초록 ▼

The present invention relates to a nano-calcium phosphates/collagen composite that mimics the natural bone, both in composition and microstructure, as well as porous bone substitute and tissue engineering scaffolds made by a complex of said composite and poly(lactic acid)(PLA) or poly(lactic acid-co

The present invention relates to a nano-calcium phosphates/collagen composite that mimics the natural bone, both in composition and microstructure, as well as porous bone substitute and tissue engineering scaffolds made by a complex of said composite and poly(lactic acid)(PLA) or poly(lactic acid-co-glycolic acid)(PLGA). The invention also relates to the use of said scaffold in treating bone defect and bone fracture.

대표청구항 ▼

1. A nano-calcium phosphate/collagen composite, comprising collagen molecules and nano-calcium phosphate, wherein said composite comprises agglomerated particles having a diameter of 5-50 microns, wherein the agglomerated particles comprise a multiple laminar structure having periodically repeated u

1. A nano-calcium phosphate/collagen composite, comprising collagen molecules and nano-calcium phosphate, wherein said composite comprises agglomerated particles having a diameter of 5-50 microns, wherein the agglomerated particles comprise a multiple laminar structure having periodically repeated units, each periodically repeated unit having a thickness of 10-15 nm and consisting of a layer of calcium phosphates and a layer of collagen.2. The nano-calcium phosphates/collagen composite of claim 1, wherein the collagen is type I collagen.3. The nano-calcium phosphates/collagen composite of claim 1, wherein the weight ratio of nano-calcium phosphates to collagen molecules is between about 2.2 to about 2.8.4. A process for preparing the composite of claim 1, comprising the following steps:(a) dissolving collagen gel in acetic acid, then adding aqueous solutions of sodium phosphate and calcium chloride, wherein the weight ratio of Ca:P is between 1:1 to 1.67:1; (b) adding in drops sodium hydroxide solution until the calcium phosphates start to co-precipitate with collagen; (c) maintaining the solution of step (b) at a neutral pH and incubating the solution at 30° C. for 1?5 days; and (d) harvesting the composite by centrifugation, freeze-drying and grinding into fine powder. 5. A porous scaffold for use as a bone substitute or in tissue engineering, comprising a complex of the composite of claim 1 and poly(lactic acid) or poly(lactic acid-co-glycolic acid), wherein the weight ratio of said composite and poly(lactic acid) or poly(lactic acid-co-glycolic acid) is between about 3:7 to about 1:1, the porosity is about 70% or more and the pore size is about 100-500 microns.6. The scaffold of claim 5, further comprising noncollagenous bone matrix proteins selected from the group consisting of bone morphogenetic protein, bone growth factors and glycoproteins that can promote cell attachment and spreading.7. A process for preparing a porous scaffold for use as a bone substitute or in tissue engineering, comprising the following steps:(a) dissolving poly(lactic acid) or poly(lactic acid-co-glycolic acid) in dioxane to a final concentration of about 2.5-15%(w/v), then stirring the solution gently for about 4 to 6 hours; (b) adding the nano-calcium phosphate/collagen composite powder of claim 1 with a ratio of composite: poly(lactic acid) or poly(lactic acid-co-glycolic acid) of about 3:7 to 1:1; (c) ultrasonicating the solution of step (b), then pouring the solution into a mold and freezing at a temperature between 0 to ?20° C. overnight; and (d) transferring the frozen molded solution into a freeze drying machine to remove dioxane to obtain said scaffold. 8. A porous scaffold obtained by the process of claim 7.9. A method of treating bone defect or bone fracture, said method comprising administering to said bone defect or bone fracture an effective amount of a scaffold according to claim 5, 6 or 8.10. A method of culturing osteocytes, said method comprising providing an effective amount of a scaffold according to claim 5, 6 or 8 for culturing osteocytes.