Poly(l-lactide) (PLLA)-based nanoparticles have attracted much attention with respect to applications in drug delivery and nanomedicine as a result of their biocompatibility and biodegradability. Nevertheless, the ability to prepare PLLA assemblies with well-defined shape and dimensions is limited and represents a key challenge. Herein we report access to a series of monodisperse complex and hierarchical colloidally stable 2D structures based on PLLA cores using the seeded growth, "living-crystallization-driven self-assembly" method. Specifically, we describe the formation of diamond-shaped platelet micelles and concentric "patchy" block co-micelles by using seeds of the charge-terminated homopolymer PLLA[PPhMe]I to initiate the sequential growth of either additional PLLA[PPhMe]I or a crystallizable blend of the latter with the block copolymer PLLA-b-P2VP, respectively. The epitaxial nature of the growth processes used for the creation of the 2D block co-micelles was confirmed by selected area electron diffraction analysis. Cross-linking of the P2VP corona of the peripheral block in the 2D block co-micelles using Pt nanoparticles followed by dissolution of the interior region in good solvent for PLLA led to the formation of novel, hollow diamond-shaped assemblies. We also demonstrate that, in contrast to the aforementioned results, seeded growth of the unsymmetrical PLLA BCPs PLLA-b-P2VP or PLLA-b-PAGE alone from 2D platelets leads to the formation of diamond-fiber hybrid structures.

Uniform biodegradable fiber-like micelles and block comicelles via "living" crystallization-driven selfassembly of poly( L -lactide) block copolymers : the importance of reducing unimer self-nucleation via hydrogen bond disruption',

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The gut microbiota represents a large community of microorganisms that play an important role in immune regulation and maintenance of homeostasis. Living bacteria receive increasing interest as potential therapeutics for gut disorders, because they inhibit the colonization of pathogens and positively regulate the composition of bacteria in gut. However, these treatments are often accompanied by antibiotic administration targeting pathogens. In these cases, the efficacy of therapeutic bacteria is compromised by their susceptibility to antibiotics. Here, we demonstrate that a single-cell coating composed of tannic acids and ferric ions, referred to as ‘nanoarmor’, can protect bacteria from the action of antibiotics. The nanoarmor protects both Gram-positive and Gram-negative bacteria against six clinically relevant antibiotics. The multiple interactions between the nanoarmor and antibiotic molecules allow the antibiotics to be effectively absorbed onto the nanoarmor. Armored probiotics have shown the ability to colonize inside the gastrointestinal tracts of levofloxacin-treated rats, which significantly reduced antibiotic-associated diarrhea (AAD) resulting from the levofloxacin-treatment and improved some of the pre-inflammatory symptoms caused by AAD. This nanoarmor strategy represents a robust platform to enhance the potency of therapeutic bacteria in the gastrointestinal tracts of patients receiving antibiotics and to avoid the negative effects of antibiotics in the gastrointestinal tract.

Polymer-based nanoparticles show substantial promise in the treatment and diagnosis of cancer and other diseases. Herein we report an exploration of the cellular uptake of tailored, low dispersity segmented 1D...