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1.
Pak J Biol Sci ; 25(9): 822-826, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36098084

RESUMEN

<b>Background and Objective:</b> <i> Chalcorana chalconota </i>is a complex frog species in West Sumatra which has been revised and designated as <i>Chalcorana parvaccola</i> and <i>Chalcorana rufipes</i> based on several studies such as morphology and genetics. Other studies such as protein band patterns can be a marker to differentiate species. This research was done to determine and prove the variations of protein band patterns found in skin secretions of the <i>C. chalconota </i>species complex. <b>Materials and Methods:</b> Frog samples were collected in the Pasia Laweh area, Pesisir Selatan, West Sumatra. The standard length measurement of the frog was carried out to determine the voltage that will be applied to the frog using an electric shock device (TAS/transcutaneous amphibian stimulator) in the process of removing the frog's skin secretions. Frog skin secretions were taken and used to see the pattern of protein bands using the SDS-PAGE method. <b>Results:</b> The protein band patterns of skin secretions of <i>C. chalconota</i> species complex were different between <i>C. parvaccola</i> and <i>C. rufipes</i>. In the skin secretions of <i>C. parvaccola</i>, there were eight protein bands with a molecular weight ranging between 12-103 kDa while for <i>C. rufipes</i> there were seven protein bands with a molecular weight ranging between 12-102 kDa. There were six protein bands shared by these two species. Two bands were only found in the skin secretions of <i>C. parvaccola</i> and one band was only found in <i>C. rufipes</i>. <b>Conclusion:</b> Pattern and molecular weight of protein in <i>C. parvaccola</i> and <i>C. rufipes</i> skin secretions can be used as protein markers to distinguish the two species.


Asunto(s)
Piel , Indonesia , Peso Molecular , Piel/metabolismo
2.
Carbohydr Polym ; 296: 119971, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-36088010

RESUMEN

Exopolysaccharide (EPS) isolated from Lactobacillus helveticus SNA12 were purified, and one fraction (SNA12-EPS) was obtained. The structure of SNA12-EPS was proposed using Fourier-transform infrared spectroscopy, gas chromatography-mass spectrometry, and nuclear magnetic resonance. Results showed that SNA12-EPS was rich in galactose and glucose with the molar ratios of 2.1:1.0, and SNA12-EPS possessed the repeat units of →3)-ß-D-Glcp-(1→3)-ß-D-Glcp-(1→4)-ß-D-Galp-(1→ with an average molecular weight of 3.81 × 105 Da. The scanning electron microscope results showed that SNA12-EPS had a tight structure with a smooth and uneven surface. Furthermore, the prebiotic potential of SNA12-EPS was performed using in vitro simulated digestion with human faecal fermentation. SNA12-EPS was not digested by digestive juice, and it could markedly regulate the gut microbiota composition by increasing the relative abundances of Parabacteroides and Blautia and decreasing the abundance of pathogenic bacteria of Fusobacterium. Additionally, SNA12-EPS improved the ability of gut microbiota to produce short-chain fatty acids.


Asunto(s)
Lactobacillus helveticus , Carbohidratos de la Dieta , Fermentación , Humanos , Peso Molecular , Polisacáridos Bacterianos/química
3.
Carbohydr Polym ; 296: 119994, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-36088015

RESUMEN

Apple xyloglucan (XyG) structural features (molecular weight and building motifs) were studied in relation with the hemicellulose interaction with cellulose nanofiber (CNF) through adsorption isotherm, high performance size exclusion chromatography and high-performance anion exchange chromatography analyses. Up to 75.6 µg of apple XyG adsorbed/mg of CNF. XyG adsorption depended on both Mw and XyG/CNF ratio. The adsorption capacity increased with Mw irrespectively of XyG/CNF ratio. At XyG/CNF ratio > 0.05, the adsorption of high Mw populations (2.0 × 105, 7.9 × 104 g mol-1) gradually ceased, while it kept increasing for low Mw populations (2.6 × 104, 1.2 × 104 g mol-1). The unbranched glucan segments and the galactosylated XLLG motif showed the highest binding affinity to CNF. Most of the XLLG motif was found in "loops and tails", whereas most of the XyG unbranched glucan segments interact directly with CNF.


Asunto(s)
Malus , Nanofibras , Adsorción , Celulosa/química , Glucanos/química , Malus/metabolismo , Peso Molecular , Xilanos
4.
J Drugs Dermatol ; 21(9): 968-973, 2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-36074513

RESUMEN

BACKGROUND: The lips and perioral area play a crucial role in facial aesthetics. Signs of aging, such as wrinkles, decreased muscle tone, and thinning skin, frequently appear first in this anatomical area and, subsequently, in other areas. This may explain why the lips and perioral area are frequently requested focus areas for aesthetic treatments that retain the client’s natural features. AIMS: To assess the safety and efficacy of the rejuvenation of the perioral area with an injectable product containing high-molecular-weight (HMW) native hyaluronic acid (HA) and a cluster of amino acids (AAs). PATIENTS/METHODS: In this open-label observational study, 37 female patients underwent 3 monthly sessions of intradermal injections with HMW HA gel with a cluster of AAs. Follow-up investigations were performed after 30, 60, and 180 days. Outcomes were evaluated subjectively using a patient questionnaire, the Global Aesthetic Improvement Scale (GAIS) questionnaire, and objectively using a 3D photosystem. RESULTS: All patients completed the study. The subjective evaluations made by patients and by the investigator during follow up and at the end of the study were positive, and all patients showed improvement in the perioral area. The objective evaluation showed a statistically significant improvement in pores condition and wrinkles. CONCLUSIONS: The protocol for rejuvenation of the perioral area with injections of HMW HA gel and AA is safe and effective. J Drugs Dermatol. 2022;21(9):968-973.doi:10.36849/JDD.6875.


Asunto(s)
Técnicas Cosméticas , Envejecimiento de la Piel , Aminoácidos/efectos adversos , Técnicas Cosméticas/efectos adversos , Femenino , Humanos , Ácido Hialurónico , Peso Molecular , Satisfacción del Paciente , Rejuvenecimiento , Resultado del Tratamiento
5.
Biomed Pharmacother ; 153: 113417, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36076539

RESUMEN

Fucoidans, sulfated and fucosylated polysaccharides extracted from brown seaweed, were found to inhibit radiotherapy-induced cell damage and fibrosis through the TGF-ß1 pathway. However, the comprehensive molecular response during irradiation-induced fibrosis and fucoidan-assisted recovery still remain unclear. Rat hind limbs were irradiated and smeared with low molecular weight fucoidan (LMF). Protein profiles were examined by a mass spectrometry-based proteomics analysis. Out of a total of 4625 proteins, 233 were found to be significantly up-regulated after irradiation and down-regulated after LMF treatment. Pathway and protein-protein interaction network analyses further indicated that four proteins including Actb, Ezr, Msn and Cdc42 were clustered into the tight junction and regulation of actin cytoskeleton pathways. These four proteins may serve as biomarkers for the detection of skin fibrosis induced by irradiation or TGF-ß1, and for the recovery following LMF treatment.


Asunto(s)
Antineoplásicos , Factor de Crecimiento Transformador beta1 , Animales , Fibrosis , Peso Molecular , Polisacáridos/farmacología , Proteómica , Ratas , Uniones Estrechas
6.
J Phys Chem Lett ; 13(36): 8564-8572, 2022 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-36069730

RESUMEN

Cancer cells secrete extracellular vesicles (EVs) covered with a carbohydrate polymer, hyaluronan (HA), linked to tumor malignancy. Herein, we have unravelled the contour lengths of HA on a single cancer cell-derived EV surface using single-molecule force spectroscopy (SMFS), which divulges the presence of low molecular weight HA (LMW-HA < 200 kDa). We also discovered that these LMW-HA-EVs are significantly more elastic than the normal cell-derived EVs. This intrinsic elasticity of cancer EVs could be directly allied to the LMW-HA abundance and associated labile water network on EV surface as revealed by correlative SMFS, hydration dynamics with fluorescence spectroscopy, and molecular dynamics simulations. This method emerges as a molecular biosensor of the cancer microenvironment.


Asunto(s)
Vesículas Extracelulares , Neoplasias , Humanos , Ácido Hialurónico/química , Peso Molecular , Microambiente Tumoral
7.
Molecules ; 27(17)2022 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-36080221

RESUMEN

Polysaccharide is one of the main components of Codonopsis radix (CR) and has good immune activity. However, the immune activity of CR polysaccharides with different molecular weights has not been systematically screened. In this study, the polysaccharides of CR from Pingshun of Shanxi Province (PSDSs) were first divided into two groups using ultrafiltration: 3.3 kDa (PSDSs-1) and more than 2000 kDa (PSDSs-2). The immunomodulatory effects of PSDSs with different molecular weights were evaluated in vitro and in vivo. In vitro experimental results showed that compared with Lipopolysaccharide-induced macrophages, PSDSs-1 increased TNF-α and IL-6 levels and decreased IL-10. Meanwhile, PSDSs-2 showed the opposite effect, indicating the difference in pro- and anti-inflammatory activities of PSDSs with different molecular weights. The immunosuppressive model of cyclophosphamide proved that PSDSs have immune-promoting function, with PSDSs-1 exhibiting a better effect than PSDSs-2. In vitro and in vivo experiments illustrated the complexity of PSDS immunomodulation. Further research on the functions of PSDs with different molecular weights is needed to lay a foundation for their classification and application.


Asunto(s)
Codonopsis , Inmunomodulación , Peso Molecular , Raíces de Plantas , Polisacáridos/farmacología
8.
Annu Int Conf IEEE Eng Med Biol Soc ; 2022: 3745-3748, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36085632

RESUMEN

Colorectal cancer is the third most incidence cancer world-around. Colonoscopies are the most effective resource to detect and segment abnormal polyp masses, considered as the main biomarker of this cancer. Nonetheless, some recent clinical studies have revealed a polyp miss rate up to 26% during the clinical routine. Also, the expert bias introduced during polyp shape characterization may induce to false-negative diagnosis. Current computational approaches have supported polyp segmentation but over controlled scenarios, where polyp frames have been labeled by an expert. These supervised representations are fully dependent of well-segmented polyps, in crop sequences that always report these masses. This work introduces an attention receptive field mechanism, that robustly recover the polyp shape, by learning non-local pixel relationship. Besides this deep representation is learning from a weakly supervised scheme that includes unlabeled background frames, to discriminate polyps from near structures like intestinal folds. The achieved results outperform state-of-the-art approaches achieving a 95.1% precision in the public CVC-Colon DB, with also competitive performance on other datasets. Clinical relevance-The work address a novel strategy to support segmentation tools in a clinical routine with redundant background over colonoscopy sequences.


Asunto(s)
Pólipos , Atención , Colon , Colonoscopía , Humanos , Peso Molecular
9.
J Agric Food Chem ; 70(36): 11245-11257, 2022 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-36053142

RESUMEN

This study aimed to investigate the effect of different molecular weights on the metabolic characteristics of blackberry polysaccharides (BBP). After degradation, three fractions, namely, BBP-8, BBP-16, and BBP-24, were obtained. During fermentation, all polysaccharide fractions were significantly degraded and utilized by the intestinal microbiota, and the lower-molecular-weight polysaccharides were easier to be fermented with higher gas production and carbohydrate consumption rates. Furthermore, the monosaccharide utilization sequence of all polysaccharides was glucose > galactose > arabinose > galacturonic acid. In addition, the lower-molecular-weight polysaccharides had a faster short-chain fatty acid (SCFA) production rate but did not affect the final SCFA yields. The fermentation of BBP promoted the increase of Bacteroidetes and the decrease of Firmicutes. The proportions of Bacteroidetes in BBP, BBP-8, BBP-16, and BBP-24 were 45.41, 47.50, 48.08, and 50.09%, respectively.


Asunto(s)
Microbioma Gastrointestinal , Rubus , Benzofenonas , Ácidos Borónicos , Ácidos Grasos Volátiles/metabolismo , Fermentación , Peso Molecular , Polisacáridos/metabolismo , Rubus/metabolismo
10.
BMC Musculoskelet Disord ; 23(1): 856, 2022 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-36096771

RESUMEN

BACKGROUND: Intra articular (IA) injection of platelet-rich plasma (PRP) and hyaluronic acid (HA) are of the new methods in the management of hip osteoarthritis (OA). The aim of this study was to compare the effectiveness of IA injections of PRP, HA and their combination in patients with hip OA. HA and PRP are two IA interventions that can be used in OA in the preoperative stages. Due to the different mechanisms of action, these two are proposed to have a synergistic effect by combining. METHODS: This is a randomized clinical trial with three parallel groups. In this study, patients with grade 2 and 3 hip OA were included, and were randomly divided into three injection groups: PRP, HA and PRP + HA. In either group, two injections with 2 weeks' interval were performed into the hip joint under ultrasound guidance. Patients were assessed before the intervention, 2 months and 6 months after the second injection, using the visual analog scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Lequesne questionnaires. RESULTS: One hundred five patients were enrolled randomly in HA, PRP and PRP + HA groups. All three groups showed significant improvement in WOMAC, VAS, and Lequesne at 2 months and 6 months compared with baseline. Comparison of the 3 groups demonstrated significant differences regarding WOMAC and Lequesne total scores and the activities of daily living (ADL) subscale of Lequesne (P = 0.041, 0.001 and 0.002, respectively), in which the observed improvement at 6th month was significantly higher in the PRP + HA and PRP groups compared to the HA group. CONCLUSION: Although all 3 interventions were associated with improvement of pain and function in patients with hip OA, the therapeutic effects of PRP and PRP + HA injections lasted longer (6 months), and the effects of these two interventions on patients' performance, disability, and ADL were superior to HA in the long run. Moreover, the addition of HA to PRP was not associated with a significant increase in the therapeutic results. TRIAL REGISTRATION: The study was registered at Iranian Registry of Clinical Trials (IRCT) website http://www.irct.ir/ , a WHO Primary Register setup, with the registration number of IRCT20130523013442N30 on 29/11/2019.


Asunto(s)
Osteoartritis de la Cadera , Plasma Rico en Plaquetas , Actividades Cotidianas , Humanos , Ácido Hialurónico/uso terapéutico , Inyecciones Intraarticulares , Irán , Peso Molecular , Osteoartritis de la Cadera/tratamiento farmacológico , Osteoartritis de la Cadera/terapia , Resultado del Tratamiento , Ultrasonografía Intervencional
11.
Int J Mol Sci ; 23(15)2022 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-35955592

RESUMEN

In a previous study, we found that administration of ILB®, a new low molecular weight dextran sulphate, significantly improved mitochondrial functions and energy metabolism, as well as decreased oxidative/nitrosative stress, of brain tissue of rats exposed to severe traumatic brain injury (sTBI), induced by the closed-head weight-drop model of diffused TBI. Using aliquots of deproteinized brain tissue of the same animals of this former study, we here determined the concentrations of 24 amino acids of control rats, untreated sTBI rats (sacrificed at 2 and 7 days post-injury) and sTBI rats receiving a subcutaneous ILB® administration (at the dose levels of 1, 5 and 15 mg/kg b.w.) 30 min post-impact (sacrificed at 2 and 7 days post-injury). Additionally, in a different set of experiments, new groups of control rats, untreated sTBI rats and ILB®-treated rats (administered 30 min after sTBI at the dose levels of 1 or 5 mg/kg b.w.) were studied for their neurocognitive functions (anxiety, locomotor capacities, short- and long-term memory) at 7 days after the induction of sTBI. Compared to untreated sTBI animals, ILB® significantly decreased whole brain glutamate (normalizing the glutamate/glutamine ratio), glycine, serine and γ-aminobutyric acid. Furthermore, ILB® administration restored arginine metabolism (preventing nitrosative stress), levels of amino acids involved in methylation reactions (methionine, L-cystathionine, S-adenosylhomocysteine), and N-acetylaspartate homeostasis. The macroscopic evidences of the beneficial effects on brain metabolism induced by ILB® were the relevant improvement in neurocognitive functions of the group of animals treated with ILB® 5 mg/kg b.w., compared to the marked cognitive decline measured in untreated sTBI animals. These results demonstrate that ILB® administration 30 min after sTBI prevents glutamate excitotoxicity and normalizes levels of amino acids involved in crucial brain metabolic functions. The ameliorations of amino acid metabolism, mitochondrial functions and energy metabolism in ILB®-treated rats exposed to sTBI produced significant improvement in neurocognitive functions, reinforcing the concept that ILB® is a new effective therapeutic tool for the treatment of sTBI, worth being tested in the clinical setting.


Asunto(s)
Lesiones Traumáticas del Encéfalo , Sulfatos , Aminoácidos/metabolismo , Animales , Lesiones Traumáticas del Encéfalo/tratamiento farmacológico , Lesiones Traumáticas del Encéfalo/metabolismo , Sulfato de Dextran , Ácido Glutámico , Homeostasis , Peso Molecular , Ratas
12.
Molecules ; 27(15)2022 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-35956840

RESUMEN

Molecular interaction analysis is an essential technique for the study of biomolecular functions and the development of new drugs. Most current methods generally require manipulation to immobilize or label molecules, and require advance identification of at least one of the two molecules in the reaction. In this study, we succeeded in detecting the interaction of low-molecular-weight (LMW) compounds with a membrane protein mixture derived from cultured cells expressing target membrane proteins by using the size exclusion chromatography-mass spectrometry (SEC-MS) method under the condition of 0.001% lauryl maltose neopentyl glycol as detergent and atmospheric pressure chemical ionization. This method allowed us to analyze the interaction of a mixture of medicinal herbal ingredients with a mixture of membrane proteins to identify the two interacting ingredients. As it does not require specialized equipment (e.g., a two-dimensional liquid chromatography system), this SEC-MS method enables the analysis of interactions between LMW compounds and relatively high-expressed membrane proteins without immobilization or derivatization of the molecules.


Asunto(s)
Proteínas de la Membrana , Cromatografía en Gel , Cromatografía Liquida/métodos , Espectrometría de Masas/métodos , Peso Molecular
13.
Soft Matter ; 18(32): 5999-6008, 2022 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-35920399

RESUMEN

Low molecular weight (LMW) supramolecular hydrogels have great potential as next-generation biomaterials for drug delivery, tissue engineering, and regenerative medicine. The design of LMW gelators is complicated by the lack of understanding regarding how the chemical structure of the gelator correlates to self-assembly potential and emergent hydrogel material properties. The fluorenylmethyloxycarbonyl-phenylalanine (Fmoc-Phe) motif is a privileged scaffold that is prone to undergo self-assembly into self-supporting hydrogel networks. Cationic Fmoc-Phe-DAP derivatives modified with diaminopropane (DAP) at the C-terminus have been developed that self-assemble into hydrogel networks in aqueous solutions of sufficient ionic strength. We report herein the impact of side-chain halogenation on the self-assembly and hydrogelation properties of Fmoc-Phe-DAP derivatives. A systematic study of the self-assembly and hydrogelation of monohalogenated Fmoc-Phe-DAP derivatives with F, Cl, or Br atoms in the ortho, meta, or para positions of the phenyl side chain reveal significant differences in self-assembly and gelation potential, nanoscale assembly morphology, and hydrogel viscoelastic properties as a function of halogen identity and substitution position. These results demonstrate the profound impact that subtle changes to the chemical scaffold can have on the behavior of LMW supramolecular gelators and illustrate the ongoing difficulty of predicting the emergent self-assembly and hydrogelation behavior of LMW gelators that differ even modestly in chemical structure.


Asunto(s)
Halógenos , Fenilalanina , Cationes , Hidrogeles/química , Peso Molecular , Fenilalanina/análogos & derivados , Fenilalanina/química
14.
Anal Biochem ; 655: 114848, 2022 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-35948059

RESUMEN

Chondroitin sulfate (CS) of various molecular weight (MW), up to ∼3 kDa, were produced and tested for uronic acid carbazole assay and cetylpyridinium chloride (CPC) titration showing an evident decrease in the assays depending on the CS MW. The described results for uronic acid assay by carbazole reaction and CPC titration of CS poses the problem to know the MW values before their application and to use comparable standards to obtain reliable results. Otherwise, the related quantitative data can be affected by a great error and fake certificate of analysis.


Asunto(s)
Sulfatos de Condroitina , Ácidos Urónicos , Carbazoles , Cetilpiridinio , Glicosaminoglicanos , Ácido Hialurónico , Peso Molecular
15.
Biomacromolecules ; 23(9): 3743-3751, 2022 09 12.
Artículo en Inglés | MEDLINE | ID: mdl-35926160

RESUMEN

Multiangle light scattering (MALS) was used to determine the absolute molar mass of fluorescent macromolecules. It is standard protocol to install bandwidth filters before MALS detectors to suppress detection of fluorescent emissions. Fluorescence can introduce tremendous error in light scattering measurements and is a formidable challenge in accurately characterizing fluorescent macromolecules and particles. However, we show that for some systems, bandwidth filters alone are insufficient for blocking fluorescence in molar mass determinations. For these systems, we have devised a correction procedure to calculate the amount of fluorescence interference in the filtered signal. By determining the intensity of fluorescent emission not blocked by the bandwidth filters, we can correct the filtered signal accordingly and accurately determine the true molar mass. The transmission rates are calculated before MALS experimentation using emission data from standard fluorimetry techniques, allowing for the characterization of unknown samples. To validate the correction procedure, we synthesized fluorescent dye-conjugated proteins using an IR800CW (LI-COR) fluorophore and Bovine Serum Albumin protein. We successfully eliminated fluorescence interference in MALS measurements using this approach. This correction procedure has potential application toward more accurate molar mass characterizations of macromolecules with intrinsic fluorescence, such as lignins, fluorescent proteins, fluorescence-tagged proteins, and optically active nanoparticles.


Asunto(s)
Luz , Nanopartículas , Peso Molecular , Dispersión de Radiación , Albúmina Sérica Bovina
16.
Soft Matter ; 18(36): 6888-6898, 2022 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-36043893

RESUMEN

We propose a possible strategy that may experimentally generate long polymeric chains with an entanglement-free structure. The basic idea is designing the conditions to restrict polymer chains from growing along the surface with an obviously concave curvature. This strategy is proved to effectively reduce the chance of forming both inter- and intra-molecular entanglements, which is quite similar to the self-avoiding random walking of chains on a two dimensional plane. We believe that this kind of chain growth strategy may supply a kind of possible explanation on the formation of the entanglement-free structure of chromosomes, which also have tremendously large molecular weight. Besides, this study also guides experimentalists on synthesizing specific entanglement-free functional polymeric or biological materials.


Asunto(s)
Polímeros , Peso Molecular , Polímeros/química
17.
Biomed Mater ; 17(6)2022 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-36044886

RESUMEN

Hyaluronic acid (HA) hydrogels have been used for a multitude of applications, perhaps most notably for tissue engineering and regenerative medicine, owing to the versatility of the polymer and its tunable nature. Various groups have investigated the impact of hydrogel parameters (e.g. molecular weight, concentration, stiffness, etc)in vitroandin vivoto achieve desired material performance characteristics. A limitation in the literature to date has been that altering one hydrogel parameter (a 'manipulated variable') to achieve a given hydrogel characteristic (a 'controlled variable') changes two variables at a time (e.g. altering molecular weight and/or concentration to investigate cell response to stiffness). Therefore, if cell responses differ, it may be possible that more than one variable caused the changes in observed responses. In the current study, we leveraged thiol-ene click chemistry with a crosslinker to develop a method that minimizes material performance changes and permitted multiple material properties to be independently held constant to evaluate a single variable at a time. Independent control was accomplished by tuning the concentration of crosslinker to achieve an effectively constant stiffness for different HA hydrogel molecular weights and polymer concentrations. Specific formulations were thereby identified that enabled the molecular weight (76-1550 kDa), concentration (2%-10%), or stiffness (∼1-350 kPa) to be varied while the other two were held constant, a key technical achievement. The response of rat mesenchymal stem cells to varying molecular weight, concentration, and stiffness demonstrated consistent upregulation of osteocalcin gene expression. The methodology presented to achieve independent control of hydrogel parameters may potentially be adopted by others for alternative hydrogel polymers, cell types, or cell culture medium compositions to minimize confounding variables in experimental hydrogel designs.


Asunto(s)
Ácido Hialurónico , Hidrogeles , Animales , Condrogénesis , Ácido Hialurónico/química , Hidrogeles/química , Peso Molecular , Polímeros , Ratas
18.
Environ Sci Pollut Res Int ; 29(44): 67418-67429, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35994144

RESUMEN

Implementation of microalgae has been considered for enhancing effluent wastewater quality. However, it can cause environmental issues due to the release of extracellular and algal organic matter in the biological process. This study aimed to investigate the characteristics of dissolved effluent as algae- and bacteria-derived organic matter during the oxidation ditch process. Furthermore, experiments were conducted under three combinations filled by Spirulina platensis, Chlorella vulgaris, and without microalgae. The results showed that dissolved effluent organic matter was more aromatic and hydrophobic than before treatment. Fluorescence spectroscopy identified two components-aromatic protein-like and soluble microbial product-like components-at excitation/emission of 230/345 nm and 320/345 nm after treatment, instead of fulvic acid-like at 230/420 nm and humic acid-like at 320/420 nm in raw wastewater. These components were fractionated based on the average of molecular weight cut-offs (MWCOs), and high (MWCOs > 50,000 Da), medium (MWCOs 50,000-1650 Da), and low molecular weights (MWCOs < 1650 Da) were reported. Biological oxidation ditch under symbiosis algal bacteria generated humic and fulvic acid with a higher MWCOs than the process without algal. The quality and quantity of dissolved effluent organic matter in an oxidation ditch reactor were significantly affected by algal-bacteria symbiotic.


Asunto(s)
Chlorella vulgaris , Aguas Residuales , Colorantes , Materia Orgánica Disuelta , Sustancias Húmicas/análisis , Peso Molecular , Espectrometría de Fluorescencia , Eliminación de Residuos Líquidos/métodos , Aguas Residuales/química
19.
Soft Matter ; 18(35): 6550-6560, 2022 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-36039676

RESUMEN

The α-helix has a significant role in protein function and structure because of its rigidity. In this study, we investigate the persistence length, lp, of α-helical poly-L-lysine, PLL, for two molecular weights. PLL experiences a random coil-helix transition as the pH is raised from 7 to 12. Using light scattering experiments to determine the radius of gyration (Rg), hydrodynamic radius, (Rh), the shape factor (Rg/Rh), and second virial coefficient (A2), and circular dichroism to determine the helical content, we find the structure and lp of PLL as a function of pH (7.4-11.4) and ionic strength (100-166 mM). With increasing pH, we find an increase in lp from 2 nm to 15-21 nm because of α-helix formation. We performed dissipative particle dynamics (DPD) simulations and found a similar increase in lp. While this lp is less than that predicted by molecular dynamics simulations, it is consistent with other experimental results, which quantify the mechanics of α-helices. By determining the mechanics of helical polypeptides like PLL, we can further understand their implications to protein function.


Asunto(s)
Péptidos , Polilisina , Dicroismo Circular , Peso Molecular , Péptidos/química , Polilisina/química , Conformación Proteica en Hélice alfa
20.
Carbohydr Polym ; 295: 119825, 2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-35988993

RESUMEN

Low-molecular-weight heparin (LMWH) is prepared from the controlled chemical or enzymatic depolymerization of animal sourced heparins. It has been widely used as an anticoagulant. Concerns about the shortcomings of animal-derived heparin and the contamination of supply chain demand biochemical approaches for synthesizing LMWH. In the present study, two LMWHs were enzymatically synthesized from low molecular weight N-sulfated heparosan (LMW-NSH) cleaved by recombinant hydrolase, endo-ß-glucuronidase, (HepBp) or heparin lyase III (HepIII), followed by subsequent sulfotransferase modifications. Structural characterization shows that LMWH chains prepared using HepBp had a saturated uronic acid residue at their reducing ends, while chains of LMWH prepared using HepIII had an unsaturated uronic acid residue at their non-reducing end. Both LMWHs had anti-factor Xa and anti-factor IIa activities comparable to enoxaparin. This approach demonstrates that the hydrolase, HepBp, can be used to prepare a new type of LMWH that has no unsaturated uronic acid at its non-reducing end.


Asunto(s)
Glucuronidasa , Heparina de Bajo-Peso-Molecular , Animales , Anticoagulantes/química , Anticoagulantes/farmacología , Disacáridos , Heparina/química , Liasa de Heparina , Heparina de Bajo-Peso-Molecular/química , Peso Molecular , Ácidos Urónicos
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