Antimicrobial Dressing Containing Silver PLGA Preparation And Toxicity Evaluation

Trauma, burns, and surgery often result in skin damage. The reasons that include wound infection, secondary damage or can not maintain a moist wound surface often lead to delayed wound healing. Traditional dressing has the following advantages: a strong absorptive capacity, low cost and readily available raw materials, production of simple and reusable.But its shortcomings are particularly prominent. materials science produced, which is based medicine and materials science-based. From the basic properties of the material to the evaluation and application of toxic materials, it is proposed that the ideal dressing should have the following features:a.to maintain the temperature of the wound surface;b. to control and respiratory exudate;c. enough to provide a bacterial barrier, creating a favorable environment for tissue growth, promote tissue growth;d. to provide thermal isolation and conductivity;e. easy to use, easy to get;f. Non-toxic, harmless and without stimulation;g. enable the smooth transmission of gas and steam;h. has good mechanical properties etc. So far, no one kind of dressing to achieve the desired performance requirements. Therefore, the development of antibacterial properties of biodegradable artificial dressing realistic significance. Poly (lactic acid - glycolic acid) is non-toxic and harmless. Because of excellent adjustable degradability and good mechanical properties, it has been widely used as medical materials in all areas of clinical treatment. Dimethyl sulfoxide is a natural organic sulfur compounds and was found to exist in a variety of natural foods such as fruits, vegetables, and grains. In human skin, hair, nails, bones, muscles and other organs of the various organizations is also important to detect the presence of MSM. It is considered essential human collagen material, and more and more used as a dietary supplement by humans. It is important to human health. Silver is recognized as a broad-spectrum antimicrobial properties of metals, can inhibit bacteria and fungi reproduction. Nano-silver is a kind of nano-particles, has a unique microstructure, surface area greatly, quantum effect, small size effect and is different from conventional materials, light, electricity, heat and more stable catalysts and other physical and chemical properties. Therefore, traditional inorganic antibacterial agents can not compare the antibacterial effect and long-lasting. In this study,MSM and nano-silver is added in biodegradable polymer PLGA. Prepared by electrostatic spinning has antibacterial properties of biodegradable artificial dressing.By scanning electron microscopy the surface structure of fibers can be seen: fibers cross the grid-like structure, adhesion with each other ;with the increase of nano-silver content, fiber diameter gradually becomes larger, growing degree of crosslinking. Surface element analysis and mechanical testing prove that nano-silver uniformly dispersed to fiber mat and the rising degree of crosslinking resulted in fiber mechanical strength gradually. Experimental results show that the absorbent fiber mat has some water absorption. Toxicity evaluation included material extract cytotoxicity test, acute systemic toxicity, skin irritation test and antimicrobial research, the results show that when the mass fraction of nano-silver below 1%, the fiber material has good biocompatibility, cell proliferation and contribute to growth, no cell toxicity, no skin irritation, no acute systemic toxicity.From Oscillation experiments and inhibition zone shaking bacteria we can get the following conclusions: nano-silver antimicrobial dressings have antimicrobial activity and the inhibitory effect on E. coli is higher than Staphylococcus aureus;With the increasing content of nano-silver antimicrobial capacity is gradually increased. When nano-silver accounted for the mass fraction of PLGA 10%, it has the strongest inhibition. At this point, its inhibitory rate of E. coli up to 99.3% inhibition rate of S. aureus up to 98.3%.In summary, through characterization of the fiber structure and toxicity evaluation we can get the following conclusions. Preparation of the fiber in this study is non-toxic and non-irritating.They have good mechanical properties,good mechanical properties, a certain absorption capacity, good inhibitory effect and consistent with the evaluation criteria of biological materials. They have a wide range of applications, and provide enough theoretical basis of artificial biodegradable antimicrobial dressings development and industrialization.