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What Are Block Copolymer Micelles?
Block copolymer micelles are generally formed by the self-assembly of either amphiphilic or oppositely charged copolymers in aqueous medium. The hydrophilic and hydrophobic blocks form the corona and the core of the micelles, respectively. Block copolymer micelles can be classified according to the type of intermolecular forces driving the segregation of the core segment from the aqueous milieu. In the past few decades, at least three main categories were identified, viz. amphiphilic micelles (formed by hydrophobic interactions), polyion complex micelles (PICM; resulting from electrostatic interactions), and micelles stemming from metal complexation. Generally, when the hydrophilic segment is longer than the core block, the shape of the resulting micelles is spherical. Conversely, increasing…
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Lung Inhalation Nano Drug Delivery System Dosage Form
The existing pulmonary inhalation nano drug delivery system dosage forms are mainly divided into two types: liposomes and nanoparticles. Liposomes Among the various dosage forms for pulmonary administration, liposomes have obvious advantages, such as being suitable for encapsulating lipophilic drugs, avoiding local irritation, enhancing curative effects, reducing toxic and side effects, and evenly distributing active drugs in the lungs. Lung-administered liposomes can also be used for gene therapy. Compared with viral vectors, liposomes are simple to prepare, have no damage to normal tissues, and have high safety. Liposome pulmonary drug delivery has the following characteristics: 1. The main component of alveoli is lipids, among which phospholipids account for 80% of…
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What Are Natural Phospholipids?
Lipids are defined as apolar molecules comprising as major classes fatty acids and fatty acid esters of normally natural origin. Non-natural components, such as dicarba-closo-dodecaboranes (in short carboranes) can also form acids and esters, which reveal lipid-like properties. Phospholipids are lipids usually composed of three components: a diglyceride, a phosphate group and another organic molecule such as choline, to produce phosphatidylcholine. Phospholipids are a major component of all cellular membranes and can form bilayers. What Are Examples of Phospholipids? The most common phospholipids are phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and phosphatidylserine. These phospholipids share the common features of fatty acids esterified to the 1 and 2 positions of the glycerol backbone with the phosphate…
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What Are PEGs?
PEGs (polyethylene glycols) are composed of polyether compounds repeating ethylene glycol units according to the constituent monomer or parent molecule (as ethylene glycol, ethylene oxide, or oxyethylene) (Fig. 1). Most PEGs are commonly available commercially as mixtures of different oligomer sizes in molecular weight (MW) ranges. For instance, PEG-10,000 typically designates a mixture of PEG molecules (n = 195 to 265) having an average MW of 10,000. PEG is also known as polyethylene oxide (PEO) or polyoxyethylene (POE), with the three names being chemical synonyms. However, PEGs mainly refer to oligomers and polymers with molecular masses below 20,000 g/mol, while PEOs are polymers with molecular masses above 20,000 g/mol, and POEs are…
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Liposomes for Cosmetics
Liposomes are spherical vesicles in which their central aqueous section is surrounded by one or more of a bilayer membrane (Lamella) that is frequently enclosed by aquatic environments. These vesicles are formed when amphiphilic lipids confront with aqueous milieu. They can vary in size from 15 nm to several microns. In the last 30 years, the application of liposome has been expanded from drug delivery to the cosmetic field and it is the most widely known cosmetic delivery system nowadays. What AreLiposomes in Cosmetics? Liposomes can act as dermal delivery carriers due to their being small, unilamellar, and designed with membrane flexibility. Therefore, liposomes are commonly used in dermal applications, either as protective…
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Advantages of Nanoparticles in Transdermal Drug Delivery
Nanoparticles are a kind of nanomaterials with high dispersion characteristics. It can pass through the hair follicle or stratum corneum, thereby improving the transdermal absorption of the drug and the sustained release of the drug, and can protect the drug from degradation. Solid lipid nanoparticles (SLN) is a new type of nano-drug carrier developed in the 1990s. It uses natural or synthetic lipid materials (such as lecithin, triglycerides, etc.) as a carrier to wrap and adsorb drugs on A solid colloidal particle drug delivery system formed in the lipid core. A certain proportion of liquid oil or mixed lipids is used to replace the solid lipids in the solid lipid nanoparticles to form a…
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Lung Inhalation Nano Drug Delivery System
Lung diseases, such as asthma, emphysema, chronic obstructive pulmonary disease, and cystic fibrosis, are increasing with the increase in air pollution. In lung therapy, the use of systemic drug delivery is prone to cause adverse reactions, and the distribution of drugs in the lungs may be less, so the development of lung inhalation drug delivery systems has become a research hotspot. People have recognized that lung inhalation is the simplest and most effective route of administration for the treatment of the above diseases. At the same time, the lungs are also a good absorption site for systemic administration. The advantages of pulmonary drug delivery include: 1, The lungs have a large absorption area. Adults have…
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Liposomes for DNA/RNA Delivery
Liposomes are vesicular structures, and the unique advantages imparted by lipid vesicles are their diverse range of morphologies, compositions, abilities to envelope and protect many types of therapeutic biomolecules, lack of immunogenic response, low cost, and their differential release characteristics. These characteristics have led to applications in chemical and biochemical analytics, cosmetics, food technologies, and drug and gene delivery. There are numerous lipid formulations for each of these applications. This article is mainly about the use of liposomes for gene delivery. Which Type of Liposomes Are Used for Gene Delivery? Liposomes are generally formed by the self-assembly of dissolved lipid molecules, each of which contains a hydrophilic head group and…
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Application of Nanoemulsion in Transdermal Drug Delivery
Nanoemulsion has a particle size between 20-200nm, and its particle size is more suitable for drug loading and targeting. Nanoemulsion as a drug carrier has the following characteristics: 1. Nanoemulsion has the characteristics of solubilization and sensitization; 2. Nanoemulsion is simple to prepare, good physical stability, etc., and can be sterilized; 3. Nanoemulsion can simultaneously contain different Fat-soluble drugs, improve the stability of some unstable drugs; 4. Nanoemulsions increase the bioavailability of macromolecular drugs; 5. Nanoemulsions can improve the solubility of insoluble drugs; 6. Nanoemulsions have low viscosity; 7. Nanoemulsions The diameter is small and uniform, which can improve the dispersion of the encapsulated drug, and protect the easily hydrolyzed…
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What Are Liposomes?
Liposomes are small artificial sphere-shaped vesicles consisting of one or more phospholipid bilayers, which were first described in the mid-60s. Today, they are a very useful reproduction, reagent, and tool in various scientific disciplines, including mathematics and theoretical physics, biophysics, chemistry, colloid science, biochemistry, and biology. Since then, liposomes have made their way to the market. Due to their size and hydrophobic and hydrophilic character(besides biocompatibility), liposomes are promising systems for drug delivery. Among several talented new drug delivery systems, liposomes characterize an advanced technology to deliver active molecules to the site of action, and at present, several formulations are in clinical use. Research on liposome technology has progressed from conventional…
