Drug delivery is the process of administering pharmaceutical substances to targeted areas in the body. It plays a vital role in the effective treatment of various diseases. However, drug delivery is often challenged by the body’s natural defenses, such as the gastrointestinal tract and the immune system, which can prevent the drug from reaching its intended target. Carrageenans, a family of sulfated polysaccharides derived from red seaweed, have been shown to be an effective tool in drug delivery due to their unique properties. Carrageenans are a natural, renewable, and biocompatible source of polymer that can be easily extracted from red seaweed. They are structurally diverse and have a range of…

Gene therapy refers to the introduction of normal foreign genes into target cells to compensate or correct diseases caused by gene defects or abnormalities, so as to achieve the purpose of treatment. Naked DNA usually requires physical methods to enter tissues or cells, and DNA is easily digested and degraded by various enzymes in tissues or cells, resulting in a very low expression level of the encoded protein, which affects the effect of gene therapy. Therefore, the development of gene carriers with low toxicity and high efficiency is one of the urgent problems to be solved in gene therapy. Gene vectors are generally divided into two categories: viral vectors and…

Liposomes are ultra-micro spherical carrier preparations formed by lipid bilayers, and are typical representatives of nano-drug delivery systems. When amphiphilic molecules such as phospholipids are dispersed in the aqueous phase, the hydrophobic tails of the molecules gather together, and the hydrophilic heads are exposed in the aqueous phase to form closed vesicles with a bilayer structure. A variety of drugs of different polarities can be encapsulated in the water phase and bimolecular membrane in the vesicles. In addition, liposomes have good biocompatibility and can be normally metabolized. Therefore, liposomes have great potential for development as drug carriers. The mechanism of action of the liposome drug delivery system can be divided…

Natural polysaccharides have the characteristics of high safety, good stability and degradability, and are easy to be chemically modified and modified, such as heparin, chitosan, hyaluronic acid and hydroxyethyl starch, and are widely used in nano-drug delivery systems. However, chitosan has poor water solubility and needs to be modified with polyethylene glycol; although hyaluronic acid can improve the selectivity of drugs to tumor cells, it is easy to accumulate in the liver and kidney and cause toxic side effects. Both hydroxyethyl starch and heparin have good hydrophilicity and biocompatibility, but heparin also has its unique natural advantages: 1. Inhibition of angiogenesis-mediated anti-tumor activity; 2. Anti-tumor metastasis activity; 3. Tumor targeting.…

Nanotechnology has not only received attention and applications in the field of drug delivery, but also has achieved many successes in the field of tissue engineering. Nano dressings can be defined as dressings in which nanomaterials are the matrix. The birth of nano dressings has brought new treatment methods for wound repair and burn care, such as nanohydrogels, nanofibers, nanomembranes, dendrimers, and polymer conjugates (acting as drugs release in the process of wound treatment, growth factor supplementation and/or artificial skin effect). The role of nano-dressing includes anti-bacterial and anti-inflammatory, acting on tissue functional cells, optimizing and improving the matrix, and promoting the proliferation and differentiation of stem cells. Features of…

Microneedles are delicate clusters of fine needles made by micro-manufacturing technology. The length is 1-150μm, which is enough to penetrate the stratum corneum or active epidermis of human skin, but does not touch the nerves, has no pain, and has continuous promotion of drug transdermal delivery. Microneedle technology has the comprehensive characteristics of subcutaneous injection and ordinary transdermal patches. Its advantages include: 1. It can deliver macromolecules through the stratum corneum, and is suitable for the transdermal delivery of peptides, proteins and other macromolecular drugs, and even drug-loaded nanoparticles; 2. Compared with the painful subcutaneous injection, the microneedle is almost non-invasive and painless, and has good patient compliance; 3. The…

Detergents are amphipathic molecules with a polar portion and a hydrophobic portion. Detergents respond to an aqueous environment following the same principles as do membrane lipids. What Are the Forms of Detergents? Detergents can exist in three environments in aqueous media. Detergents have a limited solubility in the aqueous phase, characterized by the CMC, or critical monomer concentration (or critical micelle concentration). Above the CMC, detergents form micelles. In the presence of membranes, detergents can also partition into the membrane. In the latter case, sufficient detergent will lead to transfer of membrane components, including membrane lipids and membrane proteins, into the detergent micelles. What can Detergents Used for? Detergent micelles can…

The eye is a special sensory organ of the human body and an important part of the body. Ocular lesions are closely related to and interact with other tissue system lesions throughout the body. The special structure and physiological characteristics of the eye make ophthalmic drugs have their own characteristics in the way and route of administration. Most drugs enter the aqueous humor through the cornea, and then are distributed in surrounding tissues, such as the ciliary body, lens, vitreous body, choroid, retina, and a small amount of drugs enter the pigment membrane and vitreous body through the conjunctiva and sclera . There is a barrier between the tissue fluid…

Most ophthalmic drugs are administered locally in the conjunctival sac, and the most commonly used dosage form is eye drops. Due to various physiological barriers, the eye bioavailability of eye drops is extremely low, generally less than 5%. On the one hand, the main reason is the rapid elimination rate of the drug on the ocular surface and short residence time. Most of the drugs instilled in the eye are lost quickly with the tears (partly absorbed by the conjunctiva and nasal mucosa into the systemic circulation), and partly bound by the contents of the tears or Decomposition; On the other hand, the absorption of the corneal route and the…