The effects of Levothyroxine on the structure and dynamics of DPPC liposome: FTIR and DSC studies.
Levothyroxine (3,5,3',5'-tetraiodothyronine), which is a L-isomer of thyroxine T4 (L-T4), is a synthetic thyroid hormone that is biochemically and physiologically indistinguishable from endogenous T4. It is used as a thyroid hormone replacement drug to treat an underactive thyroid gland. The interaction of L-T4, with zwitterionic dipalmitoyl phosphatidylcholine (DPPC) multilamellar liposomes (MLVs) was studied in the presence (1 mol%, 3 mol%, 6 mol%, 9 mol%, 15 mol%, 24 mol% and 30 mol%) and absence of L-T4 by using two different non-invasive techniques; Fourier Transform Infrared (FTIR) spectroscopy and Differential Scanning Calorimetry (DSC). The results show that L-T4 does perturb the phase transition profile by either decreasing the main transition temperature (Tm) and enthalpy (ΔH) or increasing the width at half height (ΔT½). That means; it changes the physical properties of DPPC bilayers. Addition of L-T4 into pure DPPC liposomes shifts the phase transition to lower temperature, disorder the system in gel phase with opposite effect in liquid-crystalline phase and increases the dynamics of the system in both phases and also causes dehydration of the groups of lipids and the water molecules around.
['Aleskndrany|Abeer|A|', 'Sahin|Ipek|I|']
D015060:1,2-Dipalmitoylphosphatidylcholine D002152:Calorimetry, Differential Scanning D004305:Dose-Response Relationship, Drug D008081:Liposomes D044367:Phase Transition D017550:Spectroscopy, Fourier Transform Infrared D013696:Temperature D013816:Thermodynamics D013974:Thyroxine D014867:Water
Levothyroxine Dipalmitoyl phosphatidylcholine Fourier transform infrared Differential scanning calorimetry Drug-membrane interaction