Self-polymerization Of Dopamine Research Articles

Polydopamine Coating of Graphitic Carbon Nitride, g-C3N4, Improves Biomedical Application

Graphitic carbon nitride (g-C3N4) is an intriguing nanomaterial that exhibits photoconductive fluorescence properties under UV–visible light. Dopamine (DA) coating of g-C3N4 prepared from melamine was accomplished via self-polymerization of DA as polydopamine (PDA). The g-C3N4 was coated with PDA 1, 3, and 5 times repeatedly as (PDA@g-C3N4) in tris buffer at pH 8.5. As the number of PDA coatings was increased on g-C3N4, the peak intensity at 1512 cm−1 for N–H bending increased. In addition, the increased weight loss values of PDA@g-C3N4 structures at 600 °C from TGA thermograms confirmed that the coating was accomplished. The band gap of g-C3N4, 2.72 eV, was reduced to 0.87 eV after five coatings with PDA. A pristine g-C3N4 was found to have an isoelectric point (IEP) of 4.0, whereas the isoelectric points of 1PDA@g-C3N4 and 3PDA@g-C3N4 are close to each other at 3.94 and 3.91, respectively. On the other hand, the IEP of 5PDA@g-C3N4 was determined at pH 5.75 assuming complete coating with g-C3N4. The biocompatibility of g-C3N4 and PDA@g-C3N4 against L929 fibroblast cell lines revealed that all PDA@g-C3N4 coatings were found to be biocompatible up to a 1000 mg/mL concentration, establishing that PDA coatings did not adversely affect the biocompatibility of the composite materials. In addition, PDA@g-C3N4 was screened for antioxidant potential via total phenol content (TPC) and total flavonoid content assays and it was found that PDA@g-C3N4 has recognizable TPC values and increased linearly with an increased number of PDA coatings. Furthermore, blood compatibility of pristine g-C3N4 is enhanced considerably upon PDA coating, affirmed by hemolysis and the blood clotting index%. Additionally, α-glucosidase inhibitory properties of PDA@g-C3N4 structures revealed that 67.6 + 9.8% of this enzyme was evenly inhibited by 3PDA@g-C3N4 structure.

Mussel-Inspired Polymer-Based Coating Technology for Antifouling and Antibacterial Properties.

Zwitterionic coatings provide a promising antifouling strategy against biofouling adhesion. Quaternary ammonium cationic polymers can effectively kill bacteria on the surface, owing to their positive charges. This strategy can avoid the release of toxic biocides, which is highly desirable for constructing coatings for biomedical devices. The present work aims to develop a facile method by covalently grafting zwitterionic and cationic copolymers containing aldehydes to the remaining amine groups of self-polymerized dopamine. Reversible addition-fragmentation chain transfer polymerization was used to copolymerize either zwitterionic 2-methacryloyloxyethyl phosphorylcholine monomer (MPC) or cationic 2-(methacryloyloxy)ethyl trimethylammonium monomer (META) with 4-formyl phenyl methacrylate monomer (FPMA), and the formed copolymers poly(MPC-st-FPMA) and poly(META-st-FPMA) are denoted as MPF and MTF, respectively. MPF and MTF copolymers were then covalently grafted onto the amino groups of polydopamine-coated surfaces. PDA/MPF/MTF-coated surfaces exhibited antibacterial and antifouling properties against S. aureus, E. coli, and bovine serum albumin protein. In addition, they showed excellent viability of normal human lung fibroblast cells MRC-5. We expect the facile surface modification strategy discussed here to be applicable to medical device manufacturing.

A new three-dimensional (3D) molecularly imprinted polymer fluoroprobe based on green-red dual-emission signals of carbon quantum dots and self-polymerization of dopamine (CDs@PDA-MIPs) for sensitive detection of nifedipine.

Nifedipine (NIF), as one of the dihydropyridine calcium channel blockers, is widely used in the treatment of hypertension. However, misuse or ingestion of NIF can result in serious health issues such as myocardial infarction, arrhythmia, stroke, and even death. It is essential to design a reliable and sensitive detection method to monitor NIF. In this work, an innovative molecularly imprinted polymer dual-emission fluorescent sensor (CDs@PDA-MIPs) strategy was successfully designed for sensitive detection of NIF. The fluorescent intensity of the probe decreased with increasing NIF concentration, showing a satisfactory linear relationship within the range 1.0 × 10-6M ~ 5.0 × 10-3M. The LOD of NIF was 9.38 × 10-7M (S/N = 3) in fluorescence detection. Theapplication of the CDs@PDA-MIPs in actual samples such as urine and Qiangli Dingxuan tablets has been verified, with recovery ranging from 97.8 to 102.8% for NIF. Therefore, the fluorescent probe demonstrates great potential as a sensing system for detecting NIF.

Insight into the tribological properties of cylinder liner-piston ring under the nano BNNs/Cu composite additive lubrication

To improve the tribological properties of the cylinder liner-piston ring, a two-dimensional hexagonal boron nitride/copper composite lubricant additive was prepared and characterized in detail. The tribological properties and lubrication mechanism of nano hexagonal boron nitride composites with different concentrations were studied through the reciprocating friction test on the Rtec friction and wear tester. The results show that copper is successfully reduced and attached to the surface of h-BN nanosheets through the self-polymerization of dopamine, and the spherical structure promotes the interlayer slip of the nanosheets during the reciprocating friction process. The appropriate concentration of nano composite additives has excellent anti-friction and anti-wear properties. At 1 Hz and 100 N, the friction coefficient and wear quality of the nano composite additive with a concentration of 2 wt% were reduced by 29.07% and 76%, respectively. The surface Sq value and Sz value of the cylinder liner sample decreased by 68.06% and 74.47%. At the same time, under the condition of high speed and heavy load, the average wear depth of the cylinder liner sample is reduced by 61.3%. The nano composite material additive forms an excellent friction protective film on the wear surface of the cylinder liner, which can better enter the wear surface of the cylinder liner and produce a filling and repairing effect. The research results provide a method for the use of nano hexagonal boron nitride composite additives to inhibit the wear of cylinder liner-piston ring of Marine diesel engines.

Antibacterial MXene composite with excellent U/V selectivity for uranium extraction

Uranium, as a radioactive element, is the source of utilizable energy for mankind in the future. Large quantities of uranium resources are contained in seawater, so uranium extraction from seawater is undoubtedly the most feasible method. However, the presence of competitive ions such as vanadium hinders the efficient extraction of uranium, which is currently a challenge that needs to be solved. Here, silane coupling agent (KH550) was grafted onto two-dimensional metal carbide (MXene). Subsequently, salicylaldoxime (SA) was deposited onto MXene particles using self-polymerization of dopamine (DA) to prepare PDA/SA deposited MXene composite grafted with KH550 (PDA/SA/MXene-KH550). The adsorbent exhibited excellent selectivity for uranium ions with a uranium/vanadium selectivity ratio of 4.8. In antibacterial experiments, the PDA/SA/MXene-KH550 composite showed excellent antibacterial performance against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), demonstrating the ability to adapt to complex marine microbial contamination. In addition, the maximum experimental uranium adsorption capacity of the composite was 332.3 mg/g, following the pseudo-second-order kinetic model and the Langmuir isotherm model. After five adsorption-desorption cycles, the elution efficiency of PDA/SA/MXene-KH550 for uranium can still reach 74.7 %, which demonstrated that the adsorbent had superior stability and regeneration ability, providing the possibility for actual enrichment of uranium.

Preparation of dopamine/L-cysteine modified PVDF composite membrane and its application in the removal of mercury ions from water

Polyvinylidene fluoride (PVDF), embodying a stabilization under thermal environment and capability to resist chemical corrosion, is widely used as a membrane-forming material. However, its inherent hydrophobicity and lack of active functional groups in the structure limit its suitability for adsorption applications. In this study, PVDF-based membranes were first prepared by the non-solvent phase inversion method, and then, polydopamine (PDA) was coated on these membranes by the oxidative self-polymerization of dopamine (DA). Then, L-cysteine (LCys) was grafted by self-assembly to obtain a highly hydrophilic PVDF composite (PVDF@PDA-LCys) membrane with excellent ability for Hg(II) ion capture. The membrane has the following characteristics: excellent hydrophilicity, with a water contact angle (WCA) that drops to 0° within 3s, which is far superior to the 89.22° WCA of the PVDF-based membrane. Given an 10mg·L-1 initial concentration of Hg(II), adsorption experiences 120min, the removal efficiency reaches 95.14%. The fitted maximum adsorption capacity is 97.98mg·g-1. Additionally, the composite membrane exhibits good acid resistance. When the solution pH is as low as 1.5, the Hg(II) ion removal efficiency is still close to 70%. The performance of the composite membrane remains stable after repeated use. This study demonstrates an environmentally friendly and practical method for preparing PVDF-based composite membranes with potential applications in wastewater treatment.

Fabrication of high-flux PTFE hollow fiber membranes through nonionic surfactant infiltration coupled with mussel-inspired chemistry coating

Polytetrafluoroethylene (PTFE) hollow fiber membrane holds tremendous potential for the treatment of complex wastewater due to its outstanding chemical and thermal stability. However, its treatment efficiency is often hindered by the low water permeate flux arising from the inherent hydrophobicity of PTFE. Here, we present a gentle and convenient hydrophilic modification method that involves immersion in a nonionic surfactant aqueous solution, followed by dopamine self-polymerization. The nonionic surfactant facilitated the penetration of the dopamine solution into the membrane, where dopamine self-polymerized to form a hydrophilic layer on the surface and inner pores of the membrane. The hydrophilicity-modified PTFE hollow fiber membranes demonstrated an impressive increase in water permeate flux, reaching 10231.4 L m−2 h−1, nearly ten times that of the original membrane. Even after prolonged exposure to a strong acid solution (pH = 1) or an oxidant solution (1000 mg L−1 NaClO) for two weeks, this membrane still maintained its favorable water permeability. Furthermore, the modified PTFE membranes also exhibited remarkable resistance to fouling by humic acid. These results showcased a straightforward method for designing a hydrophilic layer on PTFE hollow fiber membranes, underscoring their significant potential for real wastewater treatment applications.

The interface modification with polyethyleneimine enhances both ionic conductivity and interfacial compatibility of composite solid electrolyte

The composite solid electrolyte (CSE), polyethylene oxide (PEO)-Li6.4La3Zr1.4Ta0.6O12 (LLZTO), is deemed a promising candidate for all-solid-state batteries. Nevertheless, due to the poor interfacial compatibility between LLZTO nanoparticles and PEO, achieving a homogeneous dispersion of LLZTO nanoparticles within PEO is not readily attainable. The aggregation of LLZTO within PEO leads to a decline in the ionic conductivity of the CSE and poor interface stability with the electrode, ultimately resulting in deteriorated battery cyclic performance. In this work, the interface between LLZTO and PEO is designed and comprehensively investigated. Initially, dopamine self-polymerization is employed to form a uniform coating layer on the surface of LLZTO nanoparticles. Subsequently, by utilizing the amino groups present in polyethyleneimine (PEI), which can react with the phenolic hydroxyl groups of dopamine and the ether linkages in PEO, PEI serves as a bridging agent, enhancing the interfacial compatibility between LLZTO and PEO. Here it is shown that, the ionic conductivity of the LLZTO-PEO CSE containing 40 wt% modified LLZTO increases from 6.14✕10−5 S cm−1 to 1.89✕10−4 S cm−1. Furthermore, this CSE exhibits improved thermal stability, an enlarged electrochemical window of 4.8 V, a lithium-ion transference number of 0.45, and excellent interface stability with the lithium anode. The assembled LiFePO4 | 40 wt% LLZTO@PDA@PEI-PEO CSE | Li all-solid-state battery demonstrates an initial discharge specific capacity of 151.8 mA h g−1 at 0.2 C, with a capacity retention of 85.8% after 200 cycles. This work provides a novel strategy for interface-modified polymer- inorganic composite solid electrolytes, which will advance the development of high-energy-density all-solid-state lithium batteries.

Injectable microspheres adhering to the cartilage matrix promote rapid reconstruction of partial-thickness cartilage defects

An effective treatment for the irregular partial-thickness cartilage defect in the early stages of osteoarthritis (OA) is lacking. Cartilage tissue engineering is effective for treating full-thickness cartilage defects with limited area. In this study, we designed an injectable multifunctional poly(lactic-co-glycolic acid) (PLGA) microsphere to repair partial-thickness cartilage defects. The microsphere was grafted with an E7 peptide after loading the microsphere with kartogenin (KGN) and modifying the outer layer through dopamine self-polymerization. The microsphere could adhere to the cartilage defect, recruit synovial mesenchymal stem cells (SMSCs) in situ, and stimulate their differentiation into chondrocytes after injection into the articular cavity. Through in vivo and in vitro experiments, we demonstrated the ability of multifunctional microspheres to adhere to cartilage matrix, recruit SMSCs, and promote their differentiation into cartilage. Following treatment, the cartilage surface of the model group with partial-thickness cartilage defect showed smooth recovery, and the glycosaminoglycan content remained normal; the untreated control group showed significant progression of OA. The microsphere, a framework for cartilage tissue engineering, promoted the expression of SMSCs involved in cartilage repair while adapting to cell migration and growth. Thus, for treating partial-thickness cartilage defects in OA, this innovative carrier system based on stem cell therapy can potentially improve therapeutic outcomes. Statement of significanceMesenchymal stem cells (MSCs) therapy is effective in the repair of cartilage injury. However, because of the particularity of partial-thickness cartilage injury, it is difficult to recruit enough seed cells in situ, and there is a lack of suitable scaffolds for cell migration and growth. Here, we developed polydopamine surface-modified PLGA microspheres (PMS) containing KGN and E7 peptides. The adhesion ability of the microspheres is facilitated by the polydopamine layer wrapped in them; thus, the microspheres can adhere to the injured cartilage and recruit MSCs, thereby promoting their differentiation into chondrocytes and accomplishing cartilage repair. The multifunctional microspheres can be used as a safe and potential method to treat partial-thickness cartilage defects in OA.

Abstract 5736: Sonochemical preparation of SP94 peptide-decorated pH-responsive biodegradable biopolyester nanoparticles for targeted therapy in hepatocellular carcinoma

Abstract Stimulation in response to nanoparticles responding to endogenous stimuli in the tumor microenvironment has been extensively studied for the release of chemotherapeutic drug. Therefore, we aimed to develop a biocompatible delivery of taxol (TAX) delivery vector system for the treatment of hepatocellular carcinoma (HCC). A basic backbone, TAX loaded poly (3-hydroxybutyrate-co-3-hydroxyvalerate) PHBV nanoparticle (PHBV-TAX-NPs), were designed and prepared via sonochemical method. The pH-responsive shell of PHBV-TAX-NPs was formed by oxidative self-polymerization of dopamine (PDA) in an alkaline environment. The HCC-targeted peptide SP94 binds to PDA-coated nanoparticles (NPs) through the Michael reaction. Moreover, the nanoparticle surface-grafted SP94 peptide serve as a specific ligand for targeting HCC. The chemical structures and properties of these nanoparticles were characterized by transmission electron microscope, dynamic light scattering-autosizer, differential scanning calorimetry, fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetry. As expected, excellent targeting of these SP94-PDA-PHBV-TAX-NPs was demonstrated by cellular uptake and cytotoxicity experiments in HCC cells. Compared with that of free TAX, the SP94-PDA-PHBV-TAX-NPs showed more superior antitumor efficacy in the xenograft mouse model. Notably, the SP94-PDA-PHBV-TAX-NPs were except for their potent anticancer activity, it was less toxic in vitro and in vivo compared to TAX in mice. These studies suggest the potential beneficial use of SP94-PDA-PHBV-TAX-NPs in future HCC-targeted therapy with drug-loaded nanocarriers. Citation Format: Mingfang Wu, Qi Wang, Zhengran Gong, Zixuan Liu, Haodong Zheng, Xinjie Chen, Chen Zhong. Sonochemical preparation of SP94 peptide-decorated pH-responsive biodegradable biopolyester nanoparticles for targeted therapy in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5736.

Recyclable and selective PVDF-based multifunctional molecular imprinted membranes for the removal of Bisphenol A

Bisphenol A (BPA) has been widely detected in environmental and human products and has significant health and environmental impacts. Consequently, an innovative molecularly imprinted membrane was fabricated for the selective adsorption of BPA within water environment. Tannic acid (TA), abundant in plants, was employed to effectuate the reduction of AgNO3 in an environmentally friendly, and gentle manner, imbuing the membrane with antibacterial properties. A functional hydrophilic layer was created utilizing TA and polyimide (PEI), and mild and efficient imprinting was accomplished through dopamine (DA) self-polymerization. Compared with the blank membrane, the contact angle of the molecularly imprinted membranes (PVDF@Ag@P@MIMs) was reduced to 67.62°, and the optimal adsorption capacity was 33.41 mg g−1. The imprinting factor of the PVDF@Ag@P@MIMs membrane was 2.90, indicating that the membrane could effectively separate BPA. After 6 cycles of utilization, the adsorption loss was only 4.55 %. In addition, the synthesis of PVDF@Ag@P@MIMs is simple and free of pollutants. The experimental results and green synthesis process of the molecularly imprinted membranes indicate that these materials have potential applications in environmental protection, selective separation, chemical industry, and other fields.

Dopamine Polymerization-Mediated Surface Functionalization toward Advanced Bacterial Therapeutics.

ConspectusBacteria-based therapy has spotlighted an unprecedented potential in treating a range of diseases, given that bacteria can be used as both drug vehicles and therapeutic agents. However, the use of bacteria for disease treatment often suffers from unsatisfactory outcomes, due largely to their suboptimal bioavailability, dose-dependent toxicity, and low targeting colonization. In the past few years, substantial efforts have been devoted to tackling these difficulties, among which methods capable of integrating bacteria with multiple functions have been extensively pursued. Different from conventional genetic engineering and modern synthetic bioengineering, surface modification of bacteria has emerged as a simple yet flexible strategy to introduce different functional motifs. Polydopamine, which can be easily formed via in situ dopamine oxidation and self-polymerization, is an appealing biomimetic polymer that has been widely applied for interfacial modification and functionalization. By virtue of its catechol groups, polydopamine can be efficiently codeposited with a multitude of functional elements on diverse surfaces.In this Account, we summarize the recent advances from our group with a focus on the interfacial polymerization-mediated functionalization of bacteria for advanced microbial therapy. First, we present the optimized strategy for bacterial surface modification under cytocompatible conditions by in situ dopamine polymerization. Taking advantage of the hydrogen bonding, π-π stacking, Michael addition, and Schiff base reaction with polydopamine, diverse functional small molecules and macromolecules are facilely codeposited onto the bacterial surface. Namely, monomodal, dual-modal, and multimodal surface modification of bacteria can be achieved by dopamine self-deposition, codeposition with a unitary composition, and codeposition with a set of multiple components, respectively. Second, we outline the regulation of bacterial functions by surface modification. The formed polydopamine surface endows bacteria with the ability to resist in vivo insults, such as gastrointestinal tract stressors and immune clearance, resulting in greatly improved bioavailability. Integration with specific ligands or therapeutic components enables the modified bacteria to increase targeting accumulation and colonization at lesion sites or play synergistic effects in disease treatment. Bacteria codeposited with different bioactive moieties, such as protein antigens, antibodies, and immunoadjuvants, are even able to actively interact with the host, particularly to elicit immune responses by either suppressing immune overactivation to promote the reversion of pathological inflammations or provoking protective innate and/or adaptive immunity to inhibit pathogenic invaders. Third, we highlight the applications of surface-modified bacteria as multifunctional living therapeutics in disease treatment, especially alleviating inflammatory bowel diseases via oral delivery and intervening in different types of cancer through systemic or intratumoral injection. Finally, we discuss the challenges and prospects of dopamine polymerization-mediated multifunctionalization for preparing advanced bacterial therapeutics as well as their bench to bedside translation. We anticipate that this Account can provide an insightful overview of bacterial therapy and inspire innovative thinking and new efforts to develop next-generation living therapeutics for treating various diseases.

Influence of core-shell polydopamine-barium titanate doping on the osseointegration and cytotoxicity of the polypyrrole coatings applied by ECD on Nitinol orthopedic implants

In the current study, a thin polydopamine (PDA) layer of around 5 nm was created on the barium titanate (BT) nanoparticles through self-polymerization of dopamine. The produced modified PDA/BT core-shell nanoparticles, termed PBT, were co-electrodeposited with polypyrrole (PPy) onto Nitinol (NiTi) alloy substrates in concentrations ranging from 1 to 10% by weight to produce PPy/PBT composite coatings. The incorporation of these particles changed PPy's cauliflower morphology into a rougher but more compact nodular morphology. According to the atomic force microscopy results, the average surface roughness of PPy coating increased from 44.2 nm up to 80.2 nm by the co-deposition of PBT. Aside from variations in morphology and roughness values, all of the PPy and PPy/PBT coatings demonstrated hydrophilicity. Nonetheless, while the majority of the composite coatings had higher water contact angle (WCA) than the unreinforced PPy, the PPy/10PBT composite coating had the lowest WCA of all samples, measuring 56.9°. The piezoelectric responses of the coatings were also examined, and the best specimen was the PPy/5PBT composite coating with an enhanced output voltage of approximately 400 mV. Finally, MC3T3 mouse osteoblast cells were used for in vitro cell culture evaluations. While healthy cells were evenly distributed on the surface of all coatings after 3 days, indicating biocompatibility, cell density on composite coatings was higher than on unreinforced PPy coating. According to the MTT experiment, the vitality of MC3T3 osteoblast cells on the surface of PPy/5PBT composite coating was more than 30% greater than that on the surface of PPy coating.

Mesoporous Silicon Nanoparticles with Liver-Targeting and pH-Response-Release Function Are Used for Targeted Drug Delivery in Liver Cancer Treatment.

This article aims to develop an aspirin-loaded double-modified nano-delivery system for the treatment of hepatocellular carcinoma. In this paper, mesoporous silica nanoparticles (MSN) were prepared by the "one-pot two-phase layering method", and polydopamine (PDA) was formed by the self-polymerization of dopamine as a pH-sensitive coating. Gal-modified PDA-modified nanoparticles (Gal-PDA-MSN) were synthesized by linking galactosamine (Gal) with actively targeted galactosamine (Gal) to PDA-coated MSN by a Michael addition reaction. The size, particle size distribution, surface morphology, BET surface area, mesoporous size, and pore volume of the prepared nanoparticles were characterized, and their drug load and drug release behavior in vitro were investigated. Gal-PDA-MSN is pH sensitive and targeted. MSN@Asp is different from the release curves of PDA-MSN@Asp and Gal-PDA-MSN@Asp, the drug release of PDA-MSN@Asp and Gal-PDA-MSN@Asp accelerates with increasing acidity. In vitro experiments showed that the toxicity and inhibitory effects of the three nanodrugs on human liver cancer HepG2 cells were higher than those of free Asp. This drug delivery system facilitates controlled release and targeted therapy.

Disposable Point-of-Care Electrochemical Sensor for Uric Acid Determination in Human Urine Utilizing a Pencil Graphite Electrode Modified with Polydopamine/Gold Nanoparticles

Point-of-care testing (POCT) is an essential approach in clinical analysis due to its rapidity. In the current research and for the first time, we have developed an electrochemical POC sensor for uric acid (UA) determination using pencil graphite electrode (PGE) substrate modified via a facile self-polymerization of dopamine (DA). Alkaline conditions were used to produce polydopamine (PDA) which inspired from mussel adhesive protein. The PDA-modified electrode was further decorated by electrodeposition of gold nanoparticles (Au-NPs). Sensor surface characterization was conducted using surface characterization techniques like X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) imaging. In addition electrochemical characterization methods were performed utilizing electrochemical impedance spectroscopy (EIS) as well as cyclic voltammetry (CV). The sensor yielded a precise voltammetric response upon using differential pulse voltammetry (DPV) (linearity range: 5.0 × 10−5 mol l−1 − 5.0 × 10−4 mol l−1 of UA with 1.57 × 10–5 mol l−1 limit of detection). The developed sensor’s benefits include decreased manufacturing cost and selectivity. Accurate and satisfactory results were obtained upon application to human urine sample analysis.

Establishment of Polydopamine-Modified HK-2 Cell Membrane Chromatography and Screening of Active Components from Plantago asiatica L.

Cell membrane chromatography (CMC) has been widely recognized as a highly efficient technique for in vitro screening of active compounds. Nevertheless, conventional CMC approaches suffer from a restricted repertoire of cell membrane proteins, making them susceptible to oversaturation. Moreover, the binding mechanism between silica gel and proteins primarily relies on intermolecular hydrogen bonding, which is inherently unstable and somewhat hampers the advancement of CMC. Consequently, this investigation aimed to establish a novel CMC column that could augment protein loading, enhance detection throughput, and bolster binding affinity through the introduction of covalent bonding with proteins. This study utilizes polydopamine (PDA)-coated silica gel, which is formed through the self-polymerization of dopamine (DA), as the carrier for the CMC column filler. The objective is to construct the HK-2/SiO2-PDA/CMC model to screen potential therapeutic drugs for gout. To compare the quantity and characteristics of Human Kidney-2 (HK-2) cell membrane proteins immobilized on SiO2-PDA and silica gel, the proteins were immobilized on both surfaces. The results indicate that SiO2-PDA has a notably greater affinity for membrane proteins compared to silica gel, resulting in a significant improvement in detection efficiency. Furthermore, a screening method utilizing HK-2/SiO2-PDA/CMC was utilized to identify seven potential anti-gout compounds derived from Plantago asiatica L. (PAL). The effectiveness of these compounds was further validated using an in vitro cell model of uric acid (UA) reabsorption. In conclusion, this study successfully developed and implemented a novel CMC filler, which has practical implications in the field.

Rapid UV-curable preparation of durable soybean oil-based superhydrophobic anti-icing surfaces with excellent photothermal deicing property

Photothermal superhydrophobic coatings are promising for anti-icing/deicing. However, preparing such coatings from environmentally friendly and sustainable strategies is challenging. Herein, a bio-based and durable photothermal superhydrophobic coating is prepared via layer-by-layer strategy. Bio-based methacrylic acid epoxidized soybean oil oligomers are synthesized as an alternative to petroleum-based binders. Meanwhile, efficient photothermal conversion of hydrophobic particles are enabled by oxidative self-polymerization of dopamine to decorate hydrophobic silica particles grafted with hydrophobic long-chain alkanes and photo-curable methacrylic acid moieties. Ultimately, the superhydrophobic coating is achieved by spraying photothermal hydrophobic particles onto an oxygen-inhibited layer of pre-cured bio-based binder followed by thorough photocuring treatment. The coating exhibits powerful water repellency (WCA of 158.2 ± 1.6°, SA of 4.6 ± 0.8°), good robustness, chemical and UV irradiation resistance. Moreover, under NIR laser irradiation (808 nm, 1 W/cm2), the coating features excellent photothermal conversion efficiency (ΔT of 41.0 °C at 30 s) and stable photothermal conversion performance. And in frigid conditions (-15 °C, ∼73 ± 5 % RH), the coating delivers rapid defrosting (few seconds) and deicing (20 μL water droplet melts in 42 s) performance under NIR irradiation of 1 W/cm2. Therefore, the as-prepared coating provides valuable insight into global anti-icing/deicing action.

Polydopamine chelating strontium on graphene oxide enhances the mechanical and osteogenic induction properties of PLLA/PGA bone scaffold

Poly (lactic acid)/poly (glycolic acid) (LG) bone scaffold exhibits good biocompatibility for bone defect regeneration but lacks satisfactory mechanical and osteogenic induction properties. Here, graphene oxide (GO) was encapsulated by polydopamine (PDA) via self-polymerization of dopamine, and strontium (Sr) was loaded onto GO by the chelation of PDA. The modified GO was added to the LG scaffold prepared via selective laser sintering as a reinforcing phase to improve the mechanical properties and osteogenic induction properties. The results indicated that the tensile and compressive strengths of the scaffold with 1.5 wt% modified GO were 9.49 MPa and 19.22 MPa, respectively, representing 67.08% and 95.33% improvement compared to the LG scaffold. The enhancement mechanisms of the modified GO in the scaffold included crack branching, crack deflection, crack pinning, crack bridging, and pulling out. More importantly, the scaffold with modified GO exhibited superior bioactivity and osteogenic induction properties compared to the LG scaffold, because PDA could chelate calcium ions derived from the surrounding physiological environment, and the calcium ions attracted phosphate ions through electrostatic interactions to promote the apatite layer deposition. Additionally, the presence of Sr in the scaffold promoted the proliferation and differentiation of osteoblasts, thereby improving osteogenic induction properties.

Preparation of carbon-coated Fe2 O3 @Ti3 C2 Tx composites by mussel-like modifications as high-performance anodes for lithium-ion batteries.

Fe2 O3 with high theoretical capacity (1007 mA h g-1 ) and low cost is a potential anode material for lithium-ion batteries (LIBs), but its practical application is restricted by its low electrical conductivity and large volume changes during lithiation/delithiation. To solve these problems, Fe2 O3 @Ti3 C2 Tx composites were synthesized by a mussel-like modification method, which relies on the self-polymerization of dopamine under mild conditions. During polymerization, the electronegative group (-OH) on dopamine can easily coordinate with Fe3+ ions as well as form hydrogen bonds with the -OH terminal group on the surface of Ti3 C2 Tx , which induces a uniform distribution of Fe2 O3 on the Ti3 C2 Tx surface and mitigates self-accumulation of MXene nanosheets. In addition, the polydopamine-derived carbon layer protects Ti3 C2 Tx from oxidation during the hydrothermal process, which can further improve the electrical conductivity of the composites and buffer the volume expansion and particle agglomeration of Fe2 O3 . As a result, Fe2 O3 @Ti3 C2 Tx anodes exhibit ~100 % capacity retention with almost no capacity loss at 0.5 A g-1 after 250 cycles, and a stable capacity of 430 mA h g-1 at 2 A g-1 after 500 cycles. The unique structural design of this work provides new ideas for the development of MXene-based composites in energy storage applications.

3D printed composites based on the magnetoelectric coupling of Fe/FeCo@C with multiple heterogeneous interfaces for enhanced microwave absorption

In this paper, the ZIF-derived carbon nanoskeleton was cleverly introduced into the carbonyl iron surface by in situ self-polymerization of dopamine on the carbonyl iron surface to build a “bridge” and multiple heterogeneous interfacial wave-absorbing agents of Fe/FeCo@C were obtained by heat treatment process. The large amount of polarization loss introduced by the designed multi-heterogeneous interfaces increases the ability of the material to attenuate electromagnetic waves. At the same time, the conductive network formed by loading nanoparticles with the lamellar structure of micrometal is employed to couple the dielectric loss depletion and the magnetic loss together, and the electromagnetic parameters are regulated by graphitization. The FDM technique was utilized to prepare filaments that can be used for 3D printing by compositing the wave absorber with PP resin and to explore the effect of FCC/PP composites on the attenuation of electromagnetic waves by utilizing dielectric-electromagnetic coupling realizations. The results show that the preparation yields an adequate absorption bandwidth of 4.75 GHz at 1.5 mm for FCC-3/PP at 40 % fill ratio, and the minimum reflection loss can reach close to −60 dB at 1.7 mm. The wave-absorbing composite materials can also be utilized to print various shaped materials, and this work provides a new option for preparing electromagnetic-absorbing composites by FDM 3D printing in the future.