In situ ultrasound imaging of silk hydrogel degradation and neovascularization
In situ ultrasound imaging of silk hydrogel degradation and neovascularization
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DOI：
10.1002/term.1981
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发表时间：
2017-03-01
影响因子：
3.3
通讯作者：
Wang, Xiaoqin
中科院分区：
文献类型：
--
作者：
Leng, Xiaoping;Liu, Bin;Wang, Xiaoqin
超声（US）是一种在不牺牲动物的情况下监测生物材料植入物的形态和功能变化的有用技术。对比增强超声（CEUS）沿着二维（2D）US用于表征丝蛋白（8重量%）水凝胶植入物在大鼠体内的生物降解和新生血管形成。在Wistar大鼠（n=6）的后肢大腿肌肉之间的空间植入三角形的丝水凝胶塞。2D US中回声增强显示18周内组织向内生长伴随凝胶降解。通过Bland和Altman分析以及取出样品的可视化证实，植入凝胶的形状和尺寸在第15周之前保持定性不变。使用CEUS，通过凝胶区域中微泡的存在来监测新生血管形成，并且通过对比增强值来指示动态血管形成过程，对比增强值在第1-8周期间显示相对低的水平（<5dB），并且在第1-8周期间显示显著增加的水平。（第15周约20 dB，第18周> 35 dB），表明到该时间点，凝胶植入物中已发生主要血管化。外植体的组织学和扫描电子显微镜分析显示凝胶基质的孔径、内皮细胞和红细胞的存在以及凝胶植入物中血管的数量随时间增加，表明在该时间段内丝凝胶植入物中确实发生了降解和血管化。本研究表明，使用超声成像监测体内降解和血管化的丝素植入物在一个非破坏性的方式。版权所有（C）2015约翰威利父子有限公司
Ultrasound (US) is a useful technique to monitor morphological and functional changes of biomaterial implants without sacrificing the animal. Contrast-enhanced ultrasound (CEUS) along with two dimensional (2D) US were used to characterize the biodegradation and neovascularization of silk protein (8 wt%) hydrogel implants in rats. Cylinder-shaped silk hydrogel plugs were implanted into the space between the hind limb thigh muscles in Wistar rats (n=6). The increase of echogenicity in 2D US revealed tissue-ingrowth-accompanied gel degradation over 18 weeks. The shape and size of the implanted gels remained qualitatively unchanged until week 15, as confirmed by Bland and Altman analysis and visualization of retrieved samples. Using CEUS, neovascularization was monitored by the presence of microbubbles in the gel area, and the dynamic vascularization process was indicated by the contrast enhancement values, which showed a relatively low level (< 5 dB) during weeks 1-8 and significantly increased levels (around 20 dB at week 15 and > 35 dB at week 18), suggesting that major vascularization had occurred in the gel implants by this time point. Histological and scanning electron microscopic analysis of explants revealed time-dependent increases in the pore size of the gel matrix, the presence of endothelial and red blood cells and the number of blood vessels in the gel implants, indicating that degradation and vascularization did occur in silk gel implants during the time period. The present study demonstrates the use of US imaging formonitoring of in vivo degradation and vascularization of silk implants in a non-destructive way. Copyright (C) 2015 John Wiley & Sons, Ltd.