Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Bursting of sensitive polymersomes induced by curling.

ABSTRACT: Polymersomes, which are stable and robust vesicles made of block copolymer amphiphiles, are good candidates for drug carriers or micro/nanoreactors. Polymer chemistry enables almost unlimited molecular design of responsive polymersomes whose degradation upon environmental changes has been used for the slow release of active species. Here, we propose a strategy to remotely trigger instantaneous polymersome bursting. We have designed asymmetric polymer vesicles, in which only one leaflet is composed of responsive polymers. In particular, this approach has been successfully achieved by using a UV-sensitive liquid-crystalline copolymer. We study experimentally and theoretically this bursting mechanism and show that it results from a spontaneous curvature of the membrane induced by the remote stimulus. The versatility of this mechanism should broaden the range of applications of polymersomes in fields such as drug delivery, cosmetics and material chemistry.

SUBMITTER: Mabrouk E

PROVIDER: S-EPMC2678645 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Bursting of sensitive polymersomes induced by curling.

Mabrouk Elyes E Cuvelier Damien D Brochard-Wyart Françoise F Nassoy Pierre P Li Min-Hui MH

Proceedings of the National Academy of Sciences of the United States of America 20090421 18

Polymersomes, which are stable and robust vesicles made of block copolymer amphiphiles, are good candidates for drug carriers or micro/nanoreactors. Polymer chemistry enables almost unlimited molecular design of responsive polymersomes whose degradation upon environmental changes has been used for the slow release of active species. Here, we propose a strategy to remotely trigger instantaneous polymersome bursting. We have designed asymmetric polymer vesicles, in which only one leaflet is compos ...[more]

PMID: 19383800

Similar Datasets

Expansile crosslinked polymersomes for pH sensitive delivery of doxorubicin.

Project description:We report a new crosslinked polymersome with pH-responsive swelling properties through acidic hydrolysis of hydrophobic contents from the amphiphilic polymer chains. Its unique stability under physiological conditions and large swelling capability under low pH conditions give this polymersome promising potential for anticancer drug delivery.

| S-EPMC4758355 | biostudies-literature

Targeting Estrogen Receptor-Positive Breast Microtumors with Endoxifen-Conjugated, Hypoxia-Sensitive Polymersomes.

Project description:Endoxifen is the primary active metabolite of tamoxifen, a nonsteroidal-selective estrogen receptor modulator (SERM) and widely used medication to treat estrogen receptor-positive (ER+) breast cancer. In this study, endoxifen was conjugated to the surface of polymeric nanoparticles (polymersomes) for targeted delivery of doxorubicin (DOX) to estrogen receptor-positive breast cancer cells (MCF7). Rapid cell growth and insufficient blood supply result in low oxygen concentration (hypoxia) within the solid breast tumors. The polymersomes developed here are prepared from amphiphilic copolymers of polylactic acid (PLA) and poly(ethylene glycol) (PEG) containing diazobenzene as the hypoxia-responsive linker. We prepared two nanoparticle formulations: DOX-encapsulated hypoxia-responsive polymersomes (DOX-HRPs) and endoxifen-conjugated, DOX-encapsulated hypoxia-responsive polymersomes (END-DOX-HRPs). Cellular internalization studies demonstrated eight times higher cytosolic and nuclear localization after incubating breast cancer cells with END-DOX-HRPs (targeted polymersomes) in contrast to DOX-HRPs (nontargeted polymersomes). Cytotoxicity studies on monolayer cell cultures exhibited that END-DOX-HRPs were three times more toxic to ER+ MCF7 cells than DOX-HRPs and free DOX in hypoxia. The cell viability studies on three-dimensional hypoxic cultures also demonstrated twice as much toxicity when the spheroids were treated with targeted polymersomes instead of nontargeted counterparts. This is the first report of surface-decorated polymeric nanoparticles with endoxifen ligands for targeted drug delivery to ER+ breast cancer microtumors. The newly designed endoxifen-conjugated, hypoxia-responsive polymersomes might have translational potential for ER+ breast cancer treatment.

| S-EPMC8552235 | biostudies-literature

Geometry-induced bursting dynamics in gene expression.

Project description:In prokaryotes and eukaryotes, genes are transcribed stochastically according to various temporal patterns that range from simple first-order kinetics to marked bursts, resulting in temporal and cell-to-cell variations of mRNA and protein levels. Here, we consider the effect of the transport of regulatory molecules on the noise in gene expression by taking into account explicitly the dynamics of a finite number of transcription factors confined in the cell. We calculate analytically time-dependent correlation functions of mRNA levels for a wide range of transport mechanisms and find that in the limit of small-transcription-factor copy number, the results differ significantly from standard approaches, which ignore confinement. It is shown how such dynamical quantities, which can now be obtained experimentally, can be used to identify the underlying mechanisms of transcription. Of particular importance, it is demonstrated that the geometry of transcription-factor trajectories in the cellular environment plays a key role in transcription kinetics, and can intrinsically generate the observed various transcription patterns ranging from simple first-order kinetics to bursts.

| S-EPMC3341560 | biostudies-literature

Peptide-Induced Division of Polymersomes for Biomimetic Compartmentalization.

Project description:Polymersomes are synthetic vesicles that mimic the architecture of cellular compartments such as the cell membrane and organelles. These biomimetic compartments facilitate the creation of cell-like chemical systems, including microreactors and synthetic organelles. However, the construction of hierarchical multi-compartment systems remains challenging and typically requires the encapsulation of pre-formed vesicles within a host compartment. Here, we report the formation of multicompartment polymersomes with a vesicle-in-vesicle architecture achieved through self-division induced by short peptides incorporated into the vesicle membrane. A phenylalanine-phenylalanine-methionine (FFM) tripeptide was designed and encapsulated into the polymersome via microfluidics. We demonstrate that vesicle self-division occurs due to peptide incorporation into the membrane in response to pH changes. This self-division creates internal vesicles capable of colocalizing enzymes. The hybrid polymer-peptide system described here provides a straightforward method for developing subcompartmentalized systems, paving the way for engineering microreactors with life-like properties.

| S-EPMC11656130 | biostudies-literature

Scale-free bursting activity in shrinkage induced cracking.

Project description:Based on computer simulations of a realistic discrete element model we demonstrate that shrinkage induced cracking of thin layers of heterogeneous materials, generating spectacular crack patterns, proceeds in bursts. These crackling pulses are characterized by scale free distributions of size and duration, however, with non-universal exponents depending on the system size and shrinking rate. On the contrary, local avalanches composed of micro-cracking events with temporal and spatial correlation are found to obey a universal power law statistics. Most notably, we demonstrate that the observed non-universality of the integrated signal is the consequence of the temporal superposition of the underlying local avalanches, which pop up in an uncorrelated way in homogeneous systems. Our results provide an explanation of recent acoustic emission measurements on drying induced shrinkage cracking and may have relevance for the acoustic monitoring of the electro-mechanical degradation of battery electrodes.

| S-EPMC10965922 | biostudies-literature

Study of curling mechanism by precision kinematic measurements of curling stone's motion.

Project description:Why do curling stones curl? That is a question physicists are often asked, yet no answer has been established. Stones rotating clockwise curl right, contrary to our naive expectations. After a century of debate between contradicting hypotheses, this paper provides a possible answer based on experimental evidence. A digital image analysis technique was used to perform precision kinematic measurements of a curling stone's motion to identify the curling mechanism. We observed a significant left-right asymmetric friction due to velocity dependence on the friction coefficient. Combined with the discrete point-like nature of the friction between ice and stone, swinging around slow-side friction points has been concluded as the dominant origin of the curling. Many new angular momentum transfer phenomena have been found, supporting this conclusion.

| S-EPMC9440934 | biostudies-literature

Tuneable Time Delay in the Burst Release from Oxidation-Sensitive Polymersomes Made by PISA.

Project description:Reactive polymersomes represent a versatile artificial cargo carrier system that can facilitate an immediate release in response to a specific stimulus. The herein presented oxidation-sensitive polymersomes feature a time-delayed release mechanism in an oxidative environment, which can be precisely adjusted by either tuning the membrane thickness or partial pre-oxidation. These polymeric vesicles are conveniently prepared by PISA allowing the straightforward and effective in situ encapsulation of cargo molecules, as shown for dyes and enzymes. Kinetic studies revealed a critical degree of oxidation causing the destabilization of the membrane, while no release of the cargo is observed beforehand. The encapsulation of glucose oxidase directly transforms these polymersomes into glucose-sensitive vesicles, as small molecules including sugars can passively penetrate their membrane. Considering the ease of preparation, these polymersomes represent a versatile platform for the confinement and burst release of cargo molecules after a precisely adjustable time span in the presence of specific triggers, such as H2 O2 or glucose.

| S-EPMC8596869 | biostudies-literature

Spontaneous and information-induced bursting activities in honeybee hives.

Project description:Social entrainment is important for functioning of beehive organization. By analyzing a dataset of approximately 1000 honeybees (Apis mellifera) tracked in 5 trials, we discovered that honeybees exhibit synchronized activity (bursting behavior) in their locomotion. These bursts occurred spontaneously, potentially as a result of intrinsic bee interactions. The empirical data and simulations demonstrate that physical contact is one of the mechanisms for these bursts. We found that a subset of honeybees within a hive which become active before the peak of each burst, and we refer to these bees as "pioneer bees." Pioneer bees are not selected randomly, but rather, are linked to foraging behavior and waggle dancing, which may help spread external information in the hive. By using transfer entropy, we found that information flows from pioneer bees to non-pioneer bees, which suggest that the bursting behavior is caused by foraging behavior and spreading the information through the hive and promoting integrated group behavior among individuals.

| S-EPMC10329038 | biostudies-literature

Chemical memory reactions induced bursting dynamics in gene expression.

Project description:Memory is a ubiquitous phenomenon in biological systems in which the present system state is not entirely determined by the current conditions but also depends on the time evolutionary path of the system. Specifically, many memorial phenomena are characterized by chemical memory reactions that may fire under particular system conditions. These conditional chemical reactions contradict to the extant stochastic approaches for modeling chemical kinetics and have increasingly posed significant challenges to mathematical modeling and computer simulation. To tackle the challenge, I proposed a novel theory consisting of the memory chemical master equations and memory stochastic simulation algorithm. A stochastic model for single-gene expression was proposed to illustrate the key function of memory reactions in inducing bursting dynamics of gene expression that has been observed in experiments recently. The importance of memory reactions has been further validated by the stochastic model of the p53-MDM2 core module. Simulations showed that memory reactions is a major mechanism for realizing both sustained oscillations of p53 protein numbers in single cells and damped oscillations over a population of cells. These successful applications of the memory modeling framework suggested that this innovative theory is an effective and powerful tool to study memory process and conditional chemical reactions in a wide range of complex biological systems.

| S-EPMC3549921 | biostudies-literature

LRP1-mediated pH-sensitive polymersomes facilitate combination therapy of glioblastoma in vitro and in vivo.

Project description:BackgroundGlioblastoma (GBM) is the most invasive primary intracranial tumor, and its effective treatment is one of the most daunting challenges in oncology. The blood-brain barrier (BBB) is the main obstacle that prevents the delivery of potentially active therapeutic compounds. In this study, a new type of pH-sensitive polymersomes has been designed for glioblastoma therapy to achieve a combination of radiotherapy and chemotherapy for U87-MG human glioblastoma xenografts in nude mice and significantly increased survival time.ResultsThe Au-DOX@PO-ANG has a good ability to cross the blood-brain barrier and target tumors. This delivery system has pH-sensitivity and the ability to respond to the tumor microenvironment. Gold nanoparticles and doxorubicin are designed as a complex drug. This type of complex drug improve the radiotherapy (RT) effect of glioblastoma. The mice treated with Au-DOX@PO-ANG NPs have a significant reduction in tumor volume.ConclusionIn summary, a new pH-sensitive drug delivery system was fabricated for the treatment of glioblastoma. The new BBB-traversing drug delivery system potentially represents a novel approach to improve the effects of the treatment of intracranial tumors and provides hope for glioblastoma treatment.

| S-EPMC7821499 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

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