Continuous Digital Light Processing (cDLP): Highly Accurate Additive Manufacturing of Tissue Engineered Bone...

The design of bone tissue engineering scaffolds requires precise external and internal geometries to ensure proper fit and function. Prior research has shown that scaffold accuracy influences cell loading, nutrient delivery, and scaffold resorption. However, achieving sub-50 μm accuracy remains a challenge in the field. Traditional manufacturing techniques often lack the resolution needed for such applications. This gap motivated the exploration of advanced additive manufacturing methods. Digital fabrication technologies have evolved rapidly in recent years. Yet, their application in biomedical contexts is still limited. The need for high-resolution scaffolds has driven innovation in printing techniques. This paper addresses the challenge of achieving precision in scaffold fabrication.

The aim of this research is to evaluate Continuous Digital Light Processing (cDLP) for fabricating highly accurate bone scaffolds. Bone tissue engineering requires precise control over scaffold architecture. The study investigates whether cDLP can meet the sub-50 μm accuracy threshold. A specific problem is the lack of scalable, high-resolution methods for scaffold fabrication. The motivation stems from the need for better cell loading and nutrient delivery. cDLP offers potential advantages over conventional 3D printing methods. The study also seeks to demonstrate the feasibility of using PPF as a scaffold material. By integrating a photo-crosslinkable polymer and a biocompatible dye, the researchers test the system’s precision.

The study employs Continuous Digital Light Processing (cDLP) for scaffold fabrication. The method uses a DLP chip to control polymerization. A photo-crosslinkable polymer is combined with a photo-initiator and dye. The dye limits light penetration to control polymerization depth. The chosen polymer is poly(propylene fumarate) (PPF), known for its resorbability. Titanium dioxide serves as the biocompatible dye in this setup. Irgacure 819 is used as the photo-initiator to enable crosslinking. Diethyl fumarate is added to manage the material’s viscosity during printing.

The study successfully fabricated scaffolds with sub-50 μm accuracy using cDLP. PPF was selected for its established resorbability in tissue engineering. The integration of titanium dioxide as a dye controlled light penetration. Irgacure 819 facilitated efficient photo-crosslinking of the polymer. Diethyl fumarate adjusted the viscosity for optimal printing conditions. The resulting scaffolds demonstrated high geometrical fidelity. Internal pore structures were accurately rendered for cell loading. The method proved effective in achieving the required precision for bone scaffolds.

The authors propose that cDLP is a viable method for fabricating high-accuracy bone scaffolds. The system achieved sub-50 μm precision, which is critical for scaffold performance. The use of PPF, TiO₂, and Irgacure 819 was validated in this context. The dye’s role in limiting polymerization depth was essential to the process. The study suggests that cDLP can support internal pore loading and nutrient delivery. The method may improve scaffold integration with bioreactor systems. The findings align with the goal of enhancing scaffold accuracy for clinical applications. The researchers emphasize the potential of cDLP in tissue engineering.