Abstract: An antibacterial dressing for promoting scarless wound healing and a method for preparing the same provided. The dressing consists of 0.05-0.1 part by weight of hyperbranched polylysine anti-scar compound, 0.1-2.0 parts by weight of carbomer, 1-10 parts by weight of a thickener, 2-12 parts by weight of a humectant, 60-90 parts by weight of water and 1-15 parts by weight of a plant extract. The hyperbranched polylysine and the anti-scar drug are grafted and synthesized into a new compound, so that the antibacterial activity of the hyperbranched polylysine and the ability of the anti-scar drug to inhibit the scar formation of the wound are retained; meanwhile, a film with good air permeability and moisture retention can be formed on the skin surface through the film forming agent, so that the wound surface is kept in a moist environment, which is beneficial to wound healing and does not generate scars.

Abstract: A tough antibacterial hydrogel dressing and a preparation method thereof provided. The hydrogel dressing is gelatinized based on hydrogen bonding of gelatinizing skeleton such as polyvinyl alcohol, gelatin, collagen, etc. Before gelatinizing, hyperbranched polylysine is mixed, and after gelatinizing, the mechanical properties are enhanced by soaking in an ionic solution. Physical gelatinizing by hydrogen bonding can avoid the toxicity problem caused by residual crosslinking agent in the chemical crosslinking method, and the shortcoming of poor mechanical properties of hydrogel obtained by physical crosslinking method is overcome by Hoffmeister effect salting-out. The hydrogel dressing prepared has good tensile and compressive properties and antibacterial properties. The hydrogel dressing provided is suitable for various skin wounds, and has the advantages of simple preparation method, high repeatability and low cost, and is expected to be widely used in the field of antibacterial skin dressings.

Abstract: A suture-free coagulation-assisted fixed cardiac patch and fabrication method thereof are provided. The cardiac patch includes a polymeric procoagulant base and a barbed microneedle fixed on the polymeric procoagulant base, and a side surface of the polymeric procoagulant base with the microneedle has a microporous structure which does not penetrate the solid base of the polymer; an included angle ? between the microneedle and the plane where the polymeric procoagulant base located is 60-90°, and the microneedles are evenly distributed on the polymeric procoagulant base at a density of 5-50 threads/cm2; the barbs are located on the curved surface of the microneedle and are inclined toward the polymeric procoagulant base. The fabrication method includes using a mold pore-forming, a porogen pore-forming, or a thermally induced phase separation pore-forming, and combining the barbed microneedle while forming the microporous structure to obtain a suture-free coagulation-assisted fixed cardiac patch.

Abstract: The present application belongs to the technical field of polymer materials, and hyperbranched polylysine powder with a low polydispersity index and a production method thereof provided. The present application adopts a thermal initiation polymerization method, Compared with the traditional method, the production method of hyperbranched polylysine has the advantages of no additional steps of introducing and removing amino protecting groups, no need of activating carboxyl groups, easy purification of products, short production period, controllable molecular weight of products and low polydispersity index (1.01-1.2), and is suitable for industrial production of hyperbranched polylysine materials, especially medical-grade hyperbranched polylysine materials.

Abstract: The present application belongs to the technical field of polymer materials, and hyperbranched polylysine powder with a low polydispersity index and a production method thereof provided. The present application adopts a thermal initiation polymerization method, Compared with the traditional method, the production method of hyperbranched polylysine has the advantages of no additional steps of introducing and removing amino protecting groups, no need of activating carboxyl groups, easy purification of products, short production period, controllable molecular weight of products and low polydispersity index (1.01-1.2), and is suitable for industrial production of hyperbranched polylysine materials, especially medical-grade hyperbranched polylysine materials.

Abstract: A two-layer gradient coating article is provided that is operable to cause selective adhesion and directional migration of endothelial cells. The first layer includes cell-resisting polymers that repels cells, the second layer includes one layer of peptides that has affinity to and binds specifically to endothelial cells. Furthermore, the peptides are distributed in a gradient, in which attached ECs migrate towards the direction of increased concentration, thus enriching the ECs to a desired locus. The combination of a cell-repelling layer and a graded affinity peptide produces a unique result of selective adhesion, directional migration, thus local enrichment of endothelial cells. A method for using such gradient coating article and its potential use in treating cardiovascular diseases are also provided. The invention provides an inexpensive, stable and effective means for attracting ECs to desirable locations.

Abstract: A two-layer gradient coating article is provided that is operable to cause selective adhesion and directional migration of endothelial cells. The first layer includes cell-resisting polymers that repels cells, the second layer includes one layer of peptides that has affinity to and binds specifically to endothelial cells. Furthermore, the peptides are distributed in a gradient in which attached ECs migrate towards the direction of increased concentration, thus enriching the ECs to a desired locus. The combination of a cell-repelling layer and a graded affinity peptide produces a unique result of selective adhesion, directional migration, thus local enrichment of endothelial cells. A method for using such gradient coating article and its potential use in treating cardiovascular diseases are also provided. The invention provides an inexpensive, stable and effective means for attracting ECs to desirable locations.

Abstract: Method of layer-by-layer (LbL) assembly of oppositely charged polyelectrolytes was applied to coat fluorescein particles. These particles with a size of 4-9 &mgr;m were prepared by precipitation of fluorescein at pH 2. Polysterensulfonate (PSS) and polyallylamine (PAH) were used to compose the polyelectrolyte shell on the fluorescein core. The release of fluorescein molecules through the polyelectrolyte shell core dissolution was monitored at pH 8 by increasing fluorescence intensity. The number of polyelectrolyte layers sufficient to sustain fluorescence release was found to be 8-10. Sequentially adsorbed layers prolong core dissolution time for minutes. The permeability of polyelectrolyte multilayers of the thickness of 20 nm is about 10−8 m/s. Mechanism of fluorescence diffusion and osmotically supported release is under discussion. The features of release profile and possible applications or LbL method for shell formation in order to control release properties for entrapped materials are outlined.