Xinting Cheng,Zhou Zhu,Yanhua Liu,Yiyuan Xue,Xiaomeng Gao,Jian Wang,Xibo Pei,Qianbing Wan
Bisphosphonates (BPs) are routinely administered for the treatment of turnover bone diseases. To avoid the undesirable adverse effects of long-term usage of bisphosphonates and improve their bioavailability in the bone microenvironment, we initially encapsulated risedronate (RIS) molecules inside nanoscale zeolitic imidazolate framework-8 particles (nZIF-8) by a one-step synthesis method to generate RIS@ZIF-8 nanoparticles. RIS@ZIF-8 nanoparticles displayed high loading encapsulation efficiency (64.21 ± 2.48%), good biocompatibility, controlled drug release capacity, and dual effects for bone regeneration. This work explored the potential of RIS@ZIF-8 nanoparticles, which could not only enhance ATP production, induce extracellular matrix (ECM) mineralization, and upregulate the expression levels of osteogenic genes but also effectively inhibit the formation of multinucleated giant osteocasts and decrease the Rankl/Opg ratio. Overall, RIS@ZIF-8 nanoparticles could be a very promising approach to synergistically enhance osteogenic and antiresorptive properties for bone regeneration, which could be utilized for the local treatment of bone defects.
This study introduces a novel 3D scaffold for bone regeneration, composed of silk fibroin, chitosan, nano-hydroxyapatite, LL-37 antimicrobial peptide, and pamidronate. The scaffold addresses a critical need in bone tissue engineering by simultaneously combating bone infections and promoting bone growth. LL-37 was incorporated for its broad-spectrum antimicrobial properties, while pamidronate was included to inhibit bone resorption. The scaffold's porous structure, essential for cell infiltration and nutrient diffusion, was achieved through a freeze-drying process. In vitro assessments using SEM and FTIR confirmed the scaffold's morphology and chemical integrity. Antimicrobial efficacy was tested against pathogens of Staphylococcus aureus ( S. aureus ) and Pseudomonas aeruginosa ( P. aeruginosa ). In vivo studies in a murine model of infectious bone defect revealed the scaffold's effectiveness in reducing inflammation and bacterial load, and promoting bone regeneration. RNA sequencing of treated specimens provided insights into the molecular mechanisms underlying these observations, revealing significant gene expression changes related to bone healing and immune response modulation. The results indicate that the scaffold effectively inhibits bacterial growth and supports bone cell functions, making it a promising candidate for treating infectious bone defects. Future studies should focus on optimizing the release of therapeutic agents and evaluating the scaffold's clinical potential.