RESUMEN
The vascular endothelium from individual organs is functionally specialized, and it displays a unique set of accessible molecular targets. These serve as endothelial cell receptors to affinity ligands. To date, all identified vascular receptors have been proteins. Here, we show that an endothelial lung-homing peptide (CGSPGWVRC) interacts with C16-ceramide, a bioactive sphingolipid that mediates several biological functions. Upon binding to cell surfaces, CGSPGWVRC triggers ceramide-rich platform formation, activates acid sphingomyelinase and ceramide production, without the associated downstream apoptotic signaling. We also show that the lung selectivity of CGSPGWVRC homing peptide is dependent on ceramide production in vivo. Finally, we demonstrate two potential applications for this lipid vascular targeting system: i) as a bioinorganic hydrogel for pulmonary imaging and ii) as a ligand-directed lung immunization tool against COVID-19. Thus, C16-ceramide is a unique example of a lipid-based receptor system in the lung vascular endothelium targeted in vivo by circulating ligands such as CGSPGWVRC.
Asunto(s)
COVID-19 , Humanos , Ligandos , COVID-19/metabolismo , Ceramidas/metabolismo , Pulmón/metabolismo , Endotelio Vascular/metabolismo , Receptores de Superficie Celular/metabolismo , Proteínas Portadoras/metabolismo , Esfingomielina Fosfodiesterasa/metabolismoRESUMEN
BACKGROUND: Complex medication regimens, often present in heart failure with preserved ejection fraction, may increase the risk of adverse drug effects and harm. We sought to characterize this complexity by determining the prevalence of polypharmacy, potentially inappropriate medications, and therapeutic competition (where a medication for 1 condition may worsen another condition) in 1 of the few dedicated heart failure with preserved ejection fraction programs in the United States. METHODS: We conducted chart review on 231 patients with heart failure with preserved ejection fraction seen in the University of Michigan's Heart Failure with Preserved Ejection Fraction Clinic between July 2016 and September 2019. We recorded: 1) standing medications to determine the presence of polypharmacy, defined as ≥10 medications; 2) potentially inappropriate medications based on the 2016 American Heart Association Scientific Statement on drugs that pose a major risk of causing or exacerbating heart failure, the 2019 Beers Criteria update, or a previously described list of medications associated with geriatric syndromes; and 3) competing conditions and subsequent medications that could create therapeutic competition. RESULTS: The prevalence of polypharmacy was 74%, and the prevalence of potentially inappropriate medications was 100%. Competing conditions were present in 81% of patients, of whom 49% took a medication that created therapeutic competition. CONCLUSION: In addition to confirming that polypharmacy was highly prevalent, we found that potentially inappropriate medications and therapeutic competition were also frequently present. This supports the urgent need to develop patient-centered approaches to mitigate the negative effects of complex medication regimens endemic to adults with heart failure with preserved ejection fraction.
Asunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/etiología , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/tratamiento farmacológico , Polifarmacia , Lista de Medicamentos Potencialmente Inapropiados/estadística & datos numéricos , Anciano , Femenino , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Volumen Sistólico , Estados UnidosRESUMEN
A major challenge of targeted molecular imaging and drug delivery in cancer is establishing a functional combination of ligand-directed cargo with a triggered release system. Here we develop a hydrogel-based nanotechnology platform that integrates tumor targeting, photon-to-heat conversion, and triggered drug delivery within a single nanostructure to enable multimodal imaging and controlled release of therapeutic cargo. In proof-of-concept experiments, we show a broad range of ligand peptide-based applications with phage particles, heat-sensitive liposomes, or mesoporous silica nanoparticles that self-assemble into a hydrogel for tumor-targeted drug delivery. Because nanoparticles pack densely within the nanocarrier, their surface plasmon resonance shifts to near-infrared, thereby enabling a laser-mediated photothermal mechanism of cargo release. We demonstrate both noninvasive imaging and targeted drug delivery in preclinical mouse models of breast and prostate cancer. Finally, we applied mathematical modeling to predict and confirm tumor targeting and drug delivery. These results are meaningful steps toward the design and initial translation of an enabling nanotechnology platform with potential for broad clinical applications.
Asunto(s)
Antineoplásicos/administración & dosificación , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/tratamiento farmacológico , Modelos Animales de Enfermedad , Imagen Multimodal , Nanotecnología , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/tratamiento farmacológico , Animales , Sistemas de Liberación de Medicamentos , Femenino , Rayos Infrarrojos , Imagen por Resonancia Magnética , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Resonancia por Plasmón de SuperficieRESUMEN
We report a unique approach in which living cells direct their integration into 3D solid-state nanostructures. Yeast cells deposited on a weakly condensed lipid/silica thin film mesophase actively reconstruct the surface to create a fully 3D bio/nano interface, composed of localized lipid bilayers enveloped by a lipid/silica mesophase, through a self-catalyzed silica condensation process. Remarkably, this integration process selects exclusively for living cells over the corresponding apoptotic cells (those undergoing programmed cell death), via the development of a pH gradient, which catalyzes silica deposition and the formation of a coherent interface between the cell and surrounding silica matrix. Added long-chain lipids or auxiliary nanocomponents are localized within the pH gradient, allowing the development of complex active and accessible bio/nano interfaces not achievable by other synthetic methods. Overall, this approach provides the first demonstration of active cell-directed integration into a nominally solid-state three-dimensional architecture. It promises a new means to integrate "bio" with "nano" into platforms useful to study and manipulate cellular behavior at the individual cell level and to interface living organisms with electronics, photonics, and fluidics.
Asunto(s)
Lípidos/química , Microscopía Electrónica de Rastreo/métodos , Nanoestructuras/química , Dióxido de Silicio/química , Materiales Biocompatibles , Técnicas Biosensibles , Concentración de Iones de Hidrógeno , Membrana Dobles de Lípidos , Ensayo de Materiales , Microscopía Confocal/métodos , Microscopía Fluorescente/métodos , Nanotecnología/métodos , Saccharomyces cerevisiae/metabolismo , Dispersión de Radiación , Propiedades de SuperficieRESUMEN
A simple procedure for introducing functional exogenous membrane-bound proteins to viable cells encapsulated within a lipid templated silica nanostructure is described. In one method, bacteriorhodopsin (bR) was added directly to a Saccharomyces cerevisiae solution along with short zwitterionic diacylphosphatidylcholines (diC(6) PC) and mixed with equal volumes of a sol precursor solution. Alternatively, bR was first incorporated into liposomes (bR-proteoliposomes) and then added to an S. cerevisiae solution with diC(6) PC, and this was followed by mixing with sol precursor solution. Films prepared from bR added directly to diC(6) PC resulted in bR localization near S. cerevisiae cells in a disordered and diffuse fashion, while films prepared from bR-proteoliposomes added to the diC(6) PC/yeast solution resulted in preferential localization of bR near yeast cell surfaces, forming bR-containing multilayer vesicles. Importantly, bR introduced via proteoliposomes was observed to modulate pH gradients developed at the cell surface, demonstrating both retained functionality and preferential orientation. Localization of liposome lipid or bR did not occur around neutrally charged latex beads acting as cell surrogates, demonstrating that living cells actively organize the multilayered lipid during evaporation-induced self-assembly. We expect this simple procedure for introducing functional and oriented membrane-bound proteins to the surface of cells to be general and adaptable to other membrane-bound proteins. This advance may prove useful in fundamental studies of membrane protein function and cell-cell signaling and in imparting non-native characteristics to arbitrary cells.