Direct inkjet writing type 1 bovine collagen/β-tricalcium phosphate scaffolds for bone regeneration

Bone tissue has the capacity to regenerate under healthy conditions, but complex cases like critically sized defects hinder natural bone regeneration, necessitating surgery, and use of a grafting material for rehabilitation. The field of bone tissue engineering (BTE) has pioneered ways to address such issues utilizing different biomaterials to create a platform for cell migration and tissue formation, leading to improved bone reconstruction. One such approach involves 3D-printed patient-specific scaffolds designed to aid in regeneration of boney defects. This study aimed to develop and characterize 3D printed scaffolds composed of type I collagen augmented with β-tricalcium phosphate (COL/β-TCP). A custom-built direct inkjet write (DIW) printer was used to fabricate β-TCP, COL, and COL/β-TCP scaffolds using synthesized colloidal gels. After chemical crosslinking, the scaffolds were lyophilized and subjected to several characterization techniques, including light microscopy, scanning electron microscopy, and x-ray diffraction to evaluate morphological and chemical properties. In vitro evaluation was performed using human osteoprogenitor cells to assess cytotoxicity and proliferative capacity of the different scaffold types. Characterization results confirmed the presence of β-TCP in the 3D printed COL/β-TCP scaffolds, which exhibited crystals that were attributed to β-TCP due to the presence of calcium and phosphorus, detected through energy dispersive x-ray spectroscopy. In vitro studies showed that the COL/β-TCP scaffolds yielded more favorable results in terms of cell viability and proliferation compared to β-TCP and COL scaffolds. The novel COL/β-TCP scaffold constructs hold promise for improving BTE applications and may offer a superior environment for bone regeneration compared with conventional COL and β-TCP scaffolds.