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In water–DMF at DMF content less than 2.6 mol dm−3, deuteroporphyrin IX dimethyl ester forms both H- and J-aggregates. The J-aggregates are detected as a single type of associated species after binding of the porphyrin with BSA on the surface of the protein IB subdomain.

Protoporphyrin upon its binding with serum albumin changes its secondary structure due to the conversion of part of α helices into β-folding. This process results in the association of albumin globules in vitro.

Glycosized porphyrins are promising compounds for using in PDT, since they combine the ability to act as a photosensitizer, and their saccharide residues provide an increased tumorotropicity of this compound in the affected cells. In this work, the modified 5,10,15,20-tetrakis [4-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl) phenyl] porphine (HOGalPor) synthesis procedure providing an increased yield of the desired product is described. The affinity of natural biopolymers with reference to synthesized porphyrin has been studied. It was found that synthesized porphyrin is associated in aqueous media. There were proposed some mixed solvents and water-solvent concentration ratios were established to ensure the monomerization of porphyrin and the preservation of the native conformation of biopolymers (BSA and DNA). The affinity constants of BSA and DNA were determined with reference to the synthesized porphyrin, as well as localization of porphyrin in biopolymers was established. As part of the protein complex, porphyrin fluoresces very intensively, and this feature makes it possible to use BSA as a transport system for HOGalPor, and HOGalPor itself can act as a fluorescent marker. The interaction of HOGalPor with the intercalation complex of DNA-EtBr leads to the destruction of the latter, while porphyrin does not intercalate in DNA, but forms external complexes with a change in the zeta potential of the surface.

The problem of treating viral infections is extremely relevant due to both the emergence of new viral diseases and to the low effectiveness of existing approaches to the treatment of known viral infections. This review focuses on the application of porphyrin, chlorin, and phthalocyanine series for combating viral infections by chemical and photochemical inactivation methods. The purpose of this review paper is to summarize the main approaches developed to date in the chemical and photodynamic inactivation of human and animal viruses using porphyrins and their analogues and to analyze and discuss the information on viral targets and antiviral activity of porphyrins, chlorins, of their conjugates with organic/inorganic compounds obtained in the last 10–15 years in order to identify the most promising areas.

The influence of irradiation on protein- porphyrin complexes at various spectral ranges was studied. Limited applicability of evaluating protein damage degree in terms of fluorescence quenching of the tryptophan protein residues was shown. Depending on the conditions of photoirradiation and the way of porphyrins interaction with bovine serum albumin (BSA), photoirradiation of the porphyrin-protein complexes may result in proteolysis or photolinking inside the protein globule, and in some cases, in destruction of the complex itself. P1 5-(4′-N-tertbutyloxycarbonylglicinaminophenyl)-10,15,20-triphenylporphine, unlike 5,10,15,20-tetraphenylporphin (TPP), has fixed localization in the protein due to “anchor” group providing the stability of the photoinduced transformations of a protein globule. For all porphyrin-protein systems studied, irradiation by light at the Soret band range for P1-protein systems leads to proteolysis of BSA globule, while the irradiation by light with the wavelength more than 500 nm, does not result in total protein damage, but causes oxidation of susceptible amino acid residues. The measurement of the hydrodynamic radii of a protein globule before and after irradiation provided objective information on the proceeding photoinduced processes (proteolysis and crosslinking) which can be used for predicting the mechanism of the cell damage (necrosis, autophagy, apoptosis).

This study was focused on obtaining polymer complex of 5-(4′-N-tert-butyloxycarbonylglicinaminophenyl)-10,15,20-triphenylporphine and 5-(4′-amonophenyl)-10,15,20-triphenylporphine with chitosan. The polymer complexes were characterized spectrally and calorimetrically. The existence of a substituent capable of forming hydrogenic complexes with proteins and other biopolymers in porphyrins provides an effective immobilization of a photosensitizer. Binding with porphyrins was found to result in twisting the chitosan globule and encapsulation of porphyrins. Coating of polymer complex with bovine serum albumin promotes neutralization of zeta potential and formation of 180-nm capsules. As the result of the study, a new universal strategy of water insoluble preparation encapsulation in biopolymers for targeted delivery of drugs and their further release was suggested.

The interaction of water-soluble porphyrins with the bovine serum albumin in borate buffer at pH 8.6 has been studied. The localization of porphyrins in the protein globule has been determined. It was established that the native conformation of albumin upon binding with the porphyrins is preserved, however, the anionic porphyrins are exhibit wedging effect on the albumin domains. The binding constants were obtained from fluorescence spectroscopy data.

New copolymers of acrylamide with zinc 5,10,15,20-tetrakis-(4-allyloxyphenyl)porphyrinate were synthesized and tested as cysteine and histidine sensors.

In this paper, the results of a spectral and thermochemical study of the DNA polyplex formation with chitosan and the effect of ethidium bromide polyplexes, sodium dodecyl sulfate, n-octyltrimethyl ammonium bromide, poly(4-styrenesulfonic acid), and heparin on the stability of the complexes are considered. It has been established that chitosan forms thermodynamically stable complexes with ethidium bromide (EtBr), in which there exists one monomer unit of chitosan for two ethidium bromide ones. The interaction of ethidium bromide with chitosan leads to a charge exchange of the polymer surface. The impact of chitosan on the intercalated DNA-EtBr complex conditions a release of EtBr with a polyplex formation. The process of polyplex formation in the presence of ethidium bromide proceeds endothermically, and in its absence the reaction is exothermic. The polyplex particles formed from DNA after release of EtBr are larger and have a smaller charge, as compared to the polyplex particles obtained without ethidium bromide. It has been found that anionic compounds cause the degradation of polyplexes, and it can prove to be a significant obstacle for using chitosan polyplexes in transfection, since in the presence of heparin in the bloodstream, the complexes will break down before reaching the target.

Spectral, hydrodynamic and thermochemical studies have been demonstrated that tetraalkoxy substituted zinc(II)phthalocyanines form stable complexes with defatted and nondefatted bovine serum albumin. The phthalocyanines interact with BSA through heteroatoms of their peripheral substitutes. It was found that ZnPc(4-NH-CO-C6H4-OC3H7)4 is located in the protein subdomains IB and IIA whereas ZnPc(4-NHCO-C6H4-OC6H13)4 and ZnPc(4-NH-CO-C6H4-OC8H17)4 are immobilized on surface of the protein globule at a distance of not greater than 10 nm from the tryptophan residues in the positions 135 and 214 of the protein polypeptide chain. Zinc(II)phthalocyanines (ZnPc(4-NH-CO-C6H4-OC6H13)4 and ZnPc(4-NH-CO-C6H4-OC8H17)4) increase thermal stability of BSA.

Molecular complex formation of zinc(II)tetraphenylporphyrin with the ligands—diamino compounds in toluene was studied using calorimetric and spectroscopy titration. The structure of the complexes has been confirmed using 1H NMR and fluorescence spectroscopy. Nature of the interaction between the ligand and the solvent was established using TGA of solvates.

The possibility of creating a pH-controllable protein container for the delivery of hydrophobic porphyrins as photosensitizers in cancer cells has been demonstrated.

The interaction of tetracationic porphyrins with DNA was studied using UV-Vis absorption, fluorescence spectroscopy and viscometry, and the particle sizes were determined. Аs cationic porphyrins, two isomer porphyrins, 3,3',3″,3‴-(5,10,15,20-Porphyrintetrayl)tetrakis(1-methylpyridinium) (TMPyP3) and 4,4',4″,4‴-(5,10,15,20-Porphyrintetrayl)tetrakis(1-methylpyridinium) (TMPyP4), were studied. They differ in the position of NCH3+ group in phenyl ring of the porphyrins and hence, in degree of freedom of rotation of the phenyl rings about the central macrocycle. It was found that intercalated complexes are formed at DNA/porphyrin molar ratios (R) of 2.2 and 3.9 for TMPyP3 и TMPyP4, respectively. Decreasing R up to 0.4 and 0.8 for TMPyP3 и TMPyP4, respectively, leads mainly to formation of outside complexes due to π-π stacking between the porphyrin chromophores interacting electrostatically with phosphate framework of DNA. Each type of the obtained complexes was characterized using Scatchard approach. It was ascertained that the affinity of TMPyP4 to DNA is stronger than TMPyP3, meanwhile the wedge effect of the latter is higher. The differences between the porphyrin isomers become more evident at irradiation of their complexes with DNA. It was established that irradiation of the intercalated complexes results in DNA fragmentation. In the case of TMPyP4, DNA fragments of different size are formed. The irradiation of the outside DNA/porphyrin complexes leads to cleavage of DNA (TMPyP3 and TMPyP4) and partial destruction of the complex due to photolysis of the porphyrin (TMPyP3).