Multiphasic Calcium Sulfate Bone Repair Material

描述（由申请人提供）：该项目评估了一种由硫酸钙 (CS) 颗粒组成的新型多相复合骨修复材料的可行性，该材料通过涂覆在 CS 基质上或内部的可吸收聚合物来防止快速降解。骨缺损的修复通常需要使用永久性或可吸收的生物材料。这些材料可包括自体或同种异体骨移植物、一系列异体（磷酸钙材料、生物玻璃、硫酸钙材料）材料以及这些材料的复合组合。硫酸钙（CS）是一种可完全降解的骨缺损修复材料。它是目前使用的最古老、最安全的生物材料之一。最近的研究表明，它具有生物相容性、完全可降解、骨传导性、不会引起炎症并且引起的异物反应极小。它可以与其他骨移植材料如自体移植物、磷酸钙、生物玻璃和同种异体移植物结合使用。它具有很强的止血活性，并作为屏障材料防止缺损区域的软组织向内生长。它刺激微血管的生长，因此具有血管生成作用。它在溶解时会导致磷酸钙沉积物沉淀。这些沉淀物刺激并指导新骨的形成。使用 CS 的从业者的主要担忧和抱怨是它（溶解）太快，并且在某些应用中超过了新骨的形成。聚左旋乳酸 (PLLA) 是另一种用于许多生物医学设备的生物材料，具有出色的安全记录。它具有生物相容性和可生物降解性。我们之前的研究表明，硫酸钙和 PLLA 的复合材料在模拟体液中的溶解速度比纯 CS 慢得多。当这种复合材料降解时，会形成磷酸钙沉淀（这会刺激体内骨骼的形成）。根据 CS:PLLA 的比例，可以控制复合材料的降解速率。这里描述的产品代表一种水泥，可以配制为以受控速率溶解，可以与特定手术应用的骨修复相匹配。这种复合材料将克服硫酸钙快速溶解的缺点，但仍保留其用于骨移植的所有独特性能。填充拔牙位点、增强上颌骨和下颌骨以接受牙种植体并加速牙种植体的骨整合的新材料有现成的市场。

DESCRIPTION (provided by applicant): This project evaluates the feasibility of a new multiphasic, composite bone repair material composed of calcium sulfate (CS) particulate, protected from rapid degradation by an absorbable polymer either coated on, or within, a CS matrix. Repair of bone defects often requires the use of permanent or resorbable biomaterials. These materials can comprise autogenous or allogeneic bone graft, a range of alloplastic (calcium phosphate materials, bioglass, calcium sulfate materials) materials and composite combinations of these materials. Calcium sulfate (CS) is a fully degradable material for repair of bone defects. It is one of the oldest and safest biomaterials in current use. Recent research has shown that it is biocompatible, completely degradable, osteoconductive, does not cause inflammation and evokes minimal foreign body response. It can be used in combination with other bone graft materials such as autograft, calcium phosphate, bioglass and allografts. It has strong hemostatic activity and it prevents the ingrowth of soft tissue in the defect area acting as a barrier material. It stimulates the growth of micro blood vessels and hence is angiogenic. It causes precipitation of calcium phosphate deposits as it undergoes dissolution. These precipitates stimulate and direct the formation of new bone. The principal concern and complaint by practitioners using CS is that it (dissolves) too rapidly and outpaces the formation of new bone in some applications. Poly (L Lactic acid), (PLLA) is another biomaterial used in many biomedical devices with an excellent safety record. It is biocompatible and biodegradable. Our previous studies have shown that a composite of calcium sulfate and PLLA undergoes much slower dissolution in simulated body fluid than pure CS. Calcium phosphate precipitate formed as this composite degraded (which would stimulate the formation of bone in vivo). Depending upon the ratio of CS:PLLA, the degradation rate of the composite can be controlled. The product described here represents a cement that can be formulated to dissolve at controlled rates that can be matched with bone repair for a specific surgical application. This composite would overcome the disadvantage of fast dissolution of calcium sulfate, but would still retain all of its unique properties for bone grafting. There is a ready market for a new material to fill extraction sites, enhance maxilla and mandibular bone to accept dental implants, and to speed up the osseointegration of dental implants.