D-galactose, a simple natural compound, has been investigated as a powerful scaffold for drug delivery, diagnostics, and theranostics due to its distinctive properties and interactions with specific cell receptors. In the field of drug delivery, galactose functions as a ligand to selectively target cells expressing galactose receptors, such as hepatocytes, macrophages, and specific cancer cells. The direct attachment of galactose to the main drug or to drug-loaded nanoparticles or liposomes enhances cellular uptake, thereby improving drug delivery to the intended target cells. Galactose has also been found to be useful in diagnostics. Specifically, diagnostic tests based on galactose, such as the galactose elimination capacity test, are utilized to evaluate liver function and assess liver disease as well as hepatic functional reserve. Additionally, galactose-based theranostic agents can be designed by combining drug delivery and diagnostic capabilities. This review is an update of our previous review concerning the broad spectrum of possibilities for exploiting D-galactose as a vector for prodrug design and the synthetic strategies that allow its realization, jointly in diagnostics and theranostics, to highlight the versatility of this interesting vector.

Arginase (ARG) is a binuclear manganese-containing metalloenzyme that can convert L-arginine to L-ornithine and urea and plays a key role in the urea cycle. It also mediates different cellular functions and processes such as proliferation, senescence, apoptosis, autophagy, and inflammatory responses in various cell types. In mammals, there are two isoenzymes, ARG-1 and ARG-2; they are functionally similar, but their coding genes, tissue distribution, subcellular localization, and molecular regulation are distinct. In recent decades, the abnormal expression of ARG-1 or ARG-2 has been reported to be increasingly linked to a variety of diseases, including cardiovascular disease, inflammatory bowel disease, Alzheimer’s disease, and cancer. Therefore, considering the current relevance of this topic and the need to address the growing demand for new and more potent ARG inhibitors in the context of various diseases, this review was conceived. We will provide an overview of all classes of ARG inhibitors developed so far including compounds of synthetic, natural, and semisynthetic origin. For the first time, the synthesis protocol and optimized reaction conditions of each molecule, including those reported in patent applications, will be described. For each molecule, its inhibitory activity in terms of IC₅₀ towards ARG-1 and ARG-2 will be reported specifying the type of assay conducted.

This work investigates the synthesis of polypeptoid nanoparticles through Ugi‐mediated polymerization‐induced self‐assembly (U‐PISA), combining aqueous Ugi four‐component polycondensation with PEG‐based stabilization. Polypeptoid nano‐objects were produced directly from amino acid‐derived building blocks via a one‐pot process under mild, open‐air conditions. The effects of PEG molar mass and feed composition on particle formation and morphology were systematically examined, providing access to tunable spherical and worm‐like nanostructures. The in situ formation of amphiphilic PEG‐polypeptoid species suggests that nanoparticle formation proceeds through a PISA‐like mechanism. However, the step‐growth nature of the Ugi polycondensation implies that both PEG‐functionalized and unconjugated polypeptoid chains may participate in nanoparticle assembly and stabilization. These results demonstrate that multicomponent polymerizations, such as Ugi polymerization, can be integrated into a PISA strategy, offering a simple route to polypeptoid nanoparticles with tunable morphologies and potential biomedical applications.