Search results for "Fibroin"

Functionality of endothelial cells on silk fibroin nets: Comparative study of micro- and nanometric fibre size

2007

Biomimetic material design, such as mimicking nanostructured components of the extracellular matrix, is an actual challenge for biomaterial research with a high impact on tissue engineering and regenerative medicine. Thus, understanding the cellular response at the cell biological and molecular level and the consequences of various chemically or physically modified biomaterials is highly important. In the present study we assessed the response of human umbilical vein endothelial cells (HUVEC) and outgrowth endothelial cells (OEC) from endothelial progenitor cells to different variants of nanofibrous silk fibroin nets in comparison to microfibrous silk fibroin scaffolds with regard to cellul…

Methionine in a protein hydrophobic core drives tight interactions required for assembly of spider silk

2019

Web spiders connect silk proteins, so-called spidroins, into fibers of extraordinary toughness. The spidroin N-terminal domain (NTD) plays a pivotal role in this process: it polymerizes spidroins through a complex mechanism of dimerization. Here we analyze sequences of spidroin NTDs and find an unusually high content of the amino acid methionine. We simultaneously mutate all methionines present in the hydrophobic core of a spidroin NTD from a nursery web spider’s dragline silk to leucine. The mutated NTD is strongly stabilized and folds at the theoretical speed limit. The structure of the mutant is preserved, yet its ability to dimerize is substantially impaired. We find that side chains of…

Interpenetrating composite biomaterials of hyaluronic acid derivatives and silk fibroin

2014

Composizione per uso nella finitura, conservazione, restauro di manufatti

2017

L’invenzione è relativa ad una composizione per il consolidamento e la conservazione di fibre tessili basata sull’impiego di un nano materiale in associazione con un agente di supporto. Il nano materiale è la nano fibroina e il materiale di supporto è preferenzialmente il chitosano, ma si possono impiegare altri materiali di analoghe prestazioni. La composizione trova applicazione nell’ambito della conservazione e restauro di materiali tessili, in quanto permette la riparazione di fibre e tessuti danneggiati, ripristinando le proprietà meccaniche, e la protezione da processi foto-ossidativi dei manufatti tessili in generale. Ulteriore campo di applicazione è quello del finissaggio di fibre …

High-yield Production of Amyloid-β Peptide Enabled by a Customized Spider Silk Domain

2020

AbstractDuring storage in the silk gland, the N-terminal domain (NT) of spider silk proteins (spidroins) keeps the aggregation-prone repetitive region in solution at extreme concentrations. We observe that NTs from different spidroins have co-evolved with their respective repeat region, and now use an NT that is distantly related to previously used NTs, for efficient recombinant production of the amyloid-β peptide (Aβ) implicated in Alzheimer’s disease. A designed variant of NT from Nephila clavipes flagelliform spidroin, which in nature allows production and storage of β-hairpin repeat segments, gives exceptionally high yields of different human Aβ variants as a solubility tag. This tool e…

Non-cross-linked porcine-based collagen I-III membranes do not require high vascularization rates for their integration within the implantation bed: …

2012

There are conflicting reports concerning the tissue reaction of small animals to porcine-based, non-cross-linked collagen I-III membranes/matrices for use in guided tissue/bone regeneration. The fast degradation of these membranes/matrices combined with transmembrane vascularization within 4 weeks has been observed in rats compared with the slow vascularization and continuous integration observed in mice. The aim of the present study was to analyze the tissue reaction to a porcine-based non-cross-linked collagen I-III membrane in mice. Using a subcutaneous implantation model, the membrane was implanted subcutaneously in mice for up to 60 days. The extent of scaffold vascularization, tissue …

Modified Silk with Cell-Adhesive and Non-Thrombogenic Properties as a Tissue Engineering Substrate

2016

IntroductionReplacement of damaged tissue is nowadays an aim of tissue engineering. This technique involves the use of porous or fibrous structures – the so-called scaffolds – that support the colonization with the desired cell type and which are degraded after fulfilling their temporary supporting function. Basic requirements for the prevailing materials used in this field are nontoxicity, low immunogenicity and cell-adhesiveness. Furthermore blood-contacting devices should exhibit low thrombogenicity.The biopolymer silk, mainly consisiting of the protein silk fibroin, matches some of these criteria but bare silk does not facilitate cellular adhesion and growth and unfortunately the materi…

Silk fibroin scaffolds enhance cell commitment of adult rat cardiac progenitor cells.

2015

The use of three-dimensional (3D) cultures may induce cardiac progenitor cells to synthesize their own extracellular matrix (ECM) and sarcomeric proteins to initiate cardiac differentiation. 3D cultures grown on synthetic scaffolds may favour the implantation and survival of stem cells for cell therapy when pharmacological therapies are not efficient in curing cardiovascular diseases and when organ transplantation remains the only treatment able to rescue the patient’s life. Silk fibroin-based scaffolds may be used to increase cell affinity to biomaterials and may be chemically modified to improve cell adhesion. In the present study, porous, partially orientated and electrospun nanometric n…

The rapid anastomosis between prevascularized networks on silk fibroin scaffolds generated in vitro with cocultures of human microvascular endothelia…

2010

The survival and functioning of a bone biomaterial upon implantation requires a rapidly forming and stably functioning vascularization that connects the implant to the recipient. We have previously shown that human microcapillary endothelial cells (HDMEC) and primary human osteoblast cells (HOS) in coculture on various 3-D bone biomaterial scaffolds rapidly distribute and self-assemble into a morphological structure resembling bone tissue. Endothelial cells form microcapillary-like structures containing a lumen and these were intertwined between the osteoblast cells and the biomaterial. This tissue-like self-assembly occurred in the absence of exogenously added angiogenic stimuli or artific…

Dynamic processes involved in the pre-vascularization of silk fibroin constructs for bone regeneration using outgrowth endothelial cells

2009

For successful bone regeneration tissue engineered bone constructs combining both aspects, namely a high osteogenic potential and a rapid connection to the vascular network are needed. In this study we assessed the formation of pre-vascular structures by human outgrowth endothelial cells (OEC) from progenitors in the peripheral blood and the osteogenic differentiation of primary human osteoblasts (pOB) on micrometric silk fibroin scaffolds. The rational was to gain more insight into the dynamic processes involved in the differentiation and functionality of both cell types depending on culture time in vitro. Vascular tube formation by OEC was assessed quantitatively at one and 4 weeks of cul…