Click Conjugation of Endothelial Cells to Hollow Fiber Membranes of Artificial Lungs for Improving Hemocompatibility

Background: Extracorporeal membrane oxygenation (ECMO) is performed in patients with severe lung failure to oxygenate blood and remove carbon dioxide. This is achieved by continuously circulating the patient’s blood through a gas-permeable membrane oxygenator composed of bundles of microporous hollow fiber membranes (HFMs). However, oxygenators still possess insufficient hemocompatibility, which can cause complications, such as thrombosis. While various coatings for blood-contacting surfaces have been established, the endothelium remains the ideal surface for blood contact. In this study, a clickable coating was established on the surface of HFMs for the efficient binding of metabolically labeled endothelial cells (ECs), and the subsequent endothelialization was analyzed.

Methods: HFMs were functionalized with dibenzylcyclooctyne (DBCO) and ECs (HUVECs and hiPSC-ECs) were glycoengineered for covalent conjugation to DBCO by a copper-free click reaction. The cell binding and the formation of an endothelium were first analyzed using HUVECs. Later, the potential of autologous hiPSC-derived ECs was evaluated. Furthermore, analyses by dynamic incubation with human blood were performed according to ISO-10993–4 guidelines to evaluate the effect of surface modification and endothelialization on hemocompatibility.

Results: Metabolic glycoengineering resulted in highly efficient functionalization of HUVECs. Significantly improved endothelialization was detected on the HFM surfaces functionalized with DBCO compared with unmodified HFMs after 48 hours. The hemocompatibility analyses of HFMs showed that the endothelialization of HFMs significantly reduced the activation of blood coagulation and platelets. Furthermore, using hiPSC-ECs a confluent endothelium could be detected with viability levels comparable to HUVECs and expression of EC-specific markers.

Conclusion: In this study, a novel, cell-compatible method for the endothelialization of blood-contacting surfaces was established based on glycoengineering of ECs and copper-free click reaction. The incubation of DBCO-functionalized HFMs with azide-labeled HUVECs and hiPSC-ECs resulted in the generation of a functional EC monolayer. In particular, hiPSC-ECs demonstrate great potential for endothelialization as they offer the possibility for patient-specific treatment options.

Publication History

Article published online:
11 February 2025