Overview: Nanomedicine

   Perturbations in the homeostasis of cells by invading organisms, accumulation of pathologic substances, and uncontrolled cell growth provide the underlying basis for most morbid and mortal illness. As such, the challenge of manipulating cellular functions for desired outcomes, such as cancer eradication, controlling viral infection onset as well as stem cell differentiation collectively toward therapeutic gain lies within the complexity of the system of regulatory circuitries that govern cellular pheno-/genotypes. The goal for this Center is to investigate and manipulate the complex cell signaling/regulatory network circuitries in a time-resolved dynamic manner in order to not only enhance our understanding of individual pathways but also provide vital information on their co-dependence and interactivities for the potential of controlling the cell phenotype. Our unique approach employs a systemic view of controlling networks that has the ability to i) perturb the cellular network circuitry, ii) conduct real time monitoring of the key signaling elements, iii) interpret and analyze the system's response, and iv) use a global system control algorithm to dissect and analyze the cellular network circuitry. This approach addresses the NIH's vision on NDC that “ decisions on the biological systems…guided by the principle that the precise control required to manipulate cellular components will depend upon understanding and using engineering principles”. Our objective is not only to extend our understandings of local interactions of cellular components but also globally control cellular functions through a network of circuitries.

    The hallmark of human disease is unbalanced signaling pathways, triggered by external or internal factors. The main challenge is to determine quantitative pathway networking inside live cells bypassing the need for cellular destruction and analysis of averages. We need to know how these signals are generated, how strong they are, what the components are, where they are in the cell in real-time. Additional challenges to consider include the nature of enzymatic signaling reactions (in other words, one active enzyme may target numerous substrates of the same or different types as part of its signaling relay simultaneously or sequentially within the same or distinct compartments within cells), combinatorial effects (simultaneous or sequential pathway activation, opposing pathway activation, pathway silencing as opposed to activation, pathway crosstalk, and many other potentially non-linear network features too numerous to detail), among others. Most important, is the temporal assessment of the cyto-regulatory networks as the ability to accurately resolve the time constants involved with individual phosphorylation and direct protein-protein binding/unbinding reactions provides an important correlation to the existing basic pathway maps.

The overall goals of t his Center for Cell Controls are to address fundamental challenges in the exploration, investigation, and manipulation of these fascinating networks of signal transductions in cells. For example, deletion of the PTEN tumor suppressor gene can lead to neural stem cell expansion but hematopoietic stem cell exhaustion. Similarly, over expression of a polycomb-like gene, Bmi is known to associate with human leukemia and brain tumor development. Thus, to take advantage of stem cell ability for self-renewal and differentiation into multiple lineages for therapeutic purposes, we first need to understand and monitor the pathways involved in these processes. ( http://labs.pharmacology.ucla.edu/hwulab/ )

Viruses are the etiologic agents of many significant diseases and the cause of emerging infections that pose a severe risk to immunologically naïve human populations.  Currently, viral infections are often treated by dampening host symptoms rather than directly counteracting viral replication. This lack of effective antiviral therapy is a critical limitation to the treatment of virally-induced diseases including hepatitis and many respiratory infections. We hope to understand how host cells recognize viral infection and generate cellular responses to inhibit viral replication.   We are also interested in the various mechanisms viruses have evolved to counteract cellular antiviral responses in the host. Our goal is to develop novel strategies to inhibit viral replication without compromising normal host cellular functions. ( http://www.mimg.ucla.edu/faculty/cheng/ )

Cancer is a disease resulting from complex environmental and genetic/epigenetic causes that evolves over time. According to the classic Hanahan and Weinberg scheme, cancer cells demonstrate six new properties that make them increasingly independent of their environment, resulting in maladaptive responses that are radically different from normal cells. Cancer is known to result from chronic activation of key intracellular signaling pathways. These chronically activated pathways may serve as compelling molecular targets for therapy. The collective experience with imatinib, and small molecule EGFR inhibitors makes it clear that successful translation of targeted therapy requires molecular understanding of why certain patients respond while others do not.

Currently, this is achieved retrospectively by detailed profiling of patient tumor tissue for specific molecular lesions, followed by correlating the presence or absence of these lesions to clinical outcome. Today, an increasing number of signaling pathway inhibitors enter the clinic without a clear molecular rationale for how to design clinical trials that maximize the chance of treating the appropriate patient population. Understanding how to rationally apply molecularly targeted therapies in the context of clearly defined genetic and pathway lesions may be a key step in developing rational approaches to molecularly targeted therapies for disease. Technologies developed will allow accurate measurement of the strengths of three major intracellular signaling pathways, known to be critical for health and disease, and monitor their responses to specific targeting agents in real-time. ( http://www.teitell-lab.com/ )

Smart Petri Dish with a Unique Suite of Nanomodalities

Smart Petri Dish with a Unique Suite of Nanomodalities - Members of our Center have developed many unique nano/micro technologies which enable us to sense and manipulate individual molecule or cell for studying the cellular functions and for directing cells toward desired destiny.

Nano/Micro Fluidics – backbone technology for bio-medical researches : Living subjects sustain their lives in fluid. The capability to move nano particles, bio-molecules or cells, of different species in a desired manner plays a major role in studying bio-medical sciences . The fluidic processes include moving, stopping and mixing of fluids as well as separating and concentrating embedded particles. Strong surface molecular effects and high viscous dissipation are the main challenges for handling fluids in micron-size bio-chemical reactors. Our group has extensively studied the rich nano/micro fluidic phenomena for 15 years, since the dawn of the microfluidics field. We examined the interactions of fluid and surface molecules. Various surface property controls have been developed for optimize the bio-chemical processing. Actuation schemes, including electrokinetic, hydrodynamic or magnetic forces, have been developed for controlling fluidic processes in micro/nano bio-reactors. ( http://ho.seas.ucla.edu/ )

Optoelectronic tweezers (OET) - moving nanoparticles, cells and organelles with an optical micromachine : OET enables single-cell trapping at an operational power density that is one hundred thousand times less than that of a traditional laser tweezers setup. OET is based on a new mechanism called light-induced dielectrophoresis, which enables an optical beam to create a virtual electrode on a photoconductor-coated surface, producing a highly non-uniform electric field. The generation of a dielectrophoretic force locally by an optical beam allows for trapping, transporting, or sorting of cells with the potential to move particles or subcellular organelles down to 100 nm in size using optical power as low as 1 m W. ( http://www.eecs.berkeley.edu/%7Ewu/ )

Nanoscope - seeing nanoscale events of live cells: For direct observations of molecular activities of live cells, a fundamental challenge to overcome is that the dimensions of biomolecules and their interactions are far below the diffraction limit of visible light (200 nm). Electron microscopes can probe nanoscale particles but not within living cells. We utilize materials with negative permittivity that amplify near-field optical waves with extremely short wavelengths. A “super-lens” based on this physical property can realize a “nanoscope” which has the potential to visualize the real-time motion of biomolecules, in their native state, at spatial resolutions far below the current limit. We are now able to spatially resolve images at 60 nm, such as microtubules, using a silver super-lens. The continued development of the nanoscope will enable direct visualization of objects at 10 nm resolution.( http://www.me.berkeley.edu/faculty/zhang/ )
Sonocytology – feeling cell system responses: Several recent studies on the native oscillations and force required for membrane deformation by our members have established a new field termed “sonocytology”. An atomic force microscope (AFM) is used to probe the surface of cells under a variety of external and internal environmental conditions to obtain an oscillatory signal of nanomechanical origin. This oscillatory, periodic signal can be converted into sound and used as an indicator of cell health. The nanoscopic motion of the eukaryote yeast cell wall has been mechanistically linked to specific metabolic states, as well as responses to external perturbations and genetic differences. Sonocytology also enables cell damage detection; for example, when microtubule and actin dissociating agents used in chemotherapy are added, a change in cell elasticity is discernable much earlier than biochemical measurements of cell death. ( http://www.teitell-lab.com/ ) and ( http://www.chem.ucla.edu/dept/Faculty/gimzewski/ )
Smart Petri Dish - integrated engineering system of nanomodalities for controlling biological cellular system : Cells and whole organisms detect, process, and respond to changes in their external and internal environments. Current methods for controlling and monitoring these responses in real time are largely lacking and form our main resea rc h motivation. In this center, we propose to use nanotechnology to characterize and manipulate intracellular functional molecules and to use engineering system principles to analyze and control regulatory ci rc uitries of the cell. System control theories and feedback control principles that have been well established in the field of engineering can further offer insights and solutions in dissecting complex cellular network circuitries. Micro-electromechanical-system technology (MEMS) and nanotechnology offer advantages over conventional cellular and molecular analysis methods such as increase in detection speed, reduction in reagent volume, and precise control of objects (cells, proteins, molecules) under investigation and their microenvironment. We will use a generic smart Petri dish platform to conduct many of cellular studies proposed by the Center for Cell Controls. This platform consists of a microfluidic system that has precise fluid and particle handling capabilities. It also has a cell manipulation system using technologies such as OET that can move and barricade cells while precisely controlling their microenvironment and external stimulus. The platform will be equipped with real-time molecular detection sensors. This all-encompassing system platform will also be able to accommodate future modalities generated by our Center member labs and by Nanomedicine Development Centers (NDC). Furthermore, control algorithms will be integrated with the nanomodalities to form a smart Petri dish which can provide real-time sensing, decision and stimulation to control and understand the cellular functions.