Polymer-coated cannulas for the reduction of backflow during intraparenchymal infusions.
Polymer-coated cannulas for the reduction of backflow during intraparenchymal infusions.
复制标题
聚合物涂层插管，用于减少实质内输注期间的回流。
DOI：
10.1007/s10856-012-4652-0
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Sarntinoranont,Malisa
中科院分区：
文献类型：
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作者：
Vazquez,LouisC;Hagel,Erik;Willenberg,BradleyJ;Dai,Wei;Casanova,Fernando;Batich,ChristopherD;Sarntinoranont,Malisa
在脑实质内输注过程中，可能会发生输注液回流或沿着套管轨迹回漏，导致治疗剂的非特异性靶向。回流的发生取决于几个变量，包括插管半径、输液流速和尖端位置。在这项研究中，原位溶胀的聚合物涂层的开发和测试与体外水凝胶实验回流减少。将涂层以双层布置施加到套管外表面，其中聚（乙烯醇）外层位于聚（环氧乙烷）和藻酸盐内层的顶部。一旦插入这些涂层套管并分配8-10 min等待水合，在0.3-0.6 μl/min的流速下，4.0 μl大分子示踪剂（伊文思蓝标记白蛋白）输注期间的回流显著减少，从而在靶区域内实现更有效的分布。聚合物涂层厚度在水合之前和之后分别为0.035和0.370 mm。此外，将回流数据拟合到模型中以估计由水合聚合物引起的有效局部压缩应力。从插入部位撤回插管后，水合聚合物涂层保留在水凝胶组织体模中留下的腔内，并在输注部位形成密封，防止针头撤回期间进一步回流。离体猪脑组织输注也显示出显著的回流减少，同时也证明了在套管移除后在组织腔中留下聚合物密封的能力。因此，这些聚合物作为针或套管涂层的应用提供了一种潜在的简单方法来改善局部药物递送的靶向。
Infusate backflow or leak-back along the cannula track can occur during intraparenchymal infusions resulting in non-specific targeting of therapeutic agents. The occurrence of backflow depends on several variables including cannula radius, infusate flow rate, and tip location. In this study, polymer coatings that swell in situ were developed and tested with in vitro hydrogel experiments for backflow reduction. Coatings were applied to the external cannula surface in a dual layer arrangement with a poly(vinyl alcohol) outer layer atop an inner poly(ethylene oxide) and alginate layer. Once these coated cannulas were inserted and allotted an 8–10 min waiting period for hydration, backflow during infusions of 4.0 μl of a macromolecular tracer (Evans Blue labeled albumin) was reduced significantly under flow rates of 0.3–0.6 μl/min, allowing for more effective distribution within targeted regions. Polymer coating thicknesses before and after hydrations were 0.035 and 0.370 mm, respectively. Also, backflow data was fit to a model to estimate the effective local compressive stress caused by the hydrated polymers. After withdrawal of the cannula from the insertion site, the hydrated polymer coatings remained within the cavity left in the hydrogel tissue phantom and formed a seal at the infusion site that prevented further backflow during needle withdrawal. Ex vivo infusions in excised porcine brain tissues also showed significant backflow reduction while also demonstrating the ability to leave a polymer seal in the tissue cavity after cannula removal. Thus, application of these polymers as needle or cannula coatings offers a potentially simple method to improve targeting for local drug delivery.