Surface Nanoengineering Research Articles

Biomimetic Surface Nanoengineering of Biodegradable Zn‐Based Orthopedic Implants for Enhanced Biocompatibility and Immunomodulation

AbstractZinc (Zn) is gaining increased recognition as a biodegradable metal in biomedical applications but clinical translation is limited due to its poor biocompatibility. This study addresses these issues through an innovative biomimetic strategy, introducing an efficient surface nanoengineering approach that creates nano‐geometric features and chemical compositions by modulating the exposure time to a biological medium – Dulbecco's Modified Eagle Medium(DMEM). These nanoengineered Zn implants exhibited tunable degradation rates. The nanostructures enhanced human osteoblast attachment, proliferation, and differentiation following direct contact, and improved macrophage function by promoting pseudopod formation and transitioning from a pro‐inflammatory M1 to a pro‐reparative M2 phenotype. In vivo studies show that the surface‐engineered implants effectively promoted tissue integration via M2 macrophage polarization, resulting in a favorable immunomodulatory environment, and increased collagen deposition. Proteomic analyses show that the tissues in the vicinity of the surface‐engineered Zn implants are enriched with proteins related to key wound healing biological mechanisms such as cell adhesion, cytoskeletal structural arrangement, and immune response. This study highlights the improved biocompatibility and anti‐inflammatory effects of surface‐engineered Zn, with important implications for the clinical translation of biodegradable Zn‐based orthopedic implants.

Cellulose Surface Nanoengineering for Visualizing Food Safety.

Food safety is vital to human health, necessitating the development of nondestructive, convenient, and highly sensitive methods for detecting harmful substances. This study integrates cellulose dissolution, aligned regeneration, in situ nanoparticle synthesis, and structural reconstitution to create flexible, transparent, customizable, and nanowrinkled cellulose/Ag nanoparticle membranes (NWCM-Ag). These three-dimensional nanowrinkled structures considerably improve the spatial-electromagnetic-coupling effect of metal nanoparticles on the membrane surface, providing a 2.3 × 108 enhancement factor for the surface-enhanced Raman scattering (SERS) effect for trace detection of pesticides in foods. Notably, the distribution of pesticides in the apple peel and pulp layers is visualized through Raman imaging, confirming that the pesticides penetrate the peel layer into the pulp layer (∼30 μm depth). Thus, the risk of pesticide ingestion from fruits cannot be avoided by simple washing other than peeling. This study provides a new idea for designing nanowrinkled structures and broadening cellulose utilization in food safety.

Optimizing the high-frequency magnetic properties of soft magnetic composites via surface nanoengineering

Owing to the presence of large residual internal stress during cold compaction, it is difficult to optimize the multiple high-frequency magnetic properties of amorphous soft magnetic composites (ASMCs) simultaneously. Here, a surface nanoengineering strategy was proposed to address the above dilemma by constructing a stress buffer layer composed of amorphous nano-particles, between amorphous powder and insulation coating. The amorphous FeSiBCCr@x wt.% FeB (x = 0.5, 1, 3) composite powders with core-shell structures were successfully prepared via an in-situ chemical reduction method. Especially, when the composite ratio of nano-particles is 1 wt.%, the comprehensive properties of the ASMC reach the best balance. Compared with the FeSiBCCr ASMC, the saturation magnetization of the modified ASMC enhances from 153 to 171 emu/g. Meanwhile, the core loss decreases by 28.25 %, while the effective permeability increases by 25 % and can stabilize to ∼20 MHz. Therefore, our work provides a strategy for achieving superior comprehensive soft magnetic properties of ASMCs via surface nanoengineering, which presents enormous application potential in high-frequency electric devices.

Polydopamine derived N-doped carbon nanocoatings on Cu oxide cones for enhancing boiling heat transfer performance

Constructing low thermal resistance, durable, and cost-effective thermal interface coatings on metal surface is urgent to solve the thermal management problem of advanced electronics. Herein, N-doped carbon (NC) nanocoatings on Cu oxide cones (NC600/CuO12h@Cu) were prepared by assembly and subsequent pyrolysis of polydopamine (PDA). The surface morphology and chemical components were tailored by varying the etching time in alkaline solution and pyrolysis temperature. SEM, XRD, XPS, TEM, Raman, AFM and contact angle measurements were performed to characterize the morphologies, compositions, and surface wettability. Systematic study disclosed that the boiling heat transfer performance of modified Cu substrate was significantly enhanced in the presence of NC coated Cu oxides. Heat transfer coefficient and critical heat flux of NC600/CuO12h@Cu increased by 197.6 % and 84.7 % in comparison with bare Cu surfaces when the etching time and annealing temperature were 12 h and 600 °C, respectively. The vertically-oriented in-plane heat dissipation direction of NC coating, the abundant nucleation sites and the superhydrophilicity synergistically enhanced the boiling performance. This PDA derived NC coating is assumed to be a promising surface nanoengineering strategy for optimizing the physicochemical properties and micro/nanostructures of metal surface, thus shows potential to improve the interfacial thermal performance for industrial thermal management.

Tune wastepaper to hydrophobic membranes through metal-ion-induced lignocellulose nanofibril crosslinking for oil-water separation

Herein, we proposed a metal-ion-induced surface nano-engineering technology for transforming hydrophilic waste newspaper (WNP) into a hydrophobic material suitable for oil-water separation, without using hydrophobic chemicals/materials. WNPs were swelled in a dilute ferric ion solution (i.e., 50 mM FeCl3) followed by oven-drying to induce the coordination between ferric ions and hydroxyls of lignocellulose nanofibrils of the paper. This resulted in the crosslinking of lignocellulose nanofibrils and converted the hydrophilic WNP to the hydrophobic membrane (HM). The HM exhibited remarkable oil sorption capacity for various oils, up to 3.4 times its weight, and demonstrated good recyclability after undergoing 10 cycles of absorption-desorption-drying. Additionally, HM demonstrated the ability to effectively separate both immiscible oil-water mixtures and surfactant-stabilized water-in-oil emulsions in continuous gravity-driven oil-water separation processes. With the modification method and advantages in oil-water separation, the as-prepared HM exhibits great potential for application in oil spill treatment and environmental remediation.

Surface nano-engineering of cellulosic textiles for superior biocidal performance and effective bacterial detection

In medical, healthcare, and packaging industries, antibacterial textiles are widely used. However, contamination of textiles with bacteria can result in exclusive cross-infection. To address this issue, we devised an engineering strategy for creating organic–inorganic hybrid layers on the surface of fiber materials by combining MXene quantum dots (MQDs) with highly efficient antimicrobial agents, endowing the textiles with dual functions of bacterial killing and monitoring. Surface-functionalized MQDs were anchored on the surface of cellulose nonwovens (CNWs) by hydrogen bonding (MQDs@CNWs), followed by immobilization of Ni2+ ions by metal affinity coordination (Ni@MQDs@CNWs). In the last step, the antimicrobial compounds with catechol moieties were coordinated with Ni2+ to produce the modified textile named as NCA@Ni@MQDs@CNWs. Fluorescence (FL) recovery experiments demonstrated that NCA@Ni@MQDs@CNWs had differential FL recovery ability after exposure to pathogens with different concentrations indicating its ability for bacteria monitoring. Moreover, NCA@Ni@MQDs@CNWs exhibited excellent bactericidal efficiencies of >99.99% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in a 30-min. This work presents a novel approach for design and fabrication of biocidal textiles with ability of sensing bacteria.

CMOS Image Sensor for Broad Spectral Range with >90% Quantum Efficiency.

Even though the recent progress made in complementary metal-oxide-semiconductor (CMOS) image sensors (CIS) has enabled numerous applications affecting our daily lives, the technology still relies on conventional methods such as antireflective coatings and ion-implanted back-surface field to reduce optical and electrical losses resulting in limited device performance. In this work, these methods are replaced with nanostructured surfaces and atomic layer deposited surface passivation. The results show that such surface nanoengineering applied to a commercial backside illuminated CIS significantly extends its spectral range and enhances its photosensitivity as demonstrated by >90% quantum efficiency in the 300-700nm wavelength range. The surface nanoengineering also reduces the dark current by a factor of three. While the photoresponse uniformity of the sensor is seen to be slightly better, possible scattering from the nanostructures can lead to increased optical crosstalk between the pixels. The results demonstrate the vast potential of surface nanoengineering in improving the performance of CIS for a wide range of applications.

Sequential SI-ATRP in μL-scale for surface nanoengineering: A new concept for designing polyelectrolyte nanolayers formed by complex architecture polymers

The article presents a step-by-step protocol, designed on the basis of principles of green chemistry, for the synthesis of polymer brushes with complex structure via surface-initiated atom transfer radical polymerization (SI-ATRP) approach. The selection of anionic (poly(acrylic acid), PAA) and cationic (poly(2-(dimethylamino)ethyl methacrylate, PDMAEMA) macromolecular chains enabled the formation of ampholytic polymer coating on silicon (Si) substrates. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) analyses confirmed changes in the structure of the synthesized nanolayer at each step of the surface modification. Finally, the synthesis protocol was rescaled presenting an extremely economically and environmentally beneficial procedure for the synthesis of Si wafers grafted with brushes composed of poly(2-hydroxyethyl methacrylate) (PHEMA) core and PDMAEMA and PAA as block polymer branches (Si-g-PHEMA-g-(PDMAEMA-b-PAA)) with application of microliter volumes of reactants.

Surface nanoengineering technology for the removal of sulfur compounds associated with negative attributes in wines

Volatile sulfur compounds (VSCs), such as hydrogen sulfide, methanethiol, and ethanethiol, are associated with ‘reductive’ aromas in wine and contribute to approximately 30% of all wine faults. These compounds can have a significant impact on wine aroma and perceived quality, and subsequently, consumer preference. In this communication, we report a method for the removal of VSC compounds based on nanoengineered surfaces that incorporate immobilized gold nanoparticles.

Nanotechnology-Assisted Biosensors for the Detection of Viral Nucleic Acids: An Overview.

The accurate and rapid diagnosis of viral diseases has garnered increasing attention in the field of biosensors. The development of highly sensitive, selective, and accessible biosensors is crucial for early disease detection and preventing mortality. However, developing biosensors optimized for viral disease diagnosis has several limitations, including the accurate detection of mutations. For decades, nanotechnology has been applied in numerous biological fields such as biosensors, bioelectronics, and regenerative medicine. Nanotechnology offers a promising strategy to address the current limitations of conventional viral nucleic acid-based biosensors. The implementation of nanotechnologies, such as functional nanomaterials, nanoplatform-fabrication techniques, and surface nanoengineering, to biosensors has not only improved the performance of biosensors but has also expanded the range of sensing targets. Therefore, a deep understanding of the combination of nanotechnologies and biosensors is required to prepare for sanitary emergencies such as the recent COVID-19 pandemic. In this review, we provide interdisciplinary information on nanotechnology-assisted biosensors. First, representative nanotechnologies for biosensors are discussed, after which this review summarizes various nanotechnology-assisted viral nucleic acid biosensors. Therefore, we expect that this review will provide a valuable basis for the development of novel viral nucleic acid biosensors.

Processing laser ablated plasmonic nanoparticle aerosols with nonthermal dielectric barrier discharge jets of argon and helium and plasma induced effects

Dielectric-barrier-discharge (DBD) plasma jets provide viable state-of-the-art nonthermal processes for a wide range of nanomaterials including particle transport and deposition. We report the interaction of argon and helium plasma jets with the particle aerosol, produced by ns laser ablation of a silver target and subsequently their transport for deposition on a distant substrate. The nanofeatures and functionality of the nanoparticles, entrained and deposited with the two plasma jets were compared using high-resolution electron microscopy, helium ion microscopy, scanning electron microscopy, ultraviolet–visible spectroscopy, and in terms of the SERS effect. The plasma jet facilitates the transport of the particle aerosol under the upshot of plasma ionic wind, caused by the high electric field in the plasma. Compared to the helium plasma jet, the argon plasma jet leads to a relatively large particle deposition and promotes the formation of aggregates. The helium plasma jet enabled the deposition of spatially well dispersed particles. In both cases, the deposited particle was crystalline and plasmonic active. The plasma-driven altered morphology, expedient particle transport, and formation of agglomerates or spatially well dispersed particles are explained in plasma-induced ionic-wind, and dusty plasma framework. The findings are novel and interesting from the perspective of plasma–surface deposition, surface nanoengineering, and nanomaterial processing for applications in sensing, catalysis, surgical tools, futuristic coating technology, and heat-sensible biological activities.

Strong absorption in ultra-wide band by surface nano engineering of metallic glass

Broadband light absorption is important for applications such as infrared detectors, solar energy collectors, and photothermal conversion. We propose a facile and common strategy to fabricate light absorbers with strong ultra-wideband absorption. Due to their excellent thermoplastic forming ability, metallic glasses could be patterned into finely arranged nanowire arrays, which show extremely low reflectivity (∼0.6%) in the visible and near-infrared regimes, and a low reflectivity (∼15%) in the mid-infrared regime as caused by multiscale nano spacing, multiple reflections, and plasmonic behavior. The strong absorption at surfaces with nanowires provides excellent photothermal conversion properties. The photothermal properties show that a surface with nanowires can be rapidly heated up to ∼160 °C at a rate of 28.75 °C/s, which is 30 times higher than smooth surfaces. Meanwhile, a surface with nanowires shows a high photothermal conversion efficiency (ηPT = 56.36%). The fabricated metallic glass absorbers exhibit adaptability as they can be easily formed into various complex shapes and meet the requirements under harsh conditions. The outcomes of our research open the door to manufacturing high-performance absorbers for applications in photothermal electric power generation, desalination, and photodetectors.

Graphene coated sand for smart cement composites

• The GO on the GO-coated sand anneals and then microwaves to graphene-coated sand. • Self-sensing cement composites enable by nano-engineers cement-aggregate interfaces. • The conductive path in mortar mainly consists of G@sand with ITZ located in between. • M-G@FAg mortar demonstrates electrical resistivity of 960 Ω·cm and an FCR of ∼ 18%. Unlike conventional approaches of direct addition of carbon-based conductive fillers into cement matrix in developing smart sensing composites, this study proposes a targeted and therefore more efficient approach through nano-surface engineering of the sand. Specifically, a simple method that enables uniform adsorption of graphene oxide onto the surface of the sand particles, followed by simple annealing and microwave treatment to prepare graphene-coated sand (conductive aggregates). Scanning electron microscopy indicates that about 62.2% of the sand surface area is successfully coated by graphene, with an average thickness of approximately 8.8 nm. The mortar incorporating conductive aggregates demonstrates outstanding electrical conductivity (resistivity of 960 Ω·cm) and a high fractional change in resistivity of ∼ 18% under cyclic compressive loading, which outperforms previously reported results obtained by direct addition of graphene or carbon nanotubes at equivalent concentrations. The use of conductive aggregates in mortars also results in other minor benefits such as a slight enhancement in flowability and reduction in water sorptivity. All of these were achieved without substantial reduction in 28-d compressive strength. These findings demonstrate a great potential of aggregate surface nano-engineering for developing smart cement-based composites for practical sensing applications.

Four-Component Ugi Reaction for Optical Chirality Sensing and Surface Nanoengineering of Chiral Self-Assemblies.

Using green chemistry to control chirality at hierarchical levels as well as chiroptical activities endows with new opportunities to the development of multiple functions. Here, the four-component Ugi reaction is introduced for the general and precise optical chirality sensing of amines as well as the surface nanoengineering of chiral soft self-assemblies. To overcome the relatively weak Cotton effects, direct synthesis of a folded peptide structure on a rotatable ferrocene core with axial chirality was accomplished from chiral amine, 1,1'-ferrocenyl dicarboxylic acid, formaldehyde and isocyanide. Enhanced Cotton effects benefiting from the folded structure allow for the precise and quantitative sensing of natural and synthetic chiral amines covering alkyl, aromatic amines and amino acid derivatives. In addition, aqueous reaction enables the modification of amine-bearing dye to microfibers self-assembled from π-conjugated amino acids. Surface dye-modification via Ugi reaction barely changes the pristine morphology, showing non-invasive properties in contrast to dye staining, which is applicable in soft nano/microarchitectures from self-assembly. This work which combines the four-component Ugi reaction to enable precise ee% detection and surface nanoengineering of soft chiral assemblies sheds light on the advanced application of green chemistry to chirality science.

The potential of surface nano-engineering in characteristics of cobalt-based nanoparticles and biointerface interaction with prokaryotic and human cells

Cobalt-based nanoparticles (CBNPs) have recently received great attention in biomedical studies; however, the possible biotoxicity of these nanoparticles (NPs) has remained a foremost concern that should be addressed. As surface functionalization is one of the helpful proposed solutions, we aimed to apply Lipoamino acids (LAAs) as a coating agent to improve biocompatibility. To this purpose, cobalt oxide, cobalt ferrite, and iron oxide nanoparticles (IONs) were synthesized with and without 2-amino-hexadecanoic acid coating to assess the impacts of LAA coating on characteristics and biocompatibility of CBNPs in human cells and compare with IONs, a widely used magnetic NPs in biomedicine. Antibacterial activities of NPs were evaluated against four Gram-negative and Gram-positive bacteria species to assess their biointerface interaction with prokaryotic cells. In addition, the antibacterial activities of synthesized NPs were compared to silver NPs, one of the widely used antimicrobial NPs and standard antibiotics (ampicillin). The structural characteristics properties of NPs were analyzed using TEM, FE-SEM, EDS, FTIR, XRD, and VSM. These NPs exhibited sphere-like to polygon-like morphology with desirable mean size. CBNPs displayed dose-dependent cytotoxicity and antimicrobial activities against human cell lines and all tested microbial species, as well as more cytotoxicity and bacterial inhibition compared to IONs. Besides, the results revealed that LAA coating could significantly improve the biocompatibility and antibacterial activity of NPs while impacting magnetic properties. To sum up, it seems that surface functionalization could provide more potent tools for bioapplications with improving biocompatibility and bacterial inhibition of CBNPs, though; further studies are needed in this regard.

Opportunities in Nano-Engineered Surface Designs for Enhanced Condensation Heat and Mass Transfer

AbstractRecent advancements in surface nano-engineering have spurred intense interests in their implementation for enhancing condensation heat transfer. When appropriately designed, nano-engineered surfaces not only lead to highly efficient transport mechanisms not achievable with conventional dropwise condensation (DWC), they also demonstrate the possibility of augmenting condensation of low surface tension fluids widely used in industry. These advantages are further enhanced by the development of highly scalable nanofabrication methods, which enable the potential transition from laboratory-scale prototypes to real-world industrial applications. In this review, we discuss the progress, opportunities, and challenges of enhancing condensation heat and mass transfer with nano-engineered surfaces. This article provides an overview of the recent developments in micro/nanoscale coating and structure fabrication techniques and performs a thorough comparison of their condensation performance, elucidating the complex interfacial transport mechanism involved. Surface structuring methods that are durable, scalable, and low-cost are essential attributes for large-scale industrial implementation. Here, the methods used to improve surface durability and demonstrations of nanostructure-enhanced meter-scale condensers are presented. Limitations are discussed and the potential techniques to overcome these challenges are summarized. Given the recent development of metal additive manufacturing (AM) technology and its growing relevance in manufacturing processes, we end this review by providing our perspectives on the opportunities in enabling surface nanostructuring of metal additive manufactured materials and the potential of nanometric–millimetric codesign optimization for the development of next-generation additively manufactured condensers.

Enhanced deposition of Fe(III)-tannic acid complex nanofilm by Fe(III)-embedded dextran nanocoating

Nanofilm deposition with Fe(III)-tannic acid (TA) complex serves as a surface nanoengineering technique for a wide variety of substrate materials. However, it has been still elusive to tune the fundamental nanofilm properties, such as thickness and roughness, for a single Fe(III)-TA layer. Here we demonstrate Fe(III)-embedded dextran nanocoating serving as a boosting layer for enhanced deposition of Fe(III)-TA complex nanofilm with higher roughness. The formation of Fe(III)-embedded dextran layer with 0.37 mM FeCl3·6H2O shows maximum three times deposition enhancement of Fe(III)-TA layer in film thickness (ca. 9 nm), compared with the conventional deposition. pH stability tests show that the multilayer structures formed with Fe(III)-TA layers and Fe(III)-embedded dextran layers are highly stable at pH 7.4 but gradually and rapidly degrade at pH 10 and pH 2, respectively. Further surface characterizations disclose that solution pH, correlated with the concentration of Fe(III) source (FeCl3·6H2O), is the major factor governing the deposition enhancement effect: more than 1.85 mM FeCl3·6H2O makes significantly acidic chemical environments hampering the further deposition of Fe(III)-TA nanofilms. The experimental findings herein provide clues for deeper understanding of metal-polyphenol complex nanofilm deposition as well as contribute to the future development of biocompatible nanocoating utilizing promising combinations of polysaccharides and polyphenols.

Controlled Pulmonary Delivery of Carrier-Free Budesonide Dry Powder by Atomic Layer Deposition.

Ideal controlled pulmonary drug delivery systems provide sustained release by retarding lung clearance mechanisms and efficient lung deposition to maintain therapeutic concentrations over prolonged time. Here, we use atomic layer deposition (ALD) to simultaneously tailor the release and aerosolization properties of inhaled drug particles without the need for lactose carrier. In particular, we deposit uniform nanoscale oxide ceramic films, such as Al2O3, TiO2, and SiO2, on micronized budesonide particles, a common active pharmaceutical ingredient for the treatment of respiratory diseases. In vitro dissolution and ex vivo isolated perfused rat lung tests demonstrate dramatically slowed release with increasing nanofilm thickness, regardless of the nature of the material. Ex situ transmission electron microscopy at various stages during dissolution unravels mostly intact nanofilms, suggesting that the release mechanism mainly involves the transport of dissolution media through the ALD films. Furthermore, in vitro aerosolization testing by fast screening impactor shows a ∼2-fold increase in fine particle fraction (FPF) for each ALD-coated budesonide formulation after 10 ALD process cycles, also applying very low patient inspiratory pressures. The higher FPFs after the ALD process are attributed to the reduction in the interparticle force arising from the ceramic surfaces, as evidenced by atomic force microscopy measurements. Finally, cell viability, cytokine release, and tissue morphology analyses verify a safe and efficacious use of ALD-coated budesonide particles at the cellular level. Therefore, surface nanoengineering by ALD is highly promising in providing the next generation of inhaled formulations with tailored characteristics of drug release and lung deposition, thereby enhancing controlled pulmonary delivery opportunities.

Drug powders with tunable wettability by atomic and molecular layer deposition: From highly hydrophilic to superhydrophobic

The wettability of pharmaceuticals is a key physical property which influences their dissolution rate, dispersibility, flowability and solid-state stability. Here, we provide a platform of surface nanoengineering methods capable of tuning the wettability of drug powders from high hydrophilicity to superhydrophobicity with drug loadings up to 95–99%. Specifically, we functionalize gram-scale micronized budesonide, a commercial active pharmaceutical ingredient for respiratory diseases, in a vibrated fluidized bed reactor with inorganic Al2O3, TiO2 and SiO2 by atomic layer deposition (ALD), organic poly(ethylene terephthalate) (PET) by molecular layer deposition (MLD) and inorganic/organic titanicone by hybrid ALD/MLD. Transmission electron microscopy shows the formation of smooth and uniform films for each deposition process without significantly affecting the surface morphology of the budesonide particles. Crucially, the deposition processes do not alter the solid-state structure and cytocompatibility of budesonide. The ceramic ALD films are able to convert the originally hydrophobic budesonide into highly hydrophilic powders with water contact angles (WCAs) of ~10° within a few seconds. The purely organic PET films grown via MLD deliver superhydrophobic powders with a WCA of 145–150°. In contrast, the titanicone hybrid ALD/MLD films lead to mild hydrophilicity with WCAs ranging from ~80° to ~60°. Modifying the wetting properties of inhaled drug powders such as budesonide is relevant to improve bioavailability, enhance the dispersion of formulations in suspension-based inhalers or prevent moisture interactions in dry powder inhalers. Moreover, by tuning the surface chemical composition at the atomic or molecular level, particle ALD, MLD and hybrid ALD/MLD enable control over powder wettability for several pharmaceutical dosage forms with applications in oral, orally inhaled and parenteral delivery.

Highly efficient and robust catalysts for the hydrogen evolution reaction by surface nano engineering of metallic glass

The synthesized hybrid electrocatalyst has excellent efficiency and stability for the HER.