Fabrication of a Porous Three-Dimensional Scaffold with Interconnected Flow Channels: Co-Cultured Liver Cells and In Vitro Hemocompatibility Assessment

Decellularized extracellular matrix scaffolds: Recent trends and emerging strategies in tissue engineering

The application of scaffolding materials is believed to hold enormous potential for tissue regeneration. Despite the widespread application and rapid advance of several tissue-engineered scaffolds such as natural and synthetic polymer-based scaffolds, they have limited repair capacity due to the difficulties in overcoming the immunogenicity, simulating in-vivo microenvironment, and performing mechanical or biochemical properties similar to native organs/tissues. Fortunately, the emergence of decellularized extracellular matrix (dECM) scaffolds provides an attractive way to overcome these hurdles, which mimic an optimal non-immune environment with native three-dimensional structures and various bioactive components. The consequent cell-seeded construct based on dECM scaffolds, especially stem cell-recellularized construct, is considered an ideal choice for regenerating functional organs/tissues. Herein, we review recent developments in dECM scaffolds and put forward perspectives accordingly, with particular focus on the concept and fabrication of decellularized scaffolds, as well as the application of decellularized scaffolds and their combinations with stem cells (recellularized scaffolds) in tissue engineering, including skin, bone, nerve, heart, along with lung, liver and kidney.

Tissue Engineering 3D Porous Scaffolds Prepared from Electrospun Recombinant Human Collagen (RHC) Polypeptides/Chitosan Nanofibers

Electrospinning, the only method that can continuously produce nanofibers, has been widely used to prepare nanofibers for tissue engineering applications. However, electrospinning is not suitable for preparing clinically relevant three-dimensional (3D) nanofibrous scaffolds with hierarchical pore structures. In this study, recombinant human collagen (RHC)/chitosan nanofibers prepared by electrospinning were combined with porous scaffolds produced by freeze drying to fabricate 3D nanofibrous scaffolds. These scaffolds exhibited high porosity (over 80%) and an interconnected porous structure (ranging from sub-micrometers to 200 μm) covered with nanofibers. As confirmed by the characterization results, these scaffolds showed good swelling ability, stability, and adequate mechanical strength, making it possible to use the 3D nanofibrous scaffolds in various tissue engineering applications. In addition, after seven days of cell culturing, NIH 3T3 was infiltrated into the scaffolds while maintaining its morphology and with superior proliferation and viability. These results indicated that the 3D nanofibrous scaffolds hold great promise for tissue engineering applications.