Noncontact recognition of fluorescently labeled objects in deep tissue via a novel optical light beam arrangement

Abstract

To date, few optical imaging systems are available in clinical practice to perform noninvasive measurements transcutaneously. Instead, functional imaging is performed using ionizing radiation or intense magnetic fields in most cases. The applicability of fluorescence imaging (e.g., for the detection of fluorescently labeled objects, such as tumors) is limited due to the restricted tissue penetration of light and the required long exposure time. Thus, the development of highly sensitive and easily manageable instruments is necessary to broaden the utility of optical imaging. To advance these developments, an improved fluorescence imaging system was designed in this study that operates on the principle of noncontact laser-induced fluorescence and enables the detection of fluorescence from deeper tissue layers as well as real-time imaging. The high performance of the developed optical laser scanner results from the combination of specific point illumination, an intensified charge-coupled device (ICCD) detector with a novel light trap, and a filtering strategy. The suitability of the laser scanner was demonstrated in two representative applications and an in vivo evaluation. In addition, a comparison with a planar imaging system was performed. The results show that the exposure time with the developed laser scanner can be reduced to a few milliseconds during measurements with a penetration depth of up to 32 mm. Due to these short exposure times, real-time fluorescence imaging can be easily achieved. The ability to measure fluorescence from deep tissue layers enables clinically relevant applications, such as the detection of fluorescently labeled malignant tumors.

Targeted 64Cu‐labeled gold nanoparticles for dual imaging with positron emission tomography and optical imaging

“…Furthermore, PEGylation of the AuNPs leads to a higher bioavailability as it hinders in vivo formation of a protein corona around the AuNP. 14,15 Therefore, target-specific AuNPs can be developed and functionalized with small molecules, 5 antibodies, 16 peptides, 17 natural products, 18,19 near-infrared (NIR) dyes, 20,21 radionuclides, 22,23 and magnetic resonance imaging (MRI)-relevant metals. 24 Of the various diagnostic applications, radiolabeled nanoparticles for multimodal imaging have received special attention 25,26 as they represent an important possibility to create imaging agents for specific and highly sensitive target visualization.…”

Molecule Sensitive Optical Imaging and Monitoring Techniques—A Review of Applications in Micro-Process Engineering

“…This method is not supposed to replace common technologies, like computer tomography (CT) or magnetic resonance imaging (MRI), but it is meant to supplement the highlighting of the malignant areas to reduce time that is needed with common technologies. The advantages of this method, compared to common technologies, are its greatly increased measurement rate and low price [28].…”

αvβ3-Specific Gold Nanoparticles for Fluorescence Imaging of Tumor Angiogenesis

“…Therefore, ultra-small target-specific AuNPs can be developed and functionalized with small molecules [ 11 ], antibodies [ 22 ], peptides [ 23 ], and natural products [ 24 , 25 ]. For molecular imaging, AuNPs can be functionalized with near-infrared dyes [ 26 , 27 ], with radionuclides like fluorine-18, copper-64 or gallium-68 for positron emission tomography (PET) [ 28 , 29 , 30 , 31 , 32 ], and with Magnetic Resonance Imaging (MRI)-relevant metals like gadolinium [ 33 , 34 ]. Additionally, their therapeutic application [ 35 ], and particularly their ability to be applicable as a radiosensitizer by Auger-Meitner electron (AME) emission induced by external gamma activation [ 36 , 37 , 38 ] or β - emission of 412 keV electrons induced by neutron activation of natural 197 Au generating [ 198 Au]AuNPs [ 23 , 25 , 39 , 40 , 41 ] are of special interest.…”