Name: fabricating superhydrophobic polymeric materials for biomedical applications
Uploaded: 2015-08-28T14:00:00.000+00:00
Duration: 9 min 22 s
Description: Watch this Scientific Journal Video about Fabricating Superhydrophobic Polymeric Materials for Biomedical Applications at JoVE.com

Funding was provided in part by BU and the NIH R01CA149561. The authors wish to thank the electrospinning/electrospraying team including Stefan Yohe, Eric Falde, Joseph Hersey, and Julia Wang for their helpful discussions and contributions to the preparation and characterization of superhydrophobic biomaterials.

1.合成官能化聚（1,3-甘油碳酸盐共己内酯）29和聚（1,3-甘油碳酸盐共 -丙交酯）27,28。 <ol><li>单体合成。 <ol><li>溶解顺 -2-苯基-1,3-二恶烷-5-醇（50克，0.28摩尔，1当量）在500毫升无水四氢呋喃（THF）中并在氮气下搅拌在冰上。添加氢氧化钾（33.5克，0.84摩尔，3当量），细粉碎用研钵和研杵。将烧瓶在冰浴。 </li><li>添加49.6 ml的苄基溴（71.32克，0.42摩尔，1.5当量）逐滴搅拌在冰上。使反应温热至室温，搅拌24小时，在氮气氛下。 </li><li>增加150个ml的蒸馏水以溶解氢氧化钾和通过旋转蒸发除去THF。 </li><li>提取用200ml二氯甲烷（DCM）的其余材料的1-L分液漏斗中。重复萃取两次。 </li><li>干上硫酸钠有机相。 </li><li>结晶产物通过加入600毫升无水乙醇的溶液中，充分混合，并存储过夜，在-20℃下。该产品可以储存在-20℃下数天在进行后续步骤之前。 </li><li>通过一个布氏漏斗分离产物通过真空过滤和干燥的高真空。该产品可在执行后续步骤之前可存放数天。一个典型的产量这一步〜80％。 </li><li>在1升圆底烧瓶中，在暂停步骤1.1.7获得的产物。在甲醇（300毫升）中。加加入150ml 2N盐酸。回流下，在80℃进行2小时。 </li><li>蒸发溶剂并高真空下放置24小时。收率此步骤通常是&gt; 98％。 </li><li>溶解的1.1.9在THF产品（650毫升）中，并转移到一个2升圆底烧瓶中。将烧瓶在冰浴并在氮气中搅拌。添加22.4毫升氯甲酸乙酯（25.6克，0.29摩尔，2当量）在氮气下烧瓶中。 </li><li>添加32.8 ml的三乙胺（0.29摩尔，2当量）吨Ø滴液漏斗。混合用THF等体积。放置加料漏斗上的圆底烧瓶中，并保持在氮气下。 </li><li>在剧烈搅拌下，小心地分配三乙胺/ THF混合物逐滴向圆底烧瓶在冰上。注意:这是一个放热反应。为了防止温度急剧上升，加入三乙胺/ THF溶液不会高于每秒1滴。添加全卷后，搅拌4小时，反应，升温至室温，或24小时。 </li><li>滤除用布氏漏斗的三乙胺盐酸盐。蒸发溶剂在旋转蒸发器。 </li><li>添加二氯甲烷（200毫升）到该烧瓶中并加热，直到轻轻将残余物溶解。加入乙醚120ml的同时旋涡。储存在-20℃下过夜，以使产物结晶。 </li><li>筛选的单体晶体和聚合前再结晶。单体产品可以存储密封在室温下2周或在-206的温度下去。确认产品由1 H NMR，质谱和元素分析。一个典型的产率在单体合成最后一步是40-60％之间。 </li></ol></li><li>的D共聚，L-丙交酯/ε己内酯与5-苄氧基-1,3-二恶烷-2-酮。 <ol><li>热硅油浴中以140℃。 </li><li>测量2.1克5-苄基-1,3-二恶烷-2-酮（1.1制备）和将其添加到干燥的100毫升圆底烧瓶中。如果共聚D，L-丙交酯，测算出5.7克，并加入到烧瓶现在。添加磁性搅拌棒和密封用橡胶塞烧瓶中。 <ol><li>也测量的锡（II）乙基己酸240毫克（过量）在一个小的梨形烧瓶中。该聚合将导致20％摩尔甘油碳酸酯单体组合物。调整单体的质量来实现不同的单体组成。 </li></ol></li><li>冲洗两个烧瓶用氮上的Schlenk歧管5分钟，并添加4.24 ml的ε-caprolac在氮气基调。通过施加高真空（300毫乇）15分钟以除去痕量水抽空烧瓶&#39;气氛。 </li><li>充电瓶"的氛围，氮;重复这个循环两次。 </li><li>混合500μl的无水甲苯在氮气的锡催化剂。 </li><li>放置在140℃油浴中的烧瓶中单体和添加催化剂一旦所有固体都熔化。催化剂混合物递送的总体积应为〜100微升。保持在140℃不超过24小时，然后冷却该熔融聚合物至室温。立即或至少24小时后进行随后的步骤。 </li><li>溶解在二氯甲烷中的聚合物（50毫升）和沉淀到冷的甲醇（200ml）。弃去上清液，干燥的高真空下。后续的步骤可以立即或在任何点来执行。商店聚合物在冷冻直至进一步使用。典型的聚合收/转换之间80-95％。 </li><li>执行1H-NMR分析来确定共聚单体摩尔比。溶解聚合物在氘代氯仿（CDCL 3）中，在4.58-4.68 ppm的整合碳酸酯单体的苄基质子移;与在2.3 PPM（PCL）和次甲基峰亚甲基峰在5.2 PPM（PLGA）的比较该峰值区域。 </li></ol></li><li>聚合物改性:脱保护和嫁接。 <ol><li>在高压加氢容器溶解聚合物（〜7克）在120毫升四氢呋喃（THF）。称重并加入钯 - 碳催化剂（〜2克）。 </li><li>添加氢以使用氢化装置的容器中。氢化在50psi 4小时。注意:氢气极易燃烧。寻求熟悉此过程的人提供援助，并在执行此实验之前，请务必检查是否存在泄漏电源线。 </li><li>使用硅藻土填充床过滤掉钯炭催化剂。浓缩该聚合物至〜下旋转蒸发和PRECI50毫升pitate到冷甲醇。注意:干钯微粒能自燃。保持湿毛巾附近的激化为窒息火焰事件。加水至钯/碳的滤饼，以保持它成群并防止其点火。寻求熟悉这个程序的人提供援助。 </li><li>滗高真空下上清，干燥。通过注意峰值消失在4.65 ppm的（1 HNMR 在 CDCl 3中）确认总转化到游离的羟基。这些聚合物可立即使用或保存以备后用。产量的这一步骤是&gt; 90％。 </li><li>溶解在500ml无水二氯甲烷（DCM）中的聚合物和硬脂酸（1.5当量）。添加N，N&#39;-二环己基（DCC，2.0当量）和4-二甲氨基吡啶3薄片。在氮气下在室温搅拌24小时。 </li><li>通过一系列的重复的过滤和浓度的除去不溶N，N&#39;- dicyclohexylcarbourea。最后，集中溶液至50ml。 </li><li>沉淀聚合物成冷甲醇（〜175毫升），倒出上清液。干下高真空过夜的聚合物。随后使用这些聚合物的可在任何时间进行，但保留聚合物在冷冻长期储存。产量为这最后的修饰步骤一般在85％-90％。 </li></ol></li></ol> 2.定性合成共聚物<ol><li>称取〜10毫克聚合物（记录的实际质量），并添加铝样品盘中，然后密封密封。装载样品盘和卸载（参考）出锅倒入差示扫描量热。 </li><li>程序的升温和冷却（"热/冷/热"）循环:以10℃/分钟1）热从20℃至225℃，2）冷却至-75℃，在5℃/分钟， 3）热至225℃以10℃/分钟。 </li><li>确定熔点（T M），结晶（&lt;的EM&gt; T c）和玻璃化转变温度（T g）和融合（ΔH˚F热）从热迹线（如果适用）。 </li><li>溶解在THF中合成的各共聚物（1毫克/毫升），并通过一个0.02微米的PTFE过滤器进行过滤。注入溶液成凝胶渗透色谱系统和比较​​保留时间相对于一个范围的聚苯乙烯标准。 </li></ol>对于静电/电喷雾27,31 3.制备聚合物解决方案<ol><li>溶解聚合物（S）在10-40％（重量）在适当的溶剂中，例如氯仿/甲醇（5:1）为PCL或四氢呋喃/ N，N-二甲基甲酰胺（7:3）为PLGA，过夜。聚合物的该步骤所需的质量将取决于所期望的目的尺寸。 注意:例如，以产生大约300微米的厚度10厘米×10厘米网眼1克，通常需要。值得一提的是，材料的损耗西文，可能会发生在后续步骤中这个协议，如​​溶液转移到注射器（特别是粘性溶液）中，并从存在于可选连接管和针头壳体本身死体积，这将减少电纺丝过程的产量。这些减少产量可能导致高达20％的材料损失，并建议，以扩大1.5倍来预测这些损失，也包括那些与尝试此过程的第一次时优化静电参数相关联的损失。 <ol><li>通过改变总的聚合物浓度，以从更浓的溶液预期较大纤维控制纤维尺寸。为适度增强疏水性的，可以使用10％（以聚合物总质量计）的超疏水掺杂剂。对于极疏水性/超疏水材料，使用30-50％的掺杂剂和/或减少总的聚合物浓度（即，减小的纤维尺寸）。这些解决方案的后续工作可能会PERFORmed指第二天或之后一周内。 </li><li>对于电喷雾，准备在较低浓度（即，2-10％）在适当的溶剂如氯仿溶液。像静电纺丝，调节粒径通过改变聚合物浓度。 </li></ol></li><li>涡聚合物溶液充分混合。允许大气泡平息（5分钟）。 </li><li>负载溶液到玻璃注射器。取决于溶液的粘度，它可能是最容易取出柱塞和直接将溶液倒入注射器。一块惰性，软管可能静电纺丝设置中帮助操作性。倒置注射器通过软管/针组件取代空气。 </li></ol> 4.静电/电喷雾聚合物解决方案<ol><li>负载注射器到注射器泵中，设置总体积（例如，4.5毫升），在其中分配该溶液的速率（例如，5毫升/小时）。 </li><li>覆盖集电板与luminum箔缓解后续的拆卸和运输。固定箔沿外边缘遮蔽胶带​​。 </li><li>装上高压直流（HVDC）电源线到针尖。此针尖到收集器的距离是考虑，因为它1）影响的电场在给定电压的一个重要变量，和2）其收集期间影响纤维的溶剂和随后干燥的蒸发。 <ol><li>作为第一次尝试中，使用一个尖 - 集电极间距15厘米。注意:有高压和易燃溶剂参与静电/电喷雾。提供足够的通风外排，从不触碰注射器/针或打开机壳，直到完全确定高压直流电源是关闭的。 </li></ol></li><li>如果静电/电喷雾的大面积覆盖，打开旋转和平移收集桶。否则，继续下一步。 </li><li>启动注射泵。 </li><li>打开和调整高电压年龄源获得可接受的泰勒锥。如果该溶液在针尖下垂，提高电压。如果多个射流形成，降低电压。除了这些调整，可能有必要调整尖端 - 集电极距离如果纤维/颗粒出现湿或者如果调整电压并不能充分解决的拖动液滴在针尖。 注:有关详细的故障排除，请参阅里奇和他的同事47综合电纺丝优化过程。电喷一般会涉及到较高的电压和较低的溶液浓度比静电。 </li><li>关闭高电压源，然后注射泵和电动鼓（如果适用）。允许电纺丝外壳继续通气30分钟。 </li><li>从收集器删除网/涂料。允许痕量溶剂在通风橱中蒸发过夜。材料可在室温下保存为至少两周（PLGA）或两个个月（PCL）。步骤4.5-4.8可以以任何顺序来执行。 </li></ol> 5.表征纤维和颗粒尺寸光学显微镜和扫描电子显微镜<ol><li>光镜<ol><li>如果产生静电网，切割和安装它的薄部分在载玻片上。 </li><li>观察纤维直径，节点特性（斑点或分立），以及纤维形状（ 即 ，串珠，平，直/波状）。理想的静电纤维网眼均匀，直线或波浪，和珠免费的。 </li></ol></li><li>扫描电子显微镜（SEM） <ol><li>剪切和安装在使用导电铜带铝SEM存根网格或涂层表面。电纺纤维和电喷雾涂层也可以通过SEM观察通过预先纤维/颗粒在磁带上直接沉积。 </li><li>大衣网/涂层薄（〜4 nm）的金/钯通过溅射涂层。 </li><li>加载存根到SEM室，观察1-2千电子伏。一个250X放大倍率化提供了物质的一般地形评估，而较高的放大倍数显示其他纤维和颗粒的功能，如层次图案的极其超疏水性纤维和互联的颗粒涂层。 </li></ol></li></ol> 6.确定非润湿性能的<ol><li>推进和使用量变化的方法后退水接触角测量<ol><li>切上的接触角测角器的阶段目或涂覆的材料（如果可能的话），并代替薄（0.5厘米×5厘米）的条。 </li><li>捕捉水滴轮廓在分配它（从24 AWG注射器针头）在材料表面。 <ol><li>要做到这一点，开始用一种近似5微升下降，并与材料表面接触。继续缓慢添加量（20-25微升）和捕获液滴的图像，它表示水前进接触角。相比液滴针尖要小，和ThË毛细管长度应大于液滴，以尽量减少小滴形状的失真。 </li></ol></li><li>退出同样下降的同时，捕捉它的下降曲线。重复上几个样品的分立表面位置来报告的平均值 - 通常，10次测量都前进和后退接触角是足够这些材料来表征。 </li></ol></li><li>通过修改探测液体确定材料的临界表面张力。 <ol><li>制备在乙醇，丙二醇，或乙二醇含量不同的解决方案，因为这些混合物都已知表面张力的99-101。 <ol><li>或者，使用的溶剂具有不同表面张力，例如，水（72达因/厘米），丙三醇（64达因/厘米），二甲基亚砜（44达因/厘米），苄醇（39达因/厘米），1,4-二恶烷（33达因/厘米），1-辛醇（28达因/厘米），和丙酮（25达因/厘米）。重要的是要使用溶剂不会溶解聚合物，因为这些将混淆的结果。此外，要注意的是，除了表面张力，这些液体具有不同的粘度，这可能会影响接触角测量，是该技术的限制是重要的。 </li><li>测量这些溶液探测在材料表面的接触角。积接触角为表面张力的函数。 </li></ol></li></ol></li></ol> 7.检测网格31的散装润湿<ol><li>观察水渗透到3D网格采用微型计算机断层扫描（μCT）。 <ol><li>准备一个80毫克/毫升的溶液Ioxaglate的（一种碘造影剂）的水。 </li><li>淹没在这些解决方案网格和孵化，在37℃;使用70 KVP管电压，114微安的电流周期性地测量造影剂（水）渗透通过μCT（18微米3体素分辨率），以及一个300毫秒的积分时间。 </li><li>使用图像处理软件，测量像素INTENS性在整个网格，在那里明亮的像素代表水渗入的厚度。选择一个像素阈值（〜1500），这些高强度代表水的渗透。 </li></ol></li></ol> 8.测试网格的力学性能<ol><li>切啮合到1厘米×7厘米及地点的拉​​伸试验装置的夹具之间。测量精确的宽度，长度和厚度。 </li><li>三个样品进行延伸的斜坡测试。绘制使用这些数据来确定弹性模量，极限抗拉强度和延伸率，在断的应力 - 应变曲线。 </li></ol>

The authors declare that they have no competing financial interests.

我们的方法从生物医用高分子构建超疏水材料结合合成高分子化学与静电和电喷雾的聚合物加工技术。这些技术提供任一纤维或颗粒，分别。具体地，基于聚己内酯和聚（丙交酯共 -glycolide）超疏水性材料使用的是这种策略制备。通过改变疏水性共聚物组合物，在最终的聚合物共混物百分之共聚物，纤维/颗粒尺寸，总聚合物的重量百分比，和制造条件，所得到的静电/电喷雾材料的润湿性受...

超疏水表面通常被分类为显示出明显的水接触角大于150°的低接触角滞后。这些表面通过引入对低表面能材料的高表面粗糙度建立所得空气-液体-固体界面抵抗润湿1-6制造。根据不同的制造方法，薄或多层超疏水表面，多层超疏水基底涂层，或甚至散装超疏水结构可以制备。此永久或半永久性的防水性]是用于制备自清洁面 7，微流体装置8，防污细胞/蛋白质表面9,10，减阻表面11，和药物递送装置一个有用的性质-12- 15。最近，刺激响应超疏水性材料被描述其中非润湿湿润状态是通过化学引发，物理或环境因素（例如，光，pH，温度，超声，和施加的电势/电流）14,16-20，和这些材料都发现使用其他应用程序21-25。 第一个合成超疏水表面被处理材料的表面与methyldihalogenosilanes 26制备，并且是用于生物医学应用价值有限，所用的材料是不适合在体内使用 。在此，我们描述了从生物相容性的聚合物制备表面和体超疏水材料。我们的方法需要电纺丝或电喷雾含有可生物降解的，生物相容的脂族聚酯作为主要组分，掺杂有所述聚酯和硬脂酸改性的聚（甘油碳酸酯）27-30组成的疏水性共聚物的聚合物混合物。的制造技术提供增强的表面粗糙度和孔隙度上和fibe内RS或颗粒，分别，而采用的共聚物掺杂剂提供了一种低表面能聚合物，融合与聚酯，并且可以稳定地静电纺丝或电喷雾27,31,32。 脂族可生物降解的聚酯如聚（乳酸）（PLA），聚（乙醇酸）（PGA），聚（乳酸- 共 -glycolic乙酸）（PLGA），和聚己内酯（PCL）是在临床上批准的设备中使用的聚合物和在由于它们的非毒性，生物降解性，并且易于合成33的生物医学材料研究突出。 PGA和PLGA开张的诊所在1960年的生物可吸收缝合线和70年代初期，分别为34-37。从那时起，这些聚（羟基酸）已被加工成各种其它应用程序特定的形状因子，例如微38,39和纳米颗粒40,41，晶片/光盘42，啮合27,43，泡沫44和电影45 </sup&gt;。 脂族聚酯，以及生物医学兴趣的其它聚合物，可以静电纺丝来生产纳米或微纤维网状结构具有高的表面积和孔隙率以及拉伸强度。 表1列出了合成聚合物静电关于各种生物医学应用和它们的相应参考。静电和电喷雾的快速商用的可扩展技术。这两种类似的技术依赖于施加高电压（静电斥力）克服的聚合物溶液的表面张力/融化在注射器泵的设置，因为它是针对一种接地目标46,47。当这种技术用于与低表面能的聚合物结合（疏水性聚合物如聚（caprolactone- 共 -甘油单硬脂酸酯）），将得到的材料表现超疏水性。 为了说明这一点一般合成和材料加工方法从生物医学聚合物构建超疏水材料中，我们描述超疏水polycaprolactone-和聚（丙交酯共 -glycolide）基材料作为代表性实例的合成。各共聚物的掺杂剂的聚（caprolactone- 共 -甘油单硬脂酸酯）和聚（丙交酯共 -甘油单硬脂酸酯）被首先合成，然后混合以聚己内酯和聚（丙交酯共 -glycolide），分别和最后电纺丝或电喷雾。所得到的材料的特征在于通过SEM成像和接触角测角器，并测试其在体外和体内的生物相容性。最后，散湿通过三维超疏水网格使用造影剂增强microcomputed断层扫描进行检查。

<table><tbody><tr><td>Silicone oil</td><td>Sigma-Aldrich</td><td>85409</td><td></td></tr><tr><td>Cis-2-Phenyl-1,3-dioxan-5-ol</td><td>Sigma-Aldrich</td><td>13468</td><td></td></tr><tr><td>Benzyl bromide</td><td>Sigma-Aldrich</td><td>B17905</td><td>Toxic, lacrymator/eye irritant, use in chemical fume hood</td></tr><tr><td>Potassium hydroxide</td><td>Sigma-Aldrich</td><td>221473</td><td>Corrosive</td></tr><tr><td>Rotary evaporator</td><td>Buchi</td><td>R-124</td><td></td></tr><tr><td>High-vacuum pump</td><td>Welch</td><td>8907</td><td></td></tr><tr><td>Nitrogen, ultra high purity</td><td>Airgas</td><td>NI UHP300</td><td>Compressed gas</td></tr><tr><td>Tetrahydrofuran, stabilized with BHT</td><td>Pharmaco-Aaper</td><td>346000</td><td>Flammable. Dried through column of XXX</td></tr><tr><td>Dichloromethane</td><td>Pharmaco-Aaper</td><td>313000</td><td>Flammable, toxic.</td></tr><tr><td>Separatory funnel (1 L)</td><td>Fisher Scientific</td><td>13-678-606</td><td></td></tr><tr><td>Sodium sulfate</td><td>Sigma-Aldrich</td><td>239313</td><td></td></tr><tr><td>Ethanol, absolute</td><td>Pharmaco-Aaper</td><td>111USP200</td><td>Flammable, toxic.</td></tr><tr><td>Buchner funnel</td><td>Fisher Scientific</td><td>FB-966-F</td><td></td></tr><tr><td>Methanol</td><td>Pharmaco-Aaper</td><td>339000ACS</td><td>Flammable, toxic.</td></tr><tr><td>Hydrochloric acid</td><td>Sigma-Aldrich</td><td>320331</td><td>Corrosive. Diluted to 2N in distilled water.</td></tr><tr><td>Ethyl chloroformate, 97%</td><td>Sigma-Aldrich</td><td>185892</td><td>Toxic, flammable, harmful to environment</td></tr><tr><td>Triethylamine (anhydrous)</td><td>Sigma-Aldrich</td><td>471283</td><td>Toxic, flammable, harmful to environment</td></tr><tr><td>Diethyl ether</td><td>Pharmaco-Aaper</td><td>373ANHACS</td><td>Highly flammable. Purified through XXX column.</td></tr><tr><td>3,6-Dimethyl-1,4-dioxane-2,5-dione (D,L-lactide)</td><td>Sigma-Aldrich</td><td>303143</td><td></td></tr><tr><td>Tin (II) ethylhexanoate</td><td>Sigma-Aldrich</td><td>S3252</td><td>Toxic.</td></tr><tr><td>&amp;epsilon;-caprolactone (97%)</td><td>Sigma-Aldrich</td><td>704067</td><td></td></tr><tr><td>Toluene, anhydrous</td><td>Sigma-Aldrich</td><td>244511</td><td>Flammable, toxic.</td></tr><tr><td>Glass syringe</td><td>Hamilton Company</td><td>1700-series</td><td></td></tr><tr><td>Deuterated chloroform</td><td>Cambridge Isotopes Laboratories, Inc.</td><td>DLM-29-10</td><td>Toxic</td></tr><tr><td>Nuclear magnetic resonance instrument</td><td>Varian</td><td>V400</td><td></td></tr><tr><td>Palladium on carbon catalyst</td><td>Strem Chemicals, Inc.</td><td>46-1707</td><td></td></tr><tr><td>Hydrogenator unit</td><td>Parr</td><td>3911</td><td></td></tr><tr><td>Hydrogenator shaker vessel</td><td>Parr</td><td>66CA</td><td></td></tr><tr><td>Hydrogen</td><td>Airgas</td><td>HY HP300</td><td>Highly flammable.</td></tr><tr><td>Diatomaceous earth</td><td>Sigma-Aldrich</td><td>22140</td><td></td></tr><tr><td>2H,2H,3H,3H-perflurononanoic acid</td><td>Oakwood Products, Inc.</td><td>10519</td><td>Toxic.</td></tr><tr><td>Stearic acid</td><td>Sigma-Aldrich</td><td>S4751</td><td></td></tr><tr><td>N,N&amp;rsquo;-dicyclohexylcarbodiimide</td><td>Sigma-Aldrich</td><td>D80002</td><td>Toxic, irritant.</td></tr><tr><td>4-(dimethylamino) pyridine</td><td>Sigma-Aldrich</td><td>107700</td><td>Toxic.</td></tr><tr><td>Hexanes</td><td>Pharmaco-Aaper</td><td>359000ACS</td><td>Toxic, flammable.</td></tr><tr><td>Gel permeation chromatography (GPC) system</td><td>Rainin</td><td></td><td></td></tr><tr><td>GPC column</td><td>Waters</td><td>WAT044228</td><td></td></tr><tr><td>Differential scanning calorimeter</td><td>TA Instruments</td><td>Q100</td><td></td></tr><tr><td>Chloroform</td><td>Pharmaco-Aaper</td><td>309000ACS</td><td>Toxic.</td></tr><tr><td>N,N-dimethylformamide</td><td>Sigma-Aldrich</td><td>227056</td><td>Toxic, flammable.</td></tr><tr><td>Polycaprolactone, MW 70-90 kg/mol</td><td>Sigma-Aldrich</td><td>440744</td><td></td></tr><tr><td>Poly(lactide-co-glycolide), MW 136 kg/mol</td><td>Evonik Industries</td><td>LP-712</td><td></td></tr><tr><td>10 ml glass syringe</td><td>Hamilton Company</td><td>81620</td><td></td></tr><tr><td>18 AWG blunt needle</td><td>BRICO Medical Supplies</td><td>BN1815</td><td></td></tr><tr><td>Electrospinner enclosure box</td><td>Custom-built</td><td>N/A</td><td>Made of acrylic panels</td></tr><tr><td>High voltage DC supply</td><td>Glassman High Voltage, Inc.</td><td>PS/EL30R01.5</td><td>High voltages, electrocution hazard</td></tr><tr><td>Linear (translating) stage</td><td>Servo Systems Co.</td><td>LPS-12-20-0.2</td><td>Optional</td></tr><tr><td>Programmable motor &amp;amp; power supply</td><td>Intelligent Motion Systems, Inc.</td><td>MDrive23 Plus</td><td>Optional</td></tr><tr><td>24V DC motor &amp;amp; power supply</td><td>McMaster-Carr</td><td>6331K32</td><td>Optional</td></tr><tr><td>Aluminum collector drum</td><td>Custom-built</td><td></td><td>Optional</td></tr><tr><td>Syringe pump</td><td>Fisher Scientific</td><td>78-0100I</td><td></td></tr><tr><td>Inverted optical microscope</td><td>Olympus</td><td>IX70</td><td></td></tr><tr><td>Scanning electron microscope</td><td>Carl Zeiss</td><td>Supra V55</td><td></td></tr><tr><td>Conductive copper tape</td><td>3M</td><td>16072</td><td></td></tr><tr><td>Aluminum SEM stubs</td><td>Electron Microscopy Sciences</td><td>75200</td><td></td></tr><tr><td>Contact angle goniometer</td><td>Kruss</td><td>DSA100</td><td></td></tr><tr><td>Propylene glycol</td><td>Sigma-Aldrich</td><td>W294004</td><td>Toxic.</td></tr><tr><td>Ethylene glycol</td><td>Sigma-Aldrich</td><td>324558</td><td>Toxic.</td></tr><tr><td>Ioxaglate</td><td>Guerbet</td><td></td><td></td></tr><tr><td>Fetal bovine serum</td><td>American Type Culture Collection</td><td>30-2020</td><td></td></tr><tr><td>Micro-computed tomography instrument</td><td>Scanco</td><td></td><td></td></tr><tr><td>Image analysis software (Analyze)</td><td>Mayo Clinic</td><td></td><td></td></tr><tr><td>Tensile tester</td><td>Instron</td><td>5848</td><td></td></tr><tr><td>Micrometer</td><td>Multitoyo</td><td>293-340</td><td></td></tr><tr><td>Calipers</td><td>Fisher Scientific</td><td>14-648-17</td><td></td></tr></tbody></table>

fabricating superhydrophobic polymeric materials for biomedical applications

超疏水材料，具有表面具有永久的或亚稳的不可润湿的状态，是对于一些生物医学和工业应用的兴趣。在这里，我们描述了如何静电或电喷射含有可生物降解的，生物相容的脂肪族聚酯（ 例如 ，聚己内酯和聚（丙交酯共 -glycolide））的聚合物混合物中，作为主要组分，掺杂有所述聚酯和stearate-构成的疏水共聚物改性的聚（甘油碳酸酯）得到超疏水性生物材料。电纺丝或电喷雾的制造技术提供增强的表面粗糙度和孔隙度，并在纤维或颗粒内，分别。使用低表面能的共聚物的掺杂物，融合与聚酯，并且可以稳定地静电纺丝或电喷雾，得到这些超疏水材料。重要参数，例如纤维的大小，共聚物组合物的掺杂剂和/或共ncentration，以及它们对润湿性的影响进行了讨论。高分子化学和工艺工程的这种组合提供了一个通用方法使用可扩展的技术，这些都可能推广到用于各种应用更广类聚合物来开发应用程序特定的材料。

通过一系列的化学转化的，官能碳酸酯单体5-苄基-1,3-二恶烷-2-酮合成，为白色结晶固体（ 图1A）。1 H NMR确认结构（图1B）和质谱法和元素分析证实了组合物。此固体然后共聚任一D，L-丙交酯或使用锡催化开环在140℃下反应ε己内酯。经沉淀提纯后，将聚合物组合物是使用1 H NMR分析通过积分苄质子化学位移在4.58-4.68 ppm或己内酯或丙交酯的次?...

Watch this Scientific Journal Video about Fabricating Superhydrophobic Polymeric Materials for Biomedical Applications at JoVE.com

Fabricating Superhydrophobic Polymeric Materials for Biomedical Applications

Two- and three-dimensional superhydrophobic polymeric materials are prepared by electrospinning or electrospraying biodegradable polymers blended with a lower surface energy polymer of similar composition.

制造超疏水高分子材料生物医学应用

Superhydrophobic materials, with surfaces possessing permanent or metastable non-wetted states, are of interest for a number of biomedical and industrial ...

fabricating-superhydrophobic-polymeric-materials-for-biomedical

Universidad de Cartagena UDEC

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Organic Chemistry

Bioengineering

Unit 1

Synthetic Polymers

SCIENTISTS IN ACTION

19.1K 次观看.  Boston University. Two- and three-dimensional superhydrophobic polymeric materials are prepared by electrospinning or electrospraying biodegradable polymers blended with a lower surface energy polymer of similar composition. 

视频: Fabricating Superhydrophobic Polymeric Materials for Biomedical Applications

Microfabricated Platforms for Mechanically Dynamic Cell Culture

The ability to systematically probe in vitro cellular response to combinations of mechanobiological stimuli for tissue engineering, drug discovery or fundamental cell biology studies is limited by current bioreactor technologies, which cannot simultaneously apply a variety of mechanical stimuli to cultured cells. In order to address this issue, we have developed a series of microfabricated platforms designed to screen for the effects of mechanical stimuli in a high-throughput format. In this protocol, we demonstrate the fabrication of a microactuator array of vertically displaced posts on which the technology is based, and further demonstrate how this base technology can be modified to conduct high-throughput mechanically dynamic cell culture in both two-dimensional and three-dimensional culture paradigms.

In this protocol, we demonstrate the fabrication of a microactuator array of vertically displaced posts on which the technology is based, and how this base technology can be modified to conduct high-throughput mechanically dynamic cell culture in both two-dimensional and three-dimensional culture paradigms.

微机械动态细胞培养平台

The ability to systematically probe in vitro cellular response to combinations of mechanobiological stimuli for tissue engineering, drug discovery or ...

科研

生物工程

Advanced Compositional Analysis of Nanoparticle-polymer Composites Using Direct Fluorescence Imaging

The fabrication of polymer-nanoparticle composites is extremely important in the development of many functional materials. Identifying the precise composition of these materials is essential, especially in the design of surface catalysts, where the surface concentration of the active component determines the activity of the material. Antimicrobial materials which utilize nanoparticles are a particular focus of this technology. Recently swell encapsulation has emerged as a technique for inserting antimicrobial nanoparticles into a host polymer matrix. Swell encapsulation provides the advantage of localizing the incorporation to the external surfaces of materials, which act as the active sites of these materials. However, quantification of this nanoparticle uptake is challenging. Previous studies explore the link between antimicrobial activity and surface concentration of the active component, but this is not directly visualized. Here we show a reliable method to monitor the incorporation of nanoparticles into a polymer host matrix via swell encapsulation. We show that the surface concentration of CdSe/ZnS nanoparticles can be accurately visualized through cross-sectional fluorescence imaging. Using this method, we can quantify the uptake of nanoparticles via swell encapsulation and measure the surface concentration of encapsulated particles, which is key in optimizing the activity of functional materials.

Here we present a reliable method to monitor the incorporation of nanoparticles into a polymer host matrix via swell encapsulation. We show that the surface concentration of cadmium selenide quantum dots can be accurately visualized through cross-sectional fluorescence imaging.

纳米粒子 - 聚合物复合材料使用直接荧光成像的先进成分分析

The fabrication of polymer-nanoparticle composites is extremely important in the development of many functional materials. Identifying the precise ...

工程学

Microfluidic Fabrication of Polymeric and Biohybrid Fibers with Predesigned Size and Shape

A &#8220;sheath&#8221; fluid passing through a microfluidic channel at low Reynolds number can be directed around another &#8220;core&#8221; stream and used to dictate the shape as well as the diameter of a core stream.&#160;Grooves in the top and bottom of a microfluidic channel were designed to direct the sheath fluid and shape the core fluid.&#160;By matching the viscosity and hydrophilicity of the sheath and core fluids, the interfacial effects are minimized and complex fluid shapes can be formed.&#160;Controlling the relative flow rates of the sheath and core fluids determines the cross-sectional area of the core fluid.&#160;Fibers have been produced with sizes ranging from 300 nm to ~1 mm, and fiber cross-sections can be round, flat, square, or complex as in the case with double anchor fibers. Polymerization of the core fluid downstream from the shaping region solidifies the fibers.&#160;Photoinitiated click chemistries are well suited for rapid polymerization of the core fluid by irradiation with ultraviolet light.&#160;Fibers with a wide variety of shapes have been produced from a list of polymers including liquid crystals, poly(methylmethacrylate), thiol-ene and thiol-yne resins, polyethylene glycol, and hydrogel derivatives. Minimal shear during the shaping process and mild polymerization conditions also makes the fabrication process well suited for encapsulation of cells and other biological components.

Two adjacent fluids passing through a grooved microfluidic channel can be directed to form a sheath around a prepolymer core; thereby&#160;determining both shape and cross-section. Photoinitiated polymerization, such as thiol click chemistry, is well suited for rapidly solidifying the core fluid into a microfiber with predetermined size and shape.

预设计尺寸和形状的聚合物纤维和生物贿赂纤维的微流体制造

A &#8220;sheath&#8221; fluid passing through a microfluidic channel at low Reynolds number can be directed around another &#8220;core&#8221; stream and ...

Preparation and High-temperature Anti-adhesion Behavior of a Slippery Surface on Stainless Steel

Anti-adhesion surfaces with high-temperature resistance have a wide application potential in electrosurgical instruments, engines, and pipelines. A typical anti-wetting superhydrophobic surface easily fails when exposed to a high-temperature liquid. Recently, Nepenthes-inspired slippery surfaces demonstrated a new way to solve the adhesion problem. A lubricant layer on the slippery surface can act as a barrier between the repelled materials and the surface structure. However, the slippery surfaces in previous studies rarely showed high-temperature resistance. Here, we describe a protocol for the preparation of slippery surfaces with high-temperature resistance. A photolithography-assisted method was used to fabricate pillar structures on stainless steel. By functionalizing the surface with saline, a slippery surface was prepared by adding silicone oil. The prepared slippery surface maintained the anti-wetting property for water, even when the surface was heated to 300 &#176;C. Also, the slippery surface exhibited great anti-adhesion effects on soft tissues at high temperatures. This type of slippery surface on stainless steel has applications in medical devices, mechanical equipment, etc.

Slippery surfaces provide a new way to solve the adhesion problem. This protocol describes how to fabricate slippery surfaces at high temperatures. The results demonstrate that the slippery surfaces showed anti-wetting for liquids and a remarkable anti-adhesion effect on soft tissues at high temperatures.

不锈钢滑面的制备及高温抗粘接性能研究

Anti-adhesion surfaces with high-temperature resistance have a wide application potential in electrosurgical instruments, engines, and pipelines. A ...

Fabrication of Superhydrophobic Metal Surfaces for Anti-Icing Applications

Several ways to produce superhydrophobic metal surfaces are presented in this work. Aluminum was chosen as the metal substrate due to its wide use in industry. The wettability of the produced surface was analyzed by bouncing drop experiments and the topography was analyzed by confocal microscopy. In addition, we show various methodologies to measure its durability and anti-icing properties. Superhydrophobic surfaces hold a special texture that must be preserved to keep their water-repellency. To fabricate durable surfaces, we followed two strategies to incorporate a resistant texture. The first strategy is a direct incorporation of roughness to the metal substrate by acid etching. After this surface texturization, the surface energy was decreased by silanization or fluoropolymer deposition. The second strategy is the growth of a ceria layer (after surface texturization) that should enhance the surface hardness and corrosion resistance. The surface energy was decreased with a stearic acid film.
The durability of the superhydrophobic surfaces was examined by a particle impact test, mechanical wear by lateral abrasion, and UV-ozone resistance. The anti-icing properties were explored by studying the ability to repeal subcooled water, freezing delay, and ice adhesion.

We illustrate several methodologies to produce superhydrophobic metal surfaces and to explore their durability and anti-icing properties.

防结冰用超疏水性金属表面的制备

Several ways to produce superhydrophobic metal surfaces are presented in this work. Aluminum was chosen as the metal substrate due to its wide use in ...

Thin Film Composite Silicon Elastomers for Cell Culture and Skin Applications: Manufacturing and Characterization

In this protocol, we present methods to fabricate thin elastomer composite films for advanced cell culture applications and for the development of skin adhesives. Two different poly-(dimethyl siloxanes) (PDMS and soft skin adhesive (SSA)), have been used for in depth investigation of biological effects and adhesive characteristics. The composite films consist of a flexible backing layer and an adhesive top coating. Both layers have been manufactured by doctor blade application technique. In the present investigation, the adhesive behavior of the composite films has been investigated as a function of the layer thickness or a variation of the Young&#39;s modulus of the top layer. The Young&#39;s modulus of PDMS has been changed by varying the base to crosslinker mixing ratio. In addition, the thickness of SSA films has been varied from approx. 16 &#181;m to approx. 320 &#181;m. Scanning electron microscopy (SEM) and optical microscopy have been used for thickness measurements. The adhesive properties of elastomer films depend strongly on the film thickness, the Young&#39;s modulus of the polymers and surface characteristics. Therefore, normal adhesion of these films on glass substrates exhibiting smooth and rough surfaces has been investigated. Pull-off stress and work of separation are dependent on the mixing ratio of silicone elastomers.
Additionally, the thickness of the soft skin adhesive placed on top of a supportive backing layer has been varied in order to produce patches for skin applications. Cytotoxicity, proliferation and cellular adhesion of L929 murine fibroblasts on PDMS films (mixing ratio 10:1) and SSA films (mixing ratio 50:50) have been conducted. We have shown here, for the first time, the side by side comparison of thin composite films manufactured of both polymers and present the investigation of their biological- and adhesive properties.

A protocol for the manufacturing process of polymeric thin film composite structures possessing either different Young&#39;s moduli or thicknesses is presented. Films are produced for advanced cell culture studies or as skin adhesives.

用于细胞培养和皮肤应用的薄膜复合硅弹性体: 制造和表征

In this protocol, we present methods to fabricate thin elastomer composite films for advanced cell culture applications and for the development of skin ...

发育生物学

Fabrication of Refractive-index-matched Devices for Biomedical Microfluidics

The use of microfluidic devices has emerged as a defining tool for biomedical applications. When combined with modern microscopy techniques, these devices can be implemented as part of a robust platform capable of making simultaneous complementary measurements. The primary challenge created by the combination of these two techniques is the mismatch in refractive index between the materials traditionally used to make microfluidic devices and the aqueous solutions typically used in biomedicine. This mismatch can create optical artifacts near the channel or device edges. One solution is to reduce the refractive index of the material used to fabricate the device by using a fluorinated polymer such as MY133-V2000 whose refractive index is similar to that of water (n = 1.33). Here, the construction of a microfluidic device made out of MY133-V2000 using soft lithography techniques is demonstrated, using O2 plasma in conjunction with an acrylic holder to increase the adhesion between the MY133-V2000 fabricated device and the polydimethylsiloxane (PDMS) substrate. The device is then tested by incubating it filled with cell culture media for 24 h to demonstrate the ability of the device to maintain cell culture conditions during the course of a typical imaging experiment. Finally, quantitative phase microscopy (QPM) is used to measure the distribution of mass within the live adherent cells in the microchannel. This way, the increased precision, enabled by fabricating the device from a low index of refraction polymer such as MY133-V2000 in lieu of traditional soft lithography materials such as PDMS, is demonstrated. Overall, this approach for fabricating microfluidic devices can be readily integrated into existing soft lithography workflows in order to reduce optical artifacts and increase measurement precision.

This protocol describes the fabrication of microfluidic devices from MY133-V2000 to eliminate artifacts that often arise in microchannels due to the mismatching refractive indices between microchannel structures and an aqueous solution. This protocol uses an acrylic holder to compress the encapsulated device, improving adhesion both chemically and mechanically.

生物医学微流体折射率匹配器件的研制

The use of microfluidic devices has emerged as a defining tool for biomedical applications. When combined with modern microscopy techniques, these devices ...

Rendering SiO2/Si Surfaces Omniphobic by Carving Gas-Entrapping Microtextures Comprising Reentrant and Doubly Reentrant Cavities or Pillars

We present microfabrication protocols for rendering intrinsically wetting materials repellent to liquids (omniphobic) by creating gas-entrapping microtextures (GEMs) on them comprising cavities and pillars with reentrant and doubly reentrant features. Specifically, we use SiO2/Si as the model system and share protocols for two-dimensional (2D) designing, photolithography, isotropic/anisotropic etching techniques, thermal oxide growth, piranha cleaning, and storage towards achieving those microtextures. Even though the conventional wisdom indicates that roughening intrinsically wetting surfaces (&#952;o &#60; 90&#176;) renders them even more wetting (&#952;r &#60; &#952;o &#60; 90&#176;), GEMs demonstrate liquid repellence despite the intrinsic wettability of the substrate. For instance, despite the intrinsic wettability of silica &#952;o &#8776; 40&#176; for the water/air system, and &#952;o &#8776; 20&#176; for the hexadecane/air system, GEMs comprising cavities entrap air robustly on immersion in those liquids, and the apparent contact angles for the droplets are &#952;r &#62; 90&#176;. The reentrant and doubly reentrant features in the GEMs stabilize the intruding liquid meniscus thereby trapping the liquid-solid-vapor system in metastable air-filled states (Cassie states) and delaying wetting transitions to the thermodynamically-stable fully-filled state (Wenzel state) by, for instance, hours to months. Similarly, SiO2/Si surfaces with arrays of reentrant and doubly reentrant micropillars demonstrate extremely high contact angles (&#952;r &#8776; 150&#176;&#8211;160&#176;) and low contact angle hysteresis for the probe liquids, thus characterized as superomniphobic. However, on immersion in the same liquids, those surfaces dramatically lose their superomniphobicity and get fully-filled within &#60;1 s. To address this challenge, we present protocols for hybrid designs that comprise arrays of doubly reentrant pillars surrounded by walls with doubly reentrant profiles. Indeed, hybrid microtextures entrap air on immersion in the probe liquids. To summarize, the protocols described here should enable the investigation of GEMs in the context of achieving omniphobicity without chemical coatings, such as perfluorocarbons, which might unlock the scope of inexpensive common materials for applications as omniphobic materials. Silica microtextures could also serve as templates for soft materials.

Rendering SiO2/Si Surfaces Omniphobic by Carving Gas-Entrapping Microtextures Comprising Reentrant and Doubly Reentrant Cavities or Pillars

This work presents microfabrication protocols for achieving cavities and pillars with reentrant and doubly reentrant profiles on SiO2/Si wafers using photolithography and dry etching. Resulting microtextured surfaces demonstrate remarkable liquid repellence, characterized by robust long-term entrapment of air under wetting liquids, despite the intrinsic wettability of silica.

通过雕刻包含可重入和双重入的腔或柱的气体镶入微纹理来渲染 SiO2/Si 曲面全功能性

We present microfabrication protocols for rendering intrinsically wetting materials repellent to liquids (omniphobic) by creating gas-entrapping ...

High-throughput Identification of Bacteria Repellent Polymers for Medical Devices

Medical devices are often associated with hospital-acquired infections, which place enormous strain on patients and the healthcare system as well as contributing to antimicrobial resistance. One possible avenue for the reduction of device-associated infections is the identification of bacteria-repellent polymer coatings for these devices, which would prevent bacterial binding at the initial attachment step. A method for the identification of such repellent polymers, based on the parallel screening of hundreds of polymers using a microarray, is described here. This high-throughput method resulted in the identification of a range of promising polymers that resisted binding of various clinically relevant bacterial species individually and also as multi-species communities. One polymer, PA13 (poly(methylmethacrylate-co-dimethylacrylamide)), demonstrated significant reduction in attachment of a number of hospital isolates when coated onto two commercially available central venous catheters. The method described could be applied to identify polymers for a wide range of applications in which modification of bacterial attachment is important.

A high-throughput microarray method for the identification of polymers which reduce bacterial surface binding on medical devices is described.

医疗器械细菌高通量鉴定驱蚊聚合物

Medical devices are often associated with hospital-acquired infections, which place enormous strain on patients and the healthcare system as well as ...

Synthesis of Hydrogels with Antifouling Properties As Membranes for Water Purification

Hydrogels have been widely utilized to enhance the surface hydrophilicity of membranes for water purification, increasing the antifouling properties and thus achieving stable water permeability through membranes over time. Here, we report a facile method to prepare hydrogels based on zwitterions for membrane applications. Freestanding films can be prepared from sulfobetaine methacrylate (SBMA) with a crosslinker of poly(ethylene glycol) diacrylate (PEGDA) via photopolymerization. The hydrogels can also be prepared by impregnation into hydrophobic porous supports to enhance the mechanical strength. These films can be characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) to determine the degree of conversion of the (meth)acrylate groups, using goniometers for hydrophilicity and differential scanning calorimetry (DSC) for polymer chain dynamics. We also report protocols to determine the water permeability in dead-end filtration systems and the effect of foulants (bovine serum albumin, BSA) on membrane performance.

This paper reports practical methods to prepare hydrogels in freestanding films and impregnated membranes and to characterize their physical properties, including water transport properties.

水凝胶的合成与防污性能作为膜的净水

Hydrogels have been widely utilized to enhance the surface hydrophilicity of membranes for water purification, increasing the antifouling properties and ...