Preparation, degradation, and calcification of biodegradable polyurethane foams for bone graft substitutes
Preparation, degradation, and calcification of biodegradable polyurethane foams for bone graft substitutes
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DOI：
10.1002/jbm.a.10148
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发表时间：
2003-12-01
影响因子：
4.9
通讯作者：
Gogolewski, S
中科院分区：
文献类型：
--
作者：
Gorna, K;Gogolewski, S
自体松质骨移植用于修复颌面部骨骼中关键尺寸的节段性长骨缺损和缺损。骨移植物的获取是创伤性的，导致供体部位的发病率，并且经常导致并发症。因此，需要新的生物功能性骨移植替代物，其代替自体骨移植物，可用于促进临界尺寸缺损中的骨再生。多孔可生物降解弹性聚氨酯支架与患者自身的骨髓结合可能是这样的骨替代品。弹性骨替代物防止骨和刚性骨之间的界面处的剪切力，陶瓷骨替代并与天然骨末端建立紧密接触，从而促进成骨细胞的增殖和骨再生。以生物相容性良好的聚氨酯为原料，合成了亲水性可控的三维交联可生物降解聚氨酯骨支架（泡沫）。支架具有70：30、50：50和30：70的亲水性与疏水性含量比。所用的反应物是二异氰酸酯、聚环氧乙烷二醇（M-W = 600）（亲水性组分）和聚（ε-己内酯）二醇（M-W = 2000），基于胺的多元醇（M-W = 515）或蔗糖基多元醇（男-女= 445）（疏水性组分），水作为扩链剂和发泡剂，以及辛酸亚锡，二月桂酸二丁基锡，乙酰丙酮铁，和草酸锌作为催化剂。柠檬酸用作钙络合剂，碳酸钙、甘油磷酸钙盐和羟基磷灰石用作无机填料，卵磷脂或维生素D溶液用作表面活性剂。支架具有开孔结构，其孔的大小和几何形状取决于材料的化学成分。支架的压缩强度在4-340 kPa范围内，压缩模量在9-1960 kPa范围内，其值随着聚己内酯含量的增加而增加。在两种材料中，具有相同量的聚己内酯的压缩强度和模量较高的一个含有无机填料。该支架吸收水分并在体外进行可控降解。随着聚合物链中聚环氧乙烷链段含量的增加和材料中钙络合部分的存在，吸收水的量和对降解的敏感性增加。所有聚氨酯支架诱导磷酸钙晶体的沉积，其结构和钙：磷原子比取决于聚氨酯的化学组成，并且从1.52-2.0变化。(C)2003 Wiley Periodicals，Inc.
Autogenous cancellous bone graft is used to heal critical-size segmental long bone defects and defects in the maxillofacial skeleton. Harvesting of bone graft is traumatic, causes morbidity of the donor site, and often results in complications. Thus, there is a need for new biologically functional bone graft substitutes that, instead of autogenous bone graft, could be used to facilitate bone regeneration in critical-size defects. Porous biodegradable elastomeric polyurethane scaffolds combined with the patient's own bone marrow could potentially be such bone substitutes. The elastomeric bone substitute prevents shear forces at the interface between bone and rigid, e.g., ceramic bone substitutes and establishes an intimate contact with the native bone ends, thus facilitating the proliferation of osteogenic cells and bone regeneration. Crosslinked 3D biodegradable polyurethane scaffolds (foams) with controlled hydrophilicity for bone graft substitutes were synthesized from biocompatible reactants. The scaffolds had hydrophilic-to-hydrophobic content ratios of 70:30, 50:50, and 30:70. The reactants used were hexamethylene diisocyanate, poly(ethylene oxide) diol (M-W = 600) (hydrophilic component), and poly(epsilon-caprolactone) diol (M-W = 2000), amine-based polyol (M-W = 515) or sucrose-based polyol (M-W = 445) (hydrophobic component), water as the chain extender and foaming agent, and stannous octoate, dibutyltin dilaurate, ferric acetylacetonate, and zinc octoate as catalysts. Citric acid was used as a calcium complexing agent, calcium carbonate, glycerol phosphate calcium salt, and hydroxyapatite were used as inorganic fillers, and lecithin or solutions of vitamin D, were used as surfactants. The scaffolds had an open-pore structure with pores whose size and geometry depended on the material's chemical composition. The compressive strengths of the scaffolds were in the range of 4-340 kPa and the compressive moduli in the range of 9-1960 kPa, the values of which increased with increasing content of polycaprolactone. Of the two materials with the same amount of polycaprolactone the compressive strengths and moduli were higher for the one containing inorganic fillers. The scaffolds absorbed water and underwent controlled degradation in vitro. The amount of absorbed water and susceptibility to degradation increased with the increasing content of the polyethylene oxide segment in the polymer chain and the presence in the material of calcium complexing moiety. All polyurethane scaffolds induced the deposition of calcium phosphate crystals, the structure and calcium:phosphorus atomic ratio of which depended on the chemical composition of the polyurethane and varied from 1.52-2.0. (C) 2003 Wiley Periodicals, Inc.