This PDF file contains the front matter associated with SPIE Proceedings Volume 7910, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.

Advances in imaging and spectroscopic technologies have enabled the optimization of many therapeutic modalities in cancer and noncancer pathologies either by earlier disease detection or by allowing therapy monitoring. Amongst the therapeutic options benefiting from developments in imaging technologies, photodynamic therapy (PDT) is exceptional. PDT is a photochemistry-based therapeutic approach where a light-sensitive molecule (photosensitizer) is activated with light of appropriate energy (wavelength) to produce reactive molecular species such as free radicals and singlet oxygen. These molecular entities then react with biological targets such as DNA, membranes and other cellular components to impair their function and lead to eventual cell and tissue death. Development of PDT-based imaging also provides a platform for rapid screening of new therapeutics in novel in vitro models prior to expensive and labor-intensive animal studies. In this study we demonstrate how an imaging platform can be used for strategizing a novel combination treatment strategy for multifocal ovarian cancer. Using an in vitro 3D model for micrometastatic ovarian cancer in conjunction with quantitative imaging we examine dose and scheduling strategies for PDT in combination with carboplatin, a chemotherapeutic agent presently in clinical use for management of this deadly form of cancer.

The diagnostic, interrogational, and therapeutic potential of molecular probes is rapidly being investigated and exploited across virtually every biomedical imaging modality. While many types of probes enhance contrast or delivery therapy by static localization to targeted sites, significant potential exists for utilizing dynamic molecular probes. Recent examples include molecular beacons, photoactivatable probes, or controlled switchable drug-releasing particles, to name a few. In this review, we describe a novel class of dynamic molecular probes that rely on the application and control of localized external magnetic fields. These magnetomotive molecular probes can provide optical image contrast through a modulated scattering signal, can interrogate the biomechanical properties of their viscoelastic microenvironment by tracking their underdamped oscillatory step-response to applied fields, and can potentially delivery therapy through nanometer-to-micrometer mechanical displacement or local hyperthermia. This class of magnetomotive agents includes not only magnetic iron-oxide nanoparticles, but also new magnetomotive microspheres or nanostructures with embedded iron-oxide agents. In vitro three-dimensional cell assays and in vivo targeting studies in animal tumor models have demonstrated the potential for multimodal detection and imaging, using magnetic resonance imaging for whole-body localization, and magnetomotive optical coherence tomography for high-resolution localization and imaging.

In photodynamic therapy (PDT), localized monochromatic light is used to activate targeted photosensitizers (PS) to induce cellular damage through the generation of cytotoxic species such as singlet oxygen. While first-generation PS passively targeted malignancies, a variety of targeting mechanisms have since been studied, including specifically activatable agents. Antibody internalization has previously been employed as a fluorescence activation system and could potentially enable similar activation of PS. TAMRA, Rhodamine-B and Rhodamine-6G were conjugated to trastuzumab (brand name Herceptin), a humanized monoclonal antibody with specificity for the human epidermal growth factor receptor 2 (HER2), to create quenched PS (Tra-TAM, Tra-RhoB, and Tra-Rho6G). Specific PDT with Tra-TAM and Tra-Rho6G, which formed covalently bound H-dimers, was demonstrated in HER2+ cells: Minimal cell death (<6%) was observed in all treatments of the HER2- cell line (BALB/3T3) and in treatments the HER2+ cell line (3T3/HER2) with light or trastuzumab only. There was significant light-induced cell death in HER2 expressing cells using Tra-TAM (3% dead without light, 20% at 50 J/cm², 46% at 100 J/cm²) and Tra-Rho6G (5% dead without light, 22% at 50 J/cm², 46% at 100 J/cm²). No efficacy was observed in treatment with Tra-RhoB, which was also non-specifically taken up by BALB/3T3 cells and which had weaker PS-antibody interactions (as demonstrated by visualization of protein and fluorescence on SDS-PAGE).

The development of multifunctional nanomaterials is currently a topic of interest in the field of nanotechnology. Integrated systems that incorporate therapeutics, molecular targeting, and diagnostic imaging capabilities are considered to be the next generation of multifunctional nanomedicine. In this work, we present the first example of using Au nanorods simultaneously serving not only as photodynamic and photothermal agents to destroy A549 malignant cells but also as optical contrast agents simultaneously to monitor cellular image. Au nanorods were successfully conjugated with hydrophilic photosensitizer, indocyanine green (ICG), to achieve photodynamic therapy (PDT) and hyperthermia. With the combination of PDT and hyperthermia proved to be efficiently killing cancer cells as compared to PDT or hyperthermia treatment alone and enhanced the effectiveness of photodestruction. Moreover, Au nanorods conjugated with ICG displayed high chemical stability and simultaneously acted as a promising cellular image probe. As a result, the preparation of Au nanorods conjugated with photosensitizers as well as their use in biomedical applications is valuable developments in multifunctional nanomaterials.

The anti-EGFR antibody, cetuximab, was labeled with IRDye 800CW fluorescent dye and conjugated to gold nanorods (GNR). GNR with aspect ratio of ~ 4 and plasmon resonance peak at ~785 nm were fabricated for use in these experiments. The IRDye:cetuximab:nanorod conjugate treatment with NIR light selectively heated the GNR and was sufficient to treat cancers. Excitation induced fluorescence of the IRDye 800CW enabling real-time imaging. We characterized and optimized the parameters for the conjugation of the GNR to cetuximab to facilitate active targeting of the nanorods to the site of the tumor. This combination of selective targeting, imaging, and photothermal treating of malignant cells is a viable approach for a variety of squamous cell carcinomas.

Modern computational approaches based on quantum mechanical methods to characterize structures and optical spectra of biological chromophores in proteins are intensively used to gain knowledge of events occurring upon of their photoexcitation. Primary attention is paid to the species from the family of the green fluorescent protein applied as biomarkers in living cells. We apply quantum chemical approaches for accurate calculations of the structures of the chromophore binding pockets and to estimate spectral bands corresponding to the S₀-S₁ optical transitions of the intriguing kindling protein asFP595. Its precursor, the chromoprotein asCP from the sea anemony Anemonia sulcata is characterized by distinctive spectral properties: at low light intensities the wild-type protein is weakly fluorescent with the very low quantum yield, however, high intensity irradiation with green light leads to a drastic increase of quantum yield. This phenomenon is now termed "kindling". In simulations, the model system is designed as a molecular cluster constructed on the basis of available crystal structures of the related protein. The equilibrium geometry of the cluster is optimized using density functional theory approximations. The vertical excitation energies corresponding to the S₀-S₁ transitions are computed by using the semiempirical ZINDO technique. A special attention is paid to evaluate effects of point mutations in the vicinity of the chromophore group. Theoretical data provide important information on the chromophore properties aiming to interpret the results of experimental studies and applications of this fluorescent protein.

We have developed a novel real-time intraoperative fluorescence imaging device that can detect near-infrared (NIR) fluorescence and map sentinel lymph nodes (SLNs). In contrast to conventional imaging systems, this device is compact, portable, and battery-operated. It is also wearable and thus allows hands-free operation of clinicians. The system directly displays the fluorescence in its goggle eyepiece, eliminating the need for a remote monitor. Using this device in murine lymphatic mapping, the SLNs stained with indocyanine green (ICG) can be readily detected. Fluorescence-guided SLN resection under the new device was performed with ease. Ex vivo examination of resected tissues also revealed high fluorescence level in the SLNs. Histology further confirmed the lymphatic nature of the resected SLNs.

There are so many Ca²⁺ indicators such as Oregon green 488 BAPTA-1 and cameleon, all of which have moderate Ca²⁺ affinities (K_d > 150 nM). These indicators successfully report changing in Ca²⁺ concentration in most of cells. However, it is known that some cells are estimated to have a very low resting [Ca²⁺] and display very small ▵[Ca²⁺]s, which is below the detection limit of the indicators. To develop high-affinity indicators, we modified a FRET-based Ca²⁺ indicator, yellow cameleon (YC) 2.60 (K_d = 100 nM) because of the brightness and the large dynamic range. By engineering the Ca²⁺ sensing domain, we obtained a series of ultra-sensitive Ca²⁺ indicators. Their high Ca²⁺ affinities (Kd = 15, 30, and 50 nM) enabled detection of subtle Ca²⁺ transients associated with spontaneous network activity in zebrafish. Our measurements revealed that both the resting Ca²⁺ level and the amplitude of Ca²⁺ transients significantly differed by cell type and stimulation, indicating that the selection of indicators with the appropriate K_d is essential for successful in vivo Ca²⁺ imaging. A lineup of such indicators with finely tuned Kd values optimized to detect [Ca²⁺] from 10 nM to 100 nM would enable precise and reliable Ca²⁺ imaging.

Signal transducer and activator of transcription (STAT) 5b is an important protein in JAK-STAT signal pathway and is responsible for the metastasis and proliferation of tumor cells. The determination of the STAT5b expression provides a way to study the mechanism of tumor progress. In this study, gold nanoparticles with different diameters were conjugated to the fluorescein modified STAT5b specific DNA sequence to form the beacon. The procedures for the beacon with better fluorescence properties were optimized. The fluorescence quenching and the recovery properties after hybridizing with mRNA of STAT5b were intensively investigated. Results indicate the gold nanoparticle based beacon is an effective probe for the determination of STAT5b protein expression in JAK-STAT signal pathway and has great potential in the study of drug screening and discovery.

Up-converting nanophosphors consisting of Er activator with Yb sensitizer in a NaYF₄ matrix have been studied for heating and temperature sensing. We show the response of the nanothermometer to a pump laser operating at 1064 nm with a pulse width of 5-7 nS with a 20 Hz repetition rate. The heating pulse (pump) is probed by the change in the ratio of the two characteristic green emissions centered around 525 and 545 nm. A quasi continuous probe laser operating at 80 MHz and 980 nm is employed to study the effect of the pump laser on the phosphor. The emission is characterized by a spectrophotometer attached to a gated intensifier and a charge coupled device. The time gated measurement shows that the heating produced by 1064 nm pulse is easily resolved with time gating, and the read-out of temperature is deciphered based on the temperature calibration performed with the emission lines. It was found that an increasing the energy of the heating pulse caused a drop in the total green intensity, which had a direct correlation to the increase in the temperature. The signal transduction of the thermal characteristics of the phosphor was delayed in time from the arrival of the heating pulse by about two-three decades in the unit of microseconds. The gold coated phosphor also showed a response to the heating pulse, but the enhancement of both the 525 and 545 nm emissions from the gold shell, to varying extents made the deconvolution of temperature quite involved.

Gold nanoparticles are quite popular as contrast agents for optical microscopy. Their strong linear and nonlinear interaction with light, coupled with their biocompatibility and resistance to photobleaching make them suitable contrasts agents for bioimaging applications. Gold nanorods have been used for in vivo two photon microscopy in small animals [PNAS 102, 15752 (2005)]. Conventional two photon microscopy with gold nanorods involves exciting these particles with femtosecond laser at wavelengths close to their longitudinal plasmon resonance (LPR). Most of the reported works used Ti:Sapphire laser with excitation wavelengths ranging from 780 nm to 850 nm. The rational was to maximize absorption of excitation wavelengths, a fraction of which gives rise to two photon luminescence. This however causes intense heating of the nanorods and unless the excitation powers are kept low, gold nanorods tend to melt [Phys Rev Lett 95, 267405 (2005)]. Another less explored way of getting multiphoton emission from gold nanorods is to excite them at long wavelengths far away from their LPR wavelength [Jour Amer Chem Soc 131, 14186 (2009)]. We are interested in femtosecond lasers operating around 1200 nm wavelengths because of their lower scattering and absorption by tissue and water. Here we compare multiphoton photon luminescence properties of gold nanorods when excited at wavelengths around 800 nm and 1200 nm. Excitation with wavelengths around 1200 nm has certain advantages like lower heating of the particles and hence prolonged durations of imaging. Other advantage is the ability to collect emission in the near infrared regions (NIR) up to 800 nm which is not possible when using excitation wavelengths around 800 nm. These features are good for deep tissue imaging. One disadvantage of this approach is lower luminescence intensity.

In nanomedicine, biodistribution studies are critical to evaluate the safety and efficacy of nanoparticles. Currently, extensive biodistribution studies are hampered by the limitations of bulk tissue and single-cell imaging techniques. To ameliorate these limitations, we have developed a novel method for single nanoparticle detection that incorporates a conjugated oligonucleotide as a "nanobarcode" for detection via in situ PCR. This strategy magnifies the detection signal from single nanoparticles, facilitating rapid evaluation of nanoparticle uptake by cell type over larger areas. The nanobarcoding method can enable precise analysis of nanoparticle biodistributions and expedite translation of these nanoparticles to the clinic.

CdHgTe/SiO₂ nanoparticles were prepared by SiO₂ capping on the surface of CdHgTe quantum dots (QDs). The characteristics, such as optical spectra, size and optical stability were investigated. The size of CdHgTe/SiO₂ nanoparticles could be larger than 100 nm after CdHgTe QDs capped with SiO₂. CdHgTe/SiO₂ nanoparticles acted as a novel fluorescence probe have a maximum fluorescence emission of 790 nm and a full width at half-maximum (FWHM) of 50-70 nm. The in vivo fluorescence imaging of CdHgTe/SiO₂ nanoparticles in mouse model indicated the nanoparticles could be passively targeting to lung and liver. CdHgTe/SiO₂ nanoparticles offer new perspectives for size dependent bio-dstribution studies in living body.

Indocyanine green (ICG) is an FDA-approved infrared chromophore used for various biomedical applications such as cardiac and hepatic function evaluation, and ophthalmic angiography. Despite its clinical applications, freely dissolved ICG binds non-specifically to various plasma proteins resulting in changes in its near infrared (NIR) emission properties and rapid elimination from the vasculature. To overcome these shortcomings, we have encapsulated ICG within polymeric nano-constructs composed of poly allylamine hydrochloride (PAH) cross-linked with di-sodium hydrogen phosphate (Na2HPO4). To optimize the photophysical properties of nano-encapsulated ICG (NE-ICG) for clinical imaging applications, we report measurements of fluorescent quantum yield (φ) of NE-ICG. Specifically, we constructed capsules of three different diameters (~130, ~240, and ~450 nm). Our preliminary results indicate that NE-ICG shows less quantum yield compared to freely-dissolved ICG. We determined that the 240 nm diameter capsule to have the highest φ and 450 nm diameter capsules to have the least φ at room temperature.

Different approaches have been reported in the recent years for the in vivo delivery and targeting of poorly soluble contrast agents and active ingredients in diseased tissues. In this context, we developed new lipid nanoparticles (Lipidots®) with size being easily varied from 25 to 120 nm. Lipidots® display numerous advantages: they are composed of low-cost and biocompatible lipids; they can be stored in injection-ready formulations for long duration; their manufacturing process is versatile and up-scalable. Several indocyanines have been efficiently encapsulated in the particles while retaining their spectroscopic properties, with emission wavelengths ranging from 500 to 820 nm. Thus, dye loaded-Lipidots® have been proved suitable for both in vitro and in vivo applications. To better understand Lipidots®' behavior in biological systems, formulations based on Förster Resonance Energy Transfer (FRET) have been studied. Different pairs of the selected indocyanines were co-encapsulated and calculations proved that transfer efficiency within nanoparticles (i) behaves as in a continuous medium; (ii) depends on local acceptor concentration. Thanks to the local dye concentration dependence of FRET, these formulations are used to understand where and when the particles are assimilated in biological systems. FRET-based Lipidots® contrast agents are also promising tools to enhance imaging contrast in vivo by making a clear difference between circulating and uptaken particles.

We present a new family of dipyrrins, whose spectral properties are tunable over the visible/near infrared range by way of annealing the pyrrolic residues with external aromatic fragments. Complexes of the π-extended with many metal ions were found to be highly fluorescent, and their fluorescence is modulated depending on the mode of the metal coordination. Structural and spectroscopic data were consolidated on the basis of the Kasha's exciton coupling theory, suggesting rational pathways to practically useful fluorogenic dipyrrin-based ligands. Water-soluble dendritic π- extended dipyrrin BDP-1 was prepared and evaluated as a fluorescent sensor for Zn²⁺. BDP-1 shows micromolar binding affinity for Zn²⁺ and high selectivity compared to Ca²⁺, Mg²⁺ and many other metal ions.

Accurate measurement of glomerular filtration rate (GFR) at the bedside is highly desirable in order to assess renal function in real-time, which is currently an unmet clinical need. In our pursuit to develop exogenous fluorescent tracers as GFR markers, various hydrophilic derivatives of 3,6-diaminopyrazine-2,5-dicarboxylic acid with varying molecular weights and absorption/emission characteristics were synthesized. These include polyhydroxyalkyl based small molecules and poly(ethylene glycol) (PEG) substituted moderate molecular weight compounds, which were further sub-grouped into analogs having blue excitation with green emission, and relatively longer wavelength analogs having green excitation with orange emission. Lead compounds were identified in each of the four classes on the basis of structure- activity relationship studies, which included in vitro plasma protein binding, in vivo urine recovery of administered dose, and in vivo optical monitoring. The in vivo optical monitoring experiments with lead candidates have been correlated with plasma pharmacokinetic (PK) data for measurement of clearance and hence GFR. Renal clearance of these compounds, occurring exclusively via glomerular filtration, was established by probenecid blocking experiments. The renal clearance property of all these advanced candidates was superior to that of the iothalamate, which is currently an accepted standard for the measurement of GFR.

A new class of chemiluminescent and fluorescent dyes and dye-doped nanoparticles can be stored at zero degrees and then made to emit near-infrared light by warming to body temperature (no chemical or electrical stimulus is needed). In vivo chemiluminescence imaging permits identification of target sites that are five times deeper than planar fluorescence imaging. A new imaging paradigm employs the dual modality probes first in high contrast chemiluminescence mode to locate relatively deep anatomical locations in vivo and subsequently in fluorescent mode to identify the microscopic targets within thin histopathology sections taken from the same specimen.

Indispensable for fluorescence imaging are highly specific and sensitive molecular probes that absorb and emit in the near infrared (NIR) spectral region and respond to or target molecular species or processes. Here, we present approaches to targeted fluorescent probes for in vivo imaging in the intensity and lifetime domain exploiting NIR dyes. Screening schemes for the fast identification of suitable fluorophores are derived and design criteria for highly emissive optical probes. In addition, as a signal amplification strategy that enables also the use of hydrophobic NIR fluorophores as fluorescent reporters, first steps towards versatile strategies for the preparation of NIR-fluorescent polymeric particles are presented that can be utilized also for the design of targeted and analyte-responsive probes.

We present a novel, dual modality gadolinium based MRI/near-infrared optical probe. Utilizing a fluorescent dye as a scaffold with attached Gd-chelating moiety, we demonstrated a substantial shortening of T1 relaxation time of water protons in vitro. The probe was compared to the commonly used MRI Gd-based contrast agents Magnevist® and Multihance® and showed superior contrast properties. The enhancement was due to strong albumin binding of the hydrophobic fluorophore and overall rigidification of the contrast agent. Due to the near-infrared optical properties of the probe and excellent MRI activity the proposed construct can be potentially utilized as a dual probe in multimodal MRI/NIR optical imaging.

The lymphatic system plays an important role in cancer cell dissemination; however whether lymphatic drainage pathways and function change during tumor progression and metastasis remains to be elucidated. In this report, we employed a non-invasive, dynamic near-infrared (NIR) fluorescence imaging technique for functional lymphatic imaging. Indocyanine green (ICG) was intradermally injected into tumor-free mice and mice bearing C6/LacZ rat glioma tumors in the tail or hindlimb. Our imaging data showed abnormal lymphatic drainage pathways and reduction/loss of lymphatic contractile function in mice with lymph node (LN) metastasis, indicating that cancer metastasis to the draining LNs is accompanied by transient changes of the lymphatic architectural network and its function. Therefore, functional lymphatic imaging may provide a role in the clinical staging of cancer.

Fluorophore concentration, the surrounding microenvironment, and photobleaching greatly influence the fluorescence intensity of a fluorophore, increasing the difficulty to directly observe micro-environmental factors such as pH and oxygen. However, the fluorescence lifetime of a fluorophore is essentially independent of both the fluorophore concentration and photobleaching, providing a viable alternative to intensity measurements. The development of fluorescence lifetime imaging (FLI) allows for the direct measurement of the microenvironment surrounding a fluorophore. Pt-porphyrin is a fluorophore whose optical properties include a very stable triplet excited state. This energy level overlaps strongly with the ground triplet state of oxygen, making the phosphorescent lifetime directly proportional to the surrounding oxygen concentration. Initial experiments using this fluorophore involved the use of individual microwells coated with the porphyrin. Cells were allowed to enter the micro-wells before being sealed to create a diffusionally isolated volume. The decrease in the extracellular oxygen concentration was observed using FLI. However, this isolation technique provides only the consumption rate but cannot indicate the subcellular oxygen distribution. To improve upon this, live macrophages are loaded with the porphyrin and the fluorescence lifetime determined using a Lambert Instruments Lifa-X FLI system. Initial results indicate that an increase in subcellular oxygen is observed upon initial exposure to invasive bacteria. A substantial decrease in oxygen is observed after about 1 hour of exposure. The cells remain in this deoxygenated state until the bacteria are removed or cell death occurs.

Stem cells can differentiate into multiple cell types, and thus have the potential to be used for tissue repair and regeneration. However, the participation of stem cells in wound repair and neovascularization is not well understood. As a result, there is a need to monitor and track stem cells in vivo in order to obtain a better understanding of the mechanisms of the wound healing response. Noninvasive, long-term imaging is ideal in order to track stem cells within a single animal model. Thus, we are interested in developing an imaging approach to track gold nanoparticle loaded mesenchymal stem cells (MSCs) in vivo after delivery via a hydrogel. This study assessed the effect on cell function of loading MSCs with gold nanoparticles. We examined the loading of MSCs with gold nanoparticles of various sizes and surface coatings using darkfield microscopy. We also examined the effect of nanoparticle loading on cell viability, proliferation, and differentiation. The feasibility of imaging nanoparticle loaded MSCs was examined by assessing cell viability and MSC tubulogenesis following laser irradiation. Our results demonstrate that loading MSCs with gold nanoparticles does not compromise cell function. These findings lend to the possibility of imaging MSCs in vivo with optical imaging.

Optically active nanoparticles are widely pursued as exogenous chromophores in diagnostic imaging and phototherapeutic applications. However, the blood circulation time of nanoparticles remains limited due to the rapid clearance of the nanoparticles by reticuloendothelial system (RES). Coating with Polyethylene glycol (PEG) is a strategy to extend the circulation time of nanoparticles. Here, we report synthesis and cellular studies of polymeric-based nanocapsules loaded with Indocyanine green (ICG), an FDA approved near-infrared dye, and coated with PEG molecules of various molecular weights through reductive amination. We report the effect of PEG's molecular weight on the uptake of these nanocapsules by human spleen macrophages and hepatocytes using flow cytometry. Our results indicate that the phagocytic content of PEGylated nanocapsules in human spleen macrophages was reduced as compared to uncoated nanocapsules. Among PEGylated nanocapsules, low molecular weight (5000 Da) PEG-coated nanocapsules displayed lower intracellular uptake by spleen macrophages than high molecular weight (30,000 Da) PEG-coated nanocapsules for up to 90 minutes. Encapsulation within the polymeric nanocapsules reduced the hepatic content of ICG with normal human hepatocytes for up to two hours, while the molecular weight of PEG did not have a statistically significant effect on the content of the nanocapsules in liver cells. Our results suggest that reduced uptake of nanocapsules by RES cells can result in prolonged blood circulation time of these nanoconstructs.

We give new insight into multifunctional nanoparticles with light extinction in the therapeutic window, optical stability even on aggregation, as well as possibility of bio-conjugation. The optical response of these particles rests on gold nanorods, which interact with near infrared (NIR) light via plasmonic oscillations, i.e. a boundary effect which depends on all physiochemical conditions at the interface with their environment. Therefore their feasibility for biomedical applications is challenged by a poor definition of their dispersion medium, aggregation (e.g. inside endocytic vesicles) and shape transformations, which typically occur in the biological sample and under excitation and jeopardize their optical features. Here silanization of the gold nanorods is proposed as one effective solution to overcome these issues. A shell of porous silica confers isolation from the local environment and additional stability, and also proves suitable for PEGylation and bio-conjugation with e.g. biological macromolecules. In particular we engineer models of aggregation of these particles, in order to investigate its principal effect on their optical response. While in the absence of silica gold nanorods undergo substantial degradation of their plasmon oscillations, silanization proves excellent to maintain pristine optical properties even after critical flocculation.

No single clinical imaging modality has the ability to provide both high resolution and high sensitivity at the anatomical, functional and molecular level. Synergistically integrated detection techniques overcome these barriers by combining the advantages of different imaging modalities while reducing their disadvantages. We report the development of protein nanospheres optimized for enhancing MRI, CT and US contrast while also providing high sensitivity optical detection. Transferrin protein nanospheres (TfpNS), silicon coated, doped rare earth oxide and rhodamine B isothiocyanate nanoparticles, Si⊂Gd₂O₃:Eu,RBITC, (NP) and transferrin protein nanospheres encapsulating Si⊂Gd₂O₃:Eu,RBITC nanoparticles (TfpNS-NP) were prepared in tissue-mimicking phantoms and imaged utilizing multiple cross-sectional imaging modalities. Preliminary results indicate a 1:1 NP to TfpNS ratio in TfpNS-NP and improved sensitivity of detection for MRI, CT, US and fluorescence imaging relative to its component parts and/or many commercially available contrast agents.

Two-Photon luminescence (TPL) from gold nanorods shows considerable potential in biological imaging for high resolution, low photo-damage, tunable near infra-red (NIR) longitudinal band, polarization dependence, ability to conjugate to bio-molecules and low toxicity. Here we demonstrate the application of gold nanorods as TPL imaging agents by studying the gold nanorods taken up by Madin-Darby canine kidney (MDCK) cells using both confocal imaging and fluorescence lifetime imaging microscopy (FLIM). The characteristic luminescence lifetime of gold nanorods is found to be less than 100 ps, which can be used to distinguish gold nanorods from other fluorescent labels and endogenous fluorophores in lifetime imaging.

We report the results of quantum mechanical investigations of the atomic structure and deformations of graphene nanoparticle undergoing axial compression. We applied the tight-binding (TB) method. Our transferable tightbinding potential correctly reproduced tight-binding changes in the electronic configuration as a function of the local bonding geometry around each carbon atom. The tight-binding method applied provided the consideration and calculation of the rehybridization between σ- and π-orbitals. To research nanoribbons using tight-binding potential our own program was used. We adapted TB method to be able to run the algorithm on a parallel computing machine (computer cluster). To simulate axial compression of graphene nanoparticles the atoms on the ends were fixed on the plates. The plates were moved towards each other to decrease the length at some percent. Plane atomic network undergoing axial compression became wave-like. The amplitude of wave and its period were not constant and changed along axis. This is a phase transition. The strain energy collapse occurs at the value of axial compression 0.03-0.04. The strain energy increased up to the quantity compression 0.03, then collapsed sharply and decreased. So according to our theoretical investigation, the elasticity of graphene nanoparticles is more than the elasticity of nanotubes the same width and length. The curvature of the atomic network because of compression will decrease the reactivity of graphene nanoparticles. We have calculated the atomic structure and electronic structure of the compression graphene nanopaticle at each step of strain of axial compression. We have come to the conclusion that the wave-like graphenes adsorbing protein and nucleic acid are the effective nanosensors and bionanosensors.

The continuously expanding number of fluorescent probes developed for molecular imaging in vivo requires new instruments, more flexible and with higher quantification power. Responding to those requirements we propose a new instrument: it combines the sensitivity of time correlated single photon detection with the extended spectral coverage of a pulsed supercontinuum laser in a sensitive and flexible time-domain platform for in vivo molecular imaging in small animals. The performance of the system is demonstrated on a case study, using NEO-STEM-PMSR50- PEG fluorescent silica nanoprobes and sequential imaging of CD-1 nude mice.

Far-field super-resolution microscopy is a rapidly emerging method that is opening up opportunities for biological imaging beyond the optical diffraction limit. We have implemented a Stimulated Emission Depletion (STED) microscope to image single dye, cell, and tissue samples with 50-80 nm resolution. First, we compare the STED performance imaging single molecules of several common dyes and report a novel STED dye. Then we apply STED to image planar cell polarity protein complexes in intact fixed Drosophila tissue for the first time. Finally, we present a preliminary study of the centrosomal protein Cep164 in mammalian cells. Our images suggest that Cep164 is arranged in a nine-fold symmetric pattern around the centriole, consistent with findings suggested by cryoelectron tomography. Our work demonstrates that STED microscopy can be used for superresolution imaging in intact tissue and provides ultrastructural information in biological samples as an alternative to immuno-electron microscopy.

The paper will introduce a compression algorithm that will use based number systems beyond the fundamental standard of the traditional binary, or radix 2, based system in use today. A greater level of compression is noted in these radix based number systems when compared to the radix 2 base as applied to a sequential strings of various information. The application of this comrpession algorithm to both random and non-random sequences for compression will be reviewed in this paper. The natural sciences and engineering applications will be areas covered in this paper.

Caged compound is one of the most powerful tools for spatiotemporal control of biomolecules in cells, which can be activated by irradiation of light. However, ultra violet light, which is required for activation of caged compounds, can damage cells and has poor permeability into tissues. In addition, invisibility of caged compounds makes it difficult to tell distribution of released small molecules. At the conference, we will describe the development of novel caging group and new caged compounds which are fluorescently visible and efficiently activatable with green light. We have found that boron dipyrromethene (BODIPY), known as a widely used fluorophore, is a potential caging group for phenol, carboxyl acid and amine, which can be photolized with irradiation of green light at around 500 nm wavelength. Based on the novel photo-reaction of 4-phenoxy BODIPY derivatives, we have developed caged histamine and applied it to HeLa cells. Photo-irradiation to cells in the presence of caged histamine induced transient increase of calcium ion in cytosol, which was specifically inhibited with pyrilamine, a H1 blocker. Also, we showed that BODIPY-caged compound can be utilized in vivo with tissue-permeable 500 nm green light.