Glioblastoma multiforme (GBM) is the most prevalent malignant brain tumor, with an average survival time of 14 to 20 months. Its capacity to invade brain parenchyma leads to the failure of conventional treatments and subsequent tumor recurrence. Recent studies have explored new therapeutic strategies using a chemoattracting gradient to attract GBM cells into a soft hydrogel trap where they can be exposed to higher doses of radiation or chemotherapy.
View Article and Find Full Text PDFGrade IV multiforme glioblastoma (GBM) is an aggressive cancer that remains incurable due to the GBM cells invading and proliferating in the surrounding healthy tissues, even after tumor resection. A new therapeutic paradigm to treat GBM is to attract and accumulate GBM cells in a macroporous hydrogel inserted in the surgical cavity after tumor resection, followed by a targeted high dose of radiotherapy. This work presents a molding-based method to prepare macroporous hydrogels composed of sodium alginate and chitosan, homogeneously mixed in solution using sodium bicarbonate, and subsequently crosslinked with genipin and calcium chloride.
View Article and Find Full Text PDFWe report a facile green hydrothermal synthesis (HTS) of monoliths of hydrogels decorated with noble metal nanoparticles (NPs). The one-pot approach requires solely water, a polysaccharide able to form a hydrogel, and a salt precursor (M-containing) for the metal NPs. The polysaccharide fulfills three roles: (i) it acts as the reducing agent of M to M under hydrothermal conditions, (ii) it stabilizes NPs surfaces, and (iii) it forms a hydrogel scaffold in which the metal NPs are embedded.
View Article and Find Full Text PDFEnsuring good definition of scaffolds used for 3D cell culture is a prominent challenge that hampers the development of tissue engineering platforms. Since dextran repels cell adhesion, using dextran-based materials biofunctionalized through a bottom-up approach allows for precise control over material definition. Here, we report the design of dextran hydrogels displaying a fully interconnected macropore network for the culture of vascular spheroids .
View Article and Find Full Text PDFGlioblastoma (GBM) accounts for half of all central nervous system tumors. Once the tumor is removed, many GBM cells remain present near the surgical cavity and infiltrate the brain up to a distance of 20-30 mm, resulting in recurrence a few months later. GBM remains incurable due to the limited efficiency of current treatments, a result of the blood-brain barrier and sensitivity of healthy brain tissues to chemotherapy and radiation.
View Article and Find Full Text PDFWe report an additive-free one-pot hydrothermal synthesis of Au, Ag, Pd, and alloy AuPd nanoparticles (NPs) anchored on commercial polyurethane (PU) foams. While unable to reduce the precursor metal salts at room temperature, PU is able to serve as a reducing agent under hydrothermal conditions. The resulting NP@PU sponge materials perform comparably to reported state-of-the-art reduction catalysts, and are additionally very well suited for use in semi-automated synthesis: the NP anchoring is strong enough and the support flexible enough to be used as a 'catalytic sponge' that can be manipulated with a robotic arm, , be repeatedly dipped into and drawn out of solutions, wrung out, and re-soaked.
View Article and Find Full Text PDFLong-term delivery is a successful strategy used to reduce the adverse effects of monoclonal antibody (mAb)-based treatments. Macroporous hydrogels and affinity-based strategies have shown promising results in sustained and localized delivery of the mAbs. Among the potential tools for affinity-based delivery systems, the de novo designed Ecoil and Kcoil peptides are engineered to form a high-affinity, heterodimeric coiled-coil complex under physiological conditions.
View Article and Find Full Text PDFIn this study, we developed and characterized various open-cell composite scaffolds for bone regeneration. These scaffolds were made from Polylactic acid (PLA) as the scaffold matrix biopolymeric phase, and chitosan (CS) and chitosan-grafted-PLA (CS-g-PLA) copolymer as the dispersed biopolymeric phase. As a first step, successful grafting of PLA onto CS backbone was executed and confirmed by both FTIR and XPS.
View Article and Find Full Text PDFMacroporous hydrogels possess a vast potential for various applications in the biomedical field. However, due to their large pore size allowing for unrestricted diffusion in the macropore network, macroporous hydrogels alone are not able to efficiently capture and release biomolecules in a controlled manner. There is thus a need for biofunctionalized, affinity-based gels that can efficiently load and release biomolecules in a sustained and controlled manner.
View Article and Find Full Text PDFHerein, we report a novel method to synthesize metal nanoparticle-shells (NP-shells) and continuous shells at the liquid/liquid interface, an interfacial reaction in an Ouzo emulsion. Ouzo emulsions spontaneously form submicronic droplets with a narrow size distribution, without any energy-intensive process. The Ouzo system in this work comprises water, tetrahydrofuran (THF) and butylated hydroxytoluene (BHT), and forms BHT-rich droplets (∼100 nm).
View Article and Find Full Text PDFReactive thermoplastics matrices offer ease of processing using well-known molding techniques (such as Resin Transfer Molding) due to their initially low viscosity. For Polyamide 6 (PA6)/glass composites, the hydroxyl groups on the glass surface slow down the anionic ring-opening polymerization (AROP) reaction, and can ultimately inhibit it. This work aims to thoroughly control the hydroxyl groups and the surface chemistry of glass particulates to facilitate in situ AROP-an aspect that has been barely explored until now.
View Article and Find Full Text PDFGlioblastoma multiforme is a type of brain cancer associated with a very low survival rate since a large number of cancer cells remain infiltrated in the brain despite the treatments currently available. This work presents a macroporous hydrogel trap, destined to be implanted in the surgical cavity following tumor resection and designed to attract and retain cancer cells, in order to eliminate them afterward with a lethal dose of stereotactic radiotherapy. The biocompatible hydrogel formulation comprises sodium alginate (SA) and chitosan (CHI) bearing complementary electrostatic charges and stabilizing the gels in saline and cell culture media, as compared to pristine SA gels.
View Article and Find Full Text PDFGlioblastoma multiforme (GBM) is a grade IV glioma considered the most fatal cancer of the central nervous system (CNS), with less than a 5% survival rate after five years. The tumor heterogeneity, the high infiltrative behavior of its cells, and the blood-brain barrier (BBB) that limits the access of therapeutic drugs to the brain are the main reasons hampering the current standard treatment efficiency. Following the tumor resection, the infiltrative remaining GBM cells, which are resistant to chemotherapy and radiotherapy, can further invade the surrounding brain parenchyma.
View Article and Find Full Text PDFThe importance of conformational rigidity on macroscopic rheological properties was revealed using two model polysaccharides, namely, xanthan gum and hyaluronic acid. Xanthan gum has a rigid tertiary conformation due to its ordered double-helical structure, and the interactions between the tertiary structures result in the formation of a network/quaternary structure. In comparison, hyaluronic acid possesses a relatively flexible tertiary conformation due to its secondary random coil structure.
View Article and Find Full Text PDFBiofilms represent the dominant microbial lifestyle in nature. These complex microbial communities in which bacteria are embedded in a self-produced protective polymeric extracellular matrix, display an enhanced resistance to antimicrobials and thus represent a major health challenge. Although nanoparticles have proven to be effective against bacteria, the interactions between nanoparticles and the polymeric biofilm matrix are still unclear.
View Article and Find Full Text PDFTo overcome the radioresistance of glioblastoma (GBM) cells infiltrated in the brain, we propose to attract these cancer cells into a trap to which a lethal radiation dose can be delivered safely. Herein, we have prepared and characterized a sodium alginate-based macroporous hydrogel as a potential cancer cell trap. Microcomputed X-ray tomography shows that the hydrogel matrices comprise interconnected pores with an average diameter of 300 μm.
View Article and Find Full Text PDFThe authors wish to make the following correction to this paper [...
View Article and Find Full Text PDFIn this article, a dual-solvent method is presented which allows for precise control over the distribution of nanoparticles (NPs) in hydrogels. The technique is based on the interfacial reaction between a reducing agent (herein THPC) initially solubilized in the hydrogel phase, and an organometallic precursor (herein Au(PPh)Cl) solubilized in the surrounding organic liquid phase. When the organic phase is completely immiscible with water, the interfacial reaction yields a fragile monolayer film of NPs at the hydrogel surface.
View Article and Find Full Text PDFChitosan (Chit) currently used to prepare nanoparticles (NPs) for brain application can be complexed with negatively charged polymers such as alginate (Alg) to better entrap positively charged molecules such as CXCL12. A sustained CXCL12 gradient created by a delivery system can be used, as a therapeutic approach, to control the migration of cancerous cells infiltrated in peri-tumoral tissues similar to those of glioblastoma multiforme (GBM). For this purpose, we prepared Alg/Chit NPs entrapping CXCL12 and characterized them.
View Article and Find Full Text PDFBiofilm is the dominant microbial form found in nature, in which bacterial species are embedded in a self-produced extracellular matrix (ECM). These complex microbial communities are responsible for several infections when they involve multispecies pathogenic bacteria. In previous studies, interfacial rheology proved to be a unique quantitative technique to follow in real-time the biofilm formation at the air-liquid interface.
View Article and Find Full Text PDFJ Colloid Interface Sci
February 2020
Hypothesis: Solid-stabilized Pickering emulsions have attracted a lot of attention recently due to their surfactant-free character, and exceptional stability. At the moment, how the viscosities of the liquid phases impact the processing of Pickering emulsions remain to be clearly understood - it is however an important parameter to consider when developing chemical engineering processes employing these multiphase liquids. Our first assumption was that the amount of emulsified dispersed phase would drastically decrease as viscosity increases.
View Article and Find Full Text PDFIn natural habitats, bacterial species often coexist in biofilms. They interact in synergetic or antagonistic ways and their interactions can influence the biofilm development and properties. Still, very little is known about how the coexistence of multiple organisms impact the multispecies biofilm properties.
View Article and Find Full Text PDFACS Appl Mater Interfaces
June 2018
This work demonstrates that a model system of poly( N-isopropylacrylamide) (PNIPAam) macroporous hydrogels, with tailored microstructures and comprising gold (Au) or silver (Ag) nanoparticles, display enhanced and tunable catalytic activity. These nanocomposites are prepared using polymer templates obtained from melt-processed cocontinuous polymer blends. The reaction rate, controlled by both hydrogel porosity and the PNIPAam lower critical solution temperature, increases by more than an order of magnitude as compared to nonporous gels, and is comparable to micro- or nanocarrier-based systems, with easier catalyst recovery.
View Article and Find Full Text PDFIn this article, we demonstrate that submicrometer particles with surface-grafted sodium alginate (SA) display enhanced and reversible aggregation/disaggregation properties in aqueous solution. 300 nm silica particles were first functionalized with an aminosilane coupling agent, followed by the grafting of pH-sensitive SA, as confirmed by zeta potential, XPS and FTIR analyses. The SA-modified particles show enhanced aggregation properties at acidic pH compared to unmodified silica, with a 10 times increase in average aggregate diameter.
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