No abstract

We herein report the fabrication of core-crosslinked, fluorescent, and surface-functionalized worm-like block copolymer micelles as drug delivery vehicles. The polyether-based diblock terpolymer [allyl-poly(ethylene oxide)-block-poly(2-ethylhexyl glycidyl ether-co-furfuryl glycidyl ether)] was synthesized via anionic ring opening polymerization, and self-assembly in water as a selective solvent led to the formation of long filomicelles. Subsequent cross-linking was realized using hydrophobic bismaleimides as well as a designed fluorescent cross-linker for thermally induced Diels−Alder reactions with the furfuryl units incorporated in the hydrophobic block of the diblock terpolymer. As a fluorescent cross-linker, we synthesized and incorporated a cyanine 5-based bismaleimide in the cross-linking process, which can be used for fluorescence tracking of the particles. Furthermore, we covalently attached glucose to the allyl end groups present on the surface of the micelles to investigate active glucose-mediated transport into suitable cell lines. First studies in 2D as well as 3D cell culture models suggest a glucose-dependent uptake of the particles into cells despite their unusually large size compared to other nanoparticle systems used in drug delivery.

In this work, a novel dual-response hydrogel for enhanced bone repair following multiple fractures was investigated. The conventional treatment of multiple bone fracture consists on removing smaller bone fragments from the body in a surgery, followed by the fixation of the bone using screws and plates. This work proposes an alternative for this treatment via in situ UV-initiated radical polymerization of a novel IPN hydrogel composed of PAA/P(NiPAAM-co-PEGDMA) incorporated with ceramic additives. The influence of different additives on mechanical properties and sensitivity of the polymer, as well as the prepolymer mixture, were investigated in order to analyse the suitability of the composites for bone healing applications. This material exhibited an interpenetrating network, confirmed by FTIR, with ceramics particles dispersed in between the polymer network. These structures presented high strength by tensile tests, sensitivity to pH and temperature and a decrease on Tg values of NiPAAm depending on the amount of PEGDMA and ceramics added; although, the addition of ceramics to these composites did not decrease their stability drastically. Finally, cytotoxicity tests revealed variations on the toxicity, whereas the addition of TCP presented to be non-toxic and that the cell viability increased when ceramics additives were incorporated into the polymeric matrix with an increased reporter activity of NF-κB, associated with aiding fibroblast adhesion. Hence, it was possible to optimise feedstock ratios to increase the applicability of the prepolymer mixture as a potential treatment of multiple fractures.

We herein report on the synthesis of polyether-based diblock terpolymers and their self-assembly into complex solution structures (e.g. filomicelles). The aggregates were core-crosslinked and their structure was influenced via ultrasonication.

Quinoline photobases exhibit a distinctly higher p K a in their electronically excited state than in the ground state, thereby enabling light‐controlled proton transfer reactions, for example, in molecular catalysis. The absorption of UV light translates to a p K a jump of approximately 10 units, as established for small‐molecule photobases. This contribution presents the first synthesis of quinoline‐based polymeric photobases prepared by reversible addition‐fragmentation chain‐transfer (RAFT) polymerization. The integration of quinolines as photobase chromophores within copolymers offers new possibilities for light‐triggered proton transfer in nanostructured materials, that is, in nanoparticles, at surfaces, membranes and interfaces. To exploit the light‐triggered reactivity of photobases within such materials, we first investigated how the ground‐ and excited‐state properties of the quinoline unit changes upon polymer integration. To address this matter, we combined absorption and emission spectroscopy with time‐resolved transient‐absorption studies to reveal photoinduced proton‐transfer dynamics in various solvents. The results yield important insights into the thermodynamic and kinetic properties of these polymeric quinoline photobases.