Attachment of endothelial colony-forming cells onto a surface bearing immobilized anti-CD34 antibodies: Specific CD34 binding versus nonspecific binding.
Anouck L. S. Burzava, M. Jasieniak, Michaelia P Cockshell, N. Voelcker, C. Bonder, H. J. Griesser, E. Moore
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引用次数: 0
Abstract
Cardiovascular disease is a leading cause of death worldwide; however, despite substantial advances in medical device surface modifications, no synthetic coatings have so far matched the native endothelium as the optimal hemocompatible surface for blood-contacting implants. A promising strategy for rapid restoration of the endothelium on blood-contacting biomedical devices entails attracting circulating endothelial cells or their progenitors, via immobilized cell-capture molecules; for example, anti-CD34 antibody to attract CD34+ endothelial colony-forming cells (ECFCs). Inherent is the assumption that the cells attracted to the biomaterial surface are bound exclusively via a specific CD34 binding. However, serum proteins might adsorb in-between or on the top of antibody molecules and attract ECFCs via other binding mechanisms. Here, we studied whether a surface with immobilized anti-CD34 antibodies attracts ECFCs via a specific CD34 binding or a nonspecific (non-CD34) binding. To minimize serum protein adsorption, a fouling-resistant layer of hyperbranched polyglycerol (HPG) was used as a "blank slate," onto which anti-CD34 antibodies were immobilized via aldehyde-amine coupling reaction after oxidation of terminal diols to aldehydes. An isotype antibody, mIgG1, was surface-immobilized analogously and was used as the control for antigen-binding specificity. Cell binding was also measured on the HPG hydrogel layer before and after oxidation. The surface analysis methods, x-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry, were used to verify the intended surface chemistries and revealed that the surface coverage of antibodies was sparse, yet the anti-CD34 antibody grafted surface-bound ECFCs very effectively. Moreover, it still captured the ECFCs after BSA passivation. However, cells also attached to oxidized HPG and immobilized mIgG1, though in much lower amounts. While our results confirm the effectiveness of attracting ECFCs via surface-bound anti-CD34 antibodies, our observation of a nonspecific binding component highlights the importance of considering its consequences in future studies.
期刊介绍:
Biointerphases emphasizes quantitative characterization of biomaterials and biological interfaces. As an interdisciplinary journal, a strong foundation of chemistry, physics, biology, engineering, theory, and/or modelling is incorporated into originated articles, reviews, and opinionated essays. In addition to regular submissions, the journal regularly features In Focus sections, targeted on specific topics and edited by experts in the field. Biointerphases is an international journal with excellence in scientific peer-review. Biointerphases is indexed in PubMed and the Science Citation Index (Clarivate Analytics). Accepted papers appear online immediately after proof processing and are uploaded to key citation sources daily. The journal is based on a mixed subscription and open-access model: Typically, authors can publish without any page charges but if the authors wish to publish open access, they can do so for a modest fee.
Topics include:
bio-surface modification
nano-bio interface
protein-surface interactions
cell-surface interactions
in vivo and in vitro systems
biofilms / biofouling
biosensors / biodiagnostics
bio on a chip
coatings
interface spectroscopy
biotribology / biorheology
molecular recognition
ambient diagnostic methods
interface modelling
adhesion phenomena.