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Eugenol is a phenolic compound largely found in the clove essential oil that possesses promising biological activity. However, its low water solubility is a major concern and ...encapsulation is an alternative to improve water affinity. The objective of this work was to produce nanostructured lipid carriers (NLC) by hot homogenization/ultrasound emulsification and to evaluate the effect of free and encapsulated clove oil on the in vitro cholinesterase enzymes modulation using Drosophila melanogaster (DM) tissue. The NLC composed of a natural wax (carnauba or beeswax) and crodamol showed an average diameter between 121 and 367 nm with good dispersion and colloidal stability. The spherical shape and solid character together with the semi-crystalline environment confirm the formation of NLC. DSC analysis indicated polymorphic transition events of the waxes. In vitro tests using DM demonstrated that free clove oil showed a good inhibition of the butyryl and acetylcholinesterase enzymes above a concentration of 10 mM, with IC50 values of 4.3 and 3.5 mM, respectively. The dispersions of the NLC loaded with clove oil showed a decrease in the IC50 enzymes values, indicating the preservation of the clove essential oil and suggesting an increased in the solubility. Results indicate that NLC dispersions have good potential to be used for foods and cosmetic aqueous formulations possessing biological activity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
BSA adsorption onto negatively and positively charged polystyrene nanoparticles was investigated. The nanoparticles were characterized in terms of particle size, zeta potential, surface group ...density, and morphology. The adsorption behavior of BSA on the particle surface, as a function of pH and overall charge of the particle, was studied using ITC. Different thermodynamic data such as enthalpy changes upon binding and stoichiometry of the systems were determined and discussed. The degree of surface coverage with BSA was calculated using the thermodynamic data. The cellular uptake of particles before and after BSA adsorption was studied using HeLa cells in the presence and absence of supplemented FCS in the cell culture medium.
The interaction between differently functionalized polystyrene nanoparticles and BSA is studied. The maximum affinity is found for phosphonic‐acid‐functionalized nanoparticles, possibly because of the higher density of functional groups in this case and the inceased charge of the phosphonate groups. “Precoating” of the particle surfaces with BSA reduces the particle uptake into cells slightly.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Biodegradability is a key feature for the application of polymeric devices in medicine. This study reports an experimental and theoretical study of the degradation of poly(thioether-ester) (PTEe) ...nanoparticles in aqueous media. The α,ω-diene diester derived from vegetable oil, 1,3-propylene diundeca-10-polenoate (Pd10e), was used as monomer in the solvent-free synthesis of Pd10e-based nanoparticles (A-PTEe nanoparticles) via thiol-ene miniemulsion polymerization. The theoretical partition coefficients of A-PTEe and a PTEe based on dianhydro-
d
-glucityl diundec-10-enoate (DGU) (B-PTEe nanoparticles) were calculated using density functional theory (DFT), in order to compare their degradation behavior. The results showed that A-PTEe is more hydrophilic than B-PTEe, thus indicating the possible faster degradation of the former. The experimental degradation studies showed that, in fact, A-PTEe nanoparticles are faster degraded than B-PTEe, presenting substantial molecular weight decrease, which confirms the theoretical results. The effects of degradation could be observed in the chemical composition and thermal properties of the polymer. Considering its applicability potential as a biomaterial due to its fast degradation behavior, the cytotoxicity of A-PTEe nanoparticles and its degradation products were evaluated. In vitro assays confirmed the biocompatibility of A-PTEe nanoparticles and its degradation products when exposed on fibroblasts and red blood cells. These results suggest A-PTEe nanoparticles can be promising candidates as biobased nanocarriers for biomedical applications.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Superparamagnetic iron oxide nanoparticles (SPIONs) have their use approved for the diagnosis/treatment of malignant tumors and can be metabolized by the organism. To prevent embolism caused by these ...nanoparticles, they need to be coated with biocompatible and non-cytotoxic materials. Here, we synthesized an unsaturated and biocompatible copolyester, poly (globalide-
-ε-caprolactone) (PGlCL), and modified it with the amino acid cysteine (Cys) via a thiol-ene reaction (PGlCLCys). The Cys-modified copolymer presented reduced crystallinity and increased hydrophilicity in comparison to PGlCL, thus being used for the coating of SPIONS (SPION@PGlCLCys). Additionally, cysteine pendant groups at the particle's surface allowed the direct conjugation of (bio)molecules that establish specific interactions with tumor cells (MDA-MB 231). The conjugation of either folic acid (FA) or the anti-cancer drug methotrexate (MTX) was carried out directly on the amine groups of cysteine molecules present in the SPION@PGlCLCys surface (SPION@PGlCLCys_FA and SPION@PGlCLCys_MTX) by carbodiimide-mediated coupling, leading to the formation of amide bonds, with conjugation efficiencies of 62% for FA and 60% for MTX. Then, the release of MTX from the nanoparticle surface was evaluated using a protease at 37 °C in phosphate buffer pH~5.3. It was found that 45% of MTX conjugated to the SPIONs were released after 72 h. Cell viability was measured by MTT assay, and after 72 h, 25% reduction in cell viability of tumor cells was observed. Thus, after a successful conjugation and subsequent triggered release of MTX, we understand that SPION@PGlCLCys has a strong potential to be treated as a model nanoplatform for the development of treatments and diagnosis techniques (or theranostic applications) that can be less aggressive to patients.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The use of green sources for materials synthesis has gained popularity in recent years. This work investigated the immobilization of lipase NS-40116 (
Thermomyces lanuginosus
lipase) in polyurethane ...foam (PUF) using a biopolyol obtained through the enzymatic glycerolysis between castor oil and glycerol, catalyzed by the commercial lipase Novozym 435 for the PUF formation. The reaction was performed to obtain biopolyol resulting in the conversion of 64% in mono- and diacylglycerol, promoting the efficient use of the reaction product as biopolyol to obtain polyurethane foam. The enzymatic derivative with immobilized lipase NS-40116 presented apparent density of 0.19 ± 0.03 g/cm
3
and an immobilization yield was 94 ± 4%. Free and immobilized lipase NS-40116 were characterized in different solvents (methanol, ethanol, and propanol), temperatures (20, 40, 60 and 80 °C), pH (3, 5, 7, 9 and 11) and presence of ions Na
+
, Mg
++
, and Ca
++
. The support provided higher stability to the enzyme, mainly when subjected to acid pH (free lipase lost 80% of relative activity after 360 h of contact, when the enzymatic derivative lost around 22%) and high-temperature free lipase lost 50% of relative activity, while the immobilized remained 95%. The enzymatic derivative was also used for esterification reactions and conversions around 66% in fatty acid methyl esters, using abdominal chicken fat as feedstock, were obtained in the first use, maintaining this high conversion until the fourth reuse, proving that the support obtained using environmentally friendly techniques is applicable.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Benzyl propionate is an aromatic ester that possesses a fruity odor and is usually found in nature in the composition of some fruits such as plums and melons. This work aimed for the benzyl ...propionate synthesis by esterification using a new immobilized enzyme preparation with low-cost material from
Candida antarctica
(NS 88011) and three commercial immobilized lipases (Novozym 435, Lipozyme TL-IM and Lipozyme RM-IM). Novozym 435 had the best performance even when the solvent
tert
-butanol was absent of the reaction medium. Results from a 2
2
factorial design showed that an increase in the enzyme amount led to a higher conversion, even when the temperature was kept at the low value. Currently, no research had synthesized successfully benzyl propionate via esterification mediated by lipases; and we reached an ester conversion of ~ 44% after 24 h indicating that it is a promising route for benzyl propionate biotechnological production.
Graphical abstract
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The silver nanoparticles (AgNPs) green synthesis has been investigated by selecting naturally occurred reduction and stabilizing/capping agents. In this work, Ilex paraguariensis aqueous extract in ...the one-step biosynthesis of AgNPs is reported. The synthesis was carried out at room temperature under different pH (5.0, 6.8 and 8.5) and extract concentrations (2.5, 5.0 and 7.5% v v
−1
) resulting in average diameters ranging from 34 to 144 nm and polydispersity index (PDI) up to 0.51. The morphological characterization was performed by Transmission Electron Microscopy, associated with the UV-Vis Spectroscopy, showing that at higher pH the shape of AgNPs was more spherical rather than ellipsoidal. X-ray diffraction (XRD) pattern of AgNPs exhibited 2θ values corresponding to silver nanocrystals. Colloidal AgNPs solution synthesized with pH 8.5 and extract concentration of 2.5% v v
−1
remained stable for 10 months of storage at ambient temperature. Fourier Transform Infrared Spectroscopy suggested that the polyphenols were responsible for the AgNPs formation. AgNPs presented bacteriostatic and bactericidal activity. AgNPs presented in vitro rat brain acetylcholinesterase (AChE) activity, with higher inhibition potential at 200 µL. So, it is concluded that AgNPs were synthesized with success, the pH and extract concentration influences in AgNPs size and morphology, consequently in its antimicrobial and AChE activity.
•CalB lipase was immobilized in PEGylated poly(urea-urethane) nanoparticles by step miniemulsion polymerization.•Crodamol showed a protective effect on the enzyme.•PEGylated poly(urea-urethane) ...nanoparticles as a new alternative to immobilization support.•A promising immobilization method was developed.
In this work, Candida antarctica lipase B (CalB) was immobilized in PEGylated poly(urea-urethane) nanoparticles by step miniemulsion polymerization. The nanoparticles were synthesized using isophorone diisocyanate (IPDI) and polycaprolactone diol (PCL530) as monomers and crodamol as hydrophobe. The aqueous phase was composed by DI water, surfactant (SDS), PEG400 and free enzyme. The miniemulsion was prepared by sonication at different power intensity (70 and 90%) for 1, 2, and 3min. The enzymatic activity was determined by esterification of lauric acid and n-propyl alcohol. The thermal stability was evaluated at different temperatures and times. The highest enzyme activity (21U/mg) was obtained at 70% ultrasound power intensity for 2min, resulting in nano-size particle with an average diameter of 158nm. After 3h of incubation, the relative activities of the immobilized and free enzymes were 71.5 and 64.5%, respectively, at 40°C. FTIR spectrum and optical fluorescence microscopy images confirmed the immobilization of enzyme in PEGylated poly(urea-urethane) nanoparticles.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Enzymatically crossliked gelatin hydrogel was submitted to two different drying methods: air drying and freeze drying. The resulting polymeric tridimensional arrangement (compact or porous, ...respectively) led to different thermal and swelling properties. Significant differences (p < 0.05) on thermal and mechanical characteristics as well as swelling in non-enzymatic gastric and intestinal simulated fluids (37 ºC) were detected. Water absorption data in such media was modelled according to Higuchi, Korsmeyer-Peppas, and Peppas-Sahlin equations. Freeze dried hydrogel showed Fickian diffusion behavior while air dried hydrogels presented poor adjustment to Higuchi model suggesting the importance of the relaxation mechanism at the beginning of swelling process. It was possible to conclude that the same gelatin hydrogel may be suitable to different applications depending on the drying process used.
Crosslinking of an unsaturated aliphatic polyester poly(globalide) (PGl) by bistriazolinediones (bisTADs) is reported. First, a monofunctional model compound, phenyl-TAD (PTAD), was tested for PGl ...functionalisation.
H-NMR showed that PTAD-ene reaction was highly efficient with conversions up to 97%. Subsequently, hexamethylene bisTAD (HM-bisTAD) and methylene diphenyl bisTAD (MDP-bisTAD) were used to crosslink electrospun PGl fibres via one- and two-step approaches. In the one-step approach, PGl fibres were collected in a bisTAD solution for
crosslinking, which resulted in incomplete crosslinking. In the two-step approach, a light crosslinking of fibres was first achieved in a PGl non-solvent. Subsequent incubation in a fibre swelling bisTAD solution resulted in fully amorphous crosslinked fibres. SEM analysis revealed that the fibres' morphology was uncompromised by the crosslinking. A significant increase of tensile strength from 0.3 ± 0.08 MPa to 2.7 ± 0.8 MPa and 3.9 ± 0.5 MPa was observed when PGI fibres were crosslinked by HM-bisTAD and MDP-bisTAD, respectively. The reported methodology allows the design of electrospun fibres from biocompatible polyesters and the modulation of their mechanical and thermal properties. It also opens future opportunities for drug delivery applications by selected drug loading.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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