PDF(Pubmed)
Abstract：
Fabrication of porous tissue-engineering scaffolds from bioactive glasses (BAG) is complicated by the tendency of BAG compositions to crystallize in thermal treatments during scaffold manufacture. Here, experimental biocompatible glass S59 (SiO2 59.7 wt%, Na2O 25.5 wt%, CaO 11.0 wt%, P2O5 2.5 wt%, B2O3 1.3 wt%), known to be resistant to crystallization, was used in sintering of glass granules (300-500 µm) into porous scaffolds. The dissolution behavior of the scaffolds was then studied in vivo in rabbit femurs and under continuous flow conditions in vitro (14 days in vitro/56 days in vivo). The scaffolds were osteoconductive in vivo, as bone could grow into the scaffold structure. Still, the scaffolds could not induce sufficiently rapid bone ingrowth to replace the strength lost due to dissolution. The scaffolds lost their structure and strength as the scaffold necks dissolved. In vitro, S59 dissolved congruently throughout the 14-day experiments, resulting in only a slight reaction layer formation. Manufacturing BAG scaffolds from S59 that retain their amorphous structure was thus possible. The relatively rapid and stable dissolution of the scaffold implies that the glass S59 may have the potential to be used in composite implants providing initial strength and stable, predictable release of ions over longer exposure times.
摘要：
由生物活性玻璃(BAG)制造多孔组织工程支架由于BAG组合物在支架制造期间的热处理中结晶的倾向而变得复杂。这里,实验生物相容性玻璃S59(SiO259.7wt%，Na2O25.5wt%,CaO11.0wt%,P2O52.5wt%,B2O31.3wt%)，已知抗结晶，用于将玻璃颗粒（300-500µm）烧结成多孔支架。然后在兔股骨中和在体外连续流动条件下(体外14天/体内56天)研究支架的溶解行为。支架在体内具有骨传导性，骨可以长入支架结构。尽管如此，支架不能诱导足够快速的骨向内生长以代替由于溶解而损失的强度。当支架颈部溶解时,支架失去其结构和强度。体外，S59在整个14天的实验中一致溶解，仅导致轻微的反应层形成。因此,制造保留其无定形结构的来自S59的BAG支架是可能的。支架的相对快速和稳定的溶解意味着玻璃S59可能具有用于提供初始强度和稳定的复合植入物的潜力。在更长的暴露时间内可预测的离子释放。
