Journal: Frontiers in Pharmacology

Article Title: Platelet-membrane-coated nanoparticles enable safe and targeted thrombolysis with preserved neurovascular integrity

doi: 10.3389/fphar.2026.1825954

Figure Lengend Snippet: Fabrication and physicochemical characterization of PNP-rtPA thrombolytic nanoparticles. (A) Schematic illustration of the stepwise fabrication of recombinant tissue-type plasminogen activator (rtPA)–functionalized, platelet-membrane-coated poly lactic-co-glycolic acid (PLGA) nanoparticles. Perfluorohexane (PFH)-encapsulated PLGA nanoparticles were prepared, subsequently cloaked with isolated platelet membranes, and conjugated with DSPE-PEG-rtPA to obtain the final rtPA-PMC-PNP formulation. (B) Representative scanning-electron-microscopy (SEM) images showing the spherical morphology of rtPA-PMC-PNP at 200 nm and 50 nm scales. (C) Dynamic-light-scattering (DLS) analysis displaying the hydrodynamic-diameter distribution and ζ-potential profile of the nanoparticles. (D) Initial reaction velocity (ΔA405/min) of free rtPA, DSPE-PEG-rtPA, and PNP-rtPA determined from the linear phase of the chromogenic substrate assay. Data are presented as mean ± SEM (n = 6 independent replicates). (E) Time-dependent substrate cleavage kinetics measured as absorbance at 405 nm. Free rtPA, DSPE-PEG-rtPA, and PNP-rtPA were incubated with a chromogenic plasmin substrate, and absorbance was recorded at indicated time points (n = 6 independent replicates). (F,G) Western blot analysis of platelet-membrane proteins CXCR4, CD47, and ITGB3 in lipid-only, platelet-only, and platelet-lipid hybrid membranes under physiological (pH 7.4) and thrombus-mimicking (pH 6.8) conditions. Band intensities were normalized to Na + /K + -ATPase. Data are presented as mean ± S.E.M. (n = 6 biological replicates). (H) Time-dependent cumulative rtPA release/detachment from PNP-rtPA measured by ELISA under physiological (pH 7.4) and thrombus-mimicking (pH 6.8) conditions at 37 °C. (I) Quantification of clot-associated fluorescence intensity. DSPE-PEG-rtPA denotes rtPA conjugated to DSPE-PEG via amide coupling, whereas rtPA-PMC-PNP represents platelet membrane–coated, rtPA-conjugated, perfluorohexane-loaded PLGA nanoparticles. Data are presented as mean ± SEM (n = 6 independent replicates). Statistical analyses were performed using one-way ANOVA for single-time-point comparisons (panels D and I) and two-way repeated-measures ANOVA for time-course data (panels E and H), followed by appropriate post hoc tests. *P < 0.05, **P < 0.01.

Article Snippet: Recombinant tissue-type plasminogen activator (rtPA, Actilyse®, Boehringer Ingelheim) was used as received.

Techniques: Recombinant, Membrane, Isolation, Formulation, Electron Microscopy, Incubation, Western Blot, Enzyme-linked Immunosorbent Assay, Fluorescence

Journal: Frontiers in Pharmacology

Article Title: Platelet-membrane-coated nanoparticles enable safe and targeted thrombolysis with preserved neurovascular integrity

doi: 10.3389/fphar.2026.1825954

Figure Lengend Snippet: In vitro and in vivo thrombolytic efficacy of PNP-rtPA nanoparticles in a common carotid artery thrombosis model. (A) In vitro clot-lysis kinetics of PNP-rtPA and free recombinant tissue-type plasminogen activator (rtPA), showing comparable fibrinolytic activity between the two formulations. (B,C) Laser-speckle blood-flow imaging and representative photographs of thrombi in the common carotid artery (CCA) thromboembolism model at indicated time points after intravenous administration of vehicle, free rtPA, or PNP-rtPA. (D) Quantification of residual thrombus burden by weighing thrombosed CCA segments. (E,F) Hematoxylin-and-eosin (H,E) staining of carotid cross-sections and quantitative analysis of thrombus area following each treatment. Scale bar = 100 μm. (G) Plasma pharmacokinetics of human rtPA in mice after injection of free rtPA or PNP-rtPA, determined by ELISA. Data are presented as mean ± S.E.M. (n = 6 animals per group). Statistical analyses were performed using two-way repeated-measures ANOVA followed by Bonferroni’s multiple-comparison test for time-course data. *P < 0.05, **P < 0.01.

Article Snippet: Recombinant tissue-type plasminogen activator (rtPA, Actilyse®, Boehringer Ingelheim) was used as received.

Techniques: In Vitro, In Vivo, Lysis, Recombinant, Activity Assay, Imaging, Staining, Clinical Proteomics, Drug discovery, Injection, Enzyme-linked Immunosorbent Assay, Comparison