GLASS COMPOSITION FOR WOUND CARE, WOUND COVERING MATERIAL, AND METHOD FOR PRODUCING SAME

Abstract

Provided are: a glass composition for wound care, which promotes a wound healing process by providing a moist environment and nutrients necessary for growth of epidermal cells, and which has bactericidal properties for preventing critical fixing of bacteria to a wound surface and infection with bacteria; and a wound covering material that uses the glass composition. The glass composition contains, by mass % in terms of oxides, 5 to 70% of SiO.sub.2, 0 to 10% of Al.sub.2O.sub.3, 5 to 40.0% of B.sub.2O.sub.3, and 1 to 50% of CaO.

Claims

6. The glass composition for wound care according to claim 1, wherein a temperature corresponding to a viscosity of 10.sup.1.0 dPa.Math.s is 1500° C. or lower.

7. A wound covering material which is a cottony body or a nonwoven fabric comprising a glass composition of claim 1.

8. The wound covering material according to claim 7, wherein an average fiber diameter of glass fibers constituting the cottony body or the nonwoven fabric is 100 nm to 10 μm.

9. The wound covering material according to claim 7, wherein glass beads are mixed in the cottony body or in the nonwoven fabric, and the amount of glass beads mixed with is, based on mass %, 50% or less of the entire cottony body or the entire nonwoven fabric.

10. The wound covering material according to claim 9, wherein an average diameter of the glass beads is 500 μm or less.

11. A method for producing a wound covering material, comprising: melting a starting material batch prepared to give a glass composition of claim 1 in a glass melting furnace; and continuously ejecting the molten glass through a glass ejecting nozzle while applying an air jet to an area around the glass ejecting nozzle to make the glass into a cottony form.

12. The method for producing a wound covering material according to claim 11, further comprising forming a nonwoven fabric by compressing the glass shaped in a cottony form.

Description

EXAMPLES

[0061] The present invention is described in detail with reference to Examples hereinunder.

[0062] Tables 1 to 5 show Examples of the present invention (Sample Nos. 1 to 17, 21 to 25) and Comparative Examples (Sample Nos. 18 to 20).

TABLE-US-00001 TABLE 1 Sample No. 1 2 3 4 5 Glass SiO.sub.2 15.3 32.30 20.58 44.25 32.92 Composition Al.sub.2O.sub.3 (mass %) B.sub.2O.sub.3 24.6 27.28 37.94 7.35 17.94 MgO 4.8 4.33 4.45 4.30 4.42 CaO 36.9 17.25 17.70 24.88 25.52 Na.sub.2O 5.6 5.13 5.26 5.10 5.23 K.sub.2O 11.4 10.35 10.62 10.28 10.55 P.sub.2O.sub.5 1.4 3.36 3.45 3.34 3.43 Na.sub.2O + K.sub.2O 17.0 15.48 15.88 15.37 15.78 Molar Ratio of Boron to 2.8 1.5 3.2 0.3 0.9 Silicon in Glass Composition (B/Si) B Concentration in 14.5 10.3 12.3 1.6 3.4 Simulated body fluid (mM) Ca Concentration in 12.6 5.2 4.8 5.2 4.8 Simulated body fluid (mM) Spinning Temperature (° C.) 891 1084 991 1260 1067 Liquidus viscosity (dPa .Math. s) 10.sup.0.4 10.sup.1.0 10.sup.0.8 10.sup.1.7 10.sup.1.7 Average Fiber Diameter (μm) 0.6 Not measured Not measured 1.0 Not measured

TABLE-US-00002 TABLE 2 Sample No. 6 7 8 9 10 Glass SiO.sub.2 20.99 8.39 33.57 21.41 63.01 Composition Al.sub.2O.sub.3 (mass %) B.sub.2O.sub.3 28.56 39.76 8.22 18.79 7.22 MgO 4.54 4.66 4.50 4.63 3.95 CaO 26.21 26.93 34.13 35.06 8.63 Na.sub.2O 5.37 5.52 5.33 5.48 4.68 K.sub.2O 10.83 11.13 10.75 11.05 9.44 P.sub.2O.sub.5 3.52 3.61 3.49 3.59 3.07 Na.sub.2O + K.sub.2O 16.20 16.64 16.09 16.53 14.12 Molar Ratio of Boron to 2.4 8.2 0.4 1.5 0.2 Silicon in Glass Composition (B/Si) B Concentration in 9.3 21.5 0.8 3.2 Not Simulated body fluid (mM) measured Ca Concentration in 6.1 8.1 4.7 5.9 Not Simulated body fluid (mM) measured Spinning Temperature (C.) 955 879 1107 954 Not measured Liquidus viscosity (dPa .Math. s) 10.sup.0.7 10.sup.0.9 10.sup.0.9 10.sup.0.8 Not measured Average Fiber Diameter Not Not Not Not Not (μm) measured measured measured measured measured

TABLE-US-00003 TABLE 3 Sample No. 11 12 13 14 15 Glass SiO.sub.2 53.07 42.65 31.70 61.94 52.15 Composition Al.sub.2O.sub.3 (mass %) B.sub.2O.sub.3 16.44 26.12 36.29 15.79 25.05 MgO 4.05 4.15 4.25 3.89 3.98 CaO 8.83 9.05 9.28 1.49 1.52 Na.sub.2O 4.79 4.91 5.03 4.60 4.71 K.sub.2O 9.67 9.91 10.15 9.28 9.50 P.sub.2O.sub.5 3.14 3.22 3.30 3.01 3.09 Na.sub.2O + K.sub.2O 14.46 14.82 15.19 13.88 14.21 Molar Ratio of Boron to 0.5 1.1 2.0 0.4 0.8 Silicon in Glass Composition (B/Si) B Concentration in Not Not Not Not Not Simulated body fluid (mM) measured measured measured measured measured Ca Concentration in Not Not Not Not Not Simulated body fluid (mM) measured measured measured measured measured Spinning Temperature (° C.) Not Not Not Not Not measured measured measured measured measured Liquidus viscosity (dPa .Math. s) Not Not Not Not Not measured measured measured measured measured Average Fiber Diameter Not Not Not Not Not (μm) measured measured measured measured measured

TABLE-US-00004 TABLE 4 Sample No. 16 17 18 19 20 Glass SiO.sub.2 41.89 31.45 29.3 45.1 Composition Al.sub.2O.sub.3 13.8 13.8 (mass %) B.sub.2O.sub.3 34.77 20.14 56.60 40.3 8.2 MgO 4.07 5.07 4.60 2.1 2.1 CaO 1.56 22.32 18.50 13.5 23.6 Na.sub.2O 4.82 5.55 5.50 0.6 6.8 K.sub.2O 9.73 12.27 11.10 0.2 0.2 P.sub.2O.sub.5 3.16 3.20 3.70 0.2 0.2 Na.sub.2O + K.sub.2O 14.55 17.50 16.60 0.8 7.0 Molar Ratio of Boron to 1.4 1.1 — 2.4 0.3 Silicon in Glass Composition (B/Si) B Concentration in Not measured 6.1 61.1 5.8 0.01 Simulated body fluid (mM) Ca Concentration in Not measured 5.1 10.4 3.6 2.6 Simulated body fluid (mM) Spinning Temperature (° C.) Not measured 1106 965 1360 1463 Liquidus viscosity (dPa .Math. s) Not measured 10.sup.1.4 10.sup.0.4 Not Not measured measured Average Fiber Diameter (μm) Not measured 2.0 1.1 1.5 1.2

TABLE-US-00005 TABLE 5 Sample No. 21 22 23 24 25 Glass SiO.sub.2 14.77 21.20 14.92 15.08 14.96 Composition Al.sub.2O.sub.3 (mass %) B.sub.2O.sub.3 34.08 23.72 29.24 24.29 24.11 MgO 4.60 4.58 4.64 4.69 2.77 CaO 26.56 30.59 31.01 35.55 37.92 Na.sub.2O 5.44 5.42 5.50 5.55 5.51 K.sub.2O 10.98 10.94 11.09 11.20 11.12 P.sub.2O.sub.5 3.56 3.55 3.60 3.64 3.61 Na.sub.2O + K.sub.2O 16.42 16.36 16.58 16.75 16.63 Molar Ratio of Boron to 4.0 1.9 3.4 2.8 2.8 Silicon in Glass Composition (B/Si) B Concentration in 18.2 9.8 15.1 13.4 13.7 Simulated body fluid (mM) Ca Concentration in 6.7 6.5 8.1 10.3 11.2 Simulated body fluid (mM) Spinning Temperature (° C.) 914 946 927 917 931 Liquidus viscosity (dPa .Math. s) 10.sup.0.6 10.sup.1.0 10.sup.0.5 10.sup.0.6 10.sup.0.4 Average Fiber Diameter Not Not Not 0.7 Not (μm) measured measured measured measured

[0063] The samples in Tables were prepared as follows.

[0064] First, various glass materials such as natural materials, chemical materials and others were weighed and mixed to have the glass composition shown in each Table, thereby preparing a glass batch. Next, the glass batch was put into a platinum-rhodium alloy-made crucible, and heated at 1200 to 1550° C. for 4 hours in an indirect-heating electric furnace to give molten glass. For producing homogeneous molten metal, the molten glass was stirred plural times using a heat-resistant stirring rod at the time of heating. Subsequently, the resultant molten glass was cast into a heat-resistant mold, and left cooled in air to give a massive glass sample. Each resultant sample was tested in an elution test to measure the B concentration and the Ca concentration in a simulated body fluid. In addition, the spinning temperature and the liquidus temperature were measured.

[0065] Further, the massive glass sample was put into a noble metal-made pot equipped with a glass ejecting nozzle, and the glass sample was remelted by electrical heating. Subsequently, a high-speed air jet was applied to the glass flowing down from the ejecting nozzle so as to stretch and fiberize the molten glass thereby giving a cottony body. The average fiber diameter of the glass fibers constituting the thus-obtained cottony body was measured.

[0066] The elution test for measurement is as follows: First, the massive glass sample was ground, and the resultant grass fraction having a particle diameter of 300 to 500 μm was accurately weighed by a weight fraction of a density×0.256, and subsequently, 60 ml of a simulated body fluid was put into a polypropylene container (PP container) having a volume of 100 ml, then the glass sample was dipped therein and subjected to an elution test under a condition of 37° C. for 2 days. On this occasion, the sample was stirred once/day. For the stirring, the PP container was shaken a few times by hand. After the elution test, the test solution was filtered, and using ICP-OES, the B concentration and the Ca concentration in the eluate were quantified.

[0067] The simulated body fluid was prepared as follows: First, a beaker filled with 100 ml of distilled water was set on a stirrer. Next, reagents (7.995 g/L of NaCl, 0.353 g/L of NaHCO.sub.3, 0.224 g/L of KCl, 0.174 g/L of K.sub.2HPO.sub.4, 0.305 g/L of MgCl.sub.2.6H.sub.2O, 0.368 g/L of CaCl.sub.2.2H.sub.2O, 0.071 g/L of Na.sub.2SO.sub.4) were weighed, and each reagent was sequentially added to and dissolved in the distilled water in such a manner that the next one is added after the first-added one has been completely dissolved, thereby preparing a solution. The reagent adhering to the powder paper was dissolved in the solution by spraying distilled water thereonto. Next, 90 ml of distilled water was added to 10 ml of 35% hydrochloric acid to prepare a diluted hydrochloric acid, and this was added to the solution little by little until the solution became noncloudy. Next, the solution was transferred to a 2-liter beaker, 825 ml of distilled water was added thereto, and stirred with a hot stirrer. Next, a pH meter was prepared, and diluted hydrochloric acid was gradually added through a dropper and dissolved to make the solution have a pH 2. Subsequently, 6.057 (g/L) of trishydroxymethylaminomethane (Tris-buffer) was dissolved in the solution to have a pH 8, and then, with heating with a hot stirrer, diluted hydrochloric acid was gradually added to finally give a solution having a pH or 7.25 at a liquid temperature 37° C. This solution was transferred to a plugged measuring cylinder, distilled water was added thereto to be 1 L and well shaken to mix the solution. The resultant solution was transferred to a plastic bottle, and then stored in a refrigerator for 1 day or more, thereby preparing the simulated body fluid for use in the experiment.

[0068] Regarding the theoretical value of the inorganic ion concentration of the simulated body fluid, Na.sup.+ is 142.0, K.sup.+ is 5.0, Mg.sup.2+ is 1.5, Ca.sup.2+ is 2.5, Cl.sup.− is 148.8, and HPO.sup.4− is 1.0 (the unit is all mM).

[0069] The spinning temperature was measured as follows: First, the massive glass sample was ground into a suitable size, and put into an alumina-made crucible in such a manner that air-bubbling thereinto could be minimized. Subsequently, the alumina crucible was heated so that the sample therein could be in a molten state, and the glass viscosity at different temperatures was determined according to a platinum ball pulling method. Subsequently, a viscosity curve was drawn from the resultant plural measured values, and according to an interpolation method, a temperature to give 10.sup.1.0 dPa.Math.s was calculated.

[0070] The liquidus temperature was measured as follows: First, the massive glass sample was ground to have a size falling within a range of 300 to 500 μm, and in that state, this was filled in a fireproof container to be in a state having a suitable bulk density. Subsequently, this fireproof container was put in an indirect-heating temperature-gradient furnace, statically left therein, and heated in air for 16 hours. Subsequently, the specimen was taken out along with the fireproof container from the temperature-gradient furnace, and cooled down to room temperature. Subsequently, the glass sample was observed with an optical microscope and checked for the crystal deposition part therein, and from the temperature distribution information inside the temperature-gradient furnace, the crystal deposition temperature (liquidus temperature) was specified. According to the method, the liquidus temperature was specified.

[0071] The average fiber diameter was measured as follows: First, using a scanning electron microscope (HITACHI s-3400N Type II), a secondary electron image or a reflected electron image of glass fibers was taken. Using the length measuring function of the scanning electron microscope, the diameter of 50 glass fibers was measured, and the measured values were averaged to give an average value to be the average fiber diameter.