Amorphous Polymer Networks Combining Three Functionalities–Shape-memory, Biodegradability, and Drug Release

2009 ◽  
Vol 1190 ◽  
Author(s):  
Christian Wischke ◽  
Axel Thomas Neffe ◽  
Susi Steuer ◽  
Andreas Lendlein
Keyword(s):  
Drug Release ◽  
Shape Memory ◽  
Amorphous Polymer ◽  
Polymer Networks ◽  
Three Dimensional ◽  
Hydrolytic Degradation ◽  
Functional Materials ◽  
Controlled Drug Release ◽  
Diffusion Controlled ◽  
Shape Programming

AbstractShape-memory polymers are of high scientific and technological interest in the biomedical field, e.g., as matrix for self-anchoring implantable devices. In this study, two different star-shaped copolyester tetroles, semi-crystalline oligo[(-caprolactone)-co-glycolide]tetrol (oCG) and amorphous oligo[(rac-lactide)-co-glycolide]tetrol (oLG), were synthesized and subsequently crosslinked by a low molecular weight diisocyanate resulting in copolyester urethane networks (N-CG, N-LG). Both networks could be loaded with model drugs and a diffusion controlled release of the drugs was observed without any effect on the mass loss as measure of hydrolytic degradation. However, the N-CG network’s capability of shape programming was disturbed as the crystallinity of the precursors got lost in the complex three dimensional architecture after crosslinking. By contrast, amorphous N-LG network showed an excellent shape-memory capability with a switching temperature around 36 °C corresponding to their glass transition temperature. This led to triple-functional materials combining biodegradability, shape-memory, and controlled drug release.

Polymer Networks Combining Controlled Drug Release, Biodegradation, and Shape Memory Capability

2009 ◽  
Vol 21 (32-33) ◽  
pp. 3394-3398 ◽  
Author(s):  
Axel T. Neffe ◽  
Bui D. Hanh ◽  
Susi Steuer ◽  
Andreas Lendlein
Keyword(s):  
Drug Release ◽  
Shape Memory ◽  
Polymer Networks ◽  
Controlled Drug Release

Ability to Control the Glass Transition Temperature of Amorphous Shape-Memory Polyesterurethane Networks by Varying Prepolymers in Molecular Mass as well as in Type and Content of Incorporated Comonomers

2009 ◽  
Vol 1190 ◽  
Author(s):  
Joerg Zotzmann ◽  
Steffen Kelch ◽  
Armin Alteheld ◽  
Marc Behl ◽  
Andreas Lendlein
Keyword(s):  
Glass Transition ◽  
Minimally Invasive Surgery ◽  
Shape Memory ◽  
Molecular Mass ◽  
Amorphous Polymer ◽  
Polymer Networks ◽  
Precise Control ◽  
Low Weight ◽  
Switching Temperature ◽  
Selection Of

AbstractThe need of intelligent implant materials for applications in the area of minimally invasive surgery leads to tremendous attention for polymers which combine degradability and shape-memory capability. Application of heat, and thereby exceeding a certain switching temperature Tsw, causes the device to changes its shape. The precise control of Tsw is particularly challenging. It was investigated in how far Tg, that can be used as Tsw, of amorphous polymer networks from star-shaped polyester macrotetrols crosslinked with a low-weight linker can be controlled systematically by incorporation of different comonomers into poly(rac-lactide) prepolymers. The molecular mass of the prepolymers as well as type and content of the comonomers was varied. The Tg could be adjusted by selection of comonomer type and ratio without affecting the advantageous elastic properties of the polymer networks.

AB-polymer Networks with Cooligoester and Poly(n -butyl acrylate) Segments as a Multifunctional Matrix for Controlled Drug Release

2010 ◽  
Vol 10 (9) ◽  
pp. 1063-1072 ◽  
Author(s):  
Christian Wischke ◽  
Axel T. Neffe ◽  
Susi Steuer ◽  
Eva Engelhardt ◽  
Andreas Lendlein
Keyword(s):  
Drug Release ◽  
Butyl Acrylate ◽  
Polymer Networks ◽  
Controlled Drug Release

scholarly journals Fundamentals of the mechanical assembling “bottom-up” of individual nanoobjects and nanodevices for the investgations of the quantum non-local phenomena, nanoelectronics and biomedical diagnostics.

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
V.V. Koledov ◽  
◽  
V.G. Shavrov ◽  
S.V. von Gratovsky ◽  
P.V. Lega ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Carbon Nanomaterials ◽  
Field Effect Transistors ◽  
Spin Injection ◽  
Three Dimensional ◽  
Functional Materials ◽  
Basic Research ◽  
Bottom Up

In this work we give an overview of researches, conducted in the framework of the project RFBR-BRICS, together with groups from Brazil, Russia, India, China and South Africa on the development of new technology nanoassembly «bottom-up» various devices for nanoelectronics, nanosensors, biomedicine and basic research based on the use of new functional materials with phase transitions and new physical effects. The Russian group carried out work on improving the nanomanipulation system based on nanotweezers made of Ti2NiCu alloy with shape memory effect. A new design of the control system is proposed, which reduces the control power of the resistive heater and reduces the uncontrolled drift of the nanotweezers by up to 5 times. In the process of joint technological, design and physical research in the field of nanomanipulation and nanoassembly technology, the following main results were obtained by the participating groups. The Indian group, together with the Russian group, studied the melting processes at the micro-level of dimensions, and showed the possibility of manipulating a drop of molten gallium with the help of electromigration and the formation of contact chains for nanoassembly without the use of lithography. Also, the Russian and Indian groups studied the possibility of individual manipulation of microparticles in the liquid. The Chinese group, together with the Russian one, manufactured and tested a prototype of a spin-injection microwave electromagnetic oscillator for nanosensory applications. The Russian and South African groups produced "bottom-up" nanoassembly of carbon nanomaterials, such as CNT, decorated with magnetic ions and nanodiamonds ring structures, and they were searched for quantum effects such as quantum oscillations of transport properties and superconductivity. The Brazilian, Chinese and Russian groups jointly produced prototypes of nano-bio-sensors based on field-effect transistors made of suspended semiconductor nanowires using the bottom-up nanosembly method. Two original approaches to nanoassembly were used: a variant of the traditional scheme with liquid transportation of nanowires and an approach based on three-dimensional manipulation using the nanotweezers with a shape memory effect.

scholarly journals Three-dimensional Hydrogels of Alginate/chitosan Semi-interpenetrating Polymer Networks and Nanocelluloses

2021 ◽  
Author(s):  
Priscila Siqueira ◽  
Ana de Lima ◽  
Felipe Medeiros ◽  
Augusta Isaac ◽  
Katia Novack ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dimensional Stability ◽  
Cellulose Nanocrystals ◽  
Biomedical Applications ◽  
Cellulose Nanofibers ◽  
Polymer Networks ◽  
Three Dimensional ◽  
Controlled Drug Release ◽  
Interpenetrating Polymer Networks ◽  
Post Treatment

Abstract The hydrogels are advanced materials used in biomedical applications during wound healing, controlled drug release and to prepare scaffolds. In this work are prepared hydrogels of alginate/chitosan (Alg/Ch) semi-interpenetrating polymer networks (semi-IPN’s) and nanocelluloses. The hydrogels after preparation by freeze drying are namely simply as gels. The cellulose nanocrystals (CNC’s) are obtained from acid hydrolysis of bleached Eucalyptus pulps and oxidized cellulose nanocrystals (CNCT’s) prepared by (2,2,6,6-tetramethylpiperidin-1-yl)oxyl radical catalyzed reaction as known as TEMPO reaction. The cellulose nanofibers (NFC’s) are obtained from mechanical shearing of cellulose pulps and oxidized NFC’s by TEMPO-mediated reaction (NFCT’s). The nanocellulose suspension and gels are characterized by FTIR at ATR mode, TGA, XRD, TEM, SEM, X-ray computed microtomography (micro-CT) and DMTA. The addition of CNC’s, NFC’s, CNCT’s or NFCT’s in the microstructure of gels increases their dimensional stabilities. The best results are obtained when CNCT’s and NFCT’s are added. The mechanical properties and dimensional stability of Alg/Ch semi-IPN’s increase after controlled thermal post-treatment. The heating during thermal post-treatment boosts the physicochemical interactions in the microstructures of semi-IPN’s. The biological assays show biocompatibility of fibroblast cells on the substrates, and differentiation and proliferation up seven days. The optimized mechanical properties, dimensional stability and biocompatibility of the gels studied in this work are important parameters for potential biomedical applications of these biomaterials.

Light-responsive arylazopyrazole-based hydrogels: their applications as shape-memory materials, self-healing matrices and controlled drug release systems

2019 ◽  
Vol 10 (30) ◽  
pp. 4106-4115 ◽  
Author(s):  
Gilad Davidson-Rozenfeld ◽  
Lucas Stricker ◽  
Julian Simke ◽  
Michael Fadeev ◽  
Margarita Vázquez-González ◽  
...  
Keyword(s):  
Drug Release ◽  
Nucleic Acids ◽  
Shape Memory ◽  
Carboxymethyl Cellulose ◽  
Controlled Drug Release ◽  
Self Healing ◽  
Stimuli Responsive ◽  
Shape Memory Materials ◽  
Responsive Hydrogels

Carboxymethyl cellulose functionalized with nucleic acids, β-cyclodextrin and arylazopyrazole photoisomerizable units self-assembles into stimuli-responsive hydrogels.

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