A mechanistic study of the permeation kinetics through biomembrane models: Gemcitabine–phospholipid bilayer interaction

Improved In Vitro Anti-Tumoral Activity, Intracellular Uptake and Apoptotic Induction of Gemcitabine-Loaded Pegylated Unilamellar Liposomes

“…18 19 Furthermore, liposomal carriers can provide a passive targeting to certain tumors due to the discontinuous structure of tumoral endothelium of capillaries that, in combination with impaired lymphatics, allows an efficient extravasation and accumulation of colloidal carriers with a mean size ≤200 nm. 20 It has been recently demonstrated 21 that gemcitabine can interact with phospholipid bilayers of different composition and that its permeation kinetics through biomembranes depends on the physicochemical drug situation (protonation/deprotonation). In this case, the use of pegylated liposomal carriers not only protects the drug from changes of biological environments, thus modulating per se the type of interaction with biological substrates, but also improves the intracellular delivery of encapsulated drugs, 22 this aspect is of particular importance in all cases where an intracellular action site is recognized such as in the case of gemcitabine.…”

Enhancement of gemcitabine affinity for biomembranes by conjugation with squalene: Differential scanning calorimetry and Langmuir–Blodgett studies using biomembrane models

“…In addition, to gaining more information about the interaction prodrug/phospholipid, the experiments have also been carried out using squalene (2,6,10,15,19,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene) and squalene acid (1,1 ,2-tris-nor-squalenic acid) used to allow the conjugation with gemcitabine (Scheme 1). Differential scanning calorimetry (DSC) is a nonperturbative technique largely employed to detect the effects exerted by biomolecules on the lipid bilayers of a cell-like membrane in the processes of entrapment and release inside lipid vesicles [9,10]. Lipid membranes (multilamellar vesicles, MLV, are usually employed as synthetic simplified biomembranes models) undergo a sharp phase transition from an ordered gel-like structure (L β ) to a disordered fluid-like structure (L α ).…”

In Vitro Evaluation of Enrofloxacin-Loaded MLV Liposomes

“…Encapsulation of antibiotics in liposomes has a number of advantages (New 1995). Following different preparation methodologies and liposomes types such as large unilamellar vesicles (LUVs) and multilamellar vesicles (MLVs) show different encapsulation capacity, stability, and release properties when encapsulated antibiotics and other drugs into these vesicles (Maurer et al 1998;Grabielle-Madelmont, Lesieur, and Ollivon et al 2003;Castelli, Raudino, and Fresta et al 2005). The size and number of lamellae of the vesicles also are important for the encapsulation of drugs in liposomes.…”