Suresh Supraja, Black Richard A
Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK.
Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK
J Biomater Appl. 2015 Feb;29(7):1028-38. doi: 10.1177/0885328214551587. Epub 2014 Sep 22.
Intracranial pressure and volume vary considerably between hydrocephalic patients, and with age, health and haemodynamic status; if left untreated, intracranial pressure rises and the ventricular system expands to accommodate the excess cerebrospinal fluid, with significant morbidity and mortality. Cerebrospinal fluid shunts in use today have a high incidence of failure with shunt obstruction being the most serious. Conventional proximal shunt catheters are made from poly(dimethyl)siloxane, the walls of which are perforated with holes for the cerebrospinal fluid to pass through. The limited range of catheters, in terms of material selection and flow distribution, is responsible in large part for their poor performance. In this study, we present an alternative design of proximal catheter made of electrospun polyether urethane, and evaluate its performance in the presence of glial cells, which are responsible for shunt blockage. The viability and growth of cells on catheter materials such as poly(dimethyl)siloxane and polyurethane in the form of cast films, microfibrous mats and porous sponges were studied in the presence of proteins present in cerebrospinal fluid after 48 h and 96 h in culture. The numbers of viable cells on each substrate were comparable to untreated poly(dimethyl)siloxane, both in the presence and absence of serum proteins found in cerebrospinal fluid. A cell culture model of shunt obstruction was developed in which cells on electrospun polyether urethane catheters were subjected to flow during culture in vitro, and the degree of obstruction quantified in terms of hydraulic permeability after static and perfusion culture. The results indicate that a catheter made of electrospun polyether urethane would be able to maintain cerebrospinal fluid flow even with the presence of cells for the time period chosen for this study. These findings have implications for the design and deployment of microporous shunt catheter systems for the treatment of hydrocephalus.
脑积水患者的颅内压和容量差异很大，且因年龄、健康状况和血流动力学状态而异；如果不进行治疗，颅内压会升高，脑室系统会扩张以容纳多余的脑脊液，从而导致严重的发病率和死亡率。当今使用的脑脊液分流器故障率很高，其中分流梗阻最为严重。传统的近端分流导管由聚（二甲基）硅氧烷制成，其管壁上有供脑脊液通过的小孔。导管在材料选择和流量分布方面的范围有限，这在很大程度上导致了它们的性能不佳。在本研究中，我们提出了一种由电纺聚醚聚氨酯制成的近端导管的替代设计，并评估了其在存在导致分流堵塞的神经胶质细胞情况下的性能。研究了在培养48小时和96小时后，脑脊液中存在的蛋白质存在时，聚（二甲基）硅氧烷和聚氨酯等导管材料以流延膜、微纤维垫和多孔海绵形式存在时细胞的活力和生长情况。在存在和不存在脑脊液中发现的血清蛋白的情况下，每个底物上的活细胞数量与未处理的聚（二甲基）硅氧烷相当。建立了一个分流梗阻的细胞培养模型，其中将电纺聚醚聚氨酯导管上的细胞在体外培养过程中进行流动处理，并在静态和灌注培养后根据水力渗透率对梗阻程度进行量化。结果表明，即使在本研究选择的时间段内存在细胞，由电纺聚醚聚氨酯制成的导管也能够维持脑脊液流动。这些发现对用于治疗脑积水的微孔分流导管系统的设计和部署具有启示意义。
