Composite bacterial cellulose–psoralen– polycaprolactone scaffold for enhanced bone regeneration and infection prevention in open bone defects

Abstract

This study aimed to improve the treatment of open bone defects by developing a hybrid scaffold that enhances bone regeneration and prevents infections. Polycaprolactone (PCL) scaffolds were incorporated for mechanical support, while bacterial cellulose (BC) membranes facilitated psoralen (Pso) delivery. PCL scaffolds were fabricated via three-dimensional (3D) printing, and BC was extracted from fungi to prepare three types of scaffolds as follows: PCL, BC–PCL, and BC–Pso–PCL. The scaffolds were characterized through scanning electron microscopy, contact angle measurement, and infrared spectroscopy. Biocompatibility was assessed by cytotoxicity (CCK-8) assay, cell migration assay, live/dead cell staining, and cell proliferation experiments. Antibacterial effects were tested under a simulated bacterial environment. Osteogenic performance was evaluated by alkaline phosphatase (ALP) activity, Alizarin red staining (ARS), and immunofluorescence after osteogenic induction. Quantitative reverse transcriptase PCR (qRT-PCR) and Western blotting were performed to analyze bone regeneration and angiogenesis markers. Bone regeneration efficacy was assessed in vivo using a 5 mm critical-sized cranial bone defect model in rats. Biocompatibility studies demonstrated that all three scaffolds showed good biocompatibility. BC–Pso–PCL scaffold effectively inhibited Staphylococcus aureus growth. The ALP staining and ARS following osteogenic induction indicated that the BC–Pso–PCL group exhibited superior ALP activity and mineralized nodule formation compared to other groups. Subsequent immunofluorescence, qRT-PCR, and Western blot further confirmed the superior osteogenic performance of the BC–Pso–PCL scaffold. In vivo experiments demonstrated that the BC–Pso–PCL scaffold achieved the highest level of new bone formation in rat cranial defects. In conclusion, the BC–Pso–PCL scaffold demonstrated superior biocompatibility in cytotoxicity, cell migration, live/dead staining, and proliferation assays, while also promoting bone regeneration and angiogenesis. The in vivo study further confirmed its superior potential in bone formation. These findings highlight the BC–Pso– PCL hybrid scaffold as a promising implantable scaffold for treating open bone defects, with potential for future clinical applications.

Keywords

Composite scaffold / Bone infection / Bone regeneration / Drug delivery / Psoralen