Properties of Polyethylene Glycol Supported Tetraarylporphyrin in Aqueous Solution and Its Interaction with Liposomal Membranes

Abstract

5,10,15,20-Tetrakis(4-hydroxyphenyl)porphyrin was functionalized by covalent attachment of poly(ethylene glycol) (PEG) chains of various molecular weights, 350, 2000, and 5000 Da. The properties of PEG-functionalized tetraarylporphyrins in aqueous solution and their interactions with liposomes have been studied. Electronic absorption spectroscopy, dynamic light scattering, atomic force microscopy, and fluorescence quenching were used to monitor aggregation of porphyrin chromophores and behavior of the attached PEG chains in the aqueous solution. The tendency for aggregation of porphyrin chromophores in aqueous solution and the efficiency of fluorescence quenching by KI decrease with increasing length of PEG chain linked to the porphyrin ring. The experimental results indicate that polymer clusters are present in aqueous solution of all pegylated porphyrins. The interactions between the pegylated porphyrins and phosphatidylcholine liposomes in the aqueous solution were studied using the fluorescence methods. The apparent binding constants of porphyrin chromophores to liposomes were determined. The degree of binding was found to be dependent on the molecular weight of the attached polymer.

Synthesis of a poly(ethylene glycol) galloyl sensitizer tip for an ’all‐in‐one' photodynamic device

“…TriPEG‐galloyl pheophorbide and triPEG‐chlorin (entries 2 and 4) led to a lipophilic deamplification by 1.9 log units compared to unsubstituted sensitizers, respectively (entries 1 and 3). Lower log P values of PEGylated compounds would be expected, where their curling onto the porphyrin ring inhibits aggregation due to π–π stacking forces . The reduced log P of the PEGylated pheophorbide versus native hydrophobic pheophorbide‐ a will make the former more accessible and less prone to aggregating, to potentially address the challenge in sterilization of surgical margins.…”

New Pegylated Unsymmetrical meso-Arylporphyrins as Potential Photosensitizers

“…It has been reported that PEG-containing porphyrins can be prepared by alkylation of the hydroxyl groups in the mesosubstituted porphyrins by the action of methoxypolyethylene tosylates or mesylates. [14] We used an alternative strategy for the synthesis of such compounds -mixed aldehyde monopyrrole condensation using benzaldehydes functionalized by polyethylene oxide residues. To optimize the obtaining of target A 3 B-and AB 3 -meso-arylporphyrins two strategies of pyrrole and substituted benzaldehydes condensation were examined: in a mixture of organic solvents [15,16] and in an aqueous micellar medium.…”

Modifications of Porphyrins and Hydroporphyrins for Their Solubilization in Aqueous Media

“…Under similar conditions, single PEG chains or PEG-dendrimers ( Scheme 41 ) [ 142 ] can also be introduced into asymmetric meso -hydroxyphenylporphyrins [ 143 , 144 ]. Vitalini and co-workers prepared PEGylated derivatives of 76 by alkylation of the phenolic oxygens with a chlorinated PEG [ 145 ].…”