TY  - JOUR
A1  - Hackethal, Johannes
A1  - Dungel, Peter
A1  - Teuschl, Andreas Herbert
T1  - Frequently Used Strategies to Isolate Extracellular Matrix Proteins from Human Placenta and Adipose Tissue
JF  - Tissue Engineering Part C: Methods
N2  - The natural extracellular matrix (ECM) provides the optimal environment for cells. Many enzymatic or non-enzymatic based strategies to extract ECM proteins from tissues were published over the past years. However, every single isolation strategy reported so far is associated with specific bottlenecks. In this study, frequently used strategies to isolate ECM from human placenta or adipose tissue using Tris-, serum-, or pepsin-based buffers were compared. The resulting ECM proteins were biochemically characterized by analysis of cellular remnants using Hoechst DNA staining, glycosaminoglycan (GAG) content by dimethylmethylene blue, visualization of protein bands using sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis combined with amino acid quantification, and assessment of the proangiogenic profile using an angiogenesis array. Tris-NaCl-extracted ECM proteins showed a high heterogenic degree of extracted proteins, bioactive growth factors, and GAGs, but no collagen-I. Active serum-extracted ECM showed significant lower DNA remnants when compared with the Tris-NaCl isolation strategy. Pepsin-extracted ECM was rich in collagen-I and low amounts of remaining bioactive growth factors. This strategy was most effective to reduce DNA amounts when compared with the other isolation strategies. Pepsin-extracted ECM from both tissues easily gelled at 37°C, whereas the other extracted ECM strategies did not gel at 37°C (Tris-NaCl: liquid; serum: sponge). All relevant characteristics (DNA residues, ECM diversity and bioactivity, shape) of the extracted ECM proteins highly depend on its isolation strategy and could still be optimized. Impact statement The natural human extracellular matrix (ECM) is the ideal cell niche. Various strategies were reported to isolate human ECM components from various sources. In this article, we compared frequently used methods and compared their characteristics (DNA remnants, glycosaminoglycan content, sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, amino acid quantification, angiogenesis array, and gel formation). We conclude that more research is still necessary to optimize current isolation approaches for in vitro or in vivo applications of human ECM.
KW  - Tissue Engineering
KW  - Biomaterials
KW  - Adipose Tissue
KW  - extracellular matrix
KW  - human placenta
Y1  - 
VL  - 27
IS  - 12
SP  - 649
EP  - 660
ER  - 
TY  - JOUR
A1  - Farokhi, Maryam
A1  - Aleemardani, Mina
A1  - Solouk, Atefeh
A1  - Mirzadeh, Hamid
A1  - Teuschl, Andreas Herbert
A1  - Redl, Heinz
T1  - Crosslinking strategies for silk fibroin hydrogels: promising biomedical materials
JF  - Biomedical Materials
N2  - 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 methods enable the formation of three-dimensional (3D) networks under physiological conditions. There are different chemical and physical crosslinking mechanisms available for the generation of SF hydrogels (SFHs). These methods, either chemical or physical, change the structure of SF and improve its mechanical stability, although each method has its advantages and disadvantages. While chemical crosslinking agents guarantee the mechanical strength of SFH through the generation of covalent bonds, they could cause some toxicity, and their usage is not compatible with a cell-friendly technology. On the other hand, physical crosslinking approaches have been implemented in the absence of chemical solvents by the induction of β-sheet conformation in the SF structure. Unfortunately, it is not easy to control the shape and properties of SFHs when using this method. The current review discusses the different crosslinking mechanisms of SFH in detail, in order to support the development of engineered SFHs for biomedical applications.
KW  - Tissue Engineering
KW  - hydrogels
KW  - Biomaterials
KW  - silk fibroin
Y1  - 
VL  - 16
IS  - 2
SP  - 022004
ER  -