Polymer Chemistry Blog

In this paper, Harth and co-workers reported on the synthesis of biodegradable nanoparticles capable of paclitaxel entrapment and demonstrated the ability to control release of paclitaxel by adjusting the single parameter of the particles’ crosslinking density. Additionally, particles with different densities can be mixed to yield various rates of release that can be fast or slow depending on the specific application. The ability of these particles to withstand simulated gastric fluid allows for the possibility of an oral drug delivery route.

An assessment of nanosponges for intravenous and oral drug delivery of BCS class IV drugs: Drug delivery kinetics and solubilization by David M. Stevens, Kelly A. Gilmore and Eva Harth Polym. Chem. 2014, 5, 3551-3554.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

Driven by the interest in developing new efficient methodologies to prepare well-defined grafted poly(1,4-butadiene)s, Fontaine and co-workers used in the present work a consecutive organocatalyzed ring-opening polymerization (ROP)/ROMP route to prepare poly(1,4-butadiene)-g-polyesters from cyclobutenyl macromonomers bearing one or two polyester segment(s) derived from L-lactide (LA) or ε-caprolactone (CL). The products resulting from this strategy represent the first examples of poly(1,4-butadiene)-g-polyesters through the macromonomer route. These results pave the way for more complicated macromolecular architectures, e.g., by modification of the side-chain termini. Moreover, the hydrolytic (bio)degradation potential of the side chains (that can be used as sacrificial domains) of those bottlebrush copolymers makes them attractive candidates to be used for the preparation of complex hollowed nanostructures.

Synthesis and polymerization of cyclobutenyl-functionalized polylactide and polycaprolactone: a consecutive ROP/ROMP route towards poly(1,4-butadiene)-g-polyesters by Flavien Leroux, Véronique Montembault, Sagrario Pascual, William Guerin, Sophie M. Guillaume and Laurent Fontaine Polym. Chem.2014, 5, 3476-3486.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

In their paper, Gao , Yang and co-workers grafted β-cyclodextrins (β-CDs) onto star-shaped poly(glycidyl methacrylate)s (S5-PGMAs) with a straightforward and efficient ring-opening addition of amine groups to result in PGMA–β-CDs, which not only possess good water-solubility and biocompatibility, but also can serve as polymeric supramolecular hosts to form inclusion complexes with suitable guests. They can be easily assembled on the surface of azobenzene-functionalized MSNs via host–guest interactions to obtain MSN@PGMA–β-CD hybrid nanoparticles. The experimental results showed that these types of inorganic–organic hybrid mesoporous nanocomposites possess good cargo encapsulation and release properties, as compared with the simple supramolecular nanovalves with β-CD itself as the gating component, upon activation by light, temperature variation, and competitive binding agents. In addition, the extremely low cytotoxicity of the nanocomposites demonstrated by MTT assay can further broaden their applications in controlled drug release.

Stimuli-responsive biocompatible nanovalves based on β-cyclodextrin modified poly(glycidyl methacrylate) by Qing-Lan Li, Lizhi Wang, Xi-Long Qiu, Yu-Long Sun, Pei-Xi Wang, Yu Liu, Feng Li, Ai-Di Qi, Hui Gao and Ying-Wei Yang Polym. Chem. 2014, 5, 3389-3395.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

In this article, Kamigaito and co-workers cationically polymerized (−)-β-pinene, a major constituent of pine tree oil,  to generate a high-molecular-weight polymer that were subsequently hydrogenated via metal catalysts to give a high-performance, bio-based cycloolefin polymer with an alicyclic backbone. To obtain the high-molecular-weight polymer, the controlled/living cationic polymerization of (−)-β-pinene was investigated by an initiating system, consisting of a protonic acid, a Lewis acid, and an added base, along with an incremental monomer addition technique. These reactions could be performed even at relatively large scales to produce several hundred grams of the polymer, which can be then processed through injection-molding. The synthesized bio-based cycloolefin polymers demonstrated promising potential properties as high performance optical plastics with good processability, low density, high optical transparency, low birefringence, non-hygroscopicity, high mechanical strength, and excellent thermal properties.

Sustainable cycloolefin polymer from pine tree oil for optoelectronics material: living cationic polymerization of β-pinene and catalytic hydrogenation of high-molecular-weight hydrogenated poly(β-pinene) by Kotaro Satoh, Atsuhiro Nakahara, Kazunori Mukunoki, Hiroko Sugiyama, Hiromu Saito and Masami Kamigaito Polym. Chem. 2014, 5, 3222-3230.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

To overcome these drawbacks, Berthelot and co-workers proposed here an innovative process, based on VUV irradiation, which proved efficient not only for surface modification, but also for the bulk modification of industrially relevant polymers such as β-polyvinylidene fluoride (β-PVDF), polyethylene (PE) or fluorinated ethylene propylene (FEP). The authors assumed that VUV irradiation of a PVDF film can induce radical active species at depths up to 50 micrometers, as demonstrated by ESR. Those active species were able to initiate the radical polymerization of a vinylic or acrylate monomer such as acrylic acid through the polymer film, as confirmed by the EDX profile of the film thickness. Similar results were obtained on PE and FEP films, while aromatic polymers such as PET strongly absorbed VUV energy and dissipated it along other pathways. By mixing this process and photolithographic masks, 3D structuration of commercial polymer films was also obtained.

VUV grafting: an efficient method for 3D bulk patterning of polymer sheets by Cecile Baudin, Jean-Philippe Renault, Stephane Esnouf, Serge Palacin and Thomas Berthelot Polym. Chem. 2014, 5, 2990-2996.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

In this study, Garcia and Miller were inspired to develop improved synthetic routes and novel families of polyoxalates, particularly targeting thermal properties that might allow mimicry of  popular packaging thermoplastics. Polyalkylene oxalates and polyarylene oxalates were successfully synthesized via oxalate metathesis polymerization (OMP), a step-growth polymerization that employs acid-catalyzed ester interchange of dimethyl oxalate and a diol in a 1:1 ratio. The process was optimized in the melt and did not require solvents. Aliphatic/aromatic polyoxalate copolymers derived from 1,10- decanediol and resorcinol bis(hydroxyethyl)ether or hydroquinone bis(hydroxyethyl)ether in varying compositions were also prepared and studied. Incorporation of the aromatic diols into the polymer chain generally afforded increased T_g and T_m. Solid-state degradation studies indicated facile water-degradation of the polyoxalates as molecular weights decreased 81-92% over the course of 13 months in humid air.

Polyoxalates from biorenewable diols via Oxalate Metathesis Polymerization by John J. Garcia and Stephen A. Miller Polym. Chem. 2014, 5, 955-961.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

In this work, Gooding and co-workers have demonstrated a generic approach to optimize the sensing capability of porous silicon through a modular polymer conjugation strategy where the surface of the  porous silicon (PSi) was first modified with an antifouling polymer, then an enzyme cleavable link was added which bridged the antifouling polymer and a second sacrificial polymer that was lost upon enzyme cleavage of the peptide. Cleavage of the peptide–polymer network by the appropriate proteinase decreases the average refractive index of the photonic crystal resulting in a change in the reflectivity peak to lower wavelengths (blue-shift). The PSi–polymer constructs were shown to have selectivity towards different MMP enzymes. The approach could easily be tailored for different chemical/biochemical moieties, thus increasing the potential of such smart surfaces for biosensor applications. These structures could be easily expanded for other proteinase enzymes by simply changing the specific peptide sequences.

Optimising the enzyme response of a porous silicon photonic crystal via the modular design of enzyme sensitive polymers by Alexander H. Soeriyadi, Bakul Gupta, Peter J. Reece and J. Justin Gooding Polym. Chem. 2014, 5, 2333-2341.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

In order to increase the range of coronal chemistries available for CDSA protocols a series of highly asymmetric diblock copolymers comprising a PFS block and a polymethacrylate coblock (poly(tert-butylmethacrylate) (PtBMA), poly(n-butylmethacrylate) (PnBMA), and poly(N,N-dimethylaminoethylmethacrylate) (PDMAEMA), were synthesized by sequential living anionic polymerization. Self-assembly of these block copolymers in acetone yielded cylindrical micelles with a crystalline PFS core and a polymethacrylate corona. The cylindrical micelles were fragmented by sonication and the short micelles were successfully used as “seed initiators” to grow longer monodisperse cylindrical micelles with controlled lengths from added unimers via crystallization-driven living self-assembly. Block co-micelles were also prepared by the sequential addition of unimers with a different coronal block to pre-existing cylinders. These nanostructures could be potentially used as scaffolds for the directed deposition of nanoparticles or for electrostatically-induced organization into hierarchically ordered nanomaterials.

Synthesis and crystallization-driven solution self-assembly of polyferrocenylsilane diblock copolymers with polymethacrylate corona-forming blocks by Nina McGrath, Felix H. Schacher, Huibin Qiu, Stephen Mann, Mitchell A. Winnik and Ian Manners Polym. Chem. 2014, 5, 1923-1929.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

In this paper, Bowman and co-workers demonstrated both spatial and temporal control over the CuAAC by the photo-induced generation of the active form of the catalyst Cu(I) to initiate the CuAAC reaction. Tertiary aliphatic amine ligands were used as an electron transfer species to reduce Cu(II) upon irradiation while also functioning as an accelerating agent and as protecting ligands for the Cu(I). Moreover, this catalyst system was demonstrated to be effective, adaptable to organic and aqueous media, and highly selective to the CuAAC reaction.

Evaluation and development of novel photoinitiator complexes for photoinitiating the copper-catalyzed azide–alkyne cycloaddition reaction by Abeer A. Alzahrani, Annette H. Erbse and Christopher N. Bowman Polym. Chem. 2014, 5, 1874-1882.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

In this paper, Yuan and co-workers  reported on voltage-responsive micelles based on the assembly of two biocompatible homopolymers, namely; poly(ethylene glycol) homopolymer modified with β-cyclodextrin (PEG–β-CD) and poly(L-lactide) homopolymer modified with ferrocene (PLLA–Fc). Through host–guest interactions between β-CD and Fc, the two homopolymers connect together, forming a non-covalent supramolecular block copolymer PLLA–Fc/PEG–β-CD. PLLA–Fc/PEG–β-CD can further self-assemble to form stable micelles in aqueous solution. Through electrochemical control, a reversible assembly–disassembly transition of this micellar system was realized and voltage-controlled drug release based on this system was also conducted successfully using paclitaxel as the anticancer agent.

Voltage-responsive micelles based on the assembly of two biocompatible homopolymers by Liao Peng, Anchao Feng, Huijuan Zhang, Hong Wang, Chunmei Jian, Bowen Liu, Weiping Gao and Jinying Yuan Polym. Chem. 2014, 5, 1751-1759.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.