Polydopamine Research Articles

Antimicrobial GL13K Peptide-Decorated ZnO Nanoparticles To Treat Bacterial Infections.

As a broad-spectrum antimicrobial material, ZnO nanoparticles (NPs) offer a novel approach to infected wounds in the clinic; however, it is very necessary to improve the antimicrobial performance of ZnO to satisfy the clinic requirements. In this work, a new antimicrobial hybrid ZnO@PDA/GL13K was prepared by attaching the antimicrobial GL13K peptide on the surface of ZnO NPs via polydopamine (PDA) as a covalent bonding agent, which can enhance the reactive oxygen species (ROS) production and damage the cell wall, showing superior antimicrobial efficacy. Besides, the ZnO@PDA/GL13K hybrid can promote the healing of bacterial infected wounds, with the wound area only remaining 1.8% on day 9, about 2 times smaller than that of the ZnO group. Moreover, ZnO@PDA/GL13K also showed good biocompatibility, and no side effect on normal tissue and organs was found, implying that the antimicrobial hybrid may possess prospective application in biomedical fields.

Interfacially Cross-Linked Polydopamine/Polybenzimidazole Composite Membranes for Organic Solvent Nanofiltration.

Interfacial cross-linking was used to prepare composite organic solvent nanofiltration (OSN) membranes comprising a polydopamine (PDA) active layer formed on a polybenzimidazole (PBI) substrate. Dibromo-p-xylene (DBX) was employed as a cross-linking agent to make the composite membranes chemically stable against harsh polar aprotic solvents. The interfacial cross-linking of PDA/PBI allowed for finely tuning the molecular weight cutoff (MWCO) of the membrane, resulting in a membrane with precise molecular separation capabilities for OSN. The morphology and surface properties of the membranes were characterized, and a membrane with a MWCO of 286 Da was investigated for OSN of a series of solvents. The membrane permeance was in the order of acetonitrile (MeCN) > methanol (MeOH) > acetone > toluene > dimethylformamide (DMF) > heptane > ethanol (EtOH) > isopropanol (IPA) > tetrahydrofuran (THF). The membranes displayed a sharp pore size distribution, yielding a rejection rate of over 99% for Rose Bengal (RB, MW 1020 g/mol) and Remazol brilliant blue (RBB, MW 626.5 g/mol) from DMF and EtOH solutions. When it came to methyl orange (MO, MW 327.3 g/mol) that had a molecular weight closer to the MWCO of the membrane, the membrane still displayed a high rejection rate of 95% and 99% in nanofiltrating solvents DMF and EtOH, respectively. In addition, it was demonstrated that the membrane was able to effectively fractionate mixed solutes having molecular weights appropriate for the MWCO rating of the membrane during OSN.

Polydopamine-modified MXene-integrated photothermal responsive hydrogel for constructing rapid photothermal and self-sensing gradi- ent hydrogel actuators

Abstract PNIPAm-based stimuli-responsive hydrogel actuators have made significant progress. By introducing responsive modules such as photothermal nanoparticles, the hydrogel can respond to environmental changes and construct anisotropic structures, allowing the hydrogel actuators to quickly bend and realize complex shape deformation. How-ever, there remains a need to enhance the mechanical properties of these hydrogels to accommodate multiple deformation actions and different application scenarios, and enhance the compatibility between nanoparticles and the hydrogels to improve the comprehensive performance of materials are still issues that need to be solved. In this study, we modified two-dimensional MXene nanosheets with polydopamine (PDA) to obtain P-MXene, which served as a photothermal agent and can be stably dispersed within the hydrogel system. We copolymerized thermosensitive N-isopropylacrylamide (NIPAm) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) in situ and used a direct current (DC) electric field to induce a concentration gradient distribution of P-MXene nanosheets within the hydrogel, resulting in the preparation of anisotropic gradient hydrogel actuators with good stretchability and conductivity. The hydrogel structure was characterized using scanning electron microscopy (SEM) and the Fourier transform infrared (FTIR) spectra. The swelling properties, mechani-cal properties and conductivity of the hydrogel were studied. The actuation behavior of P(NIPAm-DMAEMA)/P-MXene gradient hydrogel actuators under different thickness and electric field intensity was investigated. Additionally, the sensitivity and stability of the conductive hydrogel actuators were tested. and the functions of monitoring human health and information transmission were realized. It integrated with rapid photo responsiveness and self-sensing capabilities to monitor the defor-mation process of the actuators through real-time relative resistance changes during the actuations. This work is expected to expand the application field of soft hydrogel actuators and provide new insights into the design of a new generation of soft robots.

Trojan Horse Strategy for Wireless Electrical Stimulation-Induced Zn2+ Release to Regulate Neural Stem Cell Differentiation for Spinal Cord Injury Repair.

Due to the uncertain differentiation of neural stem cells (NSCs), replenishing lost neurons by endogenous neural differentiation to repair spinal cord injury (SCI) remains challenging. The electrical stimulation-induced drug release is a promising approach for the localized and controlled release of drugs to regulate the differentiation of NSCs into neurons. Here, we developed Zn-PDA@BT nanoparticles acted as Trojan Horse to enter cells through endocytosis for Zn2+-controlled release therapy by the potentials generated by the piezoelectric effect. Due to the presence of polydopamine (PDA), under ultrasound stimulation, the electrical signal derived from the piezoelectric effect of barium titanate nanoparticles can be attracted to the surface of Trojan Horse nanoparticles to facilitate the controlled release of Zn2+. And Zn2+ bonded with PDA can increase the intracellular Zn2+ concentration within mouse-derived NSCs (mNSCs) to regulate the differentiation of mNSCs, which could enhance excitatory neuronal differentiation and inhibit astrocyte differentiation of mNSCs by activating the TGF-β and p53 pathways. More importantly, this Trojan Horse therapy allowed mNSCs to differentiate into mature neurons in 5 days, while the natural differentiation process took 10 days. Moreover, the transplantation of mNSC-ingested Zn-PDA@BT nanoparticles effectively replenished lost neurons at the damaged site and promoted function recovery after SCI in vivo, demonstrating the great potential of electrical stimulation-induced Zn2+ release for SCI repair.

Understanding of Polydopamine Formulation for Oral Therapeutic Delivery in Ulcerative Colitis Treatment

AbstractOral therapeutic delivery remains challenged by gastrointestinal tract (GI) barriers, which hinders the successful transition of therapeutic candidates into clinical treatments. Polydopamine (PDA), with its versatile ability to overcome GI barriers, offers a promising drug formulation technology to address the challenge. Nevertheless, many critical questions remain unanswered regarding the practicality of PDA‐based formulations. Building on the previous research, which tackled multiple physicochemical aspects, the current study aims to address another three outstanding issues, including the quantification of residual dopamine (DA) in PDA‐based formulations, the examination of these formulations stimulatory effects on colon tissue, and the potential anti‐inflammatory properties. To facilitate this investigation, a curcumin‐containing nanomedicine (CP@CCS) is prepared as a representative PDA‐based formulation. The results reveal a marked decrease of residual DA within the formulation. In the treatment of ulcerative colitis (UC), the formulation do not provoke the substantial contractions in colon tissue typically induced by DA. Furthermore, in vivo evaluation verified the supplementary anti‐UC benefits of PDA. These outcomes add evidence for the practicality of PDA‐based formulations in terms of safety and therapeutic efficacy. Finally, a conceptual framework is proposed for understanding the role of PDA in oral therapeutic delivery, thereby providing insightful directions for subsequent research.

A biomimetic approach towards a universal slippery liquid infused surface coating.

One biomimetic approach to surface passivation involves a series of surface coatings based on the slick surfaces of carnivorous pitcher plants (Nepenthes), termed slippery liquid-infused porous surfaces (SLIPS). This study introduces a simplified method to produce SLIPS using a polydopamine (PDA) anchor layer, inspired by mussel adhesion. SLIPS layers were formed on cyclic olefin copolymer, silicon, and stainless steel substrates, by first growing a PDA film on each substrate. This was followed by a hydrophobic liquid anchor layer created by functionalizing the PDA film with a fluorinated thiol. Finally, perfluorodecalin was applied to the surface immediately prior to use. These biomimetic surface functionalization steps were confirmed by several complimentary surface analysis techniques. The wettability of each surface was probed with water contact angle measurements, while the chemical composition of the layer was determined by X-ray photoelectron spectroscopy. Finally, ordering of specific chemical groups within our PDA SLIPS layer was determined via sum frequency generation spectroscopy. The hemocompatibility of our new PDA-based SLIPS coating was then evaluated by tracking FXII activation, fibrin generation time, clot morphology, and platelet adhesion to the surface. This hemocompatibility work suggests that PDA SLIPS coatings slow or prevent clotting, but the observation of both FXII activation and the presence of adherent and activated platelets at the PDA SLIPS samples imply that this formulation of a SLIPS coating is not completely omniphobic.

Structural Modifications on Dopamine Molecules toward Polydopamine Applications

Polydopamine (PDA) is a synthetic material synthesized through the oxidative self‐polymerization of dopamine under alkaline conditions. This material emulates the adhesive properties of mussel foot proteins, allowing the formation of robust and stable organic coatings on various surfaces. Researchers have attempted to identify and improve the surface‐coating properties of PDA by incorporating additional organic functional groups. This review explores the structural modifications of dopamine molecules at the organic chemistry level, with a focus on changes in the catechol moiety and aliphatic amines, and examines their impact on the applications of PDA. The flexibility of these modifications underscores their importance for optimizing PDA coatings for a wide range of applications.

Synergistic catecholamine and coordination chemistry for enhanced bioactivity and secondary grafting activity of zirconia dental implants

The inherent bioinertness of zirconia (ZrO2) hinders its early bone integration, presenting a significant obstacle to its widespread use in dental implant technologies. Addressing this, we developed a surface coating leveraging the synergistic effects of catecholamine and coordination chemistry inspired by the mussel byssus cuticle. This coating, named PDPA@Sr, is enriched with strontium ions and amine groups, resulting from a simple immersion of polydopamine (PD)-coated ZrO2 in an alkaline strontium chloride and poly(allylamine) (PA) solution. Compared to conventional mussel-inspired PD coatings, PDPA@Sr demonstrates enhanced aesthetic properties and mechanical stability. The continuous release of strontium ions from the coating significantly enhances osteogenesis, while the abundant surface amine groups offer notable antibacterial effects. More importantly, these amine groups also enable a variety of chemical modifications, including electrostatic adsorption, carbodiimide chemistry, Michael addition, Schiff base formation, and click chemistry, thus providing a multifaceted platform for the advanced surface modification of ZrO2 implants.

A systematic study on Au-PDA@Fe3O4 core-shell catalysts for enhanced catalytic reduction of 4-nitrophenol

The development of nanogold catalysts with high activity and high stability is of great significance for their industrial applications. In this paper, Au-PDA@Fe3O4 catalysts were prepared through the gold sol adsorption method. First, micron-sized magnetic Fe3O4 spheres were synthesized via a solvothermal method, serving as the core to endow the catalyst with excellent recyclability. Subsequently, a layer of polydopamine (PDA) shell was polymerized on the magnetic core surface. By controlling the timing of introducing the gold sol containing Au nanoparticles (NPs), the spatial position of Au NPs within the PDA layer was regulated, leading to a series of magnetic core-shell nano gold catalysts with varying spatial positions of Au. Using the 4-nitrophenol (4-NP) hydrogenation as the probe, the influence of Au spatial position, Au size, and other conditions on the catalytic performance was investigated. Results showed that, in the prepared Au-PDA@Fe3O4-16 catalyst, the Au NPs are encapsulated within the PDA shell and positioned close to the outer layer. This not only provides remarkable stability to the Au NPs but also maintains their proximity to the surface of the PDA shell, allowing easier access of the substrate 4-NP to the Au NPs and conferring good reactivity upon the catalyst. The strong electron metal-support interaction between PDA and Au enables PDA to effectively stabilize Au NPs. The prepared Au-PDA@Fe3O4-16 catalyst exhibits excellent stability, maintaining a high conversion rate of 91% even after 14 cycles of use. Our findings not only deepen the understanding of the catalytic mechanisms involved but also pave the path towards the creation of highly efficient and robust gold-based catalysts, facilitating their widespread utilization in industrial applications.

2D hollow leaf shaped mesoporous carbon derived from ZIF-L for efficient capacitive deionization

Electrochemical treatment of saline or brackish water by capacitive deionization (CDI) is a novel resource-saving solution to ensure the availability of freshwater resources in the environment. MOF (metal–organic framework) derived carbon as a novel carbonaceous material in CDI has received considerable research attention. Among them, ZIF-L-derived carbon (ZC) suffers from problems such as self-aggregation, poor mesoporous structure, and low electrical conductivity, which lead to poor CDI performance. In this paper, a strategy of ZIF-L coated with polydopamine (PDA) is proposed to solve the above problems. When the amount of PDA was 0.5 g, ZIF-L@PDA0.5-derived carbon composite (ZPC0.5) is obtained for efficient capacitive deionization. The ZPC0.5 composite not only maintains the 2D leaf shaped structure consistent with ZIF-L, exposing more active sites, but also has an elevated mesopore occupancy ratio to promote solution diffusion. Meanwhile, the interaction between PDA and ZIF-L makes the ZPC0.5 have a cavity structure, which improves the mass transfer capacity. The resulting ZPC0.5 composite has a specific capacitance (165.8F g−1) that is 3.86 times higher than that of ZC (42.9F g−1). Consequently, in 1.2 V, 500 mg/L NaCl solution, the symmetric CDI cell ZPC0.5//ZPC0.5 exhibits an excellent desalination capacity (29.6 mg/g), which is 2.69 times that of the ZC//ZC.

Novel N-doped carbon nanotubes impregnated Mn spheres with polydopamine coating as an efficient polysulfide immobilizer for Li-S batteries

Lithium-sulfur (Li-S) batteries are one of the most promising energy storage and conversion devices due to the high theoretical capacity and cost-effectiveness of sulfur. However, they still suffer from sluggish redox kinetics and the shuttle effect caused by complex polysulfides. In this work, graphitic carbon nitride (g-C3N4) is utilized as a template and further hydrothermally treated with an Mn source and glucose. The pyrolysis of g-C3N4 gives rise to N-doped carbon nanotubes, producing abundant sites for physical confinement and chemical adsorption of polysulfides, while glucose carbonization brings forth amorphous carbon and Mn source produces metal spheres. Afterward, polydopamine (PDA) induces N-doped carbon coating and promotes interface connection as well as electron immigration. This synergistic design possesses a high surface area of micropores and mesopores to aggregate sulfur and accelerate redox kinetics. As a result, the N-doped carbon nanotube with Mn spheres and PDA coating@sulfur (CN/Mn-PDA@S) exhibits a high reversible capacity of 813.5 mAh g−1 at 1 C with a decay rate of 0.064% per cycle and remarkable capacity retention at 2 C with rate performance up to 4 C. Therefore, the novel design of N-doped carbon nanotubes with Mn spheres and PDA coating serves as an efficient polysulfide immobilizer for Li-S batteries.

A new strategy to prepare bio-based polylactic acid modifier for multi-functionality: Dopamine-grafted modified lignin

Currently, to address the performance deficiencies associated with high brittleness, inadequate thermal stability, and susceptibility to hydrolysis in polylactic acid (PLA), it is common practice to incorporate multiple or high proportions of additives. However, this approach raises concerns regarding interface compatibility, energy consumption, and environmental impact. In this context, we introduce an environmentally friendly, bio-based PLA modifier that is facile to prepare and facilitates multi-functional applications at a minimal dosage. The presence of a benzene ring structure in lignin endows the material with ultraviolet (UV) resistance, thermal stability, and hydrophobic characteristics, while the exceptional adhesion properties of polydopamine (PDA) enhance interfacial compatibility. A novel biomass polylactic acid modifier, designated as OL@PDA, has been synthesized by modifying low-molecular-weight lignin (OL) with PDA. Comparative analysis of OL@PDA/PLA composite materials reveals a 14.08 % increase in tensile strength and a 42.00 % enhancement in elongation at break relative to pure PLA. The incorporation of the lignin-derived benzene ring structure effectively transforms PLA from a hydrophilic to a hydrophobic material. Furthermore, the UV transmittance at 400 nm (T400 nm%) is recorded at 65.8 % for pure PLA, which significantly decreases to below 5 % for OL@PDA/PLA composites. The integration of OL@PDA as a modifier in PLA materials yields comprehensively performance enhancements while maintaining a low additive concentration.

Polydopamine-incorporated MOF membrane with hydrophilicity for effective oil/water separation and fouling-resistant model analysis and prediction

A large number of oil spills and oily wastewater are discharged, in the modern industrial production process, resulting in serious water pollution. Oily wastewater can be extremely harmful to ecosystems and human health. Oil-water separation has become a major challenge at present, and membrane separation has aroused more and more concern in recent years due to its high economic efficiency. This paper fabricated PES filtration membranes using the novel nanoparticlesbased on both metal–organic frameworks-5 (MOF-5) and polydopamine (PDA) layers as dopants, and then adequately explored the porosity, morphology, separation, hydrophilicity, and fouling-resistant performance of the resultant membranes. In addition, the prepared membranes were used for oil–water separation, including soybean-in-water, petroleum ether-in-water, and gasoline-in-water emulsions. MOF@PDA membranes exhibit high separation efficiency of up to 99.8%. Subsequently, membrane fouling mechanisms were investigated using the Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, and the molecular mode of interaction with the three oil–water emulsions with the membrane was compared. Newly prepared MOF@PDA membranes have better stability, fouling-resistant, and self-cleaning properties. Finally, an optimal machine learning model for oil–water separation efficiency was developed with a high prediction accuracy of 98%. The obtained results indicate that mixed matrix membranes exhibit excellent oil–water separation performance, demonstrating great application prospects in the remediation of oily wastewater.

Multi-quenching electrochemiluminescence system based on resonance energy transfer from self-enhanced Ce(III, IV)-MOF@Ru to CuO@PDA@AuNPs for ultrasensitive detection of HER2

This study presents an innovative approach based on electrochemiluminescence resonance energy transfer (ECL-RET) through the introduction of a new pattern donor-acceptor couple. The donor of self-enhanced Ce(III, IV)-MOF@Ru is created by immobilizing Ru(bpy)32+ on Ce-based metal-organic frameworks (Ce(III, IV)-MOF). The acceptor of CuO@PDA@AuNPs is the CuO nanospheres polydopamine (PDA) framework grafted with gold nanoparticles (AuNPs). An ultrasensitive detection of human epidermal growth factor receptor-2 (HER2) was achieved through the development of a quenched ECL immunosensor. Ce(III, IV)-MOF, a unique 3D infinite extension framework, was recognized for its excellent nanostructure and remarkable capacity to greatly activate tripropylamine (TPrA) and generate abundant radicals. Fortunately, it was simultaneously utilized as a highly effective coreactant accelerator and encapsulation agent, thereby facilitating the immobilization of Ru(bpy)32+ and the generation of radicals for creating a self-enhanced emitter of Ce(III, IV)-MOF@Ru. Consequently, by effectively reducing the distance of electron transmission and minimizing the loss of energy, Ce(III, IV)-MOF@Ru achieved a significantly high efficiency in ECL. More importantly, CuO@PDA@AuNPs was prepared as a perfect quenching agent. The ultraviolet-visible (UV–vis) spectra of CuO@PDA@AuNPs exhibited partial overlap with ECL spectra of Ce(III, IV)-MOF@Ru, thus efficiently initiating the ECL-RET interaction between the donor and acceptor. With the purpose of demonstrating the superiority of newly obtained self-enhanced nanoemitter and donor-acceptor couple, an ECL immunoassay was proposed for the analysis of HER2 with range of 0.2 fg/mL ∼ 10 ng/mL and the limit of detection of 0.067 fg/mL. Therefore, this method supplies convenient and significant strategy for the clinical analysis.

Improved tribological properties of MXene nanosheet filler-modified PPO composites

MXenes, a class of two-dimensional (2D) nanomaterials, exhibit exceptional properties such as outstanding mechanical and thermal stability, along with diverse surface characteristics, making them highly promising in the tribology. However, their tendency to aggregate within the polymeric matrix adversely affects the tribological performance of the polymer. In this study, glass fiber (GF) surfaces were modified with polydopamine (PDA), allowing smaller MXene nanosheets to adhere to the GF surface, whereas the larger MXene nanosheets were dispersed throughout the matrix. This approach effectively enhanced the dispersion of MXene nanosheets in the polymeric matrix, facilitating the preparation of polyphenylene oxide (PPO)/MXene composite materials. Compared with the pure PPO sample, the results showed that the average friction coefficient and wear rate of the PPO/MXene composites were reduced by 46.25% and 98.34%, respectively, due to the distinct roles of different MXene nanosheet sizes in the polymeric matrix. Furthermore, a uniform lubricating film was formed during the friction of the polymer composite, enhancing its tribological performance. This study proposes a novel design strategy to enhance MXene nanosheet dispersion and optimize their lubricating properties.

Antimicrobial effects of peptides from fenugreek and ginger proteins using Fe3O4@PDA-MWCNT conjugated trypsin by improving enzyme stability & applications

Trypsin was immobilized onto a newly formulated nanocomposite (NC) comprising magnetic (Fe3O4) multiwalled carbon nanotubes (MWCNTs) anchored with polydopamine (PDA). The fabricated NC and the NC-bound trypsin were subjected to comprehensive characterization using various biophysical techniques including Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and fluorescence spectroscopy. The NC-bound trypsin exhibited significantly enhanced thermostability and increased tolerance to various organic solvents and denaturants. The enzymatic activity of trypsin was notably augmented through its coupling with the nano support, yielding an effectiveness factor (η) of 2.65. Fenugreek and ginger protein hydrolysates, prepared using both native and NC-bound enzyme, were evaluated for their antimicrobial activities. The analysis revealed that peptides generated by NC-bound trypsin showed higher antimicrobial activity (~ 10) in most cases compared to peptides obtained by using native trypsin. This strategy presents an innovative methodology for the production of potential biopeptides, with the prospect of their incorporation into pharmaceutical and therapeutic sectors through the utilization of NC-bound trypsin in protein hydrolysis.

Multi-core–shell nanoboxes comprising polydopamine-derived C coated NiCo@C and FeCo@C nanohybrid for enhanced electrochemical quantification of nitrofurantoin

The development of a high-performance electrochemical sensing platform for monitoring nitrofurantoin (NFT) levels in various real samples plays an important role in the research community worldwide. To accomplish this objective, the crucial challenge is to construct sensing interfaces with outstanding electrocatalytic capabilities. In the present work, a highly efficient metal@carbon electrocatalyst with porous and multi-core–shell nanobox structure comprising polydopamine (PDA)-derived C coated NiCo@C and FeCo@C nanohybrid (named as NiCo@C/FeCo@C@C) was fabricated by simply pyrolyzing NiCo@FeCo Prussian blue analogues (PBA)@PDA. The carbonization of PDA into carbon shells protected the framework from collapsing during high-temperature pyrolysis process, thus enlarging the specific surface areas and porosity. The NiCo@C/FeCo@C@C composite attained an enhanced electrochemical capability, such as an outstanding electronic conductivity from the double carbon shell with porous structure, a large number of active sites and a high electrocatalytic activity from the metallic alloy nanoparticles, which exhibited a highly sensitive response to NFT. Under optimized experimental conditions, the established NiCo@C/FeCo@C@C electrochemical sensor displayed a wide linear range of 0.05–100 μM for NFT determination, coupled with a low detection limit of 14 nM. The practical feasibility of this sensor was also confirmed by the analysis of NFT in tablet and lake water samples with outstanding recovery rates. Moreover, the sustainability of the sensor was demonstrated through its prominent performance in high reproducibility, selectivity and long-term stability. This study thus introduces an innovative approach for the advance of highly efficient electrocatalysts in the area of electrochemical sensing.

Reactive oxygen species augmented polydopamine-chlorin e6 nanosystem for enhanced chemo/photothermal/photodynamic therapy: A synergistic trimodal combination approach in vitro & in vivo

Amalgamation of near-infrared laser phototherapies with chemotherapy in multi-modal synergistic therapy holds great promise for future precision cancer nanomedicine due to its minimal invasiveness, reduced adverse reactions, and high anticancer efficacy. Herein, CuO nanoparticles were functionalized with photosensitizer molecule, chlorin e6 (Ce6) and coated with polydopamine (PDA) to achieve a drug delivery system (CuO@Ce6-PDA) with photothermal/photodynamic therapy (PTT/PDT). Subsequently, chemical drug PTX was loaded for chemotherapy, and folic acid (FA) serving as cancer-targeting exterior material. Prepared FA@CuO@Ce6-PDA/PTX nanoparticles were nano-sized with favorable biocompatibility, colloidal stability, optimal surface charge, effective PTX loading, and controllable PTX release. In vitro studies on 4 T1 cells showed that FA@CuO@Ce6-PDA/PTX had noteworthy synergistic therapeutic antitumour effects featuring chemo/PTT/PDT with IC50 of 50 μg/mL lower than that FA@CuO@Ce6-PDA/PTX without NIR laser irradiation (225 μg/mL). Additionally, FA@CuO@Ce6-PDA/PTX produced intracellular high reactive oxygen species (ROS) in presence of 660 nm laser, altering mitochondrial membrane potential and promoting tumour cell death. In vivo results indicate nanoplatform could accumulate in tumour spots enabling thermal imaging capabilities and exhibit synergistic therapeutic effect if irradiated with NIR laser (808 and 660 nm), evident from in vitro antitumour assay. Therefore, in vitro finding postulates FA@CuO@Ce6-PDA/PTX could be an intriguing nanoplatform for Chemo/PTT/PDT-based combination therapy.

A sequential treatment strategy by copper ion-doped nanofiber dressing for highly efficient biofilm combating and rapid wound healing

Copper ions are considered as a promising alternative to combat infected wound and accelerate wound healing. However, exhibiting good antibiofilm activity meanwhile minimizing cell toxicity remains a great challenge. To address this issue, we provide a sequential treatment strategy to combat biofilm infected wound with low copper ion (Cu2+) release (as low as 1.2 μg·mL−1). Polydopamine (PDA) adherent copper ion complex is constructed on thermoplastic polyurethane (TPU) to develop the Cu2+@PTPU nanofibers. With the application of Cu2+@PTPU wound dressing, nitric oxide (NO) gas is released by catalyzing endogenous donor, thereby rapidly eliminating more than 90 % biofilm biomass. Subsequent moderate photothermal treatment (∼47℃) significantly enhanced bactericidal effect by deconstructing bacteria membrane. As a result, the biofilm infection was eradicated in only ∼ 6h, significantly more effective than existing methods (∼24 h). Additionally, Cu2+@PTPU dressing not only exhibits excellent cell compatibility, but also promotes wound healing. In vivo study demonstrates that it reduces the level of inflammatory responses by 104 % and increases angiogenesis capacity by 115 %, compared with untreated group, thereby narrowing the wound site area by 72 % at day 14 after treatment. Overall, the Cu2+@PTPU dressing and sequential treatment strategy provide quick, safe, yet efficacious biofilm combating outcomes and facilitates rapid wound healing.

Electrophoretic deposition of novel antibacterial and biocompatible polydopamine and ZIF-8 hybrid composite coating on anodized Ti-6Al-4V alloy with silane primary substrate

Production of biocompatible and corrosion resistance dental implant is a requirement in the modern dental science. In this work, the Ti-6Al-4V was used alloy for the dental implant application that has investigated to make it more corrosion resistive and antibacterial with electrophoretic deposition of silane precursor solution that made of acidic solution of tetraethyl orthosilicate (TEOS) and methyl three ethoxy silane (MTES). The optimized silane coating has been achieved with 30 V, 30 min and at 100 °C ramped annealing by comparison of Taffel analysis and electrochemical impedance spectroscopy (EIS). Also, a new nanocomposite including polydopamine (PDA) and zeolite imidazole frame work composed from Zn (NO3)2 .6H2O and 2-methylimidazole (ZIF-8) that name PDA@ZIF-8 has been used as biocompatible and corrosion resistance amplifier to the precursor solution and used in the multilayer deposition process. The morphology analysis including atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM) imaging and the obtained parameters show that coating has appropriate roughness that could increase the bounding of implant. A good adhesion strength has been determined for the two-layers silane coating with PDA@ZIF-8 according to the pull- off test. On the other hand, the antibacterial analysis indicate that the coating is an effective material for S. mutans and E. coli reduction that is another criterion for the dental implant materials. The results was introduced the coated Ti-6Al-4V could be used as corrosion resistive and antibacterial dental implant material.