Physical and functional characterization of the SP nanoparticles. (A) Schematic of the manufacturing process for SP nanoparticle with lipids and lipid-peptide conjugates using the thin film rehydration followed by extrusion methodology. (B) Dynamic Light Scattering characterization and (C) Cryo-transmission electron microscopy (Cryo-TEM) imaging of SP nanoparticles indicates a diameter of approximately 150 to 200 nm. (D-E) Representative fluorescence microscopy images and quantitative analysis of imaging data from BioFlux microfluidics studies with platelet suspensions indicate that depletion of platelets from 200 000 per μL (Plt-200K) to 20 000 per μL (Plt-20K) results in drastic reduction of platelet coverage of collagen-coated microfluidic channel surface. Treatment of Plt-20K with CP does not rescue this whereas the treatment of Plt-20K with SP nanoparticles significantly rescues platelet recruitment and coverage on the collagen-coated channel surface (colocalization of Rhodamine B-labeled red fluorescent SP with calcein-stained green fluorescent platelets appear yellow). The particle/platelet ratio was 1000:1. Means ± SD are represented. Statistical analysis was performed using a one-way ANOVA with Tukey's correction. ∗∗P ≤ .01; ∗∗∗P ≤ .001; ∗∗∗∗P ≤ .0001. ns, not significant.