Synthesis and crystallization-driven solution self-assembly of PE-b-PMMA: controlling Micellar morphology through crystallization temperature and molar mass

Thermodynamics driving phytochemical self-assembly morphological change and efficacy enhancement originated from single and co-decoction of traditional chinese medicine

Through the self-assembled strategy to improve the clinical efficacy of the existing drugs is the focus of current research. Herbal formula granule is a kind of modern dosage form of traditional Chinese medicine (TCM) which has sprung up in recent decades. However, whether it is equivalent to the TCM decoction that has been used for thousands of years has always been a controversial issue. In this paper, taking the herb pair of Coptidis Rhizoma-Scutellariae Radix and its main component berberine-baicalin as examples, the differences and mechanisms of self-assemblies originated from the co-decoction and physical mixture were studied, respectively. Moreover, the relationship between the morphology and antibacterial effects of self-assemblies was illuminated via multi-technology. Our study revealed that the physical mixture's morphology of both the herb pair and the phytochemicals was nanofibers (NFs), while their co-decoction's morphology was nanospheres (NPs). We also found that the antibacterial activity was enhanced with the change of self-assemblies' morphology after the driving by thermal energy. This might be attributed to that NPs could influence amino acid biosynthesis and metabolism in bacteria. Current study provides a basis that co-decoction maybe beneficial to enhance activity and reasonable use of herbal formula granule in clinic.

Emerging applications for living crystallization-driven self-assembly

The use of crystallization as a tool to control the self-assembly of polymeric and molecular amphiphiles in solution is attracting growing attention for the creation of non-spherical nanoparticles and more complex, hierarchical assemblies. In particular, the seeded growth method termed living crystallization-driven self-assembly (CDSA) has been established as an ambient temperature and potentially scalable platform for the preparation of low dispersity samples of core-shell fiber-like or platelet micellar nanoparticles. Significantly, this method permits predictable control of size, and access to branched and segmented structures where functionality is spatially-defined. Living CDSA operates under kinetic control and shows many analogies with living chain-growth polymerizations of molecular organic monomers that afford well-defined covalent polymers of controlled length except that it covers a much longer length scale (ca. 20 nm to 10 μm). The method has been applied to a rapidly expanding range of crystallizable polymeric amphiphiles, which includes block copolymers and charge-capped homopolymers, to form assemblies with crystalline cores and solvated coronas. Living CDSA seeded growth methods have also been transposed to a wide variety of π-stacking and hydrogen-bonding molecular species that form supramolecular polymers in processes termed "living supramolecular polymerizations". In this article we outline the main features of the living CDSA method and then survey the promising emerging applications for the resulting nanoparticles in fields such as nanomedicine, colloid stabilization, catalysis, optoelectronics, information storage, and surface functionalization.