Constituent Monomers Research Articles

The discovery of a lactone isomerase involved in pectin degradation (LB137)

Pectin, an abundant plant cell wall polymer, is being investigated as a possible raw material for the production of fuel and chemical products. To this end, an understanding of the steps to degrade pectin is useful. Agrobacterium tumefaciens strain C58 can use the primary constituent monomer of pectin, D‐galacturonate, as a sole carbon source and converts it to α‐ketoglutarate through a five step pathway in which the first step is oxidation of D‐galacturonate to D‐galactaro‐1,5‐lactone. We became interested in this pathway because a member of the functionally diverse enolase superfamily, designated Gci, catalyzes the third step in the pathway, and our lab has studied the enolase superfamily for over 20 years. We have identified an enzyme, D‐galactarolactone isomerase (GLI), adjacent to Gci in Agrobacterium’s genome, that catalyzes the second step in the pathway: the isomerization of D‐galactaro‐1,5‐lactone to D‐galactaro‐1,4‐lactone. The uncatalyzed isomerization reaction is “fast” and had been presumed to occur without the need of a catalyst. To characterize the enzyme‐catalyzed isomerization, we used 1H NMR to identify the activity, polarimetry to determine the kinetic constants (kcat = 440 s‐1, kcat/Km = 8.3 x 104 M‐1 s‐1, rate enhancement = 6.8 x 105), x‐ray crystallography to determine its structure, and gene expression analysis to connect the in vitro activity of the enzyme to an in vivo function. GLI is a member of the functionally diverse amidohydrolase superfamily and a homologue of LigI that catalyzes the hydrolysis of 2‐pyrone‐4,6‐dicarboxylate in lignin degradation. GLI’s ability to catalyze lactone isomerization instead of hydrolysis can be explained by the absence of the general basic catalysis used by LigI. This work identified the first example of lactone isomerization in the amidohydrolase superfamily and a missing enzyme in Agrobacterium’s pathway to catabolize pectin.Grant Funding Source: Supported by National Institutes of Health Grants P01GM071790 and U54GM093342 to J.A.G.

Molecular Perspectives for mu/delta Opioid Receptor Heteromers as Distinct, Functional Receptors

Opioid receptors are the sites of action for morphine and the other opioid drugs. Abundant evidence now demonstrates that different opioid receptor types can physically associate to form heteromers. Understandings of the nature, behavior, and role of these opioid receptor heteromers are developing. Owing to their constituent monomers’ involvement in analgesia, mu/delta opioid receptor (M/DOR) heteromers have been a particular focus of attention. There is now considerable evidence demonstrating M/DOR to be an extant and physiologically relevant receptor species. Participating in the cellular environment as a distinct receptor type, M/DOR availability is complexly regulated and M/DOR exhibits unique pharmacology from that of other opioid receptors (ORs), including its constituents. M/DOR appears to have a range of actions that vary in a ligand- (or ligands-) dependent manner. These actions can meaningfully affect the clinical effects of opioid drugs: strategies targeting M/DOR may be therapeutically useful. This review presents and discusses developments in these understandings with a focus on the molecular nature and activity of M/DOR in the context of therapeutic potentials.

Transport and retention of aqueous dispersions of superparamagnetic nanoparticles in sandstone

We evaluate the transport of surface-treated superparamagnetic iron-oxide nanoparticles in Boise-sandstone rocks by injecting aqueous dispersions of the particles into core plugs. Several different surface treatments yield stable dispersions of these particles, but provide very different transport characteristics. Effluent concentration histories are measured to obtain the particle retention in the rock. The results are used to optimize the particle surface coating so that the reservoir application requirements for the functional nanoparticles can be achieved. The application of interest here requires the nanoparticles to adsorb to oil/water interfaces.Our earlier experiments (Yu et al., 2010) showed that the paramagnetic nanoparticles stabilized with small negatively-charged citrate ligands have little retention in sedimentary rocks, but their preferred adsorption at the oil/water interfaces in rock pores was not achieved. A major improvement in surface coating optimization is achieved by creating a crosslinked polymer film that wraps around the nanoparticle so that it does not detach from the particle surface even under the harsh reservoir conditions. To fine-tune the coating to satisfy the reservoir application requirements, co-polymers and ter-polymers with different constituent monomers are employed. Nanoparticles stabilized with (poly-styrene sulfonate–alt-maleic acid) coating show a good adsorption tendency at the oil/water interfaces, while with very low adsorption at rock surface (~0.02mg/m2). The dispersion also has long-term stability even at high salinity (8wt% NaCl). Other polymers, such as (polyacrylic acid–r-butyl acrylate), (polyacrylic acid–b-styrene sulfonic acid), and (polyacrylic acid–r-butyl acrylate–b-styrene sulfonic acid), were also tested. The coating with the last polymer (PAA–PBA–PSS) provides a very low retention of particles in the rock, but only marginal preferred adsorption at oil/water interfaces.

Amphiphilic N-methylimidazole-functionalized diblock copolythiophenes

Amphiphilic diblock copolythiophenes are synthesized by an efficient two-step synthetic strategy. The block architecture is created via the quasi-living Grignard metathesis reaction, after which ionic imidazolium moieties are introduced by substitution on the bromohexyl side chains of one of the monomer constituents. The compositional influence on the solution behavior and thermal properties of both the precursor and ionic block copolythiophenes is investigated. The novel materials are of particular appeal for integration in organic solar cell stacks, either as active layer or interlayer materials.

Sequential Domain Realignment Driven by Conformational Asymmetry in Block Copolymer Thin Films

In this contribution, we use dissipative particle dynamics simulations to investigate the orientations of lamella-forming copolymers with two blocks of equal molecular weight confined in thin films. We employ neutral and symmetric interactions between the copolymer blocks and the walls, a situation for which contradicting observations have been made in experiments and previous theoretical studies. Our model takes into account a realistic degree of conformational asymmetry between the blocks, which stems from unequal Kuhn lengths of the constituent monomers. We perform a thorough scaling analysis to exclude finite size effects, and find, in agreement with experiments, a remarkable cascade of morphological transitions from parallel to perpendicular orientations when the film height is varied. We demonstrate that the emergence of a stable parallel configuration stems from entropic effects due to the conformational asymmetry and the confinement of the system.

Concerted halogen bonding and orthogonal metal-halogen interactions in dimers of lithium formamidinate and halogenated formamidines: an ab initio study.

Dimers of lithium formamidinate, CH(NH)2Li, and halogenated formamidines, HN=CHNHX, (X=Cl, Br, or I) are used as model systems to investigate simultaneous N-X···N and N-Li···N interactions, in tandem with orthogonal Li···X interactions. Geometry optimizations and energy calculations for the dimers are examined with the MP2 method and the M06-2X hybrid functional and the aug-cc-pVTZ basis set (the aug-cc-pVTZ-PP basis set is used for the iodine atom). Both methods predict the formation of a planar structure of C2v symmetry, regardless of the identity of the halogen atom. In this structure, the identities of the constituent monomers are essentially lost. Accordingly, the N-X···N interactions emerge as a rather symmetric quasi-linear N···X···N, where the covalent N-X bond in the halogenated formamidine is replaced by a partly covalent N···X interaction. Formation of the C2v structure is also driven by a fairly linear N···Li···N interaction parallel to the N···X···N interaction, and a Li···X interaction orthogonal to both the N···X···N and N···Li···N interactions. The strength of the interactions increases with the size of the halogen. The robustness of the interactions suggests that the dimers studied here or suitable analogues may find diverse applications including their use as novel polymeric synthons.

Functional Inositol 1,4,5-Trisphosphate Receptors Assembled from Concatenated Homo- and Heteromeric Subunits

Vertebrate genomes code for three subtypes of inositol 1,4,5-trisphosphate (IP3) receptors (IP3R1, -2, and -3). Individual IP3R monomers are assembled to form homo- and heterotetrameric channels that mediate Ca(2+) release from intracellular stores. IP3R subtypes are regulated differentially by IP3, Ca(2+), ATP, and various other cellular factors and events. IP3R subtypes are seldom expressed in isolation in individual cell types, and cells often express different complements of IP3R subtypes. When multiple subtypes of IP3R are co-expressed, the subunit composition of channels cannot be specifically defined. Thus, how the subunit composition of heterotetrameric IP3R channels contributes to shaping the spatio-temporal properties of IP3-mediated Ca(2+) signals has been difficult to evaluate. To address this question, we created concatenated IP3R linked by short flexible linkers. Dimeric constructs were expressed in DT40-3KO cells, an IP3R null cell line. The dimeric proteins were localized to membranes, ran as intact dimeric proteins on SDS-PAGE, and migrated as an ∼1100-kDa band on blue native gels exactly as wild type IP3R. Importantly, IP3R channels formed from concatenated dimers were fully functional as indicated by agonist-induced Ca(2+) release. Using single channel "on-nucleus" patch clamp, the channels assembled from homodimers were essentially indistinguishable from those formed by the wild type receptor. However, the activity of channels formed from concatenated IP3R1 and IP3R2 heterodimers was dominated by IP3R2 in terms of the characteristics of regulation by ATP. These studies provide the first insight into the regulation of heterotetrameric IP3R of defined composition. Importantly, the results indicate that the properties of these channels are not simply a blend of those of the constituent IP3R monomers.

Biosynthetic polyesters consisting of 2-hydroxyalkanoic acids: current challenges and unresolved questions

2-Hydroxyalkanoates (2HAs) have become the new monomeric constituents of bacterial polyhydroxyalkanoates (PHAs). PHAs containing 2HA monomers, lactate (LA), glycolate (GL), and 2-hydroxybutyrate (2HB) can be synthesized by engineered microbes in which the broad substrate specificities of PHA synthase and propionyl-CoA transferase are critical factors for the incorporation of the monomers into the polymer chain. LA-based polymers, such as P[LA-co-3-hydroxybutyrate (3HB)], have the properties of pliability and stretchiness which are distinctly different from those of the rigid poly(lactic acid) (PLA) and P(3HB) homopolymers. This versatile platform is also applicable to the biosynthesis of GL- and 2HB-based polymers. In the case of the synthesis of 2HB-based polymers, the enantiospecificity of PHA synthase enabled the production of isotactic (R)-2HB-based polymers, including P[(R)-2HB], from racemic precursors of 2HB. P(2HB) is a pliable material, in contrast to PLA. Furthermore, to obtain a new 2HA-polymerizing PHA synthase, the class I PHA synthase from Ralstonia eutropha was engineered so as to achieve the first incorporation of LA units. The analysis of the polymer synthesized using this new LA-polymerizing PHA synthase unexpectedly focused a spotlight on the studies on block copolymer biosynthesis.

Phytochemical Profiles of Black, Red, Brown, and White Rice from the Camargue Region of France

Secondary metabolites in black, red, brown, and white rice grown in the Camargue region of France were investigated using HPLC-PDA-MS(2). The main compounds in black rice were anthocyanins (3.5 mg/g), with cyanidin 3-O-glucoside and peonidin 3-O-glucoside predominating, followed by flavones and flavonols (0.5 mg/g) and flavan-3-ols (0.3 mg/g), which comprised monomeric and oligomeric constituents. Significant quantities of γ-oryzanols, including 24-methylenecycloartenol, campesterol, cycloartenol, and β-sitosterol ferulates, were also detected along with lower levels of carotenoids (6.5 μg/g). Red rice was characterized by a high amount of oligomeric procyanidins (0.2 mg/g), which accounted >60% of secondary metabolite content with carotenoids and γ-oryzanol comprising 26.7%, whereas flavones, flavonols and anthocyanins were <9%. Brown and white rice contained lower quantities of phytochemicals, in the form of flavones/flavonols (21-24 μg/g) and γ-oryzanol (12.3-8.2 μg/g), together with trace levels of the carotenoids lutein and zeaxanthin. Neither anthocyanins nor procyanidins were detected in brown and white rice. By describing the profile of the heterogeneous mixture of phytochemicals present in different rice varieties, this study provides a basis for defining the potential health effects related to pigmented and nonpigmented rice consumption by humans.

Coherent backscattering by discrete random media composed of clusters of spherical particles

The approximate method of accounting for the weak localization effect in discrete random media makes it possible to calculate the intensity and the degree of linear polarization of radiation reflected by a semi-infinite layer containing randomly oriented clusters of identical nonabsorbing spherical particles. The paper is focused on the analysis of the influence of the medium properties – the concentration of the clusters, their structure, the sizes and the number of constituent monomers – on the phase dependence of the characteristics of the interference (coherent) component of radiation. Three types of clusters were chosen for the analysis: a fractal-like cluster and two random clusters with different packing densities of monomers. Three values of the size parameters of monomers were considered: 0.5, 1.0, and 1.5. The chosen values of the refractive index of monomers correspond to that of magnesium oxide in the visible spectral range. This allowed us to compare the theoretical phase curves of the degree of linear polarization of light reflected by the medium with the data of measurements by Lyot. For all of the considered cluster types, starting from some minimal number of constituent monomers, which is typical of the specified cluster's type and the monomer's size, the characteristics of the coherent component were found to be practically independent of the number of constituents. In particular, in the phase-angle range from 0° to 15°, the branch of negative polarization measured for a layer of magnesium oxide by Lyot can be well described with several models of the media containing either the fractal-like clusters or the random clusters with the packing density larger than 30%. In these models, the number and sizes of constituent monomers vary. To select from the whole set of “suitable” clusters those the optical characteristics of which actually correspond to characteristics of an elementary volume of the specified medium, additional information is required. For example, this can be the results of polarization measurements in a wider phase interval that includes a zone of the dominating influence of incoherent (diffuse) scattering.

Excitation Energy Transfer and Quenching in a Heterodimer: Applications to the Carotenoid–Phthalocyanine Dyads

The dynamics of a molecular heterodimer composed of a long-lived excitation donor and a short-lived acceptor (quencher) is examined. In order to consider various dynamical regimes without any restrictions on the system parameters, the energy transfer is modeled employing the hierarchical equations of motion, while the relaxation to the ground state is treated by assuming a phenomenological spontaneous nonradiative decay rate. Time scales of the resulting two-exponential evolution are investigated as functions of the energy gap and the resonance coupling between the monomeric constituents of the dimer. Relevance of the present analysis to the recent experimental findings on artificial carotenoid-phthalocyanine dyads is discussed. By examining the first two time scales of the reported time-resolved spectra, it is shown that upon the increase of carotenoid conjugation length its first excited state approaches the first excited state of phthalocyanine from above, thereby inducing a remarkable quenching. The proposed model also provides a unified treatment of quenching in the regimes previously distinguished as energy transfer and excitonic state formation.

Formation of Cyclic and Polymeric Structures from Zwitterions

Covalent linkages: Zwitterion-based covalent linkages were observed in cyclic oligomers and in dispersed polymers based on monomers. Addition of acids and bases promoted transitions between monomeric species and the oligomeric and/or polymeric states. Exchange of constituent monomer units in the cyclic oligomers was observed in the solution state, whereas the polymers obtained as precipitates from CH3CN were not converted to the cyclic oligomers (see scheme).

Many-Body Expansion with Overlapping Fragments: Analysis of Two Approaches.

The traditional many-body expansion-in which a system's energy is expressed in terms of the energies of its constituent monomers, dimers, trimers, etc.-has recently been generalized to the case where the "monomers" (subsystems, or "fragments") overlap. Two such generalizations have been proposed, and here, we compare the two, both formally and numerically. We conclude that the two approaches are distinct, although in many cases they yield comparable and accurate results when truncated at the level of dimers. However, tests on fluoride-water clusters suggest that the approach that we have previously called the "generalized many-body expansion" (GMBE) [J. Chem. Phys.137, 064113 (2012)] is more robust, with respect to the choice of fragments, as compared to an alternative "many overlapping body expansion" [J. Chem. Theory Comput.8, 2669 (2012)]. A more detailed justification for the GMBE is also provided here.

Binding Kinetics and Affinities of Heterodimeric versus Homodimeric HIV-1 Reverse Transcriptase on DNA–DNA Substrates at the Single-Molecule Level

During viral replication, HIV-1 reverse transcriptase (RT) plays a pivotal role in converting genomic RNA into proviral DNA. While the biologically relevant form of RT is the p66-p51 heterodimer, two recombinant homodimer forms of RT, p66-p66 and p51-p51, are also catalytically active. Here we investigate the binding of the three RT isoforms to a fluorescently labeled 19/50-nucleotide primer/template DNA duplex by exploiting single-molecule protein-induced fluorescence enhancement (SM-PIFE). PIFE, which does not require labeling of the protein, allows us to directly visualize the binding/unbinding of RT to a double-stranded DNA substrate. We provide values for the association and dissociation rate constants of the RT homodimers p66-p66 and p51-p51 with a double-stranded DNA substrate and compare those to the values recorded for the RT heterodimer p66-p51. We also report values for the equilibrium dissociation constant for the three isoforms. Our data reveal great similarities in the intrinsic binding affinities of p66-p51 and p66-p66, with characteristic Kd values in the nanomolar range, much smaller (50-100-fold) than that of p51-p51. Our data also show discrepancies in the association/dissociation dynamics among the three dimeric RT isoforms. Our results further show that the apparent binding affinity of p51-p51 for its DNA substrate is to a great extent time-dependent when compared to that of p66-p66 and p66-p51, and is more likely determined by the dimer dissociation into its constituent monomers rather than the intrinsic binding affinity of dimeric RT.

Sporopollenin monomer biosynthesis in arabidopsis

Land plants have evolved aliphatic biopolymers that protect their cell surfaces against dehydration, pathogens, and chemical and physical damage. In flowering plants, a critical event during pollen maturation is the formation of the pollen surface structure. The pollen wall consists essentially of the microspore-derived intine and the sporophyte-derived exine. The major component of the exine is termed sporopollenin, a complex biopolymer. The chemical composition of sporopollenin remains poorlycharacterized because it is extremely resistant to chemical and biological degradation procedures. Recent characterization of Arabidopsis thaliana genes and corresponding enzymes involved in exine formation has demonstrated that the sporopollenin polymer consists of phenolic and fatty acid-derived constituents that are covalently coupled by ether and ester linkages. This review illuminates the outlines of a biosynthetic pathway involved in generating monomer constituents of the sporopollenin biopolymer component of the pollen wall.

Thermo-responsive discotic nematic hydrogels

We synthesized a novel thermo-responsive discotic nematic hydrogel. This liquid crystalline polymer nanocomposite was fabricated using extremely high-aspect-ratio (ξ = diameter/thickness ∼ 103) zirconium phosphate (ZrP) nano-sheets embedded into a polymeric network. These nano-sheets were immersed into a solution of constituent monomers of N-isopropylacrylamide (NIPAm) and acrylamide (AAm) with a subsequent polymerization in situ to obtain a hydrogel embedded with the nematic liquid crystal of the nano-sheets. We analyzed the effect of initiator (APS) and catalyst (TEMED) concentration on the nematic domains at ZrP nano-sheet volume fractions (ϕZrP) near the isotropic–nematic (I–N) transition. The mixing during hydrogel preparation allowed the aligning of the nano-sheets into highly ordered domains, which were eventually disturbed by the effect of APS and TEMED on the polymer matrix. The effect of ZrP nano-sheet concentration and temperature on the nematic hydrogels was also studied. By increasing the temperature above the LCST of PNIPAm, the hydrogels entered into a hydrophilic-to-hydrophobic transition. Interestingly, hydrogels containing ZrP nano-sheets presented increased hydrogel water retention. In addition, we observed that the variation of the nematic ordering (S2) and ϕZrP within the system manipulated the birefringent color patterns of the hydrogels. Finally, a nematic hydrogel placed into a thin-rectangular capillary from 298 K to 333 K presented edge-wrinkling. An isotropic-to-nematic transition guided by the increment in the ZrP nano-sheet nematic ordering was observed at a nano-sheet concentration slightly below the isotropic concentration (ϕI).

Effect of experimental photopolymerized coatings on the hydrophobicity of a denture base acrylic resin and on Candida albicans adhesion

ObjectiveThis study investigated the effect of experimental photopolymerized coatings, containing zwitterionic or hydrophilic monomers, on the hydrophobicity of a denture base acrylic resin and on Candida albicans adhesion. MethodsAcrylic specimens were prepared with rough and smooth surfaces and were either left untreated (control) or coated with one of the following experimental coatings: 2-hydroxyethyl methacrylate (HE); 3-hydroxypropyl methacrylate (HP); and 2-trimethylammonium ethyl methacrylate chloride (T); and sulfobetaine methacrylate (S). The concentrations of these constituent monomers were 25%, 30% or 35%. Half of the specimens in each group (control and experimentals) were coated with saliva and the other half remained uncoated. The surface free energy of all specimens was measured, regardless of the experimental condition. C. albicans adhesion was evaluated for all specimens, both saliva conditioned and unconditioned. The adhesion test was performed by incubating specimens in C. albicans suspensions (1×107cell/mL) at 37°C for 90min. The number of adhered yeasts were evaluated by XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-5-[{phenylamino}carbonyl]-2H-tetrazolium-hydroxide) method. ResultsFor rough surfaces, coatings S (30 or 35%) and HP (30%) resulted in lower absorbance values compared to control. These coatings exhibited more hydrophilic surfaces than the control group. Roughness increased the adhesion only in the control group, and saliva did not influence the adhesion. The photoelectron spectroscopy analysis (XPS) confirmed the chemical changes of the experimental specimens, particularly for HP and S coatings. ConclusionsS and HP coatings reduced significantly the adhesion of C. albicans to the acrylic resin and could be considered as a potential preventive treatment for denture stomatitis.

Lactose Repressor Experimental Folding Landscape: Fundamental Functional Unit and Tetramer Folding Mechanisms

The fundamental principles that govern monomer folding are believed to be congruent with those of protein oligomers. However, the effects of protein assembly during the folding reaction can result in a series of complex transitions that are considerably more challenging to deconvolute. Here we developed the experimental protein folding mechanism for the lactose repressor (LacI), for both the dimeric and the tetrameric states, using equilibrium unfolding and kinetic experiments, and by leveraging the previously reported monomer folding landscape. Reaction details for LacI oligomers were observed by way of circular dichroism, intrinsic fluorescence, and Förster resonance energy transfer (FRET) and as a function of protein concentration. In general, the dimer and tetramer are four-phase folding reactions in which the first three transitions are tantamount to the folding of constituent monomers. The final reaction phase of the LacI dimer can be attributed to protein assembly, based on the concentration dependence of the observed folding rates and intermolecular FRET measurements. Unlike the dimer, the latter reaction phase of the LacI tetramer is not dependent on protein concentration, likely because of a strong tethering of the monomers, which simplifies the folding reaction by eliminating an explicit protein assembly phase. Finally, folding of the LacI dimer and tetramer was assessed in the presence of polyethylene glycol to rule out inert molecular crowding as the driving force for the protein folding reaction; in addition, these data provide insight into the folding mechanism in vivo.

Magnetism in Thiolated Gold Model Junctions

Three stable, neutral diradical model molecules with an even number of electrons, based on pairs of small thiolated Au clusters connected via Au–Au bonding, are studied within a broken symmetry unrestricted density functional theory involving a set of exchange-correlation functionals, including PBE, M06L, TPSS, B3LYP, M06, and TPSSh. The models, mostly with an antiferromagnetic ground state within the theory used, are analyzed in terms of the vertical spin–flip energy splitting, total spin expectation values, Heisenberg exchange coupling constant, magnetic orbitals and their overlap, diradical character, binding energies, natural bond-order analysis, and bond index of the central Au–Au bond. The spin-symmetry breaking is attributed to the open-shell nature of the dimerized monomer constituents and the structural feature of the facing S–Au–S edges, in combination with the attractive unsupported metallophilic d–d interaction of the incident Au atoms, allowing a weak coupling of the spins localized sideways. The modeling provides insight to AuI–AuI interactions, potentially useful in design of novel gold-based magnetic nanoscopic assemblies.

Candida albicans adherence to an acrylic resin modified by experimental photopolymerised coatings: an in vitro study

This study evaluated whether photopolymerised coatings containing zwitterion or hydrophilic monomers would reduce the adhesion of Candida albicans to an acrylic resin. Disc-shaped samples (n=468) were fabricated with rough or smooth surfaces. The samples did not receive any surface treatment (control) or were coated with one of the following experimental coatings (2-hydroxyethyl methacrylate - HE; 3-hydroxypropyl methacrylate - HP; and 2-trimethylammonium ethyl methacrylate chloride - T; and sulfobetaine methacrylate - S). The concentrations of the constituent monomers were 25, 30 or 35%. The water contact angles of the samples were measured, and half of the samples were exposed to saliva. The adherent yeast cells were counted after crystal violet staining. For the smooth samples, the groups S35, HP35 and HE35 showed significantly lower number of adhered Candida than control, in the absence of saliva. There were no significant differences among the experimental and control groups for the rough samples, but the saliva decreased the cell numbers for groups S25, S30 and HP30. The photoelectron spectroscopy analysis confirmed the changes in the chemical compositions of the experimental samples. The experimental photopolymerised coatings changed the chemical composition and decreased C.albicans adhesion in the groups S35, HP35 and HE35, suggesting that they should be further investigated.