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

Abstract

In this work, we characterize nor-β-lapachone-loaded (NβL-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 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-β-lapachone molecule and the surface of the microparticles. The NβL-loaded PLGA microcapsules exhibited a pronounced initial burst release. After the treatment with NβL-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.

Tumor-Specific Expansion of Oxidative Stress by Glutathione Depletion and Use of a Fenton Nanoagent for Enhanced Chemodynamic Therapy

“…The pure Lapa spectrum (a) exhibited a group of scattered low-intensity absorption peaks between 500 and 1740 cm –1 . The characteristic peaks of pure Lapa were seen at 1113, 1313, 1568, 1599, and 1635 cm –1 . In comparison, these spectra were also present in the spectrum of Fe 3 O 4 -HSA@Lapa NPs (e) and absent in unloaded nanoparticles (b–d).…”

“…The characteristic peaks of pure Lapa were seen at 1113, 1313, 1568, 1599, and 1635 cm −1 . 46 In comparison, these spectra were also present in the spectrum of Fe 3 O 4 -HSA@Lapa NPs (e) and absent in unloaded nanoparticles (b−d). The characteristic peaks at 1313 and 1113 cm −1 were caused by the C−O−C group of Lapa.…”

“…47 The peak at 1568 cm −1 could be attributed to the bending motion of the CH 3 groups in the Lapa molecule, while the absorption peak at 1599 cm −1 could be attributed to the bending of two CH bonds in the benzene region of Lapa. 46,47 The peak at 1635 cm −1 represented the combination of CH 3 shearing motions and CH benzene bending with minor C−C bond stretching. 46 FT-IR characterization further verified successful surface modification of Fe 3 O 4 NPs and successful preparation of Fe 3 O 4 -HSA@Lapa NPs.…”

“…46,47 The peak at 1635 cm −1 represented the combination of CH 3 shearing motions and CH benzene bending with minor C−C bond stretching. 46 FT-IR characterization further verified successful surface modification of Fe 3 O 4 NPs and successful preparation of Fe 3 O 4 -HSA@Lapa NPs. According to dynamic light scattering (DLS) results (Figure 2C), the average diameter of Fe 3 O 4 NPs was approximately 10 nm, consistent with TEM results.…”

Qualification of Non-Halogenated Organic Solvents Applied to Microsphere Manufacturing Process

“…However, it should be noted that the use of methylene chloride does not always bring high EE to many hydrophobic drugs. For example, when nor-β-lapachone was loaded into PLGA microspheres via a methylene chloride-based solvent evaporation process, its EE was only 19.4% [32].…”