Rational chemical design of the next generation of molecular imaging probes based on physics and biology: mixing modalities, colors and signals

Abstract

In recent years, numerous in vivo molecular imaging probes have been developed. As a consequence, much has been published on the design and synthesis of molecular imaging probes focusing on each modality, each type of material, or each target disease. More recently, second generation molecular imaging probes with unique, multi-functional, or multiplexed characteristics have been designed. This critical review focuses on (i) molecular imaging using combinations of modalities and signals that employ the full range of the electromagnetic spectra, (ii) optimized chemical design of molecular imaging probes for in vivo kinetics based on biology and physiology across a range of physical sizes, (iii) practical examples of second generation molecular imaging probes designed to extract complementary data from targets using multiple modalities, color, and comprehensive signals (277 references).

Enabling Photon Upconversion and Precise Control of Donor–Acceptor Interaction through Interfacial Energy Transfer

“…Next, we examined the feasibility of realizing photon upconversion through an IET approach with 808 nm excitation, which shows a greater advantage in diverse biological applications due to the much lower absorption of OH − in comparison to the 980 nm wavelength 12. In this case, the Yb 3+ ‐sensitized upconversion systems are useless due to the lack of spectral response to the excitation at around 800 nm (Figure S12, Supporting Information).…”

Multiplexed imaging for diagnosis and therapy

“…In the advancing era of precision and personalised medicine, the role of multiplexing is not only essential; it is evolving. Echoing several themes 32,33,41 , this section surveys applications, challenges and advances in several of the most clinically relevant examples of multiplexed-imaging strategies, and includes clinically ubiquitous approaches in modern biomedical imaging as well as strategies at the forefront of the field, but not yet in widespread clinical use.…”

“…Herein, characteristic ultraviolet-blue CR is absorbed by a fluorophore and re-emitted at lower NIR-visible frequencies, enhancing tissue penetration and facilitating detection, and therefore increasing the utility of CL in the clinic. This phenomenon, known as Cerenkov radiation energy transfer (CRET), is an area of active research 32,[84][85][86] . However, in order to transition CRET into clinical practice, PET/CRET-compatible agents will need to be approved and validated.…”

“…The selection of complementary information using distinct imaging channels of transmission can lend incredible value in delineating and characterising the multiple features of tumours by yielding a more comprehensive pathological view of tumour structure and function [32][33][34][35][36][37][38][39][40] . Traditionally, in the case of PET-MR, MR provides the anatomic correlation for the quantitative functional information supplied by PET, leveraging the advantages of both the PET and MR components to provide a sensitive and detailed spatial map of a lesion.…”

A concise review of magnetic resonance molecular imaging of tumor angiogenesis by targeting integrin αvβ3 with magnetic probes

“…Therefore, MRI has no limitation for tissue penetration. 29 Moreover, compared to PET and SPECT, MRI does not use ionizing radiation and offers higher resolution and soft tissue contrast. In addition, MRI allows for multiparametric imaging in which T1, T2, and diffusion-weighted images (DWI) are obtained in one session, each reflecting a different tissue signal.…”