Understanding Plasma Assisted Biofilm Inactivation

描述(申请人提供)：生物膜每年给这个国家造成数十亿美元的设备损坏、产品污染、感染以及设备和假体植入物的定居。由于生物膜与浮游生物相比表现出非典型特征，因此生物膜大大削弱了传统微生物根除方法的有效性。因此，要有能力摧毁这些有机体，就需要开发替代技术。该项目广泛而长期的目标是填补缺乏有效的生物膜灭活/灭菌方法的空白。等离子体是物质的第四种状态，它的使用提供了一种新的选择，因为等离子体含有一种被称为杀菌剂的反应剂混合物。尽管有证据表明，血浆有助于灭活细菌生物膜，但在我们了解导致灭活/灭菌的机制并将其应用于医疗或环境目的之前，仍有许多问题尚未解决。本研究的主要目的是了解气体放电等离子体辅助生物膜灭活的机理。其具体目的是：1)确定血浆对生物膜形成细胞生理状态的影响。我们将检验这样一个假设，即血浆影响生物膜形成细胞的生理状态(活力、可培养能力、代谢状态)，其影响取决于生物膜暴露在血浆中的时间和生物膜的年龄。2)确定血浆对结构生物膜形成细胞的影响。我们将检验这一假设，即等离子体影响生物膜形成细胞的结构(细胞膜的完整性和最终存在的孔)，其影响取决于生物膜暴露在等离子体中的时间和生物膜的年龄；以及3)气体等离子体成分与生物膜灭活/灭菌的关系。我们将确定细胞对血浆的反应是一种普遍现象，还是取决于所使用的血浆类型。我们将选择具有特定多样性或丰富反应剂的等离子体环境，并利用它来评估其对生物膜形成细胞结构和生理状态的影响。这项研究将提供一个全面的了解等离子体辅助生物膜灭活及其机制，实现国家卫生研究院的目标#3(到。扩大医学和相关科学的知识基础，以增进国家的经济福祉，并确保公共研究投资的持续高回报)。通过实现这一主要目标，我们希望为未来技术的发展奠定基础，作为长期目标，解决严重的医学问题，履行NIH的使命(追求关于生命系统的性质和行为的基本知识，并应用这些知识来延长健康寿命和减少疾病和残疾的负担)；特别是目标1(促进基本的创造性发现、创新的研究战略及其应用，作为显著提高国家保护和改善健康的能力的基础)。 与公共卫生相关：生物膜污染普通家庭表面和许多医疗设备(如导管、隐形眼镜、机械心脏瓣膜、关节置换等)，导致疾病和死亡。破坏生物膜所需的大剂量抗菌剂在环境上是不可取的，可能对患者有害。因此，要有能力摧毁这些有机体，就需要开发替代技术。等离子体是物质的第四种状态，它提供了一种诱人的选择。本研究将研究等离子体辅助生物膜灭活的机理，长期目标是开发一种易于使用、无害的灭菌方法来破坏生物膜。

DESCRIPTION (provided by applicant): Biofilms cost this nation billions of dollars yearly in equipment damage, product contamination, infections, and colonization of devices and prosthetic implants. The effectiveness of conventional methods of microbial eradication is drastically impaired with biofilms since they exhibit atypical characteristics when compared to their planktonic counterparts. Therefore the ability to destroy these organisms demands the development of alternative techniques. The broad, long term goal of this project is to fill a gap regarding the lack of effective biofilm inactivation/sterilization methods. The use of plasmas, the fourth state of the matter, offers a novel alternative since plasmas contain a mixture of reactive agents individually known as bacteria- killing agents. Although evidence suggests that plasma is useful to inactivate bacterial biofilms, there are still many unresolved questions before we can understand the mechanism that causes inactivation/sterilization and apply it for medical or environmental purposes. The main goal of this research is to understand the mechanisms leading to gas discharge plasma-assisted biofilm inactivation. The specific aims are: 1) to determine the effect of plasma on the physiological status of biofilms-forming cells. We will test the hypothesis that plasma affects the physiological status (viability, culturability, metabolic status) of biofilm- forming cells and the effect depends on the amount of time that biofilms have been exposed to plasma and the age of the biofilm. 2) to determine the effect of plasma on the structure biofilm-forming cells. We will test he hypothesis that plasma affects the structure (integrity of cell envelopes and eventual presence of pores) of biofilm-forming cells, and the effect depends on the amount of time that biofilms have been exposed to plasma and the age of the biofilm; and 3) to relate gas-plasma composition with biofilm inactivation/sterilization. We will determine whether the response of cells to plasma is a general phenomenon or if it depends on the type of plasma used. We will select a plasma environment with a particular diversity or abundance of reactive agents and we will use it to evaluate its effect on biofilm-forming cells structure and physiological status. This study will provide a comprehensive understanding of plasma-assisted-biofilm inactivation and its mechanisms, fulfilling NIH's goal #3 (to. expand the knowledge base in medical and associated sciences in order to enhance the Nation's economic well-being and ensure a continued high return on the public investment in research). By achieving this main goal we expect to build the basis for the future development of a technology that will, as a long-term goal, solve a serious medical problem, fulfilling NIH's mission (Science in pursuit of fundamental knowledge about the nature and behavior of living systems and the application of that knowledge to extend healthy life and reduce the burdens of illness and disability); and particularly goal # 1 (to foster fundamental creative discoveries , innovative research strategies, and their applications as a basis to advance significantly the Nation's capacity to protect and improve health). PUBLIC HEALTH RELEVANCE: Biofilms contaminate common household surfaces and many medical devices, (e.g., catheters, contact lenses, mechanical heart valves, joint replacements, etc.), causing illness and death. The huge doses of antimicrobials required to destroy biofilms are environmentally undesirable and may be hazardous to a patient. Therefore, the ability to destroy these organisms demands the development of alternative techniques. Plasmas, the fourth state of matter, offer an attractive alternative. This research will study the mechanisms of plasma-assisted- biofilm inactivation with the long term goal of developing an easy-to-use, non-hazardous sterilization method to destroy biofilms.