Rapid prototyping for tissue-engineered bone scaffold by 3D printing and biocompatibility study

Tissue engineering aims to develop functional substitutes for damaged tissues. Bone scaffolds are critical for guiding cell growth and tissue regeneration. While 3D printing has emerged as a promising fabrication method, its application in bone tissue engineering requires validation of both mechanical and biological performance. Prior research has shown that porous scaffolds can support cell adhesion and proliferation. However, the biocompatibility of 3D-printed bone scaffolds remains an open question. This gap motivated researchers to evaluate both structural and biological properties of a novel scaffold material. The study sought to determine if calcined goat spongy bone-biphasic ceramic composite/PVA gel could serve as a viable scaffold. No prior work had resolved the full set of mechanical and biocompatibility criteria for this specific composite. The need for a scaffold with interconnected pores and strong tensile strength is well established in the field. This study aimed to address these requirements through a 3D printing approach.

The study aimed to develop and assess a 3D-printed bone scaffold made from a composite of calcined goat spongy bone, biphasic ceramic, and PVA gel. The primary goal was to determine whether this scaffold could support rabbit bone marrow stromal cell growth and maintain biocompatibility. Researchers also sought to evaluate the scaffold's mechanical strength and structural porosity. The motivation stemmed from the need for scaffolds that can mimic natural bone architecture while being compatible with living cells. The study focused on whether the scaffold's pore structure and mechanical properties would allow cell adherence and proliferation. By using rabbit BMSCs, the team aimed to model early-stage tissue integration in a controlled environment. The design included in vivo toxicity tests to confirm safety for potential clinical use. This work contributes to the growing field of 3D-printed biomaterials for tissue regeneration.

The scaffold was fabricated using a GXYZ303010-XYLE 3D printing system with gel extrusion. An STL file was pre-designed and imported into the system to guide scaffold geometry. The composite material included calcined goat spongy bone, biphasic ceramic, and PVA gel. After printing, scaffolds were sterilized for cell culture. Rabbit BMSCs were cultured in vitro and then seeded onto the scaffolds. Scanning electron microscopy was used to observe cell adhesion and growth. MTT assays measured cell proliferation and differentiation. Mechanical testing assessed tensile strength using a universal testing machine. For biocompatibility, scaffold leachates were tested in New Zealand rabbits. Cytotoxicity, acute toxicity, pyrogenic, and intracutaneous stimulation tests were conducted. The study combined structural, mechanical, and biological assessments to evaluate scaffold performance.

The 3D-printed scaffold exhibited a porosity of approximately 68.3% with well-connected pores. Mechanical testing showed high tensile strength suitable for bone tissue engineering. SEM imaging confirmed that rabbit BMSCs adhered to and proliferated on the scaffold surface. MTT assays indicated no significant difference in cell proliferation or differentiation compared to control groups. In vivo tests revealed no acute toxicity, pyrogenic reaction, or skin irritation from the scaffold leachates. The scaffold supported cell growth without triggering adverse biological responses. The combination of structural porosity and mechanical strength met the criteria for functional bone scaffolding. These findings suggest that the scaffold is a viable candidate for tissue-engineered bone applications.

The study demonstrated that the 3D-printed bone scaffold supports cell growth and maintains biocompatibility. The scaffold's pore structure and mechanical properties align with requirements for tissue engineering. Rabbit BMSCs adhered to and proliferated on the scaffold without significant differences compared to controls. In vivo tests confirmed no acute toxicity or adverse reactions. These findings suggest that the scaffold is suitable for further development in bone tissue engineering. The study does not propose that the scaffold is essential for all tissue engineering applications but highlights its potential in this specific context. The authors suggest that 3D printing can be a reliable method for scaffold prototyping. The results support the application of this scaffold in future studies focused on bone regeneration.