Decellularized ECMs

Lung Provides oxygen and ejqiels carbon dioxide Asthma Pulmonary edema Decellularized ECM TRPV 4 blockers... 

Tissue engineering strategies using decellularized ECM products... 

Other natural polymers Decellularized ECM, chitosan, gelatin, and keratin. 

Apart from fibrin, collagen, and alginate, other natural polymers that have shown promising results in vivo are chitosan, Matrigel, hyaluronic acid, and decellularized ECM [14]. For example, Fujita et al. showed efficient angiogenesis and collateral flow induced by FGF-2 loaded in chitosan HGs. Notably, the chitosan HG allowed an extended FGF-2 delivery for more than 1 month [76]. Moreover, chitosan HGs combined with stem cells also resulted in increased angiogenesis, reduced adverse remodeling and preserved heart function compared to free cells or nonloaded chitosan HG administration [77]. 

Natural polymers of recombinant or natural fibronectin, laminin, vitronectin, and collagen IV, which are components of ECMs, have begun to be used instead of Matrigel or decellularized ECMs for the feeder-free growth of undifferentiated hPSCs because their chemical characteristics are relatively more well defined (Table 6.1). The ECM components that are immobilized on dishes for hPSC proliferation and to provide binding sites for stem cells are summarized in Table 6.4 [50]. 

Initially, natural decellularized arterial (ECM) was previously used as a scaffold however, this material was found to form matrices too tight for cellular migration when seeded with cells (36). To create more porous scaffolds, pure elastin and pure collagen scaffolds derived from arterial ECM were generated. The elastin scaffolds exhibited 120 pm infiltration of fibroblast cells in vitro and in vivo models showed improved cell infiltration and repopulation of the scaffold... 

Cell-derived ECM has been coated on scaffolds to enhance the biocompatibility and osteoconductive properties of tissue-engineered scaffolds for bone repair (Decaris et al., 2012a Sadr et al., 2012 Pati et al., 2014). Cells are seeded on scaffolds to allow them to proliferate with or without osteogenic supplements, and then decellularization is performed, followed by the study of the reseeded cell behaviors on this ECM/scaf-fold construct and the evolution of bone healing in vivo. Numerous studies showed that cell expansion and differentiation capacities were significantly improved by... 

The key to the successful clinical application for hard tissue repair using the ECM-derived tissues is the preservation of bioactive factors and the elimination of any immunogenic substance remained in the source tissue during the decellularization or demineralized procedures. However, the current acellular methods normally cause loss of bioactive factors and/or the destruction of the ultrastructure due to the extreme conditions experienced during the process (Zimmermann and Moghaddam, 2011 Badylak et al., 2011). Therefore, further optimization of the ECM scaffolds is required in the following studies so as to ensure the safety and effectiveness of these promising scaffolds. 

Acellular nerve matrix allografts have also been observed as useful biomaterials for nerve regeneration [34]. These allografts preserve extracellular matrix (ECM) components and, therefore, mimic the ECM of peripheral nerves mechanically and physically. In this way, acellular nerve matrices aid in the reconstruction of the peripheral nerve. However, decellularization techniques, such as thermal deceUularization, can damage the ECM structure and fail to extract all cellular components leading to inflammation upon implantation [35]. 

ECM-derived molecules (eg, collagen, laminin, fibrin, fibronectin, andhyaluronan) instead of decellularized allografts are also used. For instance. Neurotube, NeuroGen,... 

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