Related Experiment Video
Updated: Jun 25, 2026
11:55
Membrane Transport Processes Analyzed by a Highly Parallel Nanopore Chip System at Single Protein Resolution
Published on: August 16, 2016
Discriminating the molecular pathways during uptake and release on nanoporous host systems
1Department of Interface Physics, Faculty of Physics and Earth Science, University of Leipzig, Linnéstrasse 5, 04103 Leipzig, Germany. heinke@physik.uni-leipzig.de
The Journal of Chemical Physics
|February 5, 2009
Summary
Optical techniques reveal transient concentration profiles in nanoporous materials, allowing direct measurement of intracrystalline transport diffusion. This enables accurate determination of molecular flux fractions entering or leaving host crystals through different faces.
Area of Science:
- Materials Science
- Physical Chemistry
- Nanotechnology
Background:
- Nanoporous materials are crucial in various applications, necessitating understanding of molecular transport.
- Observing intracrystalline diffusion dynamics is key to optimizing material performance.
Purpose of the Study:
- To demonstrate how optical techniques can quantify molecular flux fractions during uptake/release in nanoporous hosts.
- To validate analytical solutions for calculating these fractions using experimental data.
Main Methods:
- Utilizing interference microscopy to observe transient concentration profiles.
- Performing numerical calculations on various molecular uptake processes.
- Applying analytical solutions for constant and mean transport parameters.
Main Results:
- Optical techniques provide direct access to intracrystalline transport parameters.
- Molecular flux fractions can be reasonably calculated using analytical solutions with mean transport parameters.
- Even with anisotropic mass transfer, deviations are typically under 8%.
Conclusions:
- Experimental determination of transient concentration profiles offers novel insights into molecular transport.
- Simplified calculation methods provide accurate estimations of flux fractions.
- This approach enhances the understanding and design of nanoporous materials.
Related Concept Videos
01:17Pore Transport and Ion-Pair Transport
Pore transport and ion-pair formation are critical mechanisms for the absorption and distribution of drugs in the body.
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct microscopic...
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct microscopic...
01:23Mechanisms of Drug Absorption: Paracellular, Transcellular, and Vesicular Transport
Drugs need to permeate cell membranes to reach their target sites after administration. Orally administered drugs must transcend intestinal epithelial membrane barriers to infiltrate the systemic circulation. Drugs with a molecular weight of less than 500 Daltons diffuse through gaps between neighboring cells, called paracellular pathways.
However, most drugs use the transcellular route, traversing directly through the cell membranes via two mechanisms: passive and active transport. Passive...
However, most drugs use the transcellular route, traversing directly through the cell membranes via two mechanisms: passive and active transport. Passive...
01:44The Significance of Membrane Transport
The transport of solutes across the cell membrane is essential for metabolic processes, like maintaining cell size and volume, generating the action potential, exchanging nutrients and gases, etc. Membrane transport can be either passive or active. It can be simple diffusion, facilitated, or mediated transport aided by transport proteins such as transporters and channels.
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
01:24Cellular Membranes and Drug Transport
Drugs must traverse multiple biological barriers, such as multi-layered skin, single-layered intestinal epithelium, and the plasma membrane, to reach their target sites within the body. The plasma membrane, a highly structured composite of phospholipids, carbohydrates, and proteins, is the cell's protective boundary, facilitating selective substance exchange.
Phospholipids arrange themselves into a bilayer, with hydrophilic heads oriented outward and hydrophobic tails facing inward.
Phospholipids arrange themselves into a bilayer, with hydrophilic heads oriented outward and hydrophobic tails facing inward.
01:06Carrier-Mediated Transport
Carrier-mediated transport is a pivotal process in drug absorption, particularly for lipid-insoluble drugs, and encompasses facilitated diffusion and active transport. Facilitated diffusion allows drugs to move along their concentration gradient without energy expenditure, while active transport utilizes ATP to drive drug movement against this gradient.
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
01:16Facilitated Diffusion
The plasma membrane, a critical structure in cellular biology, houses an array of transporters, or carrier proteins, interspersed within its lipid bilayer. These proteins play a crucial role in solute transport through facilitated diffusion, a form of passive diffusion that uses transporters to move the molecules across the membrane.
In this process, substrates such as organic compounds and ions interact with a transporter on one side, triggering conformational changes in proteins that enable...
In this process, substrates such as organic compounds and ions interact with a transporter on one side, triggering conformational changes in proteins that enable...