Abstract
BACKGROUND: Bone defects still pose various challenges in osteology. As one of the treatment options for bone defects, bone tissue engineering requires biomaterials with good biocompatibility and seed cells with good differentiation capacity. This study aimed to fabricate a 3D-printed polylactic acid and hydroxyapatite (PLA/HA) composite scaffold with urine-derived stem cells (USCs) to study its therapeutic effect in a model of skull defect in rats.METHODS: USCs, isolated and extracted from the urine of healthy adult males, were inoculated onto a 3D-printed PLA/HA composite scaffold and a PLA scaffold. Skull defect model rats were randomly divided into three groups (control, PLA, and PLA/HA). Twelve weeks after implanting scaffolds containing USCs into rats with a skull defect, the therapeutic efficacy was evaluated by real-time PCR, micro-CT, histology, and immunohistochemistry.RESULTS: The 3D-printed PLA/HA composite scaffold had good mechanical properties and porosity. The adhesion and proliferation of USCs on scaffolds also demonstrated excellent biocompatibility. PLA and PLA/HA containing USCs promoted bone regeneration in the defect area, supported by the general observation and CT images at 12 weeks after treatment, with coverage of 74.6%±1.9% and 96.7%±1.6%, respectively. Immunohistochemical staining showed a progressive process of new bone formation on PLA/HA scaffolds containing USCs at the defect site compared to that in PLA and control groups.CONCLUSION: The 3D-printed PLA/HA composite scaffold with USCs was successfully applied to the skull defect in rats. Under the linkage of the scaffold, the proliferation, differentiation, and osteogenesis expression of USCs were promoted near the bone defect area. These findings demonstrated broad application prospects of PLA/HA scaffolds with USCs in bone tissue engineering.
Development of 3D-printed PLGA/TiO2 nanocomposite scaffolds for bone tissue engineering applications