Cyclodextrins are widely used excipients, composed of glucopyranose units with a cyclic structure. One of their most important properties, is that their inner cavity is hydrophobic, while their surface is hydrophilic. This enables them for the complex formation with lipophilic molecules. They have several applications in the pharmaceutical field like solubility enhancers or the building blocks of larger drug delivery systems. On the other hand, they have numerous effects on cells or biological barriers. In this review the most important properties of cyclodextrins and cyclodextrin-based drug delivery systems are summarized with special focus on their biological activity.

Cyclodextrins are high molecular weight, hydrophilic, cyclic, non-reducing oligosaccharides, applied as excipients for the improvement of the solubility and permeability of insoluble active pharmaceutical ingredients. On the other hand, beta-cyclodextrins are used as cholesterol sequestering agents in life sciences. Recently, we demonstrated the cellular internalization and intracellular effects of cyclodextrins on Caco-2 cells. In this study, we aimed to further investigate the endocytosis of (2-hydroxylpropyl)-beta-(HPBCD) and random methylated-beta-cyclodextrin (RAMEB) to test their cytotoxicity, NF-kappa B pathway induction, autophagy, and lysosome formation on HeLa cells. These derivatives were able to enter the cells; however, major differences were revealed in the inhibition of their endocytosis compared to Caco-2 cells. NF-kappa B p65 translocation was not detected in the cell nuclei after HPBCD or RAMEB pre-treatment and cyclodextrin treatment did not enhance the formation of autophagosomes. These cyclodextrin derivates were partially localized in lysosomes after internalization.

The application of 2-hydroxypropyl-beta-cyclodextrin (HPBCD) in the treatment of the rare cholesterol and lipid storage disorder Niemann–Pick disease type C opened new perspectives in the development of an efficient therapy. Even if the systemic administration of HPBCD was found to be effective, its low permeability across the blood–brain barrier (BBB) limited the positive neurological effects. Nevertheless, the cellular interactions of HPBCD with brain capillary endothelial cells have not been investigated in detail. In this study, the cytotoxicity, permeability, and cellular internalization of HPBCD on primary rat and immortalized human (hCMEC/D3) brain capillary endothelial cells were investigated. HPBCD shows no cytotoxicity on endothelial cells up to 100 µM, measured by impedance kinetics. Using a fluorescent derivative of HPBCD (FITC-HPBCD) the permeability measurements reveal that on an in vitro triple co-culture BBB model, FITC-HPBCD has low permeability, 0.50 × 10⁻⁶ cm/s, while on hCMEC/D3 cell layers, the permeability is higher, 1.86 × 10⁻⁵ cm/s. FITC-HPBCD enters brain capillary endothelial cells, is detected in cytoplasmic vesicles and rarely localized in lysosomes. The cellular internalization of HPBCD at the BBB can help to develop new strategies for improved HPBCD effects after systemic administration.

Cyclodextrin-based micro- and nanocarriers are increasingly being explored as versatile tools for improving the stability and delivery of probiotic microorganisms, addressing persistent challenges such as acid and bile sensitivity, oxidative stress, and processing-related losses. A wide range of micro- and nano-encapsulation strategies, including spray drying, extrusion, coacervation, freeze-drying, and electrospinning, have been developed to enhance probiotic viability and gastrointestinal performance. Within this technological landscape, cyclodextrins offer distinctive advantages due to their ability to form multifunctional carrier matrices and stabilize sensitive bioactive components through both inclusion and non-inclusion interactions. Beyond their role as formulation excipients, emerging evidence indicates that certain cyclodextrins may also exhibit prebiotic-like properties, selectively modulating gut microbiota composition and metabolic activity. This combination of carrier functionality and potential biological activity suggests a conceptual framework for synbiotic design in which cyclodextrins could both protect probiotics and influence the intestinal environment following release. Advances in cyclodextrin-based hydrogels, nanosponges, and hybrid polymer systems further illustrate opportunities for colon-targeted delivery, microbiota-responsive degradation, and controlled release; however, most probiotic-specific applications remain at an exploratory stage. Key challenges related to large-scale manufacturing, microbial viability, safety assessment, and regulatory harmonization remain unresolved. Rather than presenting a finalized technology, this review integrates evidence from food science, pharmaceutical research, and microbiome studies to highlight cyclodextrin-enabled probiotic formulation as an emerging research domain. By delineating current opportunities and limitations, the work aims to stimulate interdisciplinary investigation into the potential role of cyclodextrins in future probiotic and synbiotic systems

A SARS-CoV-2 vírus 2019 év végi felbukkanása óta nagyszámú terápiás stratégia látott napvilágot a kórokozó miatt sokszor nagyon súlyos állapotba kerülő betegek kezelésére. Ahogy egyre több ismeret áll rendelkezésre a vírusról, annál jobban lehet a terápia kapcsán felmerülő ötleteket is finomítani. A ciklodextrinek már régóta ismert molekulák a gyógyszeriparban, különleges szerkezetükből adódóan sokféleképpen felhasználhatók gyógyszerfejlesztés során. Tekintettel a jelenlegi pandémiás helyzetre fontosnak gondoltuk összefoglalni, hogy a kutatócsoportunk által már évek óta vizsgált ciklodextrin molekuláknak milyen szerepe lehet a COVID-19 betegség terápiájában. Az elvégzett irodalmi kutatómunka során sok érdekes elméletet és ígéretes fejlesztést találtunk.

A ciklodextrinek széles körben alkalmazott segédanyagok a lipofil gyógyszerek vízoldhatóságának és biológiai hasznosíthatóságának növelésére. Kutatócsoportunk korábban kimutatta, hogy a ciklodextrinek endocitózissal képesek bejutni a Caco-2 intesztinális epitél sejtekbe, azonban a különböző sejtek esetén történő celluláris internalizációt és az intracelluláris hatásait eddig még nem vizsgálták. Mindemellett a 2-hidroxi-propil-béta-ciklodextrin (HPBCD) koleszterin komplexáló tulajdonságának köszönhetően a C típusú Niemann Pick szindróma kezelésére alkalmazott molekula. Munkánk célja a HPBCD celluláris internalizációjának és a sejtekben található lizoszómákra gyakorolt hatásának vizsgálata és összehasonlítása Caco-2 intesztinális epitél, HeLa méhnyak epitél és hCMEC/D3 agyi endotél sejteken.