We present a two-photon microscope that is approximately 2.9 g in mass and 2.0 x 1.9 x 1.1 cm(3) in size and based on a microelectromechanical systems (MEMS) laser-scanning mirror. The microscope has a focusing motor and a micro-optical assembly composed of four gradient refractive index lenses and a dichroic microprism. Fluorescence is captured without the detected emissions reflecting off the MEMS mirror, by use of separate optical fibers for fluorescence collection and delivery of ultrashort excitation pulses. Using this microscope we imaged neocortical microvasculature and tracked the flow of erythrocytes in live mice.
"Combined, the promise is that, by searching the enormous chemical space of small molecules and of proteins, we would greatly extend the current repertoire of ROS indicators and ultimately achieve the same level of reliability as we have enjoyed while measuring intracellular Ca2+ with small-molecule probes such as fluo-3 , fura-2 , indo-1 , and fluorescent protein probes such as GCamp6  and GECOs, the palette with blue, improved green, and or red-shifted indicators . In synergy with the exponentially increasing numbers of indicator-expressing organisms and disease models, the booming technology for super-resolution and single-molecule imaging [113–115], and the trend for using miniature, plant-in devices to obtain images in conscious, free-moving animals [116–120], imaging ROS in vivo will serve as the most powerful force to transform the landscape and push forward the frontiers in ROS signaling. "
[Show abstract][Hide abstract] ABSTRACT: Reactive oxygen species (ROS) act as essential cellular messengers, redox regulators, and, when in excess, oxidative stressors that are widely implicated in pathologies of cancer and cardiovascular and neurodegenerative diseases. Understanding such complexity of the ROS signaling is critically hinged on the ability to visualize and quantify local, compartmental, and global ROS dynamics at high selectivity, sensitivity, and spatiotemporal resolution. The past decade has witnessed significant progress in ROS imaging at levels of intact cells, whole organs or tissues, and even live organisms. In particular, major advances include the development of novel synthetic or genetically encoded fluorescent protein-based ROS indicators, the use of protein indicator-expressing animal models, and the advent of in vivo imaging technology. Innovative ROS imaging has led to important discoveries in ROS signaling-for example, mitochondrial superoxide flashes as elemental ROS signaling events and hydrogen peroxide transients for wound healing. This review aims at providing an update of the current status in ROS imaging, while identifying areas of insufficient knowledge and highlighting emerging research directions.
Journal of Molecular Medicine 07/2013; 91(8). DOI:10.1007/s00109-013-1067-4 · 5.11 Impact Factor
"In this paper, we present data acquired with the dual-axes confocal microscopes as well as a miniature two-photon fluorescence microscope – , as shown in Fig. 2(c), and a commercially available confocal microendoscope , as shown in Fig. 1 "
[Show abstract][Hide abstract] ABSTRACT: Recent advances in optical imaging have led to the development of miniature microscopes that can be brought to the patient for visualizing tissue structures in vivo. These devices have the potential to revolutionize health care by replacing tissue biopsy with in vivo pathology. One of the primary limitations of these microscopes, however, is that the constrained field of view can make image interpretation and navigation difficult. In this paper, we show that image mosaicing can be a powerful tool for widening the field of view and creating image maps of microanatomical structures. First, we present an efficient algorithm for pairwise image mosaicing that can be implemented in real time. Then, we address two of the main challenges associated with image mosaicing in medical applications: cumulative image registration errors and scene deformation. To deal with cumulative errors, we present a global alignment algorithm that draws upon techniques commonly used in probabilistic robotics. To accommodate scene deformation, we present a local alignment algorithm that incorporates deformable surface models into the mosaicing framework. These algorithms are demonstrated on image sequences acquired in vivo with various imaging devices including a hand-held dual-axes confocal microscope, a miniature two-photon microscope, and a commercially available confocal microendoscope.
"Recent successes in development of two-photon endoscopes were achieved by incorporating microelectromechanical systems (MEMS) scanning mirrors into the microscope design.43,44 Specifically, Piyawattanametha et al have fabricated a lightweight (2.9 g), MEMS-based two-photon microscope and demonstrated its ability to track individual red blood cells flowing in neocortical microvasculature of adult mice, establishing the future potential for two-photon imaging in vivo.45 With further development, multiphoton microscopy combined with dual imaging and therapy GGS-NPs could provide an effective method to pinpoint and treat specific sites following initial tumor detection with wide-field imaging modalities. "
[Show abstract][Hide abstract] ABSTRACT: The goal of this study was to develop near-infrared (NIR) resonant gold-gold sulfide nanoparticles (GGS-NPs) as dual contrast and therapeutic agents for cancer management via multiphoton microscopy followed by higher intensity photoablation. We demonstrate that GGS-NPs exposed to a pulsed, NIR laser exhibit two-photon induced photoluminescence that can be utilized to visualize cancerous cells in vitro. When conjugated with anti-HER2 antibodies, these nanoparticles specifically bind SK-BR-3 breast carcinoma cells that over-express the HER2 receptor, enabling the cells to be imaged via multiphoton microscopy with an incident laser power of 1 mW. Higher excitation power (50 mW) could be employed to induce thermal damage to the cancerous cells, producing extensive membrane blebbing within seconds leading to cell death. GGS-NPs are ideal multifunctional agents for cancer management because they offer the ability to pinpoint precise treatment sites and perform subsequent thermal ablation in a single setting.
International Journal of Nanomedicine 08/2010; 5(1):445-54. · 4.38 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.