Related Experiment Video
Updated: Jun 19, 2026
07:45
Electrophoretic Crystallization of Ultrathin High-performance Metal-organic Framework Membranes
Published on: August 16, 2018
Diffusional properties of zein membranes and matrices
Yoon K Oh1, Douglas R Flanagan
1Division of Pharmaceutics, College of Pharmacy, University of Iowa, Iowa City, Iowa 52242, USA. yoon.k.oh@gsk.com
Drug Development and Industrial Pharmacy
|October 24, 2009
Summary
Zein protein forms aqueous channels upon hydration, influencing drug diffusion. These channels, dependent on permeant solubility and matrix properties, are key to controlled release formulations.
Area of Science:
- Biomaterials Science
- Pharmaceutical Technology
- Polymer Science
Background:
- Zein, a hydrophobic corn protein, is explored for biodegradable pharmaceutical applications.
- Previous studies indicated zein's swelling behavior impacts permeation.
- Understanding zein's diffusion properties is crucial for controlled release systems.
Purpose of the Study:
- To investigate the diffusional behavior of model drugs in zein systems.
- To characterize diffusional parameters like effective diffusion coefficients, porosity, and tortuosity.
- To propose an alternative method for calculating porosity and tortuosity.
Main Methods:
- Analysis of drug release and membrane diffusion profiles.
- Calculation of effective diffusion coefficients, porosities, and tortuosities.
- Experimental investigation of zein matrices and membranes.
Main Results:
- Zein systems exhibit diffusion primarily through aqueous channels formed during hydration and swelling.
- Drug permeation and release are influenced by permeant solubility and matrix/membrane permeability.
- Calculated parameters support the proposed aqueous channel model for zein diffusion.
Conclusions:
- Zein matrices and membranes hydrate and swell, creating dominant aqueous diffusional pathways.
- The findings support the aqueous channel model for understanding drug diffusion through zein.
- Zein's properties make it a promising material for controlled drug delivery systems.
Related Concept Videos
01:24Protein Diffusion in the Membrane
Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...
00:59Mechanisms of Membrane Domain Formation
Different physical properties of lipids and proteins allow them to localize and form distinct islands or domains in the membrane. Some membrane domains are formed due to protein-protein interactions, whereas others are formed due to the presence of specific lipids such as sphingolipids and sterols—for example, large proteins, such as bacteriorhodopsin, aggregate and create distinct domains.
Another mechanism for membrane domain formation involves membrane proteins interacting with cytoskeletal...
Another mechanism for membrane domain formation involves membrane proteins interacting with cytoskeletal...
01:26Membrane Fluidity
Membrane fluidity is explained by the fluid mosaic model of the cell membrane, which describes the plasma membrane structure as a mosaic of components—including phospholipids, cholesterol, proteins, and carbohydrates—that gives the membrane a fluid character.
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
01:23Membrane Fluidity
Cell membranes are composed of phospholipids, proteins, and carbohydrates loosely attached to one another through chemical interactions. Molecules are generally able to move about in the plane of the membrane, giving the membrane its flexible nature called fluidity. Two other features of the membrane contribute to membrane fluidity: the chemical structure of the phospholipids and the presence of cholesterol in the membrane.Fatty acids tails of phospholipids can be either saturated or...
01:18Membrane Domains
The membrane domains concentrate specific lipids and proteins at one place within the membrane, which helps in cell signaling, adhesion, and other critical cellular processes. These domains can differ in size, composition, function, and lifespan.
Protein Domains
The membrane comprises a group of distinct proteins responsible for carrying out a cell's specific function. For example, the plasma membrane of the human sperm, or a single germ cell, contains a unique set of proteins in the anterior...
Protein Domains
The membrane comprises a group of distinct proteins responsible for carrying out a cell's specific function. For example, the plasma membrane of the human sperm, or a single germ cell, contains a unique set of proteins in the anterior...
01:17Passive Diffusion: Overview and Kinetics
Passive diffusion is a critical process that allows small lipophilic drugs to cross the cell membrane along a concentration gradient. This mechanism's efficiency depends on four primary factors: the membrane's surface area, the drug's lipid-water partition coefficient, the concentration gradient, and the membrane's thickness.
When administered orally, drugs establish a substantial concentration gradient between the gastrointestinal (GI) lumen and the bloodstream, expediting their diffusion into...
When administered orally, drugs establish a substantial concentration gradient between the gastrointestinal (GI) lumen and the bloodstream, expediting their diffusion into...