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1.
Journal of Zhejiang University. Medical sciences ; (6): 285-295, 2023.
Article in English | WPRIM | ID: wpr-982046

ABSTRACT

OBJECTIVES@#To design and prepare silk fibroin/hyaluronic acid composite hydrogel.@*METHODS@#The thiol modified silk fibroin and the double-bond modified hyaluronic acid were rapidly cured into gels through thiol-ene click polymerization under ultraviolet light condition. The grafting rate of modified silk fibroin and hyaluronic acid was characterized by 1H NMR spectroscopy; the gel point and the internal microstructure of hydrogels were characterized by rheological test and scanning electron microscopy; the mechanical properties were characterized by compression test; the swelling rate and degradation rate were determined by mass method. The hydrogel was co-cultured with the cells, the cytotoxicity was measured by the lactate dehydrogenase method, the cell adhesion was measured by the float count method, and the cell growth and differentiation on the surface of the gel were observed by scanning electron microscope and fluorescence microscope.@*RESULTS@#The functional group substitution degrees of modified silk fibroin and hyaluronic acid were 17.99% and 48.03%, respectively. The prepared silk fibroin/hyaluronic acid composite hydrogel had a gel point of 40-60 s and had a porous structure inside the gel. The compressive strength was as high as 450 kPa and it would not break after ten cycles. The water absorption capacity of the composite hydrogel was 4-10 times of its own weight. Degradation experiments showed that the hydrogel was biodegradable, and the degradation rate reached 28%-42% after 35 d. The cell biology experiments showed that the cytotoxicity of the composite gel was low, the cell adhesion was good, and the growth and differentiation of the cells on the surface of the gel were good.@*CONCLUSIONS@#The photocurable silk fibroin/hyaluronic acid composite hydrogel can form a gel quickly, and has excellent mechanical properties, adjustable swelling rate and degradation degree, good biocompatibility, so it has promising application prospects in biomedicine.


Subject(s)
Fibroins/chemistry , Hydrogels/chemistry , Hyaluronic Acid/chemistry , Biocompatible Materials/chemistry , Click Chemistry , Sulfhydryl Compounds , Silk/chemistry
2.
Biol. Res ; 47: 1-10, 2014. graf, tab
Article in English | LILACS | ID: biblio-950711

ABSTRACT

BACKGROUND: Declining immune function poses an important clinical challenge worldwide and supplementation with natural products that possessing immune enhancing properties is a promising approach for preventing or delaying immune function decline. Cocoons from yellow silkworms are a significant source of lutein, and this unexplored silk extract could be a viable alternative source for dietary lutein. This study assessed immunomodulatory activities of the silk lutein extract. Female BALB/c mice orally received lutein, either as silk or marigold extracts (10 or 20 mg/kg daily), or vehicle only (1% tween 80 in PBS pH 7.4) for 4 weeks. Natural killer (NK) cell activity, specific antibody production, lymphocyte subpopulations, mitogen-induced lymphocyte proliferation, and cytokine production were examined. RESULTS: Silk lutein extract increased NK cell activity, and the effect was dose-related whereas marigold lutein extract was ineffective. Silk lutein extract dose-dependently enhanced antibody production in pre-immunized mice but marigold lutein extract had no effect. Feeding with silk lutein extract increased the populations of CD3+ and CD4 + CD3 + cells. Silk lutein extract also stimulated concanavalin A- and lipopolysaccharide-induced proliferations of T and B lymphocytes, respectively. Moreover, silk lutein extract increased IL-2 and IFN-γ production while the effect of marigold lutein extract was undetectable. CONCLUSIONS: Together, silk lutein extract enhanced both innate and adaptive immune functions. This preparation may prove to be an effective supplement for strengthened immunity.


Subject(s)
Animals , Female , Mice , Bombyx/immunology , Tissue Extracts/immunology , Lutein/immunology , Silk/immunology , Animal Shells/chemistry , Immunologic Factors/analysis , Pupa/immunology , Pupa/metabolism , Bombyx/metabolism , Tissue Extracts/pharmacology , Lutein/isolation & purification , Antibodies, Heterophile/blood , Plant Extracts/immunology , B-Lymphocytes/drug effects , Killer Cells, Natural/drug effects , Killer Cells, Natural/immunology , T-Lymphocytes/drug effects , Interleukin-4/analysis , Interferon-gamma/analysis , Interleukin-2/analysis , Interleukin-10/analysis , Tagetes/immunology , Flowers/immunology , Silk/chemistry , Cell Proliferation/drug effects , Flow Cytometry , Mice, Inbred BALB C
3.
Biol. Res ; 46(1): 39-45, 2013. ilus
Article in English | LILACS | ID: lil-676819

ABSTRACT

Carotenoids are efficient antioxidants that are of great importance for human health. Lutein and zeaxanthin are carotinoids present in high concentrations in the human retina which are involved in the photoprotection of the human eye. Lutein may also protect the skin from ultraviolet (UV)-induced damage. The present study investigated the protective effect of lutein extracted from yellow silk cocoons of Bombyx mori on human keratinocytes against UVB irradiation. A human keratinocyte cell line and primary human keratinocytes were used to investigate the UVB protection effects of silk lutein and plant lutein. Silk lutein showed no cytotoxicity to keratinocytes. Treatment with silk lutein prior to UVB irradiation enhanced cell viability and cell proliferation, and reduced cell apoptosis. The protective effects of silk lutein may be superior to those of plant lutein. Silk lutein may have a benefit for protection of keratinocytes against UVB-irradiation.


Subject(s)
Animals , Humans , Male , Keratinocytes/radiation effects , Lutein/pharmacology , Radiation-Protective Agents/pharmacology , Silk/chemistry , Ultraviolet Rays/adverse effects , Apoptosis/drug effects , Apoptosis/radiation effects , Bombyx/metabolism , Cell Line , Cell Proliferation/drug effects , Cell Proliferation/radiation effects , Cell Survival/radiation effects , Foreskin/radiation effects , Lutein/isolation & purification , Primary Cell Culture , Radiation-Protective Agents/isolation & purification
4.
Biol. Res ; 45(1): 45-50, 2012. ilus, tab
Article in English | LILACS | ID: lil-626746

ABSTRACT

Sericin is a silk protein woven from silkworm cocoons (Bombyx mori). In animal model, sericin has been reported to have anti-tumoral action against colon cancer. The mechanisms underlying the activity of sericin against cancer cells are not fully understood. The present study investigated the effects of sericin on human colorectal cancer SW480 cells compared to normal colonic mucosal FHC cells. Since the size of the sericin protein may be important for its activity, two ranges of molecular weight were tested. Sericin was found to decrease SW480 and FHC cell viability. The small sericin had higher anti-proliferative effects than that of the large sericin in both cell types. Increased apoptosis of SW480 cells is associated with increased caspase-3 activity and decreased Bcl-2 expression. The anti-proliferative effect of sericin was accompanied by cell cycle arrest at the S phase. Thus, sericin reduced SW480 cell viability by inducing cell apoptosis via caspase-3 activation and down-regulation of Bcl-2 expression. The present study provides scientific data that support the protective effect of silk sericin against cancer cells of the colon and suggests that this protein may have significant health benefits and could potentially be developed as a dietary supplement for colon cancer prevention.


Subject(s)
Animals , Cattle , Humans , Apoptosis/drug effects , Cell Proliferation/drug effects , Colon/drug effects , Colonic Neoplasms/pathology , Sericins/pharmacology , Silk/chemistry , Bombyx , Cell Line, Tumor , Cell Survival , Colon/cytology , Colonic Neoplasms/metabolism , Colonic Neoplasms/prevention & control , Intestinal Mucosa/cytology , Intestinal Mucosa/drug effects , Molecular Weight , Sericins/chemistry
5.
Journal of Huazhong University of Science and Technology (Medical Sciences) ; (6): 80-3, 2009.
Article in English | WPRIM | ID: wpr-635058

ABSTRACT

In order to investigate the effect of Arg-Gly-Asp (RGD) peptide-modified silk biomaterial on the adhesion and proliferation of bone marrow-derived mesenchymal stem cells (MSCs), MSCs of third generation were seeded onto the surface of RGD-decorated silk (silk-RGD group), silk alone (silk group) or tissue culture plate (TCP group). After incubation for 4 or 12 h, MSCs were examined quantitatively by using precipitation method for cell attachment. The cell proliferation, which was defined as cell density, was compared among the three groups after culture for 1, 2, 3, and 4 days. Cell skeleton, which was labeled fluorescently, was observed under laser confocal microscope after 24 h of culture. The results showed that cell adhesion rate in silk-RGD group was higher than in silk group (P0.05). There were no significant differences in the cell proliferation among the three groups at different time points (P>0.05 for all). Laser confocal microscopy revealed that in silk-RGD group, MSCs, strongly fluorescently stained, spread fully, with stress fibers clearly seen, while in silk group, actin filaments were sparsely aligned and less stress fibers were found. It was concluded that RGD peptide could improve the adhesion of MSCs to the silk scaffold, but had no impact on the proliferation of the cells.


Subject(s)
Biocompatible Materials/chemistry , Bone Marrow Cells/cytology , Cell Adhesion/drug effects , Cell Proliferation/drug effects , Mesenchymal Stem Cells/cytology , Oligopeptides/chemistry , Silk/chemistry , Tissue Scaffolds
6.
J Biosci ; 2007 Jun; 32(4): 705-12
Article in English | IMSEAR | ID: sea-110770

ABSTRACT

A cDNA coding for the C-terminus of spider flagelliform silk protein (AvFlag) was cloned from Araneus ventricosus. Analysis of the cDNA sequence shows that the C-terminus of AvFlag consists of 167 amino acids of a repetitive region and 87 amino acids of a C-terminal non-repetitive region. The peptide motifs found in spider flagelliform silk proteins, GPGGX and GGX,were conserved in the repetitive region of AvFlag. Phylogenetic analysis further confirmed that AvFlag belongs to the spider flagelliform silk proteins. The AvFlag cDNA was expressed as a 28 kDa polypeptide in baculovirus-infected insect cells. As a new expression approach for spider silk protein,the combination of polyhedrin and AvFlag creates a polyhedrin AvFlag fusion protein (61 kDa) that is produced as recombinant polyhedra; this provides a basis for the source of spider silk proteins for various applications.


Subject(s)
Amino Acid Sequence , Animals , Baculoviridae/genetics , Base Sequence , Blotting, Western , Cloning, Molecular , DNA, Complementary , Electrophoresis, Polyacrylamide Gel , Insect Proteins/chemistry , Molecular Sequence Data , Phylogeny , Sequence Homology, Amino Acid , Silk/chemistry , Spiders
7.
J Biosci ; 2005 Mar; 30(2): 259-68
Article in English | IMSEAR | ID: sea-111104

ABSTRACT

We have carried out crystal structure analysis of raw pure Mysore silk fibers belonging to Bombyx mori on the basis of model parameters of Marsh et al using Linked-Atom-Least-Squares technique. The intensity of all the reflections were computed employing CCP13 software. We observe that the molecular modification is essentially same as b-pleated structure with antipolar-antiparallel arrangements formed by hydrogen bonds. The essential differences observed in the structure are highlighted and discussed.


Subject(s)
Amino Acid Sequence , Animals , Bombyx/chemistry , Crystallography , India , Models, Molecular , Molecular Sequence Data , Peptides/genetics , Silk/chemistry , X-Ray Diffraction
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