Self-Assembly of Poly(Janus particle)s into Unimolecular and Oligomeric Spherical Micelles

A Triterpene-Based bioactive drug delivery system for combined chemotherapy of liver cancer

Carrier materials always account for the majority particularly in nanosized formulations, which are administrated along with the active ingredient part might result in metabolism related toxicity. The usage of bioactive excipients could not only reduce the sided effect but also provide additional therapeutic effects. In the present study, a triterpene based micellar drug delivery system was developed using a bioactive solanesol derivative. Solanesylamine was prepared firstly followed by conjugating with poly (ethylene glycol) using maleic acid amide linkage. The amphiphilic drug carrier PEGylated (2-propyl-3-methylmaleic acid)-block-solanesol amine (mPEG-CDM-NH-SOL) could be formed into micelles and loaded with doxorubicin (DOX) inside. The micelles were about 112 nm in size and the drug loading content was about 5.97 wt%. An acid triggered drug release behavior was obviously observed for the DOX loaded pH-sensitive micelle mPEG-CDM-NH-SOL-DOX. While not for DOX-loaded micelles without pH-sensitivity (mPEG-NHS-NH-SOL). CCK8 assay showed that the micelles of PEGylated solanesylamines exhibited certain inhibitory effect on tumor cells at high concentration and the pH sensitive ones seemed more toxic. In vivo studies showed that the pH sensitive mPEG-CDM-NH-SOL-DOX had a superior anti-tumor effect, indicating its great potential in cancer treatment.

Temperature-Sensitive Janus Particles PEG/SiO2/PNIPAM-PEA: Applications in Foam Stabilization and Defoaming

The current study presents a scalable approach for the preparation of temperature-responsive PEG/SiO2/PNIPAM-PEA Janus particles and, for the first time, investigates their potential applications in stabilizing foam and defoaming by adjusting the temperature. The method utilizes a (W1 + O)/W2 emulsion system, which incorporates appropriate surfactants to stabilize the emulsion and prevent rapid dissolution of the hydrophilic triblock polymer PEG-b-PTEPM-b-PNIPAM in water. The PEG/SiO2/PNIPAM-PEA Janus particles with temperature-responsive characteristics were synthesized in a single step that combined the sol-gel reaction and photoinduced free radical polymerization. The contact angle of the hydrophilic PEG/SiO2/PNIPAM surface was measured to be 54.7 ± 0.1°, while the contact angle of the hydrophobic PEA surface was found to be 122.4 ± 0.1°. By incorporating PEG/SiO2/PNIPAM-PEA Janus particles at a temperature of 25 °C, the foam's half-life is significantly prolonged from 42 s to nearly 30 min. However, with an increase in temperature to 50 °C, the foam's half-life rapidly diminished to only 44 s. This innovative application effectively enhances foam stabilization at low temperatures and facilitates the rapid dissipation of foam at high temperatures.

Exploring Polyol-Functionalized Dendrimers with Silsesquioxane Cores

Silsesquioxane dendrimers offer versatile structural potential, prompting our innovative synthesis of G1 and G2 polyol dendritic systems with diverse silsesquioxane cores, ranging from mono-T8 to difunctional and tetrafunctional double-decker silsesquioxanes. Through a strategic combination of hydrosilylation and O-silylation reactions, we have formed an extensive compound library. A major focus was directed toward investigating the reaction conditions of G1.5 dendrimers, as well as evaluating the stability and reactivity of the novel -O-Me2Si-H group. Notably, we unveiled solubility trends of these synthesized dendritic systems in basic organic solvents, offering vital information for potential applications. Our work advances dendrimer research by unraveling intricate synthesis, reactivity, and properties. We contribute to the broader understanding of these organic-inorganic complex interactions and envisage diverse applications in multiple domains.

Preparation of Non-Spherical Janus Particles via an Orthogonal Dissolution Approach

Post-synthesis modifications are valuable tools to alter functionalities and induce morphology changes in colloidal particles. Non-spherical polymer particles with Janus characteristics are prepared by combining seeded growth polymerization and selective dissolution. First, spherical polystyrene (PS) particles have been swollen with methyl methacrylate (MMA) with an activated swelling method. This is followed by polymerization that led to particles with two well-separated faces: one made of PS and the second of polymethyl methacrylate (PMMA). Subsequently, non-spherical particles are obtained by exposing the Janus colloids to various solvents. Using the two polymers' orthogonal solubility, solvents are identified to selectively dissolve only one face, leading to hemispherical PS or PMMA particles. It is further investigated how changing the composition of the PMMA face - by either co-polymerization with glycidyl methacrylate or by adding a cross-linker - affects the particles' morphology. The poly-methacrylate face can gain total or partial resistance towards the solvents, resulting in intriguing shapes, such as mushroom-like and Janus dimpled particles. The dissolution mechanisms are investigated via optical microscopy, where total or partial dissolutions can be directly observed. Lastly, prematurely quenching the dissolution of the particle's lobes with water can be used to control the Janus mushroom-like particle aspect ratio.

Nanocellulose-based composite aerogels toward the environmental protection: Preparation, modification and applications

Nanocellulose aerogel has the advantages of porosity, low density and high specific surface area, which can effectively realize the adsorption and treatment of wastewater waste gas. The methods of preparing nanocellulose mainly include mechanical, chemical and biological methods. Nanocellulose is formed into nanocellulose aerogel after gelation, solvent replacement and drying processes. Based on the advantages of easy modification of nanocellulose aerogels, nanocellulose aerogels can be functionalized with conductive fillers, reinforcing fillers and other materials to give nanocellulose aerogels in electrical, mechanical and other properties. Through functionalization, the properties of nanocellulose composite aerogel such as hydrophobicity and adsorption are improved, and the aerogel is endowed with the ability of electrical conductivity and electromagnetic shielding. Through functionalization, the applicability and general applicability of nanocellulose composite aerogel in the field of environmental protection are improved. In this paper, the preparation and functional modification methods of nanocellulose aerogels are reviewed, and the application prospects of nanocellulose composite aerogels in common environmental protection fields such as dye adsorption, heavy metal ion adsorption, gas adsorption, electromagnetic shielding, and oil-water separation are specifically reviewed, and new solutions are proposed.

Metallodendrimers Unveiled: Investigating the Formation and Features of Double-Decker Silsesquioxane-Based Silylferrocene Dendrimers

Dendrimers exhibiting reversible redox properties have attracted extensive attention for their potential as electron transfer mediators, catalysts, and molecular sensors. In this study, we introduce intriguing G1 and G2 dendrimers featuring double-decker silsesquioxane cores and silylferrocene moieties. Through a carefully orchestrated sequence of condensation, reduction, and hydrosilylation reactions, these compounds were synthesized and comprehensively characterized spectroscopically and spectrometrically. Our investigation also encompassed the examination of their properties, including thermal stability, solubility in common organic solvents, and electrochemical behavior. We determined that these dendrimers possess the capability to form monolayers on platinum electrodes, which we conclusively demonstrated through the probing of cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy imaging. Notably, this study marks the first-ever example of modifying double-decker silsesquioxane cores with ferrocene groups while simultaneously representing one of the scarce instances of dendrimers exhibiting an open double-decker silsesquioxane core.

A Brief Review on Selected Applications of Hybrid Materials Based on Functionalized Cage-like Silsesquioxanes

Rapid developments in materials engineering are accompanied by the equally rapid development of new technologies, which are now increasingly used in various branches of our life. The current research trend concerns the development of methods for obtaining new materials engineering systems and searching for relationships between the structure and physicochemical properties. A recent increase in the demand for well-defined and thermally stable systems has highlighted the importance of polyhedral oligomeric silsesquioxane (POSS) and double-decker silsesquioxane (DDSQ) architectures. This short review focuses on these two groups of silsesquioxane-based materials and their selected applications. This fascinating field of hybrid species has attracted considerable attention due to their daily applications with unique capabilities and their great potential, among others, in biomaterials as components of hydrogel networks, components in biofabrication techniques, and promising building blocks of DDSQ-based biohybrids. Moreover, they constitute attractive systems applied in materials engineering, including flame retardant nanocomposites and components of the heterogeneous Ziegler-Natta-type catalytic system.

Thermal, Mechanical and Dielectric Properties of Polyimide Composite Films by In-Situ Reduction of Fluorinated Graphene

Materials with outstanding mechanical properties and excellent dielectric properties are increasingly favored in the microelectronics industry. The application of polyimide (PI) in the field of microelectronics is limited because of the fact that PI with excellent mechanical properties does not have special features in the dielectric properties. In this work, PI composite films with high dielectric properties and excellent mechanical properties are fabricated by in-situ reduction of fluorinated graphene (FG) in polyamide acid (PAA) composites. The dielectric permittivity of pure PI is 3.47 and the maximum energy storage density is 0.664 J/cm³ at 100 Hz, while the dielectric permittivity of the PI composite films reaches 235.74 under the same conditions, a 68-times increase compared to the pure PI, and the maximum energy storage density is 5.651, a 9-times increase compared to the pure PI films. This method not only solves the problem of the aggregation of the filler particles in the PI matrix and maintains the intrinsic excellent mechanical properties of the PI, but also significantly improves the dielectric properties of the PI.

Construction of Enzyme-Responsive Micelles Based on Theranostic Zwitterionic Conjugated Bottlebrush Copolymers with Brush-on-Brush Architecture for Cell Imaging and Anticancer Drug Delivery

Bottlebrush copolymers with different chemical structures and compositions as well as diverse architectures represent an important kind of material for various applications, such as biomedical devices. To our knowledge, zwitterionic conjugated bottlebrush copolymers integrating fluorescence imaging and tumor microenvironment-specific responsiveness for efficient intracellular drug release have been rarely reported, likely because of the lack of an efficient synthetic approach. For this purpose, in this study, we reported the successful preparation of well-defined theranostic zwitterionic bottlebrush copolymers with unique brush-on-brush architecture. Specifically, the bottlebrush copolymers were composed of a fluorescent backbone of polyfluorene derivate (PFONPN) possessing the fluorescence resonance energy transfer with doxorubicin (DOX), primary brushes of poly(2-hydroxyethyl methacrylate) (PHEMA), and secondary graft brushes of an enzyme-degradable polytyrosine (PTyr) block as well as a zwitterionic poly(oligo (ethylene glycol) monomethyl ether methacrylate-co-sulfobetaine methacrylate) (P(OEGMA-co-SBMA)) chain with super hydrophilicity and highly antifouling ability via elegant integration of Suzuki coupling, NCA ROP and ATRP techniques. Notably, the resulting bottlebrush copolymer, PFONPN9-g-(PHEMA15-g-(PTyr16-b-P(OEGMA6-co-SBMA6)2)) (P2) with a lower MW ratio of the hydrophobic side chains of PTyr and hydrophilic side chains of P(OEGMA-co-SBMA) could self-assemble into stabilized unimolecular micelles in an aqueous phase. The resulting unimolecular micelles showed a fluorescence quantum yield of 3.9% that is mainly affected by the pendant phenol groups of PTyr side chains and a drug-loading content (DLC) of approximately 15.4% and entrapment efficiency (EE) of 90.6% for DOX, higher than the other micelle analogs, because of the efficient supramolecular interactions of π–π stacking between the PTyr blocks and drug molecules, as well as the moderate hydrophilic chain length. The fluorescence of the PFONPN backbone enables fluorescence resonance energy transfer (FRET) with DOX and visualization of intracellular trafficking of the theranostic micelles. Most importantly, the drug-loaded micelles showed accelerated drug release in the presence of proteinase K because of the enzyme-triggered degradation of PTyr blocks and subsequent deshielding of P(OEGMA-co-SBMA) corona for micelle destruction. Taken together, we developed an efficient approach for the synthesis of enzyme-responsive theranostic zwitterionic conjugated bottlebrush copolymers with a brush-on-brush architecture, and the resulting theranostic micelles with high DLC and tumor microenvironment-specific responsiveness represent a novel nanoplatform for simultaneous cell image and drug delivery.

Synthesis of enzyme-responsive theranostic amphiphilic conjugated bottlebrush copolymers for enhanced anticancer drug delivery

Synthesis of polyfluorene (PF) based theranostic amphiphilic copolymers with simultaneously high drug loading efficiency and tumor microenvironment-specific responsiveness for promoted intracellular drug release and enhanced cancer therapy has been rarely reported likely due to the lack of efficient synthetic approaches to integrate these desirable properties. In this work, we recorded the successful preparation of well-defined theranostic amphiliphilic bottlebrush copolymers composing of fluorescent backbone of PF and tunable enzyme-degradable side chains of polytyrosine (PTyr) and POEGMA by integrating Suzuki coupling, NCA ROP and ATRP techniques. Notably, the resulting copolymer, PF₂₅-g-(PTyr₂₆-b-(POEGMA₂₈)₂ (P₄) with two branched POEGMA brushes tethered to one PTyr termini for each unit could form steady unimolecular micelles with higher fluorescence quantum yield of 18.3% in aqueous and greater entrapment efficiency (EE) of 91.0% for DOX ascribed to the efficient π-π stacking interactions between PTyr blocks and drug molecules and the unique structure of branched hydrophilic brushes with a moderate chain length. DOX@P₄ micelles revealed visualization of intracellular trafficking and accelerated drug release due to the enzyme-triggered degradation of PTyr blocks with proteinase K and subsequent deshielding of POEGMA corona for micelle destruction. In vitro and In vivo animal study further verified the intensive therapeutic efficiency with attenuated systematic toxicity. Taken together, we provided a universal strategy toward multifunctional polymeric delivery vehicles based on conjugated PF and biocompatible and degradable polypeptide by integratied Suzuki coupling and NCA ROP, and identified the branched structure of hydrophilic brushes for better performance of bottlebrush copolymers-based micelles for drug delivery applications. STATEMENT OF SIGNIFICANCE: Synthesis of polyfluorene (PF)-based theranostic amphiphilic copolymers with simultaneously high drug loading efficiency and tumor microenvironment-specific responsiveness for promoted intracellular drug release and enhanced cancer therapy has been rarely reported likely due to the lack of efficient synthetic approaches to integrate these desirable properties. We reported herein successful preparation of enzyme-responsive theranostic amphiliphilic bottlebrush copolymers with simultaneously high drug loading efficiency and tumor microenvironment-specific responsiveness for enhanced chemotherapy in vivo. This study therefore not only developed a universal strategy for the construction of multifunction polymeric vehicles based on the conjugated polymer of PF and degradable polypeptide by integrated Suzuki coupling and NCA ROP, but also emphasized the better stability of micelles endowed by the branched hydrophilic brushes than linear ones.

Investigation of eight-arm tapered star copolymers prepared by anionic copolymerization and coupling reaction

A series of eight-arm tapered star copolymers 8[P(I-co-S)x]-POSS were synthesized by the coupling reaction between octavinyl POSS and the tapered living copolymer chains obtained from statistical anionic copolymerization.