The solution spectroscopy of drugs and the drug-nucleic acid interactions

Porumb, Horea

doi:10.1016/0079-6107(79)90017-8

Cited by 90 publications

(26 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The stoichiometry of the AO-ssRNA interactions has been investigated before (one-to-one ratio), but without recognizing that the final product is insoluble (16,30,33). Since during the precipitation, especially under conditions of A 0 excess, an occlusion of the free A 0 into the forming precipitate could take place, investigations were carried out to analyze the D/P ratio in these products.…”

Section: Resultsmentioning

confidence: 99%

Luminescence of the solid complexes of acridine orange with RNA

1982

View full text Add to dashboard Cite

The products of interaction between acridine orange (AO) and natural RNA, or the synthetic RNA homopolymers are precipitates insoluble over a wide range of ionic strength. These complexes have a composition of 1 AO molecule per 1 phosphate. The reaction is highly cooperative and the complex exhibits metachromatic luminescence. Significant differences in the luminescence spectra, related to base composition of RNA, characterize the insoluble complexes. This observation suggests that dye-base interactions take place in the AO-RNA complexes. During titration of poly(rA) with AO and simultaneous measurement of the luminescence and light scatter a two-step formation of the particles could be detected. The cooperative binding of the ligand at D/P less than 0.6 coincides with formation of small particles (molecular aggregates or micelles) and is followed at D/P greater than 0.6 by a cooperative agglomeration; the product of this agglomeration is particles of the size 0.35 micrometer and larger. Evidence is presented that suggests that the long wave length luminescence (approximately 650 nm) is a consequence of the solute-solid state transition of the AO-RNA interaction product rather than the classic dye-dye interactions previously visualized in the stacking model. Since these novel observations cannot be fully explained by the previously postulated molecular mechanisms of AO binding, an alternative model is advanced. Its implications in quantitative cytochemistry of nucleic acid as applied to flow cytometry are discussed.

show abstract

Section: Resultsmentioning

confidence: 99%

Luminescence of the solid complexes of acridine orange with RNA

1982

View full text Add to dashboard Cite

show abstract

“…It has been reported (Agrawal et al, 2009;Anand et al, 2012;Fulop et al, 2013;Hayakawa et al, 1991;Li et al, 1998;Porumb, 1978;Rizzo et al, 1989) that Dox tends to self-assemble in aqueous solutions forming dimers or higher order oligomers. The extent of agglomeration is highly sensitive to concentration of drug macromolecules, acidity of solution, and presence of additives (Anand et al, 2012;Hayakawa et al, 1991;Porumb, 1978). Self-assembling of Dox molecules leads to the changes in the relative intensities of absorption peaks in the visible region of spectra ( Figure 9).…”

Section: Isotherms Of Doxorubicin Adsorptionmentioning

confidence: 99%

“…Phosphate buffer medium may contribute to the adsorption process, as self-association of Dox is facilitated at ionic strength increasing (Hayakawa et al, 1991). Perhaps, phosphate ions promote stacking of the chromophores due to the screening of the positively charged Dox molecules or formation of intermolecular bonds (Porumb, 1978). Taking into consideration the geometry of pore structure of MCM-41, the formation of Dox polylayers mainly on the external surface of silica particles is quite probable (Figure 10).…”

Section: Isotherms Of Doxorubicin Adsorptionmentioning

confidence: 99%

Adsorption of antitumor antibiotic doxorubicin on MCM-41-type silica surface

Roik

Belyakova

Dziazko

2016

Adsorption Science & Technology

View full text Add to dashboard Cite

The aim of this study was to evaluate the adsorption behavior of doxorubicin on MCM-41 silica, which was synthesized by templated sol-gel method, as a function of contact time, pH of solution, and drug equilibrium concentration. Experimental kinetic curves of adsorption were compared with theoretical models of Lagergren and Ho-McKay for pseudo-first-and pseudo-second-order processes. Equilibrium adsorption of doxorubicin was analyzed by Langmuir, Freundlich, RedlichPeterson, and Brunauer-Emmet-Teller isotherm models. These results can be the basis for direct modification of MCM-41-type silicas sorption activity to drugs.

show abstract

“…The visible absorption spectrum of encapsulated DOX showed only slight differences from free DOX in aqueous solution, as illustrated in Figure 4.a; however, the presence of a red-shift in the absorption peak is a sign of increased local concentrations and also of DOX-DOX interactions, due to π-π stacking [29, 30]. More clear evidence came from the fluorescence spectrum (Figure 4.b), where a remarkable decrease in the fluorescence intensity was observed for the encapsulated drugs compared to equivalent free drug concentrations.…”

Section: Resultsmentioning

confidence: 99%

Physicochemical aspects of doxorubicin-loaded pH-sensitive polymeric micelle formulations from a mixture of poly(l-histidine)-b-poly(l-lactide)-b-poly(ethylene glycol)

Yin

Bae

2009

European Journal of Pharmaceutics and Biopharmaceutics

View full text Add to dashboard Cite

In this study, doxorubicin (DOX) was physically incorporated into pH sensitive micelles made from a mixture of poly(L--Histidine)-b-poly(ethylene glycol)/ poly(L--Lactide)-b-poly(ethylene glycol) (75/25, wt.%). The DOX-loaded mixed micelles were formulated using dialysis methods and optimal DOX incorporation was achieved at a drug/polymer feed ratio of 0.2 (wt./wt.) when proper amount of aqueous phase (0.2, v./v.) was added into the common solvent (DMSO) solution, followed by dialysis at 4°C. Based on the results obtained from dynamic light scattering, UV-Vis absorption, and fluorescence experiments, it was demonstrated that the encapsulated drugs were mainly located inside the hydrophobic micelle cores, well protected and inaccessible to exterior molecules. Under in vitro conditions, although the microstructure of the micelles was altered below pH 8.0 by the encapsulated drugs, the drug-loaded micelles still exhibited desirable ability to control the drug release in response to tumor extracellular pH.

show abstract

The solution spectroscopy of drugs and the drug-nucleic acid interactions

Cited by 90 publications

References 61 publications

Luminescence of the solid complexes of acridine orange with RNA

Luminescence of the solid complexes of acridine orange with RNA

Adsorption of antitumor antibiotic doxorubicin on MCM-41-type silica surface

Physicochemical aspects of doxorubicin-loaded pH-sensitive polymeric micelle formulations from a mixture of poly(l-histidine)-b-poly(l-lactide)-b-poly(ethylene glycol)

Contact Info

Product

Resources

About