Maximum Incorporation Research Articles

Enzymatic grafting of gallate ester onto chitosan: evaluation of antioxidant and antibacterial activities

SummaryThe antioxidant octyl gallate (OG) has been successfully grafted onto chitosan by means of horseradish peroxidase biocatalyst. The maximum gallate incorporation onto chitosan determined by 1H NMR spectroscopy was up to 16 molar%. The resulting materials displayed antioxidant capacities with DPPH radical inhibition percentage up to 23% upon the assay conditions. The grafting of the antioxidant on chitosan enhanced its antimicrobial activity. Minimal inhibitory concentration (MIC) for Escherichia coli was 0.5 g L−1. The native medium molecular weight chitosan alone or grafted with the lowest OG incorporation (ca. 11 molar%) attained 100% inhibition of E. coli, whereas lower inhibition was observed for all other materials 50.7–68.9% corresponding a reduction in the counts from 10.6 to 5.23–3.30 Log CFU mL−1. The inhibition of Listeria monocytogenes was significantly higher (59.8–100%) than that with the Gram negative bacterium reaching the MIC at 0.25 g L−1 with a reduction in the counts from 12.6 Log CFU mL−1 to 5.06–0 Log CFU mL−1.

Construction and analysis of a genetically tuneable lytic phage display system

The Bacteriophage λ capsid protein gpD has been used extensively for fusion polypeptides that can be expressed from plasmids in Escherichia coli and remain soluble. In this study, a genetically controlled dual expression system for the display of enhanced green fluorescent protein (eGFP) was developed and characterized. Wild-type D protein (gpD) expression is encoded by λ Dam15 infecting phage particles, which can only produce a functional gpD protein when translated in amber suppressor strains of E. coli in the absence of complementing gpD from a plasmid. However, the isogenic suppressors vary dramatically in their ability to restore functional packaging to λDam15, imparting the first dimension of decorative control. In combination, the D-fusion protein, gpD::eGFP, was supplied in trans from a multicopy temperature-inducible expression plasmid, influencing D::eGFP expression and hence the availability of gpD::eGFP to complement for the Dam15 mutation and decorate viable phage progeny. Despite being the worst suppressor, maximal incorporation of gpD::eGFP into the λDam15 phage capsid was imparted by the SupD strain, conferring a gpDQ68S substitution, induced for plasmid expression of pD::eGFP. Differences in size, fluorescence and absolute protein decoration between phage preparations could be achieved by varying the temperature of and the suppressor host carrying the pD::eGFP plasmid. The effective preparation with these two variables provides a simple means by which to manage fusion decoration on the surface of phage λ.

Influence of vegetable purees on quality attributes of pastas made from bread wheat (T. aestivum)

Various vegetable puree-incorporated quick cooking pastas (VPP) from non-durum wheat T. aestivum were developed and their quality attributes were evaluated. The results indicated that maximum incorporation of puree was used in carrot pasta (420 g/kg) and minimum amount was incorporated in beetroot pasta (150 g/kg). High yellowness was observed in carrot pasta (20.33) and low in the case of beetroot pasta (8.73). All VPP had lower cooking loss, swelling index and texture values than the control. Overall sensory scores of all the VPP was low as compared to the control except in the case of carrot pasta (6.1) which had a score comparable with the control (6.2). The pigment and crude fiber content were found to be higher in VPP. The scanning electron microscopy (SEM) analysis of the cooked pastas revealed that addition of purees have altered microstructure of pasta comprising starch granules and protein matrix network which contributed to the difference in the cooking loss.

Microporous Carbonaceous Materials Incorporated with Metal (Ti, V and Zn) for Hydrogen Storage

The present research work is focused on the development and characterization of light weight microporous carbonaceous material, such as graphite (53150 micron) incorporated with either titanium n-butoxide, titanium diisopropoxide bis (2,4-pentanedionate), vanadium 2,4-pentane-dionate or zinc 2,4-pentanedionate having varying wt% of the metal (28%) using 2-propanol/ethanol as solvent at 4050 °C. The calcination has been carried out at 100, 150 and 200 °C, except the samples with titanium diisopropoxide bis (2,4-pentanedionate) which are calcined at 80 °C. FESEM along with atomic absorption studies revealed that the maximum incorporation of metals (Zn, V and Ti) in graphite has been observed with 4 wt% of zinc 2,4-pentanedionate calcined at 100 °C, 4 wt% of vanadium 2,4-pentanedionate calcined at 100 °C, 4 wt% of titanium n-butoxide calcined at 100 °C and 2 wt% of titanium diisopropoxide bis (2,4-pentanedionate) calcined at 80 °C, and equilibration time of 20-24 h has been used in each case. These samples may be used for hydrogen storage.

Diurnal and light regulation of sulphur assimilation and glucosinolate biosynthesis in Arabidopsis

Glucosinolates are a major class of sulphur-containing secondary metabolites involved in plant defence against pathogens. Recently many regulatory links between glucosinolate biosynthesis and sulphate assimilation were established. Since sulphate assimilation undergoes diurnal rhythm and is light regulated, this study analysed whether the same is true for glucosinolate biosynthesis. The levels of glucosinolates and glutathione were found to be higher during the day than during the night. This agreed with variation in sulphate uptake as well as activity of the key enzyme of the sulphate assimilation pathway, adenosine 5’-phosphosulphate reductase. Correspondingly, the flux through sulphate assimilation was higher during the day than during the night, with the maximum flux through primary assimilation preceding maximal incorporation into glucosinolates. Prolonged darkness resulted in a strong reduction in glucosinolate content. Re-illumination of such dark-adapted plants induced accumulation of mRNA for many genes of glucosinolate biosynthesis, leading to increased glucosinolate biosynthesis. The light regulation of the glucosinolate synthesis genes as well as many genes of primary sulphate assimilation was controlled at least partly by the LONG HYPOCOTYL5 (HY5) transcription regulator. Thus, glucosinolate biosynthesis is highly co-regulated with sulphate assimilation.

Structural, Morphological, Optical and Electrical Properties of Zn<sub>(1-x)</sub>Cd<sub>x</sub>O Solid Solution Grown on <i>a</i>- and <i>r</i>-Plane Sapphire Substrate by MOCV

Zn(1-x)CdxO films have been grown on (a-plane) and (r-plane) sapphire substrate by metal organic chemical vapor deposition. A maximum cadmium incorporation of 8.5% and 11.2% has been respectively determined for films deposited on a- and r-plane sapphire. The optical transmission spectra and energy band-gap equation established by Makino et al. were used to estimate the cadmium mole fraction of the solid solutions. Structural, morphological and optical properties of these films were examined using high resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM) and room and low temperature photoluminescence (Pl) as Cd incorporation and employed substrate. X-ray diffraction study revealed that all films had wurtzite phase but solid solution grown on a-plane sapphire are polycrystalline with a preferred orientation along the [0001] direction and a-plane film are epitaxially grown on r-plane sapphire. AFM image show significant differences between morphologies depending on orientation sapphire substrate but no significant differences on surface roughness have been found. The near band-edge photoluminescence emission shifts gradually to lower energies as Cd is incorporated and reaches 2.916 eV for the highest Cd content (11.2%) at low temperature (20 K). The room temperature hall mobility decreases with the Cd incorporation but it is larger for Zn(1-x)CdxO grown on r-plane sapphire.

Subunit-specific Incorporation Efficiency and Kinetics in Mitochondrial Complex I Homeostasis

Studies employing native PAGE suggest that most nDNA-encoded CI subunits form subassemblies before assembling into holo-CI. In addition, in vitro evidence suggests that some subunits can directly exchange in holo-CI. Presently, data on the kinetics of these two incorporation modes for individual CI subunits during CI maintenance are sparse. Here, we used inducible HEK293 cell lines stably expressing AcGFP1-tagged CI subunits and quantified the amount of tagged subunit in mitoplasts and holo-CI by non-native and native PAGE, respectively, to determine their CI incorporation efficiency. Analysis of time courses of induction revealed three subunit-specific patterns. A first pattern, represented by NDUFS1, showed overlapping time courses, indicating that imported subunits predominantly incorporate into holo-CI. A second pattern, represented by NDUFV1, consisted of parallel time courses, which were, however, not quantitatively overlapping, suggesting that imported subunits incorporate at similar rates into holo-CI and CI assembly intermediates. The third pattern, represented by NDUFS3 and NDUFA2, revealed a delayed incorporation into holo-CI, suggesting their prior appearance in CI assembly intermediates and/or as free monomers. Our analysis showed the same maximum incorporation into holo-CI for NDUFV1, NDUFV2, NDUFS1, NDUFS3, NDUFS4, NDUFA2, and NDUFA12 with nearly complete loss of endogenous subunit at 24 h of induction, indicative of an equimolar stoichiometry and unexpectedly rapid turnover. In conclusion, the results presented demonstrate that newly formed nDNA-encoded CI subunits rapidly incorporate into holo-CI in a subunit-specific manner.

Phosphatidylcholine enrichment with medium chain fatty acids by immobilized phospholipase A1‐catalyzed acidolysis

Phospholipids are a biologically and industrially important class of compounds whose physical properties can be improved for diverse applications by substitution of medium-chain fatty acids for their native fatty acid chains. In this study, phosphatidylcholine (PC) was enriched with medium-chain fatty acids (MCFAs) by acidolysis with phospholipase A(1) (PLA(1) ) immobilized on Duolite A568. Response surface methodology was employed to evaluate the effects of the molar ratio of substrates (PC to free MCFAs), enzyme loading, and reaction temperature on the incorporation of free MCFAs into PC and on PC recovery. Enzyme loading and molar ratio of substrates contributed positively, but temperature negatively, to the incorporation of free MCFAs into PC. Increases in enzyme loading and the molar ratio of PC to free MCFAs led to increased incorporation of the latter into the former, but increased temperature had the opposite effect. By contrast, an increase in enzyme loading led to decreased PC recovery. Increased temperature had also a negative effect on PC recovery. Optimal conditions for maximum incorporation and PC recovery were molar ratio of PC to free MCFAs of 1:16, enzyme loading of 16%, and 50°C. Under these conditions, the incorporation of free MCFAs was 41% and the PC recovery was 53%.

Electrochemical growth of CoPt nanowires of different aspect ratio and their magnetic properties

The electrodeposition process of the CoPt system into two types of gold-coated polycarbonate and alumina membranes have been studied to test the possibility of electrochemical growth of CoPt nanowires with different length and aspect ratio but fixed composition showing hcp phase with maximum Pt incorporation. The evolution of the nanowires as a function of the deposition time was analysed; nanowires from 250nm to 8μm have been prepared. During the initial stages of the deposition, the formation of nanotubes in the membranes of higher porous diameter was observed, subsequently forming nanowires after continued deposition. With around 60wt.% of Pt the CoPt nanowires show distorted hcp cobalt phase and preferred orientation conditioned by the pore’s diameter of the membrane. When using polycarbonate membranes, nanowires with an aspect ratio of 0.025 or lower showed clear magnetic anisotropy and the membrane magnetises easily by applying a parallel magnetic field (magnetic field perpendicular to the nanowires axis). When the length of the nanowires was reduced, magnetic anisotropy decreased. Coercivity remains in the range between 500 and 1000Oe. When using an alumina template, the arrays showed similar coercivity, however, a higher magnetic anisotropy was observed with respect to those of similar length in a polycarbonate membrane, probably as a consequence of the elevated density of the arrays that permits higher interaction between the wires.

Nuclear transport receptor binding avidity triggers a self-healing collapse transition in FG-nucleoporin molecular brushes

Conformational changes at supramolecular interfaces are fundamentally coupled to binding activity, yet it remains a challenge to probe this relationship directly. Within the nuclear pore complex, this underlies how transport receptors known as karyopherins proceed through a tethered layer of intrinsically disordered nucleoporin domains containing Phe-Gly (FG)-rich repeats (FG domains) that otherwise hinder passive transport. Here, we use nonspecific proteins (i.e., BSA) as innate molecular probes to explore FG domain conformational changes by surface plasmon resonance. This mathematically diminishes the surface plasmon resonance refractive index constraint, thereby providing the means to acquire and correlate height changes in a surface-tethered FG domain layer to Kap binding affinities in situ with respect to their relative spatial arrangements. Stepwise measurements show that FG domain collapse is caused by karyopherin β1 (Kapβ1) binding at low concentrations, but this gradually transitions into a reextension at higher Kapβ1 concentrations. This ability to self-heal is intimately coupled to Kapβ1-FG binding avidity that promotes the maximal incorporation of Kapβ1 into the FG domain layer. Further increasing Kapβ1 to physiological concentrations leads to a "pileup" of Kapβ1 molecules that bind weakly to unoccupied FG repeats at the top of the layer. Therefore, binding avidity does not hinder fast transport per se. Revealing the biophysical basis underlying the form-function relationship of Kapβ1-FG domain behavior results in a convergent picture in which transport and mechanistic aspects of nuclear pore complex functionality are reconciled.

Incorporation of eicosapentaenoic and docosahexaenoic acids into lipid pools when given as supplements providing doses equivalent to typical intakes of oily fish

Background: Estimation of the intake of oily fish at a population level is difficult. The measurement of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in biological samples may provide a useful biomarker of intake.Objective: We identified the most appropriate biomarkers for the assessment of habitual oily fish intake and changes in intake by elucidating the dose- and time-dependent response of EPA and DHA incorporation into various biological samples that represent roles in fatty acid transport, function, and storage.Design: This was a double-blind, randomized, controlled intervention trial in 204 men and women that lasted 12 mo. EPA and DHA capsules were provided in a manner to reflect sporadic consumption of oily fish (ie, 1, 2, or 4 times/wk). EPA and DHA were assessed at 9 time points over 12 mo in 9 sample types (red blood cells, mononuclear cells, platelets, buccal cells, adipose tissue, plasma phosphatidylcholine, triglycerides, cholesteryl esters, and nonesterified fatty acids).Results: A dose response (P < 0.05) was observed for EPA and DHA in all pools except for red blood cell EPA (P = 0.057). EPA and DHA measures in plasma phosphatidylcholine and platelets were best for the discrimination between different intakes (P < 0.0001). The rate of incorporation varied between sample types, with the time to maximal incorporation ranging from days (plasma phosphatidylcholine) to months (mononuclear cells) to >12 mo (adipose tissue).Conclusions: Plasma phosphatidylcholine EPA plus DHA was identified as the most suitable biomarker of acute changes in EPA and DHA intake, and platelet and mononuclear cell EPA plus DHA were the most suitable biomarkers of habitual intake. This trial was registered at Current Controlled Trials (www.controlled-trials.com) as ISRCTN48398526.

Growth of (BGa)As, (BGa)P, (BGa)(AsP) and (BGaIn)P by MOVPE

The boron containing III/V-semiconductors (BGa)As, (BGa)P, (BGa)(AsP) and (BGaIn)P are grown by metal–organic-vapour-phase-epitaxy. The influence of growth conditions on maximum boron incorporation, boron incorporation efficiency and structural quality is investigated.A maximum boron concentration of 7.8% for (BGa)P and 9.9% for (BGa)(AsP) can be realized. Low growth temperature of 525°C and high V/III-ratios are needed to increase the maximum boron concentration and to improve the structural quality.A difference in boron incorporation efficiency and maximum boron concentration between (BGa)As and (BGa)P is observed. The TBAs/V ratio in the gas phase is identified as the factor determining the boron incorporation efficiency in (BGa)(AsP). (BGaIn)P samples with an indium concentration of 53% and a maximum boron concentration of 4% are realized.The possibility to achieve boron concentrations of several percent in III/V-semiconductors offers new perspectives for strain engineering in devices like multi-junction solar cells or semiconductor lasers.

Distribution of recently fixed photosynthate in a switchgrass plant-soil system

The use of switchgrass (Panicum virgatum L.) as an energy crop has gained great importance in past two decades due to its high biomass yields on marginal lands with low agricultural inputs and low maintenance requirements. Information on the allocation of photosynthetically fixed C in the switchgrass-soil system is important to understand the C flow and to quantify the sequestration of C in soils. The allocation of &lt;sup&gt;13&lt;/sup&gt;C labeled photosynthates in shoot, root, soil, and in microbial biomass carbon (MBC) of rhizosphere and bulk soil of 45 days old, greenhouse grown-switchgrass was examined during 20 days &lt;sup&gt;13&lt;/sup&gt;C-CO&lt;sub&gt;2&lt;/sub&gt; pulse labeling period. The total &lt;sup&gt;13&lt;/sup&gt;C recovered in the plant-soil system varied from 79% after 1 day to 42% after 20 days of labeling. After labeling, 54%, 40%, and 6% excess &lt;sup&gt;13&lt;/sup&gt;C resided in shoot, root and soil, respectively on day 1; 27%, 61% and 11%, respectively on day 5 and 20%, 63% and 17%, respectively day 20 after labeling. The maximum incorporation of &lt;sup&gt;13&lt;/sup&gt;C from roots into the MB of rhizosphere soil occurred within the first 24 h of labeling. The excess &lt;sup&gt;13&lt;/sup&gt;C values of rhizosphere soil and rhizosphere MBC were significantly higher than excess &lt;sup&gt;13&lt;/sup&gt;C values of bulk soil and the bulk soil MBC, respectively. The proportion of excess &lt;sup&gt;13&lt;/sup&gt;C in soil as MBC declined from 92 to 15% in rhizosphere soil and from 79 to 18% in bulk soil, for 1 day and 20 days after labeling, respectively. The present study showed the effectiveness of &lt;sup&gt;13&lt;/sup&gt;C labeling to examine the fate of recently photosynthesized C in soil-plant (switchgrass) system and dynamics of MBC. &amp;nbsp;

Effect of particle size and co-deposition technique on hardness and corrosion properties of Ni–Co/SiC composite coatings

Ni–Co/SiC alloy matrix composite coatings were electrodeposited in a modified Watt's bath containing micro and nano sized SiC particles by using conventional electro-co-deposition (CECD) and sediment co-deposition (SCD) techniques. The deposits were characterized using SEM, EDX and XRD analyses, and microhardness and potentiodynamic polarization measurements. The maximum incorporation of the SiC micro- and nano-particles was obtained using the SCD technique at deposition current densities of 2 and 3A/dm2, respectively. It was found that in the composite coatings, incorporation of SiC particles improves the microhardness of unalloyed Ni and Ni–Co alloy matrices. The nanocomposite coatings exhibit higher microhardness values than microcomposite ones. The potentiodynamic polarization measurements in 3.5% NaCl solution revealed that the corrosion resistance of the Ni–Co/SiC nanocomposite coatings is much higher than the Ni–Co alloy and Ni–Co/SiC microcomposite coatings. Moreover, corrosion resistance of Ni–Co/SiC nanocomposite coatings deposited by SCD technique is higher than the ones deposited by CECD technique. Corrosion resistance of the studied Ni–Co/SiC composite coatings was considerably affected by Co content, SiC particle size and content. Hardness enhancement was related to the structural features, and corrosion behavior was discussed based on the formation of corrosion micro cells, diminishing the effective metallic area, and increasing and hindering the corrosion paths.

Rapid incorporation kinetics and improved fidelity of a novel class of 3′-OH unblocked reversible terminators

Recent developments of unique nucleotide probes have expanded our understanding of DNA polymerase function, providing many benefits to techniques involving next-generation sequencing (NGS) technologies. The cyclic reversible termination (CRT) method depends on efficient base-selective incorporation of reversible terminators by DNA polymerases. Most terminators are designed with 3′-O-blocking groups but are incorporated with low efficiency and fidelity. We have developed a novel class of 3′-OH unblocked nucleotides, called Lightning Terminators™, which have a terminating 2-nitrobenzyl moiety attached to hydroxymethylated nucleobases. A key structural feature of this photocleavable group displays a ‘molecular tuning’ effect with respect to single-base termination and improved nucleotide fidelity. Using Therminator™ DNA polymerase, we demonstrate that these 3′-OH unblocked terminators exhibit superior enzymatic performance compared to two other reversible terminators, 3′-O-amino-TTP and 3′-O-azidomethyl-TTP. Lightning Terminators™ show maximum incorporation rates (kpol) that range from 35 to 45 nt/s, comparable to the fastest NGS chemistries, yet with catalytic efficiencies (kpol/KD) comparable to natural nucleotides. Pre-steady-state kinetic studies of thymidine analogs revealed that the major determinant for improved nucleotide selectivity is a significant reduction in kpol by >1000-fold over TTP misincorporation. These studies highlight the importance of structure–function relationships of modified nucleotides in dictating polymerase performance.

Using Atom Transfer Radical Polymerization for the Synthesis of Grafted PVDF Copolymers towards the Synthesis of Membranes

AbstractGraft copolymers of poly(vinylidene fluoride) (PVDF) with poly(3‐sulfopropyl methacrylic acid) (PVDF‐g‐PSPMA), poly(styrene‐4‐sulfonic acid) (PVDF‐g‐PSSA), and poly(dimethylaminoethyl methacrylate) (PDVFg‐PDMAEMA) were synthesized. The aforementioned grafted copolymers were prepared from the corresponding (PDVF‐g‐PSPMPS) poly(3‐sulfopropyl methacrylate potassium) and (PVDF‐g‐PSSS) poly(styrene‐4‐sulfonate sodium) salts using PVDF as a macroinitiator for atom transfer radical polymerization (ATRP). The copolymers were casted into membranes by the phase inversion method in aqueous media. The effects of polymerization time, degree of conversion, chain transfer agent (CTA) additive, crosslink process, and various solvents were investigated. The products were characterized by 1H and 13C NMR spectroscopy, IR spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). The maximum grafting incorporation was up to 26, 20 and 20 wt % for PSSA, PSPMA and PDMAEMA, respectively. The incorporation was reduced using a CTA additive. The most impressive feature of the graft copolymer membranes produced in this study are the improved water fluxes and polyethylene glycol (PEG) rejection properties when compared to the commercially available, pristine PVDF.

The Production of Lutein-Enriched Eggs with Dietary Chlorella

Two experiments were conducted to investigate the dietary effect of chlorella vulgaris on egg production and lutein incorporation into chicken eggs. In Exp. 1, a total of three hundred, 70 wk-old Hy-Line brown layers were divided into six groups with five replicates and fed each experimental diet (corn-SBM based control diet and diets with 0.1, 0.3 or 0.5% chlorella powder and with 0.8 or 2.4% chlorella cultured media) for 6 wk, respectively. The egg production in the groups fed diets containing the chlorella powder and chlorella cultured media were higher than that of the control group (p<0.001). As dietary chlorella levels increased, the yolk color linearly increased. However, there were no significant differences in egg-shell qualities. The layers fed diet with 2.4% chlorella cultured media showed the highest Haugh unit value. In Exp. 2, a total of one hundred-eight 80 wk-old Hy-Line brown layers were assigned into four groups with three replicates per group (9 birds per replicate). The birds were fed one of four experimental diets (0, 0.5, 1.0 or 2.0% chlorella powder) for 4 wk, followed by a 14 d feeding of a withdrawal diet devoid of chlorella powder. At 2 wk, the lutein greatly increased with increasing levels of chlorella powder in birds fed diets containing more than 1%. The maximum incorporation of lutein into eggs was reached after 2 or 3 wk of feeding diets with chlorella powder. After a 7 d withdrawal, the lutein contents of egg yolks in the groups fed diets with more than 1% chlorella powder were still higher than that of control group (p<0.05). No significant differences in the lutein levels were found among groups after a 14 d withdrawal period. These results indicated that the use of chlorella in layer diets was effective in improving egg production and egg quality and for the production of lutein fortified eggs.

Optimized Production of MLM Triacylglycerols Catalyzed by Immobilized Heterologous Rhizopus oryzae Lipase

AbstractResponse surface methodology was used to model and optimize the acidolysis of virgin olive oil with caprylic (C8:0) or capric (C10:0) acids, aimed at the production of low caloric triacylglycerols (TAG) of MLM type, in solvent free media, catalyzed by the heterologous Rhizopus oryzae lipase (r‐ROL) immobilized in Eupergit® C. This lipase was produced in the methylotrophic yeast Pichia pastoris Muts phenotype (experiments with C10:0) or a Mut+ phenotype (experiments with C8:0), under different operational conditions. The r‐ROL used in experiments with C10:0 presented a hydrolytic activity about 5 times of that presented by r‐ROL used in acidolysis with C8:0. The experiments were carried out following a central composite rotatable design, as a function of the molar ratio (MR) medium chain fatty acid/TAG (1.6–4.4) and temperature (25–55 °C). Convex surfaces described by second order polynomials as a function of MR and temperature were well fitted to fatty acid incorporation values. After 24‐h reaction, the predicted maximum incorporation of caprylic (15.5 mol%) or capric (33.3 mol%) acids in olive oil occurs at 37 and 35 °C, respectively, and at C8:0/TAG of 2.8:1 or C10:0/TAG of 3:1. These predicted optima were experimentally validated. Fermentation conditions used in r‐ROL production highly affected hydrolytic activity and to a lesser extent interesterification activity.

Use of immobilized phospholipase A1-catalyzed acidolysis for the production of structured phosphatidylcholine with an elevated conjugated linoleic acid content

Structured phosphatidylcholine (SPC) was successfully produced via immobilized phospholipase A 1 (PLA 1 ) – catalyzed acidolysis of phosphatidylcholine (PC) with conjugated linoleic acid (CLA). The effects of enzyme loading (2, 5, 10, 15 and 20%, with respect to the weight of substrates), temperature (20, 30, 40, 50 and 60 °C) and the molar ratio of substrates (1:2, 1:4, 1:6, 1:8 and 1:10, PC/CLA) were evaluated to maximize the incorporation of CLA into PC. The maximum incorporation of CLA achieved was ca. 90% for 24 h of reaction at 50 °C and 200 rpm, using a 1:4 substrate molar ratio and an enzyme loading of 15%.

Determining loading kinetics of drug releasing degradable shape-memory polymers

ABSTRACTModern concepts for biofunctional implants often comprise the controlled release of bioactive compounds to gain specific biofunctionalities. Here, amorphous and semi-crystalline copolyester-based shape-memory polymer (SMP) networks are reported as matrix for pharmaceutical applications. Drug loading of such crosslinked networks by swelling techniques requires tools to determine the actual payload. In this report, the capability of determining loading kinetics by mass increase or changes of drug concentration in the swelling medium is explored for two types of copolyester-based SMP networks differing in their crosslinking chemistry. Nitrofurantoin and ethacridine lactate served as hydrophobic and hydrophilic model drugs. It was found, that the absolute values of the determined payload did not systematically agree with those obtained by the more reliable technique of network cleavage and spectrophotometric quantification. However, the studies indicate that for both types of SMP materials and both drugs, maximum incorporation of the drugs occurred within a few hours. The time until equilibration depended on the network properties.