Bioactive poly(2-oxazoline)-based nanomaterials bearing arylalkylamine and benzamide motifs possess intrinsic radical trapping and anti-ferroptosis properties.

Radical trapping agents such as Ferrostatin-1 (Fer-1) are capable of rescuing cells from ferroptosis, an iron-dependent form of cell death. Previously, poly(2-oxazoline)-Fer-1 (POx-Fer-1) conjugates were reported, which possess increased water-solubility and remain active after covalent conjugation of Fer-1. In this study, we break down the structural and functional layers of POx-Fer-1 conjugates and reveal that drug-free POx containing arylalkylamine and benzamide motifs show anti-ferroptosis properties. Intriguingly, even the basic construct poly(2-methyl-2-oxazoline-grad-2-phenyl-2-oxazoline) P(MeOx-grad-PhOx) was found to be active. Therefore, P(MeOx-grad-PhOx) of varying compositions were prepared, characterized by 1H NMR spectroscopy and size exclusion chromatography and investigated with regard to their self-assembly in aqueous solution and activity in an in vitro ferroptosis model. These findings were further explored for the design of defined and bioactive core-crosslinked micelles with intrinsic anti-ferroptosis behaviour. Cellular interaction studies involving C11-BODIPY assays and confocal microscopy investigations revealed lysosomal processing of the nanomaterials and perturbation of ferroptotic cell death through reducing lipid-peroxidation. This study highlights new drug/cargo-free anti-ferroptotic nanomaterials as proof of concept that hold potential for therapy of ferroptosis-associated diseases and highlights the role of nanocarriers in a therapeutic context.

Probing the Biocompatibility and Immune Cell Association of Chiral, Water-Soluble, Bottlebrush Poly(2-oxazoline)s.

Poly(2-oxazoline)s (POx) have received substantial attention as poly(ethylene glycol) (PEG) alternatives in the biomedical field due to their biocompatibility, high functionality, and ease of synthesis. While POx have demonstrated strong potential as biomaterial constituents, the larger family of poly(cyclic imino ether)s (PCIE) to which POx belongs remains widely underexplored. One highly interesting sub-class of PCIE is poly(2,4-disubstituted-2-oxazoline)s (PdOx), which bear an additional substituent on the backbone of the polymers' repeating units. This allows fine-tuning of the hydrophilic/hydrophobic balance and renders the PdOx chiral when enantiopure 2-oxazoline monomers are used. Herein, we synthesize new water-soluble (R-/S-/RS-) poly(oligo(2-ethyl-4-methyl-2-oxazoline) methacrylate) (P(OEtMeOxMA)) bottlebrushes and compare them to well-established PEtOx- and PEG-based bottlebrush controls in terms of their physical properties, hydrophilicity, and biological behavior. We reveal that the P(OEtMeOxMA) bottlebrushes show a lower critical solution temperature behavior at a physiologically relevant temperature (∼44 °C) and that the enantiopure (R-/S-) variants display a chiral secondary structure. Importantly, we demonstrate the biocompatibility of the chiral P(OEtMeOxMA) bottlebrushes through cellular association and mouse biodistribution studies and show that these systems display higher immune cell association and organ accumulation than the two control polymers. These novel materials possess properties that hold promise for applications in the field of nanomedicine and may be beneficial carriers for therapeutics that require enhanced cellular association and immune cell interaction.

A Homochiral Poly(2-oxazoline)-based Membrane for Efficient Enantioselective Separation.

Chiral separation membranes have shown great potential for the efficient separation of racemic mixtures into enantiopure components for many applications, such as in the food and pharmaceutical industries; however, scalable fabrication of membranes with both high enantioselectivity and flux remains a challenge. Herein, enantiopure S-poly(2,4-dimethyl-2-oxazoline) (S-PdMeOx) macromonomers were synthesized and used to prepare a new type of enantioselective membrane consisting of a chiral S-PdMeOx network scaffolded by graphene oxide (GO) nanosheets. The S-PdMeOx-based membrane showed a near-quantitative enantiomeric excess (ee) (98.3±1.7 %) of S-(-)-limonene over R-(+)-limonene and a flux of 0.32 mmol m-2 h-1 . This work demonstrates the potential of homochiral poly(2,4-disubstituted-2-oxazoline)s in chiral discrimination and provides a new route to the development of highly efficient enantioselective membranes using synthetic homochiral polymer networks.

Phytochemical Profiling and Biological Activity of the Australian Carnivorous Plant, Drosera magna.

Phytochemical profiling was undertaken on the crude extracts of Drosera magna to determine the nature of the chemical constituents present. In total, three new flavonol diglycosides (1-3), one new flavan-3-ol glycoside (4), and 12 previously reported compounds of the flavonol (5, 9), flavan-3-ol (15), flavanone (8), 1,4-napthoquinone (6, 7, 13, 14), 2,3-dehydroxynapthalene-1,4-dione (10-12), and phenolic acid (16) structure classes were isolated and identified. Compounds 1-9, 13, 17, and 18 were assessed for antimicrobial activity, with compounds 6, 7, 8, and 9 showing significant activity. Compounds 1, 2, and 6 were also evaluated for anthelmintic activity against larval forms of Hemonchus contortus, with compound 6 being active.

Hyperbranched Poly(2-oxazoline)s and Poly(ethylene glycol): A Structure-Activity Comparison of Biodistribution.

In light of research reporting abnormal pharmacokinetic behavior for therapeutics and formulations containing poly(ethylene glycol) (PEG), a renewed emphasis has been placed on exploring alternative surrogate materials and tailoring specific materials to distinct nanomedicine applications. Poly(2-oxazolines) (POx) have shown great promise in this regard; however, a comparison of POx and PEG interactions with components of the immune system is needed to inform on their distinct suitability. Herein, the interaction of isolated immune cells following injection of hyperbranched polymers comprised of PEG or hydrophilic POx macromonomers was determined via flow cytometry. All materials showed similar association with all of the splenic immune cells analyzed. Interestingly, splenic CD68hi and CD11bhi macrophages showed similar levels of polymer association, despite CD11bhi being a smaller population, suggesting CD68 is linked to increased recognition and phagocytosis of these nanomaterials. This is of interest given that CD68 is a scavenger receptor and directly facilitates the clearance of cellular debris and promotion of phagocytosis, as opposed to CD11b, which is associated with the mediating inflammation via the production of cytokines as well as complement-mediated uptake of foreign particles. In the liver, PEG and poly(2-methyl oxazoline) hyperbranched polymers showed no discernible differences in their cellular association, while hyperbranched poly(2-ethyl oxazoline) showed increased association with dendrocytes and CD68hi macrophages, suggesting that this material exhibited a greater propensity to interact with components of the immune system. This work highlights the importance of how subtle changes in chemical structure can influence the immune response.

Tuning Cellular Interactions of Carboxylic Acid-Side-Chain-Containing Polyacrylates: The Role of Cyanine Dye Label and Side-Chain Type.

Cellular uptake and intracellular targeting to specific organelles are key events in the cellular processing of nanomaterials. Herein, we perform a detailed structure-property relationship study on carboxylic acid-side-chain-bearing polyacrylates to provide design criteria for the manipulation of their cellular interactions. Redox-initiated reversible addition-fragmentation chain-transfer (RRAFT) polymerization of three tert-butyl-protected N-acylated amino ester-based acrylate monomers of different substitutions and degrees of polymerization (DPs) yielded defined and pH-responsive carboxylic acid-side-chain polymers upon deprotection (N-acetyl, DP 1: P(M1); N-propionyl, DP 1: P(E1), DP 2: P(E2)). Flow cytometry studies revealed time-dependent cell association with P(E2) > P(E1) > P(M1) at any given time point. Importantly, the type of cyanine dye used for labeling was found to significantly influence the cellular processing of the polymers. Changing the dye from Cy5 to its sulfonated version sulfoCy5 resulted in a much lower cellular association. Moreover, Cy5-labeled polymers were targeted to mitochondria, while sulfoCy5 modification caused a significant change in the cellular fate of polymers toward lysosome trafficking. This study highlights the importance of selecting a suitable dye but also demonstrates the possibilities for the rational design of organelle-specific targeting of carboxylated polyacrylates.

Playing in or out of character: user role differences in the experience of interactive storytelling.

Interactive storytelling (IS) is a promising new entertainment technology synthesizing preauthored narrative with dynamic user interaction. Existing IS prototypes employ different modes to involve users in a story, ranging from individual avatar control to comprehensive control over the virtual environment. The current experiment tested whether different player modes (exerting local vs. global influence) yield different user experiences (e.g., senses of immersion vs. control). A within-subject design involved 34 participants playing the cinematic IS drama "Emo Emma"( 1 ) both in the local (actor) and in global (ghost) mode. The latter mode allowed free movement in the virtual environment and hidden influence on characters, objects, and story development. As expected, control-related experiential qualities (effectance, autonomy, flow, and pride) were more intense for players in the global (ghost) mode. Immersion-related experiences did not differ over modes. Additionally, men preferred the sense of command facilitated by the ghost mode, whereas women preferred the sense of involvement facilitated by the actor mode.