Consensus guidelines for the use and interpretation of angiogenesis assays

The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference

Triazine-mediated controlled radical polymerization: New unimolecular initiators

Triazine-based unimolecular initiators are shown to mediate the controlled radical polymerization of several monomer classes, yielding polymers with low dispersities, targeted molecular weights, and active chain ends. We report the modular synthesis of structurally and electronically diverse triazine-based unimolecular initiators and demonstrate their ability to efficiently control the radical polymerization of modified styrene monomers. Copolymerizations of styrene with butyl acrylate or methyl methacrylate were conducted to highlight the monomer family tolerance of this system. Notably, in the case of methyl methacrylate and styrene, up to 90 mol% methyl methacrylate comonomer loadings could be achieved while maintaining a controlled polymerization, allowing the synthesis of a range of block copolymers. This class of triazine-based mediators has the potential to complement current methods of controlled radical polymerization and marks an important milestone in ongoing efforts to develop initiators and mediators with high monomer tolerance that are both metal and sulfur-free

Controlled drug release to cancer cells from modular one-photon visible light-responsive micellar system

We present a one-photon visible light-responsive micellar system for efficient, on-demand delivery of small molecules. Release is mediated by a novel class of photochromic material - donor-acceptor Stenhouse adducts (DASAs). We demonstrate controlled delivery of small molecules such as the chemotherapeutic agent (paclitaxel) to human breast cancer cells triggered by micellar switching with low intensity, visible light.113118sciescopu

Highly efficient organic photocatalysts discovered via a computer-aided-design strategy for visible-light-driven atom transfer radical polymerization

Organocatalysed photoredox-mediated atom transfer radical polymerization (O-ATRP) is a very promising polymerization method as it eliminates concerns associated with transition-metal contamination of polymer products. However, reducing the amount of catalyst and expanding the monomer scope remain major challenges in O-ATRP. Herein, we report a systematic computer-aided-design strategy to identify powerful visible-light photoredox catalysts for O-ATRP. One of our discovered organic photoredox catalysts controls the polymerization of methyl methacrylate at sub-ppm catalyst loadings (0.5 ppm-a very meaningful amount enabling the direct use of polymers without a catalyst removal process); that is, 100-1,000 times lower loadings than other organic photoredox catalysts reported so far. Another organic photoredox catalyst with supra-reducing power in an excited state and high redox stability facilitates the challenging polymerization of the non-acrylic monomer styrene, which is not successful using existing photoredox catalysts. This work provides access to diverse challenging organic/polymer syntheses and makes O-ATRP viable for many industrial and biomedical applications