这项研究是由里斯家庭创新奖和美国国立卫生研究院1R01NR015674-01到MK支持。作者感谢何塞普Nayfach（Qteris公司）提供的电磁发电机系统，以及他的技术咨询。作者还感谢焕颜（LCI及物理化学跨学科计划，肯特州立大学），她的技术助理。

注意: 在图1A中示出的制造磁场响应明胶微凝胶的整个过程。 1.准备解决方案及停牌<ol><li>通过在2ml磷酸盐缓冲盐水中溶解20mg的京尼平的制备交联剂京尼平（1％重量/体积）溶液（1×PBS; pH 7.4）中。涡旋该溶液，并发生在50℃水浴2小时以完全溶解该溶液中。 </li><li>由20毫克聚（乙二醇）的聚（丙二醇） -聚（乙二醇）溶解制备表面活性剂溶液（M W = 2900达;称为L64）在200毫升PBS中是在100的浓度PPM。 </li><li>由64.5毫克明胶溶于0.43毫升的PBS制备15％（重量/体积）明胶溶液。涡旋该溶液，将其放在水浴在37℃下 ，直到它到达一个溶胶相，其中所述溶液变成流体。然后，涡明胶溶液2 - 3次，以确保日样品电子同质性。 </li><li> P（NIPAM- 共 -AAm）/的MNP溶液与模型药物（BSA）的制备: <ol><li>分散10.75毫克亲水的MNP的0.43毫升的PBS，然后在MNP悬浮液溶解12.9毫克对的（NIPAM- 共同 -AAm），使其浓度为3％（重量/体积）。的p（NIPAM- 共同 -AAm）浓度的增加，可用于实现微凝胶的增加的消溶胀行为。 </li><li>使用得克萨斯州红共轭牛血清白蛋白（TR-BSA; 男女〜66 kDa的）为模型药物。溶解0.5毫克的TR-BSA中的p（NIPAM- 共同 -AAm）/的MNP的混合物。 </li></ol></li><li>通过增加（0.43毫升）P（NIPAM- 合作 -AAm）混合/的MNP（0.43毫升）到明胶溶液，然后准备明胶/ P（NIPAM- 合作 -AAm）/的MNP / BSA溶液（0.86毫升）的混合物彻底涡他们作出均匀的混合物。因此，聚合物和MNP的浓度成为初始浓度在最终混合物的一半。 </li></ol><ol><li>倒入15毫升硅油[聚二甲基硅氧烷（粘度350 CST）]成一个洁净无菌烧杯中。 </li><li>立即加入明胶/ P（NIPAM- 共 -AAm）/的MNP / BSA溶液（0.86毫升）的预先准备好的含水混合物进硅油，并通过与在900磁性搅拌棒搅拌下乳化于油相中的含水混合物转速，在30℃下 30分钟。 </li></ol> 3.凝胶和微滴转移到水溶液<ol><li>传送从烧杯乳液（〜16ml）中到50毫升管中。 </li><li>冷却该管10分钟，在4℃下，在油中的微滴的凝胶化。 </li><li>装满准备L64溶液（4℃）管可达50 ml和大力摇晃管。它可以是可能的的L64表面活性剂的一部分将是微凝胶内。 </li><li>离心管20分钟为2300 XG在4℃ </li><li> Regularlý检查凝胶粒子的颗粒在管的一侧的存在。如果颗粒不可见，离心以相同的速度和温度20分钟。请继续小心地取出上清液，而不会干扰形成在管的内壁上的沉淀。 </li><li>重复步骤（3.3）至（3.5）一次。每次，将样品转移到新的试管中，以避免任何油滴中微粒凝胶悬浮液中的夹杂物。此步骤后，确保表面活性剂或油滴中不存在的样品悬浮液。然而，重复的分离步骤可导致初始材料的损失。 </li></ol> 4.微凝胶的共价交联<ol><li>加2ml的京尼平溶液（在第1制备的），以凝胶粒子的沉淀并通过涡旋将溶液它们拌匀。 </li><li>很快，在23℃下转移在水浴将悬浮液的管中的德期间发起的共价交联反应（ 如5 - 120分钟）IRED交联时间。 </li><li>交联后，立即被丢弃京尼平的解决方案，在PBS重悬微凝胶，和2,300 XG（4℃）离心管20分钟，除去任何过多的交联剂。如果需要的话，小心翼翼掰开形成颗粒用枪头。该洗涤步骤可重复最多3次，如果京尼平仍然在溶液中剩下的。 </li><li>通过用血球计数的数目弃去上清液并以所希望的密度重悬在PBS中的微粒凝胶（例如，5×10 6微凝胶/ ml）中。 </li><li>对于显微镜观察，加载微粒凝胶悬浮液在载玻片和盖玻片之间的空间和密封用环氧树脂盖玻片的边界。 </li></ol>触发药物释放交变磁场5.应用<ol><li>放置管与在水性介质中微凝胶的期望浓度成磁线圈的腔室。如果需要的话，插入一个光纤温度探头插入管的AMF的应用过程中监视介质的温度变化。 </li><li>在限定的场强（&gt; 5千安/米）和一特定的持续时间施加高频率（&gt; 100千赫）的AMF。以下的AMF的应用，离心机在2,273 xg离心（4℃）并收集上清液量化从微粒凝胶释放到使用分光周围介质的TR-BSA的量20分钟的样品管中。为德克萨斯红的激发和发射波长分别为584纳米和612纳米。 </li></ol>

<ol>
	<li>Langer, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomaterials+in+drug+delivery+and+tissue+engineering:+one+laboratory's+experience.">Biomaterials in drug delivery and tissue engineering: one laboratory's experience.</a> Acc. Chem. Res. 33, 94-101 (2000).</li><li>Rivest, C. M., Morrison, D., Ni, B., Rubib, J., Yadav, V., Mahdavi, A., Karp, J., Khademhosseini, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microscale+hydrogels+for+medicine+and+biology:+synthesis,+characteristics+and+applications.">Microscale hydrogels for medicine and biology: synthesis, characteristics and applications.</a> J Mech Mater Struct. 2, 1103-1119 (2007).</li><li>Kawaguchi, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermoresponsive+microhydrogels:+preparation,+properties+and+applications.">Thermoresponsive microhydrogels: preparation, properties and applications.</a> Polym. Int. 63, 925-932 (2014).</li><li>Vinogradov, S. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Colloidal+microgels+in+drug+delivery+applications.">Colloidal microgels in drug delivery applications.</a> Curr. Pharm. Des. 12, 4703-4712 (2006).</li><li>Liechty, W. B., Kryscio, D. R., Slaughter, B. V., Peppas, N. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymers+for+drug+delivery+systems.">Polymers for drug delivery systems.</a> Annu Rev Chem Biomol Eng. 1, 149-173 (2010).</li><li>Kumari, A., Yadav, S. K., Yadav, S. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biodegradable+polymeric+nanoparticles+based+drug+delivery+systems.">Biodegradable polymeric nanoparticles based drug delivery systems.</a> Colloids Surf. B Biointerfaces. 75, 1-18 (2010).</li><li>Shibayama, M., Tanaka, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Volume+Phase-Transition+and+Related+Phenomena+of+Polymer+Gels.">Volume Phase-Transition and Related Phenomena of Polymer Gels.</a> Adv Polym Sci. 109, 1-62 (1993).</li><li>Sung, B., Kim, C., Kim, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biodegradable+colloidal+microgels+with+tunable+thermosensitive+volume+phase+transitions+for+controllable+drug+delivery.">Biodegradable colloidal microgels with tunable thermosensitive volume phase transitions for controllable drug delivery.</a> J Colloid Interface Sci. 450, 26-33 (2015).</li><li>Kumar, C. S., Mohammad, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Magnetic+nanomaterials+for+hyperthermia-based+therapy+and+controlled+drug+delivery.">Magnetic nanomaterials for hyperthermia-based therapy and controlled drug delivery.</a> Adv. Drug Deliv. Rev. 63, 789-808 (2011).</li><li>Mura, S., Nicolas, J., Couvreur, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stimuli-responsive+nanocarriers+for+drug+delivery.">Stimuli-responsive nanocarriers for drug delivery.</a> Nat. Mater. 12, 991-1003 (2013).</li><li>Kong, S. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Magnetic+field+activated+lipid-polymer+hybrid+nanoparticles+for+stimuli-responsive+drug+release.">Magnetic field activated lipid-polymer hybrid nanoparticles for stimuli-responsive drug release.</a> Acta biomaterialia. 9, 5447-5452 (2013).</li><li>Hayashi, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Magnetically+responsive+smart+nanoparticles+for+cancer+treatment+with+a+combination+of+magnetic+hyperthermia+and+remote-control+drug+release.">Magnetically responsive smart nanoparticles for cancer treatment with a combination of magnetic hyperthermia and remote-control drug release.</a> Theranostics. 8, 834-844 (2014).</li><li>Suzuki, D., Kawaguchi, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stimuli-sensitive+core/shell+template+particles+for+immobilizing+inorganic+nanoparticles+in+the+core.">Stimuli-sensitive core/shell template particles for immobilizing inorganic nanoparticles in the core.</a> Colloid Polym Sci. 284, 1443-1451 (2006).</li><li>Bhattacharya, S., Eckert, F., Boyko, V., Pich, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temperature-,+pH-,+and+magnetic-field-sensitive+hybrid+microgels.">Temperature-, pH-, and magnetic-field-sensitive hybrid microgels.</a> Small. 3, 650-657 (2007).</li><li>Wong, J. E., Gaharwar, A. K., Muller-Schulte, D., Bahadur, D., Richtering, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dual-stimuli+responsive+PNiPAM+microgel+achieved+via+layer-by-layer+assembly:+Magnetic+and+thermoresponsive.">Dual-stimuli responsive PNiPAM microgel achieved via layer-by-layer assembly: Magnetic and thermoresponsive.</a> J Colloid Interf Sci. 324, 47-54 (2008).</li><li>Zhao, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Active+scaffolds+for+on-demand+drug+and+cell+delivery.">Active scaffolds for on-demand drug and cell delivery.</a> Proc. Natl. Acad. Sci. U.S.A. 108, 67-72 (2011).</li><li>Xu, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Release+of+magnetic+nanoparticles+from+cell-encapsulating+biodegradable+nanobiomaterials.">Release of magnetic nanoparticles from cell-encapsulating biodegradable nanobiomaterials.</a> ACS nano. 6, 6640-6649 (2012).</li><li>Li, Y. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Magnetic+Hydrogels+and+Their+Potential+Biomedical+Applications.">Magnetic Hydrogels and Their Potential Biomedical Applications.</a> Adv Funct Mater. 23, 660-672 (2013).</li><li>Cooperstein, M. A., Canavan, H. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+cytotoxicity+of+(N-isopropyl+acrylamide)+and+poly(N-isopropyl+acrylamide)-coated+surfaces.">Assessment of cytotoxicity of (N-isopropyl acrylamide) and poly(N-isopropyl acrylamide)-coated surfaces.</a> Biointerphases. 8, 19 (2013).</li><li>Jorgensen, L., Moeller, E. H., van de Weert, M., Nielsen, H. M., Frokjaer, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparing+and+evaluating+delivery+systems+for+proteins.">Preparing and evaluating delivery systems for proteins.</a> Eur J Pharm Sci. 29, 174-182 (2006).</li><li>Holland, T. A., Tabata, Y., Mikos, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+release+of+transforming+growth+factor-beta+1+from+gelatin+microparticles+encapsulated+in+biodegradable,+injectable+oligo(poly(ethylene+glycol)+fumarate)+hydrogels.">In vitro release of transforming growth factor-beta 1 from gelatin microparticles encapsulated in biodegradable, injectable oligo(poly(ethylene glycol) fumarate) hydrogels.</a> J Control Release. 91, 299-313 (2003).</li><li>Liang, H. C., Chang, W. H., Lin, K. J., Sung, H. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genipin-crosslinked+gelatin+microspheres+as+a+drug+carrier+for+intramuscular+administration:+in+vitro+and+in+vivo+studies.">Genipin-crosslinked gelatin microspheres as a drug carrier for intramuscular administration: in vitro and in vivo studies.</a> J Biomed Mater Res. Part A. 65, 271-282 (2003).</li><li>Solorio, L., Zwolinski, C., Lund, A. W., Farrell, M. J., Stegemann, 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=Gelatin+microspheres+crosslinked+with+genipin+for+local+delivery+of+growth+factors.">Gelatin microspheres crosslinked with genipin for local delivery of growth factors.</a> J Tissue Eng Regen Med. 4, 514-523 (2010).</li><li>Regmi, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hyperthermia+controlled+rapid+drug+release+from+thermosensitive+magnetic+microgels.">Hyperthermia controlled rapid drug release from thermosensitive magnetic microgels.</a> J Mater Chem. 20, 6158-6163 (2010).</li><li>Kim, M. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Magnetic+nanoparticle+targeted+hyperthermia+of+cutaneous+Staphylococcus+aureus+infection.">Magnetic nanoparticle targeted hyperthermia of cutaneous Staphylococcus aureus infection.</a> Ann Biomed Eng. 41, 598-609 (2013).</li><li>Ivkov, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+high+amplitude+alternating+magnetic+fields+for+heat+induction+of+nanoparticles+localized+in+cancer.">Application of high amplitude alternating magnetic fields for heat induction of nanoparticles localized in cancer.</a> Clin Cancer Res. 11, 7093s-7103s (2005).</li><li>Huang, S., Fu, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Naturally+derived+materials-based+cell+and+drug+delivery+systems+in+skin+regeneration.">Naturally derived materials-based cell and drug delivery systems in skin regeneration.</a> J Control Release. 142, 149-159 (2010).</li><li>Malafaya, P. B., Silva, G. A., Reis, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Natural-origin+polymers+as+carriers+and+scaffolds+for+biomolecules+and+cell+delivery+in+tissue+engineering+applications.">Natural-origin polymers as carriers and scaffolds for biomolecules and cell delivery in tissue engineering applications.</a> Adv. Drug Deliv. Rev. 59, 207-233 (2007).</li><li>Shah, R., Kim, J., Agresti, J., Weitz, D., Chu, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+of+monodisperse+thermosensitive+microgels+and+gel+capsules+in+microfluidic+devices.">Fabrication of monodisperse thermosensitive microgels and gel capsules in microfluidic devices.</a> Soft Matter. 4, 2303-2309 (2008).</li><li>Hoare, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Magnetically+triggered+nanocomposite+membranes:+a+versatile+platform+for+triggered+drug+release.">Magnetically triggered nanocomposite membranes: a versatile platform for triggered drug release.</a> Nano letters. 11, 1395-1400 (2011).</li></ol>

The authors have nothing to disclose.

这里所描述的技术演示概念的使用纳米粒子微凝胶杂交的磁热触发药物释放证明。这是通过由京尼平交联的微尺度三维明胶网络内的物理截留的MNP和p（NIPAM- 共 -AAm）链来实现的。磁场响应平台足以响应于远程施加的AMF，这又引发了模型药物，BSA的释放，以产生微粒凝胶内的热量。 A至嵌入两者的MNP和p（NIPAM- 共 -AAm）策略似乎是实现从明胶微凝胶所期望的药物释?...

刺激响应药物输送系统，使响应于内源或外源刺激一个紧密控制的药物递送（例如，温度或pH）已经被广泛地研究作为新型药物递送智能软设备。微尺度水凝胶已被广泛地用作药物递送平台，因为它们赋予可控和持续的药物释放曲线，以及可调的化学和机械性能1-3。特别是，胶体微粒凝胶表现出许多优点，作为药物递送的载体，由于其快速响应外界刺激和合适的可注射到局部组织中以微创方式4。聚（N-异丙基丙烯酰胺）（PNIPAM）或其共聚物已经广泛地在合成热-反应微凝胶通过接枝用的可生物降解/生物相容性的聚合物，包括明胶，壳聚糖，藻酸盐酸或透明质酸PNIPAM通过5,6-，其中在其低临界溶解温度（LCST）PNIPAM的相位转变特性可以用作药物释放7的触发。我们最近证明可生物降解的，基于明胶的热-反应微粒凝胶的制造通过将聚（N- isopropylacrylamide- 共 -丙烯酰胺）[P（NIPAM- 共 -AAm）]链作为三维明胶网络8内的次要组分。明胶/ P（NIPAM- 共 -AAm）微粒凝胶显示出可调谐消溶胀温度增加，这正与牛血清白蛋白（BSA）的释放有关。 在过去的几年里，一直在增加努力，开发出磁响应药物交付平台，可以触发按需时尚9,10药物的释放。为磁响应药物递送平台的合成的基本原理利用超顺磁性纳米颗粒的特性（的MNP）时，他们收到的高频交变磁场（AMF），这将触发一个温度敏感的药物释放产生热量。这适用于在该系统能深定位到组织未来的临床应用的承诺，使得非侵入性和远程控制的药物释放，并可以与热疗治疗和磁共振成像系统10-12被组合。这样的平台包括:（1）的MNP / PNIPAM混合凝胶微粒和13-15（2）宏观水凝胶支架固定结合16-18的MNP。基于PNIPAM-微凝胶平台展示了精细调谐体积相变反应，以磁热刺激。然而，它们仍然依赖于在制造和具有高含量的使用PNIPAM聚合物的复杂和精密的 ​​技术可以潜在细胞毒性，以细胞19，这可能限制了其在体内的应用。宏观支架呈现出相对相比于胶体微粒凝胶LY对外界的刺激反应慢，需要一个微创手术移植。 水包油乳化一直以生产亚毫米或微米尺寸的凝胶颗粒20的标准方法。在该乳液的水 - 油界面，微凝胶颗粒形成球状由于在机械剪切力的水滴的表面能量的最小化。此方法允许产生大量的简单制造过程中水性球形凝胶液滴的，并已成功地采用了用于制造用于药物递送应用21-23基于明胶的微粒凝胶。 这里，我们提出了一个简便的方法通过采用水包油乳化法合成用于药物递送应用magnetothermally响应基于明胶的微粒凝胶。这通过物理地结合的氧化铁的MNP和p（NIPAM- 共同实现-AAM）链作为共价由天然衍生的交联剂京尼平与高频交变磁场（AMF）的应用系统交联的组合，球面微尺度明胶网络中的次要组分。

<table border="0" cellpadding="0" cellspacing="0" width="706">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Gelatin</td>
			<td style="width:204px;">Sigma-Aldrich, MO, USA</td>
			<td style="width:119px;">G2500</td>
			<td style="width:167px;">Gelatin type A, porcine skin</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">poly(N-isopropylacrylamide-co-acrylamide)&#160;</td>
			<td style="width:204px;">Sigma-Aldrich, MO, USA</td>
			<td>738727</td>
			<td>MW=20,000, LCST=34-38 oC</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Silicon oil</td>
			<td style="width:204px;">Sigma-Aldrich, MO, USA</td>
			<td>378372</td>
			<td>Viscosity 350 cSt</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Pluoronic L64</td>
			<td style="width:204px;">Sigma-Aldrich, MO, USA</td>
			<td style="width:119px;">435449</td>
			<td>100 ppm poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol)</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:216px;">genipin</td>
			<td style="width:204px;">TimTec LLC, DE, USA</td>
			<td>ST080860</td>
			<td>Mw = 226.23;&#160;</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Magnetic nanoparticles (MNPs)</td>
			<td style="width:204px;">Micromod Inc, Germany</td>
			<td>79-00-102</td>
			<td>nanomag-D-spio, 100 nm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">TR-BSA</td>
			<td style="width:204px;">Life Technologies, NY USA</td>
			<td>A23017</td>
			<td>Albumin from Bovine Serum (BSA), Texas Red conjugate</td>
		</tr>
	</tbody>
</table>

alternating magnetic field-responsive hybrid gelatin microgels for controlled drug release

磁响应纳米/微工程生物材料，使一个紧密控制的，按需给药已被开发为新的类型的生物医学应用智能软设备。虽然许多磁响应药物递送系统已经证明通过概念研究的或在体内临床前应用中，不是在体外证明功效，其在临床环境中的使用仍然可以通过生物 ​​相容性或生物降解性不足的限制。此外，许多现有的平台依靠自己捏造的尖端技术。我们最近通过物理截留聚（N- isopropylacrylamide- 共 -丙烯酰胺）链作为三维明胶网络中的次要组分表现出生物降解性，基于明胶的热-反应微粒凝胶的制造。在这项研究中，我们提出了一个简便的方法来制造可生物降解的药物释放平台，使磁-Thermally触发药物释放。这是通过结合超顺磁性氧化铁纳米颗粒和热 - 反应聚合物基于明胶的胶体微凝胶内，在结合交变磁场的应用系统来实现的。

当正确地进行协议，所制造的微凝胶应表现出在5微米之间微米至20（图1B 和C）的范围内的充分表征的球形形态和胶体分散直径。任一荧光灯的MNP或荧光的BSA可以用来确认是否的MNP或药物（BSA在这项研究中）的微粒凝胶（图1D）内适当包封。所制作的微凝胶可以稳定且存储在没有任何酶降解剂，包括胶原酶摄氏 4度长达4周。的p?...

Watch this Scientific Journal Video about Alternating Magnetic Field-Responsive Hybrid Gelatin Microgels for Controlled Drug Release at JoVE.com

Alternating Magnetic Field-Responsive Hybrid Gelatin Microgels for Controlled Drug Release

交变磁场敏感的混合明胶微凝胶药物控释

我们提出了一个简便的方法来制造可生物降解的明胶释药的平台，磁热响应。这是通过由京尼平交联的球形明胶微网内掺入超顺磁性氧化铁纳米颗粒和聚（N- isopropylacrylamide- 共 -丙烯酰胺），在结合交变磁场的应用系统来实现的。

Magnetically-responsive nano/micro-engineered biomaterials that enable a tightly controlled, on-demand drug delivery have been developed as new types of ...

alternating-magnetic-field-responsive-hybrid-gelatin-microgels-for

Research

JoVE Journal

Bioengineering

9.7K 次观看.  Kent State University. 我们提出了一个简便的方法来制造可生物降解的明胶释药的平台，磁热响应。这是通过由京尼平交联的球形明胶微网内掺入超顺磁性氧化铁纳米颗粒和聚（N- isopropylacrylamide- 共 -丙烯酰胺），在结合交变磁场的应用系统来实现的。 

视频: Alternating Magnetic Field-Responsive Hybrid Gelatin Microgels for Controlled Drug Release

Magnetically-Assisted Remote Controlled Microcatheter Tip Deflection under Magnetic Resonance Imaging

X-ray fluoroscopy-guided endovascular procedures have several significant limitations, including difficult catheter navigation and use of ionizing radiation, which can potentially be overcome using a magnetically steerable catheter under MR guidance.
	The main goal of this work is to develop a microcatheter whose tip can be remotely controlled using the magnetic field of the MR scanner. This protocol aims to describe the procedures for applying current to the microcoil-tipped microcatheter to produce consistent and controllable deflections.
	A microcoil was fabricated using laser lathe lithography onto a polyimide-tipped endovascular catheter. In vitro testing was performed in a waterbath and vessel phantom under the guidance of a 1.5-T MR system using steady-state free precession (SSFP) sequencing. Various amounts of current were applied to the coils of the microcatheter to produce measureable tip deflections and navigate in vascular phantoms.
	The development of this device provides a platform for future testing and opportunity to revolutionize the endovascular interventional MRI environment.

Current applied to an endovascular microcatheter with microcoil tip made by laser lathe lithography can achieve controllable deflections under magnetic resonance (MR) guidance, which may improve speed and efficacy of navigation of vasculature during various endovascular procedures.

磁力辅助的远程控制微导管尖端偏转根据磁共振成像

X-ray fluoroscopy-guided  endovascular procedures have several significant limitations, including  difficult catheter navigation and use of ionizing ...

科研

生物工程

Characteristics of Precipitation-formed Polyethylene Glycol Microgels Are Controlled by Molecular Weight of Reactants

This work describes the formation of poly(ethylene glycol) (PEG) microgels via a photopolymerized precipitation reaction. Precipitation reactions offer several advantages over traditional microsphere fabrication techniques. Contrary to emulsion, suspension, and dispersion techniques, microgels formed by precipitation are of uniform shape and size, i.e.&#160;low polydispersity index, without the use of organic solvents or stabilizers. The mild conditions of the precipitation reaction, customizable properties of the microgels, and low viscosity for injections make them applicable for in vivo purposes. Unlike other fabrication techniques, microgel characteristics can be modified by changing the starting polymer molecular weight. Increasing the starting PEG molecular weight increased microgel diameter and swelling ratio. Further modifications are suggested such as encapsulating molecules during microgel crosslinking. Simple adaptations to the PEG microgel building blocks are explored for future applications of microgels as drug delivery vehicles and tissue engineering scaffolds.

This work describes the formation of poly(ethylene glycol) (PEG) microgels via a photopolymerized precipitation reaction. Increasing the PEG molecular weight increased microgel diameter and swelling ratio. Simple adaptations to the PEG microgel precipitation reaction are explored for future applications of microgels as drug delivery vehicles and tissue engineering scaffolds.

This work describes the formation of poly(ethylene glycol) (PEG) microgels via a photopolymerized precipitation reaction. Precipitation reactions offer ...

Hybrid &#181;CT-FMT imaging and image analysis

Fluorescence-mediated tomography (FMT) enables longitudinal and quantitative determination of the fluorescence distribution in vivo and can be used to assess the biodistribution of novel probes and to assess disease progression using established molecular probes or reporter genes. The combination with an anatomical modality, e.g., micro computed tomography (&#181;CT), is beneficial for image analysis and for fluorescence reconstruction. We describe a protocol for multimodal &#181;CT-FMT imaging including the image processing steps necessary to extract quantitative measurements. After preparing the mice and performing the imaging, the multimodal data sets are registered. Subsequently, an improved fluorescence reconstruction is performed, which takes into account the shape of the mouse. For quantitative analysis, organ segmentations are generated based on the anatomical data using our interactive segmentation tool. Finally, the biodistribution curves are generated using a batch-processing feature. We show the applicability of the method by assessing the biodistribution of a well-known probe that binds to bones and joints.

Hybrid  &#181;CT-FMT imaging and image analysis

We describe a protocol for hybrid imaging, combining fluorescence-mediated tomography (FMT) with micro computed tomography (&#181;CT). After fusion and reconstruction, we perform interactive organ segmentation to extract quantitative measurements of the fluorescence distribution.

混合μCT-FMT成像和图像分析

Fluorescence-mediated tomography (FMT) enables longitudinal and quantitative determination of the fluorescence distribution in vivo and can be used to ...

Custom-designed Laser-based Heating Apparatus for Triggered Release of Cisplatin from Thermosensitive Liposomes with Magnetic Resonance Image Guidance

Liposomes have been employed as drug delivery systems to target solid tumors through exploitation of the enhanced permeability and retention (EPR) effect resulting in significant reductions in systemic toxicity. Nonetheless, insufficient release of encapsulated drug from liposomes has limited their clinical efficacy. Temperature-sensitive liposomes have been engineered to provide site-specific release of drug in order to overcome the problem of limited tumor drug bioavailability. Our lab has designed and developed a heat-activated thermosensitive liposome formulation of cisplatin (CDDP), known as HTLC, to provide triggered release of CDDP at solid tumors. Heat-activated delivery in vivo was achieved in murine models using a custom-built laser-based heating apparatus that provides a conformal heating pattern at the tumor site as confirmed by MR thermometry (MRT). A fiber optic temperature monitoring device was used to measure the temperature in real-time during the entire heating period with online adjustment of heat delivery by alternating the laser power. Drug delivery was optimized under magnetic resonance (MR) image guidance by co-encapsulation of an MR contrast agent (i.e.,&#160;gadoteridol) along with CDDP into the thermosensitive liposomes as a means to validate the heating protocol and to assess tumor accumulation. The heating protocol consisted of a preheating period of 5 min prior to administration of HTLC and 20 min heating post-injection. This heating protocol resulted in effective release of the encapsulated agents with the highest MR signal change observed in the heated tumor in comparison to the unheated tumor and muscle. This study demonstrated the successful application of the laser-based heating apparatus for preclinical thermosensitive liposome development and the importance of MR-guided validation of the heating protocol for optimization of drug delivery.

AN MRI-compatible&#160;custom-designed laser-based heating apparatus has been developed to provide local heating of subcutaneous tumors in order to activate release of agents from thermosensitive liposomes specifically at the tumor region.

定制设计的基于激光的加热装置顺铂触发释放的热敏脂质体与磁共振成像制导

Liposomes have been employed as drug delivery systems to target solid tumors through exploitation of the enhanced permeability and retention (EPR) effect ...

Composite Scaffolds of Interfacial Polyelectrolyte Fibers for Temporally Controlled Release of Biomolecules

Various scaffolds used in tissue engineering require a controlled biochemical environment to mimic the physiological cell niche. Interfacial polyelectrolyte complexation (IPC) fibers can be used for controlled delivery of various biological agents such as small molecule drugs, cells, proteins and growth factors. The simplicity of the methodology in making IPC fibers gives flexibility in its application for controlled biomolecule delivery. Here, we describe a method of incorporating IPC fibers into two different polymeric scaffolds, hydrophilic polysaccharide and hydrophobic polycaprolactone, to create a multi-component composite scaffold. We showed that IPC fibers can be easily embedded into these polymeric structures, enhancing the capability for sustained release and improved preservation of biomolecules. We also created a composite polymeric scaffold with topographical cues and sustained biochemical release that can have synergistic effects on cell behavior. Composite polymeric scaffolds with IPC fibers represent a novel and simple method of recreating the cellular niche.

Scaffolds for tissue engineering need to recapitulate the complex biochemical and biophysical microenvironment of the cellular niche. Here, we show the use of interfacial polyelectrolyte complexation fibers as a platform to create composite, multi-component polymeric scaffolds with sustained biochemical release.

界面聚电解质纤维的生物分子在时间控释复合支架

Various scaffolds used in tissue engineering require a controlled biochemical environment to mimic the physiological cell niche. Interfacial ...

Magnetic and Thermal-sensitive Poly(N-isopropylacrylamide)-based Microgels for Magnetically Triggered Controlled Release

Magnetically and thermally sensitive poly(N-isopropylacrylamide) (PNIPAAm)/Fe3O4-NH2 microgels with the encapsulated anti-cancer drug curcumin (Cur) were designed and fabricated for magnetically triggered release. PNIPAAm-based magnetic microgels with a spherical structure were produced via a temperature-induced emulsion followed with physical-crosslinking by mixing PNIPAAm, polyethylenimine (PEI), and Fe3O4-NH2 magnetic nanoparticles. Because of their dispersity, the Fe3O4-NH2 nanoparticles were embedded inside the polymer matrix. The amine groups exposed on the Fe3O4-NH2 and PEI surface supported the spherical structure by physically crosslinking with the amide groups of the PNIPAAm. The hydrophobic anti-cancer drug curcumin can be dispersed in water after encapsulation into the microgels. The microgels were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and UV-Vis spectral analysis. Furthermore, magnetically triggered release was studied under an external high frequency magnetic field (HFMF). A significant &#34;burst release&#34; of curcumin was observed after applying the HFMF to the microgels due to the magnetic inductive heating (hyperthermia) effect. This manuscript describes the magnetically triggered controlled release of Cur-PNIPAAm/Fe3O4-NH2 encapsulated curcumin, which can be potentially applied for tumor therapy.

Magnetic and Thermal-sensitive PolyN-isopropylacrylamide-based Microgels for Magnetically Triggered Controlled Release

This manuscript describes the preparation of magnetic and thermal-sensitive microgels via a temperature-induced emulsion without chemical reaction. These sensitive microgels were synthesized by mixing poly(N-isopropylacrylamide) (PNIPAAm), polyethylenimine (PEI) and Fe3O4-NH2 nanoparticles for the potential use in magnetically and thermally triggered drug-release.

磁性和热敏性聚（<em&gt;ñ</em基于异丙基丙烯酰胺）的微凝胶用于磁触发控制释放

Magnetically and thermally sensitive poly(N-isopropylacrylamide) (PNIPAAm)/Fe3O4-NH2 microgels with the encapsulated anti-cancer drug curcumin (Cur) were ...

Repressing Gene Transcription by Redirecting Cellular Machinery with Chemical Epigenetic Modifiers

Regulation of chromatin compaction is an important process that governs gene expression in higher eukaryotes. Although chromatin compaction and gene expression regulation are commonly disrupted in many diseases, a locus-specific, endogenous, and reversible method to study and control these mechanisms of action has been lacking. To address this issue, we have developed and characterized novel gene-regulating bifunctional molecules. One component of the bifunctional molecule binds to a DNA-protein anchor so that it will be recruited to an allele-specific locus. The other component engages endogenous cellular chromatin-modifying machinery, recruiting these proteins to a gene of interest. These small molecules, called chemical epigenetic modifiers (CEMs), are capable of controlling gene expression and the chromatin environment in a dose-dependent and reversible manner. Here, we detail a CEM approach and its application to decrease gene expression and histone tail acetylation at a Green Fluorescent Protein (GFP) reporter located at the Oct4 locus in mouse embryonic stem cells (mESCs). We characterize the lead CEM (CEM23) using fluorescent microscopy, flow cytometry, and chromatin immunoprecipitation (ChIP), followed by a quantitative polymerase chain reaction (qPCR). While the power of this system is demonstrated at the Oct4 locus, conceptually, the CEM technology is modular and can be applied in other cell types and at other genomic loci.

Regulation of the chromatin environment is an essential process required for proper gene expression. Here, we describe a method for controlling gene expression through the recruitment of chromatin-modifying machinery in a gene-specific and reversible manner.

用化学表观修饰因子重定向细胞机械抑制基因转录

Regulation of chromatin compaction is an important process that governs gene expression in higher eukaryotes. Although chromatin compaction and gene ...

Use of High-Throughput Automated Microbioreactor System for Production of Model IgG1 in CHO Cells

Automated microscale bioreactors (15 mL) can be a useful tool for cell culture engineers. They facilitate the simultaneous execution of a wide variety of experimental conditions while minimizing potential process variability. Applications of this approach include: clone screening, temperature and pH shifts,&#160;media and supplement optimization. Furthermore, the small reactor volumes are conducive to large Design of Experiments that investigate a wide range of conditions. This allows upstream processes to be significantly optimized before scale-up where experimentation is more limited in scope due to time and economic constraints. Automated microscale bioreactor systems offer various advantages over traditional small scale cell culture units, such as shake flasks or spinner flasks. However, during pilot scale process development&#160;significant care must be taken to ensure that these advantages are realized. When run with care, the system can enable high level automation, can be programmed to run DOE&#39;s with a higher number of variables&#160;and can reduce sampling time when integrated with a nutrient analyzer or cell counter. Integration of the expert-derived heuristics presented here, with current automated microscale bioreactor experiments can minimize common pitfalls that hinder meaningful results. In the extreme, failure to adhere to the principles laid out here can lead to equipment damage that requires expensive repairs. Furthermore, the microbioreactor systems have small culture volumes&#160;making characterization of cell culture conditions difficult. The number and amount of samples taken in-process in batch mode culture is limited as operating volumes cannot fall below 10 mL. This method will discuss the benefits and drawbacks of microscale bioreactor systems.

A detailed protocol for the concurrent operation of 48 parallel cell cultures under varied conditions in a microbioreactor system is presented. Cell culture process, harvest and subsequent antibody titer analysis are described.

高通量自动 Microbioreactor 系统在 CHO 细胞模型 IgG1 生产中的应用

Automated microscale bioreactors (15 mL) can be a useful tool for cell culture engineers. They facilitate the simultaneous execution of a wide variety of ...

Wet-spinning-based Molding Process of Gelatin for Tissue Regeneration

This article presents an inexpensive method to fabricate gelatin, as a natural polymer, into monofilament fibers or other appropriate forms. Through the wet spinning method, gelatin fibers are produced by smooth extrusion in a suitable coagulation medium. To increase the functional surface of these gelatin fibers and their ability to mimic the features of tissues, gelatin can be molded into a tube form by referring to this concept. Examined by in vitro and in vivo tests, the gelatin tubes demonstrate a great potential for application in tissue engineering. Acting as a suitable filling gap material, gelatin tubes can be used to substitute the tissue in the damaged area (e.g., in the nervous or cardiovascular system), as well as to promote regeneration by providing a direct replacement of stem cells and neural circuitry. This protocol provides a detailed procedure for creating a biomaterial based on a natural polymer, and its implementation is expected to greatly benefit the development of correlative natural polymers, which help to realize tissue regeneration strategies.

We developed and describe a protocol based on the wet spinning concept, for the construction of gelatin-based biomaterials used for the application of tissue engineering.

明胶湿纺成型工艺促进组织再生

This article presents an inexpensive method to fabricate gelatin, as a natural polymer, into monofilament fibers or other appropriate forms. Through the ...

Primary Clarification of CHO Harvested Cell Culture Fluid using an Acoustic Separator

Primary clarification is an essential step in a biomanufacturing process for the initial removal of cells from therapeutic products within the harvested cell culture fluid. While traditional methods like centrifugation or filtration are widely implemented for cell removal, the equipment for these processes have large footprints and operation can involve contamination risks and filter fouling. Additionally, traditional methods may not be ideal for continuous bioprocessing schemes for primary clarification. Thus, an alternate application using acoustic (sound) waves was investigated to continuously separate cells from the cell culture fluid. Presented in this study is a detailed protocol for using a bench-scale acoustic wave separator (AWS) for the primary separation of culture fluid containing a monoclonal IgG1 antibody from a CHO cell bioreactor harvest. Representative data are presented from the AWS and demonstrate how to achieve effective cell clarification and product recovery. Finally, potential applications for AWS in continuous bioprocessing are discussed. Overall, this study provides a practical and general protocol for the implementation of AWS in primary clarification for CHO cell cultures and further describes its application potential in continuous bioprocessing.

Presented here is a protocol for the primary clarification of CHO cell culture using an acoustic separator. This protocol can be used for the primary clarification of shake flask cultures or bioreactor harvests and has the potential application for continuous clarification of the cell bleed material during perfusion bioreactor operations.

使用声学分离器对CHO收获的细胞培养液进行初步澄清

Primary clarification is an essential step in a biomanufacturing process for the initial removal of cells from therapeutic products within the harvested ...

交变磁场敏感的混合明胶微凝胶药物控释

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