Search results for "Biomaterial"
showing 10 items of 1350 documents
From Defined Reactive Diblock Copolymers to Functional HPMA-Based Self-Assembled Nanoaggregates
2008
This paper describes the synthesis of functional amphiphilic poly( N-(2-hydroxypropyl) methacrylamide)-block-poly(lauryl methacrylate) copolymers by RAFT polymerization via the intermediate step of activated ester block copolymers (pentafluoro-phenyl methacrylate). Block copolymers with molecular weights from 12000-28000 g/mol and PDIs of about 1.2 have been obtained. The amphiphilic diblock copolymers form stable super structures (nanoaggregates) by self-organization in aqueous solution. The diameters of these particles are between 100 and 200 nm and depend directly on the molecular weight of the block copolymer. Furthermore, we investigated the impact of these nanoaggregates on cell viabi…
Synthesis and Characterization of Stimuli-Responsive Star-Like Polypept(o)ides: Introducing Biodegradable PeptoStars
2017
tar-like polymers are one of the smallest systems in the class of core crosslinked polymeric nanoparticles. This article reports on a versatile, straightforward synthesis of three-arm star-like polypept(o)ide (polysarcosine-block-polylysine) polymers, which are designed to be either stable or degradable at elevated levels of glutathione. Polypept(o)ides are a recently introduced class of polymers combining the stealth-like properties of the polypeptoid polysarcosine with the functionality of polypeptides, thus enabling the synthesis of materials completely based on endogenous amino acids. The star-like homo and block copolymers are synthesized by living nucleophilic ring opening polymerizat…
PeptoSomes for Vaccination: Combining Antigen and Adjuvant in Polypept(o)ide-Based Polymersomes.
2017
In this work, the first vaccine is reported based on a PeptoSome, which contains a model antigen (SIINFEKL) and adjuvant (CpG). PeptoSomes are polypept(o)ide-based polymersomes built of a block-copolymer with polysarcosine (PSar) as the hydrophilic block (X n = 111) and poly(benzyl-glutamic acid) (PGlu(OBn)) as the hydrophobic one (X n = 46). The polypept(o)ide is obtained with low dispersity index of 1.32 by controlled ring-opening polymerization. Vesicle formation by dual centrifugation technique allows for loading of vesicles up to 40 mol%. PeptoSomes are characterized by multiangle dynamic light scattering, static light scattering, and cryogenic transmission electron microscopy (cryoTEM…
Optical Gating of Photosensitive Synthetic Ion Channels
2011
4-oxo-4-(pyren-4-ylmethoxy) butanoic acid is used as a photolabile protecting group to show the optical gating of nanofluidic devices based on synthetic ion channels. The inner surface of the channels is decorated with monolayers of photolabile hydrophobic molecules that can be removed by irradiation, which leads to the generation of hydrophilic groups. This process can be exploited in the UV-light-triggered permselective transport of ionic species in aqueous solution through the channels. The optical gating of a single conical nanochannel and multichannel polymeric membranes is characterised experimentally and theoretically by means of current-voltage and selective permeation measurements,…
Site-specific halloysite functionalization by polydopamine: A new synthetic route for potential near infrared-activated delivery system
2022
Abstract Halloysite nanotubes (HNTs) represent a versatile core structure for the design of functional nanosystems of biomedical interest. However, the development of selective methodologies for the site-controlled functionalization of the nanotubes at specific sites is not an easy task. This study aims to accomplish a procedure for the site-selective/specific, “pin-point”, functionalization of HNTs with polydopamine (HNTs@PDA). This goal was achieved, at pH 6.5, by exploiting the basicity of ZnO nanoparticles anchored on the HNTs external surface (HNTs@ZnO) to induce a punctual polydopamine polymerization and coating. The morphology and the chemical composition of the nanomaterial was demo…
Enhanced antifungal efficacy of tebuconazole using gated pH-driven mesoporous nanoparticles
2014
Núria Mas,1–3 Irene Galiana,3 Silvia Hurtado,† Laura Mondragón,1–3 Andrea Bernardos,1–3 Félix Sancenón,1–3 María D Marcos,1–3 Pedro Amorós,4 Nuria Abril-Utrillas,5 Ramón Martínez-Máñez,1–3 José Ramón Murguía1,3 1Centro de Reconocimiento Molecular y Desarrollo Tecnológico (IDM), Centro Mixto Universidad Politécnica de Valencia, Universidad de Valencia, Valencia, Spain; 2Departamento de Química, Universidad Politécnica de Valencia, Valenci…
Designed biodegradable hydrogel structures prepared by stereolithography using poly(ethylene glycol)/poly(D,L-lactide)-based resins
2010
Designed three-dimensional biodegradable poly(ethylene glycol)/poly(D,L-lactide) hydrogel structures were prepared for the first time by stereolithography at high resolutions. A photo-polymerisable aqueous resin comprising PDLLA-PEG-PDLLA-based macromer, visible light photo-initiator, dye and inhibitor in DMSO/water was used to build the structures. Porous and non-porous hydrogels with well-defined architectures and good mechanical properties were prepared. Porous hydrogel structures with a gyroid pore network architecture showed narrow pore size distributions, excellent pore interconnectivity and good mechanical properties. The structures showed good cell seeding characteristics, and human…
Dual-beam confocal light-sheet microscopy via flexible acousto-optic deflector
2019
Confocal detection in digital scanned laser light-sheet fluorescence microscopy (DSLM) has been established as a gold standard method to improve image quality. The selective line detection of a complementary metal-oxide-semiconductor camera (CMOS) working in rolling shutter mode allows the rejection of out-of-focus and scattered light, thus reducing background signal during image formation. Most modern CMOS have two rolling shutters, but usually only a single illuminating beam is used, halving the maximum obtainable frame rate. We report on the capability to recover the full image acquisition rate via dual confocal DSLM by using an acoustooptic deflector. Such a simple solution enables us t…
Tissue response and biomaterial integration: the efficacy of in vitro methods
2002
Implantation involves tissue trauma, which evokes an inflammatory response, coupled to a wound healing reaction, involving angiogenesis, fibroblast activation and matrix remodelling. Until now the type and extent of such reactions to give optimal integration of various biomaterials are practically unknown. Three principal fields of research can yield useful data to understand these phenomena better: studies on explanted biomaterials, animal models and relevant in vitro techniques. This paper will present examples of the latter field and the application of endothelial cell (EC) culture systems to study the effects of important tissue (e.g. pro-inflammatory cytokines, chemokines) and material…
Wavefront holoscopy: application of digital in-line holography for the inspection of engraved marks in progressive addition lenses
2014
Progressive addition lenses (PALs) are engraved with permanent marks at standardized locations in order to guarantee correct centering and alignment throughout the manufacturing and mounting processes. Out of the production line, engraved marks provide useful information about the PAL as well as act as locator marks to re-ink again the removable marks. Even though those marks should be visible by simple visual inspection with the naked eye, engraving marks are often faint and weak, obscured by scratches, and partially occluded and difficult to recognize on tinted or antireflection-coated lenses. Here, we present an extremely simple optical device (named as wavefront holoscope) for visualiza…