Although three-dimensional fibroin scaffolds have been prepared with freeze drying method, the porosity and pore sizes still can not satisfy the requirement of tissue engineering. In this article, fibroin porous scaffold with high porosity and > 100μm diameter interconnected pores was firstly prepared with freeze drying method through adjusting fibroin concentration. The morphology of different scaffolds lyophilized from different fibroin concentration was observed by SEM. A novel freeze drying ...
Last. Yu-li Wang(UMMS: University of Massachusetts Medical School)H-Index: 76
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The ability of cells to form tissues represents one of the most fundamental issues in biology. However, it is unclear what triggers cells to adhere to one another in tissues and to migrate once a piece of tissue is planted on culture surfaces. Using substrates of identical chemical composition but different flexibility, we show that this process is controlled by substrate rigidity: on stiff substrates, cells migrate away from one another and spread on surfaces, whereas on soft substrates they me...
Novel protein blends have been prepared by mixing gelatin (G) with Bombyx mori silk fibroin (SF) and using aqueous methanol (MeOH) to post-induce SF crystallization. When co-cast from solution, amorphous blends of these polymers appear homogeneous, as discerned from visual observation, microscopy, and Fourier-transform infrared (FTIR) spectroscopy. Upon subsequent exposure to aqueous MeOH, SF undergoes a conformational change from random coil to β sheet. This transformation occurs in pure SF, as...
Last. Fuzhai Cui(THU: Tsinghua University)H-Index: 75
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Abstract Although three-dimensional fibroin scaffolds have been prepared with freeze–drying method, these scaffolds still cannot meet the requirements of tissue engineering. In this article, a new process is described to form fibroin-based porous scaffolds with controllable structure and morphological features. When collagen was added to fibroin solution, the viscosity of the blend solution increased because of the interaction between fibroin and collagen, and then it restrained the unwanted fib...
Polypropyleneimine octaamine dendrimers were studied as an alternative means of generating highly crosslinked collagen. Crosslinking was effected by using the water-soluble carbodiimide 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC). The multifunctional dendrimers were introduced as novel crosslinkers after the activation of the carboxylic acid groups of glutamic and aspartic acid residues in collagen. The conventional crosslinker glutaraldehyde was used as a control. EDC, i...
Last. Luigi Nicolais(University of Naples Federico II)H-Index: 70
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Abstract Hydrogels with good mechanical stability are generally obtained by chemical crosslinking. However, the compounds used as crosslinking agents are often highly toxic, and thus they are not recommended as starting materials in view of an environmentally safe production process and a biocompatible product. In this work chemically crosslinked superabsorbent hydrogels have been synthesized from water solutions of hydroxyethylcellulose (HEC), carboxymethylcellulose sodium salt (CMCNa) and hyal...
#2Paul A. Janmey(UPenn: University of Pennsylvania)H-Index: 119
Last. Yu-li Wang(UMMS: University of Massachusetts Medical School)H-Index: 76
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Normal tissue cells are generally not viable when suspended in a fluid and are therefore said to be anchorage dependent. Such cells must adhere to a solid, but a solid can be as rigid as glass or softer than a baby9s skin. The behavior of some cells on soft materials is characteristic of important phenotypes; for example, cell growth on soft agar gels is used to identify cancer cells. However, an understanding of how tissue cells—including fibroblasts, myocytes, neurons, and other cell types—sen...
#1Hou-rong Xiao(USTC: University of Science and Technology of China)H-Index: 1
#2Yongshu Xie(USTC: University of Science and Technology of China)H-Index: 9
Last. Chunhua Shi(USTC: University of Science and Technology of China)H-Index: 7
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Abstract A novel copper-containing enzyme named COI (catechol oxidase I) has been isolated and purified from tobacco by extracting acetone-emerged powder with phosphate buffer, centrifugation at low temperature, ammonium sulfate fractional precipitation, and column chromatography on DEAE-sephadex (A-50), sephadex (G-75), and DEAE-celluse (DE-52). PAGE, SDS-PAGE were used to detect the enzyme purity, and to determine its molecular weight. Then the secondary structures of COI at different pH, diff...
Mixed protein-based hydrogels have been prepared by blending gelatin (G) with amorphous Bombyx mori silk fibroin (SF) and promoting β-crystallization of SF via subsequent exposure to methanol or methanol/water solutions. The introduction of β crystals in SF serves to stabilize the hydrogel network and extend the solidlike behavior of these thermally responsive materials to elevated temperatures beyond the helix→coil (h→c) transition of G. In this work, we investigate the swelling and protein rel...
Structural properties of a bacterial luciferase mutant, evolved by random mutagenesis, have been investigated. Bacte- rial luciferases (LuxAB) can be readily classed as slow or fast decay luciferases based on their rates of luminescence decay in a single turnover assay. By random mutagenesis, one of the mutants generated by a single mutation on LuxA at position 175 (E175G) resulted in the ''slow decay'' Xenorhabdus lumines- cens luciferase was converted into a luciferase with a significantly mor...
Due to their strong biomimetic potential, silk fibroin (SF) hydrogels are impressive candidates for tissue engineering, due to their tunable mechanical properties, biocompatibility, low immunotoxicity, controllable biodegradability, and a remarkable capacity for biomaterial modification and the realization of a specific molecular structure. The fundamental chemical and physical structure of SF allows its structure to be altered using various crosslinking strategies. The established crosslinking ...
#2Baoqi Zuo(Soochow University (Suzhou))H-Index: 19
Over the past decade, the hydrogels prepared from silk fibroin have received immense research attention due to the advantages of safe nature, biocompatibility, controllable degradation and capability to combine with other materials. They have broad application prospects in biomedicine and other fields. However, the traditional silk protein hydrogels have a simple network structure and single functionality, thus, leading to poor adaptability towards complex application environments. As a result, ...
Last. Hongbing Deng(WHU: Wuhan University)H-Index: 40
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Abstract Silk fibroin (SF) is increasingly needed in tissue engineering for its superior biocompatibility. However, the practical applications of pure SF biomaterials confront bacterial infection problems. In this study, chitosan (CS) and polydopamine (PDA) were introduced into electrospun nanofibrous SF mats through layer-by-layer self-assembly (LBL) to obtain enhanced antibacterial ability and cytocompatibility. The surface morphology and composition analysis confirmed the successful depositio...
The junction between the epithelium and the underlying connective tissue undulates, constituting of rete ridges, which lack currently available soft tissue constructs. In this study, using a micro electro mechanical systems process and soft lithography, fifteen negative molds, with different dimensions and aspect ratios in grid- and pillar-type configurations, were designed and fabricated to create three-dimensional micropatterns and replicated onto fish-scale type I collagen scaffolds treated w...
Last. Mh Busra Fauzi(UKM: National University of Malaysia)H-Index: 8
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The use of hybridisation strategy in biomaterials technology provides a powerful synergistic effect as a functional matrix. Silk fibroin (SF) has been widely used for drug delivery, and collagen (Col) resembles the extracellular matrix (ECM). This systematic review was performed to scrutinise the outcome of hybrid Col and SF for cutaneous wound healing. This paper reviewed the progress of related research based on in vitro and in vivo studies and the influence of the physicochemical properties o...
Last. Xinyu Wang(WUT: Wuhan University of Technology)H-Index: 18
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Abstract In this study, silk fibroin (SF)/sodium alginate (SA) porous materials (PMs) with different blend ratios were generated using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) as crosslinking agent by a simple freeze-dried method. Degradation experiment of SF/SA PMs have been systematically investigated up to 18 days in Collagenase IA solution at 37 °C, Phosphate buffer saline (PBS) solution without enzyme was used as a control. The results showed SF/SA 50/50 PMs exhibited a lowest r...
The Hydrogels are tunable three dimensional polymer network attractive for their rich hydrophilicity along with structural similarity with the extracellular matrix that provide a cell proliferation and facilitate rapid cell to cell communication. These Hydrogels are largely focussed by many researchers in the field of medicine due to its capacity to act as scaffold for tissue regeneration, as injectable Hydrogel for sustained drug delivery, in encapsulation of the enzymes and many more. These ar...
Last. Xinyu Wang(WUT: Wuhan University of Technology)H-Index: 18
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In this study, in order to obtain hydrogels with good properties for sustained release of hydrophobic drugs or for tissue engineering, poly(vinyl alcohol) (PVA)/silk fibroin (SF) semi-interpenetrating (semi-IPN) hydrogels with varied ratios of PVA/SF were enzymatically cross-linked using horseradish peroxidase. A vial inversion test determined approximate gelation times of PVA/SF hydrogels ranging from 5 to 10 min. The hydrogels with varied ratios showed differences in pore size and morphology. ...
Abstract In materials science and engineering, designed and well-ordered self-assembled hydrogel with excellent biocompatibility and nontoxic properties is an inviting issue. In this study, a novel self-assembled sericin hydrogel was prepared by a simple-two-step process containing milling and high temperature and high pressure. It is worthwhile pointing out that the sericin with high extraction rate (95%) for fabricating sericin hydrogel was isolated from fibroin-deficient mutant silk cocoons. ...
