Glycol Oligomers Research Articles

Luminescent Helical Nanofiber Self-Assembled from a Cholesterol-Based Metalloamphiphile and Its Application in DNA Conformation Recognition

Compared to pure organic amphiphiles, metalloamphiphiles display distinctive features, including luminescence, magnetism and catalytic properties. However, the self-organization of metalloamphiphiles is commonly driven by solvophobic effects. Alkyl chains and oligomeric ethylene glycol moieties are thus the most frequently used aggregation units to drive the self-assembly of metalloamphiphiles. We expect novel metallo-supramolecular structures with exciting functions to be created if additional noncovalent interaction modes are incorporated. In this work, a new type of metalloamphiphile, consisting of a Tb(III) complex head and a cholesteryl unit (TbL3+(I)), was designed and synthesized. TbL3+(I) spontaneously self-assembles into helical nanofibers (d = 6 nm) in water. This synthetic multivalent nanoscale binding array displays powerful capability for the recognition of DNA conformations through a turn-on luminescence sensing mechanism. ssDNA-kit1 triggered a 26-fold increase in the luminescence intensity of TbL3+(I). Its corresponding G-quadruplex structure (G-quadruplex-kit1), however, induced a 6.6-fold enhancement under the same conditions. Consequently, TbL3+(I) nanofibers can monitor DNA folding. In contrast, neither ssDNA-kit1 nor G-quadruplex-kit1 markedly promoted the luminescence of molecularly dispersed TbL3+(II), illustrating that the multivalent electrostatic interactions between the phosphate groups on the backbone of DNA and TbL3+(I) self-assembled into nanofibers could greatly improve the efficiency of the energy transfer between the guanine units and the organized TbL3+(I). The TbL3+(I) nanofibers could bind and distinguish not only the kit1-ssDNA/G-quadruplex but also the conformations of other G-rich DNA, such as spb1, htelo, and intermolec-htelo. The self-assembly of luminescent metalloamphiphiles thus provides a general and convenient strategy for the efficient recognition and conversion of molecular information.

Enhanced Glutathione Peroxidase Activity of Water-Soluble and Polyethylene Glycol-Supported Selenides, Related Spirodioxyselenuranes, and Pincer Selenuranes.

Diaryl selenides containing o-hydroxymethylene substituents function as peroxide-destroying mimetics of the antioxidant selenoenzyme glutathione peroxidase (GPx), via oxidation to the corresponding spirodioxyselenuranes with hydrogen peroxide and subsequent reduction back to the original selenides with glutathione. Parent selenides with 3-hydroxypropyl or 2,3-dihydroxypropyl groups produced the novel compounds 10 and 11, respectively, with greatly improved aqueous solubility and catalytic activity. The phenolic derivative 28 displayed similarly ameliorated properties and also modest radical-inhibiting antioxidant activity, as evidenced by an assay based on phenolic hydrogen atom transfer to the stable free radical DPPH. In contrast, several selenides that afford pincer selenuranes (e.g., 20 and 21) instead of spiroselenuranes upon oxidation showed inferior catalytic activity. Several selenide analogues were attached to polyethylene glycol (PEG) oligomers, as PEG substituents can improve water solubility and bioavailability, while retarding clearance. Again, the PEG derivatives afforded remarkable activity when oxidation generated spirodioxyselenuranes and diminished activity when pincer compounds were produced. Several such compounds proved to be ca. 10- to 100-fold catalytically superior to the diaryl selenides and their spirodioxyselenurane counterparts investigated previously. Finally, an NMR-based assay employing glutathione in D2O was designed to accommodate the faster reacting water-soluble mimetics and to more closely duplicate in vivo conditions.

Simultaneous small-angle neutron scattering and Fourier transform infrared spectroscopic measurements on cocrystals of syndiotactic polystyrene with polyethylene glycol dimethyl ethers

Syndiotactic polystyrene (sPS) is a crystalline polymer which has a unique property; it is able to form cocrystals with a wide range of chemical compounds, in which the guest molecules are confined in the vacancies of the host sPS crystalline region. Recently, it has been found that even polyethylene glycol oligomers with a molecular weight of more than several hundreds can be introduced into the sPS crystalline region. It is quite important to know how such a long-chain molecule is stored in the host sPS lattice. To tackle this issue, a new simultaneous measurement method combing small-angle neutron scattering and Fourier transform infrared spectroscopy (SANS/FTIR), which has been recently developed by the authors, was applied to an sPS cocrystal with polyethylene glycol dimethyl ether with a molecular weight of 500 (PEGDME500). The temperature-dependent changes of the SANS profile and FTIR spectrum were followed from room temperature up to 413 K for a one-dimensionally oriented SANS/PEGDME500 cocrystal sample. The intensity of the reflections due to the stacking of crystalline lamellae showed a significant temperature dependence. The two-dimensional pattern in the high Q region of SANS also changed depending on temperature. The combined information obtained by SANS and FTIR suggested that PEGDME500 molecules are distributed in both the crystalline and amorphous regions in the low-temperature region close to room temperature, but they are predominantly included in the amorphous region in the high-temperature region. It was also suggested by the two-dimensional SANS profile that PEGDME500 molecules in the crystalline region have an elongated structure along the thickness direction of the crystalline lamellae.

Effect of polyethylene glycol-intercalated organoclay on vulcanization characteristics and reinforcement of natural rubber nanocomposites

Organically modified montmorillonite (OMMT) clay was intercalated with low-molecular weight polyethylene glycol (PEG) oligomer at melt stage. The intercalation behaviour of PEG into the OMMT clay galleries and its interaction with clay platelets were characterized with X-ray diffraction (XRD) and differential scanning calorimetric techniques. A natural rubber (NR)–organoclay nanocomposite (NROCN) was prepared by melt-compounding of NR with PEG-treated organoclay (P-OMMT) and other compounding chemicals using a laboratory-scale internal mixer. XRD analysis of the nanocomposites revealed the intercalation of NR molecules into the P-OMMT clay galleries and subsequent exfoliation during the melt-compounding process. Vulcanization characteristics of the NROCN, especially processing safety and optimum curing time, have been interpreted with reference to the organic modifier of the montmorillonite clay, PEG modification and the degree of exfoliation. Solid-state mechanical properties of P-OMMT clay-filled NROCN vulcanizates have shown a significant enhancement in stiffness and strength characteristics whilst without scarifying the elasticity of the nanocomposites. Results have been explained in terms of the degree of exfoliation, dispersibility of the organoclay and strain-induced crystallization of the natural rubber.

Simple processes for the preparation of superhydrophobic polymer surfaces

Abstract Two simple processes; (i) spin-coating, and (ii) doctor blade coating of silica/polymer dispersions are described for the preparation of superhydrophobic polymer surfaces. To demonstrate the versatility and broad applicability of the processes, polymeric surfaces modified included a thermoplastic resin, polystyrene (PS) and a thermoset, crosslinked epoxy resin (ER). Micro/nano hierarchical nature of the surface topographies obtained were demonstrated by scanning electron microscopy (SEM), atomic force microscopy (AFM) and white light interferometry (WLI) studies. Roughness factor (r) and average surface roughness (Ra) values, which are critical in obtaining superhydrophobic surfaces were determined for each polymeric system. It was clearly demonstrated that increased (r) and (Ra) values resulted in superhydrophobic behavior with very high static, advancing and receding water contact angles, well above 150° and contact angle hysteresis values of less than 10°. Incorporation of small amounts (1.0% by weight) of a silicone copolymer or a perfluoroether glycol oligomer reduced the contact angle hysteresis in the epoxy resin system well below 10° and produced truly superhydrophobic surfaces.

Biomimetic Spider-web like Electrospun Nanofbrous Membrane of Nylon-6 for Future Air Filtration

In this work, methoxy poly(ethylene glycol) (MPEG) oligomer with viscous supporting nylon-6 solution was fabricated in the form of natural spider-web like structure via an electrospinning process. Field-emission scanning electron microscopy (FE-SEM) showed that this network consists of thinner MPEG nanofbers, approximately 15 ± 5 nm in diameter connected with thicker nylon-6 main nanofbers, arranged in spider-web like structure. TGA and XRD analysis showed that the hybrid mat of MPEG and nylon-6 was formed during electrospinning. These two different interconnected nanofbers were separated by extraction of MPEG from the fbrous mat in cold water and identifed. The molecular weight and purity of the extracted MPEG was determined by gel permeation chromatography (GPC) and Fourier transform infrared (FT-IR) analysis, respectively. The decreased average pore diameter and increased hydrophilicity of the hybrid mat, caused by spider-web like structure, can make it as a potential candidate for air fltration. Journal of the Institute of Engineering, 2015, 11(1): 108-115

The impact of crystallization conditions on structure-based drug design: A case study on the methylene blue/acetylcholinesterase complex.

Structure-based drug design utilizes apoprotein or complex structures retrieved from the PDB. >57% of crystallographic PDB entries were obtained with polyethylene glycols (PEGs) as precipitant and/or as cryoprotectant, but <6% of these report presence of individual ethyleneglycol oligomers. We report a case in which ethyleneglycol oligomers' presence in a crystal structure markedly affected the bound ligand's position. Specifically, we compared the positions of methylene blue and decamethonium in acetylcholinesterase complexes obtained using isomorphous crystals precipitated with PEG200 or ammonium sulfate. The ligands' positions within the active-site gorge in complexes obtained using PEG200 are influenced by presence of ethyleneglycol oligomers in both cases bound to W84 at the gorge's bottom, preventing interaction of the ligand's proximal quaternary group with its indole. Consequently, both ligands are ∼3.0Å further up the gorge than in complexes obtained using crystals precipitated with ammonium sulfate, in which the quaternary groups make direct π-cation interactions with the indole. These findings have implications for structure-based drug design, since data for ligand-protein complexes with polyethylene glycol as precipitant may not reflect the ligand's position in its absence, and could result in selecting incorrect drug discovery leads. Docking methylene blue into the structure obtained with PEG200, but omitting the ethyleneglycols, yields results agreeing poorly with the crystal structure; excellent agreement is obtained if they are included. Many proteins display features in which precipitants might lodge. It will be important to investigate presence of precipitants in published crystal structures, and whether it has resulted in misinterpreting electron density maps, adversely affecting drug design.

Prediction of the vapor–liquid equilibrium of chemical reactive systems containing formaldehyde using the COSMO-RS method

We herein present a quantum chemical method for predicting the thermodynamic properties of a reactive formaldehyde + water system. The TURBOMOLE program was used to obtain the σ profiles of poly(oxymethylene) glycol oligomers produced via a series of chemical reactions in aqueous solution. The conductor-like screening model for real solutions (COSMO-RS) method, in combination with chemical equilibrium constants and the mass balance equation obtained using MATLAB, was successfully used to calculate the activity coefficients of all compounds in the liquid. Based on NMR data from the literature along with the obtained activity coefficients, we modified the thermodynamic chemical equilibrium constant Kn∗ for glycol formation. Finally, we estimated the vapor–liquid equilibrium and distribution of oligomers (MGn, n ≥ 1) in the formaldehyde-water solution. The COSMO-RS method was thus proven to be an efficient tool to study formaldehyde-containing aqueous solutions, and can be used as a basis for other similar reactive systems.

Partial Molar Volumes and Partial Molar Isentropic Compressions of Four Poly(ethylene glycols) at Infinite Dilution in Water at Temperatures T = (278 to 343) K and Atmospheric Pressure

Density and speed of sound data for dilute aqueous solutions of four poly(ethylene glycol) oligomers were measured using the Anton Paar DSA 5000 vibrating-tube densimeter and sound analyzer in the temperature range from (278.15 to 343.15) K and at atmospheric pressure. Standard molar volumes and standard molar isentropic compressions were evaluated from the measured data. Present data were compared with values available for linear aliphatic polyethers and alkane-α,ω-diols and structure–property relationships were analyzed.

Application of a Human Intestinal Epithelial Cell Monolayer to the Prediction of Oral Drug Absorption in Humans as a Superior Alternative to the Caco-2 Cell Monolayer

A human small intestinal epithelial cell (HIEC) monolayer was recently established in our laboratories as a novel system to evaluate the Papp (apparent permeability coefficient) of compounds during their absorption in humans. An effusion-based analysis using polyethylene glycol oligomers with molecular weights ranging from 194-898 indicated that HIEC and Caco-2 cell monolayers both had paracellular pores with 2 distinct radiuses (∼5 and 9-14 Å), whereas the porosity of large pores was 11-fold higher in the HIEC monolayer (44 × 10−8) than in the Caco-2 cells (4 × 10−8). A comparison between the fraction-absorbed (Fa) values observed in humans and those predicted from Papp values in both monolayers indicated that the HIEC monolayer had markedly higher precision to predict Fa values with root mean square error of 9.40 than the Caco-2 cells (root mean square error = 16.90) for 10 paracellularly absorbed compounds. Furthermore, the accuracy of the HIEC monolayer to classify the absorption of 23 test drugs with diverse absorption properties, including different pathways in the presence or absence of susceptibility to efflux transporters, was higher than that of the Caco-2 cell monolayer. In conclusion, the HIEC monolayer exhibited advantages over Caco-2 cells in the ranking and prediction of absorption of compounds in humans.

Tough biodegradable mixed-macromer networks and hydrogels by photo-crosslinking in solution

The preparation of polymeric networks that are both tough and biodegradable remains a challenge. Here we show a very straightforward method to produce tough biodegradable networks from low molecular weight macromers for applications such as tissue engineering. Photo-crosslinking combinatorial mixtures of methacrylate-functionalized poly(1,3-trimethylene carbonate) (PTMC), poly(d,l-lactide) (PDLLA), poly(ε-caprolactone) (PCL) and poly(ethylene glycol) (PEG) oligomers in propylene carbonate (PC) allowed the preparation of network films with excellent tensile characteristics and resistance to tearing. This method enabled the production of both very tough mixed-macromer elastomers as well as mixed-macromer hydrogels. A mixed-macromer hydrogel prepared from 33wt.% PTMC, 33wt.% PCL and 33wt.% PEG had a very high tearing energy of 0.81kJ/m2, which is comparable to tearing energies determined for articular cartilage.

Synthesis of thermo-responsive polysiloxanes grafted by oligomeric ethylene oxide and their intelligent membranes

Thermal responsive polymers, as a kind of smart materials that can undergo a reversible phase transition from soluble to insoluble status in water upon temperature change, have recevied a broad interests in various interesting fields, such as protein adsorption, tissue engineering and drug delivery. In recent years, lots of efforts were devoted to the synthesis of novel thermo-responsive ploymers with various kinds of amphiphilic structures. Due to its intrinsic hydrophobicity and biocompatibility, polysiloxane has been widely studied in thermo-responsive materials. In this study, thermo-responsive polysiloxanes containing oligomeric ethylene glycol (PMHS-OEG3) were successfully prepared by the highly efficient hydrosilylation reaction between polymethylhydrosiloxane (PMHS)and tri(ethylene glycol)allyl methyl ether with Karstedts catalyst. The PMHS-OEG3s were characterized by NMR, FTIR and UV-vis spectra. They showed the expected amphiphilic and thermoresponsive properties in an aqueous solution. Their Cloud Point (CP)decreased gradually with the increase of their degree of polymerization (DP)and could be tuned from 29.4℃ to 27.5℃. After cured with 1,3-divinyl-1, 1,3,3-tetramethyl disiloxane (MViMVi), the PMHS-OEG3s were crosslinked into smart thermo-responsive membranes and their inherent responsive character could also modulated by the DP of the PMHS-OEG3.

A mass spectrometric study and computer modeling of noncovalent interactions of cytosine with polyethylene glycol oligomers

Data on intermolecular noncovalent interactions of nitrogen base components of nucleic acid with organic polyethers are of interest both for fundamental molecular biophysics and for applications in the production of pharmaceutical organic nanoparticles. In the present work, systems composed of pyrimidine nitrogen base cytosine (Cyt) or its methyl derivatives and polyethylene glycol PEG-400 oligomers Mn have been examined by electrospray ionization (ESI) and fast atom bombardment mass spectrometry. Detection of a set of associates of the Mn · Cyt · H+ type (n = 3–17) in ESI mass spectra evidences the formation of protonated complexes of the base with oligomers of different chain lengths in all of the studied systems. Computer modeling by molecular dynamics gave answers to the questions concerning the stability and structure of these complexes under different conditions. It has been shown that Mn · Cyt · H+ clusters in the gas phase (vacuum) adopt a compact structure with a quasi-cyclic or quasi-helical self-organization of the polymer chain around the protonated base. It has been found that the compact structure of the M8 · Cyt · H+ complex characteristic for its state in the gas phase is preserved in a liquid medium of methanol (used as a solvent in ESI). The results of simulation of the evolution of a methanol droplet in vacuum, which mimics the droplet disintegration under ESI conditions, have shown that the M8 · Cyt · H+ complex initially present in the droplet does not disintegrate in the course of droplet evaporation. After the completion of desolvation, the complex returns to the conformation characteristic for the gas phase. Thus, the evidence has been found confirming that the M8 · Cyt · H+ clusters recorded in ESI mass spectra adequately reflect the presence of corresponding noncovalent complexes in the analyzed liquid solution.

Ludwig-Soret effect of aqueous solutions of ethylene glycol oligomers, crown ethers, and glycerol: Temperature, molecular weight, and hydrogen bond effect.

The thermal diffusion, also called the Ludwig-Soret effect, of aqueous solutions of ethylene glycol oligomers, crown ethers, and glycerol is investigated as a function of temperature by thermal diffusion forced Rayleigh scattering. The Soret coefficient, ST, and the thermal diffusion coefficient, DT, show a linear temperature dependence for all studied compounds in the investigated temperature range. The magnitudes and the slopes of ST and DT vary with the chemical structure of the solute molecules. All studied molecules contain ether and/or hydroxyl groups, which can act as acceptor or donor to form hydrogen bonds, respectively. By introducing the number of donor and acceptor sites of each solute molecule, we can express their hydrogen bond capability. ST and DT can be described by an empirical equation depending on the difference of donor minus acceptor sites and the molecular weight of the solute molecule.

Reversible and Irreversible Adsorption Energetics of Poly(ethylene glycol) and Sorbitan Poly(ethoxylate) at a Water/Alkane Interface.

We simulate poly(ethylene glycol) (PEG) oligomers and model Tween 80 (polyoxyethylene sorbitan monooleate) molecules at water/alkane interfaces. Using the weighted histogram analysis method (WHAM), including an extension of WHAM to two reaction coordinates to remove hysteresis, we calculate interfacial potentials of mean force (PMFs) for PEG and Tween 80 using three force fields: the atomistic GROMOS 53a6OXY+D and two coarse-grained (CG) MARTINI force fields. Because the force fields have not yet been validated for PEO adsorption to hydrophobic interfaces, we calculate PMFs for alcohol ethoxylates C12E2 and C12E8 and find that they agree with semiempirical results of Mulqueen and Blankschtein [Langmuir 2002, 18 (2), 365-376] for the GROMOS 53a6OXY+D force field, whereas for both MARTINI force fields, PEO adsorbs too weakly to a clean hydrophobic interface. One MARTINI force field incorrectly shows depletion rather than adsorption to a clean hydrophobic interface. We find that the adsorption free energy for PEG oligomers at a clean, planar water/alkane interface is around 1.3 kBT per monomer for the atomistic force field but is less than half of this for the two CG force fields. With the newly validated GROMOS 53a6OXY+D force field, we bracket the dilute adsorption free energy for a model Tween 80 molecule at the clean water/squalane interface. We also calculate the pressure-area isotherm. We exploit these data with the Nikas-Mulqueen-Blankschtein (NMB) theory and a simple transport model to demonstrate a transition from irreversible to reversible adsorption with increasing surface coverage, consistent with experimental results of Reichert and Walker [Langmuir 2013, 29 (6), 1857-1867].

Effect of Humidity on Electrical Conductivity of Pristine and Nanoparticle-Loaded Hydrogel Nanomembranes

We studied here the effect of humidity on the electrical conductivity of pristine and nanoparticle-loaded hydrogel nanomembranes. The membranes were fabricated by the thermally activated cross-linking of amine- and epoxy-terminated, star-branched poly(ethylene glycol) (PEG) oligomers. The resistance of the pristine membrane changed by ∼5.5 orders of magnitude upon relative humidity (RH) variation from 0% to 100%, which is an unprecedented response for homogeneous materials. The dependence of the resistance on the moisture uptake into the membrane could be coarsely described by an exponential function. The loading of the membranes with gold and silver nanoparticles (NPs) resulted in a noticeable improvement of their conductance at low RH but in a small improvement or even a negative effect on the conductance at high RH. Both pristine and NP-loaded PEG hydrogel membranes have significant potential as highly sensitive elements in humidity sensors and moisture-responsive nanoelectronic devices.

High-Resolution Size-Discrimination of Single Nonionic Synthetic Polymers with a Highly Charged Biological Nanopore.

Electrophysiological studies of the interaction of polymers with pores formed by bacterial toxins (1) provide a window on single molecule interaction with proteins in real time, (2) report on the behavior of macromolecules in confinement, and (3) enable label-free single molecule sensing. Using pores formed by the staphylococcal toxin α-hemolysin (aHL), a particularly pertinent observation was that, under high salt conditions (3-4 M KCl), the current through the pore is blocked for periods of hundreds of microseconds to milliseconds by poly(ethylene glycol) (PEG) oligomers (degree of polymerization approximately 10-60). Notably, this block showed monomeric sensitivity on the degree of polymerization of individual oligomers, allowing the construction of size or mass spectra from the residual current values. Here, we show that the current through the pore formed by aerolysin (AeL) from Aeromonas hydrophila is also blocked by PEG but with drastic differences in the voltage-dependence of the interaction. In contrast to aHL, AeL strongly binds PEG at high transmembrane voltages. This fact, which is likely related to AeL's highly charged pore wall, allows discrimination of polymer sizes with particularly high resolution. Multiple applications are now conceivable with this pore to screen various nonionic or charged polymers.

Effect of ion-chelating chain lengths in thiophene-based monomers on in situ photoelectrochemical polymerization and photovoltaic performances.

We synthesized thiophene-based monomers (bis-EDOTs) with different ethylene glycol oligomer (EGO) lengths (TBO3, TBO4, and TBO5) and investigated their polymerization characteristics during photoelectrochemical polymerization (PEP) at the surfaces of dye (D205)-sensitized TiO2 nanocrystalline particles. During the PEP reaction, monomers were expected to diffuse toward neighboring dyes through the growing polymer layers to enable continuous chain growth. We found that the less bulky monomer (TBO3) formed a more compact polymer layer with a high molecular weight. Its diffusion to the active sites through the resulting growing polymer layer was, therefore, limited. We deployed layers of the polymers (PTBO3, PTBO4, and PTBO5) in iodine-free solid-state hybrid solar cells to investigate the lithium ion chelating properties of the polymers as a function of the number of oxygen atoms present in the EGOs. PTBO4 and PTBO5 were capable of chelating lithium ions, yielding a photovoltaic performance that was 142% of the performance obtained without the polymer layers (3.0→5.2%).

Development of a method of carbon sorbent modification with polyglicolic acid to create new carbon materials for medical application

The surface of the VNIITU-1 carbon mesoporous sorbent was modified with polyglicolic acid characterized by antibacterial and antifungal properties. Synthesis was carried out in three stages: 1) carbon sorbent impregnation with 50% aqueous glycolic acid solution for 8 h, 2) sorbent drying for 1 h at a temperature of 105 ± 2°C; 3) and thermal treatment of the carbon sorbent impregnated by glycolic acid during the first hour at a temperature of 195 ± 5°C with further heating for 5 h at the temperature of 225 ± 5°C. Carbon sorbent samples were studied using a complex of physico-chemical methods: scanning electron microscopy; IR spectroscopy; X-ray photoelectron spectroscopy; low-temperature adsorption of nitrogen; nuclear magnetic resonance; thermogravimetry; X-ray microanalysis; and C, H, S, O analysis. It is found that the modifier is strongly fixed in the carbon sorbent surface predominantly in the form of glycolic acid oligomers (hexamers). As a result of modification, the amount of oxygen-containing moieties increases considerably as compared to the initial sorbent. The synthesized samples are of great interest as materials for sorption medicine.

Designing crosslinked hyaluronic acid hydrogels with tunable mechanical properties for biomedical applications

ABSTRACTThis study develops a simple copolymerization/crosslinking technique to control the swelling and mechanical properties of hyaluronic acid‐based hydrogels. Because of the widespread acceptance of poly(ethylene glycol) in biomedical applications, functionalized oligomers of ethylene glycol (EG) were used as comonomers to crosslink methacrylated hyaluronic acid (MHA). The swelling degree, shear and elastic moduli, and fracture properties (stress and strain) of the gels were investigated as a function of the crosslinking oligomer length and reactive group(s). It was hypothesized that acrylated oligomers would increase the crosslink density of the gels through formation of kinetic chains by reducing the steric hindrances that otherwise may limit efficient crosslinking of hyaluronic acid into gels. Specifically, after crosslinking 13 wt % MHA (47% degree of methacrylation) with 0.06 mol % of (EG)n‐diacrylate, the swelling ratio of the MHA gel decreased from 27 to 15 g/g and the shear modulus increased from 140 to 270 kPa as n increased from 1 to 13 units. The length and functionality (i.e., acrylate vs. methacrylate) of the oligomer controlled the crosslink density of the gels. The significant changes in the gel properties obtained with the addition of low levels of the PEG comonomer show that this method allows precise tuning of the physical properties of hyaluronic acid (HA) gels to achieve desired target values for biomedical applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42009.