PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 10415563

New multicomponent capsules for immunoisolation.

A Bartkowiak·L Canaple·I Ceausoglu·N Nurdin·A Renken·L Rindisbacher·C Wandrey·B Desvergne·D Hunkeler
View original source ↗Export metadata ↓

Abstract

A new generation of microcapsules based on the use of oligomers which participate in polyelectrolyte complexation reactions has been developed. These freeze-thaw stable capsules have been applied as a bioartificial pancreas and have resulted in normoglycemia for periods of six months in concordant xenotransplantations. The new chemistry permits the control of permeability and mechanical properties over a wide range and can be adapted both to microcapsule and hollow fiber geometries rendering it a robust tool for encapsulation in general. Methods, and metrics, for the characterization of the mechanical properties and permeability of microcapsules are presented.

Explore related subjects

Artificial OrgansCapsulesIslets of Langerhans TransplantationMaterials TestingPermeabilityTransplantation, HeterologousJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

A Bartkowiak, L Canaple, I Ceausoglu, N Nurdin, A Renken, L Rindisbacher, C Wandrey, B Desvergne, D Hunkeler. 1999-06-18. New multicomponent capsules for immunoisolation.. https://doi.org/10.1111/j.1749-6632.1999.tb08499.x

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2006

Artificial muscles based on liquid crystal elastomers.

This paper presents our results on liquid crystal (LC) elastomers as artificial muscle, based on the ideas proposed by de Gennes. In the theoretical model, the material consists of a repeated series of main-chain nematic LC polymer blocks, N, and conventional rubber blocks, R, based on the lamellar phase of a triblock copolymer RNR. The motor for the contraction is the reversible macromolecular shape change of the chain, from stretched to spherical, that occurs at the nematic-to-isotropic phase transition in the main-chain nematic LC polymers. We first developed a new kind of muscle-like material based on a network of side-on nematic LC homopolymers. Side-on LC polymers were used instead of main-chain LC polymers for synthetic reasons. The first example of these materials was thermo-responsive, with a typical contraction of around 35-45% and a generated force of around 210 kPa. Subsequently, a photo-responsive material was developed, with a fast photochemically induced contraction of around 20%, triggered by UV light. We then succeeded in preparing a thermo-responsive artificial muscle, RNR, with lamellar structure, using a side-on nematic LC polymer as N block.Micrometre-sized artificial muscles were also prepared. This paper illustrates the bottom-up design of stimuli-responsive materials, in which the overall material response reflects the individual macromolecular response, using LC polymer as building block.

Artificial Organs↗
PubMed2006

A design framework to model retinas.

Neuro-engineering is providing biomedical engineers with technology to interface the nervous system, which is useful to create prosthetic devices to palliate sensorial or motor disabilities. Motivated by the success of cochlear implants for deaf patients, we are now facing the challenge of creating a prosthetic visual system for the blind. An artificial retina whose response to stimuli can be matched to biological ones is required. To make easier the task of modeling, tuning and testing these retinal models, we have created a software tool that allows flexible and parametric definition and testing of retina-like models. The program can be fed with a variety of video or image sources, and the results can be easily compared to biological recordings of retinal ganglionar activity in response to the same stimuli. This tool can be useful, not only for this prosthetic purpose, but for any other research involving bio-inspired image processing with a neuromorphic output.

Artificial Organs↗