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 Nano Dressings
Dressing is a kind of medical material that can replace damaged skin or tissue, and can promote wound healing and tissue repair, such as gauze, bandage, sponge. The ideal dressing should have the following functions in application: resist mechanical factors (such as collision), resist pollution and chemical irritation, prevent double infection (such as inflammation), prevent dryness and body fluid loss (electrolyte loss) and prevent heat loss. It can also actively influence the wound healing process through debridement, thereby creating a microenvironment that promotes wound healing.
The special physical and chemical properties of nano-dressing make it compared with traditional dressings. It has many advantages in tissue repair and wound treatment. The specific manifestations are: 1. The fiber diameter is equivalent to that of natural tissue; 2. There are various shapes and a wide range of choices, including nanoparticles, Nanocrystals, nanotubes, nanofibers, nanofilms; 3. Very large specific surface area and good adsorption performance; 4. High mechanical strength and light weight, which can reduce the extrusion of the wound; 5. It can be antibacterial; 6. Can be packaged Embed or load drugs, growth factors, proteins, etc., and play a slow and controlled release effect. The large specific surface area and porous structure can greatly increase the contact area or probability of the nano-dressing with cells or tissues, making it easy for the nano-dressing to enter the wound tissue cells or stay in the cells to regulate biological signals, and promote cell growth, proliferation and differentiation before the process of tissue repair. Nano dressings can also improve the local microenvironment for tissue cell growth, regulate and optimize the formation of extracellular matrix, promote tissue cell regeneration and migration to the wound, and create conditions for tissue remodeling after repair. For more serious tissue defects or damages that cannot be repaired quickly under natural conditions, nano-dressing is applied to the wound to provide a “platform” for the migration and colonization of surrounding normal cells to the defect area. These accelerate the growth of regenerative cells and matrix secretion, to promote the repair of the defect . In the treatment of burns, it is necessary to use as few treatment materials as possible to cover a large area of the wound, protect the skin, and promote wound healing. Nano dressings meet this requirement. Nano dressings also provide support for tissue engineered skin implants. Wounded skin often loses the epidermal layer that constitutes the mechanical barrier. Nanofibers can provide good mechanical support while achieving therapeutic effects. Chemical drugs or biologically active molecules can be embedded in the nano dressing and released to the wound tissue through the pores in the dressing or material erosion. By adjusting the porosity of the nano dressing and the composition and structure of the nanofibers, the release rate of active molecules can be controlled. The slow and controlled release performance can not only avoid the toxicity of local high-concentration drugs, but also ensure the continuous existence and stability of the drug in the damaged area, and further promote the regeneration and repair of damaged cells.
Nano dressings can also carry adult stem cells and progenitor cells, and continue to release “seed cells” to the defect, and make it differentiate into adult cells, accelerating the regeneration and tissue repair of the defect cells. Polymer molecular configurations are diverse (such as linear, star, tree, and hyperbranched), and there are many surface binding sites, which are easy to combine with active molecules. The surface of the polymer is modified by functional groups and can be coupled with antibacterial drugs. It can kill or inhibit various chronic wound-susceptible microorganisms, such as Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli.. Polymer drug conjugates, polymer protein conjugates, polymer micelles, etc., as drug carriers, have been used in tissue repair and wound care. The composition structure of polymer-protein-growth factors can produce good interface interaction with the wound microenvironment, which has important application value in the field of tissue repair. According to the actual needs of wound care and tissue repair, the best effect can be obtained by controlling the physical properties (rheological properties, hydrophilicity), mechanical properties (plasticity) of the nano-dressing, and introducing active ingredients.