Research On Preparation And Characteristics Of Antibacterial Bacterial Cellulose/nonwoven For Medical Dressing

Requirements for ideal wound dressing should be satisfied as follows. Ideal wound dressing is ought to provide the moist environment for wound healing,effectively prevent microbial invasion, reduce infection rate, avoid the secondary trauma brought by changing dressings, reduce pain,ease of use and etc.When bacterial cellulose(BC) is used as medical dressing, it is difficult to spread on the wound. And there are also some shortcomings for nonwoven(Non) medical dressing, such as poor fluid retention performance and poor biocompatibility. Therefore, in this paper, we prepared bacterial cellulose/nonwoven composite(BC/N) by biological composition method to improve their performances. In order to prepare excellent antimicrobial medical dressing, we also prepared the BC/N materials containing silver( Ag) and carboxymethyl chitosan(CMCS), and studied the antibacterial and biocompatibility.First of all, we prepared BC/N composites with different BC content by biological composition method. Macroscopic morphology showed the significant improvement of spreading problem. FTIR and SEM results showed BC and Non achieved good physical composition. We also observed the improvement of the moisture content and moisturizing properties of Non, and the largest moisture content of the Non could be increased three times, water loss rate could be reduced by 32%. The tensile strength and elongation at break of the composite were higher than Non and BC, especially the tensile strength of the composite which increased more than 10 MPa than BC. And Ag was loaded on BC/N by in situ composite, antimicrobial experiments showed excellent antibacterial effects. But when directly contacted with L929 cells, they showed some cytotoxicity.Furthermore, in order to eliminate the adverse effects of inorganic Ag, we also prepared BC/N-CMCS composite by solution impregnation. FTIR, SEM, elemental analysis results showed that CMCS successfully incorporated the network of BC/N composite, and the largest content of CMCS achieved 32.22%. The moisture content and moisturizing properties of the BC/N composite were further improved. Largest moisture content increased 400% and water loss rate reduced by 20%. Although the tensile strength of BC/N-CMCS was slightly lower than that of BC/N, its elongation at break was slightly higher. And compared with Non and BC, BC/N-CMCS composite still exhibited good mechanical properties. BC/N-CMCS composite showed good antibacterial effect with increasing CMCS content, and the antibacterial rate of BC/N-4C reached more than 99% after 3h cultivating with the bacteria. The cell experiment of BC/N and BC/N-CMCS showed that composites were safe, non-toxic, and the cells could achieve good adhesion and proliferation on the surface. Therefore, the BC/N-CMCS composite was expected to be widely used in the field of medical dressing.