Wu Meiling, Sapin-Minet Anne, Stefan Loïc, Perrin Julien, Raeth-Fries Isabelle, Gaucher Caroline
Université de Lorraine, CITHEFOR, F-54000 Nancy, France.
Université de Lorraine, CNRS, LCPM, F-54000 Nancy, France.
Int J Pharm. 2025 Feb 10;670:125126. doi: 10.1016/j.ijpharm.2024.125126. Epub 2024 Dec 22.
As the main protein forming the vascular extracellular matrix, collagen has a weak antigenicity, making it an attractive candidate for coatings of vascular grafts. In order to bring antithrombotic properties to collagen for obtaining suitable blood compatibility of surfaces and further bioactive molecule carrying capacity, heparinization appears as a method of choice. Thus, in this article, pH-driven self-assembly was used to form collagen-based hydrogels with physical incorporation of heparins, especially low molecular weight heparin or unfractionated heparin at 1 IU/mL and 6 IU/mL. These heparinized hydrogels were evaluated for their physicochemical properties including gelation kinetic, spreading, viscoelasticity, microstructure and heparin quantification, and their biocompatibility such as cytocompatibility and their capacity to release bioactive heparins with antithrombotic properties. The loading capacity of collagen-based hydrogels was higher for unfractionated heparin (60 to 80 %) than for low molecular weight heparin (20 %). Interestingly, the highest concentration (6 IU/mL) of heparin used to form collagen-based hydrogels resulted in the formation of a softer hydrogel owning a better spreadability compared to 1 IU/mL and non heparinized collagen-based hydrogel. The 3D structure observation showed a layered formation with visible pores or spaces between the layers in all types of collagen-based hydrogels. These layers are interconnected by fibrous structures, suggesting a networked architecture. Moreover, the amount of heparin released from collagen-based hydrogel prepared with 6 IU /mL was higher than from those heparinized with 1 IU/mL attested by a delay in blood coagulation (activated partial thromboplastin time and thrombin time) and the abolishment of thrombin generation. Those hydrogels were also biocompatible, with low albumin adsorption and no impact on cell viability. Finally, heparin is retained in these hydrogels for at least seven days after cell seeding, providing the possibility of long-term antithrombotic properties. Thus, we succeeded in develop/obtain coatings with antithrombogenic properties, biocompatible and able to retain heparins at least seven days, making them good candidates with a great potential for the development and application of efficient blood-contacting materials.
作为构成血管细胞外基质的主要蛋白质，胶原蛋白具有较弱的抗原性，这使其成为血管移植物涂层的理想候选材料。为了赋予胶原蛋白抗血栓特性，以实现表面合适的血液相容性以及进一步的生物活性分子承载能力，肝素化成为一种首选方法。因此，在本文中，采用pH驱动的自组装方法来形成基于胶原蛋白的水凝胶，并通过物理方式掺入肝素，特别是1 IU/mL和6 IU/mL的低分子量肝素或未分级肝素。对这些肝素化水凝胶的物理化学性质进行了评估，包括凝胶化动力学、铺展性、粘弹性、微观结构和肝素定量，以及它们的生物相容性，如细胞相容性及其释放具有抗血栓特性的生物活性肝素的能力。基于胶原蛋白的水凝胶对未分级肝素的负载能力（60%至80%）高于低分子量肝素（20%）。有趣的是，与1 IU/mL和未肝素化的基于胶原蛋白的水凝胶相比，用于形成基于胶原蛋白的水凝胶的肝素最高浓度（6 IU/mL）导致形成了一种更柔软、铺展性更好的水凝胶。三维结构观察显示，在所有类型的基于胶原蛋白的水凝胶中均形成了分层结构，层间有可见的孔隙或空间。这些层通过纤维结构相互连接，表明形成了网络状结构。此外，通过凝血延迟（活化部分凝血活酶时间和凝血酶时间）以及凝血酶生成的消除证明，用6 IU/mL制备的基于胶原蛋白的水凝胶释放的肝素量高于用1 IU/mL肝素化的水凝胶。这些水凝胶也具有生物相容性，白蛋白吸附量低且对细胞活力无影响。最后，细胞接种后，肝素在这些水凝胶中至少保留七天，提供了长期抗血栓特性的可能性。因此，我们成功开发/获得了具有抗血栓形成特性、生物相容性且能够将肝素保留至少七天的涂层，使其成为高效血液接触材料开发和应用的极具潜力的良好候选材料。
