Dual-Labelling Strategies for Nuclear and Fluorescence Molecular Imaging: Current Status and Future Perspectives

Abstract

Molecular imaging offers the possibility to investigate biological and biochemical processes non-invasively and to obtain information on both anatomy and dysfunctions. Based on the data obtained, a fundamental understanding of various disease processes can be derived and treatment strategies can be planned. In this context, methods that combine several modalities in one probe are increasingly being used. Due to the comparably high sensitivity and provided complementary information, the combination of nuclear and optical probes has taken on a special significance. In this review article, dual-labelled systems for bimodal nuclear and optical imaging based on both modular ligands and nanomaterials are discussed. Particular attention is paid to radiometal-labelled molecules for single-photon emission computed tomography (SPECT) and positron emission tomography (PET) and metal complexes combined with fluorescent dyes for optical imaging. The clinical potential of such probes, especially for fluorescence-guided surgery, is assessed.

Exploring the Potential of Nanogels: From Drug Carriers to Radiopharmaceutical Agents

“…These areas have significant clinical potential. [50,259] However, the use of nanogels is virtually unstudied here.…”

“…PET is used when a radionuclide emits positrons (𝛽 + ), whereas SPECT is used when a radionuclide emits gamma radiations. [48][49][50]175,178] The unique advantages that nuclear imaging techniques offer are quantification of the pharmacological behavior of radiolabeled agents, superior sensitivity (10 −10 -10 −12 m) and the unlimited penetration depth in tissues in comparison to other imaging modalities. A rotating gamma camera statistically detects the events of gamma photons of a certain energy level.…”

“…It is worth highlighting that nuclear techniques in particular allow quantitative data on the pharmacokinetic properties of radiolabeled nanomaterials, as well as release protocols of entrapped guest compounds. [45][46][47][48][49][50] This has led to intensive studies of in vitro and in vivo properties of nanogels using radiolabels, particularly in recent times.…”

Pre- and Intraoperative Visualization of GRPR-Expressing Solid Tumors: Preclinical Profiling of Novel Dual-Modality Probes for Nuclear and Fluorescence Imaging

“…Another important factor in achieving maximum image contrast with both imaging modalities is dose. A common challenge is to adapt the dose to match the sensitivity of both imaging techniques [ 35 , 36 ]. Surprisingly, the effect of administering increasing doses was observed best in the clearance pathway; liver uptake was more pronounced.…”

Targeting mucins for fluorescence-guided surgery of pancreatic cancer

“…Surgeons rely on their tactile and visual skills to identify and resect the tumor from the surrounding normal and fibrotic tissue. 5,7,[10][11][12][13][14][15][16] While surgeons are highly qualified, the presence of fibrotic tissue and disease progression increases the challenges in obtaining a complete tumor resection. 5,[17][18][19] Up to 60% of patients that undergo surgical resection develop recurrent disease within 2 years as a result of microscopic tumor lesions remaining after surgery.…”