Preparation of L-Glutamine Loaded Liposomes for Drug Delivery to Erythrocytes
Gokce Alp1 and Yesim Oztas2
1Department of Chemical Engineering, Faculty of Engineering, Hacettepe University, Ankara, Turkey; 2Department of Medical Biochemistry, Faculty of Medicine, Hacettepe University, Ankara, Turkey
Abstract: Sickle cell disease (SCD) is a mortal chronic disease caused by a point mutation in the β chain gene in the hemoglobin A (HbA) molecule. Erythrocyte polymerization in SCD is mostly seen as a result of the decrease in the amount of ions and water in the cell, i.e. dehydration and deoxygenation of erythrocytes. Deoxygenated and dehydrated erythrocytes become susceptible to clustering, causing clogging of blood vessels which then leads to crisis. Therefore, development of a new treatment method that can effectively prevent deoxygenation of erythrocytes or reduce the oxidative stress of sickle erythrocytes is one of the important issues. The aim of this study is to obtain a new lipid-based drug delivery system that will further be used for decreasing the oxidative stress of sickle erythrocytes. For the purpose, in this study, L-Glutamine (L-Gln) loaded liposomal drug delivery system composed of L-α-Phosphatidylinositol (PI) is prepared. Also, effect of encapsulated amount of L-Gln in liposomes is investigated. Liposomes are prepared via thin-film rehydration method. Characterizations of liposomes are implemented with pH measurements, zeta potential and size measurements. Erythrocytes and liposomes are incubated at 37ºC for 1 and 3 hours. Interactions between the erythrocytes and liposomes are investigated via optical microscopy and hemolysis experiments. The size and zeta potential of unloaded PI liposomes are determined as 89.01 nm with a polydispersity index of 0.438 and -23.4 ± 1.5 mV, respectively. Sizes of L-Gln loaded liposomes are obtained as 126.7, 148.6 and 197.2 nm for 20 mM, 40 mM and 60 mM of L-Gln, respectively. From the optical microscopy images, it is determined that as incubation period of erythrocytes and liposomes are increased, more liposomes are interacted with erythrocytes. Also, as L-Gln amount is increased within the liposomes, it was observed that erythrocytes preserve their morphology.
Overall, with this study, it can be concluded that L-Glutamine loaded liposomes can be used as a new drug delivery platform for erythrocytes. Moreover, the results of this study provide preliminary steps and promising results for design and development of a lipid-based drug carrier system to be used in the treatment of specific erythrocyte-based diseases such as sickle-cell disease.
Keywords: Liposomes, Lipid-based carriers, L-Glutamine, Deoxygenation, Red blood cells, Sickle cell disease.