Accelerated Endothelialization of Nanofibrous Scaffolds for Biomimetic Cardiovascular Implants

Abstract

Nanofiber nonwovens are highly promising to serve as biomimetic scaffolds for pioneering cardiac implants such as drug-eluting stent systems or heart valve prosthetics. For successful implant integration, rapid and homogeneous endothelialization is of utmost importance as it forms a hemocompatible surface. This study aims at physicochemical and biological evaluation of various electrospun polymer scaffolds, made of FDA approved medical-grade plastics. Human endothelial cells (EA.hy926) were examined for cell attachment, morphology, viability, as well as actin and PECAM 1 expression. The appraisal of the untreated poly-L-lactide (PLLA L210), poly-ε-caprolactone (PCL) and polyamide-6 (PA-6) nonwovens shows that the hydrophilicity (water contact angle > 80°) and surface free energy (<60 mN/m) is mostly insufficient for rapid cell colonization. Therefore, modification of the surface tension of nonpolar polymer scaffolds by plasma energy was initiated, leading to more than 60% increased wettability and improved colonization. Additionally, NH3-plasma surface functionalization resulted in a more physiological localization of cell–cell contact markers, promoting endothelialization on all polymeric surfaces, while fiber diameter remained unaltered. Our data indicates that hydrophobic nonwovens are often insufficient to mimic the native extracellular matrix but also that they can be easily adapted by targeted post-processing steps such as plasma treatment. The results achieved increase the understanding of cell–implant interactions of nanostructured polymer-based biomaterial surfaces in blood contact while also advocating for plasma technology to increase the surface energy of nonpolar biostable, as well as biodegradable polymer scaffolds. Thus, we highlight the potential of plasma-activated electrospun polymer scaffolds for the development of advanced cardiac implants.

A Vascular Graft On‐a‐Chip Platform for Assessing the Thrombogenicity of Vascular Prosthesis and Coatings with Tuneable Flow and Surface Conditions

“…This finding was unexpected and could be further investigated with the addition of other EC markers such as P‐selection that may reveal the antithrombogenic property of ECs in real‐time. ZO‐1 or PECAM‐1 [ 64 ] could also be applied in Figure 3a to confirm the presence of a confluent EC layer observed on the CD34 LIS surface.…”

Recent Advances in Cell‐Based Nanotherapy for Cardiovascular Diseases

“…For instance, numerous surface engineering strategies have been developed to modify the surface of devices for rapid reendothelialization in CVD therapy. [215,216] Therapeutic drugs, gene, and proteins are also adopted to accelerate endothelialization process. [217,218] Besides, erythrocyte-mimicking nanovehicles (EM-NVs) and vascular grafts present an outstanding effect in vascular tissue engineering relying on rapid proliferation and migration of ECs.…”

Special Issue: “Polymer-Based Biomaterials and Tissue Engineering”

“…Studies [2][3][4][5] reported novel strategies for the development of biomaterials in the form of composites, hydrogels, or electrospun fibers for tissue engineering applications. Gł ąb et al [2] investigated the influence of collagen types on the physico-chemical properties of polyvinylpyrrolidone and poly(vinyl alcohol) composites that also included a ceramic phase (hydroxyapatite).…”

“…Murine stromal ST2 cells cultured in media with different dissolution products released from the scaffolds show a minor reduction in cell viability with an increase in VEFG release, which indicates that the composites are interesting for tissue engineering applications. In addition, Matschegewski et al [5] prepared electrospun scaffolds from FDA-approved commercial medical-grade polymers (PLA, polycaprolactone (PCL), and polyamide) to assess the physicochemical and biological evaluation of cardiac implants. Untreated and plasma-activated polymeric nonwovens were analyzed to evaluate their influence on endothelial cell response.…”