Author ContributionsThe manuscript was written through contributions of all authors. NDT, LCP, MRK1 (Karver), and MDS designed TF-targeted peptide sequences. MKK performed all conventional TEM. MKK conceived and designed the rat experiments and performed the surgeries. HAK assisted with the rat hemorrhage model. MKK and RHL conceived and designed the mouse experiments, with laser injury performed by RHL. DCG and BRD provided assistance with tissue processing and handling. MKK conceived, designed, and performed the TEG experiments. DCG provided additional assistance with TEGs. MDS and TDC performed CD spectroscopy. TDC performed cryo-TEM, SAXS, and WAXS. MRK1 synthesized all PAs. WB, EBP, LCP, NDT, TAP, SIS, MRK2 (Kibbe) helped guide the research. MKK, NDT, MRK2 interpreted all results. EBP assisted with statistical analysis. EBP and JRR performed CAC measurements. MKK prepared the initial draft of the manuscript. NDT and MRK2 critically revised the manuscript. MRK2, SIS, and BG provided oversight and funding of the entire project. All authors have given approval to the final version of the manuscript. Supporting InformationA table of the three letter codes, amino acid sequences, and corresponding Factor VII residues for the peptides incorporated into PA molecules; crystal structure models of the putative interaction sites of the targeting peptides on TF; HPLC-MS traces showing purity of synthesized PAs; cryogenic TEM of 25% SFE and 75% SBC-2 PA nanofibers; WAXS analysis of backbone, 25% SFE, and 75% SBC-2 PA nanofibers; CD spectroscopy of FKD and TQD PA nanofibers; fluorescent quantification of tested ratios of SFE and SBC-2 PA nanofibers; the critical aggregation concentration determinations for the 75% SBC-2, 25% SFE, and backbone PAs; and real-time localization of 75% SBC-2 in a mouse laser injury model. This material is available free of charge via the internet at http:// pubs.acs.org.

There is significant morbidity and mortality associated with smoke inhalation injury. Clinically relevant animal models are necessary for the continued investigation of the pathophysiology of inhalation injury and the development of therapeutics. The goal of our research was three-fold: 1) to develop a reproducible survival model of smoke inhalation injury in rats that closely resembled our previous mouse model, 2) validate the rat smoke inhalation injury model using a variety of laboratory techniques, and 3) compare and contrast the rat model with the well-established mouse model. Mice and rats were anesthetized, intubated, and placed in custom-built smoke chambers to passively inhale woodchip-generated smoke. Bronchoalveolar lavage fluid (BALF) and lung tissue were collected for a variety of confirmatory tests. Lung sections were stained using hematoxylin and eosin, lung edema was assessed with wet to dry (W/D) ratio, and inflammatory cell infiltration and cytokine elevation were evaluated using flow cytometry, immunohistochemistry, and ELISA. We confirmed that our mouse and rat models of smoke inhalation injury mimic the injury and immune response seen in humans after burn inhalation injury with protein elevation in BALF, pulmonary edema, neutrophil infiltration, and inflammatory cytokine elevation. Interestingly, rats mounted a more severe immunological response compared to mice. In summary, we successfully validated a reliable and clinically translatable survival model of lung injury and immune response in rats and mice and characterized the extent of this injury. These animal models allow for the continued study of smoke inhalation pathophysiology to ultimately develop a better therapeutic.

Atherosclerosis is the leading cause of death and disability around the world, with current treatments limited by neointimal hyperplasia. Our goal was to synthesize, characterize, and evaluate an injectable, targeted nanomaterial that will specifically bind to the site of arterial injury. Our target protein is fractalkine, a chemokine involved in both neointimal hyperplasia and atherosclerosis. We showed increased fractalkine staining in rat carotid arteries 24 h following arterial injury and in the aorta of low-density lipoprotein receptor knockout (LDLR-/-) mice fed a high-fat diet for 16 weeks. Three peptide amphiphiles (PAs) were synthesized: fractalkine-targeted, scrambled, and a backbone PA. PAs were ≥90% pure on liquid chromatography/mass spectrometry (LCMS) and showed nanofiber formation on transmission electron microscopy (TEM). Rats systemically injected with fractalkine-targeted nanofibers 24 h after carotid artery balloon injury exhibited a 4.2-fold increase in fluorescence in the injured artery compared to the scrambled nanofiber (p < 0.001). No localization was observed in the non-injured artery or with the backbone nanofiber. Fluorescence of the fractalkine-targeted nanofiber increased in a dose dependent manner and was observed for up to 48 h. These data demonstrate the presence of fractalkine after arterial injury and the localization of our fractalkine-targeted nanofiber to the site of injury and serve as the foundation to develop this technology further.

Herein the hypothesis that nitric oxide–bearing collagen‐targeted nanofibers will target vascular injury and inhibit neointimal hyperplasia in an atherosclerotic rat model is tested. Western blot confirms the apolipoprotein E (ApoE) knockout (‐/‐) status. Serum cholesterol increases threefold in Sprague Dawley (SD) ApoE‐/‐ versus wt SD rats (291.7 ± 22.3 vs 105.0 ± 3.6 mg dL−1, p < 0.05). Oxidative stress markers are elevated in SD ApoE‐/‐ vs wt SD strains (p = 0.002). Oil Red O staining shows lipid‐rich lesions in SD ApoE‐/‐ aortas. Transmission electron microscopy shows coassembled peptide amphiphiles (PA) form nanofibers. Fluorescence microscopy shows targeting of collagen‐binding peptide (CBP)‐S‐nitrosyl (SNO)‐PA nanofiber to arteries 20 min after injury, whereas uninjured carotid and nontargeted SNO‐PA nanofibers show minimal localization (3444.8 ± 282.0, 11.0 ± 2.3, and 451.4 ± 93.6 arbitrary units, respectively, p < 0.05). Two weeks after injury and injection, CBP‐SNO‐PA nanofibers inhibit neointimal hyperplasia by 67% versus injury alone (p < 0.0001). Intima/media (I/M) ratios are 0.3, 1.0, and 0.9 for CBP‐SNO‐PA nanofiber, scrambled SNO‐PA nanofiber, and injury alone, respectively (p < 0.0001). Results are durable out to 3 months (I/M 0.6 vs 1.4 for CBP‐SNO‐PA vs injury alone, p < 0.0001). Targeted drug‐eluting nanofibers localize to vascular injury, decrease neointimal hyperplasia after 2 weeks, and are durable out to 3 months in an atherosclerotic rat model.

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