Interactions between cationic surfactants and 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin tetrasodium salt as seen by electric conductometry and spectroscopic techniques

Supramolecular Self-Assembly of Porphyrin and Metallosurfactant as a Drug Nanocontainer Design

“…Aggregation behavior in the TSPP-LaSurf system is also confirmed by experiments on TSPP fluorescence. The emission spectrum of pure TSPP in an aqueous medium shows two bands: more intense band at 644 nm and less intense of aggregates at 704 nm (Figure 4a), which confirms the dominance of the monomeric form of TSPP [27,38]. The addition of the first portions of LaSurf up to equimolar ratio leads to an increase in fluorescence (Figure 4a), which is probably caused by the formation of monomeric complexes, but not aggregates based on them [35].…”

“…UV spectra of 0.0025 mM TSPP solution in the absence and in the presence of various amounts of LaSurf are shown in Figures 2 and 3. Considering the extensive literature data devoted to the study of the spectral properties of TSPP [27,38,43,53], it can be assumed that TSPP at a concentration of 0.0025 mM in an aqueous medium is in the form of a monomer, in which nitrogen atoms are not protonated, and sulfonate groups are dissociated to form four negatively charged groups. In the UV spectrum of pure TSPP, there is an intense Soret band at 413 nm (Figure 2a), as well as four distinguishable Q bands of comparatively lower intensity at 516 nm, 552 nm, 579 nm, and 634 nm (Figure 3a).…”

“…Thus, after full electrostatic compensation of TSPP charges at TSPP:LaSurf = 1:2 ratio, an increase in the LaSurf fraction leads to an increase in the contribution of the hydrophobic effect to the formation of mixed aggregates. Taking into account the literature data, it can be assumed that after reaching a two-fold excess of LaSurf in the mixed system, with an increase in the LaSurf fraction, micellar aggregates begin to form, in which TSPP molecules either fold into J-aggregates on the micelle surface [36,37], or together with LaSurf complex are solubilized inside individual micelles [30,38,63].…”

“…In addition, if the porphyrin molecule has a charge, then the macrocycle may not solubilize into micelles of ionic surfactants, but cover their surface due to electrostatic interaction [35][36][37]. Much less emphasis is placed on the premicellar supramolecular porphyrin-surfactant complexes formed at amphiphile concentration that is considerably less than its critical micelle concentration [27,38,39]. The TSPP molecule forms complexes with cationic amphiphiles in a ratio of 1:4, in which four negatively charged groups of one porphyrin molecule are completely neutralized by four surfactant molecules.…”

A Review on (Hydro)Porphyrin-Loaded Polymer Micelles: Interesting and Valuable Platforms for Enhanced Cancer Nanotheranostics

“…Most of the porphyrins designed as therapeutic agents are hydrophobic, with poor solubility in water. Aggregation in aqueous systems is a common problem [ 26 , 27 ] which has been the driving force behind the search of efficient delivery systems [ 28 , 29 , 30 ], including nanoparticles.…”