Department of Physics, University of Memphis, Memphis, Tennessee, United States of America.
PLoS One. 2013 Jun 14;8(6):e66348. doi: 10.1371/journal.pone.0066348. Print 2013.
Polyurea crosslinked silica aerogels are highly porous, lightweight, and mechanically strong materials with great potential for in vivo applications. Recent in vivo and in vitro studies have demonstrated the biocompatibility of this type of aerogel. The highly porous nature of aerogels allows for exceptional thermal, electric, and acoustic insulating capabilities that can be taken advantage of for non-invasive external imaging techniques. Sound-based detection of implants is a low cost, non-invasive, portable, and rapid technique that is routinely used and readily available in major clinics and hospitals.
In this study the first in vivo ultrasound response of polyurea crosslinked silica aerogel implants was investigated by means of a GE Medical Systems LogiQe diagnostic ultrasound machine with a linear array probe. Aerogel samples were inserted subcutaneously and sub-muscularly in a) fresh animal model and b) cadaveric human model for analysis. For comparison, samples of polydimethylsiloxane (PDMS) were also imaged under similar conditions as the aerogel samples.
CONCLUSION/SIGNIFICANCE: Polyurea crosslinked silica aerogel (X-Si aerogel) implants were easily identified when inserted in either of the regions in both fresh animal model and cadaveric model. The implant dimensions inferred from the images matched the actual size of the implants and no apparent damage was sustained by the X-Si aerogel implants as a result of the ultrasonic imaging process. The aerogel implants demonstrated hyperechoic behavior and significant posterior shadowing. Results obtained were compared with images acquired from the PDMS implants inserted at the same location.
聚脲交联二氧化硅气凝胶是一种具有高度多孔性、轻质和机械强度的材料，具有在体内应用的巨大潜力。最近的体内和体外研究已经证明了这种气凝胶的生物相容性。气凝胶的高度多孔性质使其具有卓越的热、电和声学绝缘能力，可用于非侵入性外部成像技术。基于声音的植入物检测是一种低成本、非侵入性、便携式和快速的技术，在主要的诊所和医院中经常使用且易于获得。
在这项研究中，首次通过使用通用电气医疗系统 LogiQe 诊断超声机和线性阵列探头，研究了聚脲交联二氧化硅气凝胶植入物的体内超声响应。气凝胶样本被插入皮下和肌肉下，分别在 a）新鲜动物模型和 b）尸体人类模型中进行分析。为了进行比较，还在类似的条件下对聚二甲基硅氧烷（PDMS）样本进行了成像。
结论/意义：当在新鲜动物模型和尸体模型中的任何一个区域插入聚脲交联二氧化硅气凝胶（X-Si 气凝胶）植入物时，它们很容易被识别。从图像推断出的植入物尺寸与实际植入物尺寸匹配，并且由于超声成像过程，X-Si 气凝胶植入物没有受到明显的损伤。气凝胶植入物表现出高回声行为和明显的后向阴影。将获得的结果与在相同位置插入的 PDMS 植入物获得的图像进行了比较。
