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
2009 ◽  
Vol 1190 ◽  
Author(s):  
Christian Wischke ◽  
Axel Thomas Neffe ◽  
Susi Steuer ◽  
Andreas Lendlein

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.


2021 ◽  
Vol 12 (2) ◽  
pp. 1037-1043
Author(s):  
Madhusudana T. ◽  
Mamatha G. P. ◽  
Demappa T. ◽  
Satyanarayan N. D.

Hydrogels are 3D polymer networks capable to absorb and release water or biological fluids. They are stimuli-responsive materials, which can show rapid volume changes with response to small changes in environmental parameters such as ionic strength, pH, and temperature. In this work, we performed a synthesis of Poly(acrylamide) hydrogel and tested for controlled release of levofloxacin hemihydrate as a model drug. We used sodium metabisulfite and potassium persulphate as free radical initiators to prepare hydrogel with methylenebisacrylamide as a crosslinker. Characterization of hydrogel was performed by TGA, SEM, and FT-IR. Swelling study and drug release were performed at pH 1.2 and 7.4 solutions, identical to the gastrointestinal fluid at 37°C (human body temperature) to examine possible site-specific drug delivery. UV-Visible spectrophotometer was used to measure the concentration of drug release. Results exhibited the pH and temperature-dependent drug release. The amount of drug release was found to be 17% and 99% in acidic and alkaline pH of 1.2 and 7.4, respectively, after 6 hours.


2009 ◽  
Vol 21 (32-33) ◽  
pp. 3394-3398 ◽  
Author(s):  
Axel T. Neffe ◽  
Bui D. Hanh ◽  
Susi Steuer ◽  
Andreas Lendlein

2018 ◽  
Vol 68 (12) ◽  
pp. 2925-2918
Author(s):  
Gabriela Cioca ◽  
Maricel Agop ◽  
Marcel Popa ◽  
Simona Bungau ◽  
Irina Butuc

One of the main challenges in designing a release system is the possibility to control the release rate in order to maintain it at a constant value below a defined limit, to avoid exceeding the toxicity threshold. We propose a method of overcoming this difficulty by introducing the drug into liposomes, prior to its inclusion in the hydrogel. Furthermore, a natural cross linker (as is tannic acid) is used, instead of the toxic cross linkers commonly used, thus reducing the toxicity of the release system as a whole.


2018 ◽  
Vol 14 (5) ◽  
pp. 432-439 ◽  
Author(s):  
Juliana M. Juarez ◽  
Jorgelina Cussa ◽  
Marcos B. Gomez Costa ◽  
Oscar A. Anunziata

Background: Controlled drug delivery systems can maintain the concentration of drugs in the exact sites of the body within the optimum range and below the toxicity threshold, improving therapeutic efficacy and reducing toxicity. Mesostructured Cellular Foam (MCF) material is a new promising host for drug delivery systems due to high biocompatibility, in vivo biodegradability and low toxicity. Methods: Ketorolac-Tromethamine/MCF composite was synthesized. The material synthesis and loading of ketorolac-tromethamine into MCF pores were successful as shown by XRD, FTIR, TGA, TEM and textural analyses. Results: We obtained promising results for controlled drug release using the novel MCF material. The application of these materials in KETO release is innovative, achieving an initial high release rate and then maintaining a constant rate at high times. This allows keeping drug concentration within the range of therapeutic efficacy, being highly applicable for the treatment of diseases that need a rapid response. The release of KETO/MCF was compared with other containers of KETO (KETO/SBA-15) and commercial tablets. Conclusion: The best model to fit experimental data was Ritger-Peppas equation. Other models used in this work could not properly explain the controlled drug release of this material. The predominant release of KETO from MCF was non-Fickian diffusion.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Joseph C. Bear ◽  
P. Stephen Patrick ◽  
Alfred Casson ◽  
Paul Southern ◽  
Fang-Yu Lin ◽  
...  

Author(s):  
Suyoung Been ◽  
Jeongmin Choi ◽  
Young Hun Lee ◽  
Pil Yun Kim ◽  
Won Kyung Kim ◽  
...  

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