Superstructure based on β-CD self-assembly induced by a small guest molecule

Abstract

The size, shape and surface chemistry of nanoparticles play an important role in cellular interaction. Thus, the main objective of the present study was the determination of the β-cyclodextrin (β-CD) self-assembly thermodynamic parameters and its structure, aiming to use these assemblies as a possible controlled drug release system. Light scattering measurements led us to obtain the β-CD’s critical aggregation concentration (cac) values, and consequently the thermodynamic parameters of the β-CD spontaneous self-assembly in aqueous solution: ΔaggGo = − 16.31 kJ mol−1, ΔaggHo = − 26.48 kJ mol−1 and TΔaggSo = − 10.53 kJ mol−1 at 298.15 K. Size distribution of the self-assembled nanoparticles below and above cac was 1.5 nm and 60–120 nm, respectively. The number of β-CD molecules per cluster and the second virial coefficient were identified through Debye’s plot and molecular dynamic simulations proposed the three-fold assembly for this system below cac. Ampicillin (AMP) was used as a drug model in order to investigate the key role of the guest molecule in the self-assembly process and the β-CD:AMP supramolecular system was studied in solution, aiming to determine the structure of the supramolecular aggregate. Results obtained in solution indicated that the β-CD’s cac was not affected by adding AMP. Moreover, different complex stoichiometries were identified by nuclear magnetic resonance and isothermal titration calorimetry experiments.

Electrospun nanofibers of polyCD/PMAA polymers and their potential application as drug delivery system

“…ITC results could also provide information about the molecular stoichiometries of both systems, in which more than one guest molecule interacts with a single βCD [43]. Similar superstructures have been observed for CD systems, and in these cases, the guest molecule acted as a glue between the inclusion complexes [36]. Other studies have described interactions between CD-based polymers and guest molecules and their use as a promising drug carriers using ITC [44,45] These results strongly suggest that polyCD can be used as a polymer for DDS for hydrophilic molecules such as PROP.…”

“…[36] and this result can be attributed to a greater possibility of forming hydrogen bonds between the polymer and water. Similar systems formed by polyrotaxanes, which consisted of α-cyclodextrin and poly(ethylene glycol) (PEG), showed values with the same order of magnitude in different types of solvent systems [37].…”

Modulation of size and viscosity of Ni/Zn ferrites: Effect of doping with βCD and chemical treatment with HNO3 and NaOH

“…As reported in literature, cyclodextrins have the ability of spontaneously self-assembly in supramolecular structures of nanometric size [15,16,42]. Moreover, it has been demonstrated that cyclodextrins form coordination complex with transition metals at high pH values (>12), in such a way that a covalent bond is formed between metal ions (Fe, Ni or Zn) and deprotonated ReOH group, i.e.…”

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“…[46] The cavity size of β-CD is more suitable than other CDs to encapsulate a wide range of molecules. [47,48] The use of β-CD on drug solubility, bioavailability, safety, stability, and as a carrier in drug formulation may be attained by the formation of inclusion complexes with drug molecules; in fact, the use of β-CD already has a long history in pharmacy. [49,50] β-CD consists of seven glucopyranose residues and is only moderately soluble in water because of intermolecular hydrogen bonding.…”