Highly stable and polymerizable δ-valerolactones bearing oligo-(ethylene glycol) methyl ether functionalities are facilely prepared by alkylphosphine catalyzed thiol-ene addition with an exocyclic α,β-unsaturated δ-valerolactone. The functionalized lactones undergo efficient ring-opening polymerization (ROP) to afford well defined PEG-like polyesters. Kinetic studies revealed that the ROP, catalyzed by diphenyl phosphate at ambient temperature, shows living nature. The results of cell viability assays indicate that the resultant polyesters are fully biocompatible. In vitro tests on protein adsorption and cell adhesion demonstrate that the antifouling capability of these polyesters is comparable to that of PEG.The strategy for facile preparation of stable and polymerizable lactones bearing functional substituents reported here provides a versatile platform for the development of polyester-based new biocompatible and biodegradable polymeric materials for biomedical applications.Poly(ethylene glycol) (PEG) is a neutral, hydrophilic, and biocompatible polyether that is widely adopted in biomedical applications. PEG is well known as one of the most effective synthetic polymers in reducing non-specific protein adsorption. 1,2 PEGylation has also been extensively exploited on a wide variety of chemical and biomedical entities, including small drugs and pharmaceutical carriers, in order to enhance their biomedical efficacy and physicochemical properties. 3 In fact, PEG is the only synthetic polymer approved by the Food and Drug Administration (FDA) for preparing polymer-protein conjugates. 4,5 However, with the rapidly growing interest in protein-based therapeutics, 6 the inherent nonbiodegradability of PEGs, as one of the major drawbacks, has caused increasing concern. 7,8 High-molecular-weight (high-M w ) PEGs (over 40 kDa) are metabolically inert, with their excretion rates being significantly reduced. 9 Recently, an increasing number of reports have shown that high-M w PEGs can accumulate and cause vacuolation in the liver, kidney, spleen and tissues after administration. 7b-e,10 Growing concern on bioaccumulation and cytoplasmic vacuolization issues of PEG prompted a search for solutions to overcome its limitation of non-biodegradability. One solution is to incorporate cleavable moieties into the backbone of PEG based on step-growth polymerization. 11,12 However, the linear PEG-analogues offered by these approaches are usually not well defined. Many biomedical applications, especially the in vivo ones, would benefit from synthetic polymeric materials with well defined structures (e.g. narrow polydispersity, PDI). 13 Well defined polymethacrylates with cleavable pendant oligomeric poly(ethylene oxide) (PEO) side chains as degradable PEG analogues have been synthesized via controlled radical polymerization, 14-17 but their non-biodegradable carboncarbon backbones could limit their in vivo applications as biomedical materials. 18 Aliphatic poly(ester)s, on the other hand, offer backbones that are biocompatible and bio...

The novel macrocycle RhombicArene features excellent capability for rapid, exclusive, and recyclable vapor adsorption of cyclohexanone in the presence of cyclohexanol, showing potential for energy-saving separation of these feedstock chemicals.

The effects of oligomer length, solvent, and temperature on the self-association of stably folded short aromatic oligoamide are probed. With large flat surfaces, these aromatic oligoamides undergo stacking interaction with strength that increases nonlinearly with oligomer lengths. Opposite to typical aromatic stacking, the stacking of these molecules is enhanced in solvents of low polarity, but it is greatly weakened in polar solvents, especially those with hydrogen bond donors, and it is very sensitive to changes in temperature.