Abstract：
The structure and handling properties of a P407 hydrogel-based bone substitute material (BSM) might be affected by different poloxamer P407 and silicon dioxide (SiO2) concentrations. The study aimed to compare the mechanical properties and biological parameters (bone remodeling, BSM degradation) of a hydroxyapatite: silica (HA)-based BSM with various P407 hydrogels in vitro and in an in vivo rat model. Rheological analyses for mechanical properties were performed on one BSM with an SiO2-enriched hydrogel (SPH25) as well on two BSMs with unaltered hydrogels in different gel concentrations (PH25 and PH30). Furthermore, the solubility of all BSMs were tested. In addition, 30 male Wistar rats underwent surgical creation of a well-defined bone defect in the tibia. Defects were filled randomly with PH30 (n = 15) or SPH25 (n = 15). Animals were sacrificed after 12 (n = 5 each), 21 (n = 5 each), and 63 days (n = 5 each). Histological evaluation and histomorphometrical quantification of new bone formation (NB;%), residual BSM (rBSM;%), and soft tissue (ST;%) was conducted. Rheological tests showed an increased viscosity and lower solubility of SPH when compared with the other hydrogels. Histomorphometric analyses in cancellous bone showed a decrease of ST in PH30 (p = .003) and an increase of NB (PH30: p = .001; SPH: p = .014) over time. A comparison of both BSMs revealed no significant differences. The addition of SiO2 to a P407 hydrogel-based hydroxyapatite BSM improves its mechanical stability (viscosity, solubility) while showing similar in vivo healing properties compared to PH30. Additionally, the SiO2-enrichment allows a reduction of poloxamer ratio in the hydrogel without impairing the material properties.
摘要：
P407基于水凝胶的骨替代材料（BSM）的结构和处理性能可能会受到不同的泊洛沙姆P407和二氧化硅（SiO2）浓度的影响。该研究旨在比较力学性能和生物学参数(骨重建，BSM降解）在体外和体内大鼠模型中使用各种P407水凝胶的基于羟基磷灰石：二氧化硅（HA）的BSM。对具有SiO2富集的水凝胶（SPH25）的一个BSM以及具有不同凝胶浓度（PH25和PH30）的未改变的水凝胶的两个BSM进行了机械性能的流变分析。此外，测试了所有BSM的溶解度。此外,30只雄性Wistar大鼠接受了胫骨中明确定义的骨缺损的手术创建。用PH30(n=15)或SPH25(n=15)随机填充缺陷。12后处死动物（每个n=5），21（每个n=5），和63天（n=5）。新骨形成的组织学评估和组织形态计量学定量（NB;％），残余BSM(rBSM;%),和软组织（ST;%）进行。流变试验表明,与其它水凝胶相比,SPH的粘度增加,溶解度降低。松质骨的组织形态计量学分析显示，随着时间的推移，PH30中的ST降低（p=.003），NB增加（PH30：p=.001；SPH：p=.014）。两个BSM的比较显示没有显着差异。向P407水凝胶基羟基磷灰石BSM中添加SiO2可改善其机械稳定性（粘度，溶解度），同时显示与PH30相似的体内愈合特性。此外,SiO2富集允许在水凝胶中降低泊洛沙姆比率而不损害材料性质。
