Rapid biofabrication of tubular tissue constructs by centrifugal casting in a decellularized natural scaffold with laser-machined micropores

Abstract

Centrifugal casting allows rapid biofabrication of tubular tissue constructs by suspending living cells in an in situ cross-linkable hydrogel. We hypothesize that introduction of laser-machined micropores into a decellularized natural scaffold will facilitate cell seeding by centrifugal casting and increase hydrogel retention, without compromising the biomechanical properties of the scaffold. Micropores with diameters of 50, 100, and 200 mum were machined at different linear densities in decellularized small intestine submucosa (SIS) planar sheets and tubular SIS scaffolds using an argon laser. The ultimate stress and ultimate strain values for SIS sheets with laser-machined micropores with diameter 50 mum and distance between holes as low as 714 mum were not significantly different from unmachined control SIS specimens. Centrifugal casting of GFP-labeled cells suspended in an in situ cross-linkable hyaluronan-based hydrogel resulted in scaffold recellularization with a high density of viable cells inside the laser-machined micropores. Perfusion tests demonstrated the retention of the cells encapsulated within the HA hydrogel in the microholes. Thus, an SIS scaffold with appropriately sized microholes can be loaded with hydrogel encapsulated cells by centrifugal casting to give a mechanically robust construct that retains the cell-seeded hydrogel, permitting rapid biofabrication of tubular tissue construct in a "bioreactor-free" fashion.

Mechanical characterization of a customized decellularized scaffold for vascular tissue engineering

“…If this goal can be achieved the probability of translating the technology to clinical application will be significantly improved. Attempts have been made to overcome this problem within synthetic scaffolds for vascular applications using rotational vacuum techniques (Soletti et al, 2006, Nieponice et al, 2008, Kasyanov et al, 2009, Godbey et al, 2004, the high porosity and large pore size make these scaffolds easier to seed with large cell numbers in short time periods. While in the case of dense decellularized tissue bulk seeding the medial layer has not been successfully achieved.…”

Photocrosslinkable Hyaluronan-Gelatin Hydrogels for Two-Step Bioprinting

“…Once a tubular structure can be built, most other biological structures are attainable, as they are comprised of a combination of tubular or hollow structures and simpler cell arrangements. 14,15 A major hurdle has been that few biomaterials have been developed with design criteria specific to bioprinting.…”

“…[19][20][21][22][23][24][25][26] The ease with which 3D tissue culture can be performed in vitro and in vivo has made this biomaterial appropriate for new tissue engineering research applications such as development of bladder tissues, centrifugally cast vessel-like tubes, and tumor xenograft models for drug and discovery. 14,18,[27][28][29][30][31][32] Despite these many applications, however, the polyethylene glycol diacrylate (PEGDA)-crosslinked thiolated HA-based sECMs were found to be unsuitable for bioprinting. Because they could not maintain structural integrity during printing and would frequently clog the print heads, a new crosslinking chemistry was needed.…”

Towards organ printing: engineering an intra-organ branched vascular tree

“…Finally, the effective reendothelization of a complete intra-organ vascular system remains to be demonstrated. It has however been demonstrated that introduction of laser-machined micropores helps to improve recellularization of natural-scaffold-derived vascular grafts and enhances its vascularization after implantation [17]. How this technology can be adapted to thick 3D decellularized whole organ scaffolds remains to be seen.…”