β-CYCLODEXTRIN AS CARRIER FOR DIFFERENT GUEST MOLECULES IN BIOAPPLICATIONS – A MINIREVIEW ON THE THERMAL COMPLEXATION STUDIES BY DIFFERENTIAL SCANNING CALORIMETRY

The history of cyclodextrins dates back to the end of the 19th century, when in 1891, Antoine Villiers observed the enzymatic effect of different carbohydrates, with emphasis on the butyric ferment Bacillus amylobacter (Clostridium butyricum), on potato starch. Villiers had no idea of the impact and large number of applications his discovery would generate over the next century. The most common cyclodextrins include six, seven and eight glucose units (αCD, βCD and γCD) and are generally regarded as safe, especially βCD, by the Food and Drug Administration (FDA, USA). Due to their unique structure, cyclodextrins can form inclusion complexes with a vast variety of guest molecules. The properties of the native cyclodextrins can be improved by synthesizing derivatives, depending on the desired application field. Nowadays, cyclodextrin derivatives are more than 11.000. From a practical standpoint, the degradation of cyclodextrin inclusion complexes is studied by thermogravimetric analysis (TGA), however providing information only on mass change. Differential scanning calorimetry (DSC) method reveals (changes in) other transitions as well, evidenced in the selected representative literature examples and discussed in this minireview.