ABSTRACT
Background and aims: Hydrophobic substances are mainly encapsulated into polymer nanocarriers in order to improve their solubility, enable their administration, at the same time to empower targeted tissue or cell specific delivery of the drug using the encapsulating vehicle as targeting and controlled release platform. 7-Ethyl-10-hydroxycamptothecin (SN-38) is an active metabolite of Irinotecan, showing 100-fold to 1000-fold higher effect than Irinotecan, but its clinical use is limited because of its extreme hydrophobicity, as it is practically insoluble in most physiologically compatible and pharmaceutically acceptable solvents. Method: In order to fully exploit the potential of the nanoprecipitation as a method for preparation of Poly(DL-lactide-co-caprolactone)-poly(ethylene oxide) - poly(propylene oxide) - poly(ethylene oxide) (P(DL)LCL/PEO-PPO-PEO) nanoparticles and evaluate the influence of the polymer P(DL)LCL, stabilizing agent PEO-PPO-PEO copolymer (Lutrol F127) and the drug concentration (SN-38) upon drug entrapment efficiency, size and drug content, a D-optimal experimental design for response surface using Design Expert Version 9.0.4.1. software investigation was created and statistically analyzed. Results: We have observed that at higher SN-38 concentration during the preparation procedure (nanoprecipitation, solvent diffusion method), and due to its extremely low water solubility, the drug will start to precipitate as unprotected crystals at a faster pace compared to polymer aggregation, leading to extremely low encapsulation efficacy and waste of the active compound. The most desirable combination of factor settings are SN-38 = 0.5 mg, Polymer = 5 mg and F127 = 4%. Conclusion: This investigation utilizes the design of experiment approach and extends the primary understanding of impact of formulation development of P(DL)LCL/PEO-PPO-PEO nanoparticles as carriers for SN-38.
ABSTRACT
Upon entering into the biological environments, the surface of the nanoparticles is immediately coated with proteins and form the so-called a protein corona due to which a nanoparticle changes its "synthetic" identity to a new "biological" identity. Different types of nanoparticles have different protein binding profiles, which is why they have different protein corona composition and therefore it cannot be said that there is a universal protein corona. The composition and amount of protein in the corona depends on the physical and chemical characteristics of the nanoparticles, the type of biological medium and the exposure time. Protein corona increases the diameter but also changes the composition of the surface of the nanoparticles and these changes affect biodistribution, efficacy, and toxicity of the nanoparticles.
ABSTRACT
The principal aim of this study was to analyze the chemical composition and qualitative and quantitative variability of essential oils obtained from seven naturally grown populations of the Pinus peuce Grisebach, Pinaceae in Kosovo. Plant materials were collected from three populations in the Sharri National Park and from four other populations in the Bjeshkët e Nemuna National Park, in Kosovo. Essential oils were obtained by steam distillation and analyzed by GC-FID (Gas Chromatography-Flame Ionization Detection) and GC-MS (Gas Chromatography-Mass Spectrometry). The results showed that the yield of essential oils (v/w dry weight) varied depending on the origin of population and the plant organs and ranged from 0.7 to 3.3%. In total, 51 compounds were identified. The main compounds were α-pinene (needles: 21.6-34.9%; twigs: 11.0-24%), ß-phellandrene (needles: 4.1-27.7; twigs: 29.0-49.8%), and ß-pinene (needles: 10.0-16.1; twigs: 6.9-20.7%). HCA (Hierarchical Cluster Analysis) and PCA (Principal Component Analyses) were used to assess geographical variations in essential oil composition. Statistical analysis showed that the analyzed populations are grouped in three main clusters which seem to reflect microclimatic conditions on the chemical composition of the essential oils.
