本實驗的目的是想證實由Salmonella minnesota(Re595)所分離出來之脂多醣(Lipopolysaccharide)與幾丁聚醣(Chitosan)或是由藥用蕈類-靈芝所萃取而得之幾丁聚醣(SACCHACHITOSAN)之間的交互作用,以不同比例之脂多醣體混合市售不同分子量之幾丁聚醣或是靈芝幾丁聚醣後發現,在SDS-PAGE上以銀染方法得知隨著脂多醣體與幾丁聚醣或是靈芝幾丁聚醣混合比例之增加,導致脂多醣停留於原點而其band消失;另外以Zeta-90測量低、中、高分子量幾丁聚醣與脂多醣體混合後之界面電位發現分別在在8:1、6:1、2:1時界面電位達最高值,在分子篩高效能液相層析儀(SE-HPLC)上證實隨著幾丁聚醣與脂多醣混合後而導致波峰位移,進而推得分子量之改變;在加入幾丁聚醣或是靈芝幾丁聚醣後亦可抑制巨噬細胞RAW264.7受到脂多醣刺激所產生之NO。幾丁聚醣上之正電荷會與脂多醣體結合可提供幾丁質敷料貼覆傷口組織可抑制革藍氏陰性菌生長之合理解釋,並期未來可利用富含幾丁質或幾丁聚醣之生物醫材作為透析敗血症患者血液之新材料。
The purpose of the present study was to elucidate the interaction between lipopolysaccharide (LPS) derived from Salmonella minnesota (Re 595) and chitosan as well as SACCHACHITOSAN, a chitosanous fraction from a medicinal mushroom, Ganoderma. Mixtures in different ratio of LPS and several commercially available chitosans in molecular weights or SACCHACHITOSAN were used for investigation. The spectra of SDS-PAGE showed that LPS was arrested at original position through increase of chitosan or SACCHACHITOSAN ratio that resulted in disappearing of LPS bands visualized by silver staining. The measurement of surface potential for the mixtures by Zeta-90 demonstrated that a highest level occurred at the ratio of 8:1, 6:1, 2:1 and 2:1 for low molecular weight, medium molecular weight, high molecular weight chitosans and SACCHACHITOSAN to LPS, respectively. Similar results were also obtained from the analysis with size-exclusion high performance liquid chromatography (SE-HPLC) that the peak shift of the mixtures of chitosans and LPS was in good agreement to the difference of calculated molecular weight. In vitro test in the culture of RAW264 macrophage cell line revealed that nitrogen oxide (NO) production of LPS was inhibited by the adding chitosans or SACCHACHITOSAN. The binding effect of the positive charged chitosan to LPS could provide a good explanation to the inhibition effect of gram-negative bacteria growth in the tissue of the wound when chitin material was applied as wound dressing. It might be also useful for the patients of sepsis by a possible treatment of dialyzing peripheral blood through a chitosan or chitin rich biomaterials.