Evaluation of temoporfin affinity to β-cyclodextrins assuming self-aggregation

[Display omitted] •mTHPC easily forms 1:2 inclusion complexes with β-CDs following 2 step mechanism.•Methylation of β-CD’s core enhances the affinity to mTHPC.•mTHPC aggregation reduce the binding constant of the first β-CD molecule.•Corrected binding constant values are several times higher than pr...

Full description

Saved in:
Bibliographic Details
Published in:Journal of photochemistry and photobiology. A, Chemistry. Chemistry., 2018-12, Vol.367, p.13-21
Main Authors: Yakavets, I., Lassalle, H.-P., Yankovsky, I., Ingrosso, F., Monari, A., Bezdetnaya, L., Zorin, V.
Format: Article
Language:English
Subjects:
Affinity
Agglomeration
Aggregation
Aqueous solutions
Binding
Binding constants
Circular dichroism
Cyclodextrin
Cyclodextrins
Equilibrium
Inclusion complexes
Life Sciences
Molecular dynamics
mTHPC
Photobiology
Photochemistry
Solubility
Supramolecular chemistry
β-Cyclodextrins
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:[Display omitted] •mTHPC easily forms 1:2 inclusion complexes with β-CDs following 2 step mechanism.•Methylation of β-CD’s core enhances the affinity to mTHPC.•mTHPC aggregation reduce the binding constant of the first β-CD molecule.•Corrected binding constant values are several times higher than previously reported.•High binding constants allow the use the β-CDs for mTHPC delivery in PDT. The interaction between the potent photosensitizer meta-tetrakis(3-hydroxyphenyl)chlorin (temoporfin, mTHPC) and a series of β-cyclodextrins (β-CDs) was investigated using spectroscopic analysis and molecular dynamics simulations. The possibility of improving its poor aqueous solubility with β-CDs was estimated by measuring both equilibrium solubility and association constants. Parameters of binding isotherms revealed that mTHPC strongly interacts with β-CD derivatives, forming 1:2 inclusion complexes in aqueous solution. We demonstrated that apparent binding constants strongly depend on mTHPC concentration due to the porphyrin self-aggregation. The estimated “correct” binding constants demonstrated that completely methylated β-CD exhibits the highest affinity (K = 1.1 × 107 M−1) as compared to randomly methylated β-CD (K = 7.1 × 105 M−1) and 2-hydroxypropyl substituted β-CD (K = 1.7 × 105 M−1). In fine, our results indicate that TM-β-CD should be considered as a potent vector for mTHPC targeted delivery.
ISSN:1010-6030
1873-2666
DOI:10.1016/j.jphotochem.2018.07.046