Source Of Macromolecules Research Articles

Eco-Corona Dictates Mobility of Nanoplastics in Saturated Porous Media: The Critical Role of Preferential Binding of Macromolecules

Nanoplastics are an increasing environmental concern. In aquatic environments, nanoplastics will acquire an eco-corona by interacting with macromolecules (e.g., humic substances and extracellular polymeric substances (EPS)). Here, we show that the properties of the eco-corona and, consequently, its ability to enhance the transport of nanoplastics vary significantly with the surface functionality of nanoplastics and sources of macromolecules. The eco-corona derived from the EPS of Gram-negative Escherichia coli MG1655 enhances the transport of polystyrene (PS) nanospheres in saturated porous media to a much greater extent than the eco-corona derived from soil humic acid and fulvic acid. In comparison, the eco-corona from all three sources significantly enhance the transport of carboxylated PS (HOOC-PS). We show that the eco-corona inhibits the deposition of the two types of nanoplastics to the porous media mainly via steric repulsion. Accordingly, an eco-corona consisting of a higher mass of larger-sized macromolecules is generally more effective in enhancing transport. Notably, HOOC-PS tends to acquire macromolecules of lower hydrophobicity than PS. The more disordered and flexible structures of such macromolecules may result in greater elastic repulsion between the nanoplastics and sand grains and, consequently, greater transport enhancement. The findings of this study highlight the critical role of eco-corona formation in regulating the mobility of nanoplastics, as well as the complexity of this process.

Evaluation of physicochemical, bioactive composition and profile of fatty acids in leaves of different olive cultivars

Olive leaves are agro-industrial residues resulting from pruning and / or olive harvesting, and are used in animal feed, as an organic fertilizer and as a source of compound extraction for various applications. This study aimed to carry out the physicochemical characterization, main bioactive compounds and the fatty acid profile of olive leaves from the cultivars Frantoio, Koroneike, Manzanilha, Arbosana and Arbequina. Proximal composition, pH, titratable acidity, minerals by MIP OES, bioactive compounds were determined by spectrophotometry, oleuropein and tocopherols by high performance liquid chromatography and the fatty acid profile by gas chromatography. The olive leaves had a high content of fibers and proteins, the predominant minerals were potassium and calcium, in addition the olive leaves had a high content of bioactive compounds, mainly flavonoids and carotenoids and the cultivar Koroneike had a higher content of oleuropein compared to the others. In relation to tocopherols, α-tocopherol stood out from the other tocopherols with the maximum concentration (63436.79 mg.100g-1) measured in the cultivar Arbequina. In view of the results found, it is concluded that olive leaves are sources of macromolecules, bioactive compounds and fatty acids, which can be extracted and applied in the most diverse areas.

Evaluation of Lignins of Trunk and Roots from Citrus sinensis L. Osbeck: A Large Available Brazilian Biomass

Citrus biomass is a source of biobased products and presents extensive chemical diversity. Among the structural macromolecules, lignins have been used in resins, bioplastics, and nanoencapsulation. Brazil has a large source of lignins, which are orange trees removed from groves that need to be renewed. However, the knowledge about these lignins is limited and little explored. Thus, this work aimed to evaluate the lignins from Citrus sinensis and to provide information on the interesting use of orange trees as a source of macromolecules. The lignins were isolated from the trunk, central and secondary roots from the orange tree by Technical Association of the Pulp and Paper Industry (TAPPI)-methods. The lignin contents for the extractive-free samples were 19.8 ± 0.19, 21.9 ± 0.36, and 19.5 ± 0.41% (m/m) in the trunk, central and secondary roots, respectively. Infrared (IR) and 13C nuclear magnetic resonance (NMR) analyses confirmed typical bands and chemical shifts to syringyl and guaiacyl units. These results are consistent with the features of lignins previously reported for orange tree branches and hardwood roots. The greatest amount of lignin in the orange tree was found in the central root. The lignins extractive-free by TAPPI-T264 cm-97 presented low solubility in organic solvents, due to their compaction and folding, which was confirmed by 13C NMR in the solid-state, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).

Isolation, fractionation and anticoagulant activity of a sulfated galactan extracted from the green algae Penicillus capitatus

ABSTRACT: Marine algae are natural sources of macromolecules known as sulfated polysaccharides. This class of compounds has attracted the interest of Pharmaceutical Sciences due to its pharmacological anticoagulant, antiplatelet and antithrombotic properties. Therefore, this study evaluated the anticoagulant potential of sulfated polysaccharides extracted from the algae Penicillus capitatus. The extracted sulfated polysaccharides were purified, partially characterized and their anticoagulant activity was evaluated. The extraction process followed by ethanol precipitation resulted in five fractions. Among the analyzed fractions, F44 contained highest concentration of sulfated polysaccharides. After the purified fraction F23, F44 displayed in vitro anticoagulant activity in a time testing for activated partial thromboplastin time and prothrombin time. The preferential mechanism effect was based on interactions between thrombin and factor Xa. Additional studies on structure pharmacological are required to test the viability of the use of sulfated polysaccharides as therapeutic agents.

Valorization of Mexican Ricinus communis L. Leaves as a Source of Minerals and Antioxidant Compounds

This research aimed to characterize the physicochemical and nutraceutical composition from two Mexican R. communis L. leaves accessions (R1 and R2) to valorize their use as a source of macromolecules, minerals, and bioactive compounds. The physicochemical (proximal composition, X-ray fluorescence and diffraction, FT-IR, and SEM) and nutraceutical composition (phenolic compounds and mono/oligosaccharides, GC–MS, untargeted metabolomics, and in silico interactions) were conducted for the analysis of the leaves. Both accessions exhibited a high amount of protein (41.70–39.58%) and ash (11.81–12.51%). The untargeted metabolomic profiled a major impact on antioxidative pathways. Compared to R1, R2 showed a higher (p < 0.05) content of ellagic and p-coumaric acids and catechin. Correlations with the in vitro antioxidant capacity and in silico analysis suggested ellagic acid, (+)-catechin, and ricin as candidates for the antioxidant potential. The mineral characterization highlighted calcium and potassium as the most abundant minerals, both confirmed by the SEM analysis. The FTIR spectra of the leaves partially identified the presence of ricin and ricinine, major protein and alkaloid, respectively, of the leaves. These results indicate that R. communis L. leaves are an attractive by-product that can serve as an alternative source for the obtention of protein, minerals, and antioxidant compounds.

Engineering of Aerogel-Based Biomaterials for Biomedical Applications.

Biomaterials with porous structure and high surface area attract growing interest in biomedical research and applications. Aerogel-based biomaterials, as highly porous materials that are made from different sources of macromolecules, inorganic materials, and composites, mimic the structures of the biological extracellular matrix (ECM), which is a three-dimensional network of natural macromolecules (e.g., collagen and glycoproteins), and provide structural support and exert biochemical effects to surrounding cells in tissues. In recent years, the higher requirements on biomaterials significantly promote the design and development of aerogel-based biomaterials with high biocompatibility and biological activity. These biomaterials with multilevel hierarchical structures display excellent biological functions by promoting cell adhesion, proliferation, and differentiation, which are critical for biomedical applications. This review highlights and discusses the recent progress in the preparation of aerogel-based biomaterials and their biomedical applications, including wound healing, bone regeneration, and drug delivery. Moreover, the current review provides different strategies for modulating the biological performance of aerogel-based biomaterials and further sheds light on the current status of these materials in biomedical research.

Preliminary Phytochemical Analysis and Chemical Characterization of Acetone Extract from Tender Coconut Mesocarp

Pharmacologists, Phytochemists and Life science Scientists are interested in identifying novel compounds from waste products. Tender coconut mesocarp is commonly used by coir industries for manufacturing bags, cups etc., Cost of that waste product is also less. Aim of the present study is to estimate the quantity of secondary metabolites and evaluate the presence of various pharmacologically active compounds in acetone extract of tender coconut mesocarp (TCM) by LC-MS analysis. The acetone extract of TCM is a rich source of macromolecules like carbohydrate, protein, and micromolecule like Vitamin C and secondary metabolites like phenolic compounds, flavonoids and tannin. LC-MS chromatogram of TCM acetone extract shows the presence of numerous active compounds including glucosylsphingosine, didesmethylimipramine sulfinpyrazone with 13.32, 21.67, 24.88 ppm respectively etc., In conclusion, TCM is a rich source of pharmacologically active phytoconstituents which can be used by pharmaceutical industry for the development of new drug for various ailments.

The effect of macromolecule and growth factor combinations on in vitrodevelopment of bovine embryos

This study was conducted to determine the effects of different macromolecule sources added to synthetic oviduct fluid (SOF) culture medium supplemented with growth factors on the development of bovine embryos and blastocyst morphology. Zygotes were distributed into 5 treatment groups. Cleavage, morula, and blastocyst rates were evaluated under a stereomicroscope. Trophectoderm (TE) and inner cell mass (ICM) cells were determined by differential staining method. It was found that bovine serum albumin (BSA), either alone or in combination with growth factors, as compared to the control or polyvinyl-alcohol (PVA) resulted in higher embryo yield and faster development during early bovine embryo culture. The quality of bovine embryos, based on the number of blastocyst cells and the ratio of ICM to total blastomeres, was affected by the sources of macromolecules and their combinations with growth factors. Growth factors supplemented to SOFaa media with BSA and PVA significantly increased the number of ICM cells and the ratio of ICM cells to total number of cells. In conclusion, replacing BSA with PVA depressed the blastocyst rate and cell numbers, and the number of blastomeres and ICM and TE cell numbers were affected by both the type of macromolecule and the growth factor supplements.

Fibroblasts within concentrated collagen hydrogels favour chronic skin wound healing

Apligraf(®), a skin substitute currently used in skin chronic wound treatment, acts as a source of macromolecules and cytokines to promote wound healing. Normal collagen hydrogel (NCH), obtained from collagen at low concentration (0.66 mg/ml), is the base of the dermal layer. Apligraf has several drawbacks, such as poor persistence of fibroblasts within the normal collagen hydrogel. In the present study we have evaluated concentrated collagen hydrogels at 5 mg/ml (CCH5s) as dermal substitutes for the treatment of skin chronic wounds. The effect of raised collagen concentration on hydrogel stability, cell growth, apoptosis and fibroblast phenotype was evaluated over 21 days in culture. In contrast to NCHs, CCH5s were more stable because no contraction was observed during the first week. CCH5 favoured cell proliferation and protected fibroblasts against apoptosis. At day 21, cell number assessed in CCH5 was around one million, i.e about 10 times higher than in NCH. Matrix metalloproteinases detection appeared lower in CCH5 than in NCH. In CCH5, fibroblasts exhibited a sustained collagen I gene expression for 14 days, while it was inhibited from day 4 in NCH. Moreover, gene expression of KGF was constant in CCH5 and that of VEGFA increased from day 7. Taken together, our results demonstrate that concentrated collagen hydrogels at 5 mg/ml can be considered as new candidates for cell therapy in chronic skin wounds. They are stable, enhance cell viability and allow gene expression of matrix macromolecules and cytokines involved in re-epithelialization or neovascularization.

Use of Fetuin Before and During Vitrification of Bovine Oocytes

After vitrification of oocytes, fertilization rates and subsequent development are unsatisfactory, possibly due in part to zona hardening. Foetal calf serum (FCS) can prevent zona hardening because of its fetuin content, but FCS composition varies among batches, and may contain viruses. In this study, we therefore compared media supplemented with different sources of macromolecules, 2% bovine serum albumin (BSA), 2% BSA + 1 mg/ml fetuin and 20% FCS, for handling oocytes for 10-30 min prior to vitrification. None of the treatments resulted in developmental rates comparable with the non-vitrified controls, but FCS inclusion in pre-vitrification handling medium resulted in higher blastocyst production per oocyte (p < 0.05) (10.8%) on day 9 of culture than BSA (5.3%) or BSA + fetuin (6.4%). Blastocysts developing from oocytes from all vitrification treatments were somewhat retarded relative to those developed from non-vitrified oocytes. We also tested the use of fetuin during vitrification as well as two different exposure times with cryoprotectants, 180 and 30 s. There was no significant effect of fetuin or exposure time on rates of subsequent blastocyst production.

Horseradish peroxidase: a reliable or a misleading tool for the investigations on the origin of the proteins of the aqueous humor?

The concept of the blood-aqueous barrier is largely based on the use of horseradish peroxidase (HRP). The present investigation was designed to check its reliability as a macromolecular tracer, especially with regard to the transport of plasma proteins. Rabbits were killed 5 min to 24 h after being intravenously injected with HRP. The tracer diffused rapidly, reaching the aqueous humor of the eye in 3 min or less and was detected at high concentration in the narrow space between the outer epithelial layer of the ciliary epithelium and the wall of the pervious capillaries in the stroma of the processes. HRP appeared to migrate from the blood to the posterior chamber, permeating the tight junctions, viz., the anatomical basis of the blood-aqueous barrier. It was detected at higher concentration at the anterior surface of the iris, at short time intervals; this was interpreted as penetration of the tracer from the aqueous humor of the anterior chamber. The choroid was also labeled in continuation with the reaction in the stroma of the pars plana of the ciliary body which, in turn, sometimes reached the iris root. Therefore, the pervious blood vessels of the choroid could be a source of macromolecules for the iris root. HRP also induced the formation of lysosomes in the ciliary epithelium. This can hardly be accepted as the way in which plasma proteins are physiologically transported to the aqueous humor. However, the pathway of HRP migration over short time intervals seems to be in agreement with previous research indicating that the entrance of serum albumin into the posterior chamber is the first step of its incorporation into the aqueous humor.

Effect of Different Protein Supplements on Motility and Plasma Membrane Integrity of Frozen-Thawed Stallion Spermatozoa

Three experiments were conducted to evaluate the effect of different macromolecule components (egg yolk, skim milk, and BSA) in a widely employed extender for cryopreservation of horse semen. Spermatozoal motility (MOT) and the percentage of spermatozoa with an intact plasma membrane (IPM) were evaluated in frozen-thawed samples. In the first experiment (four Draft Horse stallions, four ejaculates each) a standard freezing extender containing 20% whole egg yolk was modified by replacing extender components (glucose-EDTA solution, 11% lactose solution) with an increasing volume of a skim milk diluent (0, 25, 50, and 75%, v/v). The best results were obtained with an extender containing 75% (v/v) skim milk solution (MOT 24.7%; IPM 46.6%). This extender was further tested in Experiment 2 (three Draft Horse stallions, four ejaculates each) by varying the amount of egg yolk (10 or 20%) and by addition of 5% BSA. Neither the amount of egg yolk nor the addition of BSA significantly influenced postthaw results. Selected extenders from the previous experiments were tested in Experiment 3 (three stallions, four ejaculates each). Again, a mixture of 20% whole egg yolk and a skim milk solution provided the best results (MOT 41.7%; IPM 54.2%). The results of this study indicate that the inclusion of different sources of macromolecules (e,g., egg yolk and skim milk) can improve motility and plasma membrane integrity of frozen-thawed horse spermatozoa.

Receptors on Airway Gland Cells

Airway submucosal glands are by volume the most important source of macromolecules in airway secretions. These secretions, containing gel-forming mucins, antibacterial proteins, and antiproteases, comprise the major defensive barrier protecting the host against airborne pathogens. The identification of the mechanisms regulating secretion from the submucosal glands is key to understanding the genesis of this barrier and how it is altered by disease processes. Using a variety of methods, we and others have identified on the gland cells of several species receptors specific for ACh, norepinephrine, substance P, VIP, PGE1, PGE2, PGA1, PGD2, histamine and bradykinin. These receptors all participate in modulating the secretory activity of the airway submucosal glands. Studies of homogeneous cultures of bovine airway serous cells have yielded detailed information regarding the beta-adrenergic receptor on these cells. Using radioligand binding techniques, we found evidence for the presence of a single high affinity beta receptor of beta-2 subtype. Occupancy of this receptor by isoproterenol causes an elevation in the concentration of intracellular cAMP, which in turn stimulates the phosphorylation of a subset of cytoplasmic and membrane proteins. Based on the kinetics and pharmacology of these effects, it is likely that cAMP functions as a second messenger in the serous cell secretory pathway, probably acting through protein kinases. Current efforts are directed at identification of those phosphoproteins whose phosphorylation and dephosphorylation times are consistent with their possible roles in secretion.