-
How Does the Drug Enter the Human Body Through the Skin?
Transdermal drug delivery systems in a broad sense include topical drug delivery systems and transdermal drug delivery systems (TDDS). The former acts on the skin or subcutaneous tissue; the latter is the absorption of drugs into the blood through the skin. Compared with oral or injection administration, the advantages of the transdermal drug delivery system include: 1. No gastrointestinal irritation; 2. Avoid the first pass effect of the liver 3. Get a controlled release effect; 4. Easy to use, good patient compliance; 5. High safety , Easy to remove; 6. less skin tissue degrading enzymes, can be used for the administration of macromolecular drugs. Global sales of transdermal drug delivery preparations reached US$12.7 billion in 2005, US$21.5 billion in…
-
New Study Solving the Puzzle of Polymers Binding to Ice for Biological Cryopreservation
Understanding the ice recrystallization inhibition (IRI) activity of antifreeze biomimetics is critical to the development of next-generation cryoprotectants. Recently, in the paper, The atomistic details of the ice recrystallization inhibition activity of PVA, which is published in the journal Nature Communications, researchers from the University of Warwick have found that, contrary to the emerging consensus, shorter or longer polymer chains of poly(vinyl)alcohol (PVA) all bind to ice. In this study, the researchers bring together molecular dynamics simulations and quantitative experimental measurements to unravel the microscopic origins of the IRI activity of poly(vinyl)alcohol (PVA)—the most potent of biomimetic IRI agents. Contrary to the emerging consensus, the team find that PVA does not require a “lattice matching” to…
-
Researchers Stabilize the Collapsing Metal-organic Frameworks by Adding a Polymer
High internal surface area is a highly sought after asset in material design, bringing metal-organic frameworks (MOFs) at the forefront of materials research. In fact, the main focus in this field is to create innovative methods to maximize the surface area of the MOF. Nevertheless, macroporous MOFs, especially those with mesopores, still face the problem of pore collapse during activation. In a study published in the Journal of the American Chemical Society, the researchers have solved this problem by adding a small amount of polymer to the MOF pores, which prevents the pores from collapsing. MOFs are a special kind of sponge-like materials with nano-scale pores which have many applications, such as carbon capture…
-
In Vitro Evaluation Method of Oral Nano Drug Delivery System
The in vitro evaluation method of oral nano-drug system is a simple and rapid method to evaluate the transport and absorption of oral nano-drug. This method is simple and easy to implement, has good reproducibility, and the experimental environment and conditions are easy to control, so that the influencing factors are singularized and simplified, but it cannot reflect the actual absorption state of the drug in the body. This method is often used to study the intestinal absorption mechanism of the nano drug delivery system. The method mainly includes inverted intestinal sac method, intestinal piece incubation method, membrane vesicle method, cell culture model method, parallel artificial membrane permeability determination method, computer…
-
Carrier And Biological Level Evaluation Method of Oral Nano-Drug Delivery System
The oral nano-drug system is evaluated at the body level mainly through intact animals, which have complete blood supply and innervation to ensure that the intestinal nerves are intact and directly reflect drug absorption. This evaluation method can be used to study drug penetration and absorption kinetics. The related detection methods mainly include: in vivo intestinal perfusion method, intestinal loop method, intestinal vascular intubation method and nitrogen measurement method. Intestinal Perfusion In vivo intestinal perfusion is to insert a double-lumen tube into the intestine through the mouth (in experimental animals, the perfusion tube and the drainage tube are inserted into the proximal and distal ends of the intestine respectively through…
-
Want A Quick Understanding for Your Dendrimers?Read This!
What Are Dendrimers? Dendrimers are nano-sized, radially symmetric molecules with well-defined, homogeneous, and monodisperse structure consisting of tree-like arms or branches. These hyperbranched molecules were first discovered by Fritz Vogtle in 1978, by Donald Tomalia and co-workers in the early 1980s, and at the same time, but independently by George R. Newkome. A variety of dendrimers exist, and each has biological properties such as polyvalency, self-assembling, electrostatic interactions, chemical stability, low cytotoxicity, and solubility. These varied characteristics make dendrimers a good choice in the medical field, and support their diverse applications, such as drug delivery, gene delivery, magnetic resonance imaging contrast agents, and photodynamic therapy. Are Dendrimers Polymers? Dendrimers are synthetic polymeric…
-
Two Recent Research Progress on Polymers
Sugar-Based Polymers from d-Xylose: Living Cascade Polymerization, Tunable Degradation, and Small Molecule Release Biodegradable bio-based polymers provide options for chemical recycling, and they can be used for storing and releasing useful molecules. Scientist Tae-Lim Choi and colleagues from Seoul National University, South Korea, have developed a class of sugar-based polymers that can be degraded by acid hydrolysis. The researchers also integrated “cargo” molecules in the polymer, which are designed to break apart after the polymer degrades. The study, published in the journal Angewandte Chemie, stated that degradable cargo polymers are very important for medical and sensor applications. In this study, enyne monomers derived from D-xylose underwent living cascade polymerizations to prepare…
-
Oral Nano Drug Delivery System Absorption Mechanism
Oral absorption of nanomedicine means that nanomedicine enters the blood circulation through the gastrointestinal tract. Nanomedicine has a very complicated process after entering the body, interacting with the components in the biological system (such as proteins and cells), and has unique distribution, clearance, metabolism and immune response behaviors in the body. There are three main ways for nanoparticles to be absorbed in the gastrointestinal tract: 1. Cell bypass channel transport; 2. Transcellular uptake by intestinal epithelial cells; 3. Phagocytosis by microfold cells (M cells) in Peyer’s patches in the ileum. Absorption through M cells is the main absorption route of oral nanoparticles. When the nanoparticles enter the gastrointestinal tract, part…
-
Oral Drug Absorption Barrier
Oral drugs enter the gastrointestinal tract by mouth, and then undergo digestion and absorption in the gastrointestinal tract. Studies have shown that the gastrointestinal mucosa is attached to the gastrointestinal tract, which is a key barrier affecting the absorption of oral drugs. Studies have found that the gastrointestinal mucosa is covered with a 100-150gm thick aqueous mucosa layer secreted by goblet cells, which is the rate-limiting step for the drug to reach the surface of intestinal epithelial cells. Below the mucosal layer are columnar epithelial cells with tight junctions. In the cell layer there are intestinal epithelial cells, goblet cells, endocrine cells and Peyer’s cells. The epithelial cell layer faces…
-
New Research Reveals the Molecular Mechanism of Cardiolipin
Cardiolipin is a unique phospholipid with a very interesting chemical and specific ultrastructural characteristics. In a research report published in the journal Science Advances in 28 Aug 2020, scientists from Johns Hopkins University and other institutions studied yeast and revealed the molecular mechanism of the fatty compound cardiolipin that helps produce cellular energy. This related research results are expected to help clarify the pathogenesis of diseases that affect human metabolism, such as heart disease, diabetes, and Bath syndrome. Cardiolipin is present in almost every cell of the body. It is located in the maze of cell membranes that make up mitochondria. It is believed to help mitochondria produce mitochondria create adenosine triphosphate (ATP), which is a…
