Laboratory for Radiopharmacy, Gent University, Ghent, Belgium.
J Mater Sci Mater Med. 2012 Aug;23(8):1961-9. doi: 10.1007/s10856-012-4668-5. Epub 2012 May 9.
This study covers the quantification of the covalent attachment of gelatin type B (GelB) and the subsequent adsorption of Fibronectin (Fn) on poly-ε-caprolactone (PCL) surfaces, functionalised with 2-aminoethyl methacrylate (AEMA) by means of post-plasma UV-irradiation grafting. As typical surface characterisation tools do not allow quantification of deposited amounts of GelB or Fn, radiolabeled analogues were used for direct measurement of the amount of immobilized material. Bolton-Hunter GelB (BHG) and Fn were radioiodinated with (131)I and (125)I respectively and S-Hynic GelB (SHG) was labeled with (99m)Tc. Immobilisation of (131)I-BHG or (99m)Tc-SHG on both PCL and PCL-AEMA scaffolds was performed in analogy with earlier work. SPECT images on scaffolds coated with (99m)Tc-SHG conjugates were acquired on a U-SPECT II camera. There was a clear difference in the amount of deposited (131)I-BHG between blanco and AEMA-grafted PCL on 2D samples. No significant differences in immobilization behaviour were observed between (99m)Tc-SHG and (131)I-BHG. Subsequent immobilisation of Fn was successful and depended on the amounts of deposited GelB. SPECT imaging on cylindrical 3D scaffolds confirmed these findings and showed that the amount of immobilized (99m)Tc-SHG was depth dependant. The architecture of the scaffolds strongly influences the distribution of GelB within these structures. Furthermore, there is a clear difference in the homogeneity of the protein coating when different GelB immobilization protocols were applied. This study shows that radiolabeled compounds are a rapid and accurate tool in the quantitative and qualitative evaluation of the biofunctionalisation of AEMA grafted PCL scaffolds.
本研究涵盖了通过后等离子体 UV 辐照接枝，在 2-氨基乙基甲基丙烯酸酯（AEMA）功能化的聚己内酯（PCL）表面定量测定明胶 B 型（GelB）的共价结合，以及随后的纤连蛋白（Fn）吸附。由于典型的表面特性分析工具无法定量测定 GelB 或 Fn 的沉积量，因此使用放射性标记的类似物进行了固定化材料的直接测量。 Bolton-Hunter GelB（BHG）和 Fn 分别用（131）I 和（125）I 放射性碘标记，S-Hynic GelB（SHG）用（99m）Tc 标记。（131）I-BHG 或（99m）Tc-SHG 在 PCL 和 PCL-AEMA 支架上的固定化是按照早期的工作进行的。用（99m）Tc-SHG 缀合物涂覆的支架上进行 SPECT 图像采集，使用 U-SPECT II 相机。在 2D 样本中，空白和 AEMA 接枝 PCL 之间沉积的（131）I-BHG 量有明显差异。（99m）Tc-SHG 和（131）I-BHG 的固定化行为没有显著差异。随后成功固定化了 Fn，并且取决于沉积的 GelB 量。在圆柱形 3D 支架上的 SPECT 成像证实了这些发现，并表明固定化的（99m）Tc-SHG 量取决于深度。支架的结构强烈影响 GelB 在这些结构中的分布。此外，当应用不同的 GelB 固定化方案时，蛋白质涂层的均匀性有明显差异。本研究表明，放射性标记化合物是定量和定性评估 AEMA 接枝 PCL 支架生物功能化的快速准确工具。
