Xun Guo, Xiaoting Wang, Jianli Ren

2025, 6(1): 110–111. doi:https://doi.org/10.12336/biomatertransl.2025.01.010

Haoyang Du, Jiaxin Liu, Manjie Zhang

2025, 6(1): 106–109. doi:https://doi.org/10.12336/biomatertransl.2025.01.009

Junfeng Song, Tiancong Zhao

2025, 6(1): 103–105. doi:https://doi.org/10.12336/biomatertransl.2025.01.008

Wei Du, Jiang-Shan Gong, Xia Chen, Yang Wu, Yu Yang, Sheng Zhu, Yu Zhang, Bei Chen, Yi-Wei Liu, Ze-Hui He, Zhe Guan, Yan Zhang, Zhen-Xing Wang, Hui Xie

2025, 6(1): 85–102. doi:https://doi.org/10.12336/biomatertransl.2025.01.007

Orthopedic implant-associated infections pose a significant clinical challenge, often requiring surgical intervention along with systemic antibiotic treatments. To address this issue, we developed a novel approach using Ångstrom-scale silver particles (AgÅPs) with broad-spectrum antibacterial properties. Specifically, we formulated a polyethylene glycol hydrogel infused with AgÅPs (Gel-AgÅPs) designed for treating fracture fixation infections. This novel hydrogel formulation is injectable, ensuring precise adherence to both the exposed tissue and fracture surfaces, thereby allowing the direct targeted action of AgÅPs at the infection site. The Gel-AgÅPs significantly reduced the infection caused by Escherichia coli (a model pathogen of orthopedic implant infection) in a murine femoral fracture model. Moreover, the Gel-AgÅPs-treated infected fractures healed completely within 6 weeks, exhibiting bone formation and mechanical strength comparable to those of uninfected fractures. Further analysis revealed a significant downregulation of local inflammatory response as evidenced by a lower expression of inflammatory markers in Gel-AgÅPs-treated fractures compared to untreated infected controls. Furthermore, Gel-AgÅPs exhibited a unique ability to inhibit osteoclast differentiation, a critical factor in infection-induced bone degradation, without impacting osteoblast activity. In conclusion, Gel-AgÅPs exerted a dual therapeutic effect by eradicating bacterial infection and mitigating inflammation-induced osteoclast activity, thereby expediting infected fracture healing. This innovative approach is a promising therapeutic alternative to conventional antibiotic treatments, potentially transforming the treatment landscape for orthopedic implant-associated infections.

Ning Jiang, Mingyan Jiang, Jianshu Chen, Ali Mohsin, Yuqing Mu, Xiaoping Yi, Yingping Zhuang, Jiangchao Qian, Jiaofang Huang

2025, 6(1): 73–84. doi:https://doi.org/10.12336/biomatertransl.2025.01.006

Photothermal therapy is a safe and effective tumour treatment strategy due to its excellent spatiotemporal controllability. However, interferon gamma in the tumour microenvironment is upregulated after photothermal therapy, which enhances the expression of programmed cell death ligand 1 (PD-L1) in tumour cells. This further promotes immunosuppression and tumour metastasis, resulting in a poor prognosis in cancer therapy. Traditional nanodrugs often face challenges in penetrating the dense extracellular matrix of solid tumours, whereas certain probiotics possess the ability to specifically colonise the core regions of tumours. In this research, we used Escherichia coli Nissle 1917 (ECN) as a chassis cell and self-assembly polydopamine (PDA) on the ECN surface. The black PDA@ECN (notes as PE) actively colonises at the tumour site and produces a photothermal effect under 808 nm laser irradiation to kill tumour cells. To overcome the high expression of PD-L1 induced after photothermal therapy, metformin (MET) was also encapsulated in PE to form PDA@MET@ECN (notes as PME). In vivo experiments demonstrated that PME effectively inhibited the PD-L1 expression and growth of CT26 tumour cells. Overall, PME reverses the immunosuppressive tumour microenvironment and enhances the effect of photothermal/immune therapy in tumour treatment.