Self-Tandem Bio-Heterojunctions Empower Orthopedic Implants with Amplified Chemo-Photodynamic Anti-Pathogenic Therapy and Boosted Diabetic Osseointegration

Abstract

<p>Hyperglycemic microenvironment in diabetes mellitus inevitably stalls the normal orchestrated course of bone regeneration and encourages pathogenic multiplication. Photodynamic therapy (PDT) and chemo-dynamic therapy (CDT) are extensively harnessed to combat pathogens, yet deep-seated diabetic bone defect has difficulty in supplying sufficient oxygen (O₂) and hydrogen peroxide (H₂O₂) stocks, resulting in inferior therapeutic efficiency. To address the tough plaguing, the self-tandem bio-heterojunctions (bio-HJs) consisting of molybdenum disulfide (MoS₂), graphene oxide (GO), and glucose oxidase (GOx) are constructed on orthopedic polyetheretherketone (PEEK) implants (SP-Mo/G@GOx) for amplified chemo-photodynamic anti-pathogenic therapy and boosted osseointegration in the deep-seated diabetic micromilieu. In this system, GOx exhausts glucose to generate H₂O₂, which provides an abundant stock for CDT. Besides, the bio-HJs produce hyperthermia upon near-infrared light (NIR) to accelerate the dynamic process, which amplifies the antibacterial potency of PDT by promoting the vast yield of singlet oxygen (¹O₂) in a self-tandem manner. More importantly, in vivo and in vitro assays demonstrate that the engineered implants exert a captivated bactericidal ability and significantly boost osseointegration in an infectious diabetic bone defect model. As envisaged, this study furnishes a novel tactic to arm orthopedic implants with self-tandem capability for the remedy of infectious diabetic bone defects.</p>