CN-121971678-A - Multilayer composite dressing with interlayer continuous antibacterial network and preparation method thereof

CN121971678ACN 121971678 ACN121971678 ACN 121971678ACN-121971678-A

Abstract

The invention relates to the technical field of medical equipment, in particular to a multilayer composite dressing with an interlayer continuous antibacterial network and a preparation method thereof. The dressing comprises at least two polymer substrate layers, metal antibacterial layers and connecting structures, wherein the polymer substrate layers are provided with through pore networks, the metal antibacterial layers are coated on the skeleton surface of each polymer substrate layer to form a metal skeleton, the connecting structures are arranged between the adjacent polymer substrate layers and are distributed in discrete point shapes and used for fixedly connecting the adjacent polymer substrate layers, and the metal skeletons of the adjacent polymer substrate layers form physical contact at interlayer interfaces to form an electrical path of the interlayer metal antibacterial layers. The dressing of the invention constructs a three-dimensional continuous electrochemical antibacterial network in the full thickness direction, and effectively solves the industrial problem of internal biomembrane breeding and drainage blockage in deep wound care.

Inventors

HU ZHENGYU
SHI RUI
ZENG XIANQUAN
ZENG DA
CHEN YANWEN
FANG MINJIE

Assignees

大博医疗科技股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260409

Claims (10)

1. A multi-layer composite dressing having an interlaminar continuous antimicrobial network, comprising: at least two polymeric substrate layers having a network of through pores; A metal antibacterial layer coated on the surface of the skeleton of each polymer substrate layer to form a metalized skeleton, and A connection structure disposed between adjacent ones of the polymeric substrate layers; The connecting structures are distributed in discrete points between the adjacent polymer substrate layers and are used for fixedly connecting the adjacent polymer substrate layers; The metallized backbones of adjacent polymer substrate layers form physical contact at the inter-layer interface to form an electrical pathway for the inter-layer metallic antimicrobial layer.
2. The multi-layered composite dressing with an interlaminar continuous antibacterial network according to claim 1, wherein the multi-layered composite dressing has a pore size gradient structure in a thickness direction, wherein a pore size of the polymer base material layer on a side close to the wound surface is larger than a pore size of the polymer base material layer on a side far from the wound surface.
3. The multi-layer composite dressing having an interlaminar continuous antibacterial network according to claim 2, wherein the pore size of the polymer base material layer on the side close to the wound surface is 1000 μm to 1500 μm, and the pore size of the polymer base material layer on the side far from the wound surface is 500 μm to 1000 μm.
4. The multilayer composite dressing with an interlaminar continuous antimicrobial network of claim 1, wherein the metallic antimicrobial layer is a pure silver layer having a thickness of 500nm to 2000nm.
5. The multilayer composite dressing with an interlaminar continuous antibacterial network according to claim 1, wherein the metallic antibacterial layer is a tantalum silver composite coating or a tantalum silver alloy coating, the mass percentage of silver in the coating is 20-50 wt%, and the thickness of the coating is 100-500 nm.
6. The multilayer composite dressing with an interlaminar continuous antimicrobial network of claim 1, wherein the connection structure is a nonwoven structured hot melt web film having a grammage of 10g/m 2 to 25g/m 2 .
7. The multilayer composite dressing with an interlaminar continuous antimicrobial network of claim 6, wherein the melting point of the hot melt web film is below the softening temperature of the polymeric substrate layer.
8. The multilayer composite dressing with an interlaminar continuous antimicrobial network of claim 7, wherein the material of the hot melt web film is selected from one or more of copolyamide, copolyester, thermoplastic polyurethane, or ethylene-vinyl acetate copolymer.
9. A method of preparing a multilayer composite dressing having an interlaminar continuous antimicrobial network according to any of claims 1 to 8, comprising the steps of: providing at least two polymeric substrate layers, the polymeric substrate layers having a network of pores therethrough; forming a metal antibacterial layer on the surface of the skeleton of each polymer substrate layer to obtain a metalized skeleton; A connecting structure is arranged between adjacent metallized frameworks to form a laminated body; and carrying out hot pressing treatment on the laminated body, melting the connecting structure, forming discrete point-shaped distribution between the adjacent polymer substrate layers, fixedly connecting the adjacent polymer substrate layers, and forming physical contact between the metalized frameworks of the adjacent polymer substrate layers at the interlayer interface to form an electrical path of the interlayer metal antibacterial layer.
10. The method of claim 9, wherein the heat press treatment is at a temperature above the melting point of the connecting structure and below the softening temperature of the polymer substrate layer.

Description

Multilayer composite dressing with interlayer continuous antibacterial network and preparation method thereof Technical Field The invention relates to the technical field of medical equipment, in particular to a multilayer composite dressing with an interlayer continuous antibacterial network and a preparation method thereof. Background Polymer foam materials, in particular Polyurethane (PU) foam materials, are widely used in medical wound dressings, in particular as filling materials for negative pressure drainage (NPWT) or for high exudation wounds (e.g. burns, pressure sores), due to their good biocompatibility, high porosity and excellent exudate management. To prevent wound infection, imparting antimicrobial properties to polymeric foam dressings has been a research hotspot and industry pain in the art. Currently, the main technical approaches to imparting antimicrobial properties to polymeric foam dressings include the following: Firstly, the mixed foaming method is to directly blend an antibacterial agent (such as silver powder, silver salt or other metal particles) into a polymer raw material for physical mixing, and then foam molding. The method is simple to operate, but has inherent defects that most of the antibacterial agent is wrapped in a polymer matrix and cannot be effectively contacted with wound exudates, so that expensive antibacterial materials are wasted, and meanwhile, when the filling quantity of the antibacterial agent is increased to ensure enough antibacterial effect, the pore size structure, the porosity and the mechanical property of foam can be obviously changed, and the liquid absorbing capacity and the use comfort of the dressing are affected. Secondly, the antibacterial coating is loaded on the surface and the inner pore wall of the formed foam by a dipping reduction or spraying method. The method realizes the distribution of the antibacterial components in the three-dimensional structure of the foam to a certain extent, but for the dressing with larger thickness, the coating load rate deep inside the foam is often lower due to the limitation of liquid permeation and mass transfer resistance. When large amounts of exudates are absorbed and retained inside the foam, bacteria tend to grow and form biofilms in the deep layers of the foam, resulting in a risk of "back-infection" due to lack of sufficient antimicrobial components inside. In addition, improper reduction process or too thick coating can also cause the blockage of foam pore channels with smaller pore diameters, thereby creating conditions for bacterial growth. Thirdly, a multilayer compounding process. To meet clinical demands for dressing size, gradient function or composite function, multiple layers of foam are often bonded. However, the traditional glue bonding process can form a compact continuous glue film between layers to block pore networks, so that the vertical liquid absorption speed and the water vapor transmittance of the dressing are seriously reduced, and the flame compounding process is easy to destroy the prepared functional coating due to high temperature, so that the overall performance of the dressing is influenced. Therefore, there is a need to develop a novel dressing structure that can achieve all-thickness-direction "bulk phase antibacterial" while maintaining the original permeability of foam, and has long-term stability. Disclosure of Invention In order to solve the defects in the prior art, the invention provides a multilayer composite dressing with an interlayer continuous antibacterial network and a preparation method thereof. A first aspect of the present invention provides a multi-layer composite dressing having an interlaminar continuous antimicrobial network, comprising: at least two polymeric substrate layers having a network of through pores; A metal antibacterial layer coated on the surface of the skeleton of each polymer substrate layer to form a metalized skeleton, and A connection structure disposed between adjacent ones of the polymeric substrate layers; The connecting structures are distributed in discrete points between the adjacent polymer substrate layers and are used for fixedly connecting the adjacent polymer substrate layers; The metallized backbones of adjacent polymer substrate layers form physical contact at the inter-layer interface to form an electrical pathway for the inter-layer metallic antimicrobial layer. In one embodiment of the present invention, the multi-layered composite dressing has a pore size gradient structure in the thickness direction, wherein the pore size of the polymer substrate layer on the side near the wound surface is larger than the pore size of the polymer substrate layer on the side far from the wound surface. In one embodiment of the invention, the pore size of the polymer substrate layer on the side near the wound surface is 1000 μm to 1500 μm, and the pore size of the polymer substrate layer on the side far from the wound surface is 500 μ