Hüsler Amanda, Haas Simon, Parry Luke, Romero Manuel, Nisisako Takasi, Williams Paul, Wildman Ricky D, Alexander Morgan R
Advanced Materials and Healthcare Technologies Division, School of Pharmacy, University of Nottingham Nottingham NG7 2RD UK
Centre for Additive Manufacturing, Faculty of Engineering, University of Nottingham Nottingham NG7 2RD UK.
RSC Adv. 2018 Apr 24;8(28):15352-15357. doi: 10.1039/c8ra01491d. eCollection 2018 Apr 23.
Micro- and nanoparticles are of great interest because of their potential for trafficking into the body for applications such as low-fouling coatings on medical devices, drug delivery in pharmaceutics and cell carriers in regenerative medicine strategies. Particle production often relies on the use of surfactants to promote stable droplet formation. However, the presence of residual surfactant has been shown to complicate the surface chemistry and resultant properties. When forming particles from polymerizable monomer droplets, these polymeric surfactant chains can become physically entangled in the particle surface. Due to the key role of the outermost layers of the surface in biomaterial interactions, the surface chemistry and its influence on cells needs to be characterized. This is the first study to assess surfactant retention on microfluidic produced particles and its effect on bacterial attachment; surfactant contaminated microparticles are compared with flat films which are surfactant-free. Polymeric microparticles with an average diameter of 76 ± 1.7 μm were produced by using a T-junction microfluidic system to form monomer droplets which were subsequently photopolymerized. Acrylate based monomer solutions were found to require 2 wt% PVA to stabilize droplet formation. ToF-SIMS was employed to assess the surface chemistry revealing the presence of PVA in a discontinuous layer on the surface of microparticles which was reduced but not removed by solvent washing. The effect of PVA on bacterial () attachment was quantified and showed reduction as a function of the amount of PVA retained at the surface. The insights gained in this study help define the structure-function relationships of the particulate biomaterial architecture, supporting materials design with biofilm control.
微米和纳米颗粒因其具有进入人体的潜力而备受关注，可用于诸如医疗器械上的低污染涂层、制药中的药物递送以及再生医学策略中的细胞载体等应用。颗粒生产通常依赖于使用表面活性剂来促进稳定的液滴形成。然而，残留表面活性剂的存在已被证明会使表面化学和最终性能变得复杂。当由可聚合单体液滴形成颗粒时，这些聚合物表面活性剂链可能会在颗粒表面发生物理缠结。由于表面最外层在生物材料相互作用中起着关键作用，因此需要对表面化学及其对细胞的影响进行表征。这是第一项评估微流体制备颗粒上表面活性剂保留情况及其对细菌附着影响的研究；将受表面活性剂污染的微粒与不含表面活性剂的平面薄膜进行比较。通过使用T型结微流控系统形成单体液滴，随后进行光聚合，制备了平均直径为76±1.7μm的聚合物微粒。发现基于丙烯酸酯的单体溶液需要2wt%的聚乙烯醇（PVA）来稳定液滴形成。采用飞行时间二次离子质谱（ToF-SIMS）来评估表面化学，揭示在微粒表面存在一层不连续的PVA层，通过溶剂洗涤该层有所减少但未被去除。定量分析了PVA对细菌附着的影响，结果表明其随着表面保留的PVA量的变化而降低。本研究获得的见解有助于定义颗粒生物材料结构的结构-功能关系，为具有生物膜控制功能的材料设计提供支持。
