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Houston, TX, United States

Benod C.,Houston Methodist Research Institute HMRI | Villagomez R.,Houston Methodist Research Institute HMRI | Webb P.,Houston Methodist Research Institute HMRI
Journal of Steroid Biochemistry and Molecular Biology | Year: 2016

TLX (tailless receptor) is a member of the nuclear receptor superfamily and belongs to a class of nuclear receptors for which no endogenous or synthetic ligands have yet been identified. TLX is a promising therapeutic target in neurological disorders and brain tumors. Thus, regulatory ligands for TLX need to be identified to complete the validation of TLX as a useful target and would serve as chemical probes to pursue the study of this receptor in disease models. It has recently been proved that TLX is druggable. However, to identify potent and specific TLX ligands with desirable biological activity, a deeper understanding of where ligands bind, how they alter TLX conformation and of the mechanism by which TLX mediates the transcription of its target genes is needed. While TLX is in the process of escaping from orphanhood, future ligand design needs to progress in parallel with improved understanding of (i) the binding cavity or surfaces to target with small molecules on the TLX ligand binding domain and (ii) the nature of the TLX coregulators in particular cell and disease contexts. Both of these topics are discussed in this review. © 2015 Elsevier Ltd. All rights reserved.

Bruno G.,Houston Methodist Research Institute HMRI | Bruno G.,Polytechnic University of Turin | Geninatti T.,Houston Methodist Research Institute HMRI | Geninatti T.,University of Chinese Academy of Sciences | And 7 more authors.
Nanoscale | Year: 2015

General adoption of advanced treatment protocols such as chronotherapy will hinge on progress in drug delivery technologies that provide precise temporal control of therapeutic release. Such innovation is also crucial to future medicine approaches such as telemedicine. Here we present a nanofluidic membrane technology capable of achieving active and tunable control of molecular transport through nanofluidic channels. Control was achieved through application of an electric field between two platinum electrodes positioned on either surface of a 5.7 nm nanochannel membrane designed for zero-order drug delivery. Two electrode configurations were tested: laser-cut foils and electron beam deposited thin-films, configurations capable of operating at low voltage (≤1.5 V), and power (100 nW). Temporal, reproducible tuning and interruption of dendritic fullerene 1 (DF-1) transport was demonstrated over multi-day release experiments. Conductance tests showed limiting currents in the low applied potential range, implying ionic concentration polarization (ICP) at the interface between the membrane's micro- and nanochannels, even in concentrated solutions (≤1 M NaCl). The ability of this nanotechnology platform to facilitate controlled delivery of molecules and particles has broad applicability to next-generation therapeutics for numerous pathologies, including autoimmune diseases, circadian dysfunction, pain, and stress, among others. This journal is © The Royal Society of Chemistry 2015.

Minardi S.,Houston Methodist Research Institute HMRI | Corradetti B.,Houston Methodist Research Institute HMRI | Corradetti B.,Marche Polytechnic University | Taraballi F.,Houston Methodist Research Institute HMRI | And 7 more authors.
Annals of Biomedical Engineering | Year: 2016

The interaction of immune cells with biomaterials has been identified as a possible predictor of either the success or the failure of the implant. Among immune cells, macrophages have been found to contribute to both of these possible scenarios, based on their polarization profile. This proof-of-concept study aimed to investigate if it was possible to affect the response of macrophages to biomaterials, by the release of anti-inflammatory mediators. Towards this end, a collagen scaffold, integrated with poly(lactic-co-glycolic acid)—multistage silicon particles (MSV) composite microspheres (PLGA-MSV) releasing IL-4 was developed (PLGA-MSV/IL-4). Macrophages’ response to the scaffold was evaluated, both in vitro with rat bone-marrow derived macrophages, and in vivo in a rat subcutaneous pouch model. In vitro experiments revealed an overexpression of anti-inflammatory associated genes (Il-10, Mrc1, Arg1) at as soon as 48 h. The analysis of the cells that infiltrated the scaffold, revealed a prevalence of CD206+ macrophages at 24 h. Our strategy demonstrated that it is possible to tune the in vivo early response to biomaterials by the release of an anti-inflammatory cytokine, and that could contribute to accelerate the resolution of the inflammatory phase, benefiting a vast range of tissue engineering applications. © 2016 Biomedical Engineering Society

Minardi S.,Houston Methodist Research Institute HMRI | Minardi S.,CNR Institute of Science and Technology for Ceramics | Corradetti B.,Houston Methodist Research Institute HMRI | Corradetti B.,Marche Polytechnic University | And 7 more authors.
Small | Year: 2016

Scaffolds functionalized with delivery systems for the release of growth factors is a robust strategy to enhance tissue regeneration. However, after implantation, macrophages infiltrate the scaffold, eventually initiating the degradation and clearance of the delivery systems. Herein, it is hypothesized that fully embedding the poly(d,l-lactide-co-glycolide acid) microspheres (MS) in a highly structured collagen-based scaffold (concealing) can prevent their detection, preserving the integrity of the payload. Confocal laser microscopy reveals that non-embedded MS are easily internalized; when concealed, J774 and bone marrow-derived macrophages (BMDM) cannot detect them. This is further demonstrated by flow cytometry, as a tenfold decrease is found in the number of MS engulfed by the cells, suggesting that collagen can cloak the MS. This correlates with the amount of nitric oxide and tumor necrosis factor-α produced by J774 and BMDM in response to the concealed MS, comparable to that found for non-functionalized collagen scaffolds. Finally, the release kinetics of a reporter protein is preserved in the presence of macrophages, only when MS are concealed. The data provide detailed strategies for fabricating three dimensional (3D) biomimetic scaffolds able to conceal delivery systems and preserve the therapeutic molecules for release. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Geninatti T.,Houston Methodist Research Institute HMRI | Geninatti T.,University of Chinese Academy of Sciences | Bruno G.,Houston Methodist Research Institute HMRI | Bruno G.,Polytechnic University of Turin | And 8 more authors.
Biomedical Microdevices | Year: 2015

Fine control of molecular transport through microfluidic systems can be obtained by modulation of an applied electrical field across channels with the use of electrodes. In BioMEMS designed for biological fluids and in vivo applications, electrodes must be biocompatible, biorobust and stable. In this work, the analysis and characterization of platinum (Pt) electrodes integrated on silicon substrates for biomedical applications are presented. Electrodes were incorporated on the surface of silicon chips by adhesion of laminated Pt foils or deposited at 30°, 45° or 90° angle by e-beam or physical vapor (sputtering) methods. Electrical and physical properties of the electrodes were quantified and evaluated using electrical impedance spectroscopy and modelling of the electrode-electrolyte interfaces. Electrode degradation in saline solution at pH 7.4 was tested at room temperature and under accelerated conditions (90 °C), both in the presence and absence of an applied electrical potential. Degradation was quantified using atomic force microscopy (AFM) and inductively coupled plasma mass spectroscopy (ICP-MS). Biocompatibility was assessed by MTT proliferation assay with human dermal fibroblasts. Results demonstrated that the deposited electrodes were biocompatible with negligible material degradation and exhibited electrochemical behavior similar to Pt foils, especially for e-beam deposited electrodes. Finally, Pt electrodes e-beam deposited on silicon nanofabricated nanochannel membranes were evaluated for controlled drug delivery applications. By tuning a low applied electrical potential (<1.5 VDC) to the electrodes, temporal modulation of the dendritic fullerene 1 (DF-1) release from a source reservoir was successfully achieved as a proof of concept, highlighting the potential of deposited electrodes in biomedical applications. © Springer Science+Business Media New York 2015.

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