Polydopamine Nanostructures Research Articles

Integrating a Metal–Organic Framework into Natural Spruce Wood for Efficient Solar‐Powered Water Evaporation

With the increase in water consumption and pollution resulting from the rising world population and industrial development, severe fresh water shortage has been regarded as one of the critical problems facing the world. Solar‐driven water purification is an environment friendly and promising technology to address the problem. However, low photothermal conversion efficiency impedes its practical application. Herein, a natural spruce wood‐based solar evaporator functionalized with zeolitic imidazolate framework (ZIF‐8) nanoparticles and polydopamine (PDA) layers is designed, which significantly reduces the equivalent evaporation enthalpy and substantially boosts solar evaporation efficiency. The evaporation rate of the optimized wood‐based evaporator reached 2.28 kg m−2 h−1 with a high evaporation efficiency of 87.5% under 1.0 sun. Furthermore, the integrated spruce wood/ZIF‐8/PDA hybrids can remove organic pollutants after solar evaporation. Notably, the constructed multifunctional solar evaporator takes advantage of sustainable solar energy, low‐cost biomass, and ZIF‐8/PDA nanostructures to acquire desirable performance in water evaporation and sewage purification.

Insight into the role of polydopamine nanostructures on nickel foam-based photothermal materials for solar water evaporation

This study developed a solar evaporator by uniformly growing polydopamine nanowires (PDA NWs) on porous nickel foam (NF) substrate using a straightforward in situ approach. The synthesized material exhibited unique nanostructures, substantial hydrophilicity, and high porosity resulting in excellent light harvesting covering much of the solar spectrum. In addition, the utilized polystyrene foam support and cotton cloth resulted in a fast water supply to the evaporator along with heat localization. Good solar water evaporation rate of 1.39 kg m−2h−1, with a photothermal conversion efficiency of 87.8 % was achieved at one sun (1 kW m−2) illumination. The PDA NWs-NF evaporator displayed high-efficiency toward salt ions rejection and met the standard required for potable water. The synthesized material displayed good reusability and stability performance in real seawater and brine (75 g/L NaCl). The self-desalting capability of the prepared evaporator is driven via chemical advection and diffusion, resulting to fast salt dissolution. Our approach in fabricating cost-effective, scalable and environmentally friendly solar-thermal converter could meet the practical needs for solar-driven seawater desalination especially for remote communities.

Digital Numbers Constructed by Fine Patterned Polydopamine on DNA Templates.

Using DNA nanostructures as templates to synthesize shape-controlled polydopamine (PDA) is a promising strategy to realize the fabrication of exquisite PDA nanomaterials. However, previous studies using small DNA tiles as templates could only afford very simple structures such as lines and crosses due to the limited space on the template and the relatively low resolution of the PDA nanopatterns. Therefore, the best resolution of the PDA nanostructures that can be achieved by this technique is carefully investigated. And by connecting several DNA tiles together, larger DNA templates are built up and achieve the synthesis of complicated digital nanopatterned PDA structures.

Influence of PDA Coating on the Structural, Optical and Surface Properties of ZnO Nanostructures.

Polydopamine (PDA) is a new biocompatible material, which has prospects in biomedical and sensor applications. Due to functional groups, it can host wide range of biomolecules. ZnO nanostructures are well known templates for optical sensors and biosensors. The combination of ZnO and PDA results in a change of optical properties of ZnO–PDA composites as a shift of photoluminescence (PL) peaks and PL quenching. However, to date, the effect of the PDA layer on fundamental properties of ZnO–PDA nanostructures has not been studied. The presented paper reports on optical and surface properties of novel ZnO–PDA nanocomposites. PDA layers were chemically synthesized on ZnO nanostructures from different solution concentrations of 0.3, 0.4, 0.5 and 0.7 mg/mL. Structure, electronic and optical properties were studied by SEM, Raman, FTIR, diffuse reflectance and photoluminescence methods. The Z-potential of the samples was evaluated in neutral pH (pH = 7.2). The response of the samples towards poly-l-lysine adsorption, as a model molecule, was studied by PL spectroscopy to evaluate the correlation between optical and surface properties. The role of the PDA concentration on fundamental properties was discussed.

Mussel‐Inspired Dual‐Superlyophobic Biomass Membranes for Selective Oil/Water Separation

AbstractDual‐superlyophobic membranes that exhibit underwater superoleophobicity and underoil superhydrophobicity concurrently have gained considerable attention for oil/water separation. To effectively treat oily wastewater, consistent efforts have been made to develop fast and simple methodologies with low cost, environmentally friendly materials. Here, the dual‐superlyophobic membranes are obtained based on one‐step tailored growth of mussel‐inspired polydopamine (PDA) nanoparticles on the surfaces of biomass membranes. The results demonstrate that the universal adhesion of PDA allows the modification of biomass fibers of different surface hydrophobicity. The oxidation polymerization of dopamine leads to the rapid growth of PDA nanostructures, which form stable coatings of high roughness instead of homogeneous conformal coatings generated in the conventional synthesis of PDA. The amphiphilic nature of PDA and the rough surfaces imparted by the PDA nanostructures collectively lead to dual‐superlyophobic properties. Membranes of the coated biomass fibers prewetted by either water or oil become impermeable to the counterpart liquids, giving rise to efficient oil–water separation in a broad spectrum of mixtures. In particular, the membranes derived from cotton or kapok fibers show oil/water separation efficiencies of above 99.98%, fluxes ranging from 4000 to 22 200 L m−2 h−1, and robust performance for regeneration and repeated uses.

Chirally Twisted Ultrathin Polydopamine Nanoribbons: Synthesis and Spontaneous Assembly of Silver Nanoparticles on Them.

Polydopamine (PDA) is a synthetic polymeric material with immense potential in biomedical and surface functionalization applications. Herein, we have screened self-assemblies formed by Phenylalanine-based amphiphiles (Phe-AMPs) as soft templates for preparing chiral PDA nanostructures. Our study revealed that the amphiphile 2 endowed with a primary amine residue afforded chirally-twisted ultrathin nanoribbons of PDA under optimized conditions. The chirality at the Phe residue of 2 modulated the twist-chirality of the PDA nanoribbons; the l-2 resulted in nanoribbons with right-handed twist, whereas the d-2 induced a left-handed twist to the ribbons. The racemic mixture of these two amphiphiles produced flat, achiral tapes. The PDA ribbon thickness was ≈5.86±0.40 nm, whereas its width and length were ≈133.5±3.2 nm and >5000 nm, respectively. Upon dialysis, hollow PDA nanotubes were obtained due to curling of the PDA nanoribbons. These PDA-nanoarchitectures were employed to spontaneously form and assemble Ag-nanoparticles along the edges of the PDA nanoribbons. In this work we are reporting chirality controlled synthesis of PDA nanostructures for the first time.

Current Advances in the Utilization of Polydopamine Nanostructures in Biomedical Therapy.

Since the first time mussel-inspired polymer polydopamine (PDA) was discovered, it has gained enormous attention from numerous scientists, especially those working in the field of drug delivery and bacterial and tumor treatment, due to its distinctive properties, such as surface chemistry, biocompatibility, capability to adhere to any surface, and excellent photothermal conversion. Studies using PDA in various types of structures for therapeutic purposes have been carried out extensively in recent years. Considering the rapid development in the area, this review aims to cover and highlight the latest achievements (from 2016 to present) with respect to PDA-based materials for therapeutic purposes. A description of the diverse structures of PDA and its formation strategy, including colloidal particles, hollow structures, and coating films, are discussed. In addition, the main focus of this review is on the therapeutic applications of these PDA nanostructures.

Breaking Out the Traditional Polymerization: Tailoring the Shape, Structure, and Optical Properties of Polydopamine by Using CdTe Quantum Dots

AbstractThe potential applications of shape‐controlled polymeric nanostructures demand well‐defined methods to create tailored shapes. On the other hand, polydopamine (PDA) is a novel polymer promising a variety of innovative applications in many different areas. Since there is no consensus on the pathways involved in the mechanism of formation of PDA, the control of the final morphologies of PDA nanostructures is a challenging task. Herein, it is demonstrated for the first time, how CdTe quantum dots (CdTe QDs) can be used to control the final shape of polymeric structures, in particular, PDA particles. Oxidative self‐polymerization of dopamine is performed in the presence of CdTe QDs, which triggers the formation of blue‐colored rod‐like PDA particles. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV‐Vis, Fourier transform infrared (FT‐IR) and Raman spectroscopies, and electrochemical techniques are employed to characterize the structural features of the rod‐like PDA particles. Herein, CdTe QDs modulate the oxidative polymerization of dopamine by the supramolecular assembly of PDA building blocks by π–π and hydrogen bonding interactions, coordination with cadmium ions, and electron transfer processes. The results illustrated here describe a new strategy to manipulate the morphology of PDA nanostructures leading to novel optical properties, opening new applications, and shedding light on the complex mechanism of PDA formation.

Tailoring Biomolecular Interactions of Hybrid Nanostructures for their Diagnostic and Therapeutic Applications in Neurodegenerative Diseases

Alzheimer and Parkinson disease are common neurodegenerative disorders characterized by progressive structural and functional loss of the central nervous system. The foremost neuropathological events involve oxidative stress, mitochondrial dysfunction, inflammation and apoptosis. The disease-specific proteinopathies consists soluble aggregates including oligomers and protofibrils along with their phosphorylated variants deposited as plaque. The dynamic adsorption of these proteins on nanoparticle surface bestows with different physicochemical features and elicits the biological response. We show, in our approach molecular chemistry and optical characteristics of curcumin were used to elucidate the lanthanum carbonate nanospheres (REM100) and protein interactions via spontaneous binding of Aβ monomer and Aβ aggregates on Curcumin-REM100. The Protein concentration-dependent steady-state fluorescence enhancement of the curcumin and Langmuir protein adsorption model elucidates the maximum surface coverage and an apparent dissociation constant. Based on all experimental outcomes we demonstrated curcumin-REM100 as an efficient fluorescent probe able to delineate the monomer and the aggregate state of Amyloid-β with the Limit of detection (LOD) of 0.2 ±0.045 μM, the value is 30 times more sensitive than conventional Thioflavin-T (ThT) fluorescence emission intensity. The therapeutic approach uses the melatonin enriched polydopamine nanostructures for triggering robust neuroprotection against rotenone-induced neuroblastoma PD model. This causes reduction in cellular ROS level, re-establishing mitochondrial membrane potential, inhibiting caspase-dependent and independent apoptosis pathway and reducing alpha-synuclein phosphorylation at serine 129. The further in-vitro and organotypic mice brain slice culture-based therapeutic assessments have shown the superior neuroprotective potential of the developed nanoformulation. Considering the emerging interest in development of hybrid nanoformulation, our approaches elucidated diagnostic and therapeutic interventions in common neurodegenerative diseases.

Intensifying solar-thermal harvest of low-dimension biologic nanostructures for electric power and solar desalination

High-efficiency solar harvest and solar-thermal conversion have been targeted in modern sustainable energy science for diverse potential applications. However, broad applications with inorganic nanomaterials as solar-nanoheaters have suffered from low conversion efficiency, potential noxiousness and complicated synthesis procedures. Meanwhile, living organisms rely on delicate bio-synthesis of bio-macromolecules to produce organic bio-melanins with optimal nanostructures and solar-thermal properties for survival from harsh environments. Followed by this inspiration, alginate, one marine polysaccharide, is used to alter the polydopamine nanostructures, one artificial bio-melanin, from nanoparticles to high-aspect-ratio nanofibrils (diameter ~ 40 nm and aspect ratio up to 120 nm). During polymerization, alginate not only increases structural order (e.g. π-π conjugation) of polydopamine oligomers within their protoparticles, but also leads to linear consolidation of protoparticles. Polydopamine nanofibrils are found to exhibit super absorbance and high solar-thermal conversion efficiency (~ 86%) in full-range solar spectrum, being superior to conventional polydopamine nanoparticles and comparable to graphene and carbon nanotubes. Thus these biological nanofibrils may offer a promising platform for high-efficiency solar-energy harvest applicable in solar evaporative desalination, solar electric power etc.

Fabrication of Defined Polydopamine Nanostructures by DNA Origami‐Templated Polymerization

AbstractA versatile, bottom‐up approach allows the controlled fabrication of polydopamine (PD) nanostructures on DNA origami. PD is a biosynthetic polymer that has been investigated as an adhesive and promising surface coating material. However, the control of dopamine polymerization is challenged by the multistage‐mediated reaction mechanism and diverse chemical structures in PD. DNA origami decorated with multiple horseradish peroxidase‐mimicking DNAzyme motifs was used to control the shape and size of PD formation with nanometer resolution. These fabricated PD nanostructures can serve as “supramolecular glue” for controlling DNA origami conformations. Facile liberation of the PD nanostructures from the DNA origami templates has been achieved in acidic medium. This presented DNA origami‐controlled polymerization of a highly crosslinked polymer provides a unique access towards anisotropic PD architectures with distinct shapes that were retained even in the absence of the DNA origami template.

Fabrication of Defined Polydopamine Nanostructures by DNA Origami-Templated Polymerization.

A versatile, bottom‐up approach allows the controlled fabrication of polydopamine (PD) nanostructures on DNA origami. PD is a biosynthetic polymer that has been investigated as an adhesive and promising surface coating material. However, the control of dopamine polymerization is challenged by the multistage‐mediated reaction mechanism and diverse chemical structures in PD. DNA origami decorated with multiple horseradish peroxidase‐mimicking DNAzyme motifs was used to control the shape and size of PD formation with nanometer resolution. These fabricated PD nanostructures can serve as “supramolecular glue” for controlling DNA origami conformations. Facile liberation of the PD nanostructures from the DNA origami templates has been achieved in acidic medium. This presented DNA origami‐controlled polymerization of a highly crosslinked polymer provides a unique access towards anisotropic PD architectures with distinct shapes that were retained even in the absence of the DNA origami template.

Polydopamine Nanostructures as Biomaterials for Medical Applications.

Polydopamine is a versatile and organic material that can be deposited as a conformal film with nanometer thickness on virtually any substrate. Much of the initial foundational work regarding polydopamine synthesis and processing was reported during the 2000s. Latter years have witnessed increasing interest and widespread adoption of polydopamine as a material for many applications including medicine. Conformal polydopamine coatings confer unique chemical and physical properties to many substrate materials including metals, ceramics, polymers, and beyond. Polydopamine-modified surfaces permit facile bioconjugation of many biomedical materials for potential use as bioadhesives, contrast agents, drug delivery systems, and protein-adsorption resistant interfaces. Polydopamine-based materials and interfaces may improve the performance of biomedical devices used in neurotechnology, diagnostics, and cardiovascular applications. This highlight article reviews recent advances in polydopamine processing capabilities. The use of polydopamine as a material in various biomedical applications is also discussed. Finally, challenges and opportunites in translating polydopamine for future biomedical technologies are summarized.

Recent progress in the biomedical applications of polydopamine nanostructures.

Polydopamine is a dark brown-black insoluble biopolymer produced by autoxidation of dopamine. Although its structure and polymerization mechanism have not been fully understood, there has been a rapid growth in the synthesis and applications of polydopamine nanostructures in biomedical fields such as drug delivery, photothermal therapy, bone and tissue engineering, and cell adhesion and patterning, as well as antimicrobial applications. This article is dedicated to reviewing some of the recent polydopamine developments in these biomedical fields. Firstly, the polymerization mechanism is introduced with a discussion of the factors that influence the polymerization process. The discussion is followed by the introduction of various forms of polydopamine nanostructures and their recent applications in biomedical fields, especially in drug delivery. Finally, the review is summarized followed by brief comments on the future prospects of polydopamine.

Formation of polydopamine nanofibers with the aid of folic acid.

Polydopamine (PDA) generated by the oxidative self-polymerization of dopamine shows great potential for surface modification. Observed PDA nanostructures are nanoparticles and thin films. The formation mechanism of PDA is still unclear; thus, the manipulation of PDA nanostructures is a big challenge. In this study, we first demonstrated that folic acid shows a dramatic effect on the PDA nanostructure: New aggregated nanostructures of PDA, nanobelts and nanofibers, were generated in a dopamine/folic acid system. We hypothesized that folic acid may be involved in the stacking of protomolecules of PDA by π-π interactions and hydrogen bonding. Herein we describe the first experimental strategy to manipulate the aggregation of PDA by using small molecules. This study not only provides a new method for generating PDA nanofibers, which are proposed bioorganic electronic materials, but also a possible way to understand the formation mechanism of PDA and its analogues in nature, melanins.