Silk fibroin-polyurethane scaffolds for tissue engineering

Biomedicine & Pharmacotherapy, 2021

Silk fibroin is a protein with intrinsic characteristics that make it a good candidate as a scaffold for tissue engineering. Recent works have enhanced its benefits by adding inorganic phases that interact with silk fibroin in different ways. A systematic review was performed in four databases to study the physicochemical and biological performance of silk fibroin nanocomposites. In the last decade, only 51 articles contained either in vitro cell culture models or in vivo tests. The analysis of such works resulted in their classification into the following scaffold types: particles, mats and textiles, films, hydrogels, sponge-like structures, and mixed conformations. From the physicochemical perspective, the inorganic phase imbued in silk fibroin nanocomposites resulted in better stability and mechanical performance. This review revealed that the inorganic phase may be associated with specific biological responses, such as neovascularisation, cell differentiation, cell proliferation, and antimicrobial and immunomodulatory activity. The study of nanocomposites as tissue engineering scaffolds is a highly active area mostly focused on bone and cartilage regeneration with promising results. Nonetheless, there are still many challenges related to their application in other tissues, a better understanding of the interaction between the inorganic and organic phases, and the associated biological response.

Journal of Materials Science: Materials in Medicine, 2000

In order to develop scaffolds with improved biocompatibility for cell culture, hybrid scaffolds were fabricated by modifying poly(e-caprolactone) (PCL) with silk ®broin (SF) in a porous structure. Scanning electronic microscopy revealed that the morphology of the PCL±SF hybrid scaffold was affected by the concentration of the SF solution. Availability of SF on the surface and the conformational transition induced by methanol treatment were proved by attenuated total re¯ection Fourier transformed infrared spectroscopy (ATR±FTIR), and wettability of the hybrid scaffold was greatly improved. To evaluate scaffold biocompatibility, human ®broblasts were cultured on the hybrid scaffold with the unmodi®ed PCL scaffold as control. An MTT assay indicated that although fewer cells were initially held on the hybrid scaffold after one day of culture, comparable cell numbers were achieved after four days and signi®cantly more cells proliferated on the hybrid after seven days. The cell morphology also indicated that the PCL±SF hybrid scaffold was favorable for cell culture. This study suggests that surface modi®cation with SF would be an effective way to improve the biocompatibility of PCL, facilitating its application in practical tissue engineering.

Acta Biomaterialia, 2014

The development of porous scaffolds for tissue engineering applications requires the careful choice of properties, as these influence cell adhesion, proliferation and differentiation. Sterilization of scaffolds is a prerequisite for in vitro culture as well as for subsequent in vivo implantation. The variety of methods used to provide sterility is as diverse as the possible effects they can have on the structural and material properties of the three-dimensional (3-D) porous structure, especially in polymeric or proteinous scaffold materials. Silk fibroin (SF) has previously been demonstrated to offer exceptional benefits over conventional synthetic and natural biomaterials in generating scaffolds for tissue replacements. This study sought to determine the effect of sterilization methods, such as autoclaving, heat-, ethylene oxide-, ethanol-or antibiotic-antimycotic treatment, on porous 3-D SF scaffolds. In terms of scaffold morphology, topography, crystallinity and short-term cell viability, the different sterilization methods showed only few effects. Nevertheless, mechanical properties were significantly decreased by a factor of two by all methods except for dry autoclaving, which seemed not to affect mechanical properties compared to the native control group. These data suggest that SF scaffolds are in general highly resistant to various sterilization treatments. Nevertheless, care should be taken if initial mechanical properties are of interest.

2019

Regeneration of diseased or damaged tissues is one of the challenges in tissue engineering. Although there have been many methods developed, scaffold-based tissue engineering provides both biological and functional environment for regeneration. In last decade, Silk fibroin has gained immense importance for applications in tissue engineering scaffolding. It is a fibrous protein extracted from cocoons of Bombyx mori and spiders. It has been used as a biomaterial for tissue engineering owing to its unique mechanical properties, controllable biodegradation rate and biocompatibility. This review discusses about properties of silk fibroin and recent application with advancement of silk fibroin as a biomaterial in various tissue engineering approaches.

Macromolecular Bioscience, 2005

while the new treatment proposed could really dialogue with the cells. Its non-homogeneous surface can explain the existence of cells spreading in specific directions and the presence of cell repellent areas even 4 d after seeding.

Biomaterials, 2008

Surface properties of implanted biomaterials can cause fibrotic tissue reactions by stimulating differentiation of host fibroblasts into contractile myofibroblasts. Silk fibroin (SF) protein has been used as biomaterial in pure and blended form. however, its effect on myofibroblast differentiation remains elusive. We here conjugated SF with lactose using cyanuric chloride as coupling spacer. NMR spectroscopy and the conjugates ability to agglomerate Abrus precatorius agglutinin verified efficient conjugation. Two-dimensional films and three-dimensional scaffolds produced from pure and lactose-conjugated SF solutions were tested as culture substrates for subcutaneous fibroblasts and myofibroblasts. Lactoseconjugated SF substrates mediated higher adhesion, proliferation and viability of fibroblastic cells than pure SF. This SF film composition promotes better attachment of fibroblasts than myofibroblasts. Profibrotic cytokine TGFb1 was ineffective in inducing fibroblast-to-myofibroblast differentiation on such substrates. Pre-differentiated myofibroblasts lost their contractile phenotype within a few days of being cultured on lactose-conjugated SF. Myofibroblast differentiation was also suppressed by growth in threedimensional lactose-conjugated SF scaffolds that, however, support population with fibroblasts. We propose that this biomaterial will promote tissue integration without causing a fibrotic host reaction.

Biomolecules

Hydrogel with chemical modification has been used for 3D printing in the biomedical field of cell and tissue-based regeneration because it provides a good cellular microenvironment and mechanical supportive ability. As a scaffold and a matrix, hydrogel itself has to be modified chemically and physically to form a β-sheet crosslinking structure for the strength of the biomaterials. These chemical modifications could affect the biological damage done to encapsulated cells or surrounding tissues due to unreacted chemical residues. Biological assessment, including assessment of the cytocompatibility of hydrogel in clinical trials, must involve testing with cytotoxicity, irritation, and sensitization. Here, we modified silk fibroin and glycidyl methacrylate (Silk-GMA) and evaluated the physical characterizations, residual chemical detection, and the biological effect of residual GMA depending on dialysis periods. Silk-GMA depending on each dialysis period had a typical β-sheet structure ...

Bioengineering, 2024

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

2011

Silk fibroin has been successfully used as a biomaterial for tissue regeneration. In order to prepare silk fibroin biomaterials for human implantation a series of processing steps are required to purify the protein. Degumming to remove inflammatory sericin is a crucial step related to biocompatibility and variability in the material. Detailed characterization of silk fibroin degumming is reported. The degumming conditions significantly affected cell viability on the silk fibroin material and the ability to form three-dimensional porous scaffolds from the silk fibroin, but did not affect macrophage activation or β-sheet content in the materials formed. Methods are also provided to determine the content of residual sericin in silk fibroin solutions and to assess changes in silk fibroin molecular weight. Amino acid composition analysis was used to detect sericin residuals in silk solutions with a detection limit between 1.0% and 10% wt/wt, while fluorescence spectroscopy was used to reproducibly distinguish between silk samples with different molecular weights. Both methods are simple and require minimal sample volume, providing useful quality control tools for silk fibroin preparation processes.

Polymers, 2019

In this study, a coating from electrospun silk fibroin was performed with the aim to modify the surface of breast implants. We evaluated the effect of fibroin on polymeric matrices of poly (ethylene oxide) (PEO) to enhance cell viability, adhesion, and proliferation of HaCaT human keratinocytes to enhance the healing process on breast prosthesis implantation. We electrospun six blends of fibroin and PEO at different concentrations. These scaffolds were characterized by scanning electron microscopy, contact angle measurements, ATR-FTIR spectroscopy, and X-ray diffraction. We obtained diverse network conformations at different combinations to examine the regulation of cell adhesion and proliferation by modifying the microstructure of the matrix to be applied as a potential scaffold for coating breast implants. The key contribution of this work is the solution it provides to enhance the healing process on prosthesis implantation considering that the use of these PEO–fibroin scaffolds r...