Combinational Biomimicking of Lotus Leaf, Mussel, and Sandcastle

Subscriber access provided by MIDWESTERN UNIVERSITY

Biological and Medical Applications of Materials and Interfaces

Combinational Biomimicking Lotus Leaf, Mussel, and Sandcastle Worm for Robust Superhydrophobic Surfaces with Biomedical Multifunctionality: Antithrombotic, Antibiofouling, and Tissue-Closure Capabilities Kiduk Han, Tae Yoon Park, Kijung Yong, and Hyung Joon Cha ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.8b21122 • Publication Date (Web): 20 Feb 2019 Downloaded from http://pubs.acs.org on February 23, 2019

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Materials & Interfaces

Combinational Biomimicking Lotus Leaf, Mussel, and Sandcastle Worm for Robust Superhydrophobic Surfaces with Biomedical Multifunctionality: Antithrombotic, Antibiofouling, and Tissue-Closure Capabilities

Kiduk Han,‡ Tae Yoon Park,‡ Kijung Yong,* and Hyung Joon Cha*

Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 37673, Korea

‡These

authors contributed equally to this work

*E-mail: [email protected], [email protected]

KEYWORDS: superhydrophobic surface, mussel adhesive protein, antithrombotic catheter, antibiofouling, biocompatible tissue closure

ACS Paragon Plus Environment

ACS Applied Materials & Interfaces 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ABSTRACT The surface wetting occurring in daily life causes undesired contaminations, which are critical issues in various fields. To solve these problems, the nonwetting property of a superhydrophobic (SH) surface has proven its utility by preventing contaminant infiltration, serious infections, or malfunction. However, applying SH surfaces in the biomedical field has been limited due to the weak durability and toxicity of the related components. To overcome these limitations, we developed a robust and biocompatible SH surface through combinational biomimicking of three natural organisms: lotus leaf, mussel, and sandcastle worm, for the first time. Using the water-immiscible and polycationic characteristics of mussel adhesive protein adhesive (iMglue), a SH iMglue-SiO2(TiO2/SiO2)2 coating was fabricated by solution-based electrical charge-controlled layer-by-layer (ECLbL) growth of nanoparticles (NPs). The fabricated iMglue-SiO2(TiO2/SiO2)2 SH surface showed excellent durable nonwetting properties, and was applied to an intracatheter tube coating to develop antithrombotic catheters under blood flow. Furthermore, we developed a iMglue-employed SH patch for a tissue closure bandage by spraying hydrophobic SiO2 NPs on the iMglue-covered cotton pads. The prepared iMglue-employed SH patch showed perfect bifunctionality with excellent antibiofouling and tissue closure capabilities. Our work presents a novel, useful strategy for fabricating a biomedically multifunctional and robust SH surface through combinational mimicking of natural organisms.

2


Page 2 of 27

Page 3 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


1. INTRODUCTION A superhydrophobic (SH) surface inspired by the lotus leaf has been studied in various fields, such as self-cleaning,1 humidity proofing,2 oil-water separation,3-7 antifouling, and anticorrosion,8-10 due to its special nonwetting property with high water contact angle (≥ 150°) and a low adhesive force for liquids. Among these applications, the anti-wetting property, as well as the antibiofilm11, 12 and antibacterial13, 14 capabilities, which are due to its low adhesion to contaminant biomolecules caused by the inherent air pocket on the SH surface, has drawn attention in the biomedical field. On normal surfaces, the adsorption of microorganisms or body fluids, including proteins and blood, can cause serious problems in the human body. Continuous bacterial attachment forms a biofilm that releases toxic substances leading to chronic infections.11 In addition, medical devices, such as artificial vascular prostheses, are faced with unintentional blood clotting and abnormal adhesion and fibrosis induced by external material transplantation. For these reasons, antibacterials, antithrombotics, and antiadhesives made of SH surface for the biomedical field have become important in developing medical devices.15, 16 In this regard, the antibacterial effect of the air pocket of SH surface compared to glass slides, polyurethane, and white polystyrene sheets has been reported; SH surface showed an exceptional antibacterial ability to Staphylococcus aureus and Escherichia coli after 1 h exposure to a bacterial suspension.17 The effect of metallic implant wettability change (superhydrophilicity to superhydrophobicity) on platelet adhesion was also analyzed, and SH implants showed the lowest platelet adhesion, indicating the antithrombotic potential of SH surfaces.18 Although various attempts have been made for SH surface-driven antibiofouling, its application to biomedical devices has been hindered due to the weak durability of SH surface. A typical SH surface quickly loses its antibiofouling characteristics because its micro/nanostructures are easily damaged even with a slight impact. Thus, various strategies have been explored to improve its durability,19-21 and in particular the chemical adhesive3



grafted SH surface has made great leaps in this area. Representatively, it was shown that the robustness of an SH surface was drastically enhanced by spraying perfluorosilane-coated titanium dioxide (TiO2) nanoparticles (NPs) on the commercial organic spray-adhesive.1 Following this research, it was reported that an inorganic adhesive allowed the production of a durable underwater superoleophobic surface, which was prepared by spray coating of TiO2 NPs and adhesive mixtures.22 However, the hazards of the chemical adhesives impose critical drawbacks to the application in biomedical fields. For these reasons, the development of nonhazardous and biocompatible adhesives for fabricating highly durable SH surfaces deserves consideration in biomedical applications. In addition, most of the SH surface fabrication methods using organic or inorganic adhesives have exclusively employed a spray coating, limiting its application to various structures, such as tube and fine holes. Thus, to obtain a conformal, uniform coating on various surface structures, a layer-controlled growth method is highly desirable. A promising candidate for layered deposition is electrical charge-controlled layer-by-layer (ECLbL) growth.23 For the biocompatible, water-immiscible, and charge-carried adhesive for ECLbL fabrication of SH surface, we employed underwater natural organisms, especially mussels and sandcastle worms, which secrete strong underwater adhesives.24, 25 Mussel adhesive protein (MAP), which holds the mussel onto various underwater surfaces, is an attractive adhesive in biomedical engineering due to its superior underwater adhesion and biocompatibility.24, 26, 27 In addition, the immiscible property was inspired by the immiscible modality of sandcastle worms secreting a condensed and sticky adhesive associated with oppositely charged polyelectrolytes.28, 29 Although there have been attempts to fabricate SH surfaces from adhesive moieties derived from MAP,30-32 the SH surface products could not be applied to the biomedical field due to the toxicity of the adhesive reactants and uneven adhesive coatings because of nonselective adsorption and hydrophobic NP agglomeration in the gravitational direction. Herein, by combining the characteristics of three natural species, lotus leaf, mussel, and 4


Page 4 of 27

Page 5 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


sandcastle worm, a biocompatible and robust SH surface was synthesized and demonstrated for coating on various 3-dimensional (3D) structured surfaces. The synergistic effects of the intrinsic material properties (underwater adhesion and positive charge) of the MAP and the physiochemical properties of the immiscible modality from sandcastle worms were feasible for applying ECLbL growth to provide electrostatic attraction-driven layer growth of the immiscible MAP adhesive (iMglue) and silicon dioxide (SiO2) and TiO2 NPs. The iMglueECLbL-prepared highly robust SiO2(TiO2/SiO2)2 coating was applied to coat intracatheter tubes to provide an antithrombotic function. Due to the robust SH thin layers derived from adhesiveness of iMglue, blood clotting was perfectly prohibited in the intracatheter tube while maintaining its nonwetting property with continuous blood flow. In addition to its adhesive properties for antibiofouling SH surface fabrication, iMglue has additional but very important functions in tissue closure. Inspired by this dual functionality of iMglue, we fabricated a robust SH patch, which possesses both antibiofouling and biocompatible tissue closure characteristics, by simply spraying the hydrophobic SiO2 NPs onto the iMglue-covered patch. The biocompatible tissue closure capacity of the iMglue-employed superhydrophobic patch (SH/iMglue patch) was significantly higher than that of the control group as measured by the peel adhesion test. In addition, it showed superior durability and antifouling ability compared with the general SH spray coating even in harsh environments where external stress was applied for an hour and was exposed to blood-pouring conditions. A key, overall concept of the current work is summarized in Figure 1 for robust and multifunctional SH surface fabricated by iMglue: antithrombotic, antibiofouling and biocompatible tissue-closure.

2. RESULTS AND DISCUSSION ECLbL growth of SH surface was processed using the electrostatic attraction between NPs and interfacial charged layers modifying the substrate surface.33, 34 The SiO2 and TiO2 NPs were 5



employed as negatively35 and positively36, 37 charged NPs, respectively. As interfacial charge layers, three types of modifiers were tested to provide positive surface charge and strengthen the adhesion to the substrate, including amino silane (AS), poly(diallyldimethyl ammonium chloride) (PDDA), and iMglue. We found that all charge layer-coated surfaces showed hydrophilicity ( 50°) by water contact angle analyses (Figure S1, Supporting Information). Based on these materials, SH SiO2(TiO2/SiO2)2 ECLbL surfaces were fabricated by three different routes, as shown in Figure 2a. First, the positively charged layers (AS, PDDA, and iMglue) were coated on the substrate using methods appropriate for each material (detailed descriptions are provided in the experimental section). Subsequently, negatively charged SiO2 NPs were evenly deposited on positively charged interfacial layers (Figure 2a(ⅰ)). In the following step, positively charged TiO2 NPs were coated on the SiO2 NP layer (Figure 2a(ⅱ)). Additional SiO2 NPs were coated on the TiO2/SiO2-coated surface to form a SiO2(TiO2/SiO2)1 thin coating (Figure 2a(ⅲ)). An SiO2(TiO2/SiO2)2 thin coating was produced by repeating these steps 2 times (Figure 2a(ⅱ and ⅲ)). It was found that the SiO2(TiO2/SiO2)2 thin coating provided sufficient roughness for superhydrophobicity with the lowering of the surface energy by chemisorption of silane self-assembled monolayers (SAM). In the case of AS and PDDA charge layers, roughness (Ra) values of SiO2(TiO2/SiO2)2 thin coatings were 49.6 nm and 49.3 nm, respectively (Figure S2, Supporting Information). However, SiO2(TiO2/SiO2)2 thin coating synthesized using iMglue showed significantly larger roughness (222.0 nm) due to much higher NP agglomeration. All three samples of the SiO2(TiO2/SiO2)2 thin coating synthesized using AS, PDDA, and iMglue charge layers exhibited superhydrophobicity with water contact angles of 156.1 ± 1.1°, 163.5 ± 3.1°, and 154.8 ± 0.8°, respectively (Figure 2b). Additionally, they showed stable antiwetting properties of impacting water droplets in dynamic conditions without adhering to the surface irrespective of the interfacial charge layer (Figure 2c). This result indicates that the SH

6


Page 6 of 27

Page 7 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


SiO2(TiO2/SiO2)2 coatings strongly repel the water-soluble pollutants and have a strong antibiofouling capability. In addition, the surface morphology of the SH SiO2(TiO2/SiO2)2 thin coatings significantly relied on the interfacial charge layer. A relatively thin coating with less NP aggregation was found on the AS-SiO2(TiO2/SiO2)2 coating (Figure 2d) because NP deposition was solely directed by the electrostatic attraction between the NPs and AS molecules. However, when PDDA was applied, in addition to the NPs-PDDA electrostatic attraction of, additional interactions caused slightly increased agglomeration of NPs (Figure 2e).38 This phenomenon of NP agglomeration was most pronounced when iMglue was used as a charge layer (Figure 2f and g) due to its high positive surface charge density derived from lysine amino acid residues, which was measured by zeta potential analyses (Figure S3, Supporting Information). Because the superhydrophobicities were also found on SiO2(TiO2/SiO2)2 thin coatings made of AS and PDDA, we enlarged scanning electron microscope (SEM) image of each surface structure and observed that all coated surfaces have nano/micro-sized protrusions (Figure S4, Supporting Information). It was also confirmed that SiO2 and TiO2 NPs were deposited on all the surfaces regardless of charge layer types through observation of the presence of Si and Ti elements by energy dispersive spectrometer (EDS) analyses (Figure S5, Supporting Information). However, a protein element N was found only on the surface with iMglue. Based on the zeta potential analyses of PDDA and the iMglue at the same concentration, the net positive charge of iMglue (1.76 ± 0.38 mV) was approximately 2.67-fold stronger than that of PDDA (0.66 ± 0.16 mV). A higher positive charge causes the recruitment of more NPs due to strong charge interactions, producing more agglomerates. In addition, L-3,4dihydroxyphenylalanine (DOPA) with a bidentate hydroxyl group, a dominant functional amino acid residue in MAP, recruited NP agglomerates, resulting in a much thicker (~1923times) SiO2(TiO2/SiO2)2 coating compared to those of AS and PDDA, which was clearly observed by SEM analyses of cross-sectional coatings (Figure S6, Supporting Information). 7



The synergistic effect of positive charge and DOPA residues enabled the rapid and efficient fabrication of SH surface on the substrate. The mechanical durability of the SH coatings is essential for practical applications. To measure the mechanical durability of the SH SiO2(TiO2/SiO2)2 thin coatings, a tape abrasion test was conducted (Figure 3a). The durability of the coatings for three different samples was compared by measuring the water contact angles of the coatings after each tape abrasion cycle (Figure 3b). Both AS and PDDA samples showed that the water contact angles drop to ~134° even after the first abrasion cycle. With repetition of the abrasion test over five cycles, almost all the NPs were detached (Figure S7, Supporting Information), which gives a water contact angle substantially similar to that of the perfluoroalkyl silane-modified bare glass surface (~120°).39 On the other hand, the iMglue-SiO2(TiO2/SiO2)2 coating retained water contact angles greater than ~150° after five abrasion cycles. Even after under 10 abrasion cycles, the thin coating maintained high water contact angle of ~144°. This robust durability of the iMglue is attributed to the synergetic effects of the water immiscibility and strong adhesiveness derived from the sandcastle worms and mussels, respectively. The iMglue’s water-immiscibility enabled a thin, even coating of NPs on substrate in the dip solution coating process. The adhesion property derived from DOPA and the lysine residues of the MAP ensured conformal coating on various substrate surfaces, including metal, glass, and latex.26, 40, 41 In addition, the positive charge and adhesiveness of DOPA facilely recruit NP adsorption with strong attachment. Furthermore, the iMglue does not require any pretreatments, while AS and PDDA charge layers need a series of constraints to introduce surface charges.34, 42 Our ECLbL-prepared SH iMglue-SiO2(TiO2/SiO2)2 coating was highly useful for an antithrombotic catheter application because of its highly durable nonwetting and antibiofouling properties. Additionally, the ECLbL-dip coating is very facile for conformal coating of the inner tubular structure, which is very difficult with conventional spray coatings. For comparison of the antithrombotic properties, three different samples were prepared: bare, iMglue only-coated, 8


Page 8 of 27

Page 9 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


and iMglue-SiO2(TiO2/SiO2)2-coated (SH/iMglue) catheters. Because the catheter surface made of latex rubber is neutrally charged, it does not affect the charge layer deposition. The final concentration of 0.01 M CaCl2 was added for rapid blood thrombi formation based on an intrinsic blood coagulation mechanism,43 and blood thrombi on the wall of the catheter were observed with blood flowing into the catheter. According to our test results (Figure 3c), thrombosis occurred in the bare and sole iMglue-coated catheters, but it was not detected in the SH/iMglue catheter. The antithrombotic property of the SH/iMglue derived from a hydrodynamic effect that makes it difficult for blood, especially platelets, to attach onto the wall due to a decrease in the effective area exposed to blood and a reduction of bioactive blood components associated with blood clotting.43 The Cassie state of the stable nanostructure formed by the iMglue-SiO2(TiO2/SiO2)2 coating makes the air pocket trapped at the interface between the solid surface and the liquid, allowing the blood to have a fast shear rate at the SH surface. In this context, bare and iMglue only catheters, which have no air pockets, lead to high local gradients in the shear rate of the blood flow and a low shear rate on the surface, where blood coagulation is well formed in the low-shear rate zone.44 In addition, SH/iMglue could maintain the SH surface even after shear stress from flowing blood. Although the inner diameter of the catheter was only 2.5 mm, the NPs were nicely dispersed and attached on the inner wall of the catheter by the ECLbL process. The distribution of the NPs inside of catheter after blood flow was investigated by SEM analysis (Figure S8, Supporting Information). Numerous NPs were well distributed and attached on the inner wall of SH/iMglue catheter, indicating effective persistency of the SH surface even after blood flow. In addition to the excellent antithrombotic properties of our SH/iMglue catheter, the biocompatibility of iMglue45, 46 is also essential for in vivo devices such as catheters. As a biomimicking adhesive for SH NP deposition, iMglue has another crucial functionality of tissue closure. The dual functionality of iMglue is well demonstrated by making SH patches for tissue closure bandages (Figure 4). iMglue was spread on both sides of the cotton 9



pad, followed by spraying hydrophobic SiO2 NPs only on the single face of the iMglue-coated pad (Figure 4a). The NP-attached upper face of the cotton pad showed a stable nonwetting SH property (Figure S9, Supporting Information). On the other hand, the bottom face of the patch with iMglue component played a role in a tissue closure bandage that permeates into the wound and induces wound closure. Due to this unique structure, our SH/iMglue patch has both antibiofouling and tissue closure functionalities. First, the wound closure ability of the iMglue for the SH/iMglue patch was measured by a peel adhesion test using ex vivo porcine incised skin tissue (Figure 4b). A 10  10 mm2 porcine skin with an 8 mm incision in the middle was prepared. The iMglue was applied between the incised tissue and cured tissue. The porcine skin without iMglue treatment was employed as a comparative control. Then, both skin samples were pulled at 1.8 mm min-1 using a universal testing machine. The adhesiveness of porcine skin treated with the iMglue on the injured area was ~26-times stronger than that of the untreated porcine skin, which demonstrated the wound closure potential of incised skin tissue by the iMglue. Previously, MAPs demonstrated their wound closure abilities with reduced scar formation.46,

47

Due to the strong adhesiveness of iMglue, it could be applied to sutureless

wound closure, allowing potential to apply into diverse soft tissues lacking collagenous structures. In addition, iMglue could promote wound closure biologically by improving cell viability,48 initial attachment, and proliferation,24, 49 which might be derived from synergetic effects of biocompatibility of two components (MAP and HA) and the adhesion ability of MAP. These features would facilitate closing wound. Second, we evaluated the antibiofouling properties of the SH/iMglue patch by measuring the antibacterial (Figure 4c) and blood-repellent (Figure 4d) abilities. The antibacterial ability of the SH part of SH/iMglue patch was examined from two aspects: biofilm formation of bacteria50 and destruction of the SH SiO2 surface by shear stress.51 The experimental groups consisted of the SH SiO2 patch with or without applying the iMglue. E. coli, a representative bacterium that is able to express green fluorescence protein (GFP) for easy visualization,52 was 10


Page 10 of 27

Page 11 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


employed. Based on the overall shape of the SH patch under bright field illumination, the degree of bacterial biofilm formation on the patch was determined by the green fluorescence emitting area under the green fluorescent field. The degree of destroyed SH surface was estimated with a SEM. Before being incubated in GFP-expressing E. coli solution, the SH patch without the iMglue showed sparsely formed SiO2 NPs along the cotton fiber, but the SH part of SH/iMglue patch exhibited densely formed NPs (Figure S10, Supporting Information). In the case of the SH SiO2-coated patch without the iMglue, bacterial biofilm formation was facilitated by surface destruction due to shear stress after the bacterial incubation time elapsed (Movie S1, Supporting Information), as identified by GFP fluorescence and SEM images. In contrast, the SH part of SH/iMglue patch was not contaminated at all after the 30 min incubation, and only a small biofilm was formed in the lost part of the iMglue coating after a 60 min incubation, which can be improved with a more conformal iMglue coating. Due to the SH coating of the outer face of the patch, the patch showed an excellent bloodrepellent property, which is one of the crucial factors for tissue closure bandages because tissue adhesion can be induced by whole blood coagulation.53 When internal organs are injured, bleeding tissues easily attach to the surrounding tissues, causing tissue adhesion because of the blood adhesiveness and innate coagulation processes. Blood is difficult to repel upon contact with other surfaces due to the activation of the hemostatic mechanism.54 Figure 4d compares bare and SH/iMglue patches for occasions of contact with blood microdroplets. The bare patch was fully soaked with blood, and blood contamination clearly remained underneath the patch, which can further infect the wounded skin. In contrast, SH/iMglue patch completely repelled the blood without any contamination remaining on the underlying skin (Figure 4d and Movie S2, Supporting Information). In this study, commercialized cotton was used for the bandage intermediate, but if biocompatible materials, such as collagen mesh, are utilized, our platform could also be successfully applied to defects of internal organs and possibly close the wound

11



without sutures, which clears up a concern about postoperative peritoneal tissue adhesion that may occur on the opposite side of the patch.

3. CONCLUSIONS Here, we developed a novel and robust SH surface by inspired by three organisms: lotus leaf, mussel, and sandcastle worm. The immiscible and positively charged iMglue, combining the benefits of mussel and sandcastle worms, easily recruited charged NPs to attach on various substrates in a surface-independent manner to have nano/micro-sized roughness topologies. The resultant ECLbL-driven SH iMglue-NP coating exhibited highly durable anti-wetting properties and showed great adhesion robustness against the tape abrasion test. Based on the multifunctionality and biocompatibility of our SH surface platform, we demonstrated its biomedical applications in an antithrombotic catheter and an antibiofouling tissue closure bandage for in vivo devices. The catheter treated with the uniform and even SH iMglueSiO2(TiO2/SiO2)2 coating inside the catheter tube perfectly prohibited blood coagulation under blood flow conditions, confirming its antithrombotic functionality. Additionally, the bifunctionality of the iMglue and the charge interlayer for the SH coating and tissue closure enabled the development of an SH patch for an antibiofouling and tissue closure bandage. It also has a feasible capability for curing internal organ incisions due to its adhesive, antibacterial, and blood-repellent properties. Collectively, the proposed novel and robust SH surface based on the characteristics of natural organisms fully demonstrated high potential for applications in developing in vivo biomedical devices.

12


Page 12 of 27

Page 13 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


4. EXPERIMENTAL SECTION Preparation of bioengineered MAP and an iMglue: Bioengineered MAP was produced in a bacterial expression system and purified as described previously.45, 55 The purified MAP was stored at -80 °C after freeze-drying. To prepare iMglue, freeze-dried MAP and hyaluronic acid (HA) (5 kDa; Lifecore Biomedical, Chaska, MN, USA) were dissolved in 100 mM sodium acetate buffer (pH 4; Sigma-Aldrich, St. Louis, MO, USA) to a concentration of 1 mg mL-1 and mixed at a mixing ratio (6:4 wt wt-1) of MAP and HA. After becoming turbid, iMglue was collected by centrifugation (100  g for 5 min). Charge layer deposition of AS, PDDA, and iMglue: Cleaned glass (76  26 mm; Duran, Wertheim,

Main,

Germany)

was

dipped

into

a

solution

comprising

3-

aminopropyl(diethoxy)methylsilane (97%; Sigma-Aldrich) and toluene (≥ 99.5%; Samchun, Pohang, Gyeongsangbuk-do, Korea) at a volume ratio of 1:99 for 30 min. For 20 min, the ASmodified glass was immersed in 0.1 M HCl (DaeJung, Siheung, Gyeonggi-do, Korea) for protonation. After that process, the surface charge of the glass became positive.42 To deposit PDDA (average Mw < 105, 35 wt % in H2O; Sigma-Aldrich) charge layer on the glass, the glass substrate was immersed in the PDDA solution for approximately 10 min and then washed for 2 min with distilled water (DW) to remove the residue.34 In the case of iMglue, 10 µL of iMglue was sprayed on the glass substrate (1 cm × 1 cm) and uniformly coated to a thickness of 20 µm using a doctor blade (Model 1401; Kipae, Suwon, Gyeonggi-do, Korea). Preparation of the SH SiO2(TiO2/SiO2)2 thin coating: 0.001% (wt vol-1) SiO2 NPs (1020 nm; Sigma-Aldrich) and TiO2 NPs (≥ 99.5%, 21 nm; Sigma-Aldrich) dissolved in DW were prepared. The AS-, PDDA- and iMglue-coated positive charge layers were dipped in the SiO2 NP solution for 10 min and rinsed with DW. Subsequently, the coated glass was immersed in a TiO2 NP solution for 10 min and rinsed with DE for removing impurities, followed by an additional SiO2 coating for 10 min. These processes produced a SiO2(TiO2/SiO2)1 thin coating surface. In this way, a SiO2(TiO2/SiO2)2 (n ≥ 2) thin coating was formed on the surface by 13



alternately repeating the process of dipping and cleaning the substrate with SiO2 and TiO2 NP solutions. Finally, the coated substrate and a vial containing 1 mL of trichloro(1H,1H,2H,2Hperfluorooctyl) silane (97%; Sigma-Aldrich) were placed in a desiccator filled with a silica gel for 3 h to lower the surface energy of the coating. To increase the vapor pressure of trichloro(1H,1H,2H,2H-perfluorooctyl)silane, the desiccator was evacuated for a few min every 30 min.34 Tape abrasion test: A commercially available tape (Cat. # 583D, 18 mm  30 m; 3M, Saint Paul, MN, USA) was fully attached by hand on the SH SiO2(TiO2/SiO2)2 thin coating synthesized using each charge layer. Then, the tape adhered on the surface was completely peeled off by hand at 2 mm s-1 to damage the deposited NPs. We designated this process as one cycle of the tape abrasion test and the process was repeated 10 times with measurement of water contact angle at every repeat to confirm the degree of surface damage. Zeta potential measurement: To measure the surface charge of each polymer, PDDA, iMglue, and iMglue were dissolved in 100 mM sodium acetate buffer (pH 4) at the same concentration of 0.05% (wt vol-1). Sodium nitrate (Sigma-Aldrich) was added to the polymer solution to a final concentration of 10 mM. The zeta potential was measured using a Zetapotential and particle analyzer (ELSZ-2000; Otsuka, Hirakata, Osaka, Japan) according to the manufacturer's protocol. Fabrication of the antithrombotic catheter and the blood clotting experiment: 3 cm long latex catheters (Sewoon Medical, Cheonan, Chungcheongnam-do, Korea) were coated by iMglue and dipped in SiO2 and TiO2 NP solutions dissolved in DW alternately for 10 min 3 and 2 times, respectively (SH/iM glue catheter). The unbound nanoparticles between each dipping procedure were thoroughly rinsed with DW. As comparative controls, bare and sole iMglue only coated catheters were employed. The bare catheter was the SiO2(TiO2/SiO2)2 thin coating catheter without iMglue in the same manner, and the thrombotic property of the catheter coated with iMglue without thin coating processes was compared with other catheters. Blood (Korea 14


Page 14 of 27

Page 15 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Animal Blood Bank, Sokcho, Gangwon-do, Korea) mixed with CaCl2 at a final concentration of 0.01 M was flowed into the catheter using a 5 mL syringe at a flow rate of 0.25 mL min-1 for 10 min. The addition of a small amount of CaCl2 is intended to induce blood clotting. After flowing blood, unclogged blood was pumped out by introducing air at the same rate. Clogged blood in the catheter was fixed with 0.1% glutaraldehyde solution (Sigma-Aldrich). Preparation of the hydrophobic SiO2 suspension: 40 mL of 0.05% (wt vol-1) SiO2 nanoparticles (1020 nm; Sigma-Aldrich) suspended in dehydrated toluene (99.5%; Samchun) are transferred in a Schlenk flask and added with 1 mL of trichloro(octadecyl)silane (90%; Sigma-Aldrich). The mixture was stirred for 3 h at room temperature. The toluene of the mixture was evaporated at 368 K for 5 h to obtain hydrophobic SiO2 NPs. The hydrophobic SiO2 nanoparticles were stirred for 30 min and sonicated for 20 min after dissolving in 100 mL ethanol (Fisher Scientific, Hampton, NH, USA) to form a nanoparticle suspension.56 Fabrication of the SH/iMglue patch for tissue closure: For fabricating adhesive and the SH patches, iMglue was applied to both sides of the cotton pad (Cjolivenetworks, Youngsan, Seoul, Korea) and sprayed with 3 mL of hydrophobic SiO2 nanoparticle suspension on one side. The hydrophobic SiO2 NPs were sprayed at a distance of 10 cm under a pressure of 20 psi using a spray-gun (BD-130; Bluebird, Guangzhou, Guangdong-sheng, China). The coated surface was dried at room temperature for 5 min, and the unbound nanoparticles were thoroughly rinsed with DW. The upper side of the patch became superhydrophobic, and the bottom side of the patch was adhesive. A SH patch without the adhesive was fabricated as a comparative control. Peel adhesion test: The incised tissue adhesiveness by applying iMglue was measured via the peel adhesion test using porcine skin tissue (Stellen Medical, Saint Paul, MN, USA). The porcine skin tissues were sliced into 10 × 10 mm2 and incised approximately 8 mm in the middle. After the skin samples were completely swelled in PBS for 3 h, 10 mL of iMglue was evenly applied between incised skin tissue. For comparison, incised skin tissue without any treatment was prepared. After curing for 12 h at 37 °C, the peel adhesiveness of each sample 15



was measured by loading both ends of the tissue and pulling at a speed of 1.8 mm min-1 by a universal testing machine (Instron, Norwood, MA, USA) with a 2000 N load cell, as previously reported.24, 57 Antibacterial properties of the SH patches: The experiment to confirm the bacterial properties of the SH patches made with iMglue was performed in two ways. First, as it was developed as a patch for tissue closure, the SH surface of the patch should not penetrate contaminants such as bacteria. To determine how bacterial cells permeate into the SH patch and how they are distributed, GFP-expressing E. coli was employed for distinct visualization. E. coli BL 21 (DE3) cells were cultivated in Luria-Bertani (LB) medium (Affymetrix, Santa Clara, CA, USA) supplemented with 50 mg mL-1 ampicillin (Sigma-Aldrich). At the cell optical density of 0.6 at 600 nm (OD600), a final concentration of 0.1 M isopropyl--Dthiogalactopyranoside (IPTG; Sigma-Aldrich) was added to induce GFP expression. The bacterial adhesion and the growth of biofilms on SiO2-coated SH patches were examined by co-incubating the patch with GFP-expressing E. coli in culture media under a 60-rpm rotating agitator for 1 h. The bacterial adhesion and biofilms were measured under bright light and GFP detection light of optical microscopy (Leica, Wetzlar, Germany) and SEM. After measuring the overall size of the SH patch under bright light, we determined the contaminated area under GFP detection light. Through SEM, damaged SiO2 NPs attached to the SH patch were investigated after incubation due to shear stress and bioflim formation. Second, because blood repellency based on the SH surface is crucial in this field, 1 mL of blood microdroplets was dropped on the SH patch with or without iMglue. After dropping the blood, the patch was detached and visualized for the adsorbed blood inside.

16


Page 16 of 27

Page 17 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


ASSOCIATED CONTENT Supporting Information The following files are available free of charge. Supplementary figures (PDF)

AUTHOR INFORMATION Corresponding Author *E-mail: [email protected], [email protected] Author Contributions K.H., T.Y.P., K.Y and H.J.C. designed the study, analyzed the data, and wrote the paper; K.H. and T.Y.P. performed experiments. K.H., T.Y.P., K.Y and H.J.C. advised on the interpretation of the experiments. K.Y and H.J.C. directed the overall project. K.H. and T.Y.P. contributed equally to this work. All authors discussed the results and edited the manuscript. All authors have given approval to the final version of the manuscript.

ACKNOWLEDGMENT This work was supported by a Marine Biomaterials Research Center grant from the Marine Biotechnology Program of the Korea Institute of Marine Science & Technology Promotion funded by the Ministry of Oceans and Fisheries, Korea (to H.J. Cha) and a National Research Foundation grant (NRF-2016R1A4A1010735) to funded by the Ministry of Science and ICT, Korea (to K. Yong).

17



REFERENCES (1) Lu, Y.; Sathasivam, S.; Song, J.; Crick, C. R.; Carmalt, C. J.; Parkin, I. P. Robust SelfCleaning Surfaces that Function when Exposed to Either Air or Oil. Science 2015, 347, 11321135. (2) Baek, S.; Kim, W.; Jeon, S.; Yong, K. Developing a Non-optical Platform for Impact Dynamics Analysis on Nanostructured Superhydrophobic Surfaces Using a Quartz Crystal Microbalance. Sens. Actuator B-Chem. 2018, 262, 595-602. (3) Han, Z.; Feng, X.; Guo, Z.; Niu, S.; Ren, L. Flourishing Bioinspired Antifogging Materials with Superwettability: Progresses and Challenges. Adv. Mater. 2018, 30, e1704652. (4) Xue, Z.; Wang, S.; Lin, L.; Chen, L.; Liu, M.; Feng, L.; Jiang, L. A Novel Superhydrophilic and Underwater Superoleophobic Hydrogel-Coated Mesh for Oil/Water Separation. Adv. Mater. 2011, 23, 4270-4273. (5) Ge, J.; Zong, D.; Jin, Q.; Yu, J.; Ding, B. Biomimetic and Superwettable Nanofibrous Skins for Highly Efficient Separation of Oil-in-Water Emulsions. Adv. Funct. Mater. 2018, 28, 1705051. (6) Zhang, S.; Jiang, G.; Gao, S.; Jin, H.; Zhu, Y.; Zhang, F.; Jin, J. Cupric Phosphate Nanosheets-Wrapped Inorganic Membranes with Superhydrophilic and Outstanding Anticrude Oil-Fouling Property for Oil/Water Separation. ACS Nano 2018, 12, 795-803. (7) Wang, Z.; Liu, G.; Huang, S. In Situ Generated Janus Fabrics for the Rapid and Efficient Separation of Oil from Oil-in-Water Emulsions. Angew Chem Int Ed Engl 2016, 55, 1461014613. (8) Wang, G.; Wang, H.; Guo, Z. A Robust Transparent and Anti-fingerprint Superhydrophobic Film. Chem. Commun. (Camb) 2013, 49, 7310-7312. (9) Li, L.; Li, B.; Dong, J.; Zhang, J. Roles of Silanes and Silicones in Forming Superhydrophobic and Superoleophobic Materials. J. Mater. Chem. A 2016, 4, 13677-13725. (10) Baek, S.; Moon, H. S.; Kim, W.; Jeon, S.; Yong, K. Effect of Liquid Droplet Surface Tension on Impact Dynamics over Hierarchical Nanostructure Surfaces. Nanoscale 2018, 10, 17842-17851. (11) Epstein, A. K.; Wong, T. S.; Belisle, R. A.; Boggs, E. M.; Aizenberg, J. Liquid-infused Structured Surfaces with Exceptional Anti-biofouling Performance. Proc. Natl. Acad. Sci. U S A 2012, 109, 13182-13187. (12) Bruchmann, J.; Pini, I.; Gill, T. S.; Schwartz, T.; Levkin, P. A. Patterned SLIPS for the Formation of Arrays of Biofilm Microclusters with Defined Geometries. Adv. Healthc. Mater. 2017, 6, 1601082 18


Page 18 of 27

Page 19 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(13) Leslie, D. C.; Waterhouse, A.; Berthet, J. B.; Valentin, T. M.; Watters, A. L.; Jain, A.; Kim, P.; Hatton, B. D.; Nedder, A.; Donovan, K.; Super, E. H.; Howell, C.; Johnson, C. P.; Vu, T. L.; Bolgen, D. E.; Rifai, S.; Hansen, A. R.; Aizenberg, M.; Super, M.; Aizenberg, J.; Ingber, D. E. A Bioinspired Omniphobic Surface Coating on Medical Devices Prevents Thrombosis and Biofouling. Nat. Biotechnol. 2014, 32, 1134-1140. (14) Ellinas, K.; Kefallinou, D.; Stamatakis, K.; Gogolides, E.; Tserepi, A. Is There a Threshold in the Antibacterial Action of Superhydrophobic Surfaces? ACS Appl. Mater. Interfaces 2017, 9, 39781-39789. (15) Banerjee, I.; Pangule, R. C.; Kane, R. S. Antifouling Coatings: Recent Developments in the Design of Surfaces that Prevent Fouling by Proteins, Bacteria, and Marine Organisms. Adv. Mater. 2011, 23, 690-718. (16) Falde, E. J.; Yohe, S. T.; Colson, Y. L.; Grinstaff, M. W. Superhydrophobic Materials for Biomedical Applications. Biomaterials 2016, 104, 87-103. (17) Hwang, G. B.; Page, K.; Patir, A.; Nair, S. P.; Allan, E.; Parkin, I. P. The AntiBiofouling Properties of Superhydrophobic Surfaces are Short-lived. ACS Nano 2018, 12, 6050-6058. (18) Moradi, S.; Hadjesfandiari, N.; Toosi, S. F.; Kizhakkedathu, J. N.; Hatzikiriakos, S. G. Effect of Extreme Wettability on Platelet Adhesion on Metallic Implants: From Superhydrophilicity to Superhydrophobicity. ACS Appl. Mater. Interfaces 2016, 8, 1763117641. (19) Li, Y.; Chen, S.; Wu, M.; Sun, J. All Spraying Processes for the Fabrication of Robust, Self-healing, Superhydrophobic Coatings. Adv. Mater. 2014, 26, 3344-3348. (20) Lee, J.; Yong, K. Combining the Lotus Leaf Effect with Artificial Photosynthesis: Regeneration of Underwater Superhydrophobicity of Hierarchical ZnO/Si Surfaces by Solar Water Splitting. NPG Asia Mater. 2015, 7, e201. (21) Das, A.; Sengupta, S.; Deka, J.; Rather, A. M.; Raidongia, K.; Manna, U. Synthesis of Fish Scale and Lotus Leaf Mimicking, Stretchable and Durable Multilayers. J. Mater. Chem. A 2018, 6, 15993-16002. (22) Liu, M.; Li, J.; Hou, Y.; Guo, Z. Inorganic Adhesives for Robust Superwetting Surfaces. ACS Nano 2017, 11, 1113-1119. (23) Kotov, N. A.; Dekany, I.; Fendler, J. H. Layer-by-layer Self-assembly of Polyelectrolyte-semiconductor Nanoparticle Composite Films. J. Phys. Chem. A 1995, 99, 13065-13069.

19



(24) Lim, S.; Choi, Y. S.; Kang, D. G.; Song, Y. H.; Cha, H. J. The Adhesive Properties of Coacervated Recombinant Hybrid Mussel Adhesive Proteins. Biomaterials 2010, 31, 37153722. (25) Hwang, D. S.; Zeng, H.; Srivastava, A.; Krogstad, D. V.; Tirrell, M.; Israelachvili, J. N.; Waite, J. H. Viscosity and Interfacial Properties in a Mussel-inspired Adhesive Coacervate. Soft Matter 2010, 6, 3232-3236. (26) Kim, H. J.; Yang, B.; Park, T. Y.; Lim, S.; Cha, H. J. Complex Coacervates Based on Recombinant Mussel Adhesive Proteins: Their Characterization and Applications. Soft Matter 2017, 13, 7704-7716. (27) Choi, B.-H.; Choi, Y. S.; Kang, D. G.; Kim, B. J.; Song, Y. H.; Cha, H. J. Cell Behavior on Extracellular Matrix Mimic Materials based on Mussel Adhesive Protein Fused with Functional Peptides. Biomaterials 2010, 31, 8980-8988. (28) Shao, H.; Stewart, R. J. Biomimetic Underwater Adhesives with Environmentally Triggered Setting Mechanisms. Adv. Mater. 2010, 22, 729-733. (29) Winslow, B. D.; Shao, H.; Stewart, R. J.; Tresco, P. A. Biocompatibility of Adhesive Complex Coacervates Modeled after the Sandcastle Glue of Phragmatopoma Californica for Craniofacial Reconstruction. Biomaterials 2010, 31, 9373-9381. (30) Liu, Q.; Huang, B.; Huang, A. Polydopamine-based Superhydrophobic Membranes for Biofuel Recovery. J. Mater. Chem. A 2013, 1, 11970-11974. (31) Kang, S. M.; You, I.; Cho, W. K.; Shon, H. K.; Lee, T. G.; Choi, I. S.; Karp, J. M.; Lee, H. One‐step Modification of Superhydrophobic Surfaces by a Mussel‐inspired Polymer Coating. Angew. Chem. 2010, 49, 9401-9404. (32) Zhu, Q.; Pan, Q. Mussel-inspired Direct Immobilization of Nanoparticles and Application for Oil–water Separation. ACS Nano 2014, 8, 1402-1409. (33) Lee, D.; Rubner, M. F.; Cohen, R. E. All-Nanoparticle Thin-Film Coatings. Nano Letters 2006, 6, 2305-2312. (34) Hattori, H. Anti‐reflection Surface with Particle Coating Deposited by Electrostatic Attraction. Adv. Mater. 2001, 13, 51-54. (35) Knoblich, B.; Gerber, T. Aggregation in SiO2 Sols from Sodium Silicate Solutions. J. Non-Cryst. Solids 2001, 283, 109-113. (36) Barakat, M. A. Adsorption Behavior of Copper and Cyanide Ions at TiO2-solution Interface. J Colloid Interface Sci 2005, 291, 345-352. (37) Msaky, J.; Calvet, R. Adsorption Behavior of Copper and Zinc in Soils: Influence of pH on Adsorption Characteristics. Soil Science 1990, 150, 513-522. 20


Page 20 of 27

Page 21 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(38) Akcora, P.; Liu, H.; Kumar, S. K.; Moll, J.; Li, Y.; Benicewicz, B. C.; Schadler, L. S.; Acehan, D.; Panagiotopoulos, A. Z.; Pryamitsyn, V.; Ganesan, V.; Ilavsky, J.; Thiyagarajan, P.; Colby, R. H.; Douglas, J. F. Anisotropic Self-assembly of Spherical Polymer-grafted Nanoparticles. Nat. Mater. 2009, 8, 354-359. (39) Faucheux, N.; Schweiss, R.; Lutzow, K.; Werner, C.; Groth, T. Self-assembled Monolayers with Different Terminating Groups as Model Substrates for Cell Adhesion Studies. Biomaterials 2004, 25, 2721-2730. (40) Lee, H.; Dellatore, S. M.; Miller, W. M.; Messersmith, P. B. Mussel-inspired Surface Chemistry for Multifunctional Coatings. Science 2007, 318, 426-430. (41) Lee, B. P.; Messersmith, P. B.; Israelachvili, J. N.; Waite, J. H. Mussel-inspired Adhesives and Coatings. Annu. Rev. Mater. Res. 2011, 41, 99-132. (42) Metwalli, E.; Haines, D.; Becker, O.; Conzone, S.; Pantano, C. G. Surface Characterizations of Mono-, Di-, and Tri-aminosilane Treated Glass Substrates. J. Colloid Interface Sci. 2006, 298, 825-831. (43) Davie, E. W.; Fujikawa, K. Basic Mechanisms in Blood Coagulation. Annu. Rev. Biochem. 1975, 44, 799-829. (44) Nesbitt, W. S.; Westein, E.; Tovar-Lopez, F. J.; Tolouei, E.; Mitchell, A.; Fu, J.; Carberry, J.; Fouras, A.; Jackson, S. P. A Shear Gradient–dependent Platelet Aggregation Mechanism Drives Thrombus Formation. Nat. Med. 2009, 15, 665-673. (45) Hwang, D. S.; Gim, Y.; Yoo, H. J.; Cha, H. J. Practical Recombinant Hybrid Mussel Bioadhesive fp-151. Biomaterials 2007, 28, 3560-3568. (46) Jeon, E. Y.; Hwang, B. H.; Yang, Y. J.; Kim, B. J.; Choi, B.-H.; Jung, G. Y.; Cha, H. J. Rapidly Light-activated Surgical Protein Glue Inspired by Mussel Adhesion and Insect Structural Crosslinking. Biomaterials 2015, 67, 11-19. (47) Jeon, E. Y.; Choi, B.-H.; Jung, D.; Hwang, B. H.; Cha, H. J. Natural Healing-inspired Collagen-targeting Surgical Protein Glue for Accelerated Scarless Skin Regeneration. Biomaterials 2017, 134, 154-165. (48) Park, T. Y.; Jeon, E. Y.; Kim, H. J.; Choi, B.-H.; Cha, H. J. Prolonged Cell Persistence with Enhanced Multipotency and Rapid Angiogenesis of Hypoxia Pre-conditioned Stem Cells Encapsulated in Marine-inspired Adhesive and Immiscible Liquid Micro-droplets. Acta Biomater. 2019, on-line published, DOI: 10.1016/j.actbio.2019.01.007. (49) Hwang, D. S.; Waite, J. H.; Tirrell, M. Promotion of Osteoblast Proliferation on Complex Coacervation-based Hyaluronic Acid–recombinant Mussel Adhesive Protein Coatings on Titanium. Biomaterials 2010, 31, 1080-1084. 21



(50) Zhang, X.; Wang, L.; Levänen, E. Superhydrophobic Surfaces for the Reduction of Bacterial Adhesion. Rsc Advances 2013, 3, 12003-12020. (51) Choi, C.-H.; Kim, C.-J. Large Slip of Aqueous Liquid Flow over a Nanoengineered Superhydrophobic Surface. Phys. Rev. Lett. 2006, 96, 066001. (52) Chalfie, M.; Tu, Y.; Euskirchen, G.; Ward, W. W.; Prasher, D. C. Green Fluorescent Protein as a Marker for Gene Expression. Science 1994, 263, 802-805. (53) Ryan, G. B.; Grobéty, J.; Majno, G. Postoperative Peritoneal Adhesions: A Study of the Mechanisms. Am. J. Pathol. 1971, 65, 117-148. (54) Jokinen, V.; Kankuri, E.; Hoshian, S.; Franssila, S.; Ras, R. H. Superhydrophobic Blood‐Repellent Surfaces. Adv. Mater. 2018, 1705104. (55) Choi, B.-H.; Cheong, H.; Jo, Y. K.; Bahn, S. Y.; Seo, J. H.; Cha, H. J. Highly Purified Mussel Adhesive Protein to Secure Biosafety for In Vivo Applications. Microb Cell Fact. 2014, 13, 52. (56) Ogihara, H.; Xie, J.; Okagaki, J.; Saji, T. Simple Method for Preparing Superhydrophobic Paper: Spray-deposited Hydrophobic Silica Nanoparticle Coatings Exhibit High Water-repellency and Transparency. Langmuir 2012, 28, 4605-4608. (57) Kim, B. J.; Oh, D. X.; Kim, S.; Seo, J. H.; Hwang, D. S.; Masic, A.; Han, D. K.; Cha, H. J. Mussel-mimetic Protein-based Adhesive Hydrogel. Biomacromolecules 2014, 15, 15791585.

22


Page 22 of 27

Page 23 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 1. A comprehensive summary and biomedical multifunctionality of robust superhydrophobic surface with water-immiscible underwater adhesive.

23



Figure 2. Fabrication and characteristics of the SH SiO2(TiO2/SiO2)2 thin coating. a) Schematic illustration of the SH SiO2(TiO2/SiO2)2 thin coating synthesis procedure. b) Water contact angles of SH SiO2(TiO2/SiO2)2 thin coatings formed by different charge layers: AS, PDDA, and iMglue. c) Impact dynamics of water droplets on SH SiO2(TiO2/SiO2)2 thin coatings synthesized by different charge layers. All SH SiO2(TiO2/SiO2)2 thin coatings exhibit an anti-wetting state, implying low adhesion of water. d-g) SEM images of SH SiO2(TiO2/SiO2)2 thin coatings made using d) AS , e) PDDA, f-g) iMglue charge layers.

24


Page 24 of 27

Page 25 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 3. Mechanical robustness and application of an SH SiO2(TiO2/SiO2)2 thin coating employing iMglue. a) Picture of the tape abrasion test to appraise the mechanical robustness of the SH SiO2(TiO2/SiO2)2 thin coating. b) Water contact angles of SH SiO2(TiO2/SiO2)2 thin coatings depending on the tape abrasion cycle. c) The antithrombotic property of the catheter under different coating conditions: nontreatment as a negative control, treatment with iMglue only, and treatment with SH/iMglue. By flowing blood to the inside of the catheter at a constant rate (0.25 mL min-1), only the SH/iMglue catheter did not form blood coagulation.

25



Figure 4. The application of SH/iMglue patches for a tissue closure bandage. a) Schematic image of an SH patch fabricated by spraying hydrophobic SiO2 NPs on iMglue-coated patch (SH/iMglue patch). b) The normalized iMglue peel adhesiveness of the SH/iMglue patch applied to incised porcine skin. Bare incised porcine skin was used as a comparative control. c) The antibacterial effect of SH part of SH/iMglue patch by incubating in the culture broth of GFP-expressing E. coli. Depending on incubation time, the patches were observed in the bright field (left), GFP fluorescence (middle), and SEM (right). d) The blood-repellent effect of the SH/iMglue patch. While the SH/iMglue patch was repellent to blood adsorption, the bare patch adsorbed the blood when blood was dropped. 26


Page 26 of 27

Page 27 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


BRIEFS Robust superhydrophobic (SH) surface with biomedical multifunctionality are fabricated by combinational mimicking features of natural organisms: mussel, sandcastle worm, lotus leaf. The water-immiscible mussel adhesive protein (iMglue) enables any substrate to be easily formed SH surface with durability by electrical charge-controlled layer-by-layer growth of hydrophobic nanoparticles (NPs). This fabricated iMglue/NPs-based SH surface showed perfect multi-bifunctionality with excellent antibiofouling and tissue closure capabilities.

Table of Contents (TOC) graphic

27


Combinational Biomimicking of Lotus Leaf, Mussel, and Sandcastle

Recommend Documents