Ruijing Liang

Shaping Functional Nano‐objects by 3D Confined Supramolecular Assembly

Nano-objects are generated through 3D confined supramolecular assembly, followed by a sequential disintegration by rupturing the hydrogen bonding. The shape of the nano-objects is tunable, ranging from nano-disc, nano-cup, to nano-toroid. The nano-objects are pH-responsive. Functional materials for example inorganic or metal nanoparticles are easily complexed onto the external surface, to extend both composition and microstructure of the nano-objects.

Multiresponsive Hydrogel Photonic Crystal Microparticles with Inverse-Opal Structure

Hydrogel photonic crystal microparticles (HPCMs) with inverse-opal structure are generated through a combination of microfluidic and templating technique. Temperature and pH responsive HPCMs have firstly been prepared by copolymerizing functional monomers, for example, N-isopropylacrylamide (NIPAm) and methacrylic acid (MAA). HPCMs not only show tunable color variation almost covering the entire wavelength of visible light (above 150 nm of stop-band shift) by simply tailoring temperature or pH value of the solution, but also display rapid response (less than 1 min) due to the small volume and well-ordered porous structure. Importantly, the temperature sensing window of the HPCMs can be enlarged by controlling the transition temperature of the hydrogel matrix, and the HPCMs also exhibit good reversibility and reproducibility for pH response. Moreover, functional species or particles (such as azobenzene derivative or magnetic nanoparticles) can be further introduced into the hydrogel matrix by using post-treatment process. These functionalized HPCMs can respond to the UV/visible light without significantly influencing the temperature and pH response, and thus, multiresponsive capability within one single particle can be realized. The presence of magnetic nanoparticles may facilitate secondary assembly, which has potential applications in advanced optical devices.

Biodegradable Polymer Microcapsules Fabrication through a Template-Free Approach

A detailed study on the direct synthesis of biocompatible polyesters (e.g., PLA, PLGA or PCL) microcapsules and multifunctional microcapsules, which does not require any template and core removal, is presented. The technique is based on the modified self-emulsification process within the emulsion droplets by simply adding sodium dioctyl sulfosuccinate (Aerosol OT or AOT) as a cosurfactant to the initial polymer solution, followed by double emulsion formation due to the coalescence of the internal water droplets. Microcapsules with tunable sizes (ranging from hundreds of nanometers to tens of micrometers) and morphologies were then obtained through solidification of droplet shell of the double emulsion via solvent removal. In this report, we have systematically investigated the effect of experimental parameters, such as polymer and AOT concentration, polymer molecular weight on the double emulsion formation process, and the final morphologies of the microcapsules. We demonstrate that the capsules can encapsulate either hydrophobic or hydrophilic dyes during solvent evaporation. Dye-release studies show a correlation between shell thickness, capsules size, and diffusive release rate, providing insights into the shell formation and shell thickness processing. Moreover, hydrophobic nanoparticles, such as oleic-acid coated Fe(3)O(4) nanoparticles and quantum dots, can also be incorporated into the walls of the microcapsules. Such functional microcapsules might find applications in the fields of controlled release, bioimaging, diagnostics, and targeting.

Recent advances in targeted nanoparticles drug delivery to melanoma

Melanoma is one of the most aggressive skin cancers, notorious for its high multidrug resistance and low survival rate. Conventional therapies (e.g., dacarbazine, interferon-alpha-2b and interleukin-2) are limited by low response rate and demonstrate no overall survival benefit. Novel targeted therapies (e.g., vemurafenib, dabrafenib and trametinib) have higher initial response rate and clear impact on the overall survival, but relapse usually occurs within 6 to 9 months. Although immunotherapy (e.g., ipilimumab, pembrolizumab and nivolumab) can achieve long-term and durable response, rate of adverse events is extremely high. With the development of nanotechnology, the applications of nanocarriers are widely expected to change the landscape of melanoma therapy for foreseeable future. In this review, we will relate recent advances in the application of multifunctional nanocarriers for targeted drug delivery to melanoma, in melanoma nanotheranostics and combination therapy, and nanopharmaceutical associated melanoma clinical trials, followed by challenges and perspectives. From the clinical editor: The team of authors describes the current treatment regimes of malignant melanoma emphasizing the importance of achieving a better efficacy and the need to develop a better understanding of melanoma tumorigenesis.

Electric-Field-Assisted Assembly of Polymer-Tethered Gold Nanorods in Cylindrical Nanopores.

In this report, we demonstrate the confined assembly of polymer-tethered gold nanorods in anodic aluminum oxide (AAO) channels with the assistance of electric field (EF). Various interesting hybrid assemblies, such as single-, double-, triple-, or quadruple-helix, linear, and hexagonally packed structures are obtained by adjusting pore size in AAO channels, ligand length, and EF orientation. Correspondingly, surface plasmonic property of the assemblies can thus be tuned. This strategy, by coupling of external-field and cylindrically confined assembly, is believed to be a promising approach for generating ordered hybrid assemblies with hierarchical structures, which may find potential applications in photoelectric devices, biosensors, and data storage devices.

Multifunctional biodegradable polymer nanoparticles with uniform sizes: generation and in vitro anti-melanoma activity.

We present a simple, yet versatile strategy for the fabrication of uniform biodegradable polymer nanoparticles (NPs) with controllable sizes by a hand-driven membrane-extrusion emulsification approach. The size and size distribution of the NPs can be easily tuned by varying the experimental parameters, including initial polymer concentration, surfactant concentration, number of extrusion passes, membrane pore size, and polymer molecular weight. Moreover, hydrophobic drugs (e.g., paclitaxel (PTX)) and inorganic NPs (e.g., quantum dots (QDs) and magnetic NPs (MNPs)) can be effectively and simultaneously encapsulated into the polymer NPs to form the multifunctional hybrid NPs through this facile route. These PTX-loaded NPs exhibit high encapsulation efficiency and drug loading density as well as excellent drug sustained release performance. As a proof of concept, the A875 cell (melanoma cell line) experiment in vitro, including cellular uptake analysis by fluorescence microscope, cytotoxicity analysis of NPs, and magnetic resonance imaging (MRI) studies, indicates that the PTX-loaded hybrid NPs produced by this technique could be potentially applied as a multifunctional delivery system for drug delivery, bio-imaging, and tumor therapy, including malignant melanoma therapy.

Structural Transformation of Diblock Copolymer/Homopolymer Assemblies by Tuning Cylindrical Confinement and Interfacial Interactions.

In this study, we report the controllable structural transformation of block copolymer/homopolymer binary blends in cylindrical nanopores. Polystyrene-b-poly(4-vinylpyridine)/homopolystyrene (SVP/hPS) nanorods (NRs) can be fabricated by pouring the polymers into an anodic aluminum oxide (AAO) channel and isolated by selective removal of the AAO membrane. In this two-dimensional (2D) confinement, SVP self-assembles into NRs with concentric lamellar structure, and the internal structure can be tailored with the addition of hPS. We show that the weight fraction and molecular weight of hPS and the diameter of the channels can significantly affect the internal structure of the NRs. Moreover, mesoporous materials with tunable pore shape, size, and packing style can be prepared by selective solvent swelling of the structured NRs. In addition, these NRs can transform into spherical structures through solvent-absorption annealing, triggering the conversion from 2D to 3D confinement. More importantly, the transformation dynamics can be tuned by varying the preference property of surfactant to the polymers. It is proven that the shape and internal structure of the polymer particles are dominated by the interfacial interactions governed by the surfactants.

Block Copolymer Capsules with Structure‐Dependent Release Behavior

Although high-boiling non-solvent induced macrophase separation in emulsion droplets has been widely applied for the fabrication of polymeric capsules, precise control of their structures remains a great challenge. Herein, block copolymer capsules with tunable shell structures were fabricated by employing a non-solvent as a liquid template in emulsion droplets. The properties of the non-solvents dictate the phase separation sequence in the droplets and the capsule formation mechanism. Two different pathways for capsule formation were observed, and could be applied to predict the shell structure. The structured capsules could be transformed into mesoporous capsules, which demonstrated an intriguing structure-dependent release behavior. Capsules with spherical shell structures displayed the best permeability, while those with lamellar shell structures showed the slowest release, but with a stepwise profile. After loading with an anticancer drug, different capsules induced different apoptosis ratios in cancer cell studies.

Encapsulation of pristine fullerene C60 within block copolymer micelles through interfacial instabilities of emulsion droplets

We report a facile and versatile strategy to encapsulate pristine fullerene (C60) within spherical or wormlike block copolymer micelles through interfacial instability of emulsion droplets. C60 and amphiphilic block copolymer polystyrene-b-poly(ethylene oxide) were firstly dispersed in chloroform. The resulting solution was emulsified with aqueous sodium dodecylsulfate solution by simply shaking it. The emulsion droplets were collected in an open container and the solvent was allowed to evaporate. During solvent evaporation, the emulsion droplets became unstable and broke into tiny droplets, i.e., interfacial instabilities occurred, triggering the formation of uniform spherical micelles with encapsulated fullerenes in the micellar cores. More interestingly, fullerene addition induced a morphological transition from cylindrical micelles to string-of-vesicles and then to spherical micelles with increasing fullerene contents of 5 wt%, 10 wt%, and 30 wt%, respectively. We show that the optical properties of the confined C60 molecules can be modified by varying the quantity of fullerenes in the micelles. In addition, poly(3-hexylthiophene) (P3HT) can be co-encapsulated with C60 into the micellar cores when P3HT was dissolved in the initial polymer solution prior to emulsification. Presence of C60 in the micellar cores induced fluorescence quenching of P3HT due to photoinduced energy transfer from electron-donating P3HT to electron-accepting C60 molecules. Hybrid micelles with well-controlled structures and components can be potentially useful in the area of photodynamic therapy and photovoltaics.

Uniform Core–Shell Photonic Crystal Microbeads as Microcarriers for Optical Encoding

We demonstrate a rapid and robust method to fabricate uniform core-shell photonic crystal (PC) microbeads by the microfluidic and centrifugation-redispersion technique. Colored crystalline colloidal arrays (CCAs) were first prepared through centrifugation-redispersion approach by self-assembly of polystyrene-poly(N-isopropylacrylamide) (PS-PNIPAm) core/shell nanoparticles (NPs). Different from the conventional NPs (e.g., charged PS or PNIPAm NPs), PS-PNIPAm NPs could easily self-assemble into well-ordered CCAs by only one purification step without laborious pretreatment (e.g., dialysis or ion exchange) or slow solvent-evaporation process. The CCAs is then encapsulated into a transparent polymer shell with functional groups (e.g., copolymer of ETPTA and butyl acrylate (BA)), triggering the formation of core-shell PC microbeads which can be used as optical encoding microcarriers. Importantly, this technique allows us to produce core-shell PC microbeads in a rapid and robust way, and the optical reflections of the PC microbeads appear highly stable to various external stimuli (e.g., temperature, pH value, and ionic strength) relying on the features of the CCAs core and protection of the polymer shell. Moreover, various probe biomolecules (e.g., proteins, antibodies, and so on) can be easily linked on the surface of the core-shell PC microbeads owing to the hydrophilic modification induced by the hydrolysis of BA on the microbead surface, enabling the multiplex biomolecular detection.