Exploring the dual impact of hydrocarbon chainlength and the role of piroxicam a conventional NSAID on soylecithin/ion pair amphiphiles mediated hybrid vesicles for brain – tumor targeted drug delivery

Impact of Ionic Liquids on the Physicochemical Behavior of Vesicles

The effects of two ionic liquids (ILs), 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) and 1-butyl-1-methyl pyrrolidinium tetrafluoroborate ([bmp]BF4), on a mixture of phospholipids (PLs) 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE), and 1,2-dipalmitoyl-sn-glycero-3-phosphoglycerol (DPPG) (6:3:1, M/M/M, 70% PL) in combination with 30 mol % cholesterol (CHOL) were investigated in the form of a solvent-spread monolayer and bilayer (vesicle). Surface pressure (π)-area (A) isotherm studies, using a Langmuir surface balance, revealed the formation of an expanded monolayer, while the cationic moiety of the IL molecules could electrostatically and hydrophobically bind to the PLs on the palisade layer. Turbidity, dynamic light scattering (size, ζ-potential, and polydispersity index), electron microscopy, small-angle X-ray/neutron scattering, fluorescence spectroscopy, and differential scanning calorimetric studies were carried out to evaluate the effects of IL on the structural organization of bilayer in the vesicles. The ILs could induce vesicle aggregation by acting as a "glue" at lower concentrations (<1.5 mM), while at higher concentrations, the ILs disrupt the bilayer structure. Besides, ILs could result in the thinning of the bilayer, evidenced from the scattering studies. Steady-state fluorescence anisotropy and lifetime studies suggest asymmetric insertion of ILs into the lipid bilayer. MTT assay using human blood lymphocytes indicates the safe application of vesicles in the presence of ILs, with a minimal toxicity of up to 2.5 mM IL in the dispersion. These results are proposed to have applications in the field of drug delivery systems with benign environmental impact.

An Amphiphilic Micromolecule Self-Assembles into Vesicles for Visualized and Targeted Drug Delivery

Described here is the first example of the construction of multifunctional drug delivery systems by employing an amphiphilic micromolecule. The intrinsic aggregation-induced emissive and tumor-targeting amphiphilic conjugate of β-d-galactose with tetraphenylethene (TPE-Gal), in which the hydrophobic TPE moiety spontaneously acts as the imaging chromophore and the hydrophilic Gal moiety spontaneously acts as the targeting ligand and galactosidase trigger, can self-assemble into fluorescent vesicles that can efficiently load both water-soluble and -insoluble anticancer drugs. In vitro and in vivo evaluations revealed that the pH/β-d-galactosidase dual-responsive doxorubicin (DOX)-loaded vesicles TPE-Gal@DOX exhibited good targeting effect and higher antitumor efficacy than free DOX. H&E staining analysis displayed remarkable necroses and weak cell proliferation in the tumor area and no toxicity to major organs, indicating the superior targeting antitumor therapeutic efficacy of TPE-Gal@DOX.