Manipulation of Bowl-Shaped Nanoparticles Self-Assembled from a Bipyridine Pendant Containing Homopolymer.

The morphological control and transformation of soft nanomaterials are critical for their physical and chemical properties, which can be achieved by dynamically regulating the hydrophilicity of amphiphilic polymers during self-assembly. Herein, an amphiphilic homopolymer poly(N-(2,2'-bipyridine)-4-acrylamide) (PBPyAA) with bipyridine pendants is synthesized, and the effect of various parameters including initial concentration, temperature, pH, and metal ion coordination on the self-assembly behavior and morphology of the assemblies is investigated. Upon changing the initial concentration of PBPyAA, bowl-shaped nanoparticles (BNPs) with precisely controlled diameter, opening size, and thickness are obtained. With the decrease of pH of the solution, the negatively charged surface of BNPs transforms to a positively charged state. Furthermore, the addition of divalent metal ions (Co2+, Mn2+, and Zn2+) induces the transformation of BNPs to vesicles and giant vesicles. The effect of the above factors on the morphology of the assemblies is essential to change the hydrophilicity of PBPyAA dynamically, leading to variation of the local viscosity during self-assembly. Overall, manipulation of the structural parameters of BNPs and transformation of BNPs to vesicles are achieved, providing fresh insights for the precise control of the morphologies of soft nanomaterials.

Physically and Chemically Compartmentalized Polymersomes for Programmed Delivery and Biological Applications.

Multicompartment polymersomes (MCPs) refer to polymersomes that not only contain one single compartment, either in the membrane or in the internal cavity, but also mimic the compartmentalized structure of living cells, attracting much attention in programmed delivery and biological applications. The investigation of MCPs may promote the application of soft nanomaterials in biomedicine. This Review seeks to highlight the recent advances of the design principles, synthetic strategies, and biomedical applications of MCPs. The compartmentalization types including chemical, physical, and hybrid compartmentalization are discussed. Subsequently, the design and controlled synthesis of MCPs by the self-assembly of amphiphilic polymers, double emulsification, coprecipitation, microfluidics and particle assembly, etc. are summarized. Furthermore, the diverse applications of MCPs in programmed delivery of various cargoes and biological applications including cancer therapy, antimicrobials, and regulation of blood glucose levels are highlighted. Finally, future perspectives of MCPs from the aspects of controlled synthesis and applications are proposed.

Polymeric Toroids Derived from the Fusion-Induced Particle Assembly of Anisotropic Bowl-Shaped Nanoparticles.

Polymeric toroids are fascinating soft nanostructures due to their unique geometry and properties, which have shown potential applications in the fields of nanoreactors, drug delivery, cancer therapy, etc. However, facile preparation of polymeric toroids is still challenging. Herein, we propose a fusion-induced particle assembly (FIPA) strategy to prepare polymeric toroids using anisotropic bowl-shaped nanoparticles (BNPs) as a building block. The BNPs are prepared in ethanol by the self-assembly of an amphiphilic homopolymer, poly(N-(2,2'-bipyridyl)-4-acrylamide) (PBPyAA), synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Upon incubation in ethanol above the glass transition temperature (Tg) of PBPyAA, the BNPs gradually aggregate to form trimers and tetramers due to the disturbance of the colloidal stability. With the increase in incubation time, the aggregated BNPs fuse with each other and then form toroids. Notably, we find that only anisotropic BNPs can aggregate and fuse to form toroids rather than spherical compound micelles due to high surface free energy and curvature at the edge of the BNPs. Besides, mathematical calculations further confirm the formation of trimers and tetramers during the FIPA process and the driving force for the formation of toroids. Overall, we propose a fresh insight for the facile preparation of polymeric toroids by the FIPA of anisotropic BNPs.

Polymeric Bowl-Shaped Nanoparticles: Hollow Structures with a Large Opening on the Surface.

Polymeric bowl-shaped nanoparticles (BNPs) are anisotropic hollow structures with large openings on the surface, which have shown advantages such as high specific area and efficient encapsulation, delivery and release of large-sized cargoes on demand compared to solid nanoparticles or closed hollow structures. Several strategies have been developed to prepare BNPs based on either template or template-free methods. For instance, despite the widely used self-assembly strategy, alternative methods including emulsion polymerization, swelling and freeze-drying of polymeric spheres, and template-assisted approaches have also been developed. It is attractive but still challenging to fabricate BNPs due to their unique structural features. However, there is still no comprehensive summary of BNPs up to now, which significantly hinders the further development of this field. In this review, the recent progress of BNPs will be highlighted from the perspectives of design strategies, preparation methods, formation mechanisms, and emerging applications. Moreover, the future perspectives of BNPs will also be proposed.

[Analysis of polymorphic RAPD fragments in P. Taiwanensis Hayata using an integrated microflluidic chip-based system].

Randomly amplified polymorphic DNA (RAPD) markers quickly provide linkage information, especially in conifers where haploid megagametophytes can be used for genotyping. Traditionally use of slab gel electrophresis results in qualitative data that can be manually manipulated to gain semiquantitative information about the polymorphic RAPD fragments. We have proposed the use of an integrated microfluidic chip-based system as a new tool in the analysis of polymorphic RAPD fragments. The chip-based method was found to be very sensitive,requiring much less sample and only quarter the time compared to the agarose gel method. The automated data analysis sizes and quantitates the DNA fragments, thus yielding a more thorough,reproducible, sensitive, and rapid analysis.