Functionalization with a VEGFR2‐binding antibody fragment leads to enhanced endothelialization of a cardiovascular stent in vitro and in vivo

Abstract

Rapid endothelialization of cardiovascular stents is critical to prevent major clinical complications such as restenosis. Reconstruction of the native endothelium on the stent surface can be achieved by the capture of endothelial progenitor cells (EPCs) or neighboring endothelial cells (ECs) in vivo. In this study, stainless steel cardiovascular stents were functionalized with recombinant scFv antibody fragments specific for vascular endothelial growth factor receptor‐2 (VEGFR2) that is expressed on EPCs and ECs. Anti‐VEGFR2 scFvs were expressed in glycosylated form in Escherichia coli and covalently attached to amine‐functionalized, titania‐coated steel disks and stents. ScFv‐coated surfaces exhibited no detectable cytotoxicity to human ECs or erythrocytes in vitro and bound 15 times more VEGFR2‐positive human umbilical vein ECs than controls after as little as 3 min. Porcine coronary arteries were successfully stented with scFv‐coated stents with no adverse clinical events after 30 days. Endovascular imaging and histology revealed coverage of the anti‐VEGFR2 scFv‐coated stent with a cell layer after 5 days and the presence of a neointima layer with a minimum thickness of 80 μm after 30 days. Biofunctionalization of cardiovascular stents with endothelial cell‐capturing antibody fragments in this manner offers promise in accelerating stent endothelialization in vivo. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:213–224, 2020.

Designing Cardiovascular Implants Taking in View the Endothelial Basement Membrane

“…The most frequently studied antibodies are directed against specific markers of EPC (e.g., CD34 and CD133) and fully differentiated EC (e.g., CD31 and VEGFR2). For example, coating of stents with VEGFR2 antibody fragments enhanced endothelialization in vitro and in vivo, as shown by increased EC adhesion and the formation of an endothelial monolayer (neointima) after 30 days in porcine coronary arteries [ 87 ]. Moreover, surface coating of ePTFE with ECM and monoclonal anti-CD34 antibodies significantly increased EC adhesion and decreased platelet attachment [ 88 ].…”

Recent advance in treatment of atherosclerosis: Key targets and plaque-positioned delivery strategies

“… 325 – 327 Fixation of antibody can work as another potent candidate, as antibody fragments scFv, single chain fragment variable binding to VEGFR2 mediating VEGFR2-positive ECs to adhere and reproduce on the stent surface. 328 Meanwhile, burgeoning gene therapies also serve as the encouragement of migratory and proliferative effects of vascular endothelial cells, such as ZNF580 gene, 310 DNA encoding for human VEGF 329 and CD39-encoding mRNA. 330 …”

“…Park et al 344 unwrapped that stents integrating anti-CD146 antibody could capture more late-EPCs as well as mesenchymal stem cells (MSCs) in vitro. More biomarkers of EPCs have emerged in this research field, touching upon CD34, 345 CD133, 346 vascular endothelial-cadherin (VE-cadherin), 347 CD146, 344 endoglin, 348 vascular endothelial growth factor type 2 receptor (VEGFR2), 328 CD144, and CD309. 349 Fixation of antibody for bounding these biomarkers onto materials could potently attract these cells to pathological sites.…”

“…Antibody fragments scFv, single chain fragment variable binding to VEGFR2 can be utilized to guide attachment and multiplying of VEGFR2-positive cells covering circulating ECs and EPCs. 328 What’s more, specific peptide ligands also have been defined, involving integrin-combined peptide ligand, such as αvβ3-integrin-binding peptide cyclic Arg-Gly-Asp peptide 350 and LXW7 (an octamer disulfide cyclic peptide (cGRGDdvc)). 351 In the example, LXW7 potently and specifically immobilized to αvβ3-integrin of EPC/EC, but presented weaker binding to platelets and no binding to THP-1 monocytes.…”

Potential strategies to prevent encrustations on urinary stents and catheters – thinking outside the box: a European network of multidisciplinary research to improve urinary stents (ENIUS) initiative

“…Antibodies on the stent surface target receptors on cells responsible for these processes effectively enhancing vascularization and preventing intimal hyperplasia and thrombosis [10][11][12][13][14]. In addition, the same stents can be designed as drug-eluting [12].…”