly greater in USRF group than that of MBICAM in false USRF group [(43.4 ± 2.1)/view vs (14.8± 1.8)/view,P =0.000].The adhesion number of MB in USRF group was greater than in false USRF group [(6.2 ± 1.3)/view vs (4.6 ± 0.9)/view].But there is no statistical significance (P =0.129).The adhesion number of MBICAM in both USRF group and false USRF group was significantly greater than the adhesion number of MB.Conclusions The ultrasound radiation force can significantly improve the adhesion of targeted microbubbles in vivo.

Value of transoral carotid ultrasonography in detecting the change of distal extracranial internal carotid artery with stenosis and occlusion in its initial segment / 中华超声影像学杂志

Objective To investigate the value of transoral carotid ultrasonography (TOCU) in detecting the change of distal extracranial internal carotid artery(ICA) with stenosis and occlusion in its initial segmen.Methods One hundred and ten patients with stenosis at least 50％ or occlusion in the initial segment of ICA diagnosed by high-frequency linear probe were enrolled as case group,while thirty two with healthy carotid arteries as control group.Both of the case and control groups were undergone high-frequency linear probe to examine CCA and the initial segment of ICA,and TOCU to observe their lumen transparency,color Doppler flow display and change of Doppler flow spectrum,even measuring the internal diameter,peak systolic velocity (PSV),end-diastolic velocity(EDV) and PSVICA/PSVCCA ratio,respectively.Digital subtraction angiography (DSA)were performed within two weeks,then compared with ultrasonography.Results 92.7％ patients were performed TOCU examination in case group and 93.8％ in control group.The internal diameter and PSV of the distal extracranial ICA became gradually smaller from control group to near occlusion group,and there were statistical significance between groups ( P ＜0.05),however,near occlusion group had no statistical significance compared with occlusion group( P ＞0.05).There were 80％ arteries having thrombus echo in occlusion group,and the others in this group having no thrombus had gloomy colour flow,even got low-velocity artery spectrum.Doppler flow spectrum of distal extracranial ICA showed characteristics of slow wave or single peak in near occlusion group,and spike shape or slow wave in 76.7 ％ arteries of 70％ ～near-occlusion stenosis group,but spike shape in 30.8％ arteries of 50％～69％ stenosis group,and the others were normal.Conclusions TOCU is useful for detecting the changing regularity of distal extracranial ICA with stenosis or occlusion in its initial segment and has the value of clinical application in association with high-frequency linear probe.

Ultrasound imaging of acute renal allograft rejection with microbubbles targeted to intercellular adhesion molecule-1 / 中华超声影像学杂志

ObjectiveTo assess the feasibility of evaluation of renal allograft acute rejection in rat withcontrast-enhancedultrasound( CEUS )andtargetedmicrobubbles.MethodsPhospholipid microbubbles targeted to intercellular adhesion molecule -1 (ICAM-1)(MBI) and control microbubbles (MB) were created by conjugating monoclonal antibody against ICAM-1 or isotype control antibody to the lipid capsule via “avidin-biotin” bridging.Ten SD rats with acute renal allograft rejection were injected intravenous of MBI and MB in random order with a 30-min interval.After 3 min of intravenous injection of microbubbles,targeted CEUS imaging was performed in all rats.And then the video intensity (VI) was determined.ResultsIn MBI group,a significant ultrasonic enhancement was observed,but it was not very obvious in MB group.Increment in VI value of transplant kidney in MBI group was great and it amounted to (27.0 ± 7.4)U,however,increment in VI value of in MB group was minor and it was merely (10.2 ± 2.4) U,Difference was evident in transplant kidney between of the two groups (P ＜ 0.05).Conclusions Molecular imaging of ICAM-1 with targeted CEUS can evaluate renal allograft acute rejection effectively.

Construction of targeted ultrasound contrast agent with anti-IgG monoclone antibody and the evaluation on the effectiveness of its targeted adhesion in vitro / 中华超声影像学杂志

Objective To construct targeted ultrasound contrast agent carried goat anti-mouse IgG antibody (UCA-IgG) and evaluate the effectiveness of its targeted adhesion using parallel plate flow chamber. Methods The ultrasound contrast agent targeted to mouse IgG was designed by conjugating monoclonal antibodies against mouse lgG to the lipid monolayer shell of the agent using biotin-streptavidin. The binding of IgG antibodies to the ultrasound contrast agent were identified by fluorescence in vitro. The attachment and detachment of UCA-IgG to mouse IgG immobilized on a culture dish were assessed in a parallel-plate flow chamber. While the plate lacked mouse IgG,or blocked with large number of goat anti-mouse IgG were served as two control groups. Results UCA-IgG issued a bright green fluorescence, while the contral lipid ultrasound contrast agent didn't show fluorescence. The number of UCA-IgG bound to mouse IgG of experimental group was greater than two control groups,increased with increasing coverslips surface antibody concentrations (P<0. 05),and there was significant positive correlation between the number of UCA-IgG bound to mouse IgG and time of combination (P<0.05). The adhesion rate of experimental group increased with shear stress before 0. 5×10-5 N/cm2 (P<0.05) and then decreased (P<0. 05). There was limited adherence of control groups to the UCA-IgG. The stess of half-maximal detachment was increased with increasing coverslips surface antibody concentrations (P<0.05). Conclusions UCA-IgG could adhere to mouse IgG in the physical conditions. It may provide strong supports for studying other targeted ultrasound contrast agent preliminary and fatherly in vitro.