Silk hydrogel for cartilage tissue engineering

Abstract

Cartilage tissue engineering based on cultivation of immature chondrocytes in agarose hydrogel can yield tissue constructs with biomechanical properties comparable to native cartilage. However, agarose is immunogenic and non-degradable, and our capability to modify the structure, composition, and mechanical properties of this material is rather limited. In contrast, silk hydrogel is biocompatible and biodegradable, and it can be produced using a water-based method without organic solvents that enables precise control of structural and mechanical properties in a range of interest for cartilage tissue engineering. We observed that one particular preparation of silk hydrogel yielded cartilaginous constructs with biochemical content and mechanical properties matching constructs based on agarose. This finding and the possibility to vary the properties of silk hydrogel motivated this study of the factors underlying the suitability of hydrogels for cartilage tissue engineering. We present data resulting from a systematic variation of silk hydrogel properties, silk extraction method, gel concentration, and gel structure. Data suggest that silk hydrogel can be used as a tool for studies of the hydrogel-related factors and mechanisms involved in cartilage formation, as well as a tailorable and fully degradable scaffold for cartilage tissue engineering.

Injectable silk-polyethylene glycol hydrogels

“…Pre-formed silk hydrogels prepared by low pH or sonication have been used to repair bone defects in previous studies [7][8][9] Encapsulation and proliferation of human mesenchymal stem cells (hMSCs) in silk hydrogels was achieved over 3 weeks when the gel concentration was lower than 4% (w/v) [4]. In a related study, immature chondrocytes encapsulated in sonication-induced silk hydrogels were used for cartilage tissue engineering [10]. Silk hydrogel was also used to deliver monoclonal antibodies.…”

Supplementation of Exogenous Adenosine 5′-Triphosphate Enhances Mechanical Properties of 3D Cell–Agarose Constructs for Cartilage Tissue Engineering

“…AG was combined with the cell suspension (40 · 10 6 cells/mL) in a 1:1 ratio to result in a seeding density of 20 · 10 6 cells/mL in a 2% w/v AG, which was cast between two glass plates separated by 2.5-mm spacers. After cooling, cylindrical disks (4 mm in diameter · 2.5 mm thick) were cored out using a biopsy punch as in our previous studies 33,35 resulting in 6.2 · 10 5 cells per scaffold.…”

“…For the total collagen content, aliquots were acid hydrolyzed in 12N HCl at 110°C for 16 h, dried over NaOH, and resuspended in an assay buffer (24 mM citric acid monohydrate, 0.012% v/v glacial acetic acid, 85 mM sodium acetate trihydrate, 85 mM sodium hydroxide, pH 6.0). The orthohydroxyproline (OHP) content was determined via a colorimetric assay by reaction with chloramine T and dimethylaminobenzaldehyde 35 that was scaled down for microplates. The OHP content was converted to total collagen content using the 1:7.64 ratio of OHP to collagen.…”

Preparation and physical properties of antheraea yamamai/Bombyx mori silk fibroin blending film

“…B. mori silk fibroin, after dissolved and purified, could be processed into various material formats, such as non-woven mats [2][3][4], hydrogels [5][6][7], films [8][9][10][11], and porous sponges [12][13][14]. The performance of L929 cells on B. mori silk fibroin films was comparable to or better than that of collagen.…”