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What are Metal Nanoclusters
Metal nanoclusters are a kind of nanomaterials with a size of less than 2 nm and stacked by 1 to 150 metal atoms. Metal nanoclusters have a typical core-shell structure, consisting of a metal atomic core and a ligand molecular shell. Ligands are usually substances that have strong covalent interaction with metal atoms such as amino groups, sulfhydryl groups, and phosphorus groups, such as thiol compounds, dendrimers, polymers, deoxyribonucleic acid (DNA), polypeptides, and proteins. At present, gold nanoclusters (AuNCs), silver nanoclusters (AgNCs), platinum nanoclusters (PtNCs), copper nanoclusters (CuNCs) and other metal nanoclusters have been widely synthesized. In recent years, metal nanoclusters have made remarkable achievements in biomedical fields such as…
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What Are Dextrans?
Dextran is a polysaccharide comprised of d-glucopyranose (d-glucose) repeating units linked through glycosidic linkages. It is biocompatible, biodegradable, and presents antithrombotic and anti-inflammatory properties. Dextran functional hydroxyl (–OH) groups offer an easy point for chemical conjugation with other materials. As an example, dextran can be modified with hydrophobic moieties in order to form dextran-based amphiphiles. These amphiphilic materials can encapsulate poorly water-soluble chemotherapeutics through hydrophobic interactions and self-assemble into nanocarriers. What Are the Chemical Structure and Properties of Dextrans? Dextran consists of α(1,6)-linked glucan with side chains attached to the C-3 position of the backbone (Figure 1). It is synthesized from sucrose by certain lactic acid bacteria, such as leuconostoc…
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What Is Polylactide?
Polylactide (PLA), also the polylactic acid, is the biodegradable hydrolyzable aliphatic semicrystalline polyester that can be produced through the direct condensation reaction of its monomer, lactic acid, as the oligomer, and also by a ring-opening polymerization of the cyclic lactide dimer. Is Polylactic Acid Natural? PLA is a biodegradable, biocompatible, and renewable thermoplastic polyester. The monomer lactic acid (LA) of PLA is derived from natural sources, which is produced using bacterial fermentation of corn, sugarcane, potatoes, sugar beet pulp, and other biomass. What Are the Characteristics of Polylactide? PLA is a very useful material to be used as a replacement for petroleum-based polymers because of its good mechanical properties and…
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What Are Macrocycles?
Macrocycles are generally described as molecules and ions containing twelve- or more-membered rings. Macrocyclic compounds describe a large and mature field of chemistry. The macrocycle often binds ions and facilitates the transport of ions across the hydrophobic membrane and solvent. It wraps the ions with a hydrophobic sheath, which facilitates the phase transfer characteristics. What Are Macrocyclic Effects? The macrocyclic effect is when the multidentate ligand forms a ring with the central metal atom or ion, since it is a multidentate ligand, the stability of the complex is enhanced. The macrocyclic effect is the high affinity of metal cations for macrocyclic ligands compared to their acyclic analogs. What Is a…
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What Are Chelating Agents?
Chelating agents are organic compounds capable of linking together metal ions to form complex ring-like structures called chelates. They are also known as chelants, chelators, or sequestering agents. What Are Natural Chelating Agents? Citric, malic, lactic, and tartaric acids and certain amino acids are naturally occurring chelating agents, but they are not as powerful as EDTA. The EDTA (ethylene-diamine-tetraacetic acid) molecule is a chelating agent widely used in molecular biology to sequester divalent and trivalent metal ions such as calcium and magnesium. What Is a Typical Chelating Agent? An example of a simple chelating agent is ethylenediamine. A single molecule of ethylenediamine can form two bonds to a transition-metal ion…
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What is Nano Dressing
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…
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What is microneedle
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…
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Common Non-Viral Gene Vectors
Gene therapy is the transfection of genes (plasmid DNA, siRNA and miRNA, etc.) into specific cells to promote or inhibit the expression of the target protein to achieve the purpose of treating human diseases. Because RNA and DNA gene fragments are negatively charged and are easily degraded by nucleases, it is difficult to pass through negatively charged cell membranes. Therefore, selecting appropriate gene carriers to protect and transport gene fragments into cells is an urgent problem to be solved. Viral vectors and non-viral vectors are the two most commonly used gene transfer vectors. Although viral vectors have high transfection efficiency, their shortcomings such as immunogenicity, tumorigenicity, and difficulty in mass…
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Nano Non-Viral Gene Vector
Gene therapy is the introduction of exogenous normal genes or genes with therapeutic effects into target tissues or target cells through vectors or other means, and appropriate expression to treat diseases. The key of gene therapy is to obtain efficient and safe gene delivery vectors. Vectors for gene delivery are generally classified into viral vectors and non-disease vectors. Viral vectors are the most widely used gene vectors, including retroviruses, adenoviruses, adeno-associated viruses and lentiviruses. The biggest advantage of viral vectors is the high transfection rate, but they also have many disadvantages, such as the difficulty of virus preparation, the limited size of loaded foreign DNA, cytotoxicity, immunogenicity, carcinogenicity, etc., and…
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What Are Sterols?
Sterols are essential components of the membranes of all eukaryotic organisms, controlling membrane fluidity and permeability. Sterols are the third class of lipids, which play multiple roles that either individually or collectively influence cell processes, and through charge and structure they are involved in DNA replication, protein translocation, cell recognition, signalling pathways, energetic, signal transduction, and cell trafficking. Sterols regulate biological processes and sustain the domain structure of cell membranes where they are considered as membrane reinforcers . What are the examples of sterols? Cholesterol is the main animal sterol, while β-sitosterol, campesterol, stigmasterol, brassicasterol, avenasterol, and stigmastenol are major plant sterols present in vegetable oils at much higher levels than…
