-
Liposome Preparation Method 1
Phospholipids are generally white or light yellow powders or lumps at room temperature. They are very soluble in chloroform and can also be dissolved in ether, n-hexane or ethanol, and are almost insoluble in water or acetone. Disperse the phospholipid molecules into the aqueous solution by hydration treatment after high dispersion, or changing the solvent. When the concentration reaches the critical micelle concentration (CMC), self-assembly occurs through the hydrophobic interaction to form a bilayer structured liposome bubble. Commonly used preparation methods of liposomes in the laboratory include thin film method, reverse evaporation method, double emulsion method, centrifugal method, injection method, calcium fusion method, ammonium sulfate gradient method, etc. In order to ensure the final smooth transition to…
-
Phospholipids—the Basic Composition of Liposomes
Phospholipids are the basic materials composing liposomes, which also determine the liposome’s physical and chemical properties. Factors affecting the stability of liposome formulations include the phase transition temperature and electric charges associated with phospholipids, the particle size associated with the manufacturing process, and the temperature, pH, and ionic strength associated with the environment. The type and amount of phospholipids are essential for the preparation of liposomes. Classification of Phospholipids Phospholipids are divided into phosphoglycerides and sphingomyelins by structure. Glycerol phosphate (PG) is composed of a hydrophilic polar head and two hydrophobic tails. The 1st and 2nd hydroxyl groups on the glycerol skeleton are esterified with fatty acids, and the 3rd…
-
Application of Liposome as Drug Carrier
Liposomes are bilayer vesicles composed of phospholipids as the main material, and were first discovered by Bangham, a British scientist. Liposome’s structure is similar to biofilm, also known as artificial biofilm, and is widely used to study the structure and function of biofilm. Liposome used as a drug carrier began in the early 1970s. Due to the advantages of biocompatibility, biodegradability, non-toxicity and non-immunogenicity, liposomes have rapidly developed as new drug dosage forms. After more than 40 years of research, there are currently 12 liposomal preparations on the market. The drugs involved include adriamycin hydrochloride, amphotericin, muramyl-tripeptide, paclitaxel, gentamicin, and cytosine arabinoside, etc. In addition, various types of liposomes are…
-
Nanocarrier System Targeting Stromal Organelles
With the development of biomedicine, some diseases are clinically found to be caused by organelle lesions. And the drugs used to treat these diseases not only need to cross the cell membrane to enter the cell, but also need to target specific organelles to play a role. Therefore, in the development of drugs for these diseases, suitable carriers are needed to help the drugs target the target organelles. With the development of nanotechnology, researchers have found that nanosystems have obvious advantages in the field of organelle targeting. Therefore, more and more nanoparticles are used to target the endoplasmic reticulum, lysosomes and mitochondria. Mitochondrial Targeting Mitochondria play a very important role…
-
Application Prospects of Targeted Nano Drug Delivery System
Targeted drugs were proposed by German scientist and Nobel Prize winner Ehrlich in 1906 and have a history of more than 100 years. Until the late 1970s, with the advancement of molecular biology, cell biology, and materials science, targeted formulations developed rapidly, and products began to be marketed. The nano drug delivery system is distributed in specific organs, tissues, cells, and even intracellular structures in the body through passive targeting, active targeting, physical and chemical targeting, etc., and changes the distribution of prototype drugs in vivo. With the leapfrog development of life sciences, human understanding of disease pathogenesis and drug action mechanisms has transitioned from a macroscopic overall level to…
-
Nuclear Targeted Nano Drug Carrier
The nucleus is the place where the genetic material in the cell is stored, copied and transcribed, and plays an important role in the metabolism, growth and differentiation of the cell. Therefore, the nucleus is also the site of action for various drugs such as DNA, intercalators, alkylating agents, and topoisomerase inhibitors. The nuclear membrane is composed of two layers of membranes on which nuclear pore complexes (NPCS) exist. The nuclear membrane will disappear only when the cell undergoes mitosis. In other cases, the only way for large molecules to enter the nucleus is the nuclear pore complex, which allows particles with a diameter of 9 nm or molecules with a…
-
Cytoplasm Targeted Nano Drug Carrier
The cytoplasm is the general term for all translucent, colloidal, granular materials except the nuclear area surrounded by the cytoplasmic membrane, and is composed of the cytoplasmic matrix, endomembrane system, cytoskeleton, and inclusions. Among them, the cytoplasmic matrix, also known as cytosol, is a homogeneous and translucent colloid in the cytoplasm, which is filled between other tangible structures; its main function is to provide an ionic environment for various organelles to maintain their normal structure and supply all substrates for various organelles to complete functional activities, and is also the venue for certain biochemical activities. The importance of cytoplasmic matrix transport is not only due to the existence of multiple drug targets in the matrix…
-
Colon-Targeted Nanoparticles
The colon is located between the cecum and rectum and is divided into four parts: the ascending colon, the transverse colon, the descending colon, and the sigmoid colon. Its main function is to absorb water and electrolytes and solidify the contents into feces. The colon cannot actively absorb substances such as sugar, amino acids, and small molecule peptides. Its absorption function is mainly achieved by the content of the colon staying for a long time. Some drugs can be absorbed by passive diffusion. The physiological environment of the colon has the following characteristics: ① The pH is generally 6.5 to 7.5, which varies depending on the diet structure and physiological…
-
Eye Targeted Nano Drug Delivery System
The eye is divided into anterior and posterior segments. The anterior segment includes the cornea, conjunctiva, iris, aqueous humor, and ciliary body. The posterior segment includes the vitreous, retina, choroid, and sclera. The physiological barriers of the eye include the corneal and conjunctival barriers, the aqueous humoral barrier, and the blood-retinal barrier. The cornea and retina are barriers that are not easily penetrated by drugs. The drug absorption of eye drops usually has a corneal route and a non-corneal route. Fat-soluble drugs enter the aqueous humor from tears mainly through the corneal pathway. In the non-corneal pathway, the drug penetrates into the human eye tissue through the conjunctiva and sclera,…
-
Kidney-targeted Nanoparticles
Common kidney diseases include pathological changes in primary and secondary glomeruli, renal tubules, renal mediators, and renal blood vessels. In the clinical treatment of kidney disease, hormone shock treatment is often used, supplemented by triptolide tablets and other drugs for maintenance treatment. The toxic and side effects of large doses of hormones and maintenance drugs severely limit the continuous treatment of kidney disease. When kidney disease develops to a later stage, chronic renal failure will occur, and patients have to rely on expensive hemodialysis or kidney transplantation to prolong life, which will bring a heavy burden on patients’ families and society. It is of great significance to research and develop…
