Mussel adhesive protein fused with VE-cadherin domain specifically triggers endothelial cell adhesion

Cadmium-induced dysfunction of the blood-brain barrier depends on ROS-mediated inhibition of PTPase activity in zebrafish

Increasing evidence has demonstrated that cadmium accumulation in the blood increases the risk of neurological diseases. However, how cadmium breaks through the blood-brain barrier (BBB) and is transferred from the blood circulation into the central nervous system is still unclear. In this study, we examined the toxic effect of cadmium chloride (CdCl₂) on the development and function of BBB in zebrafish. CdCl₂ exposure induced cerebral hemorrhage, increased BBB permeability and promoted abnormal vascular formation by promoting VEGF production in zebrafish brain. Furthermore, in vivo and in vitro experiments showed that CdCl₂ altered cell-cell junctional morphology by disrupting the proper localization of VE-cadherin and ZO-1. The potential mechanism involved in the inhibition of protein tyrosine phosphatase (PTPase) mediated by cadmium-induced ROS was confirmed with diphenylene iodonium (DPI), a ROS production inhibitor. Together, these data indicate that BBB is a critical target of cadmium toxicity and provide in vivo etiological evidence of cadmium-induced neurovascular disease in a zebrafish BBB model.

Endothelial Cell Responses to a Highly Deformable Titanium Alloy Designed for Vascular Stent Applications

Titanium alloys are widely used for biomedical applications due to their good biocompatibility. Nevertheless, they cannot be used for balloon expandable stents due to a lack of ductility compared to cobalt-chromium (Co-Cr) alloys and stainless steels. In this study, a new highly deformable Ti-16Nb-8Mo alloy was designed for such an application. However, the biological performance of a stent material is strongly influenced by the effect exerted on the behavior of endothelial cells. Therefore, the cellular responses of human umbilical vein endothelial cells (HUVECs), including morphological characteristics, cell viability and proliferation, and functional markers expression, were investigated to evaluate the biocompatibility of the alloy in the present study. The in vitro results demonstrated the suitability of this alloy for use as endovascular stents.

Advances in biomolecule inspired polymeric material decorated interfaces for biological applications

With the development of surface modification technology, interface properties have great effects on the interaction between biomedical materials and cells and biomolecules, which significantly affects the biocompatibility and functionality of materials. As an orderly and perfect system, biological organisms in nature effectively integrate all kinds of bio-interfaces with physiological functions, which shed light on the importance of biomolecules in organisms. It gives birth to a bio-inspiration strategy to design and fabricate smart materials with specific functionalities, e.g. osteogenic and chondrocytic induced materials inspired by bone sialoprotein and chondroitin sulfate. Through this mimicking approach, various functional materials were utilized to decorate the interfaces and further optimize the performance of biomedical materials, which would widely expand their applications. In this review, followed by a summary and brief introduction of surface modification methods, we highlight recent advances in the fabrication of functional polymeric materials inspired by a range of biomolecules for decorating interfaces. Then, the other applications of biomolecule inspired materials including tissue engineering, diagnosis and treatment of diseases and physiological function regulation are presented and the future outlook is discussed as well.

Covalent immobilization of biomolecules on stent materials through mussel adhesive protein coating to form biofunctional films

It is widely accepted that surface biofunctional modification may be an effective approach to improve biocompatibility and confer new bioactive properties on biomaterials. In this work, mussel adhesive protein (MAP) was applied as a coating on 316 L stainless steel substrates (316 L SS) and stents, and then either immobilized VEGF or CD34 antibody were added to create biofunctional films. The properties of the MAP coating were characterized by scanning electron microscope (SEM), atomic force microscope (AFM) and a water contact angle test. Universal tensile testing showed that the MAP coating has adequate adhesion strength on a 316 L stainless steel material surface. Subsequent cytotoxicity and hemolysis rate tests showed that the MAP coatings have good biocompatibility. Moreover, using N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysulfosussinimide (EDC/NHS) chemistry, VEGF and CD34 antibody were immobilized on the MAP coatings. The amount and immobilized yield of VEGF on the MAP coatings were analyzed by enzyme-linked immuno-assays (ELISA). Finally, an endothelial cells culture showed that the VEGF biofunctional film can promote the viability and proliferation of endothelial cells. An in vitro CD34⁺ cells capturing test also verified the bioactive properties of the CD34 antibody coated stents. These results showed that the MAP coatings allowed effective biomolecule immobilization, providing a promising platform for vascular device modification.

Mussel adhesive protein fused with VE-cadherin extracellular domain promotes endothelial-cell tight junctions and in vivo endothelization recovery of vascular stent

Improving the surface properties of vascular stents to accelerate endothelialization in vivo could play an important role in minimizing the risk of late thrombosis. We previously showed that mussel adhesive protein fused with VE-cadherin extracellular domain (VE-M) specifically triggered endothelial cell adhesion in vitro. In this study, using stent implants coated with VE-M, we evaluated the clinical applicability of VE-M in endothelialization recovery in vivo. First, we explored the effect of VE-M on hemocompatibility and tight junctions between endothelial cells (ECs) in vitro. VE-M significantly inhibited platelet adhesion and promoted EC proliferation. Furthermore, VE-M drastically increased the centralization of F-actin in human umbilical vein endothelial cells (HUVECs) along the cell contacts, reduced fluorescein isothiocyanate (FITC)-dextran transport across the HUVECs, and elevated expression levels of tight junction proteins (TJPs) in ECs. We then evaluated the effect of VE-M on endothelialization recovery in vivo through implantation of vascular stents. At 1 day after implantation, stents coated with VE-M recruited more endothelial progenitor cells (EPCs) than bare stents. At 7 days after implantation, VE-M stents had a greater coverage of ECs than bare stents. At 1 month after implantation, ECs on VE-M stents were appropriately elliptical in morphology and closely resembled physiological morphology. Hematoxylin-eosin (HE) staining revealed little in-stent neointima formation on VE-M stents, and SEM images revealed that smooth endothelium had formed on VE-M stents without adherent platelets. Taken together, these findings indicate that VE-M accelerates in vivo endothelialization of vascular stents via recruitment of EPCs and promotes endothelium formation and could be explored as a potential bioactive coating for vascular implant. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:94-103, 2020.