Gao Chuang, Bhattarai Pravin, Zhou Yiming, Zhang Nisi, Hameed Sadaf, Yue Xiuli, Zhao Bo
Department of Biomedical Engineering, College of Engineering, Peking University Beijing 100871 China.
School of Environment, Harbin Institute of Technology Harbin 150090 China
RSC Adv. 2019 Dec 18;9(72):41993-41999. doi: 10.1039/c9ra05118j.
The recent progress in the development of highly biocompatible nanoplatforms mostly encompasses the use of biological excipients such as red blood cells, cancer cell membranes, and also platelets. Such specialized vectors, if mimicked correctly, have intrinsic ability to navigate through the biological system and perform their intended action without eliciting any cascade of inflammatory processes. Naturally, platelets have been found to accumulate in the wound sites and also interact with circulating tumor cells (CTCs). Inspired by the targeting ability of platelets and the clinical success of ultrasound, herein we developed a novel ultrasound contrast agent (UCA) by backfilling of an insoluble gas into the platelets after lyophilization . The as-prepared platelet-based ultrasound contrast agent (P-UCA) disguised the structural integrity of the natural platelets with an average diameter of 3.1 ± 0.4 μm, and could enhance the ultrasound signal both and . Besides, we further evaluated that such platelet particles could facilitate active loading of ICG molecules for prolonged fluorescence imaging compared to the free ICG. Taking all the results together, we established that biological structures such as platelets could be repurposed as a"shell" to encapsulate gas and be further extended to load ICG for real-time ultrasound and fluorescence imaging respectively. This not only indicates many potential uses of these MBs in the diagnosis of platelet-related diseases, such as vascular damage, thrombosis, and atherosclerosis, but also serves as a powerful platform with multimodal theranostic capability after active loading of a variety of therapeutic and diagnostic agents.
高度生物相容性纳米平台开发的最新进展主要包括使用生物赋形剂，如红细胞、癌细胞膜以及血小板。如果正确模拟，此类特殊载体具有在生物系统中导航并执行其预期作用而不引发任何炎症过程级联反应的内在能力。自然地，人们发现血小板会在伤口部位聚集，并与循环肿瘤细胞（CTC）相互作用。受血小板靶向能力和超声临床成功应用的启发，在此我们通过在冻干后将不溶性气体回填到血小板中，开发了一种新型超声造影剂（UCA）。所制备的基于血小板的超声造影剂（P-UCA）保留了天然血小板的结构完整性，平均直径为3.1±0.4μm，并且在体外和体内均能增强超声信号。此外，我们进一步评估发现，与游离吲哚菁绿（ICG）相比，此类血小板颗粒能够促进ICG分子的主动负载，以实现更长时间的荧光成像。综合所有结果，我们证实血小板等生物结构可以被重新利用为包裹气体的“外壳”，并进一步扩展用于分别负载ICG以进行实时超声和荧光成像。这不仅表明这些微泡在诊断血小板相关疾病（如血管损伤、血栓形成和动脉粥样硬化）方面有许多潜在用途，而且在主动负载各种治疗和诊断剂后，还可作为一个具有多模态诊疗能力的强大平台。
