Laboratory for Experimental Trauma Surgery, University of Giessen, Germany.
J Tissue Eng Regen Med. 2011 Jan;5(1):11-9. doi: 10.1002/term.283.
This work reports the effects of phosphoserine addition on the biodegradability of calcium phosphate cements. The characteristics of a phosphoserine-modified calcium phosphate cement without collagen in a large animal model are presented here for the first time. Critical size bone defects in the proximal tibia of 10 sheep were filled with the bone cement, and five sheep with empty defects were included as controls. The sheep were sacrificed after either 10 days or 12 weeks, and bones were processed for histological, histomorphometric and enzyme histochemical analyses as well as transmission electron microscopic examination. After 12 weeks, there was no significant reduction in either the implant or the bone defect cross-sectional area. Different amounts of fibrous tissue were observed around the implant and in the bone defect after 12 weeks. The direct bone-implant contact decreased after 12 weeks (p = 0.034). Although the implanted material properly filled the defect and promoted an initial activation of macrophages and osteoblasts, the resorption and simultaneous substitution did not reach expected levels during the experimental time course. Although other studies have shown that the addition of phosphoserine to calcium phosphate cements that have already been modified with collagen I resulted in an acceleration of cement resorption and bone regeneration, this study demonstrates that phosphoserine-modified calcium phosphate cements without collagen perform poorly in the treatment of bone defects. Efforts to use phosphoserine in the development of new composites should take into consideration the need to improve osteoconduction simultaneously via other means.
本研究报告了添加磷酸丝氨酸对磷酸钙骨水泥生物降解性的影响。本文首次报道了一种无胶原的磷酸丝氨酸改性磷酸钙骨水泥在大动物模型中的特性。在 10 只绵羊的胫骨近端临界尺寸骨缺损中填充了骨水泥，同时纳入 5 只存在空骨缺损的绵羊作为对照。在 10 天或 12 周后处死绵羊，对骨骼进行组织学、组织形态计量学和酶组织化学分析以及透射电镜检查。12 周后，植入物或骨缺损的横截面积均无明显减少。12 周后，在植入物周围和骨缺损中观察到不同量的纤维组织。12 周后，直接骨-植入物接触减少（p = 0.034）。尽管植入材料适当地填充了缺损，并促进了巨噬细胞和成骨细胞的初始激活，但在实验过程中，吸收和同时替代没有达到预期水平。尽管其他研究表明，向已经用 I 型胶原改性的磷酸钙骨水泥中添加磷酸丝氨酸可加速水泥的吸收和骨再生，但本研究表明，无胶原的磷酸丝氨酸改性磷酸钙骨水泥在治疗骨缺损方面效果不佳。在开发新型复合材料时使用磷酸丝氨酸，应考虑通过其他手段同时提高骨传导性。
