Shenzhen Key Laboratory of Smart Healthcare Engineering, Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China.
Department of Biomedical Engineering, National University of Singapore, Engineering Drive 3, Engineering Block 4, #04-08, Singapore, 117583, Singapore.
Adv Healthc Mater. 2022 May;11(10):e2102281. doi: 10.1002/adhm.202102281. Epub 2022 Feb 10.
Particulate embolic agents with calibrated sizes, which employ interventional procedures to achieve endovascular embolization, have recently attracted tremendous interest in therapeutic embolotherapies for a wide plethora of diseases. However, the particulate shape effect, which may play a critical role in embolization performances, has been rarely investigated. Here, polyvinyl alcohol (PVA)-based shape-anisotropic microembolics are developed using a facile droplet-based microfluidic fabrication method via heat-accelerated PVA-glutaraldehyde crosslinking reaction at a mild temperature of 38 C. Precise geometrical controls of the microembolics are achieved with a nearly capsule shape through regulating surfactant concentration and flow rate ratio between dispersed phase and continuous phase in the microfluidics. Two specific models are employed, i.e., in vitro decellularized rabbit liver embolization model and in vivo rabbit ear embolization model, to systematically evaluate the embolization behaviors of the nonspherical microembolics. Compared to microspheres of the same volume, the elongated microembolics demonstrated advantageous endovascular navigation capability, penetration depth and embolization stability due to their comparatively smaller radial diameter and their central cylindrical part providing larger contact area with distal vessels. Such nonspherical microembolics present a promising platform to apply shape anisotropy to achieve distinctive therapeutic effects for endovascular treatments.
具有标定尺寸的微粒栓塞剂，采用介入程序实现血管内栓塞，最近在广泛的疾病的治疗性栓塞治疗中引起了极大的关注。然而，微粒形状效应可能在栓塞性能中起关键作用，但其很少被研究。在这里，使用一种简单的基于液滴的微流控制造方法，通过在 38°C 的温和温度下进行热加速的聚乙烯醇-戊二醛交联反应，开发了基于聚乙烯醇（PVA）的形状各向异性微栓塞剂。通过在微流控中调节表面活性剂浓度和分散相与连续相之间的流速比，可以实现微栓塞剂的近胶囊形状的精确几何控制。采用两种特定的模型，即体外去细胞兔肝栓塞模型和体内兔耳栓塞模型，系统地评估了非球形微栓塞剂的栓塞行为。与具有相同体积的微球相比，由于其相对较小的径向直径和提供与远端血管更大接触面积的中央圆柱形部分，长形微栓塞剂表现出有利的血管内导航能力、穿透深度和栓塞稳定性。这种非球形微栓塞剂为实现血管内治疗的独特治疗效果应用形状各向异性提供了一个有前途的平台。
