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Surgery is one of the most effective and widely used procedures in treating human cancers, but a major problem is that the surgeon often fails to remove the entire tumor, leaving behind tumor-positive margins, metastatic lymph nodes, and/or satellite tumor nodules. Here we report the use of a hand-held spectroscopic pen device (termed SpectroPen) and near-infrared contrast agents for intraoperative detection of malignant tumors, based on wavelength-resolved measurements of fluorescence and surface-enhanced Raman scattering (SERS) signals. The SpectroPen utilizes a near-infrared diode laser (emitting at 785 nm) coupled to a compact head unit for light excitation and collection. This pen-shaped device effectively removes silica Raman peaks from the fiber optics and attenuates the reflected excitation light, allowing sensitive analysis of both fluorescence and Raman signals. Its overall performance has been evaluated by using a fluorescent contrast agent (indocyanine green, or ICG) as well as a surface-enhanced Raman scattering (SERS) contrast agent (pegylated colloidal gold). Under in vitro conditions, the detection limits are approximately 2-5 x [10.sup.-11] M for the indocyanine dye and 0.5-1 x [10.sup.-13] M for the SERS contrast agent. Ex vivo tissue penetration data show attenuated but resolvable fluorescence and Raman signals when the contrast agents are buried 5-10 mm deep in fresh animal tissues. In vivo studies using mice bearing bioluminescent 4T1 breast tumors further demonstrate that the tumor borders can be precisely detected preoperatively and intraoperatively, and that the contrast signals are strongly correlated with tumor bioluminescence. After surgery, the SpeetroPen device permits further evaluation of both positive and negative tumor margins around the surgical cavity, raising new possibilities for real-time tumor detection and image-guided surgery. 10.1021/ac102058k

Cypate-octreote peptide analogue conjugate (Cytate) was investigated as a prostate cancer receptor-targeted contrast agent. The absorption and fluorescence spectra of Cytate were ranged in the near-infrared 'tissue optical window.' Time-resolved investigation of polarization-dependent fluorescence emitted from Cytate in solution as well as in cancerous and normal prostate tissues was conducted. Polarization preservation characteristics of Cytate in solution and tissues were studied. Fluorescence intensity emitted from the Cytate-stained cancerous prostate tissue was round to be much stronger than that from the Cytate-stained normal prostate tissue, indicating more Cytate uptake in the former tissue type. The polarization anisotropy of Cytate contained in cancerous prostate tissue was found to be larger than that in the normal prostate tissue, indicating a larger degree of polarization preservation in Cytate-stained cancerous tissue. The temporal profiles of fluorescence from Cytate solution and from Cytate-stained prostate tissue were fitted using a time-dependent fluorescence depolarization model. The photoluminescence imaging of Cytate-stained cancerous and normal prostate tissues was accomplished, showing the potential of Cytate as a fluorescence marker for prostate cancer detection. OCIS codes: 300.6280, 110.3080.

The synthesis and characterization of a reversible T2 contrast agent consisting of cross-linked anionic dextran coated iron oxide nanoparticles covalently coupled to a light-sensitive spiropyran (SP)/merocyanine (MC) motif is described. The smart T2 agent has provided the advantage of reversibility that has enabled dynamic monitoring with MRI and the light responsiveness of the agent has indicated the potential to use them as MRI gene reporters for the luciferase expression system.

An effective new optical contrast agents is developed by describing the synthesis of porphyrazines (pzs) of the form [H.sub.2][pz([A.sub.4-n];[C.sub.n])] (A = peripheral heteroatom (S- and O-) R-groups and C is a fused, [bta],[bta]'-diisopropyloxynaphtho group). Emission from the oxygen-atom appended naphtho-pzs is observed within carcinoma cells, which has confirmed the cellular uptake and their potential use as optical agents.

The article explains the formation, as well as the evaluation of a new supramolecular lanthanide complex, which is shown to act as luminescent contract agent for various purposes. The Eu(III) emission of the complex is shown to be independent of the pH value and hence can be used for the imaging of the damaged bone structure.

Nanoassembled capsules (NACs) formed by using the MRI contrast agent GdDOT[P.sup.5-] in the internal polymer aggregate are described, the smaller of which has shown promise as potential MRI contrast agents. The greatest gains in relaxivity are observed for smaller NACs, for which water accessibility has remained high but molecular rotation of the [Gd.sup.3+] chelate is restricted.

The synthesis and characterization of Fe(III)-carboxylate nanoscale metal-organic frameworks (NMOFs) with the MIL-101 structure is reported. The potential use of the newly obtained NMOF-based nanodelivery vehicles for optical imaging and anticancer therapy is also demonstrated in vitro by using HT-29 human colon adenocarcinoma cells.

Superparamagnetic iron oxide particles in Resovist and SH U555C, used as magnetic resonance imaging contrast agents, are polydispersed and covered with a thick organic coating so that the average particle sizes are described with different definitions. The studies have shown that the transverse relaxation rate behavior is determined by the diameter of bare single-crystal magnetic particles having the particle-volume-weighted average volume and is affected by their thick organic coating.