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Polyether ether ketone (PEEK) is gaining recognition as a highly promising polymer for orthopedic implants, attributed to its exceptional biocompatibility, ease of processing, and radiation resistance. However, its long‐term in vivo application faces challenges, primarily due to suboptimal osseointegration from postimplantation inflammation and immune reactions. Consequently, biofunctionalization of PEEK implant surfaces emerges as a strategic approach to enhance osseointegration and increase the overall success rates of these implants. In our research, we engineered a multifaceted PEEK implant through the in situ integration of chitosan‐coated zinc‐doped bioactive glass nanoparticles (Zn‐BGNs). This novel fabrication imbues the implant with immunomodulatory capabilities while bolstering its osseointegration potential. The biofunctionalized PEEK composite elicited several advantageous responses; it facilitated M2 macrophage polarization, curtailed the production of inflammatory mediators, and augmented the osteogenic differentiation of bone marrow mesenchymal stem cells. The experimental findings underscore the vital and intricate role of biofunctionalized PEEK implants in preserving normal bone immunity and metabolism. This study posits that utilizing chitosan‐BGNs represents a direct and effective method for creating multifunctional implants. These implants are designed to facilitate biomineralization and immunomodulation, making them especially apt for orthopedic applications. [ABSTRACT FROM AUTHOR]

Postoperative implant infection is a severe complication in orthopedic surgery, often leading to implant failure. Current treatment strategies mainly rely on systemic antibiotic therapies, despite contributing to increasing bacterial resistance. In recent years, nanomaterials have gained attention for their potential in anti-infection methods. They exhibit more substantial bactericidal effects and lower drug resistance than conventional antimicrobial agents. Nanomaterials also possess multiple bactericidal mechanisms, such as physico-mechanical interactions. Additionally, they can serve as carriers for localized antimicrobial delivery. This review explores recent applications of nanomaterials with different morphologies in post-orthopedic surgery infections and categorizes their bactericidal mechanisms. [ABSTRACT FROM AUTHOR]

Postmenopausal osteoporosis, a metabolic bone disease associated with aging that affects bones throughout the body, is emerging as an urgent public health concern and imposes a substantial healthcare burden on society. The clinical application of bisphosphonate, the primary treatment for osteoporosis, is limited owing to the drug's severe complications. Herein, we investigate the synthesis and utilization of strontium-doped mesoporous bioactive glass loaded with alendronate (ALN@Sr-MBG) as a novel therapeutic agent for osteoporosis, to explore its potential as an alternative to alendronate (ALN). Strontium-doped mesoporous bioactive glass (Sr-MBG) was synthesized using the sol–gel method, while ALN@Sr-MBG was obtained via incorporating Sr-MBG into an alendronate saturated solution. The bioactivities of ALN@Sr-MBG, including biotoxicity, inflammation inhibition, and anti-osteoclast differentiation, were investigated in vitro using CCK-8, flow cytometry, tartrate-resistant acid phosphatase (TRAP) staining, and RT-PCR assays. Animal models were established by surgically removing the ovaries from non-pregnant female C57/BL mice, followed by weekly intraperitoneal injections of ALN@Sr-MBG, ALN, or excipients. After 8 weeks, the mice femurs were extracted and analyzed through micro-CT scanning and hematoxylin-eosi, osteoblastic, and osteogenic staining. These in vitro findings demonstrate that ALN@Sr-MBG displays enhanced biological efficacy compared to ALN in terms of inflammation inhibition, osteogenesis promotion, and osteoclastogenesis inhibition. Furthermore, micro-CT analysis revealed that ALN@Sr-MBG significantly augments bone mineral density (BMD), bone volume fraction (BV/TV), trabecular number (Tb.N), and trabecular thickness (Tb.Th), while reducing trabecular separation (Tb.Sp) and the structural model index (SMI) in mice with ovariectomy-induced osteoporosis. The osteoblast and osteogenic staining results indicate the enhanced bioactivities of ALN@Sr-MBG in promoting bone formation and inhibiting bone resorption compared to ALN. In vitro and in vivo assessments further confirmed that ALN@Sr-MBG exhibits superior anti-osteoporotic bioactivity compared to ALN. This study's findings confirm the potential of ALN@Sr-MBG as a novel alternative therapy to ALN and a drug candidate for the treatment of osteoporosis. [ABSTRACT FROM AUTHOR]

This paper studies the output containment control problem for heterogeneous multi-agent systems subject to unknown time-varying disturbances by designing fully distributed anti-disturbance control protocols. Fully distributed observers are designed to estimate convex combination of leader states, which are independent of any global information including global leaders' dynamics and global graph. There are external disturbances to contaminate the control inputs of the followers, which may damage the cooperation of the systems. Then adaptive anti-disturbance compensators are designed to eliminate the adverse effects of the external disturbances. Based on the proposed fully distributed observers and adaptive anti-disturbance compensators, adaptive anti-disturbance containment control protocols are provided to ensure that the output trajectories of each follower can converge to the dynamic convex hull spanned by the leader outputs. Finally, a numerical example and a practical example of heterogeneous mobile vehicles are given to demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Due to its excellent mechanical and low‐friction properties, polyetheretherketone (PEEK) has been widely investigated for use in orthopedic applications over the past decade. However, the bioinertness and poor osteogenic properties of PEEK have hampered its clinical application. In this study, the surface of PEEK was modified by co‐treatment with hydrofluoric acid and nitric acid (AFN). The microstructures of the modified PEEK surfaces were investigated using scanning electron microscopy. The water contact angles of the surfaces were also measured. To evaluate their cytocompatibility, PEEK samples were used as substrates to culture rat bone mesenchymal stem cells, and cell adhesion, viability, and expression of specific marker genes were measured. Treatment of PEEK with AFN (PEEK‐AFN) was found to enable better osteoblast adhesion, spreading, and proliferation; the activity of alkaline phosphatase (an early osteogenic differentiation marker) was also found to be enhanced post‐treatment. Furthermore, PEEK‐AFN was able to modulate macrophage polarization and down regulated the expression of proinflammatory factors via inhibiting the NF‐κB pathway. Thus, treatment of PEEK with AFN could promote M2 polarization of the macrophages and stimulate the differentiation of osteoblasts. These results provide valuable information that could facilitate the use of PEEK‐based composites as bone implant materials. [ABSTRACT FROM AUTHOR]

This paper gives full consideration to the hidden Markov model‐based ℋ∞ control problem for nonlinear Markov jump systems under multichannel random attacks via Takagi–Sugeno fuzzy model. The system state is transmitted to controller through the multiple channels in which each channel obtains transmission permission based on a dispatcher and suffers from random attacks described by the Bernoulli variables. The hidden Markov model is utilized to describe the asynchronous mode phenomenon between controller and system. By choosing a compatible Lyapunov function, some sufficient conditions are developed to achieve stochastic stability of the closed‐loop system with a prescribed ℋ∞ performance. In the end, two examples are provided to illuminate the correctness of the devised technique. [ABSTRACT FROM AUTHOR]