Sponge-type alginate ag dressings
Alginate ag dressings are usually prepared using freeze-drying methods, which produce sponges with a porous structure that can absorb a large amount of wound exudate, keeping the wound moist. The sponge can support the proliferation of keratinocytes and gingival fibroblasts. This sponge can be used as temporary medical dressing supplies that is changed daily. It has an asymmetric structure consisting of a surface layer and a sponge-like porous layer, with a dense outer layer that helps prevent bacterial infection and wound dehydration. The pore size range of the sponge is 100-500μm, with good tear strength, making it suitable for covering surgical wounds in the oral cavity. Alginate ag dressings made from sodium alginate using a solution of calcium chloride/glycerol/alcohol for coagulation and freeze-drying technology have a smooth and crack-free surface, a clean white color, and good elasticity and flexibility.
The surface and interior of alginate ag dressings have a uniform and interconnected pore structure, with pore sizes ranging from 100-500μm, a porosity of 84.37%, an air permeability of 44.75%, and a liquid-absorbing capacity of 30.48g/g and 5.13g/g for absorbing and retaining wound exudate, respectively. It can quickly absorb a large amount of wound exudate, keep the wound dry, and provide a moist healing environment for the wound, accelerating its healing. The stretching strength of the alginate ag dressing is 0.21MPa, and the initial modulus is 7.72N/mm. Its mechanical properties are excellent compared to non-woven medical dressings, and its physical properties such as thickness and apparent density are similar to those of non-woven medical dressings. The performance of the alginate ag dressing is superior or comparable to that of non-woven medical dressings and can be used to treat various types of skin injuries, such as surgical wounds, burns, and scalds, with a promising future application.
Hydrogel-type medical dressing supplies made from alginate
Hydrogel is a gel-like substance that can swell in water but does not dissolve in water. It has good water absorption capacity (up to several thousand times its dry weight) and can absorb and prevent the massive loss of tissue fluid, keeping the wound moist. In addition, the medical dressing supplies have the following advantages:
Good biocompatibility, rapid hemostasis, and pain relief;
Oxygen permeable, transparent appearance, and easy to observe wound repair;
Physical properties similar to soft tissues, closely adhering to the wound to isolate bacteria and not sticking to the wound, which does not cause secondary damage to the wound when changing dressings;
Medical dressing suppliers can carry and slowly release various antibacterial drugs. Depending on the hydration status of the tissue, hydrogel can absorb or provide water to the wound environment. Hydrogel leaves no residue, is flexible, and improves the formation of epithelium at the wound site.
In cell toxicity tests, ACF-HS exhibited no toxicity to human skin fibroblasts and skin microvascular endothelial cells. The use of ACF-HS in healing damaged wounds significantly improves granulation tissue and capillary formation. This may be due to ACF-HS absorbing some substances related to cell proliferation, migration, and angiogenesis from wound plasma or exudate, such as growth factors and cytokines. Therefore, this composite hydrogel has potential in repairing and healing damaged wounds.