Hematoporphyrin dihydrochloride (Hematoporphyrin IX dihydrochloride)

Highly efficient and biocompatible nanoparticle-based photosensitizer for treatment of acne vulgaris

Aim: Nanoparticle-based photosensitizers containing silver core and mesoporous silica shell with hematoporphyrin IX embedded were developed to treat vulgaris photodynamically. Materials & methods: The hybrid photosensitizers were dispersed in 30% polyethylene glycol (PEG-200) solution and used for the photodynamic treatment of Staphylococcus epidermidis and Propionibacterium acnes under the illumination of a portable LED (?410 nm). Results: After a 5 min illumination by the LED, the hybrid photosensitizers of 50 μg/ml displayed killing efficacy of approximately 5-log for S. epidermidis and approximately 4-log for P. acnes. Results indicated that hybrid photosensitizers in PEG-200 matrix perform better than in deionized (DI) water (?1-log increase in killing efficacy). Conclusion: Under short illumination of a portable LED, hybrid photosensitizers demonstrated immense potential for treatment of acne vulgaris without involving antibiotics.

DNA-drug interaction measurements using surface plasmon resonance

The interactions of the drugs 2,7-bis[(diethylamino)-ethoxy]-fluoren-9-one dihydrochloride (Tilorone), 2,7-bis[(dipropylamino)-acetamido]-fluoren-9-one dihydrochloride (FA-2), 2'-(4-hydroxyphenyl)-5-(4-methyl-1-piperazinyl)-2,5'-bi-1H-benzimidazole trihydrochloride (Hoechst 33258), and hematoporphyrin IX derivative (HPD) with synthetic self-complementary DNA (36-b.p.; 5'-biotin-spacer-[d(CGCTATATAGCG)]3-3') were studied by SPR (Surface Plasmon Resonance). Monolayers of biotinylated DNA were immobilized on a streptavidin-dextran-gold triple-layer. Small portions of the drugs (approximately 30 pmol/ml) were injected in continuous flow. The mass corresponded to the amount of the bound molecules. Injections of 50 mM sodium hydroxide pulses separated the DNA double strands, releasing the effector molecules. Subsequent treatments with the effectors gave reproducible results. The maximum interaction between drug and DNA was observed in the case of Tilorone. 41 molecules could bind to the 36-b.p. DNA duplex. To investigate the microscopic behavior in condensed nucleic acid phases, SFM (Scanning Force Microscopy)-imaging and polarizing microscopic observations of DNA-effector complexes were carried out. Supplementary UV-absorption thermal denaturation curves of DNA with the above-mentioned effectors in dilute solutions were measured. As an additional aid to understand the geometries of DNA-drug interactions, computer simulations were performed and compared with the experimental data.

Separation of overlapping spectra from evolving systems using factor analysis. 4. Fluorescence spectra of hematoporphyrin IX

Fluorescence spectra of hematoporphyrin IX (Hp) in water and in aqueous SDS solutions are obtained in the pH range 0.1 to 13 to determine the ionisation state of the molecule as a function of pH. In water, the spectra are complicated by aggregation which is quite severe near pH 4. In aqueous SDS, the aggregation is much less violent. Factor analysis (FA) is used to identify five species in the fluorescence spectra in each series of solutions. The distribution curve of these species as a function of pH is also obtained. By comparing the spectra and the distribution curve of Hp with those of HPPEEA, an ethanolamide derivative of Hp that does not contain the carboxylic groups (Part 3), the species are identified. For Hp in water we have obtained the following species: the dication in two allotropic forms in the pH range 0 to 5; the monocation (with the charge on an imino nitrogen) in the pH range 2 to 7; and the free base in the pH range 3.5 to 13. The monocation observed by the second derivative technique revealed three subspecies. For Hp in aqueous SDS we have obtained the following species; one dication in the pH range 0 to near 4; one monocation (with the charge on an imino nitrogen) in the pH range 0.5 to 9; three free bases (with no charge on the imino nitrogen) in the pH range 4 to 13. Of the latter, one species is the neutral molecule, another is a dianion (with the charges on the carboxylic side chains), and the third one appearing at pH higher than 10 is an allotropic form of the dianion.

Separation of overlapping spectra from evolving systems using factor analysis. 3. Fluorescence spectra of hematoporphyrin IX di-n-propylether diethanolamide

Fluorescence spectroscopy of hematoporphyrin IX di-n-propylether diethanolamide (HPPEEA) in aqueous solutions, with and without SDS, was obtained in the pH range from 0.1 to 13. At pH greater than 3, HPPEEA in water solutions gives spectra complicated by aggregation whereas in aqueous SDS solutions, the aggregation is greatly reduced. Factor analysis is used to separate the spectra of the individual species from the experimental spectra. Five and four species are identified in pure water and in aqueous SDS solutions, respectively. The predominant species are: two free bases at pH higher than 6; one monocation at pH near 4; and two or one dications at pH lower than 2.5. The intensity signatures are related to the ionic distribution and to the aggregation situation of HPPEEA at different pH.

Microemulsion and micellar electrokinetic chromatography of Hematoporphyrin D: a starting material of hematoporphyrin derivative

An investigation of the basic factors which govern the microemulsion electrokinetic chromatography (MEEKC) and micellar electrokinetic chromatography (MEKC) separation of Hematoporphyrin D and its base hydrolysis product, hematoporphyrin derivative (HpD), was performed. These model compounds contain a complex mixture of porphyrin monomers, dimers and/or oligomers, and were utilized to gain insights into the MEEKC/micellar electrokinetic chromatography (MEKC) separation of samples containing highly lipophilic substances. For example, the organic modifier/cosurfactant (1-butanol) and/or oil phase (e.g., 1-octanol in comparison to ethyl acetate) were found to have an apparent influence on the separation selectivity of Hematoporphyrin D, the extent of which was dependent on the chemical nature of the surfactant employed (e.g., sodium dodecyl sulfate vs. sodium cholate). An interesting and important finding was that the presence of an organic modifier (methanol or acetonitrile at a concentration of 20% or higher) in the sample matrix as well as in the run buffer was essential for the optimal MEEKC or MEKC separation of a number of porphyrin monomers (including hematoporphyrin IX and its acetates, most likely hydroxyacetate, diacetate, and vinyl acetate, as well as its dehydration products, hydroxyethylvinyldeuteroporphyrin and protoporphyrin) contained in Hematoporphyrin D. On the other hand, the use of these optimized conditions for the MEEKC or MEKC separation of various oligomeric porphyrin species in HpD were unsatisfactory. As HpD is a well-known and effective photosensitizing agent in photodynamic therapy (a new approach for cancer treatment), the improved separation and characterization of various monomeric and oligomeric porphyrin species in HpD and its starting material, such as Hematoporphyrin D, is a challenging and important task.