ABSTRACT
Thymoquinone (TQ) was complexed with beta-cyclodextrin (CD) to form nanosized aggregates. Various TQ:CD ratios were tested and it was found that the ratio of (1:0.25) TQ:CD formed distinguishable nanoparticles with minimum toxicity towards normal cells. These nanoparticles had an average size of 445 +/- 100 nm with a charge 21.8 mV using Zeta-sizer. Particle size measurement using scanning electron microscopy (SEM) showed an average size of 400 nm and it also revealed the presence of smaller structures, with an average size of 50 nm. The in vitro antiproliferative activity on MCF7 cells was determined using MTT assay and an IC50 of 4.70 +/- 0.60 microM for TQ-CD nanoparticles in comparison to 24.09 +/- 2.35 microM of free TQ solution after 72 h of incubation. Simultaneously, TQ-CD nanoparticles showed lesser toxicity than TQ solution using human periodontal fibroblasts as a model for normal cells. It could be concluded from the results that TQ loaded cyclodextrin nanoparticles might serve as a potential nanocarrier to improve TQ solubility as well as its antiproliferative activity with little toxicity to normal tissues.
Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Benzoquinones/chemistry , Benzoquinones/pharmacology , Cell Proliferation/drug effects , Nanoparticles/chemistry , beta-Cyclodextrins/chemistry , beta-Cyclodextrins/pharmacology , Calorimetry, Differential Scanning , Cell Line, Tumor , Cell Survival/drug effects , Electrochemistry , Humans , Microscopy, Electron, Scanning , Particle Size , Spectroscopy, Fourier Transform InfraredABSTRACT
The inhalation route is of increasing interest for both local and systemic drug delivery, including macromolecular biopharmaceuticals, such as peptides, proteins, and gene therapeutics. In addition to appropriate aerosolization for deposition in relevant areas of the respiratory tract, therapeutic molecules may require an advanced carrier system for safe and efficient delivery to their target. Two approaches to obtain novel carrier systems for pulmonary drug delivery are large porous microparticles with a low aerodynamic diameter and lectin-functionalized liposomes. Epithelial cells of alveolar or bronchial origin, obtained either from patient material or from established cell lines, can be grown on permeable filter supports, resulting in polarized monolayers with functional intercellular junctions. With such in vitro models, transport of drugs into pulmonary epithelial cells and/or across the air-blood barrier, as well as the effect and efficacy of novel drug carrier systems can be systematically studied.
Subject(s)
Drug Carriers , Respiratory Mucosa/metabolism , Absorption , Administration, Inhalation , Biological Transport , Blood-Air Barrier , Cells, Cultured , Drug Delivery Systems , Epithelial Cells/metabolism , Humans , In Vitro Techniques , Lectins , Liposomes , Microscopy, Electron, Scanning , Microspheres , Nebulizers and Vaporizers , Particle Size , Pulmonary Alveoli/metabolismABSTRACT
In this study the interaction of lectin-functionalized liposomes with two different alveolar epithelial cell culture models was evaluated. Plant lectins were coupled to liposomes exploiting the avidin/biotin technology. In contrast to lectin-free liposomes, lectin functionalized liposomes specifically bound to A549 cells, a tumor-derived cell line. Using this cell line, temperature-dependent binding assays as well as confocal laser scanning microscopy (CLSM) revealed that the lectin liposomes were only bound but not taken up by these cells. In contrast to these findings, confocal images of human alveolar epithelial cells in primary culture incubated together with lectin liposomes indicated binding as well as cellular uptake. Fluorescein-isothiocyanate (FITC)-labeled dextrans (Mw 40,000 Da), encapsulated in lectin-functionalized liposomes and incubated with monolayers of primary cultured human alveolar epithelial cells appeared to be localized intracellularly by CLSM. This suggests that lectin-mediated bioadhesion and uptake of liposomal carriers may provide a useful technology for improved delivery of hydrophilic macromolecules to the alveolar epithelium.
Subject(s)
Lectins/metabolism , Liposomes/pharmacology , Pulmonary Alveoli/metabolism , Tumor Cells, Cultured/metabolism , Cells, Cultured , Drug Delivery Systems , Fluorescein-5-isothiocyanate , Humans , Lectins/pharmacology , Pulmonary Alveoli/drug effects , Tumor Cells, Cultured/drug effectsABSTRACT
The generation of respirable aerosols of a functionalized colloidal carrier has been investigated in this study. Lectin-functionalized liposomes, which proved to show improved cell association (using A549 cell line and primary human alveolar cells) even in the presence of a commercial lung surfactant preparation, have been developed. The stability of non-functionalized liposomes during nebulization using a jet nebulizer (Pari II provocation nebulizer, operated using an air flow of 30 l/min) was firstly investigated, and the experimental and formulation conditions were optimized and applied for the preparation of lectin-functionalized liposomes. The incorporation of cholesterol enhanced the stability of the liposomes during nebulization (from 15-20% leakage of a hydrophilic marker to 8% upon cholesterol incorporation) and upon incubation with lung surfactant preparation. Nebulization of the functionalized liposomes did not significantly influence their physical stability. Their enhanced cell binding capability (compared to non-functionalized liposomes) was also maintained. A drop in cell association compared to fresh functionalized liposomes was detected after nebulization, nevertheless, the binding was still significantly higher than that of the non-functionalized liposomes. The deposition of the liposomal preparation in lung periphery, proved by the deposition of the liposomal preparation on the lower stages of an ASTRA type cascade impinger and a mean median aerodynamic diameter (MMAD) of 2.85 microm, makes it a potential candidate as a macromolecule-drug carrier for local and/or systemic administration.
