Article
Biochemistry & Molecular Biology
Pavel A. Tikhonov, Nataliya G. Vasilenko, Marat O. Gallyamov, Georgii Cherkaev, Viktor G. Vasil'ev, Nina Demchenko, Mikhail Buzin, Sergey G. Vasil'ev, Aziz M. Muzafarov
Summary: New multiarm stars have been synthesized based on high-generation carbosilane dendrimers, leading to steric hindrances and chain transfer reactions during synthesis. Dense nanogel formations with a higher tendency of ordering were isolated from the reaction mixture. The study of the rheology of these multiarm stars suggests a macromolecular nature and a reptation flow mechanism.
Article
Polymer Science
So Yeong Park, Chungryong Choi, Junho Jang, Eunseol Kim, Yeseong Seo, Jaeyong Lee, Jin Kon Kim, Hyeon U. Jeong, Jaeup U. Kim
Summary: The research discovered that under different substrate interactions and molecular weights, thin-film morphology of six-arm star-shaped poly(methyl methacrylate)-b-polystyrene [(PMMA-b-PS)(6)] varies, forming different structural arrangements.
Article
Polymer Science
Kevin A. Waibel, Dafni Moatsou, Michael A. R. Meier
Summary: Linear uniform oligomers are modified with octaethylene glycol monomethyl ether and coupled via azide-alkyne cycloaddition to form uniform star-shaped block macromolecules with a mass ranging from 10 to 14 kDa. Characterized by NMR, ESI-MS, and SEC, these macromolecules are then tested for their ability to encapsulate dye molecules in qualitative solid-liquid phase transfer experiments.
MACROMOLECULAR RAPID COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Melissa A. Reith, Irene De Franceschi, Matthieu Soete, Nezha Badi, Resat Aksakal, Filip E. Du Prez
Summary: The study proposes a robust strategy for the synthesis of sequence-defined, discrete star-shaped macromolecules. The iterative approach allows for the preparation of asymmetrically branched macromolecules with high purity and yields, enabling sequence definition, precise insertion of branching points, and orthogonal end-group functionalization.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Polymer Science
So Yeong Park, Hyeon U. Jeong, Jaeyong Lee, Junho Jang, Sanghoon Kim, Chungryong Choi, Jaeup U. Kim, Jin Kon Kim
Summary: The authors conducted directed self-assembly on thin films of symmetric six-arm star-shaped poly(methyl methacrylate)-block-polystyrene copolymer, adjusting the affinity between each block and the trench wall to fabricate various dual nanopatterns. The observed morphologies, including lines, lamellar layers, and nanotubes, depend on the surface properties of the trench and the treatment method.
MACROMOLECULAR RAPID COMMUNICATIONS
(2021)
Article
Chemistry, Applied
Akram Rahmani, Salar Salmanipour, Yousef Nami, Hassan Zavvar Mousavi, Roya Salehi
Summary: Polymeric micelles produced from novel biodegradable pH-sensitive copolymers have been developed as drug delivery carriers for combination therapy of breast cancer. These micelles can co-deliver hydrophilic and hydrophobic drugs, leading to enhanced cytotoxicity and apoptosis in cancer cells.
REACTIVE & FUNCTIONAL POLYMERS
(2023)
Article
Polymer Science
Nadiia Velychkivska, Ondrej Sedlacek, Anastasiia B. Shatan, Monika Spasovova, Sergey K. Filippov, Mandeep K. Chahal, Larisa Janisova, Jiri Brus, Lenka Hanykova, Jonathan P. Hill, Francoise M. Winnik, Jan Labuta
Summary: Star-shaped porphyrin-PNIPAM(4) (PP) conjugates with four PNIPAM arms connected to a central tetraphenylporphyrin unit were synthesized and their temperature-induced phase-separation behavior was investigated. Compared to PNIPAM homopolymers, the shorter PNIPAM arms of PP conjugates led to a lower phase-separation temperature. Additionally, the size of the cooperative domain of PP was found to be concentration-dependent.
Article
Polymer Science
Qianyu Lin, Chen Chuan Lim, Cally Owh, Joey Hui Min Wong, Valerie Ow, Belynn Sim, Yi Jian Boo, Michelle P. Y. Yew, Yi Hao Leow, Liangfeng Guo, Jason Y. C. Lim, Xian Jun Loh
Summary: Thermogels are a type of supramolecular hydrogels that undergo reversible sol-gel phase transitions and their unique properties depend on the hydrophilic-hydrophobic balance of the constituent polymers. Most thermogelling polymers use polyethylene glycol (PEG) as the hydrophilic segment, but this study introduces PEG-free amphiphilic polymers comprising only polyethylenimine (PEI) and polypropylene glycol (PPG) as the hydrophilic and hydrophobic segments, respectively. These polymers can self-assemble into micelles and supramolecular gel matrices. By modifying the PEI-PPG copolymers with benzyl groups, the resulting thermogel properties can be conveniently modulated. The hydrophobic-hydrophilic balance of the copolymers can also be adjusted to tune the critical gelation concentrations, gelation temperatures, and gel viscoelastic properties. In addition, the PEI segment exhibits pH-responsiveness, allowing for further alteration of thermogel viscoelasticity through pH adjustment. The convenience of postsynthetic functionalization, new material properties, and dual stimuli-responsiveness of these polycationic PEI-PPG thermogels can potentially offer a vast material design space for many unique applications.
Review
Polymer Science
Przemyslaw Kubisa, Grzegorz Lapienis, Tadeusz Biela
Summary: Star-shaped PLA-b-PEG polymers have a more compact structure with more end-groups than linear counterparts, and introducing PEG segments can improve hydrophilicity and change the properties of PLA polymers, expanding their applications in biomedical field. Research on the architecture, number of arms, and content of hydrophilic and hydrophobic blocks of synthesized polymers for potential biomedical applications is emphasized.
POLYMERS FOR ADVANCED TECHNOLOGIES
(2021)
Article
Polymer Science
Hiroomi Kitajima, Shohei Ida, Shukanta Bhowmik, Shin-ichi Yusa, Shokyoku Kanaoka
Summary: A deep understanding of the effect of ionic density in a polymer on solution properties is crucial for the development of novel stimuli-responsive materials. In this study, core-crosslinked multiarm star polymers with ionizable poly(acrylic acid) (PAA) segments were synthesized and their pH-responsive properties were evaluated. It was found that the location of PAA segments in the polymer arms influenced the aggregation behavior and pH-responsive change of the hydrodynamic radius in water, which resulted from the balance of hydrogen bonding and electrostatic repulsion.
Article
Polymer Science
Graham Hayes, Ben Drain, C. Remzi Becer
Summary: Poly(2-oxazoline)s are promising for biomedical applications, but limited synthetic approaches exist for star-shaped polymers. A novel bis-oxazoline cross-linker was developed via a fast thiol click reaction, allowing the preparation of well-controlled core cross-linked star polymers. The synthesized star-shaped polymers were characterized extensively and showed potential for encapsulation of dihydroxyanthroquinone.
Article
Polymer Science
Yeseong Seo, So Yeong Park, Jaeyong Lee, Jin Kon Kim, Chao Duan, Weihua Li
Summary: The morphology formed in a binary blend of two different copolymers can vary depending on the molecular weights and volume fractions, with cylindrical microdomains forming when there is a significant difference in molecular weights and a lamellar morphology observed when the molecular weights are closer. This study also found interesting inverted cylinders formed in certain conditions, with the stability of these structures attributed to factors such as domain swelling and radial distribution of polymer blocks. Self-consistent field theory (SCFT) was used to verify experimental results.
Article
Polymer Science
Hanhong Li, Zhenqi Cheng, Yang Wang, Dong Zhou, Mingji Su, Xianxun Wang, Peixin He, Yuhong Zhang
Summary: A novel drug delivery vehicle, the sPP nanomicelles, has been developed with high encapsulation efficiency, pH responsiveness, and sustainable drug release behavior, showing great potential for therapeutic applications.
MACROMOLECULAR CHEMISTRY AND PHYSICS
(2021)
Article
Biochemistry & Molecular Biology
Ashita Nair, Jiyoon Bu, Jason Bugno, Piper A. Rawding, Luke J. Kubiatowicz, Woo-jin Jeong, Seungpyo Hong
Summary: Dendron micelles have been used as a promising multifunctional delivery system due to their unique molecular structure. A novel poly(amidoamine) dendron-lipid hybrid nanoparticle (DLNP) was prepared as a nanocarrier for drug/gene co-delivery, with generation 3 DLNPs showing higher drug encapsulation efficiency and better gene complexation compared to generation 2 DLNPs. Additionally, D3LNPs were able to avoid endocytosis and lysosomal degradation, leading to increased cellular uptake and enhanced antitumor and gene transfection efficacy.
Article
Chemistry, Multidisciplinary
Razvan Ghiarasim, Crina Elena Tiron, Adrian Tiron, Mihail-Gabriel Dimofte, Mariana Pinteala, Alexandru Rotaru
Summary: Diblock copolymers of polyhistidine can self-assemble into micelles and undergo pH-dependent disassembly. This property has been utilized for designing drug delivery systems targeting tumor environments. In this study, poly(ethylene glycol)-polyhistidine sequences were synthesized using solid-phase peptide synthesis and their ability to self-assemble into micelles, load doxorubicin, and release the drug in a tumor-like pH environment was investigated.
