PLGA NPs and evaluated laser thrombolysis capabilities and photomechanical drug delivery in a blood clot. The tPA encapsulated PLGA and PLGA/ CS nanoparticles were fabricated via the W/O/W double emulsion solvent

The purpose of this study is to prepare cationic nanoparticles (NPs) by coating chitosan (CS) on the surface of PLGA NPs and evaluated laser thrombolysis capabilities and photomechanical drug delivery in a blood clot. The tPA encapsulated PLGA and PLGA/ CS nanoparticles were fabricated via the W/O/W double emulsion solvent evaporation surface coating method. The characteristics of NPs are determined by laser light scattering and zeta potential measurement. The CS coating was confirmed by zeta potential and fourier transform infrared spectroscopy. The surface morphology of NPs was also studied by transmition scanning microscopy. Differential scanning calorimetry was used for thermal analysis. In vitro drug release experiments of tPA encapsulated PLGA and PLGA/CS are determined by HPLC and showed a sustained release profile for three days with little initial burst release for PLGA/CS NPs. The mean particle size and encapsulation efficiency of tPA NPs were in the range of 280-360 nm and 46.7%±1.56, 50.8%±1.09, respectively. The encapsulation efficiency and the particles size were increased as a result of coating with CS. The release kinetics was evaluated by fitting the experimental data to standard release equations (Higuchie equation). This model was used to find the best fit for NPs. The results showed that the NPs for the highest weight percentages of digested clot is PLGA/CS NPs. Compared with tPA, the NPs significantly increased the weight of digested clots in the following order, PLGA/CS NPs (21.6%) > PLGA NPs (15.54%) > tPA (8.05%). Also, the thrombolysis process can be enhanced by delivering tPA into clot during laser ablation based on the photomechanical effect due to optical cavitation bubbles. Photomechanical drug delivery and the NPs used in this experiment showed that they can significantly thrombolysis in vitro in this model, and may be useful for acute myocardial infarction (AMI). M.Mahmoodi, Laser and Nanobiophotonics Lab, Biomaterial Group, Faculty of Biomed. Engin., Amirkabir University of Technology, Tehran and Islamic Azad University of Yazd, Faculty of Eng., Material Group, Yazd, Iran , ([email protected]) M.E.Khosroshahi, Laser and Nanobiophotonics Lab, Biomaterial Group, Faculty of Biomed. Engin., AmirkabirUniversity of Technology, Tehran, Iran, ([email protected]) . F.Atyabi, Novel Drug Delivery Systems Lab, Faculty of Pharmacy, Medical Sciences, University of Tehran, PO Box 14155-6451, Iran, ([email protected]) Keywords—Frequency doubled Nd:YAG, Laser thrombolysis, PLGA/CS Nanoparticles, Tissue Plasminogen Activator