Evaluation of methods for the construction of collagenous scaffolds with a radial pore structure for tissue engineering

Abstract

Type I collagen is used widely as a biomaterial. The structure of collagenous biomaterials, including pore sizes and general architecture, can be varied by a number of techniques. In this study, we developed a method to construct flat fibrillar type I collagen scaffolds, 6 cm in diameter and with a radially orientated pore structure, by the use of directional freezing. Different methodologies were tested, the optimal one being freezing of a collagen suspension inside-out, using a centrally positioned liquid nitrogen-cooled tube. Pore sizes could be varied by the use of different tube materials. Use of aluminium tubes resulted in radial scaffolds with a pore size of 20-30 µm, whereas use of stainless steel produced radial scaffolds with 70-100 µm pore sizes. Brass- and copper-based tubes produced scaffolds with less homogeneous radial pores, pore sizes being 90-100 and 50-80 µm, respectively. Fibreglass tubes gave even less uniformity (pore size 100-150 µm). Scaffolds were free of cracks, except in case of aluminium. Scaffolds with a radial inner structure may be especially suitable for tissue engineering of organs with a radial scaffold structure, such as the diaphragm.

Radially oriented collagen scaffold with SDF-1 promotes osteochondral repair by facilitating cell homing

“…Conforming to our expectations, the radially oriented structure exhibited a predetermined 3-D shape, as well as suitable porosity and micromechanical properties. Brouwer and colleagues designed a twolayered collagenous scaffold with a radial pore structure for repair of the diaphragm, and found that cells infiltrate further into the center of the scaffold [24,39]. This is consistent with our results that BMSCs were recruited into the radially oriented scaffold.…”

Delivery of stromal cell-derived factor 1α for in situ tissue regeneration

“…They found that cells infiltrated further into the center of the scaffold. Besides, Brouwer and his colleagues also designed a scaffold with radial pore structure to repair the diaphragm defects, and reached the same conclusion [92, 93]. The in vivo experiments on rabbits confirmed that BMSCs could also be recruited into the radially-oriented scaffold with the assistance of SDF-1α.…”

Nanotopography of collagen thin films in correlation with fibroblast response

“…It is also important for tissue tensile strength and for forming a functional scaffold for cells. 14 Because of its unique characteristics, 15 collagen is widely used as a biomaterial, scaffold, and culture substrate for cell and tissue regeneration. 10 Type I collagen plays an essential part in the regulation of cellular behavior.…”