RESUMEN
LPSF/AC04 (5Z)-[5-acridin-9-ylmethylene-3-(4-methyl-benzyl)-thiazolidine-2,4-dione] is an acridine-based derivative, part of a series of new anticancer agents synthesized for the purpose of developing more effective and less toxic anticancer drugs. However, the use of LPSF/AC04 is limited due to its low solubility in aqueous solutions. To overcome this problem, we investigated the interaction of LPSF/AC04 with hydroxypropyl-ß-cyclodextrin (HP-ß-CyD) and hydroxypropyl-γ-cyclodextrin (HP-γ-CyD) in inclusion complexes and determine which of the complexes formed presents the most significant interactions. In this paper, we report the physical characterization of the LPSF/AC04-HP-CyD inclusion complexes by thermogravimetric analysis, differential scanning calorimetry, infrared spectroscopy absorption, Raman spectroscopy, (1)HNMR, scanning electron microscopy, and by molecular modeling approaches. In addition, we verified that HP-ß-CyD complexation enhances the aqueous solubility of LPSF/AC04, and a significant increase in the antiproliferative activity of LPSF/AC04 against cell lines can be achieved by the encapsulation into liposomes. These findings showed that the nanoencapsulation of LPSF/AC04 and LPSF/AC04-HP-CyD inclusion complexes in liposomes leads to improved drug penetration into the cells and, as a result, an enhancement of cytotoxic activity. Further in vivo studies comparing free and encapsulated LPSF/AC04 will be undertaken to support this investigation.
Asunto(s)
Acridinas/química , Acridinas/farmacología , Antineoplásicos/química , Antineoplásicos/farmacología , Liposomas/química , Tiazolidinedionas/química , Tiazolidinedionas/farmacología , beta-Ciclodextrinas/química , gamma-Ciclodextrinas/química , 2-Hidroxipropil-beta-Ciclodextrina , Absorción , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Estabilidad de Medicamentos , Excipientes/química , Humanos , Solubilidad , Agua/químicaRESUMEN
The aim of this study was to encapsulate lapachone (ß-lap) or inclusion complex (ß-lap:HPß-CD) in liposomes and to evaluate their physicochemical characteristics. In addition, the investigation of the main aspects of the interaction between ß-lap and 2-hydroxypropyl-ß-cyclodextrin (HPß-CD), using both experimental and molecular modeling approaches was discussed. Furthermore, the in vitro drug release kinetics was evaluated. First, a phase solubility study of ß-lap in HPß-CD was performed and the ß-lap:HPß-CD was prepared by the freeze-drying technique. A 302-fold increase of solubility was achieved for ß-lap in HPß-CD solution with a constant of association K(1:1) of 961 M(-1) and a complexation efficiency of ß-lap of 0.1538. (1)H NMR, TG, DSC, IR, Raman and SEM indicated a change in the molecular environment of ß-lap in the inclusion complex. Molecular modeling confirms these results suggesting that ß-lap was included in the cavity of HPß-CD, with an intermolecular interaction energy of -23.67 kJ mol(-1). ß-lap:HPß-CD and ß-lap-loaded liposomes presented encapsulation efficiencies of 93% and 97%, respectively. The kinetic rate constants of 183.95±1.82 µg/h and 216.25±2.34 µg/h were calculated for ß-lap and ß-lap:HPß-CD-loaded liposomes, respectively. In conclusion, molecular modeling elucidates the formation of the inclusion complex, stabilized through hydrogen bonds, and the encapsulation of ß-lap and ß-lap:HPß-CD into liposomes could provide an alternative means leading eventually to its use in cancer research.
Asunto(s)
Adyuvantes Farmacéuticos/química , Modelos Moleculares , Naftoquinonas/administración & dosificación , Naftoquinonas/química , beta-Ciclodextrinas/química , 2-Hidroxipropil-beta-Ciclodextrina , Composición de Medicamentos , Liofilización , Liposomas , Microscopía Electrónica de Rastreo , Estructura Molecular , Transición de Fase , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría Raman , Propiedades de SuperficieRESUMEN
The cellular uptake and antimycobacterial activity of usnic acid (UA) and usnic acid-loaded liposomes (UA-LIPOs) were assessed on J774 macrophages. The minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) of UA and UA-LIPO against Mycobacterium tuberculosis were determined. Concentrations required to inhibit 50% of cell proliferation (IC(50)) were 22.5 (+/-0.60) and 12.5 (+/-0.26) microg/ml, for UA and UA-LIPO, respectively. The MICs of UA and UA-LIPO were 6.5 and 5.8 microg/mL, respectively. The MBC of UA-LIPO was twice as low (16 microg/mL) as that of UA (32 microg/mL). An improvement in the intracellular uptake of UA-LIPO was found (21.6 x 10(4) +/- 28.3 x 10(2) c.p.s), in comparison with UA (9.5 x 10(4) +/- 11.4 x 10(2) c.p.s). In addition, UA-LIPO remains much longer inside macrophages (30 hours). All data obtained from the encapsulation of usnic acid into liposomes as a drug delivery system (DDS) indicate a strong interaction between UA-liposomes and J774 macrophages, thereby facilitating UA penetration into cells. Considering such a process as ruling the Mycobacterium-transfection by magrophages, we could state that associating UA with this DDS leads to an improvement in its antimycobacterial activity.