Yue Song
The Fourth Medical Center, Chinese PLA General Hospital, Beijing 100036, China.
*Corresponding author: Yue Song
Abstract
Infected bone defects pose significant clinical challenges due to impaired osteogenesis and persistent bacterial infections, with conventional therapies often proving inadequate. To address this, we developed a multifunctional scaffold integrating photothermal nanoparticles (PTNPs) and antimicrobial peptide LL-37 for synergistic antibacterial and osteogenic effects. The study synthesized phthalocyanine-phenylalanine dipeptide-LL-37 (Pc-FF-LL37) nanoparticles through molecular self-assembly, exhibiting a 56.9 nm hydrodynamic diameter and 43.6% photothermal conversion efficiency (PTCE) under 680 nm irradiation, as confirmed by dynamic light scattering and UV-vis spectroscopy. Three-dimensional (3D) printed scaffolds combining Pc-FF-LL37 with nano-hydroxyapatite/collagen (nHA/Col) demonstrated concentration-dependent antibacterial activity, with 5% Pc-FF-LL37 scaffolds achieving complete MRSA eradication (p<0.05) in colony counting assays. In vitro, these scaffolds enhanced bone marrow stromal cell (BMSC) osteogenesis, showing elevated alkaline phosphatase (ALP) activity (2.1-fold increase), mineralization (Alizarin Red staining), and upregulated osteogenic genes (Bmp-2, Runx-2, Alp, Col1a1) versus controls (p<0.05). Micro-CT analysis of rat femoral condyle defect models revealed superior bone regeneration with 5% Pc-FF-LL37 scaffolds, exhibiting 38% greater bone volume fraction (BV/TV) and improved trabecular parameters (Tb.Th, Tb.N) compared to nHA/Col alone (p<0.05), while Gram staining confirmed infection clearance. This dual-functional scaffold combines photothermal therapy (PTT)-mediated antibacterial action with pro-osteogenic capacity, offering a promising solution for infected bone defects. Future studies should focus on large-animal validation and clinical translation of this integrated therapeutic approach.
References
[1] Zheng B, Ye J, Huang Y, Xiao M. Phthalocyanine-based photoacoustic contrast agents for imaging and theranostics. Biomater Sci. 2021;9(23):7811-25.
[2] Li S, Zhao L, Chang R, Xing R, Yan X. Spatiotemporally coupled photoactivity of phthalocyanine-peptide conjugate self-assemblies for adaptive tumor theranostics. Chemistry. 2019;25(58):13429-35.
[3] Nagaoka I, Tamura H, Reich J. Therapeutic potential of cathelicidin peptide LL-37, an antimicrobial agent, in a murine sepsis model. Int J Mol Sci. 2020;21(17):5973.
[4] Song Y, Wu H, Gao Y, et al. Zinc silicate/nano-hydroxyapatite/collagen scaffolds promote angiogenesis and bone regeneration via the p38 MAPK pathway in activated monocytes. ACS Appl Mater Interfaces. 2020;12(14):16058-75.
[5] Wang M, Yang Y, Chi G, et al. A 3D printed Ga containing scaffold with both anti-infection and bone homeostasis-regulating properties for the treatment of infected bone defects. J Mater Chem B. 2021;9(23):4735-45.
[6] Wang Y, Zhang H, Qiang H, et al. Innovative biomaterials for bone tumor treatment and regeneration: tackling postoperative challenges and charting the path forward. Advanced Healthcare Materials. 2024;13(16):2304060.
[7] Sun J, Xing F, Braun J, et al. Progress of phototherapy applications in the treatment of bone cancer. International Journal of Molecular Sciences. 2021;22(21):11354.
[8] Wang S, Wang F, Zhao X, et al. The effect of near-infrared light-assisted photothermal therapy combined with polymer materials on promoting bone regeneration: A systematic review. Materials & Design. 2022;217:110621.
How to cite this paper
Multifunctional Photothermal Nanoparticle-infused Scaffold for Synergistic Antibacterial and Osteogenic Therapy in Infected Bone Defects
How to cite this paper: Yue Song. (2025) Multifunctional Photothermal Nanoparticle-infused Scaffold for Synergistic Antibacterial and Osteogenic Therapy in Infected Bone Defects. International Journal of Clinical and Experimental Medicine Research, 9(3), 314-319.
DOI: http://dx.doi.org/10.26855/ijcemr.2025.05.011