Novel Heterotopic Colloids of Anionic Porphyrins Entangled in Cationic Amphiphilic Cyclodextrins: Spectroscopic Investigation and Intracellular Delivery

Abstract

The entanglement process between water-soluble 5,10,15,20-tetrakis(4-sulfonatophenyl)-21H,23H-porphine and the amphiphilic cyclodextrin (CD) heptakis(2-omega-amino-O-oligo(ethylene oxide)-6-hexylthio)-beta-CD and the occurrence of various species at different porphyrin:CD ratios were studied by a combination of UV/Vis absorption, fluorescence anisotropy, time-resolved fluorescence, resonance light scattering, and circular dichroism. The effect of the entanglement process on the mean vesicle diameter was investigated over a wide concentration range by quasielastic light-scattering techniques. The experimental results indicate that the presence of porphyrins in this colloidal system promotes some structural rearrangements, essentially driven by charge interaction, which are responsible for a sensitive change of vesicle dimensions. In the range of porphyrin:CD molar ratios between 1:10 and 1:50, the porphyrin is solubilized in monomeric form (tau(1)=11.5 ns) and photosensitizes the production of singlet oxygen ((1)O(2)). At the same molar ratio the ability of this amphiphilic cyclodextrin to transport porphyrins into tumor cells indicates specificity at the nuclear-compartment level. These findings may be of potential interest for the of development agents for photodynamic therapy of tumors.

Translational and Rotational Motions of Albumin Sensed by a Non-Covalent Associated Porphyrin Under Physiological and Acidic Conditions: A Fluorescence Correlation Spectroscopy and Time Resolved Anisotropy Study

“…Table 1. In the case of TSPP alone, emission decays show a biexponential behavior at both pHs with a prevalent long lifetime of 3.78 ns for the di-protonated species (whose contribution depends on emission wavelength) and 9.58 ns for the tetra-anionic one in good agreement with reported values [34][35][36]. The existence of a sub-nanosecond component had already been reported by others for the aqueous system [13] and attributed to the aggregation of this porphyrin, most probably smaller or less organized aggregates or even a mixture of H-and J-dimers [34], which in the present case, would be induced by the increased ionic strength of the buffered media.…”

Cancer, Photodynamic Therapy and Porphyrin-Type Derivatives

“…Moreover, CDs can reduce the toxicity of the drug molecules and of the grafted polymers and to bring additional benefits such as membrane absorption enhancement, molecular stabilization, and improvement of water solubility as well as the availability of drugs in biological systems (Peng et al 2017). Actually, the conjugation of PSs with these non-toxic molecules showed improvement on their amphiphilicity, biocompatibility and availability at the surface of cancer cell membranes (Mazzaglia et al 2003, Sortino et al 2006.…”

Synthesis of Sulfated Cyclodextrin Amphiphiles with Liposomal Encapsulation Properties

“…Such amphiphilic CDs have been prepared by grafting hydrocarbon chains on the hydroxyl groups of α-, β-, or γ-CD. For example, a Medusa-like CD was obtained by grafting hydrophobic groups onto all the primary hydroxyl groups of a β-CD [15]- [19]. Skirt-shaped CDs were obtained corresponding to esterification or alkylation of all the secondary hydroxyl groups [20] [21].…”