ERI: Magnetic nanoparticles to fight biofilms

细菌通常在表面上以密集、粘性的菌落形式生长，称为生物膜。生物膜可以生长在不同的表面，如医疗植入物、食品容器或船体。不幸的是，生物膜会引起问题，而且它们的去除可能会很困难。例如，在水下的结构或船只部件的情况下，潜水员需要擦洗水下表面。这项研究建议使用磁场和磁性纳米颗粒来远距离去除生物膜。磁性纳米粒子在磁场的交替作用下，会随着磁场的旋转和移动，产生机械力和温升。这两种效应将通过使用不同的磁性纳米颗粒和外加磁场组合来去除模型海洋生物膜来探索，并将在自然海洋生物膜中进行测试。该项目有可能为其他行业产生创新的生物膜去除技术，包括食品工业和医疗保健，影响社会福祉和美国经济。此外，这项研究将涉及本科生和少数民族学生，培养他们的科学兴趣，并为未来的科学职业打开大门。研究人员还将制作易于理解的演示试剂盒，以磁性纳米颗粒与磁场相互作用为特色进行公开分发。细菌生物膜对经济、社会和人类健康有广泛的负面影响，如食品变质、军车损坏和与医疗植入物相关的感染。海洋细菌生物膜生长在各种水下表面，如船体和桥梁基础，可能会损害它们的性能。虽然经常需要物理方法来去除生物膜，但这些方法并不总是可行或实用的，特别是在需要昂贵和危险的潜水作业才能进入水下结构的情况下。该项目将研究在交变磁场下使用磁性纳米颗粒去除海洋生物膜。实验室培养的滨海梭子藻生物膜将被用作模型。不同的磁性纳米颗粒大小、形状和表面涂层将在不同的交变磁场条件下进行测试。生物膜的完整性将通过使用动态磁化率方法对生物膜治疗前后的微观流变学进行量化，并通过荧光成像分析细菌和胞外聚合物的空间分布来评价。一旦建立了磁性纳米颗粒应用和处理的最佳方案，这种方法将在天然海洋生物膜中进行测试。该项目将包括STEM领域代表性不足的本科生，增加他们对科学研究的参与。此外，还将制作演示工具包，展示磁性纳米颗粒在生物医学中的潜在应用。该工具包将用于公开公共活动，以提高普通民众的科学素养，并提高对科学进步的认识。该套件还将用于不同人群的招聘活动，鼓励多样性和包容性，为追求STEM职业生涯带来兴奋。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Bacteria often grow in dense, sticky colonies on surfaces, called biofilms. Biofilms can grow on diverse surfaces, such as medical implants, food containers or boat hulls. Unfortunately, biofilms can cause issues, and their removal can be difficult. For example, in the case of structures or parts of boats that are underwater, divers need to scrub the underwater surfaces. This research proposes using magnetic fields and magnetic nanoparticles to remove biofilms from a distance. Magnetic nanoparticles under the action of magnetic fields that alternate direction will rotate and move to follow the magnetic field, generating mechanical forces and temperature increases. These two effects will be explored by using different magnetic nanoparticles and applied magnetic field combinations to remove biofilms of a model marine biofilm, and the approach will be tested in natural marine biofilms. This project has the potential to yield innovative biofilm-removal technologies for other sectors, including the food industry and healthcare, impacting societal wellbeing and the US economy. Additionally, the research will involve undergraduate minority students, fostering their scientific interests and opening doors for future scientific careers. Researchers will also create easy-to-understand demonstration kits for public distribution featuring magnetic nanoparticles interacting with magnetic fields.Bacterial biofilms have a wide range of negative impacts on the economy, society, and human health, such as food spoilage, damage to military vehicles, and infections associated with medical implants. Marine bacterial biofilms grow on various underwater surfaces, like boat hulls and bridge foundations, and can be detrimental for their performance. While physical methods are often needed to remove biofilms, these are not always possible or practical, especially in cases where expensive and risky diving operations are required to access underwater structures. This project will investigate the use of magnetic nanoparticles under alternating magnetic fields to remove marine biofilms. Laboratory grown C. marina biofilms will be used as a model. Different magnetic nanoparticle sizes, shapes and surface coatings will be tested against distinct alternating magnetic field regimes. The biofilm integrity will be evaluated by quantifying the microrheology of the biofilm before and after treatment using dynamic magnetic susceptibility methods, and by analyzing the spatial distribution of bacteria and extracellular polymeric substances using fluorescence imaging. Once an optimal regime for magnetic nanoparticle application and treatment has been established, this approach will be tested with natural marine biofilms. The project will include undergraduate students underrepresented in STEM fields, increasing their involvement in scientific research. Additionally, a demo kit will be created to showcase the potential applications of magnetic nanoparticles in biomedicine. The kit will be used in open public events to increase science literacy among the general population and to raise awareness of scientific progress. This kit will also be used in recruitment events among diverse populations, encouraging diversity and inclusion, generating excitement towards the pursuit of STEM careers.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.