ω-Pentadecalactone (PDL) was copolymerized with lactones of varying sizes (6-, 7-, 9-, and 13-membered rings) in order to characterize the properties of PDL copolymers throughout the lactone range for copolymerizations catalyzed by magnesium 2,6-di-tertbutyl-4-methylphenoxide (Mg(BHT) 2 (THF) 2 ). Kinetics of the copolymerization reactions were studied using quantitative 13 C NMR spectroscopy, which revealed that the polymerization of the smaller, strained lactone monomer occurred rapidly before the incorporation of PDL into the polymer. Furthermore, all polymers were randomly sequenced as a consequence of transesterification side reactions that occurred throughout polymerization. The copolymers were all shown to cocrystallize to produce polymers with melting and crystallization temperatures that displayed a linear relationship with respect to monomer ratio. Differences in degradation behavior of the smaller lactones enabled the synthesis of PDL copolymer materials that displayed independently controllable thermal and degradation properties.

The ‘immortal’ ring-opening polymerization (iROP) of pentadecalactone (PDL), catalysed by magnesium 2,6-di-tert-butyl-4-methylphenoxide (Mg(BHT)2(THF)2) under non-inert conditions is reported for the first time.

We report the one-pot copolymerization of ω-pentadecalactone (PDL) to produce tri- and diblock-like copolymers with the ability to undergo postpolymerization modification. The ε-substituted ε-lactone (εSL), menthide (MI), was copolymerized with PDL to introduce side chain functionality into poly(ω-pentadecalactone) (PPDL) copolymers. The copolymerization was followed by quantitative 13C NMR spectroscopy, which revealed that the polymerization of MI occurred before the incorporation of PDL into the polymer chain to form a block-like copolymer. Transesterification side reactions were not found to occur interblock, although intrablock transesterification side reactions occurred only within the PPDL section. The same effect was demonstrated across a range of relative molar equivalents of monomers, and the generality of the approach was further demonstrated with the copolymerization of PDL with other εSL monomers. Finally, the copolymerization of PDL with an alkene-functionalized εSL was shown to produce one-pot PDL block-like copolymers that could undergo postpolymerization modification by thiol-ene addition to produce block copolymers with a range of characteristics in a simple procedure.

Highly branched poly(N-isopropyl acrylamide-co-1,2 propandiol-3-methacrylate)s with imidazole end groups and containing anthramethyl methacrylate (AMMA) were prepared. The branch points were produced by incorporating a styryl dithioate ester (a RAFT monomer). The inclusion of AMMA ensures that the polymers fluoresce in the blue region so that they can be visualized in cells in culture. The feed composition was designed to provide lower critical solution temperatures (LCST) between 30 and 37 uC, and therefore the polymers are above the LCST at the usual temperature for culture of human cells. Inclusion of 1,2 propandiol-3-methacrylate (GMA) results in the formation of stable aggregates above the LCST rather than flocculated masses of polymer, and these colloidally stable sub-micron particles can undergo phagocytosis into human dermal fibroblasts. The phagocytosis is temperature dependant and does not occur below the LCST (at 30 uC) when the polymers are in the open-chain fully solvated and non-aggregated state.

We describe the first example of particulate materials that can detach cultured cells and then release them intact in a temperature controlled manner. Topologically open microgels composed of water swollen highly branched polymers prepared from poly(N-isopropylacrylamide) (PNIPAM) were modified with a cell-adhesive peptide (GRGDS) to produce particles for gently detaching and then transferring cultured cells to new substrates. The particles bind to cell surface integrins on both dermal fibroblasts and endothelial cells and at temperatures above the lower critical solution temperature (34 C) remove cells from their normal culture substrates. Brief (45 min) cooling of the resultant particle-cell dispersion to beneath 34 C releases the cells to grow on new substrates. This avoids the need for trypsinisation to detach cells or centrifugation to collect cells post-detachment and offers a flexible approach to cell detachment and transport which is compatible with normal cell culture methodologies.

The copolymerization of an ε-substituted ε-lactone, menthide (MI), and a range of nonsubstituted lactones (6-, 7-, 8-, and 9-membered rings) was investigated in order to determine the factors that affect the sequencing of the MI copolymers. Analysis by quantitative 13C NMR spectroscopy showed the copolymerization of MI with a nonsubstituted lactone of ring size 7 or less produced a randomly sequenced copolymer, as a consequence of the smaller lactone polymerizing first and undergoing rapid transesterification as MI was incorporated. Conversely, copolymerization with larger ring lactones (ring size 8 and above) produced block-like copolymers as a consequence of MI polymerizing initially, which does not undergo rapid transesterification side reactions during the incorporation of the second monomer. Terpolymerizations of a small ring lactone, macrolactone, and menthide demonstrated methods of producing lactone terpolymers with different final sequences, depending on when the small ring lactone was injected into the reaction mixture.

Summary: methacrylate networks have a long history of applications in medical technology and much is known of their non‐fouling properties. However, in recent times it has become clear that the swollen nature of these materials may provide some advantages if they are used as scaffolds in tissue engineering. In general however these hydrogels are resistant to protein adsorption and human cells do not easily adhere. In this work we provide an overview of several strategies that are designed to improve the cell‐adhesive properties of hydrogels while maintaining their useful properties, mainly ease of diffusion of nutrients and growth factors. We describe our early attempts at modifying hydrogels based on 2,3‐propandiol ‐1‐methacrylate, with either hydrophobic units or acid groups. Modification with lauryl methacrylate produced an improvement but acid modification failed to provide surfaces that were conducive to cell culture. Much better scaffolds were prepared by amination of epoxy functional 2,3‐propandiol‐1‐methacrylate networks. Optimized materials in this class were shown to be good substrates for the co‐culture of bovine keratocytes with human corneal epithelial cells. We also describe the synthesis and biological properties of methacrylate conetworks, which phase separate during synthesis to give porous amphiphilic materials. Optimization of these materials produces materials that perform as well as tissue culture plastic so that confluent sheets of human dermal fibroblasts can be produced using standard culture techniques.

Herein the first reported preparation of diblock copolymers of the polyethylene-like polyester poly(x-pentadecalactone) (PPDL) via a combination of enzymatic ring-opening polymerization (eROP) and reversible addition-fragmentation chain-transfer (RAFT) polymerization techniques is described. PPDL was synthesized via eROP using Novozyme 435 as a catalyst and a bifunctional initiator/chain transfer agent (CTA) appropriate for the eROP of x-pentadecalactone (PDL) and RAFT polymerization of acrylic and styrenic monomers. Chain growth of the PPDL macro-CTA was performed to prepare acrylic and styrenic diblock copolymers of PPDL, and demonstrates a facile, metal-free, and "greener" alternative to preparing acrylic diblock copolymers of polyethylene (PE). Diblock copolymer architecture was substantiated via analysis of 1 H NMR spectroscopic, UV-GPC chromatographic, DSC onset crystallization (T c ), and MALDI-ToF mass spectrometric data. V C 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3326-3335 The enhanced control over polymer characteristics afforded by using controlled ROP strategies enables the preparation of complex polymer architectures, and therefore, we postulated that the ROP of PDL would enable facile synthesis of diblock copolymers featuring PE-like properties. Despite the promise of this approach, to date the majority of reported copolymers of PPDL have been characterized as statistical 9,19-25 or multiblock 47 copolymers following the ability of lipases and other catalysts to perform intermolecular transesterification reactions alongside the ROP of cyclic esters. Introduction of end-group functionality through choice of initiator and/or end-capping compound has been demonstrated in the enzymatic ring-opening polymerization (eROP) of PDL in the preparation of PPDL macromonomers 16,48-51 and telechelic species. 17,48,49,52,53 However, initiators maintaining cleavable ester bonds typically yield polymers with mixed compositions and end-group functionality. Reported diblock copolymers of PPDL have consequently been limited, however, include the preparation of poly(butadiene)b-PPDL via eROP, initiating from hydroxyl-terminated poly(butadiene), which required fractionation to remove water initiated chains, 54 in addition to poly(e-caprolactone)b-PPDL and PPDL-b-poly(L-lactide) using sequential feed Additional Supporting Information may be found in the online version of this article.