Encapsulation of nor-ß-lapachone into poly(d,l)-lactide-co-glycolide (PLGA) microcapsules: full characterization, computational details and cytotoxic activity against human cancer cell lines.

In this work, we characterize nor-ß-lapachone-loaded (NßL-loaded) microcapsules prepared using an emulsification/solvent extraction technique. Features such as surface morphology, particle size distribution, zeta potential, optical absorption, Raman and Fourier transform infrared spectra, thermal analysis data, drug encapsulation efficiency, drug release kinetics and in vitro cytotoxicity were studied. Spherical microcapsules with a size of 1.03 ± 0.46 µm were produced with an encapsulation efficiency of approximately 19%. Quantum DFT calculations were also performed to estimate typical interaction energies between a single nor-ß-lapachone molecule and the surface of the microparticles. The NßL-loaded PLGA microcapsules exhibited a pronounced initial burst release. After the in vitro treatment with NßL-loaded microcapsules, a clear phagocytosis of the spheres was observed in a few minutes. The cytotoxic activity against a set of cancer cell lines was investigated.

Controlled Release of Nor-ß-lapachone by PLGA Microparticles: A Strategy for Improving Cytotoxicity against Prostate Cancer Cells.

Prostate cancer is one of the most common malignant tumors in males and it has become a major worldwide public health problem. This study characterizes the encapsulation of Nor-ß-lapachone (NßL) in poly(d,l-lactide-co-glycolide) (PLGA) microcapsules and evaluates the cytotoxicity of the resulting drug-loaded system against metastatic prostate cancer cells. The microcapsules presented appropriate morphological features and the presence of drug molecules in the microcapsules was confirmed by different methods. Spherical microcapsules with a size range of 1.03 ± 0.46 µm were produced with an encapsulation efficiency of approximately 19%. Classical molecular dynamics calculations provided an estimate of the typical adsorption energies of NßL on PLGA. Finally, the cytotoxic activity of NßL against PC3M human prostate cancer cells was demonstrated to be significantly enhanced when delivered by PLGA microcapsules in comparison with the free drug.

Optical absorption of the antitrypanocidal drug benznidazole in water.

UV-vis optical absorption spectra of the antitrypanocidal drug benznidazole solvated in water were measured for various concentrations. The spectra show a prominent peak around 3.80 eV, while deconvolution of the UV-vis optical absorption spectra revealed six bands centered at 3.60, 3.83, 4.15, 4.99, 5.60, and 5.76 eV. Benznidazole electronic transitions were obtained after density functional theory (DFT) calculations within the polarized continuum (PCM) model for water solvation. Molecular geometry optimizations were carried out, and the measured absorption peaks were related to specific molecular orbital transitions obtained within the time dependent DFT (TD-DFT) with excellent agreement between theory and experiment.