Topological effects of macrocyclic polymers: from precise synthesis to biomedical applications

Fluorescence sensing of water in various organic solvents based on a novel cyclic polymer

A sensor capable of sensing of water in various organic solvents ranging from water-soluble to water-miscible solvents is still a challenging task. In this research, a cyclic polymer fluorescence chemosensor (CPFC) has been developed for sensing of water by turn-on model in 9 organic solvents and turn-off model in DMA, where the broadest concentration range and the lowest detection limit was obtained for water in DMA (10 %-90 %) and dioxane (0.011 %), respectively. The sensing mechanism is explored by theory calculation and experimental investigation. The amphiphilic nature endows the polymer probe with great potential for measuring various contaminants from aqueous and nonaqueous mediums. Furthermore, the present search highlights the potential applications of cyclic polymer as fluorescence probes in the field of sensing.

Multi-tunable aggregation behaviors of thermo/pH-responsive toothbrush-like and jellyfish-like copolymers

Rational design of comb-like and linear conjugates comprising PNIPAM and PDMAEMA segments allows the construction of a multi-tunable hierarchical self-assembly platform and insight into the topology effect.

Topology-directed multi-tunable self-assembly of linear and tadpole-shaped amorphous-responsive-crystalline terpolymers

Rational design of ABC linear terpolymer and (c-AB)C tadpole-shaped terpolymer allows the construction of a topology-directed crystallization/thermo/pH-tunable hierarchical self-assembly platform.

Self-Assembled Polymeric Materials: Design, Morphology, and Functional-Oriented Applications

This Review focuses on the current research advances of the synthesis of various amphiphilic block copolymers (ABCs), such as conventional ABCs and newly-presented polyprodrug amphiphiles (PPAs), and the development of corresponding self-assemblies in selective solvents driven by the intermolecular interactions, like noncovalent hydrophobic interactions, π-π interactions, and hydrogen bonds, between ABCs or preformed small polymeric nanoparticles. The design of these assemblies is systematically introduced, and the diverse examples concerning the unique assembly structures along with the fast development of their exclusive properties and various applications in different fields were discussed. Possible perspectives on the existential challenges and glorious future were elucidated finally. We hope this review will provide a convenient way for readers to motivate more evolutional innovative concepts and methods to design next generation of novel polymeric nanoassemblies, and fill the gap between material design and practical applications. This article is protected by copyright. All rights reserved.

Biomaterials applications of cyclic polymers

Cyclic polymers are an intriguing class of polymers due to their lack of chain ends. This unique architecture combined with steric constraints adorn cyclic polymers as well as nano-, micro- and macro-scale materials containing cyclic polymers with distinctive physicochemical properties which can have a profound effect on the performance of these materials in a wide range of applications. Within a biomedical context, biomaterials based on cyclic polymers have shown very distinct properties in terms of biodistribution, pharmacokinetics, drug/gene delivery efficiency and surface activity. This review summarizes the applications of cyclic polymers in the field of biomaterials and highlights their potential in the biomedical field as well as addressing future challenges in this area.

In Situ Loading and Delivery of Short Single- and Double-Stranded DNA by Supramolecular Organic Frameworks

Short DNA represents an important class of biomacromolecules that are widely applied in gene therapy, editing, and modulation. However, the development of simple and reliable methods for their intracellular delivery remains a challenge. Herein, we describe that seven water-soluble, homogeneous supramolecular organic frameworks (SOFs) with a well-defined pore size and high stability in water that can accomplish in situ inclusion of single-stranded (ss) and double-stranded (ds) DNA (21, 23, and 58 nt) and effective intracellular delivery (including two noncancerous and six cancerous cell lines). Fluorescence quenching experiments for single and double end-labeled ss- and ds-DNA support that the DNA sequences can be completely enveloped by the SOFs. Confocal laser scanning microscopy and flow cytometry reveal that five of the SOFs exhibit excellent delivery efficiencies that, in most of the studied cases, outperform the commercial standard Lipo2000, even at low SOF–nucleic acid ratios. In addition to high delivery efficiencies, the water-soluble, self-assembled SOF carriers have a variety of advantages, including convenient preparation, high stability, and in situ DNA inclusion, which are all critical for practical applications in nucleic acid delivery.

Emerging Applications of Fluorogenic and Non-fluorogenic Bifunctional Linkers

Homo- and hetero-bifunctional linkers play vital roles in constructing a variety of functional systems, ranging from protein bioconjugates with drugs and functional agents, to surface modification of nanoparticles and living cells, and to the cyclization/dimerization of synthetic polymers and biomolecules. Conventional approaches for assaying conjugation extents typically rely on ex situ techniques, such as mass spectrometry, gel electrophoresis, and size-exclusion chromatography. If the conjugation process involving bifunctional linkers was rendered fluorogenic, then in situ monitoring, quantification, and optical tracking/visualization of relevant processes would be achieved. In this review, conventional non-fluorogenic linkers are first discussed. Then the focus is on the evolution and emerging applications of fluorogenic bifunctional linkers, which are categorized into hetero-bifunctional single-caging fluorogenic linkers, homo-bifunctional double-caging fluorogenic linkers, and hetero-bifunctional double-caging fluorogenic linkers. In addition, stimuli-cleavable bifunctional linkers designed for both conjugation and subsequent site-specific triggered release are also summarized.

A twin-tailed tadpole-shaped amphiphilic copolymer of poly(ethylene glycol) and cyclic poly(ε-caprolactone): synthesis, self-assembly and biomedical applications

A tadpole-shaped amphiphilic copolymer containing cyclic PCL and two PEG tails, PEG-b-(c-PCL)-b-PEG, was rationally designed and synthesized.