Interleukin-1β and -6 release from immune cells by DOPA-based melanin as free pigment or complexed to carboxymethylcellulose

Ft Ir ◽

This report expands our ongoing research efforts into the non-enzymatic synthesis of melanins. We have explored four different methods for the synthesis of L-DOPA based melanins and evaluated the reproducibility of some of their physic-chemical properties. The melanins were synthesized through the addition of NaOH, tyrosinate or Fe2+/H2O2. Two different approaches for the reactions involving Fe2+ and H2O2 were tested: a) addition of H2O2 spread out over multiple days or b) addition of H2O2 in one fraction at the start of the reaction. The physic-chemical properties of the melanins explored involved: 1) retention on size exclusion chromatography column, 2) FT-IR spectroscopy, 3) UV-Vis spectroscopy and 4) the capacity to reduce a redox dye, dichlorophenolindophenol. Overall the results obtained indicated that 1) the various synthesis methods lead to melanins with reproducible physic-chemical properties, 2) that the melanins synthesized in the presence of Fe2+/H2O2 are distinctly different from the melanins synthesized in the presence of NaOH or tyrosinate and 3) that no distinctly different melanins were generated when comparing the two different synthesis approaches involving Fe2+/H2O2. Only the melanins synthesized in the presence of Fe2+/H2O2 appeared to possess the capacity to reduce dichlorophenolindophenol.

Hydroxyapatite-poly(d,l-lactide) Nanografts. Synthesis and Characterization as Bone Cement Additives

Molecules ◽

10.3390/molecules26020424 ◽

2021 ◽

Vol 26 (2) ◽

pp. 424

Author(s):

Kristina L. Goranova ◽

Anne Kathrine Kattenhøj Sloth Overgaard ◽

Ivan Gitsov

Keyword(s):

Bone Cement ◽

Molecular Mass ◽

Size Exclusion ◽

Thermal Methods ◽

Mass Distributions ◽

Ft Ir ◽

Thermal Analysis Techniques ◽

Hydroxyapatite Nanocrystals ◽

This paper reports the creation of hydroxyapatite/polyester nanografts by “graft-from” polymerization of d,l-lactide with [Ca5(OH)(PO4)3]2 as the initiator and tin(II)-2-ethylhexanoate as the catalyst. Model polymerizations were performed with cyclooctanol as initiator to confirm the grafting on the surface of the hydroxyapatite nanocrystals. Polymers with the highest molecular mass (Mn) between 4250 Da (cyclooctanol) and 6100 Da (hydroxyapatite) were produced. In both cases the molecular mass distributions of the polymers formed were monomodal. The materials obtained were characterized by size-exclusion chromatography, NMR and FT-IR spectroscopy, and thermal methods. Their suitability as additives for commercial bone cement (Simplex P Speedset, Stryker Orthopaedics) has been confirmed by thermal analysis techniques and mechanical testing. The results obtained show that addition of the hydroxyapatite/ polyester nanografts improved both thermal and mechanical properties of the bone cement.

Synthesis of L-DOPA Based Melanins with Reproducible Physic-Chemical Properties

10.26434/chemrxiv.7471388 ◽

2018 ◽

Author(s):

Koen Vercruysse ◽

Jayla Moore

Keyword(s):

Ir Spectroscopy ◽

Enzymatic Synthesis ◽

Chemical Properties ◽

Size Exclusion ◽

Synthesis Methods ◽

Ongoing Research ◽

Vis Spectroscopy ◽

Ft Ir ◽

This report expands our ongoing research efforts into the non-enzymatic synthesis of melanins. We have explored four different methods for the synthesis of L-DOPA based melanins and evaluated the reproducibility of some of their physic-chemical properties. The melanins were synthesized through the addition of NaOH, tyrosinate or Fe2+/H2O2. Two different approaches for the reactions involving Fe2+ and H2O2 were tested: a) addition of H2O2 spread out over multiple days or b) addition of H2O2 in one fraction at the start of the reaction. The physic-chemical properties of the melanins explored involved: 1) retention on size exclusion chromatography column, 2) FT-IR spectroscopy, 3) UV-Vis spectroscopy and 4) the capacity to reduce a redox dye, dichlorophenolindophenol. Overall the results obtained indicated that 1) the various synthesis methods lead to melanins with reproducible physic-chemical properties, 2) that the melanins synthesized in the presence of Fe2+/H2O2 are distinctly different from the melanins synthesized in the presence of NaOH or tyrosinate and 3) that no distinctly different melanins were generated when comparing the two different synthesis approaches involving Fe2+/H2O2. Only the melanins synthesized in the presence of Fe2+/H2O2 appeared to possess the capacity to reduce dichlorophenolindophenol.

Structure of a shear-thickening polysaccharide extracted from the New Zealand black tree fern, Cyathea medullaris

10.26686/wgtn.12597809.v1 ◽

2020 ◽

Author(s):

M Wee ◽

M Mastrangelo ◽

Susan Carnachan ◽

Ian Sims ◽

K Goh

Keyword(s):

New Zealand ◽

Uronic Acid ◽

Average Molecular Weight ◽

Shear Thickening ◽

Water Soluble ◽

Size Exclusion ◽

Resonance Spectroscopy ◽

Tree Fern ◽

13C Nuclear Magnetic Resonance ◽

Exclusion Chromatography

A shear-thickening water-soluble polysaccharide was purified from mucilage extracted from the fronds of the New Zealand black tree fern (Cyathea medullaris or 'mamaku' in Māori) and its structure characterised. Constituent sugar analysis by three complementary methods, combined with linkage analysis (of carboxyl reduced samples) and 1H and 13C nuclear magnetic resonance spectroscopy (NMR) revealed a glucuronomannan comprising a backbone of 4-linked methylesterified glucopyranosyl uronic acid and 2-linked mannopyranosyl residues, branched at O-3 of 45% and at both O-3 and O-4 of 53% of the mannopyranosyl residues with side chains likely comprising terminal xylopyranosyl, terminal galactopyranosyl, non-methylesterified terminal glucopyranosyl uronic acid and 3-linked glucopyranosyl uronic acid residues. The weight-average molecular weight of the purified polysaccharide was ~1.9×106Da as determined by size-exclusion chromatography coupled with multi-angle laser light scattering (SEC-MALLS). The distinctive rheological properties of this polysaccharide are discussed in relation to its structure. © 2014 Elsevier B.V.

Fibrillar pharmacology of functionalized nanocellulose

Scientific Reports ◽

10.1038/s41598-020-79592-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sam Wong ◽

Simone Alidori ◽

Barbara P. Mello ◽

Bryan Aristega Almeida ◽

David Ulmert ◽

...

Keyword(s):

Aspect Ratio ◽

Fluorescent Dyes ◽

Pharmacokinetic Profile ◽

Water Soluble ◽

Size Exclusion ◽

Hydroxyl Groups ◽

Target Tissue ◽

Specific Accumulation

AbstractCellulose nanocrystals (CNC) are linear organic nanomaterials derived from an abundant naturally occurring biopolymer resource. Strategic modification of the primary and secondary hydroxyl groups on the CNC introduces amine and iodine group substitution, respectively. The amine groups (0.285 mmol of amine per gram of functionalized CNC (fCNC)) are further reacted with radiometal loaded-chelates or fluorescent dyes as tracers to evaluate the pharmacokinetic profile of the fCNC in vivo. In this way, these nanoscale macromolecules can be covalently functionalized and yield water-soluble and biocompatible fibrillar nanoplatforms for gene, drug and radionuclide delivery in vivo. Transmission electron microscopy of fCNC reveals a length of 162.4 ± 16.3 nm, diameter of 11.2 ± 1.52 nm and aspect ratio of 16.4 ± 1.94 per particle (mean ± SEM) and is confirmed using atomic force microscopy. Size exclusion chromatography of macromolecular fCNC describes a fibrillar molecular behavior as evidenced by retention times typical of late eluting small molecules and functionalized carbon nanotubes. In vivo, greater than 50% of intravenously injected radiolabeled fCNC is excreted in the urine within 1 h post administration and is consistent with the pharmacological profile observed for other rigid, high aspect ratio macromolecules. Tissue distribution of fCNC shows accumulation in kidneys, liver, and spleen (14.6 ± 6.0; 6.1 ± 2.6; and 7.7 ± 1.4% of the injected activity per gram of tissue, respectively) at 72 h post-administration. Confocal fluorescence microscopy reveals cell-specific accumulation in these target tissue sinks. In summary, our findings suggest that functionalized nanocellulose can be used as a potential drug delivery platform for the kidneys.

Behavior of xylans from the Eucalyptus species. Part 2. Characterization of 4-O-methylglucuronoxylans isolated from black liquors of kraft pulping of Eucalyptus grandis and E. urophylla

Holzforschung ◽

10.1515/hf-2012-0035 ◽

2013 ◽

Vol 67 (2) ◽

pp. 123-128

Author(s):

Andréia S. Magaton ◽

Teresa Cristina F. Silva ◽

Jorge Luiz Colodette ◽

Dorila Piló-Veloso ◽

Flaviana Reis Milagres ◽

...

Keyword(s):

Average Molecular Weight ◽

Eucalyptus Grandis ◽

Kraft Pulping ◽

Raw Material ◽

Size Exclusion ◽

Eucalyptus Species ◽

Ft Ir ◽

Black Liquors

Abstract 4-O-methylglucuronoxylans isolated from Eucalyptus grandis and Eucalyptus urophylla kraft black liquors (KBLs) were chemically characterized by Fourier transform infrared spectroscopy (FT-IR), size exclusion chromatography (SEC), and nuclear magnetic resonance (NMR) spectroscopy. Doses of alkali charge, expressed as active alkali (AA), were 16, 17, and 18% while the sulfidity was kept at 25%. Kappa numbers of 19.1, 17.5, and 16.1 for E. grandis and 20.4, 16.8, and 15.4 for E. urophylla were obtained. At higher alkali charges, the recovery of xylans from the KBLs was lower and the degree of substitution of xylans with uronic acids decreased. The average molecular weight (Mw) of the recovered xylans was greater under conditions of mild pulping, i.e., in the case of pulps with higher kappa numbers. Mw of xylans ranged from 16.1 to 19.1 kDa for E. grandis and from 15.4 to 20.4 kDa for E. urophylla. The xylans from KBL may be useful as pulp modifying agents or as a raw material for advanced applications.

Nano-Sized [60]Fullerene-Cyclodextrin Molecules

MRS Proceedings ◽

10.1557/proc-675-w7.3.1 ◽

2001 ◽

Vol 675 ◽

Author(s):

Jeong-Seo Park ◽

Han-Chang Kang ◽

Kurt E. Geckeler

Keyword(s):

Biomedical Applications ◽

Addition Reaction ◽

Water Soluble ◽

Separation And Purification ◽

Subsequent Reaction ◽

Fullerene Derivatives ◽

Covalently Bonded ◽

Scattering Measurements ◽

Ft Ir ◽

ABSTRACTAs [60]fullerene is a very hydrophobic macromolecule, there have been a number of attempts to make it more hydrophilic for biomedical applications. By attaching hydrophilic moieties such as poly(oxyethylene)(POE) chains and cyclodextrin molecules to [60]fullerene, novel water-soluble and biocompatible materials have been successfully prepared [1,2].The synthesis of novel macrocyclic fullerene conjugates which are water-soluble is reported. The telechelic fullerene derivatives have been prepared via addition reaction of POE-based arms with covalently bonded β-cyclodextrin (CD) to [60]fullerene. To this end, a mono-tosylated CD derivative has been prepared in pyridine and then reacted with an amino-functional POE in the presence of triethylamine. The subsequent reaction of [60]fullerene with the hydrophilic POE-conjugated CD-derivative yielded the macrofullerene after separation and purification procedures.The macrocyclic [60]fullerene derivatives obtained were soluble in water and characterized by UV-VIS and FT-IR spectroscopy as well as light scattering measurements and thermogravimetric analysis.

Characteristics of Konjac Glucomannan (KGM) in A.bulbifer Compared with that in A.rivieri and A.albus

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.236-238.2045 ◽

2011 ◽

Vol 236-238 ◽

pp. 2045-2052 ◽

Cited By ~ 3

Author(s):

Qiao Wang ◽

Jian Wang ◽

Geng Zhong

Keyword(s):

Chemical Structure ◽

Average Molecular Weight ◽

Konjac Glucomannan ◽

Water Soluble ◽

Soluble Dietary Fiber ◽

Physiochemical Properties ◽

Ft Ir ◽

Main Component ◽

Ft Ir Spectroscopy ◽

Southwest Part

Amorphophallus bulbifer (A. bulbifer) is a promising species in Amorphophallus sp., with great potentiality of developing, low risk for cultivation and considerable commercial benefits, mainly locates in tropical and subtropical regions or near the equator. Konjac glucomannan (KGM) is the main component of Amorphophallus tuber which is a water-soluble dietary fiber. In this work, some physiochemical properties of KGM in three Amorphophallus species flour [one was A.bulbifer, the other two were current main species namely Amorphophallus rivieri (A. rivieri) and Amorphophallus albus (A. albus)] were studied and compared with each other. The KGM content in A. rivieri, A. albus and A. bulbifer flour were 85.03%, 76.28% and 88.07% (w/w), respectively. The apparent viscosity, viscosity average molecular weight, whiteness, gel-forming properties and chemical structure of KGM in the three flours were investigated by using viscometer, colorimeter, texture analyzer and Fourier transform infrared (FT-IR) spectroscopy. The results indicated that the viscosity and Mw of A. bulbifer was the largest, gel strength was almost same (p>0.05) and the molecular structure were of no differences of three KGM. It may be proposed that transplanting A. bulbifer from its native land in the tropical and subtropical regions to temperate zone in the southwest part of China would be feasible, and it would cause the revolution of Amorphophallus sp. and more considerable benefits.

Preliminary Characterization of a Homogeneous Polysaccharide with Anticomplement Activity from Sijunzi Decoction

Journal of Chemistry ◽

10.1155/2018/8642653 ◽

2018 ◽

Vol 2018 ◽

pp. 1-8 ◽

Cited By ~ 3

Author(s):

Ruijun Wang ◽

Yunfei Ji ◽

Ying Peng ◽

Xiaobo Li

Keyword(s):

Immune System ◽

Size Exclusion ◽

Molar Ratio ◽

Classical Pathway ◽

Glycosidic Bonds ◽

Atomic Force ◽

Ft Ir ◽

Immune System Regulation

Sijunzi decoction (SJZD) is a classical herbal prescription in traditional Chinese medicine (TCM) used for enhancing the function of immune system. In previous studies, a polysaccharide fraction S-3 was screened from SJZD by assessment of immune system regulation, intestinal microbiota, and SCFA in order to explore the immune active ingredients in SJZD. In the present study, S-3 was further purified, and a homogeneous polysaccharide S-3-1 with a molecular mass of 13.5 × 104 Da was obtained after further fractionation by Sephadex G-150 size-exclusion chromatography. The immunological activities of S-3-1 were assayed in vitro for the first time. The determination of the anticomplement activity showed that S-3-1 displayed inhibitory effects on classical pathway of the complement system, with CH50 values of 530 μg/mL. The FT-IR analysis showed that S-3-1 had absorptive peaks characteristic of polysaccharides. The methylation and GC-MS analysis showed that it is comprised of Rha, Ara, Xyl, Man, Gal, and Glc in a relative molar ratio of 0.35 : 0.37 : 1.4 : 0.31 : 3 : 0.8 and that it mainly contained 1,4-linked-Glc and 1,6-linked-Gal glycosidic bonds. The morphology of S-3-1 was observed by atomic force microscope (AFM). These results provided evidences for tracking the material basis of SJZD immune activity.

Analysis of the substituent distribution along the chain of water-soluble methyl cellulose by combination of enzymatic and chemical methods

Holzforschung ◽

10.1515/hf.2004.013 ◽

2004 ◽

Vol 58 (1) ◽

pp. 97-104 ◽

Cited By ~ 10

Author(s):

B. Saake ◽

S. Lebioda ◽

J. Puls

Keyword(s):

Anion Exchange ◽

Size Exclusion Chromatography ◽

Methyl Cellulose ◽

Anion Exchange Chromatography ◽

Exchange Chromatography ◽

Degree Of Substitution ◽

Water Soluble ◽

Size Exclusion ◽

C Nmr

Abstract Four methyl cellulose samples in the degree of substitution range from 0.5 to 2.0 were characterised by combination of different analytical methods. Samples were analysed regarding their partial degree of substitution by hydrolysis and anion exchange chromatography with pulsed amperometric detection. For calibration of the chromatographic system, standard substances were isolated by preparative HPLC and their structure was confirmed by 13C-NMR spectroscopy. For two methyl cellulose samples per-acetylation and 13C-NMR with inverse gated decoupling was carried out for comparison with the chromatographic analysis. Endoglucanase fragmentation of methyl celluloses was performed and water-soluble and insoluble fractions were analysed separately. A preparative size exclusion chromatography system for enzymatic-degraded water-soluble methyl cellulose was developed and the molar masses of the individual fractions were examined by analytical size exclusion chromatography. By combination of endoglucanase fragmentation, preparative chromatography, hydrolysis and anion exchange chromatography an approach for the analysis of the substitutent distribution along the polymeric chain of water-soluble methyl cellulose could be established.