Structure evolution during phase separation in spin-coated ethylcellulose/hydroxypropylcellulose films

Soft Matter ◽  
2021 ◽  
Author(s):  
Pierre Carmona ◽  
Magnus Röding ◽  
Aila Särkkä ◽  
Christian von Corswant ◽  
Eva Olsson ◽  
...  
Keyword(s):  
Phase Separation ◽  
Drug Release ◽  
Film Thickness ◽  
Spin Coating ◽  
Good Control ◽  
Controlled Drug Release ◽  
Structure Evolution ◽  
Length Scale ◽  
Method Optimization

Porous phase-separated films made of ethylcellulose (EC) and hydroxypropylcellulose (HPC) for controlled drug release were made using spin-coating. The method optimization gave good control over the film thickness and the length scale.

Lateral and Vertical Phase Separation Control of Thin-film Structures for Photovoltaics

2001 ◽  
Vol 665 ◽  
Author(s):  
A. C. Arias ◽  
J. D. MacKenzie ◽  
N. Corcoran ◽  
R. H. Friend
Keyword(s):  
Phase Separation ◽  
Spin Coating ◽  
Solution Viscosity ◽  
Separation Control ◽  
Nanometer Scale ◽  
Length Scale ◽  
Photovoltaic Devices ◽  
Photovoltaic Properties ◽  
Lateral Phase Separation ◽  
Photoluminescence Efficiency

ABSTRACTInvestigations on microscopic and photovoltaic properties of polyfluorene blends are presented here. The length scale of lateral phase separation is manipulated by control of solvent evaporation conditions. Photoluminescence efficiency measurements show that charge transfer is more effective in blends phase separated on the nanometer scale. Vertically segregated structures are obtained by a combination of solution viscosity and spin coating conditions. The external quantum efficiency of photovoltaic devices fabricated with vertically segregated blend is found to be 4 times higher than that of devices made with laterally segregated blends.

scholarly journals Tailoring hydrogel microstructure via phase separation and kinetic trapping

2021 ◽  
Author(s):  
Simon Vieth
Keyword(s):  
Phase Separation ◽  
Drug Release ◽  
Controlled Drug Release ◽  
Continuous Phase ◽  
The Other ◽  
Phase Iii ◽  
Droplet Growth ◽  
Aqueous Mixtures ◽  
Kinetic Trapping ◽  
Over Time

Control of the microstructure of a biopolymeric phase-separated system is presented as part of an effort to develop a novel platform for controlled drug release. Under certain conditions, aqueous mixtures of biopolymers exhibit thermodynamic incompatibility and separate into distinct phases, each concentrated in one component and poor in the other. Upon initiation of phase separation (PS), droplets of one phase, the included phase, appear and ripen over time such that shared surface area with the continuous phase is minimized. Gelation is a means of halting droplet growth prior to bulk PS (BPS). The purpose of this research is to establish the means to dictate the microstructure of a PS system by: (i) understanding the effects of biopolymer concentration on PS temperature, TPS; (ii) modeling the growth of droplets within the included-phase; (iii) examining the efficacy of gelation as a means of trapping microstructure and (iv) investigating the characteristic microstructures of biopolymer systems undergoing a two-step temperature quench.

scholarly journals Tailoring hydrogel microstructure via phase separation and kinetic trapping

2021 ◽  
Author(s):  
Simon Vieth
Keyword(s):  
Phase Separation ◽  
Drug Release ◽  
Controlled Drug Release ◽  
Continuous Phase ◽  
The Other ◽  
Phase Iii ◽  
Droplet Growth ◽  
Aqueous Mixtures ◽  
Kinetic Trapping ◽  
Over Time

Control of the microstructure of a biopolymeric phase-separated system is presented as part of an effort to develop a novel platform for controlled drug release. Under certain conditions, aqueous mixtures of biopolymers exhibit thermodynamic incompatibility and separate into distinct phases, each concentrated in one component and poor in the other. Upon initiation of phase separation (PS), droplets of one phase, the included phase, appear and ripen over time such that shared surface area with the continuous phase is minimized. Gelation is a means of halting droplet growth prior to bulk PS (BPS). The purpose of this research is to establish the means to dictate the microstructure of a PS system by: (i) understanding the effects of biopolymer concentration on PS temperature, TPS; (ii) modeling the growth of droplets within the included-phase; (iii) examining the efficacy of gelation as a means of trapping microstructure and (iv) investigating the characteristic microstructures of biopolymer systems undergoing a two-step temperature quench.

Reducing the Risk in Controlled Drug Release by Using Tannic Acid in Liposomal Formulations

2018 ◽  
Vol 68 (12) ◽  
pp. 2925-2918
Author(s):  
Gabriela Cioca ◽  
Maricel Agop ◽  
Marcel Popa ◽  
Simona Bungau ◽  
Irina Butuc
Keyword(s):  
Drug Release ◽  
Tannic Acid ◽  
Release Rate ◽  
Controlled Drug Release ◽  
Toxicity Threshold ◽  
Release System ◽  
Liposomal Formulations ◽  
Cross Linker ◽  
Natural Cross

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.

Nanostructured Ketorolac-Tromethamine/MCF: Synthesis, Characterization and Application in Drug Release System

2018 ◽  
Vol 14 (5) ◽  
pp. 432-439 ◽  
Author(s):  
Juliana M. Juarez ◽  
Jorgelina Cussa ◽  
Marcos B. Gomez Costa ◽  
Oscar A. Anunziata
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Therapeutic Efficacy ◽  
Drug Delivery Systems ◽  
Controlled Drug Release ◽  
Delivery Systems ◽  
The Body ◽  
Fickian Diffusion ◽  
Ketorolac Tromethamine

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.

scholarly journals Magnetic hyperthermia controlled drug release in the GI tract: solving the problem of detection

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Joseph C. Bear ◽  
P. Stephen Patrick ◽  
Alfred Casson ◽  
Paul Southern ◽  
Fang-Yu Lin ◽  
...  
Keyword(s):  
Drug Release ◽  
Controlled Drug Release ◽  
Magnetic Hyperthermia ◽  
Gi Tract

Improvement of Medication Adherence and Controlled Drug Release by Optimized Acetaminophen Formulation

2021 ◽  
Author(s):  
Suyoung Been ◽  
Jeongmin Choi ◽  
Young Hun Lee ◽  
Pil Yun Kim ◽  
Won Kyung Kim ◽  
...  
Keyword(s):  
Medication Adherence ◽  
Drug Release ◽  
Controlled Drug Release

scholarly journals Photo-Responsive Supramolecular Micelles for Controlled Drug Release and Improved Chemotherapy

2020 ◽  
Vol 22 (1) ◽  
pp. 154
Author(s):  
Fasih Bintang Ilhami ◽  
Kai-Chen Peng ◽  
Yi-Shiuan Chang ◽  
Yihalem Abebe Alemayehu ◽  
Hsieh-Chih Tsai ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Drug Release ◽  
Visible Light ◽  
Cancer Cells ◽  
Laser Irradiation ◽  
Reactive Oxygen ◽  
Controlled Drug Release ◽  
Grand Challenge ◽  
Supramolecular System ◽  
Oxygen Species

Development of stimuli-responsive supramolecular micelles that enable high levels of well-controlled drug release in cancer cells remains a grand challenge. Here, we encapsulated the antitumor drug doxorubicin (DOX) and pro-photosensitizer 5-aminolevulinic acid (5-ALA) within adenine-functionalized supramolecular micelles (A-PPG), in order to achieve effective drug delivery combined with photo-chemotherapy. The resulting DOX/5-ALA-loaded micelles exhibited excellent light and pH-responsive behavior in aqueous solution and high drug-entrapment stability in serum-rich media. A short duration (1–2 min) of laser irradiation with visible light induced the dissociation of the DOX/5-ALA complexes within the micelles, which disrupted micellular stability and resulted in rapid, immediate release of the physically entrapped drug from the micelles. In addition, in vitro assays of cellular reactive oxygen species generation and cellular internalization confirmed the drug-loaded micelles exhibited significantly enhanced cellular uptake after visible light irradiation, and that the light-triggered disassembly of micellar structures rapidly increased the production of reactive oxygen species within the cells. Importantly, flow cytometric analysis demonstrated that laser irradiation of cancer cells incubated with DOX/5-ALA-loaded A-PPG micelles effectively induced apoptotic cell death via endocytosis. Thus, this newly developed supramolecular system may offer a potential route towards improving the efficacy of synergistic chemotherapeutic approaches for cancer.

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