Size control of polydopamine nodules formed on polystyrene particles during dopamine polymerization with carboxylic acid-containing compounds for the fabrication of raspberry-like particles

Tailoring and application of a multi-responsive cellulose nanofibre-based 3D nanonetwork wound dressing

The rapid loss of drugs and the weak curative effects due to cyclical urination are the main reasons why wound heal with difficulty after bladder tumour resection. Here, a bioinspired cellulose nanofibre (CNF)-based magnetic 3D nanonetwork wound dressing with excellent tissue adhesion and biocompatibility is designed by the assembly of pH- and near infrared-responsive CNF nanoskeletons, magnetic switching Fe₃O₄ nanoparticles, and temperature switching Pluronic®F-127. The dressing with high loading capacity for mitomycin and indocyanine green can form a sticky 3D nanonetwork at the wound site and remain for a long time to release drugs through an external magnetic field. Interestingly, the dressing possessed excellent antibacterial activity, bacterial biofilm elimination, T24 tumour cell killing, and wound healing promotion through photothermal, photodynamic, and chemotherapy. Therefore, it has promising application for bladder postoperative infected wound healing to avoid rapid loss of drugs due to cyclical urination.

Preparation of Structural Color on Cotton Fabric with High Color Fastness through Multiple Hydrogen Bonds between Polyphenol Hydroxyl and Lactam

Structural coloration is an important way to realize eco-friendly dyeing of textiles. Structural colored cotton fabric was obtained by fabricating a polydopamine (PDA) film on the white cotton fabric at different polymerization reaction times. PDA is prone to generate capillary tension during film formation, which damages the uniformity and interfacial bonding force of the film. Multiple hydrogen bonds will form between the lactam group of polyvinylpyrrolidone (PVP) and the phenolic hydroxyl group of PDA. The introduced hydrogen bonds will effectively enhance the interfacial bond strength and lead to structural color with high color fastness. The surface morphology of double-layer aggregates of the PDA film on structural colored cotton fabric was revealed by scanning electron microscopy. The chemical constitution of the PDA film and PVP was investigated by Fourier transform infrared spectroscopy and X-ray diffraction. The color characteristics of structural colored cotton fabrics were analyzed by UV-vis reflectance spectroscopy and spectrophotometry.

A bionic cellulose nanofiber-based nanocage wound dressing for NIR-triggered multiple synergistic therapy of tumors and infected wounds

Tumor recurrence and drug-resistant bacterial infection are the main reasons that wounds heal with difficulty after skin tumor treatment. The near infrared- (NIR-) and pH-responsive, bionic, cellulose nanofiber-based (CNF-based) nanocage wound dressing with biocompatibility, bioviscosity, and shape adaptability is designed for dual NIR-triggered photothermal therapy of tumor and infection-induced wound healing. The wound dressing with the intertwining three dimensional (3D) nanocage network structure is skillfully constructed using NIR-responsive cellulose nanofibers and pH-responsive cellulose nanofibers as the skeleton, which endows the dressing with a high drug-loading capacity of doxorubicin (400 mg·g^-1), and indocyanine green (25 mg·g^-1). Moreover, the NIR- and pH-responsive bionic "On/Off" switches of the dressing enable a controllable and efficient drug release onto the wound area. The dual NIR-triggered wound dressing with excellent photothermal conversion performance possesses good antibacterial properties against Escherichia coli, Staphylococcus aureus, and drug-resistant Staphylococcus aureus. It could effectively eliminate bacterial biofilms and kill A375 tumor cells. Interestingly, the bionic wound dressing with shape adaptability could adapt and treat irregular postoperative skin tumor wounds and drug-resistant bacterial infection via the synergistic therapy of photothermal, photodynamic, and chemotherapy, which provides an ideal strategy for clinical intervention.

Recent advances in dopamine-based materials constructed via one-pot co-assembly strategy

Dopamine-based materials have attracted widespread interest due to the outstanding physicochemical and biological properties. Since the first report on polydopamine (PDA) films, great efforts have been devoted to develop new fabrication strategies for obtaining novel nanostructures and desirable properties. Among them, one-pot co-assembly strategy offers a unique pathway for integrating multiple properties and functions into dopamine-based platform in a single simultaneous co-deposition step. This review focuses on the state of the art development of one-pot multicomponent self-assembly of dopamine-based materials and summarizes various single-step co-deposition approaches, including PDA-assisted adaptive encapsulation, co-assembly of dopamine with other molecules through non-covalent interactions or covalent interactions. Moreover, emerging applications of dopamine-based materials in the fields ranging from sensing, cancer therapy, catalysis, oil/water separation to antifouling are outlined. In addition, some critical remaining challenges and opportunities are discussed to pave the way towards the rational design and applications of dopamine-based materials.

Recent Advances in Antioxidant Polymers: From Sustainable and Natural Monomers to Synthesis and Applications

Advances in technology have led to the production of sustainable antioxidants and natural monomers for food packaging and targeted drug delivery applications. Of particular importance is the synthesis of lignin polymers, and graft polymers, dopamine, and polydopamine, inulin, quercetin, limonene, and vitamins, due to their free radical scavenging ability, chemical potency, ideal functional groups for polymerization, abundance in the natural environment, ease of production, and activation of biological mechanisms such as the inhibition of the cellular activation of various signaling pathways, including NF-κB and MAPK. The radical oxygen species are responsible for oxidative damage and increased susceptibility to cancer, cardiovascular, degenerative musculoskeletal, and neurodegenerative conditions and diabetes; such biological mechanisms are inhibited by both synthetic and naturally occurring antioxidants. The orientation of macromolecules in the presence of the plasticizing agent increases the suitability of quercetin in food packaging, while the commercial viability of terpenes in the replacement of existing non-renewable polymers is reinforced by the recyclability of the precursors (thyme, cannabis, and lemon, orange, mandarin) and marginal ecological effect and antioxidant properties. Emerging antioxidant nanoparticle polymers have a broad range of applications in tumor-targeted drug delivery, food fortification, biodegradation of synthetic polymers, and antimicrobial treatment and corrosion inhibition. The aim of the review is to present state-of-the-art polymers with intrinsic antioxidant properties, including synthesis scavenging activity, potential applications, and future directions. This review is distinct from other works given that it integrates different advances in antioxidant polymer synthesis and applications such as inulin, quercetin polymers, their conjugates, antioxidant-graft-polysaccharides, and polymerization vitamins and essential oils. One of the most comprehensive reviews of antioxidant polymers was published by Cirillo and Iemma in 2012. Since then, significant progress has been made in improving the synthesis, techniques, properties, and applications. The review builds upon existing research by presenting new findings that were excluded from previous reviews.

Smaller Is Not Always Better: Large-Size Hollow Polydopamine Particles Act as an Efficient Sun Protection Factor Booster for Sunscreens

Ultraviolet (UV) radiation from the sun is the most harmful factor for human skin, causing sunburn, melasma, freckles, blemishes, and skin cancer. Sunscreens play a key role in blocking UV absorption on the skin. This study focused on the synthesis of hollow polydopamine (h-PDA), whose structure mimics the naturally occurring melanin in humans, for use as an active ingredient in sunscreens by means of a hard-template-based method. The reactions involve a spontaneous polymerization of a dopamine monomer in the presence of tris(hydroxymethyl)aminomethane (Tris) as a catalyst onto a polystyrene (PS) core template. Different sizes of the PS core (about 280 and 450 nm) and weight ratios of PS/DA were applied to elucidate the effect of the hollow diameter and thickness of the shell on the morphology and absorbance of the synthesized h-PDA. From UV absorption results, it was observed that the synthesized h-PDA particles with a larger core diameter (about 450 nm) and a thin shell thickness (about 57 nm) presented high UV absorption. We found that the structure of the synthesized h-PDA is mainly composed of a mixture of 5,6-dihydroxyindole and indole-5,6-quinone precursors covalently linked together. After blending the h-PDA particles with the base cream, the formulation containing h-PDA with a large void diameter of about 450 nm showed the highest sun protection factor (SPF) of up to 7.43, which is related to % booster of 234.7%. In addition, the h-PDA particles exhibited biocompatibility and cellular uptake in keratinocyte HaCaT cells after 24 h of incubation, indicating the potential to mimic natural melanin in preventing UV-induced DNA damage, which could be safely used as an alternative sunscreen.

Progress in polydopamine-based melanin mimetic materials for structural color generation

Structural color is a color derived from optical interaction between light and a microstructure and is often seen in nature. Natural melanin plays an important role in bright structural coloration. For example, the vivid colors of peacock feathers are due to structural colors. The periodic arrangement of melanin granules inside the feathers leads to light interference, and the black granules absorb scattered light well, resulting in bright structural color. In recent years, polydopamine (PDA) has attracted attention as a melanin mimetic material. This review article summarizes recent research on structural coloration using PDA-based artificial melanin materials. It also outlines possible applications using bright structural colors realized by artificial melanin materials and future perspectives.

Multimodal Mesoporous Silica Nanocarriers for Dual Stimuli-Responsive Drug Release and Excellent Photothermal Ablation of Cancer Cells

Background

Core-shell types of mesoporous silica nanoparticles (MSNs) with multimodal functionalities were developed for bio-imaging, controlled drug release associated with external pH, and near-infrared radiation (NIR) stimuli, and targeted and effective chemo-photothermal therapeutics.

Materials and Methods

We synthesized and developed a core-shell type of mesoporous silica nanocarriers for fluorescent imaging, stimuli-responsive drug release, magnetic separation, antibody targeting, and chemo-photothermal therapeutics. Also, the biocompatibility, cellular uptake, cytotoxicity, and photothermal therapy on these FS3-based nanocarriers were systematically investigated.

Results

Magnetic mesoporous silica nanoparticles was prepared by coating a Fe₃O₄ core with a mesoporous silica shell, followed by grafting with fluorescent conjugates, so-called FS3. The resulting FM3 was preloaded with therapeutic cisplatin and coated with polydopamine layer, so-called FS3P/C. Eventually, graphene oxide-wrapped FS3P/C (FS3P-G/C) exhibited high sensitivity in the dual stimuli (pH, NIR)-responsive controlled release behavior. On the other hand, Au NPs-coated FS3P/C (FS3P-A/C) exhibited more stable release behavior, irrespective of pH changes, and exhibited much more enhanced release rate under the same NIR irradiation. Notably, FS3P-A/C showed strong NIR absorption, enabling photothermal destruction of HeLa cells by its chemo-photothermal therapeutic effects under NIR irradiation (808 nm, 1.5 W/cm²). The selective uptake of FS3-based nanocarriers was confirmed in cancer cell lines including HeLa (American Type Culture Collection - ATCC) and SHSY5Y (ATCC 2266) by the images obtained from confocal laser scanning microscopy, flow cytometry, and transmission electron microscopy instruments. Cisplatin-free FS3-based nanocarriers revealed good cellular uptake and low cytotoxicity against cancerous HeLa and SH-SY5Y cells, but showed no obvious toxicity to normal HEK293 (ATCC 1573) cell.

Conclusion

Along with the facile synthesis of FS3-based nanocarriers, the integration of all these strategies into one single unit will be a prospective candidate for biomedical applications, especially in chemo-photothermal therapeutics, targeted delivery, and stimuli-responsive controlled drug release against multiple cancer cell types.

A highly colorimetric photonic film composed of non-close-packed melanin-like colloidal arrays

HOTHESIS

Because of their flexible structure and adjustable color, structural colors with non-close-packed colloidal crystal arrays (NCCAs) have broad applications. However, most of these structural colors are limited by an approximate refractive index or high background scattering, and they present an unsatisfactory color that seriously hinders their practical application. Preparation of particles with a high refractive index or adsorption coefficient may be an effective approach to construct highly colorimetric NCCA structural colors in a nonaqueous solvent. The aim of this study was to explore the formation process of NCCA by the assembly of colloidal particles in a nonaqueous solvent, so as to fabricate NCCAs with a high refractive index and high adsorption.

EXPERIMENTS

An attempt was made to fabricate the NCCA structural color by dispersing the desired particles in a 2-hydroxyethyl methacrylate (HEMA) solvent. Surface-functionalized poly(methyl methacrylate) (PMMA) particles were developed by emulsifier-free emulsion polymerization. The formation of NCCA was studied by comparing the dispersion of three classes of surface-functionalization of colloidal particles in the HEMA solvent. The melanin-like particles with a high refractive index and a high adsorption coefficient were synthesized by doping polydopamine (PDA) into good surface-functionalization particles by emulsifier-free emulsion polymerization. A highly colorimetric poly(2-hydroxyethyl methacrylate) (pHEMA) optical film with NCCA was fabricated by dispersing the melanin-like particles in a pHEMA hydrogel.

FINDINGS

PMMA-HEMA colloidal particles could successfully construct a NCCA structure in a nonaqueous HEMA solvent because of the solvation. Based on the "good particles," PMMA-HEMA-PDA colloidal particles, an initial 3-hydroxytyramine hydrochloride (DA·HCl) concentration of 1.926 mM was shown to significantly improve the colorimetric value of the final solidified NCCA hydrogel. These results provided an important reference for the construction of surfactant-free HEMA non-close-packed colloidal crystals. This highly colorimetric structurally colored hydrogel may be widely used in the design of a variety of colored intelligent sensors and soft devices.

Synthetic strategies for raspberry-like polymer composite particles

The strategies used for the preparation of raspberry-like polymer composite particles are summarized comprehensively.

Development, Validation, and Performance of Chitosan-Based Coatings Using Catechol Coupling

The use of long-lasting polymer coatings on biodevice surfaces has been investigated to improve material-tissue interaction, minimize adverse effects, and enhance their functionality. Natural polymers, especially chitosan, are of particular interest due to their excellent biological properties, such as biocompatibility, non-toxicity, and antimicrobial properties. One way to produce chitosan coating is by covalent grafting with catechol molecules such as dopamine, caffeic acid, and tannic acid, resulting in an attachment ten times stronger than that of simple physisorption. Caffeic acid presents an advantage over dopamine because it allows direct chitosan grafting, due to its terminal carboxylic acid group, without the need of a linking arm, as employed in the dopamine approach. In this study, the grafting of chitosan using caffeic acid, over surfaces or in solution, is compared with dopamine grafting using poly(ethylene glycol) as a linking arm. The following coating properties are observed; covering and homogeneity are assessed by X-ray photoelectron spectroscopy and atomic force microscopy analyses, hydrophilicity with contact angle measurements, stability with aging tests, anticorrosion behavior, and coating non-toxicity. Results show that grafting using caffeic acid/chitosan in solution over a metallic surface may be advantageous, compared to traditional dopamine coating.

Using γ-Ray Polymerization-Induced Assemblies to Synthesize Polydopamine Nanocapsules

This work reports a simple and robust strategy for synthesis of polydopamine nanocapsules (PDA NCs). First, polymer assemblies were synthesized by a γ-ray-induced liquid-liquid (H2O-acrylate) interface polymerization strategy, in the absence of any surfactants. 1H nuclear magnetic resonance analysis and molecular dynamics simulation reveal that the generation of polymer assemblies largely depends on the hydrophilicity of acrylate and gravity of the oligomers at the interface. By virtue of the spherical structure and mechanic stability of the polymer assemblies, PDA NCs are next prepared by the interfacial polymerization of dopamine onto the assemblies, followed by the removal of templates by using ethanol. The polydopamine nanocapsules are shown to load and release ciprofloxacin (CIP, a model drug), such that the CIP-loaded PDA NCs are able to inhibit the growth of Escherichia coli.

Versatile Polydopamine Platforms: Synthesis and Promising Applications for Surface Modification and Advanced Nanomedicine

As a mussel-inspired material, polydopamine (PDA), possesses many properties, such as a simple preparation process, good biocompatibility, strong adhesive property, easy functionalization, outstanding photothermal conversion efficiency, and strong quenching effect. PDA has attracted increasingly considerable attention because it provides a simple and versatile approach to functionalize material surfaces for obtaining a variety of multifunctional nanomaterials. In this review, recent significant research developments of PDA including its synthesis and polymerization mechanism, physicochemical properties, different nano/microstructures, and diverse applications are summarized and discussed. For the sections of its applications in surface modification and biomedicine, we mainly highlight the achievements in the past few years (2016-2019). The remaining challenges and future perspectives of PDA-based nanoplatforms are discussed rationally at the end. This timely and overall review should be desirable for a wide range of scientists and facilitate further development of surface coating methods and the production of PDA-based materials.

Melanin Precursor Influence on Structural Colors from Artificial Melanin Particles: PolyDOPA, Polydopamine, and Polynorepinephrine

Polydopamine (PDA) is of interest as a mimetic material of melanin to produce structural color materials. Herein, to investigate the influence of the material composition of the artificial melanin particles on structural color, we demonstrated the preparation of core-shell particles by polymerization of norepinephrine or 3,4-dihydroxyphenylalanine, which are melanin precursors similar to dopamine, in the presence of polystyrene particles. It was revealed that the arrays of the prepared particles produce high-visibility structural color because of absorption of scattering light. Although poly(3,4-dihydroxyphenylalanine) showed the same tendency as PDA which was previous studied, polynorepinephrine can easily produce a smooth and thick shell layer compared with that of PDA, and pellets consisting of the particles showed angle-dependent structural color. Therefore, the artificial melanin particles that produce angle-dependent structural color became stable than ever before. These results indicated that material compositions of artificial melanin particles have influence on structural color, and an important finding for application as a coloring material was obtained.

Investigation of different core-shell toward Janus morphologies by variation of surfactant and feeding composition: A study on the kinetics of DOX release

Composite particles with two individual hydrophilic parts were synthesized via seeded emulsion polymerization. As first part, nearly-monodisperse ethylene glycol dimethacrylate (EGDMA)-crosslinked poly(acrylic acid) (PAA) particles were synthesized by distillation precipitation polymerization (DPP). These particles were used as seeds in emulsion polymerization of 2-(dimethylamino)ethyl methacrylate (DMAEMA). Effects of type of surfactant, monomers/seed weight ratio and amount of shell crosslinker on the synthesized composite particles' morphology were studied. Different morphologies consisting of core-shell, Janus type, raspberry-like and porous core-shell structures were investigated by variations of polymerization parameters. Different structures were chosen as drug carriers and subjected to DOX loading and release system. Results showed that amount of drug loading and extent of release were strongly dependent on the structure of carriers whereas for all carriers, DOX was released more rapid. Kinetics of release was evaluated by different mathematical models to investigate the release mechanism through composite particles. Results showed that only Korsmeyer-Peppas model fitted the drug release data and other ones were inappropriate in this field.

Polydopamine-Based 3D Colloidal Photonic Materials: Structural Color Balls and Fibers from Melanin-Like Particles with Polydopamine Shell Layers

Nature creates beautiful structural colors, and some of these colors are produced by nanostructural arrays of melanin. Polydopamine (PDA), an artificial black polymer produced by self-oxidative polymerization of dopamine, has attracted extensive attention because of its unique properties. PDA is a melanin-like material, and recent studies have reported that photonic materials based on PDA particles showed structural colors by enhancing color saturation through the absorption of scattered light. Herein, we describe the preparation of three-dimensional (3D) colloidal photonic materials, such as structural color balls and fibers, from biomimetic core-shell particles with melanin-like PDA shell layers. Structural color balls were prepared through the combined use of membrane emulsion and heating. We also demonstrated the use of microfluidic emulsification and solvent diffusion for the fabrication of structural color fibers. The obtained 3D colloidal materials, i.e., balls and fibers, exhibited angle-independent structural colors due to the amorphous assembly of PDA-containing particles. These findings provide new insight for the development of dye-free technology for the coloration of various 3D colloidal architectures.

Determination of fermentable sugars in beer wort by gold nanoparticles@polydopamine: A layer-by-layer approach for Localized Surface Plasmon Resonance measurements at fixed wavelength

Polydopamine decorated in-situ with Localized Surface Plasmon Resonance (LSPR)-active gold nanoparticles (AuNPs) may extend the applicability of nanoplasmonic materials to original and innovative applications in several fields. Here we report the modification of disposable UV-Vis polystyrene cuvettes with AuNPs@PDA for refractive index LSPR-based measurements. An original layer-by-layer deposition method of PDA followed by AuNPs growth is here developed, showing linear correlation between PDA thickness and optical properties. In particular, the modulation from wavelength sensitivity toward absorbance sensitivity is obtained, allowing measurements at fixed wavelength (578 nm). As applicative example of the photonic cuvettes, the measurement of fermentable sugars in beer wort is here reported. The analytical performance of our approach has been directly compared to portable refractometer of reference, displaying excellent results in terms of the precise estimation of sugars in beer wort (expressed in degrees Brix), reproducibility and sensitivity. The approach may be extended to other materials of interest in LSPR based optical sensors, e.g. optical fibers.

Recent developments in dopamine-based materials for cancer diagnosis and therapy

Dopamine-based materials are emerging as novel biomaterials and have attracted considerable interests in the fields of biosensing, bioimaging and cancer therapy due to their unique physicochemical properties, such as versatile adhesion property, high chemical reactivity, excellent biocompatibility and biodegradability, strong photothermal conversion capacity, etc. In this review, we present an overview of recent research progress on dopamine-based materials for diagnosis and therapy of cancer. The review starts with a summary of the physicochemical properties of dopamine-based materials in general. Then detailed description is followed on their applications in the fields of diagnosis and treatment of cancers. The review concludes with an outline of some remaining challenges for dopamine-based materials to be used for clinical applications.

Structural Color Tuning: Mixing Melanin-Like Particles with Different Diameters to Create Neutral Colors

We present the ability to tune structural colors by mixing colloidal particles. To produce high-visibility structural colors, melanin-like core-shell particles composed of a polystyrene (PSt) core and a polydopamine (PDA) shell, were used as components. The results indicated that neutral structural colors could be successfully obtained by simply mixing two differently sized melanin-like PSt@PDA core-shell particles. In addition, the arrangements of the particles, which were important factors when forming structural colors, were investigated by mathematical processing using a 2D Fourier transform technique and Voronoi diagrams. These findings provide new insights for the development of structural color-based ink applications.

Sulfonated chitosan and dopamine based coatings for metallic implants in contact with blood

Thrombosis and calcification constitute the main clinical problems when blood-interacting devices are implanted in the body. Coatings with thin polymer layers represent an acknowledged strategy to modulate interactions between the material surface and the blood environment. To ensure the implant success, at short-term the coating should limit platelets adhesion and delay the clot formation, and at long-term it should delay the calcification process. Sulfonated chitosan, if compared to native chitosan, shows the unique ability to reduce proteins adsorption, decrease thrombogenic properties and limit calcification. In this work, stainless steel surfaces, commonly used for cardiovascular applications, were coated with sulfonated chitosan, by using dopamine and PEG as anchors, and the effect of these grafted surfaces on platelet adhesion, clot formation as well as on calcification were investigated. Surface characterization techniques evidenced that the coating formation was successful, and the sulfonated chitosan grafted sample exhibited a higher roughness and hydrophilicity, if compared to native chitosan one. Moreover, sulfonated surface limited platelet activation and the process of clot formation, thus confirming its high biological performances in blood. Calcium deposits were also lower on the sulfonated chitosan sample compared to the chitosan one, thus showing that calcification was minimal in presence of sulfonate groups. In conclusion, this sulfonated-modified surface has potential to be as blood-interacting material.

Full-Color Biomimetic Photonic Materials with Iridescent and Non-Iridescent Structural Colors

The beautiful structural colors in bird feathers are some of the brightest colors in nature, and some of these colors are created by arrays of melanin granules that act as both structural colors and scattering absorbers. Inspired by the color of bird feathers, high-visibility structural colors have been created by altering four variables: size, blackness, refractive index, and arrangement of the nano-elements. To control these four variables, we developed a facile method for the preparation of biomimetic core-shell particles with melanin-like polydopamine (PDA) shell layers. The size of the core-shell particles was controlled by adjusting the core polystyrene (PSt) particles’ diameter and the PDA shell thicknesses. The blackness and refractive index of the colloidal particles could be adjusted by controlling the thickness of the PDA shell. The arrangement of the particles was controlled by adjusting the surface roughness of the core-shell particles. This method enabled the production of both iridescent and non-iridescent structural colors from only one component. This simple and novel process of using core-shell particles containing PDA shell layers can be used in basic research on structural colors in nature and their practical applications.

Polydopamine Particle as a Particulate Emulsifier

"Pickering-type" emulsions were prepared using polydopamine (PDA) particles as a particulate emulsifier and n-dodecane, methyl myristate, toluene or dichloromethane as an oil phase. All the emulsions prepared were oil-in-water type and an increase of PDA particle concentration decreased oil droplet diameter. The PDA particles adsorbed to oil⁻water interface can be crosslinked using poly(ethylene imine) as a crosslinker, and the PDA particle-based colloidosomes were successfully fabricated. Scanning electron microscopy studies of the colloidosomes after removal of inner oil phase revealed a capsule morphology, which is strong evidence for the attachment of PDA particles at the oil⁻water interface thereby stabilizing the emulsion. The colloidosomes after removal of inner oil phase could retain their capsule morphology, even after sonication. On the other hand, the residues obtained after oil phase removal from the PDA particle-stabilized emulsion prepared in the absence of any crosslinker were broken into small fragments of PDA particle flocs after sonication.

A facile strategy to fabricate covalently linked raspberry-like nanocomposites with pH and thermo tunable structures

A simple and controllable route to prepare covalently bonded raspberry-like composite particles with pH and thermal dual-responsiveness.