Substrate-enzyme affinity-based surface modification strategy for endothelial cell-specific binding under shear stress

Article type: Research Article

Authors: Lee, Seahyoung^{a; 1; *} | Ganesan, Ramakrishnan^{a; 2} | Krüger-Genge, Anne^{a; 3} | Kratz, Karl^a | Franke, Ralf-Peter^b | Lendlein, Andreas^{a; c} | Jung, Friedrich^{a; *}

Affiliations: [a] Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Teltow, Germany | [b] Central Institute for Biomedical Engineering, University of Ulm, Ulm, Germany | [c] Institute of Chemistry, University of Potsdam, Potsdam, Germany

Correspondence: [*] Corresponding authors: Seahyoung Lee, Tel.: +49 3328 352 269; Fax: +49 3328 352 452; E-mail: [email protected] and Friedrich Jung, Tel.: +82 32 290 2775; Fax: +82 32 290 2774; E-mail: [email protected].

Note: [1] Current address: Institute for Bio-Medical Convergence, College of Medicine, Catholic Kwandong University, Gangneung, Gangwon-do 210-701, Republic of Korea.

Note: [2] Current address: Birla Institute of Technology and Science, Department of Chemistry, Jawahar Nagar, Shameerpet Mandal, Hyderabad. 500078 India.

Note: [3] Current address: Department of Anaesthesia, Pain Management and Perioperative Medicine, Faculty of Medicine, Dalhousie University, Halifax, Canada.

Abstract: Establishing an endothelial cell (EC) monolayer on top of the blood contacting surface of grafts is considered to be a promising approach for creating a hemocompatible surface. Here we utilized the high affinity interactions between the EC plasma membrane expressed enzyme called endothelin converting enzyme-1 (ECE-1) and its corresponding substrate big Endothelin-1 (bigET-1) to engineer an EC-specific binding surface. Since enzymatic cleavage of substrates require physical interaction between the enzyme and its corresponding substrate, it was hypothesized that a surface with chemically immobilized synthetic bigET-1 will preferentially attract ECs over other types of cells found in vascular system such as vascular smooth muscle cells (VSMCs). First, the expression of ECE-1 was significantly higher in ECs, and ECs processed synthetic bigET-1 to produce ET-1 in a cell number-dependent manner. Such interaction between ECs and synthetic bigET-1 was also detectible in blood. Next, vinyl-terminated self-assembled monolayers (SAMs) were established, oxidized and activated on a glass substrate as a model to immobilize synthetic bigET-1 via amide bonds. The ECs cultured on the synthetic bigET-1-immobilized surface processed larger amount of synthetic bigET-1 to produce ET-1 compared to VSMCs (102.9±5.13 vs. 9.75±0.74 pg/ml). The number of ECs bound to the synthetic bigET-1-immobilized surface during 1 h of shearing (5dyne/cm2) was approximately 3-fold higher than that of VSMCs (46.25±12.61 vs. 15.25±3.69 cells/100×HPF). EC-specific binding of synthetic bigET-1-immobilized surface over a surface modified with collagen, a common substance for cell adhesion, was also observed. The present study demonstrated that using the substrate-enzyme affinity (SEA) of cell type-specific enzyme and its corresponding substrate can be an effective method to engineer a surface preferentially binds specific type of cells. This novel strategy might open a new route toward rapid endothelialization under dynamic conditions supporting the long-term patency of cardiovascular implants.

Keywords: Endothelin converting enzyme-1, big endothelin-1, endothelialization, shear resistance

DOI: 10.3233/CH-190736

Journal: Clinical Hemorheology and Microcirculation, vol. 75, no. 1, pp. 85-98, 2020