| The 3D printing world has recently shown more and more interesting things, and potential applications include electronic devices and cartilage substitutes.  Last summer, a group of researchers at the University of Manitoba created a new, electrically conductive 3D printing method for self-healing hydrogel materials, which has mechanical stability and is both physical and chemical. A schematic diagram of an injectable ' A + B ' hydrogel using a double-cylinder syringe, which is crosslinked during or after the injection. 3D hydrogels are hydrophilic polymer networks that are cross-linked by chemical covalent bonds, physical interactions, or a combination of both. Because of the crosslinking between the polymer chains and their hydrophilicity, the hydrogel can actually swell to 100 times times the dry matter, or even 1000 times times, without dissolving in the water. Although hydrogel used to be pre-prepared and implanted in the body's target area during surgery, it is now easy to inject from a syringe with a fine needle, making the material ideal for biomedical applications. According to Liyang Shi, of the University of Uppsala in Switzerland, a paper entitled "Injectable composite hydrogel for metal ligand assembly based on biomedical applications", injectable hydrogels are useful in the development of minimally invasive surgery because they ' avoid injury to surrounding tissue ' during implant surgery ' And it is easy to fill in the defects of the in-situ complex shapes. In addition, 3D printing injectable hydrogels are not difficult, so they can be produced by automatically extruding from the syringe and programming the movement in the CAD file to form a more advanced custom-shaped hydrogel. This paper presents a summary of various biomedical applications based on HA-BP hydrogel and hydrogel. Derivative ha-bp (i), HA-BP (ii) and HA-BP (iii) represent three different types of connections between the BP part and the HA skeleton. Shi uses hyaluronic acid (HA) as a polymer because of its biocompatibility and biodegradability.  First, a double phosphonic acid salt (BP) as chelating (heterocyclic ring compound) ligand was modified. A hydrogel precursor consisting of a polymer chain containing a UV cross-linked group is discharged from the syringe in a liquid and then crosslinked in the polymerization defect area using light. The hydrogels produced during the experiment ' exhibit dynamic characteristics ' such as shear thinning and self-healing properties.   Shi will apply four hydrogels based on HA-BP to different biomedical applications, including 3D printing, wound healing, bone regeneration and control delivery of anticancer drugs. In a word, this paper puts forward a chemical strategy of metal ligand ligand, in order to establish an injectable hydrogel with dynamic cross-linking, so as to produce injection behavior unrelated to time. |
