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