Biology subjects

Hoyt, K.

Publications and source records attributed to Hoyt, K..

3 recordsLinked to original sources

bioRxiv2022

Significantly amplified photoacoustic effect for silica-coated gold nanoparticles by interface heat transfer mechanisms

Plasmonic gold nanoparticles (AuNPs) are effective photoacoustic (PA) signal agents and have found important biomedical applications. The silica coating on the surface of AuNPs showed enhanced PA efficiency, however, the PA amplification mechanism remains unclear. Here, we systematically studied the silica coating effect on PA generation of AuNPs under different laser pulse durations. We experimentally demonstrated up to 4-fold PA amplification under thin silica coating (<5 nm) and a picosecond laser excitation. The theoretical model further suggests that the PA amplification originates from two interface heat transfer mechanisms including 1) the enhanced interface thermal conductance on the silica-water interface and 2) the electron-phonon energy transfer channel on the gold/silica interface. This study discovers a regime of large PA amplification and provides a new rationale for plasmonic nanoparticle design to achieve better PA efficiency.

bioengineering↗

bioRxiv2022

Optical Modulation of Blood-Brain-Tumor Barrier Permeability Enhances Drug Delivery in Diverse Preclinical Glioblastoma Models

Glioblastoma multiforme (GBM) is the most prevalent malignant tumor in the central nervous system. It has diverse phenotypes, including diffuse single-cell infiltration in which the tumor cells co-opt the normal microvasculature, and the neovascularization of an expanding tumor mass. The blood-brain-tumor barrier (BBTB) is a significant obstacle to GBM treatment and restricts entry of most FDA-approved effective oncology drugs. Herein, we report that picosecond laser excitation of vascular-targeted plasmonic gold nanoparticles (AuNPs) can non-invasively and reversibly modulate the BBTB permeability (optoBBTB). OptoBBTB enhances the delivery of paclitaxel (Taxol) in two genetically engineered glioma models (GEMM) that span the spectrum of GBM phenotypes. OptoBBTB followed by Taxol delivery effectively suppresses tumor growth and prolongs the survival time of both GEMM. Moreover, our results raise the possibility that paclitaxel, which is amongst the most widely used oncology drugs because of its proven efficacy but has been abandoned for GBM following its failure to efficacy in early phase clinical trials due to poor blood-brain barrier (BBB) penetration, could now be reconsidered in combination with strategies to increase BBB permeability. In summary, optoBBTB is a novel and effective approach to increase the delivery of therapeutics with limited BBB permeability to treat neoplastic and non-neoplastic brain diseases.

bioengineering↗

bioRxiv2020

Intercellular Arc signaling regulates vasodilation

Injury responses require communication between different cell types in the skin. Sensory neurons contribute to inflammation and can secrete signaling molecules that affect non-neuronal cells. Despite the pervasive role of translational regulation in nociception, the contribution of activity-dependent protein synthesis to inflammation is not well understood. To address this problem, we examined the landscape of nascent translation in DRG neurons treated with inflammatory mediators using ribosome profiling. We identified the activity-dependent gene, Arc, as a target of privileged translation in vitro and in vivo. Inflammatory cues promote local translation of Arc in the skin. Arc deficient mice display exaggerated paw temperatures and vasodilation in response to an inflammatory challenge. Since Arc has recently been shown to be released from neurons in extracellular vesicles, we hypothesized that intercellular Arc signaling regulates the inflammatory response in skin. We found that the excessive thermal responses and vasodilation observed in Arc defective mice are rescued by injection of Arc-containing extracellular vesicles into the skin. Our findings suggest that activity-dependent production of Arc in afferent fibers regulates neurogenic inflammation through intercellular signaling. HIGHLIGHTSO_LIRibosome profiling identifies Arc as a target of activity-dependent translation C_LIO_LIArc is present in the DRG, spinal cord, and skin C_LIO_LIInduced Arc biosynthesis in skin requires the presence of afferent fibers C_LIO_LIArc-deficient mice have exaggerated inflammation that is rescued by Arc-containing extracellular vesicles C_LI

neuroscience↗