TY - JOUR

T1 - SiCxNyOz Coatings Enhance Endothelialization and Bactericidal activity and Reduce Blood Cell Activation

AU - Bhaskar, Nitu

AU - Sulyaeva, Veronica

AU - Gatapova, Elizaveta

AU - Kaichev, Vasilii

AU - Rogilo, Dmitry

AU - Khomyakov, Maxim

AU - Kosinova, Marina

AU - Basu, Bikramjit

N1 - Funding Information: The authors are grateful to Professor A.M. Korsunsky (University of Oxford) for useful discussion on the results of nanomechanical property measurements. The authors would like to acknowledge the help received from Krishnakath Sada in SEM imaging at the Centre for Nano Science and Engineering (CeNSE) at IISc. The authors are thankful to Dr. Kaushik Chatterjee (IISc) for providing the help during cell culture experiments. AFM investigations were performed using the equipment of CKP “Nanostruktury” (ISP SB RAS) and were supported by the Ministry of Science and Higher Education of the Russian Federation (project number 0306-2019-0011). N.B. is thankful to the Department of Science and Technology for providing financial support for her research work under Women Scientist Scheme A (SR/WOS-A/LS-513/2017). The authors are grateful to the Department of Science and Technology (Govt. of India) and the Russian Foundation for Basic Research for funding this research work under the framework of the joint BRICS project DST no. DST/IMRCD/BRICS/PilotCall2/SCBCPCVD/2018(G) and RFBR no. 18-53-80016, respectively. Publisher Copyright: Copyright © 2020 American Chemical Society. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/10/12

Y1 - 2020/10/12

N2 - For biomedical applications, a number of ceramic coatings have been investigated, but the interactions with the components of living system remain unexplored for oxycarbonitride coatings. While addressing this aspect, the present study aims to provide an understanding of the biocompatibility of novel SiCxNyOz coatings that could validate the hypothesis that such coatings may not only enhance the cell-material interaction by re-endothelialization but also can help to reduce bacterial adhesion and activation of blood cells. This work reports the physicochemical properties, hemocompatibility, endothelialization, and antibacterial properties of novel amorphous SiCxNyOz coatings deposited on commercial pure titanium (Ti) by radiofrequency (RF) magnetron sputtering at varied nitrogen (N2) flow rates. A comparison is made with diamond-like carbon (DLC) coatings, which are clinically used. The surface roughness, surface wettability, nanoscale hardness, and surface energy of SiCxNyOz coatings were found to be dependent on the nitrogen (N2) flow rate. Importantly, the as-deposited SiCxNyOz coatings exhibited much better nanoscale hardness and scratch resistance than DLC coatings. Furthermore, Raman spectroscopy analysis of the SiCxNyOz coating deposited on Ti showed a change in the graphitic/disordered carbon content. Cytocompatibility and hemocompatibility properties of the as-deposited SiCxNyOz coating were evaluated using the Mus musculus lymphoid endothelial cell line (SVEC4-10) and rabbit blood in vitro. WST-1 assay analysis showed that these coatings, when compared to DLC, exhibited a better proliferation of endothelial cells, which can potentially result in improved surface endothelialization. Furthermore, qualitative and quantitative analyses of immunofluorescence images revealed a dense cellular layer of SVEC4-10 on SiCxNyOz coatings, deposited at 15 and 30 sccm nitrogen flow rates. As far as compatibility with rabbit blood is concerned, the hemolysis of the SiCxNyOz coatings was less than 4%, with slightly lower values for coatings deposited without N2 flow. The SiCxNyOz coatings support less platelet adhesion and aggregation, with no signature of morphological deformation, as compared to the uncoated titanium substrate or DLC coatings. Furthermore, SiCxNyOz coatings were also found to be effectively extending the blood coagulation time for a period of 60 min. The antimicrobial study of as-deposited SiCxNyOz coatings on E. coli and S. aureus bacteria revealed the effective inhibition of bacterial proliferation after 24 h of culture. An attempt has been made to explain the cyto- A nd hemocompatibility properties with antimicrobial efficacy of coatings in terms of the variation in the coating composition and surface energy. Taken together, we conclude that SiC1.3N0.76O0.87 coating having a roughness of 17 nm and a surface free energy of 54.0 ± 0.7 mN/m can exhibit the best combination of hardness, elastic modulus, scratch resistance, cytocompatibility, hemocompatibility, and bactericidal properties.

AB - For biomedical applications, a number of ceramic coatings have been investigated, but the interactions with the components of living system remain unexplored for oxycarbonitride coatings. While addressing this aspect, the present study aims to provide an understanding of the biocompatibility of novel SiCxNyOz coatings that could validate the hypothesis that such coatings may not only enhance the cell-material interaction by re-endothelialization but also can help to reduce bacterial adhesion and activation of blood cells. This work reports the physicochemical properties, hemocompatibility, endothelialization, and antibacterial properties of novel amorphous SiCxNyOz coatings deposited on commercial pure titanium (Ti) by radiofrequency (RF) magnetron sputtering at varied nitrogen (N2) flow rates. A comparison is made with diamond-like carbon (DLC) coatings, which are clinically used. The surface roughness, surface wettability, nanoscale hardness, and surface energy of SiCxNyOz coatings were found to be dependent on the nitrogen (N2) flow rate. Importantly, the as-deposited SiCxNyOz coatings exhibited much better nanoscale hardness and scratch resistance than DLC coatings. Furthermore, Raman spectroscopy analysis of the SiCxNyOz coating deposited on Ti showed a change in the graphitic/disordered carbon content. Cytocompatibility and hemocompatibility properties of the as-deposited SiCxNyOz coating were evaluated using the Mus musculus lymphoid endothelial cell line (SVEC4-10) and rabbit blood in vitro. WST-1 assay analysis showed that these coatings, when compared to DLC, exhibited a better proliferation of endothelial cells, which can potentially result in improved surface endothelialization. Furthermore, qualitative and quantitative analyses of immunofluorescence images revealed a dense cellular layer of SVEC4-10 on SiCxNyOz coatings, deposited at 15 and 30 sccm nitrogen flow rates. As far as compatibility with rabbit blood is concerned, the hemolysis of the SiCxNyOz coatings was less than 4%, with slightly lower values for coatings deposited without N2 flow. The SiCxNyOz coatings support less platelet adhesion and aggregation, with no signature of morphological deformation, as compared to the uncoated titanium substrate or DLC coatings. Furthermore, SiCxNyOz coatings were also found to be effectively extending the blood coagulation time for a period of 60 min. The antimicrobial study of as-deposited SiCxNyOz coatings on E. coli and S. aureus bacteria revealed the effective inhibition of bacterial proliferation after 24 h of culture. An attempt has been made to explain the cyto- A nd hemocompatibility properties with antimicrobial efficacy of coatings in terms of the variation in the coating composition and surface energy. Taken together, we conclude that SiC1.3N0.76O0.87 coating having a roughness of 17 nm and a surface free energy of 54.0 ± 0.7 mN/m can exhibit the best combination of hardness, elastic modulus, scratch resistance, cytocompatibility, hemocompatibility, and bactericidal properties.

KW - antibacterial

KW - cytocompatibility

KW - SiCNO, hemocompatibility

KW - titanium coatings

UR - http://www.scopus.com/inward/record.url?scp=85095434157&partnerID=8YFLogxK

U2 - 10.1021/acsbiomaterials.0c00472

DO - 10.1021/acsbiomaterials.0c00472

M3 - Article

C2 - 33320557

AN - SCOPUS:85095434157

VL - 6

SP - 5571

EP - 5587

JO - ACS Biomaterials Science & Engineering

JF - ACS Biomaterials Science & Engineering

SN - 2373-9878

IS - 10

ER -