我们感谢化学的麻省理工学院和麻省理工学院林肯实验室的高级概念委员会支持这项工作。

我们首先描述从3 kDa的O-（2 -氨基乙基）聚乙二醇（PEG-NH 2）和降冰片烯基-N-羟基琥珀酰亚胺（NHS）酯，PEG-MM B中的合成和纯化。前者化合物可自Sigma Aldrich公司购买，或根据文献方法22,23通过阴离子聚合制得。后者化合物可以在两个步骤中，根据已发布的程序21来制备。接下来，我们描述了从市售格拉布斯第二代催化剂的合成催化剂A的 。然后，我们演示了如何使用这个复杂的刷第一BASP合成。这个实验详细介绍了从BI带有DP = 10使BASPs与N = 10，15，和20。所有反应均在使用标准的闪烁瓶在通风橱进行。 注意:一定要戴手套，实验室外套，和实验室眼镜，以及与危险化学品工作时，遵循共同的实验室安全操作规范。任何有机溶剂必须在通风橱内进行处理。固体可以被测量出的通风橱以外的平衡。化学品不应该接触到皮肤，眼睛或口腔接触。强烈建议开始之前阅读的MSDS在此过程中每个溶剂和固体使用。 1。的PEG-MM B上下游<ol><li>添加PEG-NH 2（300毫克，0.0001摩尔，1.0当量）以40毫升闪烁小瓶中装有搅拌棒。 </li><li>溶解PEG-NH 2的3ml的无水N，N-二甲基甲酰胺（DMF）。 </li><li>加36毫克的降冰片烯-NHS酯（0.000105摩尔，1.05当量）21。 </li><li>盖上瓶盖，并搅拌过夜，反应混合物在室温下进行。 </li><li>取出搅拌棒，加入乙醚到反应溶液中以沉淀的PEG-MM 乙 。 </li><li>过滤白色流感FFY沉淀并用乙醚洗涤广泛。可替换地，该悬浮液转移至50μm的离心管中，离心分离机以4000 rpm离心5分钟，在室温下，再滗出上清液。再加入新鲜的乙醚，离心，倾倒。我们建议重复此步骤3次，总共5倍。 </li><li>在真空下干燥24小时的沉淀物以除去残余的二乙醚。 </li></ol> 2。的PEG-MM净化在我们以前的报告中，PEG-MM B的从市售PEG-NH 2的制备及用于合成的BASP未经进一步纯化干燥（ 即步1.7后）。在这个研究中，我们改变PEG-NH 2的源（商业与自制的），这样我们之前和之后更严格制备高效液相色谱（制备型HPLC）纯化的MM比较BASP形成的结果。在这项研究中，医生的其余部分步骤1.7之后获得IED MM被称为B1。制备型高效液相色谱用于纯化B1，得到B2。一个类似的制备型HPLC上纯化MM在我们通过阴离子聚合反应实验室合成被称为B3。制备型HPLC是使用贝克曼库尔特HPLC（127P溶剂模块和166p检测器模块）与1毫升样品环，在室温下安捷伦ZORBAX 300SB-C18 PrepHT端反相柱进行。 <ol><li>建立高效液相色谱用溶剂A:去离子水（Millipore公司的净化系统，18.2Ω）与1％乙酸，溶剂B:乙腈。 </li><li>总理泵和平衡柱用95％A和5％B。 </li><li>溶解PEG-MM在乙腈或甲醇（150毫克/毫升）。 </li><li>通过13mm的0.45微米尼龙注射器过滤器过滤。 </li><li>设置HPLC方法: - 流量:20毫升/分钟 - 0-1分钟:10％B和90％的线性梯度 - 1-10分钟:LINEAř梯度90％B和10％ - 10-13分钟:切换到初始条件（5％B和95％），并重新平衡柱 - 将UV检测器，以检测吸光度256 nm处</li><li>加载0.8毫升样品置于样品环。 </li><li>注入样品。 </li><li>收集的主要吸收峰（规定的条件下，该产品5-7分钟之间洗脱）。 </li><li>必要时重复。合并纯馏分一起在一个圆底烧瓶中。 </li><li>通过旋转蒸发除去所有的溶剂。 </li><li>再溶解的产物在二氯甲烷中，加入硫酸钠干燥。轻轻摇动或定期搅拌烧瓶≅1小时。 </li><li>用烧结玻璃过滤器过滤混合物。 </li><li>通过旋转蒸发浓缩。在真空下干燥过夜。 </li><li>的PEG-MM可以在光盘2的特征在于1 H-NMR Cl 2中 （15-20 mg/0.7毫升CD 2 Cl 2中 ，500 MHz或建议更高超过128扫描和弛豫延迟中，d1= 2.0秒），和MALDI-TOF使用正电离模式和2 - （4 - 羟基苯基偶氮）苯甲酸作为MALDI基质。 </li><li>的PEG-MM可以在4℃保存数月在闪烁瓶中</li></ol> 3。催化剂A的制备<ol><li>格拉布斯第二代催化剂（500毫克，0.589毫摩尔）加入20ml小瓶配有搅拌棒。 </li><li>加入吡啶（约0.474毫升，5.89毫摩尔，10当量）的小瓶。溶液的颜色应立即从红色变为绿色。使反应搅拌，直到所有的红颜色的消失，该溶液变得粘稠（15-30分钟）。 </li><li>填写反应小瓶用冷戊烷以沉淀复杂的一个 。 </li><li>过滤悬浮液收集绿色沉淀物（催化剂A）。 4倍洗净用15毫升冷戊烷。 </li><li>干燥绿色固体在真空下过夜。 </li><li>复杂的A可以是在室温下在台式干燥器存放数月无显著的活性损失。对于额外的预防措施，我们通常存储复杂的手套箱内的-20°C冰箱。为了方便，我们预先称重已知金额一成4毫升闪烁小瓶立即干燥（步骤3.5）后。然后，我们存储这些小瓶在手套箱冷冻。当准备运行一个ROMP反应，我们只是需要一小瓶出手套箱，并使用如下所述（步骤4.4）。 </li></ol> 4。的生活刷聚合物原液（BI）与准备DP = 10 <ol><li>在3具有气密螺丝帽配有搅拌棒毫升的小瓶中，掂量出MM 的B 65毫克（0.020毫摩尔，10当量）。这个量相当于20毫克的MM各3种不同尺寸BASPs的和5mg剩针对BI的GPC分析。用刮刀直接添加的MM到小瓶的底部。风帆y以防止材料粘附到小瓶的侧面，这种情况下可能会导致MM污染在最后BASP产物。 </li><li>溶解MM 的B 158微升的THF。加入THF，以避免溶剂挥发后，立即盖上瓶盖。注:MM的聚合过程中的最终浓度应为0.05米。若158微升THF中的此处添加，然后243微升的催化剂溶液，步骤4.4，将被添加到得到401微升THF总的，对应于[MM = 0.05 M的溶剂在该步骤中的量可以变化，只要溶剂在步骤4.4的量也各不相同，得到[MM] 0.05。我们发现，聚合反应进行了[MM] &lt;0.05有时不继续完成转换。 </li><li>让解决方案搅拌，直到所有的MM溶解。如果需要加热掉以轻心。避免飞溅的粘稠溶液到侧面或小瓶的帽。 </li><li>接下来，添加一个已知量（2.8毫克这个例子）催化剂A至3 ml小瓶（或获得与预先称重的催化剂A小瓶）的。添加无水THF（466微升在这个例子中），得到6毫克/毫升催化剂溶液。立即盖上瓶盖。使催化剂完全溶解;。如果需要轻轻摇动小瓶该催化剂溶液应立即使用ROMP。注1:该催化剂溶液应该是一个森林绿的颜色。如果是黑色或绿色，棕色，那么它有可能分解，它可能不会产生令人满意的ROMP的结果。如果发生分解，我们建议制备新鲜催化剂（根据上面第3部分），或者用新蒸馏的THF中。注2:添加到A中十二烷基硫酸钠的量被选择，以确保最终的[MM]为〜0.05。这一数额可以调整，只要补偿作出调整，在步骤4.2 MM的解决方案。 </li><li>加入243微升（1.46毫克; 1当量到B </强催化剂溶液&gt;）快速（未滴加）到搅拌的MM溶液。尝试添加到小瓶时保持针尖正上方的MM的解决方案。避免反应混合物喷溅到侧面和小瓶的盖子，如飞溅会导致在最终BASP残余MM和BI杂质。 </li><li>紧接在加盖的小瓶中，并让该反应混合物搅拌15分钟，以形成刷大分子引发剂（BI）。 </li></ol> 5。 BASPs的形成<ol><li>添加3.6±0.1毫克（6.18微摩尔，10当量到BI的步骤5.2要传输的量），5.5±0.1毫克（9.28μmol，15式到BI的步骤5.2要传输的量），和7.3± 0.1毫克（12.4μmol，20式到BI的被转移步骤5.2量）交联剂的C三个独立3毫升小瓶装有搅拌棒。试图直接称量交联剂到小瓶的底部，以防止材料粘附到所述小瓶的侧面。注:交联剂C不是在THF中高度可溶。出于这个原因，将固体直接用于此步。在情况下，交联剂是水溶性的，则交联剂的浓缩原液可与不同量的该溶液中可以转移到小瓶中。再次，在最后的聚合反应的浓度应&gt; 0.05 M;如果溶剂加入交联剂然后补偿性减少溶剂应在别处进行。 </li><li>新增的BI解决方案，每个含有C三个小瓶的123微升（0.618微摩尔）。尝试添加到小瓶时保持针尖正上方的固体交联剂。加入BI解决方案一次性全部而非溶液。 </li><li>盖上小瓶，搅拌反应在室温下，直到完成。与此特定的MM和交联剂的组合，反应完成后在〜4小时;继续搅拌达24小时，有对BASP生长没有明显的效果。通过GPC监测，以确保BI的完全转化。 </li><li>通过加入1滴乙基乙烯基醚，其余BI解决方案和每个的N = 10，15，和20 BASP反应混合物淬灭反应。搅拌10分钟，以确保完全猝灭。 </li></ol> 6。 GPC样品制备的GPC-MALLS测定的结果，得到在Agilent 1260 LC系统配备的Shodex GPC KD-806M柱，悦黎明HELEOS-II MALLS检测器，和一个悦的Optilab T-REX折射率检测器在室温下进行。 DMF与0.025M的溴化锂以1.0ml /分的流速分被用作洗脱剂。结果用惠悦公司提供的阿斯特拉6软件进行分析。 <ol><li>采用了全新的玻璃吸管每个反应瓶中，沾枪头到反应溶液中，以拟定反应的小样本。冲洗移液管的内部用250微升的0.025M的溴化锂在DMF中，得到大约3毫克/毫升的最终浓度。 </li><li>样品存入一个GPC小瓶前​​用0.45微米的聚四氟乙烯过滤器过滤稀释样品。 </li><li>建立GPC-MALLS测定的运行，一旦运行完成后分析结果。 </li></ol>缩略语表: 答 :格拉布斯第三代双吡啶催化剂 B:聚（乙二醇）（PEG）大分子单体（MM） B1:使用市售的（Aldrich）制备的PEG-NH 2和无HPLC纯化使用PEG MM制备。 B2:PEG MM使用市售的（Aldrich）制备的PEG-NH制备<sub&gt; 2和HPLC纯化后使用。 B3:用PEG MM制备新合成的PEG-NH 2和HPLC纯化后使用。 BASP:刷臂星形聚合物 BI:居住刷引发 C:光降解交联剂 D:摩尔质量分散度指数 DMF:N，N-二甲基甲酰胺 DP:数均聚合度 GPC:凝胶渗透色谱法制备型HPLC:制备性高效液相色谱法商场:多角度激光光散射 MM:大分子分子量:分子量 男女女:重均MO拉尔质量 否:数量交联剂等值（ 的C到A比） NHS:N-羟基 PEG:聚乙二醇 PEG-MM:降冰片烯的PEG大分子单体（也称为化合物B）的 ROMP:开环易位聚合 THF:四氢呋喃

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Symp. 293, 53-57 (2010).</li><li>Nomura, K., Watanabe, Y., Fujita, S., Fujiki, M., Otani, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Facile+Controlled+Synthesis+of+Soluble+Star+Shape+Polymers+by+Ring-Opening+Metathesis+Polymerization+(ROMP).">Facile Controlled Synthesis of Soluble Star Shape Polymers by Ring-Opening Metathesis Polymerization (ROMP).</a> Macromolecules. 42, 899-901 (2009).</li><li>Gao, H., Ohno, S., Matyjaszewski, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low+Polydispersity+Star+Polymers+via+Cross-Linking+Macromonomers+by+ATRP.">Low Polydispersity Star Polymers via Cross-Linking Macromonomers by ATRP.</a> J. Am. Chem. Soc. 128, 15111-15113 (2006).</li><li>Liu, J., Burts, A. O., Li, Y., Zhukhovitskiy, A. V., Ottaviani, M. F., Turro, N. J., Johnson, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term="Brush-First"+Method+for+the+Parallel+Synthesis+of+Photocleavable,+Nitroxide-Labeled+Poly(ethylene+glycol)+Star+Polymers.">"Brush-First" Method for the Parallel Synthesis of Photocleavable, Nitroxide-Labeled Poly(ethylene glycol) Star Polymers.</a> J. Am. Chem. Soc. 134, 16337-16344 (2012).</li><li>Studer, P., Larras, V., Riess, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amino+end-functionalized+poly(ethylene+oxide)-block-poly(methylidene+malonate+2.1.2)+block+copolymers:+synthesis,+characterization,+and+chemical+modification+for+targeting+purposes.">Amino end-functionalized poly(ethylene oxide)-block-poly(methylidene malonate 2.1.2) block copolymers: synthesis, characterization, and chemical modification for targeting purposes.</a> Eur. Polym. J. 44, 1714-1721 (2008).</li><li>Mosquet, M., Chevalier, Y., Le Perchec, P., Guicquero, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+poly+(ethylene+oxide)+with+a+terminal+amino+group+by+anionic+polymerization+of+ethylene+oxide+initiated+by+aminoalcoholates.">Synthesis of poly (ethylene oxide) with a terminal amino group by anionic polymerization of ethylene oxide initiated by aminoalcoholates.</a> Macromol. Chem. Phys. 198, 2457-2474 (1997).</li><li>Burchard, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solution+properties+of+branched+macromolecules.">Solution properties of branched macromolecules.</a> Adv. Polym. Sci. 143, 113-194 (1999).</li><li>Gao, H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+Star+Polymers+as+Unimolecular+Containers+for+Nanomaterials.">Development of Star Polymers as Unimolecular Containers for Nanomaterials.</a> Macromol. Rapid Comm. , 722-734 (2012).</li><li>Blencowe, A., Tan, J. F., Goh, T. K., Qiao, G. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Core+cross-linked+star+polymers+via+controlled+radical+polymerisation.">Core cross-linked star polymers via controlled radical polymerisation.</a> Polymer. 50, 5-32 (2009).</li><li>Burts, A. O., Liao, L., Lu, Y. Y., Tirrell, D. A., Johnson, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brush-first+and+Click:+Efficient+Synthesis+of+Nanoparticles+that+Degrade+and+Release+Doxorubicin+in+Response+to+Light.">Brush-first and Click: Efficient Synthesis of Nanoparticles that Degrade and Release Doxorubicin in Response to Light.</a> Photochem. Photobiol. , (2013).</li></ol>

作者什么都没有透露。

刷一BASP合成的关键优势是独特的能力，快速合成不同大小和组成的纳米结构并行而不需要专门的设备。在本研究中，我们证明了刷第一合成方法，使用降冰片烯官能化的PEG大分子单体（B，图1）和一个双-降冰片烯硝基苄酯交联剂（C，图1）。从B中的PEG链赋予水溶性的最终BASP结构。对硝基苄基交联剂是光降解。 这是一...

纳米粒子的聚合物已被广泛研究其作为平台用于药物递送，支持催化，生物成像，并自组装1-3的潜在用途。现代应用要求纳米粒子合成是轻便，重现性好，化学功能兼容，并服从多样化4,5。应变烯烃的开环复分解聚合（ROMP）是一个功能强大的方法论的官能聚合物的纳米结构具有受控尺寸和窄的质量分布1,6〜8的合成。例如，降冰片烯官能化的聚（乙二醇）（PEG）大分子单体（MMS）可以有效地通过ROMP聚合生成水溶性的瓶刷聚合物。使用这种方法，即携带多个可释放的药物分子，荧光团，和自旋造影剂的纳米结构可迅速地并在平行6，9，10制备。 只读存储器磷已也被用于"臂先"合成星形聚合物。在臂先法，线性聚合物是交联的多官能交联剂，得到球形纳米结构聚合物臂。施罗克和同事报道了第一臂先ROMP合成星形聚合物的通过降冰片烯，dicarbomethoxynorbornadiene，并与双官能交联剂的降冰片烯三甲基甲硅烷保护的dicarboxynorbornene线性聚合物的交联。11,12 Buchmeiser已扩展这种方法对材料的合成与的应用范围，其中包括支持催化，组织工程和层析13-17。大谷和他的同事已经通过相关的"输入-输出"聚合战略18，19做星形聚合物纳米粒子与功能性的表面。 大多数臂先聚合涉及单体，聚合物和明星偶联反应之间复杂的相互作用。钍通过这通常会导致较宽的分子量（MW）的分布逐步增长机构E后者的收益。为了克服这一限制在相关臂先原子转移自由基聚合反应，Matyjaszewski等人进行的预制聚合物的MM臂先交联，以提供星形聚合物具有非常窄的分子量分布20。在这种情况下，空间体积的MM中，和星武器的比例增加至起始位点，抑制控制不佳星+星型连接器的进程，并导致为生，环比增长机制。 当我们试图在同一策略中ROMP的具有降冰片烯封端的PEG-MM和一个双 - 降冰片烯的交联剂的情况下，星形聚合物具有非常广泛的，多模态分子量分布得到。这一结果表明，在该系统中，单独的MM不够笨重抑制星形+星形耦合。为了增加空间体积的明星武器，并有可能限制这种uncontroLLED耦合，我们试图先聚合的MM，形成瓶刷聚合物，在没有交联剂，然后加入交联剂。我们很高兴地发现，在一定条件下，这种"刷第一"的方法提供了简单的访问"刷臂星形聚合物"（BASPs）与窄分子量分布和可调谐的核心和电晕功能。 最近，我们报道了刷第一ROMP合成使用格拉布斯第三代催化剂A（图1）21 PEG BASPs的。在这项工作中，PEG-MM B暴露催化剂 A产生的生活刷大分子引发剂与定义的骨架长度（B 1，图1）。 乙 1等分转移到含有不同量的交联剂的C小瓶启动BASP形成。的分子量，并且BASPs的，因此大小，几何形状增加了用C的添加量。我们提供了一种机理假设对于此几何级数增长过程，并证明功能性，氮氧化物芯和电晕标记BASPs可以容易，而不需要后聚合改性的步骤或顺序添加单体制备。然而，在所有的报道的例子中，我们关注的催化剂失活，我们进行了手套箱内氮气气氛下，所有的反应。 由于我们的初步报告中，我们发现，刷第一种方法是非常有效的从广泛的降冰片烯终止彩信和功能交联剂形成BASPs的。我们还发现，该方法可以在台式执行没有特殊的预防措施，以除去空气或水分。 此处，一系列不同分子量和脱乙酰三BASPs将SY通过刷子先法在环境条件下nthesized。简言之，10当量乙的将被暴露在15分钟1.0当量的催化剂A（图1a），以产生一个BI与平均聚合度为10（DP）。三等分这批商业智能的将被转移的C 20 的当量（N， 图1b），以含有10，15分开的小瓶，和。 4小时后，聚合反应将通过添加乙基乙烯基醚淬灭。星形聚合物兆瓦和分子量分布将使用凝胶渗透色谱仪配备有一个多角度激光光散射检测器（GPC-MALLS）进行表征。

<table border="0" cellpadding="0" cellspacing="0" width="592">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="42">
			<td height="84" rowspan="2" style="height:84px;width:216px;">Grubbs Second Generation Catalyst</td>
			<td rowspan="2" style="width:91px;">Materia (or Sigma Aldrich)</td>
			<td rowspan="2" style="width:119px;">C848 (Sigma Aldrich: 569747)</td>
			<td style="width:167px;">
			Used as purchased from manufacturer. 
 *Provided as a generous gift.
			</td>
		</tr>
		<tr height="42">
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Pyridine</td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td style="width:119px;">270970</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">O-(2-aminoethyl)polyethylene glycol 3000</td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td style="width:119px;">07969</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">PEG-MM</td>
			<td style="width:91px;">N/A</td>
			<td style="width:119px;">N/A</td>
			<td style="width:167px;">Synthesized following reported procedures (Ref. 21, protocol 1)</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">norbornene-N-hydroxysuccinimidyl (NHS) ester</td>
			<td style="width:91px;">N/A</td>
			<td style="width:119px;">N/A</td>
			<td style="width:167px;">Synthesized following reported procedures (Ref. 21)</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Bis-norb-NBOC Crosslinker</td>
			<td style="width:91px;">N/A</td>
			<td style="width:119px;">N/A</td>
			<td style="width:167px;">Synthesized following reported procedures (Ref. 21)</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Pentane</td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td style="width:119px;">158941</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Tetrahydrofuran (HPLC grade)</td>
			<td style="width:91px;">Sigma Aldrich </td>
			<td style="width:119px;">34865</td>
			<td style="width:167px;">Dried and purified over a solvent purification columns </td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Dichloromethane</td>
			<td style="width:91px;">VWR </td>
			<td>BDH1113-4LG</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Acetonitrile (HPLC grade)</td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td style="width:119px;">34998</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Acetic Acid </td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td style="width:119px;">A6283</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Sodium sulfate </td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td>239313</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Diethyl ether</td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td style="width:119px;">673811</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Dimethylformamide (HPLC grade) </td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td style="width:119px;">270547</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Lithium Bromide</td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td style="width:119px;">213225</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">MillQ Biocel A10</td>
			<td style="width:91px;">Millipore</td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Beckmann Coulter HPLC (127p solvent module, 166p detector)</td>
			<td style="width:91px;">Beckmann Coulter</td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Zorbax 300SB-C18 PrepHT reverse phase column </td>
			<td style="width:91px;">Agilent</td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">1260 Infinity Liquid Chromatography </td>
			<td style="width:91px;">Agilent</td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">GPC KD-806M column</td>
			<td style="width:91px;">Shodex</td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Dawn Heleos II Light Scatterer</td>
			<td style="width:91px;">Wyatt</td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Optilab T-rEX Refractive Index Detector</td>
			<td style="width:91px;">Wyatt</td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Glass Scintillation Vials - 40 ml</td>
			<td style="width:91px;">Chemglass</td>
			<td>CG-4909-05</td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Glass Scintillation Vials - 4 ml </td>
			<td style="width:91px;">Chemglass</td>
			<td style="width:119px;">CG-4904-06</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Glass Scintillation Vials (PTFE-lined cap) - 2 ml </td>
			<td style="width:91px;">Agilent</td>
			<td>5183-4518</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Stir-bars</td>
			<td style="width:91px;">VWR</td>
			<td style="width:119px;">5894x</td>
			<td style="width:167px;">various sizes </td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">13 mm 0.45 &#181;m Nylon Syringe filter</td>
			<td style="width:91px;">PerkinElmer</td>
			<td>02542903</td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">13 mm 0.45 &#181;m polytetrafluoroethylene syringe filter</td>
			<td style="width:91px;">PerkinElmer</td>
			<td>02542909</td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">1 ml disposable syringes </td>
			<td style="width:91px;">VWR</td>
			<td style="width:119px;">53548-001</td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Swing bucket centrifuge or similar</td>
			<td style="width:91px;"> </td>
			<td style="width:119px;"> </td>
			<td style="width:167px;">Should be able to reach approximately 4,000 rpm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Round bottom flask</td>
			<td style="width:91px;"> </td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Fritted glass filter assembly </td>
			<td style="width:91px;"> </td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Rotary Evaporator </td>
			<td style="width:91px;"> </td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Balance </td>
			<td style="width:91px;"> </td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
	</tbody>
</table>

particles without a box: brush-first synthesis of photodegradable peg star polymers under ambient conditions

便利的方法多样功能化纳米粒子的快速，平行合成，使发现新配方的药物释放，生物成像，并支持催化作用。在这份报告中，我们展示了刷臂星形聚合物（BASP）纳米粒子的"刷第一"的方法平行合成。在该方法中，降冰片烯封端的聚（乙二醇）（PEG）大分子单体（PEG-MM）通过开环易位聚合反应（ROMP）的第一聚合以生成一个活刷大分子引发剂。这引发剂原液等分试样加入到含有不同量的光分解双降冰片烯交联剂的小瓶。暴露在交联剂引发了一系列动力学控制刷+刷和明星+明星偶合反应，最终产生BASPs与内核由聚乙二醇组成的交联剂和电晕的。最终BASP大小取决于交联剂的添加量。我们开展同步论文对没有特殊的预防措施以消除空气和水分的台式3 BASPs。该样品的特征在于用凝胶渗透色谱（GPC）;结果密切同意与我们以前的灵活运用惰性（手套箱）条件的报告。关键的实际特征，优点和刷第一方法的潜在缺点进行了讨论。

图2示出的GPC迹线用于各种从B1，B2和B3制备BASPs的。在所有情况下，该数据表明，增加交联剂（N）的当量导致增加的BASP的大小。由于观察到在我们以前的报告中，10当量的交联剂是不足以实现统一BASPs;在N = 10的样品显示了一个清楚的多模态跟踪的GPC用大量残留聚合物刷，特别是在未纯化的MM B1的情况下（ 图2...

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Particles without a Box: Brush-first Synthesis of Photodegradable PEG Star Polymers under Ambient Conditions

聚（乙二醇）（PEG）的电刷臂的星形聚合物（BASPs）与窄质量分布及可调谐纳米级的大小是通过PEG-降冰片烯大分子单体随后将得到的生活的各部分的传递的开环易位聚合（ROMP）合成刷引发剂含有不同量的刚性，光可切割双降冰片烯交联剂的小瓶。

颗粒无箱:可光降解的PEG星形聚合物在环境条件刷第一个合成

Convenient methods for the rapid, parallel synthesis of diversely functionalized nanoparticles will enable discovery of novel formulations for drug ...

particles-without-box-brush-first-synthesis-photodegradable-peg-star

Universidad de Cartagena UDEC

Research

JoVE Journal

Chemistry

39.6K 次观看.  Massachusetts Institute of Technology. 聚（乙二醇）（PEG）的电刷臂的星形聚合物（BASPs）与窄质量分布及可调谐纳米级的大小是通过PEG-降冰片烯大分子单体随后将得到的生活的各部分的传递的开环易位聚合（ROMP）合成刷引发剂含有不同量的刚性，光可切割双降冰片烯交联剂的小瓶。 

视频: Particles without a Box: Brush-first Synthesis of Photodegradable PEG Star Polymers under Ambient Conditions

A Simple Method for the Size Controlled Synthesis of Stable Oligomeric Clusters of Gold Nanoparticles under Ambient Conditions

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like oligomeric clusters of these yellow nanoparticles of narrow size distribution are synthesized under ambient conditions via two methods. The delay-time method controls the number of subunits in the oligoclusters by varying the time between the addition of HAuCl4 to alkaline solution and the subsequent addition of reducing agent, NaSCN. The yellow oligoclusters produced range in size from ~3 to ~25 nm. This size range can be further extended by an add-on method utilizing hydroxylated gold chloride (Na+[Au(OH4-x)Clx]-) to auto-catalytically increase the number of subunits in the as-synthesized oligocluster nanoparticles, providing a total range of 3 nm to 70 nm. The crude oligocluster preparations display narrow size distributions and do not require further fractionation for most purposes. The oligoclusters formed can be concentrated &#62;300 fold without aggregation and the crude reaction mixtures remain stable for weeks without further processing. Because these oligomeric clusters can be concentrated before derivatization they allow expensive derivatizing agents to be used economically. In addition, we present two models by which predictions of particle size can be made with great accuracy.

We describe a simple method for producing highly stable oligomeric clusters of gold nanoparticles via the reduction of chloroauric acid (HAuCl4) with sodium thiocyanate (NaSCN). The oligoclusters have a narrow size distribution and can be produced with a wide range of sizes and surface coats.

根据环境条件的金纳米粒子的稳定低聚簇的大小控制合成的一种简便方法

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like ...

科研

化学

Visualization of Ambient Mass Spectrometry with the Use of Schlieren Photography

This manuscript outlines how to visualize mass spectrometry ambient ionization sources using schlieren photography. In order to properly optimize the mass spectrometer, it is necessary to characterize and understand the physical principles of the source. Most commercial ambient ionization sources utilize jets of nitrogen, helium, or atmospheric air to facilitate the ionization of the analyte. As a consequence, schlieren photography can be used to visualize the gas streams by exploiting the differences in refractive index between the streams and ambient air for visualization in real time. The basic setup requires a camera, mirror, flashlight, and razor blade. When properly configured, a real time image of the source is observed by watching its reflection. This allows for insight into the mechanism of action in the source, and pathways to its optimization can be elucidated. Light is shed on an otherwise invisible situation.

This paper presents a protocol for the visualization of gaseous streams of an ambient ionization source using schlieren photography and mass spectrometry.

环境质谱可视化纹影摄影的使用

This manuscript outlines how to visualize mass spectrometry ambient ionization sources using schlieren photography. In order to properly optimize the mass ...

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single molecule level. An electrostatic self-assembly and covalent fixation (ESA-CF) process is used for the synthesis of the cyclic poly(tetrahydrofuran) (poly(THF)). The diffusive motion of individual cyclic polymer chains in a melt state is visualized using single molecule fluorescence imaging by incorporating a fluorophore unit in the cyclic chains. The diffusive motion of the chains is quantitatively characterized by means of a combination of mean-squared displacement (MSD) analysis and a cumulative distribution function (CDF) analysis. The cyclic polymer exhibits multiple-mode diffusion which is distinct from its linear counterpart. The results demonstrate that the diffusional heterogeneity of polymers that is often hidden behind ensemble averaging can be revealed by the efficient synthesis of the cyclic polymers using the ESA-CF process and the quantitative analysis of the diffusive motion at the single molecule level using the MSD and CDF analyses.

A protocol for the synthesis and characterization of diffusive motion of cyclic polymers at the single molecule level is presented.

环状聚合物的合成及其在熔融状态扩散运动的表征在单分子水平

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single ...

Facile Preparation of Ultrafine Aluminum Hydroxide Particles with or without Mesoporous MCM-41 in Ambient Environments

An aqueous suspension of nanogibbsite was synthesized via the titration of aluminum aqua acid [Al(H2O)6]3+ with L-arginine to pH 4.6. Since the hydrolysis of aqueous aluminum salts is known to produce a wide array of products with a wide range of size distributions, a variety of state-of-the-art instruments (i.e., 27Al/1H NMR, FTIR, ICP-OES, TEM-EDX, XPS, XRD, and BET) were used to characterize the synthesis products and identification of byproducts. The product, which was comprised of nanoparticles (10-30 nm), was isolated using gel permeation chromatography (GPC) column technique. Fourier transform infrared (FTIR) spectroscopy and powder X-ray diffraction (PXRD) identified the purified material as the gibbsite polymorph of aluminum hydroxide. The addition of inorganic salts (e.g., NaCl) induced electrostatic destabilization of the suspension, thereby agglomerating the nanoparticles to yield Al(OH)3 precipitate with large particle sizes. By utilizing the novel synthetic method described here, Al(OH)3 was partially loaded inside the highly ordered mesoporous framework of MCM-41, with average pore dimensions of 2.7 nm, producing an aluminosilicate material with both octahedral and tetrahedral Al (Oh/Td = 1.4). The total Al content, measured using energy-dispersive X-ray spectrometry (EDX), was 11% w/w with a Si/Al molar ratio of 2.9. A comparison of bulk EDX with surface X-ray photoelectron spectroscopy (XPS) elemental analysis provided insight into the distribution of Al within the aluminosilicate material. Furthermore, a higher ratio of Si/Al was observed on the external surface (3.6) as compared to the bulk (2.9). Approximations of O/Al ratios suggest a higher concentration of Al(O)3 and Al(O)4 groups near the core and external surface, respectively. The newly developed synthesis of Al-MCM-41 yields a relatively high Al content while maintaining the integrity of the ordered silica framework and can be used for applications where hydrated or anhydrous Al2O3 nanoparticles are advantageous.

An ultrafine aluminum hydroxide nanoparticle suspension was prepared via the controlled titration of [Al(H2O)]3+ with L-arginine to pH 4.6 with and without cage-effect confinement within mesoporous channels of MCM-41.

在环境环境中制备具有或不具有介孔MCM-41的超细氢氧化铝颗粒

An aqueous suspension of nanogibbsite was synthesized via the titration of aluminum aqua acid [Al(H2O)6]3+ with L-arginine to pH 4.6. Since the hydrolysis ...

Facet-to-facet Linking of Shape-anisotropic Colloidal Cadmium Chalcogenide Nanostructures

Here, we describe a protocol that allows for shape-anisotropic cadmium chalcogenide nanocrystals (NCs), such as nanorods (NRs) and tetrapods (TPs), to be covalently and site-specifically linked via their end facets, resulting in polymer-like linear or branched chains. The linking procedure begins with a cation-exchange process in which the end facets of the cadmium chalcogenide NCs are first converted to silver chalcogenide. This is followed by the selective removal of ligands at their surface. This results in cadmium chalcogenide NCs with highly reactive silver chalcogenide end facets that spontaneously fuse upon contact with each other, thereby establishing an interparticle facet-to-facet attachment. Through the judicious choice of precursor concentrations, an extensive network of linked NCs can be produced. Structural characterization of the linked NCs is carried out via low- and high-resolution transmission electron microscopy (TEM), as well as energy-dispersive X-ray spectroscopy, which confirm the presence of silver chalcogenide domains between chains of cadmium chalcogenide NCs.

A protocol detailing how shape-anisotropic colloidal cadmium chalcogenide nanocrystals can be covalently linked via their end facets is presented here.

形状-各向异性胶体镉硫纳米结构的 Facet-to-facet 连接

Here, we describe a protocol that allows for shape-anisotropic cadmium chalcogenide nanocrystals (NCs), such as nanorods (NRs) and tetrapods (TPs), to be ...

Phase Behavior of Charged Vesicles Under Symmetric and Asymmetric Solution Conditions Monitored with Fluorescence Microscopy

Phase-separated giant unilamellar vesicles (GUVs) exhibiting coexisting liquid-ordered and liquid-disordered domains are a common biophysical tool to investigate the lipid raft hypothesis. Numerous studies, however, neglect the impact of physiological solution conditions. On that account, the current work presents the effect of high-salinity buffer and trans-membrane solution asymmetry on liquid-liquid phase separation in charged GUVs grown from dioleylphosphatidylglycerol, egg sphingomyelin, and cholesterol. The effects were studied under isothermal and varying temperature conditions.
We describe equipment and experimental strategies applicable for monitoring the stability of coexisting liquid domains in charged vesicles under symmetric and asymmetric high-salinity solution conditions. This includes an approach to prepare charged multicomponent GUVs in high-salinity buffer at high temperatures. The protocol entails the option to perform a partial exchange of the external solution by a simple dilution step while minimizing the vesicle dilution. An alternative approach is presented utilizing a microfluidic device that allows for a complete external solution exchange. The solution effects on phase separation were also studied under varying temperatures. To this end, we present the basic design and utility of an in-house built temperature control chamber. Furthermore, we reflect on the assessment of the GUV phase state, pitfalls associated with it and how to circumvent them.

Experiments on phase separated giant unilamellar vesicles (GUVs) frequently neglect physiological solution conditions. This work presents approaches to study the effect of high-salinity buffer on liquid-liquid phase separation in charged multicomponent GUVs as a function of trans-membrane solution asymmetry and temperature.

用荧光显微镜监测对称和非对称溶液条件下带电泡的相行为

Phase-separated giant unilamellar vesicles (GUVs) exhibiting coexisting liquid-ordered and liquid-disordered domains are a common biophysical tool to ...

Synthesis of Core-shell Lanthanide-doped Upconversion Nanocrystals for Cellular Applications

Lanthanide-doped upconversion nanocrystals (UCNs) have attracted much attention in recent years based on their promising and controllable optical properties, which allow for the absorption of near-infrared (NIR) light and can subsequently convert it into multiplexed emissions that span over a broad range of regions from the UV to the visible to the NIR. This article presents detailed experimental procedures for high-temperature co-precipitation synthesis of core-shell UCNs that incorporate different lanthanide ions into nanocrystals for efficiently converting deep-tissue penetrable NIR excitation (808 nm) into a strong blue emission at 480 nm. By controlling the surface modification with biocompatible polymer (polyacrylic acid, PAA), the as-prepared UCNs acquires great solubility in buffer solutions. The hydrophilic nanocrystals are further functionalized with specific ligands (dibenzyl cyclooctyne, DBCO) for localization on the cell membrane. Upon NIR light (808 nm) irradiation, the upconverted blue emission can effectively activate the light-gated channel protein on the cell membrane and specifically regulate the cation (e.g., Ca2+) influx in the cytoplasm. This protocol provides a feasible methodology for the synthesis of core-shell lanthanide-doped UCNs and subsequent biocompatible surface modification for further cellular applications.

A protocol is presented for the synthesis of core-shell lanthanide-doped upconversion nanocrystals (UCNs) and their cellular applications for channel protein regulation upon near-infrared (NIR) light illumination.

核壳镧系掺杂转换纳米晶的合成及其在蜂窝中的应用

Lanthanide-doped upconversion nanocrystals (UCNs) have attracted much attention in recent years based on their promising and controllable optical ...

Solid-phase Synthesis of [4.4] Spirocyclic Oximes

A convenient synthetic route for spirocyclic heterocycles is well sought after due to the molecule&#39;s potential use in biological systems. By means of solid-phase synthesis, regenerating Michael (REM) linker strategies, and 1,3-dipolar cycloaddition, a library of structurally similar heterocycles, both with and without a spirocyclic center, can be constructed. The main advantages of the solid-support synthesis are as follows: first, each reaction step can be driven to completion using a large excess of reagents resulting in high yields; next, the use of commercially available starting materials and reagents keep the costs low; finally, the reaction steps are easy to purify via simple filtration. The REM linker strategy is attractive because of its recyclability and traceless nature. Once a reaction scheme is completed, the linker can be reused multiple times. In a typical solid-phase synthesis, the product contains either a part of or the whole linker, which can prove undesirable. The REM linker is &#34;traceless&#34; and the point of attachment between the product and the polymer is indistinguishable. The high diastereoselectivity of the intramolecular 1,3-dipolar cycloaddition is well documented. Limited by the insolubility of the solid support, the reaction progression can only be monitored by a change in the functional groups (if any) via infrared (IR) spectroscopy. Thus, the structural identification of intermediates cannot be characterized by conventional nuclear magnetic resonance (NMR) spectroscopy. Other limitations to this method stem from the compatibilities of the polymer/linker to the desired chemical reaction scheme. Herein we report a protocol that allows for the convenient production of spirocyclic heterocycles that, with simple modifications, can be automated with high-throughput techniques.

Here we present a protocol to demonstrate an efficient method for the synthesis of spirocyclic heterocycles. The five-step process utilizes solid-phase synthesis and regenerating Michael linker strategies. Generally difficult to synthesize, we present a customizable method for the synthesis of spirocyclic molecules otherwise inaccessible to other modern approaches.

[4.4] 刺环氧基的固相合成

A convenient synthetic route for spirocyclic heterocycles is well sought after due to the molecule&#39;s potential use in biological systems. By means of ...

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

The interest on nitrogen-containing heterocycles has expanded rapidly in the synthetic community since they are important motifs for new drugs. Traditionally, they were synthesized through thermal cycloaddition reactions, whereas today, photocatalysis is preferred due to the mild and efficient conditions. With this focus, a new photocatalytic method for the synthesis of nitrogen-containing heterocycles is highly desired. Here, we report a protocol for the biosynthesis of cercosporin, which could function as a metal-free photocatalyst. We then illustrate cercosporin-photocatalyzed protocols for the synthesis of nitrogen-containing heterocycles 1,2,3-thiadiazoles through annulation of azoalkenes with KSCN, and synthesis of 1,4,5,6-tetrahydropyridazines [4+2] through cyclodimerization of azoalkenes under mild conditions, respectively. As a result, there is a new bridge between the microbial fermentation method and organic synthesis in a mild, cost-effective, environmentally friendly and sustainable manner.

New routes for the synthesis of nitrogen-containing heterocycles utilizing cercosporin as a metal-free photocatalyst were developed.

神经素-光催化 [4]1]- 和 [4]2]- 在轻度条件下对阿佐尔克内斯的无效

The interest on nitrogen-containing heterocycles has expanded rapidly in the synthetic community since they are important motifs for new drugs. ...

A Femtoliter Droplet Array for Massively Parallel Protein Synthesis from Single DNA Molecules

Advances in spatial resolution and detection sensitivity of scientific instrumentation make it possible to apply small reactors for biological and chemical research. To meet the demand for high-performance microreactors, we developed a femtoliter droplet array (FemDA) device and exemplified its application in massively parallel cell-free protein synthesis (CFPS) reactions. Over one million uniform droplets were readily generated within a finger-sized area using a two-step oil-sealing protocol. Every droplet was anchored in a femtoliter microchamber composed of a hydrophilic bottom and a hydrophobic sidewall. The hybrid hydrophilic-in-hydrophobic structure and the dedicated sealing oils and surfactants are crucial for stably retaining the femtoliter aqueous solution in the femtoliter space without evaporation loss. The femtoliter configuration and the simple structure of the FemDA device allowed minimal reagent consumption. The uniform dimension of the droplet reactors made large-scale quantitative and time-course measurements convincing and reliable. The FemDA technology correlated the protein yield of the CFPS reaction with the number of DNA molecules in each droplet. We streamlined the procedures about the microfabrication of the device, the formation of the femtoliter droplets, and the acquisition and analysis of the microscopic image data. The detailed protocol with the optimized low running cost makes the FemDA technology accessible to everyone who has standard cleanroom facilities and a conventional fluorescence microscope in their own place.

The overall goal of the protocol is to prepare over one million ordered, uniform, stable, and biocompatible femtoliter droplets on a 1 cm2 planar substrate that can be used for cell-free protein synthesis.