EAGER: Design and Processing of Anti-microbial Surfaces Using Polymer Extrusion Additive Manufacturing Embedding Silver Nanoparticles with Enhanced Ion Releasing Kinetics

银纳米颗粒由于其对常见细菌和病毒的强抗微生物能力而在医疗保健应用中具有吸引力。然而，制造抗微生物产品所需的纳米颗粒的浓度可能非常昂贵。与此同时，增材制造在快速生产需要抗菌功能的生物医学设备和个人防护设备方面显示出巨大的潜力。通过将银纳米颗粒结合到用于材料挤出增材制造的聚合物长丝中，可以通过控制加工设置和部件几何形状来显著减少抗微生物部件所需的纳米颗粒量，同时仍然保持抗微生物特性。这项早期概念探索性研究赠款（EAGER）奖支持基础研究，这些研究将获得有关如何掺入银纳米颗粒以及零件几何和加工条件可能影响离子释放动力学和制造零件抗菌能力有效性的知识。研究结果可能会提高在医疗保健应用中减少感染性疾病传播的能力，从而有益于社会福祉。该项目还将通过为路易斯安那州最大的为少数群体服务的社区学院德尔加多社区学院的学生举办讲习班，促进代表性不足群体的学生的制造业教育。参加研讨会的学生将接触到本项目的材料，并在先进制造领域获得额外的教育和研究机会。本研究的目的是了解增材制造工艺和设计如何控制需要抗菌性能的制造表面上的银纳米颗粒的浓度。细菌的粘附和生长以及消除细菌的银离子的释放不仅取决于表面形貌，还取决于零件的内部空隙。该方法的新奇在于采用沉积填充图案、层高度和喷嘴尺寸来生产具有（i）限制有利的附着位点并限制表面细菌生长的具有高曲折度的表面形貌的样品，以及（ii）增加的内部空隙，同时不牺牲其他组件性能，以在部件表面处获得抗微生物银离子的更高释放速率。跨学科的研究小组将测试这些结果的表征标本形态，银离子释放率，并通过光学和电子显微镜，质谱和抗菌试验，分别常见的细菌大肠杆菌和金黄色葡萄球菌的粘附和生长。该项目将更好地了解增材制造工艺和设计参数如何影响抗菌机制，它可用于开发各种成本的设计策略，该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查进行评估，被认为值得支持的搜索.

Silver nanoparticles are appealing for healthcare applications because of their strong antimicrobial ability against common bacteria and viruses. However, the concentration of nanoparticles needed to manufacture antimicrobial products can be prohibitively costly. Meanwhile, additive manufacturing has shown great potential for the rapid production of biomedical devices and personal protective equipment that desire an antimicrobial function. By incorporating silver nanoparticles into polymer filaments for material extrusion additive manufacturing, the nanoparticle quantity needed for antimicrobial parts may be substantially reduced through controlling processing settings and part geometry, while still maintaining antimicrobial characteristics. This EArly-concept Grants for Exploratory Research (EAGER) award supports fundament research that will gain knowledge on how silver nanoparticles incorporated as well as part geometric and processing conditions may influence ion releasing kinetics and the effectiveness in antimicrobial ability of fabricated parts. The research outcomes may potentially improve the ability to reduce the spread of infection diseases in medical care applications and thus benefit the well-being of the society. This project will also contribute to the education in manufacturing for students from underrepresented groups through the development of a workshop that targets students from Delgado Community College, the largest minority-serving community college in Louisiana. Students attending the workshop will gain exposures to the materials of this project and additional education and research opportunities in advanced manufacturing areas.The objective of this research is to understand how additive manufacturing processing and designs govern the concentration of silver nanoparticles on fabricated surfaces that require antimicrobial properties. The adhesion and growth of bacteria and the release of silver ions that eradicate bacteria depend not only on surface topography but also the internal voids of a part. The novelty of the approach lies upon employing deposition infill patterns, layer heights, and nozzle sizes to produce specimens with (i) surface topography with high tortuosity that limits favorable attachment sites and confines the growth of surface bacteria, and (ii) increased internal voids, while without sacrificing other component performance, for a higher release rate of antimicrobial silver ions at part surfaces. The interdisciplinary research team will test these outcomes by characterization of specimen morphologies, silver ion release rates, and the adhesion and growth of the common bacteria Escherichia coli and Staphylococcus aureus by optical and electron microscopy, mass spectrometry, and antimicrobial assays, respectively. The project will offer a better understanding of how additive manufacturing processing and design parameters influence the antimicrobial mechanisms, which can be used to develop design strategies for a wide range of cost-effective healthcare applications that can be used to limit infection rates.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.