3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration

Abstract

Low temperature 3D printing of calcium phosphate scaffolds holds great promise for fabricating synthetic bone graft substitutes with enhanced performance over traditional techniques. Many design parameters, such as the binder solution properties, have yet to be optimized to ensure maximal biocompatibility and osteoconductivity with sufficient mechanical properties. This study tailored the phosphoric acid-based binder solution concentration to 8.75 wt% to maximize cytocompatibility and mechanical strength, with a supplementation of Tween 80 to improve printing. To further enhance the formulation, collagen was dissolved into the binder solution to fabricate collagen-calcium phosphate composites. Reducing the viscosity and surface tension through a physiologic heat treatment and Tween 80, respectively, enabled reliable thermal inkjet printing of the collagen solutions. Supplementing the binder solution with 1–2 wt% collagen significantly improved maximum flexural strength and cell viability. To assess the bone healing performance, we implanted 3D printed scaffolds into a critically sized murine femoral defect for 9 weeks. The implants were confirmed to be osteoconductive, with new bone growth incorporating the degrading scaffold materials. In conclusion, this study demonstrates optimization of material parameters for 3D printed calcium phosphate scaffolds and enhancement of material properties by volumetric collagen incorporation via inkjet printing.

Cranial vault reconstruction with bone morphogenetic protein, calcium phosphate, acellular dermal matrix, and calcium alginate in mice

“…However, it is an intensively studied biomaterial with many possibilities of therapeutic indications. Recently, Inzana et al 46 made an experimental 9-week study, in which they have showed bone healing optimization by introducing TCP scaffolds, manufactured in 3-D printers and combined to type-1 collagen.…”

3D printing of hydrogel composite systems: Recent advances in technology for tissue engineering

“…This system can use various materials including ceramic, metals, polymers as well as hydrogels [62][63][64][65] . The process is a 3-step process.…”

Rapid prototyping technology and its application in bone tissue engineering

“…However, the final products usually have weak biomechanical strength, which require high-temperature sintering to obtain structures suitable for bone tissue engineering (Seitz et al, 2005;Lu et al, 2012;Tarafder et al, 2013;Tarafder and Bose, 2014;Qian et al, 2015). Exploration of better binders is currently underway (Inzana et al, 2014). Tarafder and Bose (2014) used 3DP technology to fabricate a TCP scaffold and coated it with alendronate (AD) after sintering.…”