Thrombolysis by Recombinant Tissue Plasminogen Activator-Immobilized Magnetic Nanoparticles Coated With Chitosan: A Comparative Study Publisher



Banikarimi S P ; Tafti S H A ; Soleimani M ; Heirani Tabasi A ; Maleki H ; Baharifar H ; Khoshnevisan K
Source: In Vitro Models Published:2026

Abstract

Objective: This study explores the thrombolytic potential of recombinant tissue plasminogen activator (rtPA) immobilized on chitosan-coated magnetic nanoparticles (rtPA-CS-MNPs) in comparison with free rtPA and commercialized MNPs (CMNPs). The objective was to evaluate whether MNPs immobilization enhances stability, prolongs enzymatic activity, and improves clot dissolution efficiency under in vitro conditions. Methods: rtPA was immobilized onto CS-coated MNPs via covalent bonding. Characterization was performed using dynamic light scattering (DLS) for size and zeta potential (ZP) analysis, Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). In vitro thrombolysis assays were conducted using fibrin clots prepared from human plasma. Comparative analysis was performed between rtPA-CS-MNPs, rtPA-CMNPs, and free rtPA. Results: rtPA-CS-MNPs demonstrated sustained enzymatic activity with consistently higher OD values compared to free rtPA and CMNPs. DLS and ZP of rtPA-CS-MNPs were around 152 and − 9, respectively. FTIR results confirmed that CS successfully coated MNPs as well as rtPA immobilized into CS-MNPs. TEM images exhibited mainly spherical MNPs in the 20–50 nm range. The findings suggested that MNPs, CS, and the administered dose of rtPA are safe for potential in vivo applications. The immobilized formulation demonstrated prolonged stability, reduced degradation, and enhanced clot-dissolution efficacy over 24 h. Blank controls confirmed that activity was attributable to rtPA immobilization rather than nanoparticle interference. Conclusion: The findings indicate that rtPA-CS-MNPs provide superior thrombolytic activity compared to free rtPA, with advantages in stability and sustained release. This comparative study highlights the potential of CS-coated MNPs as a promising platform for controlled and efficient thrombolytic therapy. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2026.