In Vivo Assessment of Thermosensitive Liposomes for the Treatment of Port Wine Stains by Antifibrinolytic Site-Specific Pharmaco-Laser Therapy
Mingjuan Li,
M. Ingmar van Raath,
Shervin Khakpour,
Ahmet Seçilir,
Bart C. Sliggers,
Xuan Huang,
Baoyue Ding,
Gert Storm,
René R. van der Hulst,
Anton I.P.M. de Kroon,
Michal Heger
Affiliations
Mingjuan Li
Department of Pharmaceutics, Jiaxing Key Laboratory for Photonanomedicine and Experimental Therapeutics, College of Medicine, Jiaxing University, Jiaxing 314001, Zhejiang, China
M. Ingmar van Raath
Department of Pharmaceutics, Jiaxing Key Laboratory for Photonanomedicine and Experimental Therapeutics, College of Medicine, Jiaxing University, Jiaxing 314001, Zhejiang, China
Shervin Khakpour
Membrane Biochemistry and Biophysics, Institute of Biomembranes, Utrecht University, 3584 CH Utrecht, The Netherlands
Ahmet Seçilir
Membrane Biochemistry and Biophysics, Institute of Biomembranes, Utrecht University, 3584 CH Utrecht, The Netherlands
Bart C. Sliggers
Department of Medical Innovation and Development, Amsterdam University Medical Centers, location AMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
Xuan Huang
Department of Pharmaceutics, Jiaxing Key Laboratory for Photonanomedicine and Experimental Therapeutics, College of Medicine, Jiaxing University, Jiaxing 314001, Zhejiang, China
Baoyue Ding
Department of Pharmaceutics, Jiaxing Key Laboratory for Photonanomedicine and Experimental Therapeutics, College of Medicine, Jiaxing University, Jiaxing 314001, Zhejiang, China
Gert Storm
Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CG Utrecht, The Netherlands
René R. van der Hulst
Department of Plastic, Reconstructive, and Hand Surgery, Maastricht University Medical Center, Maastricht University, 3229 HX Maastricht, The Netherlands
Anton I.P.M. de Kroon
Membrane Biochemistry and Biophysics, Institute of Biomembranes, Utrecht University, 3584 CH Utrecht, The Netherlands
Michal Heger
Department of Pharmaceutics, Jiaxing Key Laboratory for Photonanomedicine and Experimental Therapeutics, College of Medicine, Jiaxing University, Jiaxing 314001, Zhejiang, China
Antifibrinolytic site-specific pharmaco-laser therapy (SSPLT) is an experimental treatment modality for refractory port wine stains (PWS). Conceptually, antifibrinolytic drugs encapsulated in thermosensitive liposomes are delivered to thrombi that form in semi-photocoagulated PWS blood vessels after conventional laser treatment. Local release of antifibrinolytics is induced by mild hyperthermia, resulting in hyperthrombosis and complete occlusion of the target blood vessel (clinical endpoint). In this study, 20 thermosensitive liposomal formulations containing tranexamic acid (TA) were assayed for physicochemical properties, TA:lipid ratio, encapsulation efficiency, and endovesicular TA concentration. Two candidate formulations (DPPC:DSPE-PEG, DPPC:MPPC:DSPE-PEG) were selected based on optimal properties and analyzed for heat-induced TA release at body temperature (T), phase transition temperature (Tm), and at T > Tm. The effect of plasma on liposomal stability at 37 °C was determined, and the association of liposomes with platelets was examined by flow cytometry. The accumulation of PEGylated phosphocholine liposomes in laser-induced thrombi was investigated in a hamster dorsal skinfold model and intravital fluorescence microscopy. Both formulations did not release TA at 37 °C. Near-complete TA release was achieved at Tm within 2.0–2.5 min of heating, which was accelerated at T > Tm. Plasma exerted a stabilizing effect on both formulations. Liposomes showed mild association with platelets. Despite positive in vitro results, fluorescently labeled liposomes did not sufficiently accumulate in laser-induced thrombi in hamsters to warrant their use in antifibrinolytic SSPLT, which can be solved by coupling thrombus-targeting ligands to the liposomes.
