Optical and magnetic resonance imaging approaches for investigating the tumour microenvironment: state-of-the-art review and future trends

Abstract

The tumour microenvironment (TME) strongly influences tumorigenesis and metastasis. Two of the most characterized properties of the TME are acidosis and hypoxia, both of which are considered hallmarks of tumours as well as critical factors in response to anticancer treatments. Currently, various imaging approaches exist to measure acidosis and hypoxia in the TME, including magnetic resonance imaging (MRI), positron emission tomography and optical imaging. In this review, we will focus on the latest fluorescent-based methods for optical sensing of cell metabolism and MRI as diagnostic imaging tools applied both in vitro and in vivo. The primary emphasis will be on describing the current and future uses of systems that can measure intra- and extra-cellular pH and oxygen changes at high spatial and temporal resolution. In addition, the suitability of these approaches for mapping tumour heterogeneity, and assessing response or failure to therapeutics will also be covered.

Composition‐dependent multivalency of peptide–peptide interactions revealed by tryptophan‐scanning mutagenesis

“…A change with the composition and concentration of solution buffer can result in a fluctuation in the dielectric permittivity of medium, and thus change the magnitude of van der Waals interactions. Such efforts on environment‐dependence of interpeptide interactions should be rigorously pursued in future efforts for developing peptide‐enabled delivery systems towards tumor microenvironments 35–37 …”

Probing single cell fermentation flux and intercellular exchange networks via pH-microenvironment sensing and inverse modeling

“…We developed fluorescent pH-sensing nanofiber scaffolds composed of optical pHsensors microparticles, highly suitable for monitoring pH changes in the surrounding environment [28][29][30][31][32][33][34][35], and polycaprolactone (PCL) nanofibers, because of their processability, biocompatibility, biodegradability, and mechanical stability [36][37][38][39][40][41]. The morphology of the hybrid pH-sensing fibers was studied in detail by means of scanning electron microscopy (SEM) and CLSM.…”

Fabrication of SEBS Block Copolymer-Based Ultrasound Phantom Containing Mimic Tumors for Ultrasound-Guided Needle Biopsy Training

“…Some of these studies have determined that a tumor can be destroyed or significantly reduced in size, potentially saving or extending a person's life. Accurate tumor diagnosis is essential for effective cancer treatment, and can be accomplished using welldeveloped medical imaging techniques such as magnetic resonance imaging, computed tomography and ultrasound (US) imaging (Moskovitch et al 2010;Meloni et al 2015;Prarsad et al 2021). The majority of tumors, however, are found deep within human soft tissues, making them difficult to reach.…”