**Preface to "Cyclodextrin Chemistry and Toxicology"**

Cyclodextrins (CDs) are cyclic oligosaccharides composed of six (α-CD), seven (β-CD), or eight (γ-CD) D (+) - glucose units linked by α-1,4 bonds. They have found wide application in numerous fields which, thanks to their typical toroidal structure consisting of an apolar internal cavity and a polar external surface, allows the physical inclusion of a wide range of molecules. Cyclodextrins have been the subject of several books, reviews and articles. This testifies to the great interest in these molecules and their derivatives due to the extensive use in various fields, such as biotechnology, chemistry, green chemistry, analytical chemistry, pharmacy, administration of drugs and pharmaceutical excipients, biology, medicine and biomedicine, food and beverage industry, cosmetic formulations/fragrance stabilization, chromatography, catalysis, biotechnology, agrochemistry and the remediation of polluted sites.

This collection of articles, through eleven contributions and three reviews, provides an overview of the applications of cyclodextrins, implements the information regarding the use of cyclodextrins and their inclusion complexes, considering both experimental and theorists approaches and using various scientific and technological tools. Furthermore, the importance of understanding the mechanisms involved in the formation of the complexes and of the resulting advantages, together with their possible integration within different application areas, including those related to data communication, are underlined.

In particular, the published articles have clearly highlighted the dynamism and breadth of the sectors involved, as well as the variety of approaches to the use of CDs: as food supplements and nutraceuticals by studying the impact on the grain dough and on the properties of bread, the effect on the antiplatelet capacity of proteins, development of new formulations with greater solubility, bioavailability and stability, the administration of drugs. The drug concentration plays an important role in the interaction with drug carriers that influence the kinetics of the release process and the toxicological effects. The Molecular Dynamics simulations are useful for evaluating the bioeffects of β-cyclodextrin-based nanosponges on two-dimensional cell cultures, also discussing the study of the cyclodextrin-based nanosystems in targeted cancer therapy. One of the reviews introduces the advances in cyclodextrin (pCD) polymer research, including their synthesis and applications in analytical separation science, materials science and biomedicine. Another review summarizes and highlights the results obtained in the field of cyclodextrin-based contrast agents for medical imaging. Finally, new perspectives are presented in the use of cyclodextrins in textiles, as smart materials for microbial control.

As guest editor of the Special Issue "Cyclodextrin Chemistry and Toxicology", we would like to express our deep appreciation to all the authors whose valuable work has been published in this issue, thus contributing to the success of the Special Issue. Despite the presence on the market of numerous food, cosmetic and pharmaceutical formulations, cyclodextrins continue to attract the interest of both the academic community and the industry and we believe that the rapid evolution of the different sectors considered is moving further in interdisciplinary way in the near future, this will give birth to new discoveries and applications based on innovative scientific insights carrying further technological advances, demonstrating that cyclodextrins, for research, still have a lot of interest.
