Browse
Submit Data
Databases
API
Help

Dataset Information

23 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Multifunctional shape and size specific magneto-polymer composite particles.

ABSTRACT: Interest in uniform multifunctional magnetic particles is driven by potential applications in biomedical and materials science. Here we demonstrate the fabrication of highly tailored nanoscale and microscale magneto-polymer composite particles using a template based approach. Regiospecific surface functionalization of the particles was performed by chemical grafting and evaporative Pt deposition. Manipulation of the particles by an applied magnetic field was demonstrated in water and hydrogen peroxide.

SUBMITTER: Nunes J

PROVIDER: S-EPMC3357060 | biostudies-literature | 2010 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Multifunctional shape and size specific magneto-polymer composite particles.

Nunes Janine J Herlihy Kevin P KP Mair Lamar L Superfine Richard R DeSimone Joseph M JM

Nano letters 20100401 4

Interest in uniform multifunctional magnetic particles is driven by potential applications in biomedical and materials science. Here we demonstrate the fabrication of highly tailored nanoscale and microscale magneto-polymer composite particles using a template based approach. Regiospecific surface functionalization of the particles was performed by chemical grafting and evaporative Pt deposition. Manipulation of the particles by an applied magnetic field was demonstrated in water and hydrogen pe ...[more]

PMID: 20334397

Similar Datasets

Shape induced inhibition of phagocytosis of polymer particles.

Project description:To determine if particle shape can be engineered to inhibit phagocytosis of drug delivery particles by macrophages, which can be a significant barrier to successful therapeutic delivery.Non-spherical polystyrene particles were fabricated by stretching spherical particles embedded in a polymer film. A rat alveolar macrophage cell line was used as model macrophages. Phagocytosis of particles was assessed using time-lapse video microscopy and fluorescence microscopy.We fabricated worm-like particles with very high aspect ratios (>20). This shape exhibits negligible phagocytosis compared to conventional spherical particles of equal volume. Reduced phagocytosis is a result of decreasing high curvature regions of the particle to two single points, the ends of the worm-like particles. Internalization is possible only at these points, while attachment anywhere along the length of the particles inhibits internalization due to the low curvature.Shape-induced inhibition of phagocytosis of drug delivery particles is possible by minimizing the size-normalized curvature of particles. We have created a high aspect ratio shape that exhibits negligible uptake by macrophages.

| S-EPMC2810499 | biostudies-literature

A facile synthesis of dynamic, shape-changing polymer particles.

Project description:We herein report a new facile strategy to ellipsoidal block copolymer nanoparticles that exhibit a pH-triggered anistropic swelling profile. In a first step, elongated particles with an axially stacked lamellae structure are selectively prepared by utilizing functional surfactants to control the phase separation of symmetric polystyrene-b-poly(2-vinylpyridine) (PS-b-P2VP) in dispersed droplets. In a second step, the dynamic shape change is realized by cross-linking the P2VP domains, thereby connecting glassy PS discs with pH-sensitive hydrogel actuators.

| S-EPMC4074252 | biostudies-literature

Polymer particles that switch shape in response to a stimulus.

Project description:Particle engineering for biomedical applications has unfolded the roles of attributes such as size, surface chemistry, and shape for modulating particle interactions with cells. Recently, dynamic manipulation of such key properties has gained attention in view of the need to precisely control particle interaction with cells. With increasing recognition of the pivotal role of particle shape in determining their biomedical applications, we report on polymeric particles that are able to switch their shape in real time in a stimulus-responsive manner. The shape-switching behavior was driven by a subtle balance between polymer viscosity and interfacial tension. The balance between the two forces was modulated by application of an external stimulus chosen from temperature, pH, or chemical additives. The dynamics of shape switch was precisely controlled over minutes to days under physiological conditions. Shape-switching particles exhibited unique interactions with cells. Elliptical disk-shaped particles that are not phagocytosed by macrophages were made to internalize through shape switch, demonstrating the ability of shape-switchable particles in modulating interaction with cells.

| S-EPMC2895097 | biostudies-literature

Size-Dependent Photophysical Behavior of Low Bandgap Semiconducting Polymer Particles.

Project description:The photophysics of water and propan-1-ol suspensions of poly [N-9"-heptadecanyl-2,7-carbazole-alt-5,5-(4,7-di-2-thienyl-2',1',3'- benzothiadiazole)] (PCDTBT) nanoparticles and mesoparticles has been studied by ultrafast spectroscopy. High molar mass polymer (HMM > 20 kg/mol) forms nanoparticles with around 50 nm diameter via mini-emulsion post-polymerization, while low molar mass (LMM < 5 kg/mol) polymer prepared by dispersion polymerization results in particles with a diameter of almost one order of magnitude larger (450 ± 50 nm). In this study, the presence of excited-states and charge separated species was identified through UV pump and visible/near-infrared probe femtosecond transient absorption spectroscopy. A different behavior for the HMM nanoparticles has been identified compared to the LMM mesoparticles. The nanoparticles exhibit typical features of an energetically disordered conjugated polymer with a broad density of states, allowing for delayed spectral relaxation of excited states, while the mesoparticles show a J-aggregate-like behavior where interchain interactions are less efficient. Stimulated emission in the red-near infrared region has been found in the mesoparticles which indicates that they present a more energetically ordered system.

| S-EPMC6584897 | biostudies-literature

Minimizing the hydrodynamic size of quantum dots with multifunctional multidentate polymer ligands.

Project description:We report a new strategy to minimize the hydrodynamic size of quantum dots (QDs) and to overcome their colloidal stability and photobleaching problems based on the use of multifunctional and multidentate polymer ligands. A novel finding is that a balanced composition of thiol (-SH) and amine (-NH 2) coordinating groups grafted to a linear polymer chain leads to highly compact nanocrystals with exceptional colloidal stability, a strong resistance to photobleaching, and high fluorescence quantum yields. In contrast to the standing brushlike conformation of PEGylated dihydrolipoic acid molecules, mutlidentate polymer ligands can wrap around the QDs in a closed "loops-and-trains" conformation. This structure is highly stable thermodynamically and is responsible for the excellent colloidal and optical properties. We have optimized this process for the preparation of ultrastable CdTe nanocrystals and have found the strategy to be broadly applicable to a wide range of nanocrystalline materials and heterostructures. This work has led to a new generation of bright and stable QDs with small hydrodynamic diameters between 5.6 and 9.7 nm with tunable fluorescence emission from the visible (515 nm) to the near-infrared (720 nm). These QDs are well suited for molecular and cellular imaging applications in which the nanoparticle hydrodynamic size must be minimized.

| S-EPMC2703485 | biostudies-literature

Photothermal-Triggered Shape Memory Polymer Prepared by Cross-Linking Porphyrin-Loaded Micellar Particles.

Project description:In this work, we fabricated porphyrin-loaded shape memory polymer (SMP) film by cross-linking micellar particles prepared by co-assembly of porphyrin compounds and amphiphilic macromolecules formulated by copolymerization of 2-butoxy ethanol (BCS), methyl methacrylate (MMA), butyl acrylate (BA) acrylic acid (AA), and diacetone acrylamide (DAAM). The experimental results revealed that this film was able to respond to the red light in terms of photothermal effect enabled by the porphyrin filler. The photothermal-triggered shape memory behaviors of the film were further examined in detail. It was noteworthy that this material was expected to have potential applications in the biomedical field due to the excellent biocompatibility of the porphyrin filler and the red-light source, which was optimal and safe enough for biomedical treatment.

| S-EPMC6384967 | biostudies-literature

The shape and size of hydroxyapatite particles dictate inflammatory responses following implantation.

Project description:The extent of regeneration following biomaterial implantation is dependent on the microenvironment surrounding the implant. Since implant composition can have a profound effect on inflammation, it is essential to understand this process as a non-resolving inflammatory response can lead to fibrous encapsulation and insufficient integration. Incorporation of particulates into implants confers structural and functional benefits, thus optimizing particulate characteristics to enhance immune mediated efficacy is important. We investigated the relationship between the nature of hydroxyapatite (HA) particles and the innate immune response, focusing on how particle size (0.1?µm, 5?µm, 20?µm, 100?µm) and morphology (needle-shaped/spherical; smooth/rough surface) modulates inflammatory responses. We observed a shape and size-dependent activation of the NLRP3 inflammasome and IL-1? secretion; while needle-shaped and smaller HA particles significantly enhanced cytokine secretion, larger particles did not. Moreover, HA particle characteristics profoundly influenced patterns of innate immune cell recruitment and cytokine production following injection. While small, needle-shaped particles induced a strong inflammatory response, this was not observed with smooth, spherical particles of comparable size or with larger particles. These findings indicate that hydroxyapatite particle characteristics dictate immune cell recruitment and the ensuing inflammatory response, providing an opportunity to tailor HA particle characteristics to regulate immune responses induced after biomaterial implantation.

| S-EPMC5462791 | biostudies-literature

Size-Dependent Photodynamic Anticancer Activity of Biocompatible Multifunctional Magnetic Submicron Particles in Prostate Cancer Cells.

Project description:In this study, newly designed biocompatible multifunctional magnetic submicron particles (CoFe?O?-HPs-FAs) of well-defined sizes (60, 133, 245, and 335 nm) were fabricated for application as a photosensitizer delivery agent for photodynamic therapy in cancer cells. To provide selective targeting of cancer cells and destruction of cancer cell functionality, basic cobalt ferrite (CoFe?O?) particles were covalently bonded with a photosensitizer (PS), which comprises hematoporphyrin (HP), and folic acid (FA) molecules. The magnetic properties of the CoFe?O? particles were finely adjusted by controlling the size of the primary CoFe?O? nanograins, and secondary superstructured composite particles were formed by aggregation of the nanograins. The prepared CoFe?O?-HP-FA exhibited high water solubility, good MR-imaging capacity, and biocompatibility without any in vitro cytotoxicity. In particular, our CoFe?O?-HP-FA exhibited remarkable photodynamic anticancer efficiency via induction of apoptotic death in PC-3 prostate cancer cells in a particle size- and concentration-dependent manner. This size-dependent effect was determined by the specific surface area of the particles because the number of HP molecules increased with decreasing size and increasing surface area. These results indicate that our CoFe?O?-HP-FA may be applicable for photodynamic therapy (PDT) as a PS delivery material and a therapeutic agent for MR-imaging based PDT owing to their high saturation value for magnetization and superparamagnetism.

| S-EPMC6273714 | biostudies-literature

Magnetic field-induced rubber-like behavior in Ni-Mn-Ga particles/polymer composite.

Project description:Single crystalline Ni-Mn-Ga is well known as a prototype ferromagnetic shape memory alloy (FSMA) exhibiting a giant magnetic field-induced strain (MFIS), up to 12%, due to the magnetically driven twin boundary rearrangement. The large stroke and fast magnetomechanical response make it important for actuators and sensors. Polycrystalline Ni-Mn-Ga is inexpensive and technologically easy accessible, but constrains from the grain boundaries inhibit the twin boundary motion, whereby a very low MFIS is observed. Here, we have shown for the first time that a polycrystalline Ni-Mn-Ga can be split into the magnetostrain-active single grains which, being specially assembled in a silicone polymer matrix, caused large and fully reversible MFIS of the resulting composite. We termed the unique reversibility of a large MFIS of the composite as the magnetic field-induced rubber-like behavior. The magnetostrain of individual particles was explored by the X-ray μCT 3D imaging. The results suggest novel solutions for development of the low cost magnetic actuators and sensors for haptic applications.

| S-EPMC6401090 | biostudies-other

Nanoscale Design of Nano-Sized Particles in Shape-Memory Polymer Nanocomposites Driven by Electricity.

Project description:In the last few years, we have witnessed significant progress in developing high performance shape memory polymer (SMP) nanocomposites, in particular, for shape recovery activated by indirect heating in the presence of electricity, magnetism, light, radio frequency, microwave and radiation, etc. In this paper, we critically review recent findings in Joule heating of SMP nanocomposites incorporated with nanosized conductive electromagnetic particles by means of nanoscale control via applying an electro- and/or magnetic field. A few different nanoscale design principles to form one-/two-/three- dimensional conductive networks are discussed.

| S-EPMC5452653 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data