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1.
Particular attention has been given to axonal outgrowth of neurons to understand how topographical surface cues influence attachment and subsequent directional migration and growth. In present study, the silk fibroin (SF) scaffold with uniaxial channels was prepared by directional freeze-drying processes. The average pore diameter, the porosity, and pore density of the scaffold are 120 µm, 88 %, and 203 mm?2, respectively. Further, hippocampal neurons were seeded onto the scaffold and the hippocampal neurons morphology was investigated. Cell-cell networks and cell-matrix interactions had been established by newly formed axons and the diversity of neurons was much higher after culturing 7 days. The neurons expressed β-III-tubulin and nerve filament, while glial fibrillary acidic protein immunofluorescence was barely above background. These results indicated that the SF scaffolds with uniaxial multichannels could be guided axons of neurons spread along the channels. SF scaffolds with oriented pores have a potential for nerve tissue regeneration.  相似文献   

2.
Cartilage repair is a challenge in bone tissue reconstruction. In this study, silk fibroin (SF), chondroitin sulfate (CS) and hyaluronic acid (HA) were employed to fabricate scaffolds for tissue engineered cartilage by freeze drying technique. The secondary pores were formed in the main pores of SF/CS/HA scaffold which improved the pore connectivity and equilibrium swelling of the scaffold. Furthermore, rat bone marrow mesenchymal stem cells were seeded on the scaffolds to evaluate the cell adhesion and proliferation. Results of hematoxylin/eosin staining and cell counting kit-8 assay showed that the cells migration and differentiation of SF/CS/HA (80/15/5) scaffold were better than that of SF/CS/HA scaffolds with different ratios after 7 days culture. Moreover, immunohistochemistry and scanning electron microscope demonstrated that large amounts of collagen II and proteoglycans of the cells were expressed in the SF/CS/HA 3D scaffold, while the expression of collagen I was barely visible by immunohistochemistry. Abound of extracellular matrix was formed to morphologically round and distributed uniformly throughout the scaffolds. The 3D ternary scaffold could promote the cells chondrogenic differentiation without using any inductive agent and offer potential for cartilage tissue regeneration.  相似文献   

3.
Herein we report successful synthesis of silk fibroin (SF) three dimensional scaffolds (SF 3D-scaffold) from SF sponge and SF nanofibers. Both the nanofibers and sponge were prepared from Bombyx mori fibroin. The SF 3D-scaffold was prepared by electrospinning the fibroin nanofibers over the sponge. Surface morphology was determined by scanning electron microscopy (SEM), while nanofiber diameter and pore size were measured using imageJ software. Effect of spinning time on the pore size and cell adhesion was determined. Average diameter of the SF nanofibers was measured to be 320 nm and pore size was found to reduce with increasing spinning time, such that, for 1 h spinning time pore size was 231 µm and the same for 3.5 h was 4.1 µm. However, the number of pores increased with spinning time. The results confirmed adhesion of MC3T3-E1 cells on the SF sponge, SF nanofibers and SF three dimensional scaffolds. Higher cell adhesion was found on the three dimensional scaffold in comparison to the nanofibers and sponge, possibly due to highly porous structure with very small and numerous pores in the resultant composite; hence more cell adhesion sites. The cell adhesion result confirmed biocompatibility of the SF 3D-scaffold and hence its suitability for applications in tissue engineering.  相似文献   

4.
The use of silk protein as a biomaterial has been studied for decades. In this study, silk fibroin (SF)/hyaluronic acid (HA) blend scaffolds were prepared by freeze-drying technique. The structure and properties of the blend scaffolds were examined and analyzed. The results demonstrated that the secondary structures of the SF/HA scaffolds were mainly amorphous and β-sheet structures. The pore radius and porosity of the scaffolds decreased with a decrease in the freezing temperature decrease and an increase in the HA ratio. The pore radius and porosity were regulated from 32.22 μm to 290.76 μm and from 74.1 % to 91.15 %, respectively. In vitro, the SF/HA scaffolds could support the fibroblast cell adhesion and proliferation and showed good cytocompatibility. In vivo, the SF/HA scaffolds were implanted into the dorsum of Sprague Dawley rats to evaluate their bioactivity for dermal tissue reconstruction. The vascular-like structures appeared more rapidly in SF/HA scaffolds than that in the PVA group, and a new dermal layer was formed, as determined by histological analysis. The SF/HA porous scaffolds have promise as a dermal substitute.  相似文献   

5.
The aim of this study was to compare physical, mechanical and biological properties of 3-dimensional scaffolds prepared from Bombyx mori silk fibroin (SF), fibroin blended with collagen (SF/C), and fibroin blended with gelatin (SF/G) using a freeze-drying technique. The prepared scaffolds were sponge-like structure that exhibited homogeneous porosity with highly interconnected pores. Average pore size of these scaffolds ranged from 65–147 μm. All biodegradable scaffolds were capable of water absorption of 90 %. The degradation behavior of these scaffolds could be controlled by varying the amount of blended polymer. The SF/C and SF/G scaffolds showed higher compressive modulus than that of SF scaffolds which could be attributed to the thicker pore wall observed in the blended constructs. The less crystalline SF structure was observed in SF/G scaffolds as compared to SF/C scaffolds. Thus, the highest compressive modulus was observed on SF/C matrix. To investigate the feasibility of the scaffolds for cartilage tissue engineering application, rat articular chondrocytes were seeded onto the scaffolds. The MTT assay demonstrated that blending collagen or gelatin into SF sponge facilitated cell attachment and proliferation better than SF scaffolds. The blended SF scaffolds possessed superior physical, mechanical and biological properties in comparison to SF scaffolds and showed high potential for application in cartilage tissue engineering.  相似文献   

6.
Protein and polysaccharide was the most important extracellular matrix in dermal tissue. In this study, Silk fibroin (SF) / hyaluronic acid (HA) blend films mimicking the dermal tissue components were prepared and investigated. The results indicated that HA and SF has a good miscibility, HA interfered with SF to form crystal structure. By using EDC as cross-linker, effective cross-linking function on SF and HA macromolecules was reacted, the water solubility of the blend films decreased obviously after being cross-linked by EDC. The existence of EDC could promote SF to form Silk I structure. L929 cells were seeded on these blend films and showed normal attachment morphology. Cell-matrix interactions established by newly formed extracellular matrix were observed after 5 days in culture. The MTT assay showed that cell proliferation on the SF/HA blend films were enhanced significantly compared with that on the SF and HA films. These new 2D SF/HA blend films provided a favorable microenvironment for the proliferation of L929 cells and hold a potential for dermal tissue regeneration.  相似文献   

7.
The present study reports the preparation of a cellulose scaffold for tissue engineering directly from cellulose fiber using ionic liquid (IL) by the NaCl leaching method with bovine serum albumin (BSA), which is well known protein utilized for biomedical applications like degradation of polymer, cell attachment and proliferation on scaffold. The 1-n-allyl-3-methylimidazolium chloride (AmimCl) IL was used as a solvent for cellulose. The morphology of the scaffold was studied by scanning electron microscopy (SEM) and the images showed that the pore sizes of the scaffolds were about 200 µm. In addition, the water uptake (WU) and degree of degradation of the cellulose scaffold were measured. Meanwhile, the biocompatibility and bioactivity of the scaffold were determined via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenytetrazolium bromide (MTT) assay and the Live/Dead viability test. The various results demonstrated the ability of the Mesenchymal stem cells (MSC) to attach to the surface of the scaffolds amplified as percentage of BSA increased in cellulose scaffold.  相似文献   

8.

Background

The aim of this study was to fabricate the poly caprolactone (PCL) aligned nanofiber scaffold and to evaluate the survival, adhesion, proliferation, and differentiation of rat hair follicle stem cells (HFSC) in the graft material using electrospun PCL nanofiber scaffold for tissue engineering applications.

Methods

The bulge region of rat whisker was isolated and cultured in DMEM: nutrient mixture F-12 supplemented with epidermal growth factor. The morphological and biological features of cultured bulge cells were observed by light microscopy using immunocytochemistry methods. Electrospinning was used for production of PCL nanofiber scaffolds. Scanning electron microscopy (SEM), 3-(4, 5-di-methylthiazol- 2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, and histology analysis were used to investigate the cell morphology, viability, attachment and infiltration of the HFSC on the PCL nanofiber scaffolds.

Results

The results of the MTT assay showed cell viability and cell proliferation of the HFSC on PCL nanofiber scaffolds. SEM microscopy images indicated that HFSC are attached, proliferated and spread on PCL nanofiber scaffolds. Also, immunocytochemical analysis showed cell infiltration and cell differentiation on the scaffolds.

Conclusion

The results of this study reveal that PCL nanofiber scaffolds are suitable for cell culture, proliferation, differentiation and attachment. Furthermore, HFSC are attached and proliferated on PCL nanofiber scaffolds.Key Words: Nanofiber, Electrospinning, Stem cells, Tissue engineering  相似文献   

9.
We studied the key characteristics of a novel silk yarn reeled from fresh cocoons. Compared with traditional silk yarn, this novel silk yarn displayed better mechanical properties, especially in terms of a higher breaking stress and toughness, and exhibited a different surface morphology. A cross-sectional observation and the sericin content results illustrated that different sericin coatings on the silk yarn reeled from fresh cocoons surface did not improve the mechanical properties. The degumming and tensile testing analysis indicated that degummed silk fibroin of novel silk yarn is able to resist deformation and fracture better than silk fibroin of traditional silk yarn. The FTIR results revealed that the selected techniques is an important contributor to the silk fibroin mechanical properties, because novel technique brought higher percentage beta-sheet structures in novel silk yarn fibroin than traditional silk yarn. The new technique that using novel silk yarn has improved its mechanical properties and it is expected that the silk yarn with superior mechanical properties could be used in fabrics transistors, electrodes and reinforced biomaterials.  相似文献   

10.
In this study, to improve the cellular biocompatibility of PVP-PCL micro- and nanofiber scaffold, a novel electrospun collagen/PVP-PCL micro- and nanofiber scaffold was sucessfully prepared assisted by ultrasonic irradiation using chloroform/ethanol mixtures as solvent. The micro- and nanofibers of the electrospun PCL-PVP scaffolds still presented compact inter-fiber entanglement and three-dimensional netlike network with some certain range of pore space after introducing collagen. The incorporated collagen phase was dispersed as inclusions within the electrospun fibers, and then could be easily released by immersing the scaffold in Hanks simulated body fluid. Meanwhile, the integral triple helix structure of collagen could be maintained after blending with the PVP-PCL mixture due to the weak intermolecular interactions. Furthermore, the suitable mechanical and degradation properties of the PVP-PCL scaffold were still reserved after introducing collagen, and the introduction of collagen could further promote the thermostability of the PVP-PCL scaffold. Above all, the collagen/PVP-PCL scaffold showed no cytotoxicity, better cell proliferation, and improved viability of primary fibroblasts than the PVP-PCL scaffold. In conclusion, blending collagen with the PVP-PCL mixture in this study has potential for promoting the biocompatibility of PVP-PCL micro- and nanofiber scaffolds for tissue engineering.  相似文献   

11.
In this study, a three-dimensional (3D) poly(lactide-co-glycolide) (PLGA) microfibrous scaffold with high porosity (ca. 90 % porosity) was developed for evaluating its performance in tissue engineering application. A dope solution of PLGA/polyethylene oxide (PEO) blend was electrospun into a methanol coagulation bath for fabricating highly porous 3D PLGA scaffold and a salt leaching method was used for making interconnected pores of 100?C200 ??m size inside the scaffold. The morphological structure, pore size and porosity of the microfibrous scaffold were determined, and compared with twodimensional (2D) mat-type and 3D sponge-type of PLGA scaffold. Also, swelling ratio, water uptake and compressive strength were compared in order to elucidate the structure-property relationships of different types of the scaffolds, especially in a wet condition. As a result of scanning electron microscopy (SEM) observation, normal human dermal fibroblasts (nHDF) were migrated, attached, and proliferated well inside the 3D scaffold. MTT assay confirmed that the highly porous 3D PLGA microfibrous scaffold had superior cell adhesion and proliferation abilities due to fibrous structure of large specific surface area, and interconnected pore structure. Therefore, this high performance 3D PLGA scaffold can have a high potentiality for application in tissue engineering in comparison with conventional PLGA scaffolds.  相似文献   

12.
Electrospinning has been recognized as an efficient technique for the fabrication of neural tissue engineering scaffolds. Many approaches have been developed on material optimization, electrospinning techniques, and physical properties of scaffolds to produce a suitable scaffold for tissue engineering aspects. In this study, structural properties of scaffolds were promoted by controlling the speed of fiber collection without any post-processing. PLGA scaffolds, in two significantly different solution concentrations, were fabricated by the electrospinning process to produce scaffolds with the optimum nerve cell growth in a desired direction. The minimum, intermediate and maximum rate of fiber collection (0.4, 2.4, 4.8 m/s) formed Random, Aligned and Drown-aligned fibers, with various porosities and hydrophilicities. The scaffolds were characterized by fiber diameter, porosity, water contact angle and morphology. Human nerve cells were cultured on fiber substrates for seven days to study the effects of different scaffold structures on cell morphology and proliferation, simultaneously. The results of MTT assay, the morphology of cells and scaffold characterization recommend that the best structure to promote cell direction, morphology and proliferation is accessible in an optimized hydrophilicity and porosity of scaffolds, which was obtained at the collector linear speed of 2.4 m/s.  相似文献   

13.
We successfully prepared optically transparent silk fibroin-cellulose nanofiber (CN) composite films from solvent casting using a stable CN suspension in an aqueous silk fibroin solution. The transmittance of the silk fibroin composite films was observed by a UV-visible spectrophotometer. The secondary structural change of the silk fibroin caused by the incorporation of CNs was characterized using Fourier transform infrared spectroscopy. A tensile test was carried out to investigate the mechanical properties. The results showed that the composite film exhibited visible-light transmittance of 75 %, and its mechanical strength and Young’s modulus were increased by 44 % and 35 %, respectively, as compared to a neat silk fibroin film.  相似文献   

14.
Ultra fine fibers were electrospun from regenerated silk fibroin/formic acid solution. Effect of some process parameters on the morphology, diameter and variation in fiber diameter of electrospun fibers were experimentally investigated. Scanning electron microscope was used for the measurement of fiber diameter. Fibers with diameter ranging from 80 to 210 nm were collected depending on the solution concentration and the applied voltages. Response surface methodology (RSM) was used to obtain a quantitative relationship between selected electrospinning parameters and the average fiber diameters and its distribution. It was shown that concentration of silk fibroin solution had a significant effect on the fiber diameter and the standard deviation of the fiber diameter. Applied voltage had no significant effect on the fiber diameter and its standard deviation.  相似文献   

15.
Consolidation of fragile historic silks is of great importance for further displays and researches. An effective and convenient method to consolidate aged silk fabric has been proposed by using a silk fibroin (SF)/ethylene glycol diglycidyl ether (EGDE) consolidation system. Artificial aged silk fabrics treated with SF/EGDE show great improvement in mechanical properties. The chemical reaction between EGDE and silk fabrics has been proved in previous paper. And in this paper, mechanical test, field emission scanning electron microscopy (FESEM), Fourier transform infrared spectrum (FTIR) test and amino acid analysis (AAA) were applied to illustrate the interactions between SF and silk fabric, EGDE and SF. Results show that SF takes part in the consolidation in the form of adhesions on the surface of silk fibers. The chemical reactions and film adhesion are both responsible for the improvements of mechanical properties in the consolidation.  相似文献   

16.
Presently, tissue engineering is employed in the restoration and repair of tissue defects. Degradable scaffolds, stem cells and stimulating factors are employed in this method. In this study, the effect of melanocyte-stimulating hormone (MSH) and/or hydroxyapatite (HA) on proliferation, osteoblast differentiation, and mineralization of human dental pulp stem cells (hDPSCs) seeded on PLLA-PCL nanofibrous scaffolds was evaluated. For this aim, PLLA-PCL-HA nanofibrous scaffolds were fabricated using electrospinning method. FE-SEM images exhibited that all nanofibers had bead-free morphologies with average diameters ranging from 150–205 nm. Human DPSCs seeded into PLLA-PCL nanofibers were treated with MSH. Cell viability, proliferation, morphology, osteogenic potential, and the expression of tissue-specific genes were assessed by means of MTT assay, FE-SEM, alizarin red S staining, and RT-PCR analysis. hDPSCs exhibited improved adhesion and proliferation capacity on the PLLA-PCL-HA nanofibers treated with MSH compared to other groups (p<0.05). Additionally, PLLA-PCL-HA nanofibers treated with MSH exhibited significantly higher mineralization and alkaline phosphatase activity than other groups. RT-PCR results confirmed that PLLA-PCL-HA nanofibers enriched with MSH could significantly unregulated the gene expression of BMP2, osteocalcin, RUNX2 and DSPP that correlated to osteogenic differentiation (p<0.05). Based on results, incorporation of HA nanoparticles in PLLA-PCL nanofibers and addition of MSH in media exhibited synergistic effects on the adhesion, proliferation, and osteogenesis differentiation of hDPSCs, and therefore assumed to be a favorable scaffold for bone tissue engineering applications.  相似文献   

17.
Chromophore incorporated into the protein chains through residue modification on silk fibroin will be an important way to get new dyeing technology with improved color fastness. Herein, 1-aminoanthraquinone diazonium salt was prepared and used for the modified dyeing on tyrosine of silk fibroin. The silk after modified dyeing was measured by UV-Vis, FTIR, MS, 1H-NMR, Data color, and other testing techniques. Interestingly, the resulting silk showed excellent rub and wash fastness. The enhanced color fastness is contributed by an electrophilic substitution reaction between 1- aminoanthraquinone diazonium salt and the ortho position of phenolic hydroxyl in tyrosine molecular. Moreover, the mechanical property of silk was protected effectively by the mild coupling modified dyeing, better than the traditional acid dyeing under high temperature for a long time. This facile strategy provides an alternative approach to silk dyeing and benefits the silk applications.  相似文献   

18.
This article focuses on elucidating the key presentation features of neurotrophic ligands at polymer interfaces. Different biointerfacial configurations of the human neural cell adhesion molecule L1 were established on two-dimensional films and three-dimensional fibrous scaffolds of synthetic tyrosine-derived polycarbonate polymers and probed for surface concentrations, microscale organization, and effects on cultured primary neurons and neural stem cells. Underlying polymer substrates were modified with varying combinations of protein A and poly-D-lysine to modulate the immobilization and presentation of the Fc fusion fragment of the extracellular domain of L1 (L1-Fc). When presented as an oriented and multimeric configuration from protein A-pretreated polymers, L1-Fc significantly increased neurite outgrowth of rodent spinal cord neurons and cerebellar neurons as early as 24 h compared to the traditional presentation via adsorption onto surfaces treated with poly-D-lysine. Cultures of human neural progenitor cells screened on the L1-Fc/polymer biointerfaces showed significantly enhanced neuronal differentiation and neuritogenesis on all protein A oriented substrates. Notably, the highest degree of βIII-tubulin expression for cells in 3-D fibrous scaffolds were observed in protein A oriented substrates with PDL pretreatment, suggesting combined effects of cell attachment to polycationic charged substrates with subcellular topography along with L1-mediated adhesion mediating neuronal differentiation. Together, these findings highlight the promise of displays of multimeric neural adhesion ligands via biointerfacially engineered substrates to "cooperatively" enhance neuronal phenotypes on polymers of relevance to tissue engineering.  相似文献   

19.
During enzymatic modifications of silk fibroins, the accessibility of tyrosinases to the reactive sites was limited owing to the steric hindrance of tyrosine residues in the fibroin proteins. To improve the reactivity of silk fibroin, a tyrosine-containing peptide (TyrP) was covalently grafted onto the fibroin surfaces using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). Enzymatic oxidation of the modified fibroins was subsequently carried out with a mushroom tyrosinase, followed by coupling of ε-polylysine (ε-PL) with the generated o-quinone residues of silk fibroins. The efficacy of grafting reaction was examined by means of SDS-PAGE and amine acid analysis. The results indicated EDC treatment might cause the direct self-crosslinks of silk fibroins and TyrP-bridged cross-links of fibroin molecules as well, which led to a noticeable increase in the molecular weight of fibroin proteins. TyrP-grafted fibroins displayed higher reactivity compared to the untreated, and more ε-PL was bonded to the fibroin surfaces when incubating with tyrosinase, resulting in improved wettability and mechanical property. The presented work offers an efficient alternative for the enzymatic modification of the fibroin-based materials with tyrosinase.  相似文献   

20.
Over the last few years, significant research has been conducted in the construction of artificial bone scaffolds. In the present study, different types of polymer scaffolds, such as chitosan-alginate (Chi-Alg) and chitosan-alginate with fucoidan (Chi-Alg-fucoidan), were developed by a freeze-drying method, and each was characterized as a bone graft substitute. The porosity, water uptake and retention ability of the prepared scaffolds showed similar efficacy. The pore size of the Chi-Alg and Chi-Alg-fucoidan scaffolds were measured from scanning electron microscopy and found to be 62–490 and 56–437 µm, respectively. In vitro studies using the MG-63 cell line revealed profound cytocompatibility, increased cell proliferation and enhanced alkaline phosphatase secretion in the Chi-Alg-fucoidan scaffold compared to the Chi-Alg scaffold. Further, protein adsorption and mineralization were about two times greater in the Chi-Alg-fucoidan scaffold than the Chi-Alg scaffold. Hence, we suggest that Chi-Alg-fucoidan will be a promising biomaterial for bone tissue regeneration.  相似文献   

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