Heparin modification of a biomimetic bone matrix for controlled release of VEGF
Heparin modification of a biomimetic bone matrix for controlled release of VEGF
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DOI：
10.1002/jbm.a.35020
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发表时间：
2014-10-01
影响因子：
4.9
通讯作者：
Gelinsky, Michael
中科院分区：
文献类型：
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作者：
Knaack, Sven;Lode, Anja;Gelinsky, Michael
使用组织工程构建体进行骨再生需要有效刺激这种构建体内血管化的策略，这对于其供应和与宿主组织的整合至关重要。在这项工作中，用肝素修饰胶原/羟基磷灰石纳米复合材料的多孔支架，以生成能够以受控方式释放血管生成因子的仿生骨基质。肝素要么在材料合成过程中（原位）被整合，要么在支架制造后（后）被添加到支架中。两种方法均可使肝素稳定地掺入矿化胶原基质中。对加载到支架上的血管内皮生长因子（VEGF- a(165)）的结合和释放的研究表明，两种肝素修饰方法都增强了血管内皮生长因子的结合能力，并能持续且几乎恒定地递送血管内皮生长因子。通过改变肝素掺入量和修饰方法可以控制其释放速度。虽然与对照VEGF相比，未经修饰的支架在7天后释放的VEGF的生物活性有所降低，但在原位修饰支架释放后，其生物活性保持不变，甚至在原位修饰支架释放后，其生物活性有所增强。综上所述，肝素修饰的矿化胶原支架具有良好的生长因子结合和释放特性，可能有利于刺激血管形成。(C) 2013 Wiley期刊公司
Bone regeneration using tissue engineered constructs requires strategies to effectively stimulate vascularization within such a construct that is crucial for its supply and integration with the host tissue. In this work, porous scaffolds of a collagen/hydroxyapatite nanocomposite were modified with heparin to generate biomimetic bone matrices which are able to release angiogenic factors in a controlled manner. Heparin was either integrated during material synthesis (in situ) or added to the scaffolds after their fabrication (post). Both approaches resulted in stable incorporation of heparin into the matrix of mineralized collagen. Investigations of binding and release of the vascular endothelial growth factor (VEGF-A(165)) loaded onto the scaffolds revealed an enhanced binding capacity as well as a sustained and nearly constant delivery of VEGF as result of both heparin modification methods. The release rate could be controlled by varying the quantity of incorporated heparin and the modification method. Although the biological activity of VEGF released after 7 days from the unmodified scaffolds was reduced in comparison to control VEGF, it was maintained after release from post or even enhanced after release from in situ modified scaffolds. In conclusion, the heparin-modified scaffolds of mineralized collagen exhibited favorable growth factor binding and release properties and may be beneficial to stimulate vascularization. (C) 2013 Wiley Periodicals, Inc.