Abstract: BACKGROUND: At present, cotton lint and its modified products have been widely concerned in cleaning water or oil pollution, but the preparation of cotton lint for hemostatic gauze has not been reported. 
OBJECTIVE: To prepare a kind of carboxymethylated cotton linters hemostatic gauze by modifying cotton linters gauze and characterize it.
METHODS:  Carboxymethylated cotton linters cotton gauze was prepared by chemical modification. Infrared spectrometer, scanning electron microscope and X-ray diffractometer were used to characterize the morphology and structure of cotton linter gauze group (raw material), carboxymethylated cotton linter hemostatic gauze (experimental group) and absorbable hemostatic gauze (control group). The physical and chemical indexes were measured by water absorption, mechanical properties, gelation rate and solubility. The hemostatic performance was tested by measuring whole blood coagulation time. At last, the cytocompatibility of gauze in the experimental group was evaluated by cytotoxicity test in vitro.  
RESULTS AND CONCLUSION: (1) The result of infrared spectrum showed that carboxymethylation occurred in the gauze from experimental group, The hydrophilic carboxymethyl group was introduced into the fiber structure. X-ray diffraction results showed that compared with the raw material group, the crystal phase of the experimental and the control groups was incomplete with the crystallinity decreased. (2) Scanning electron microscope result showed that the fibers of the raw material group were straight and tightly arranged. In the experimental group, the fiber braiding mode was not changed, but the arrangement was loose, the fiber diameter was increased, and the surface roughness was increased. In the control group, the fiber had a unique weaving mode; the fiber surface was long and thin, smooth and the texture was clear. (3) There was no significant difference in porosity among the three groups (P > 0.05). The water absorption rate of the experimental group was higher than that of the raw material group (P < 0.05) and lower than that of the control group (P < 0.05). (4) Both the experimental group and the control group formed gel within 30 seconds after water absorption, and completely dissolved within 1 hour. (5) The tensile strength of the experimental group was lower than that of the raw material group (P < 0.05), but there was no significant difference between the experimental and the control groups (P > 0.05). The fracture elongation of the experimental group was higher than that of the raw material group (P < 0.05) and lower than that of the control group (P < 0.05). (6) The blood coagulation time in the experimental group was shorter than that in the raw material group (P < 0.05), while it did not differ from the control group significantly (P > 0.05), indicating that the gauze in the experimental group had good cytocompatibility. (7) The results suggested that carboxymethylated cotton linters hemostatic gauze presented good physical and chemical properties, hemostatic properties and cellular compatibility.

Key words: material, cotton lintes gauze, carboxymethylated, physical and chemical properties, structure, hemostatic performance, cytocompatibility