Application of Porous Polyetheretherketone Scaffold/Vancomycin-Loaded Thermosensitive Hydrogel Composites for Antibacterial Therapy in Bone Repair.

Polyetheretherketone (PEEK) has been widely used in bone repair, but it often fails due to bacterial infection. Herein, a high-strength porous polyetheretherketone scaffold (ps-PK) loaded with antibacterial drug-loaded hydrogel strategy is proposed. The prepared ps-PK possesses high porosity (30.8-64.7%) and the compression modulus is between 0.4 and 0.98 GPa. The interconnected pore-type structure endows it with a drug loading capacity. Poly(D,L -lactic acid-co-glycolic acid)-b-Poly(ethylene glycol)-b-Poly(D,L -lactic acid-co-glycolic acid) (PLGA-PEG-PLGA) thermoresponsive hydrogels loaded with vancomycin are used as the drug sustained-release system. The vancomycin-loaded hydrogels in the solution state at a low temperature are filled into a porous polyetheretherketone scaffold (ps-PK-VGel) and formed a gel state after implantation in vivo. The antibacterial rate of ps-PK-VGel against methicillin-resistant staphylococcus aureus in vitro is 99.7% and histological observation in vivo demonstrates that the ps-PK-VGel shows obvious antibacterial activity. Given its excellent antibacterial ability and mechanical properties, the porous PEEK scaffold composite drug-loaded thermosensitive hydrogel has great potential in bone repair surgery applications.

Dextran sulfate-triamcinolone acetonide conjugate nanoparticles for targeted treatment of osteoarthritis.

Osteoarthritis (OA) is a synovial inflammatory condition characterized by cartilage destruction and osteophyte formation. Macrophages play a central role in OA pathogenesis by producing proinflammatory cytokines. Intra-articular corticosteroid administration can relieve refractory pain and inflamed effusion of knee joints. However, limitations, such as rapid clearance from the joint space, potential damage to articular cartilage, and accelerated joint degeneration, may hamper the clinical application of corticosteroids. In this study, we reported the design and preparation of dextran sulfate-triamcinolone acetonide conjugate (DS-TA) nanoparticles (NPs) for treating OA by specifically targeting scavenger receptor class A (SR-A) on activated macrophages. We verified the excellent targeting specificity of DS-TA NPs to SR-A by flow cytometry and confocal laser scanning microscopy. DS-TA NPs were found to effectively reduce the viability of activated macrophages (RAW 264.7 cells) and the expression of proinflammatory cytokines. Intra-articular injection of DS-TA NPs effectively alleviated the structural damages to the joint cartilage, as confirmed in histopathological analysis. Additionally, DS-TA NPs decreased the expression of proinflammatory cytokines, including IL-1ß, IL-6, and TNF-α, in the cartilage tissue. Thus, DS-TA NPs are a potential therapeutic nanomedicine for the targeted treatment of OA.

[Expanded curettage and bone cement filling combined with internal fixation for the treatment of Campanacci III giant cell tumour of knee joint].

OBJECTIVE: To evaluate clinical effects of expanded curettage and bone cement filling combined with internal fixation in treating Campanacci III giant cell tumor of knee joint. METHODS: From January 2006 to December 2016, 21 patients with Campanacci III giant cell tumor of knee joint were treated by expanded curettage and bone cement filling combined with internal fixation, including 11 males and 10 females with an average age of(35.24±10.56) years old (ranged from 21 to 61 years old). The courses of disease ranged from 1.5 to 24.0 months with an average of(8.1±4.4) months. Among them, 8 patients were distal femur and 13 patients were proximal tibia. All patients were primary tumors. Musculoskeletal Tumor Society(MSTS) scores were used to evaluate lower limb function before and after operation. X-ray was used to observe healing of lesions and the occurrence of adverse reactions. RESULTS: All incisions were healed at grade A without complications such as infection and internal fixation failure. All patients were followed up from 8 to 56 months with an average of (29.62±9.48) months. MSTS score at the latest follow-up 26.71±2.35 was higher than that of before operation 15.24±1.14, and had statistical significance(t=20.160, P=0.000). The results of X-ray at final following-up showed internal fixation was well, and no loosening and fracture of subchondral bone. Three patients recurred giant cell tumor and replaced with tumor prosthesis. CONCLUSIONS: Expanded curettage and bone cement filling with internal fixation for the treatment of Campanacci III giant cell tumor of knee joint could effectively retain limb function and reduce tumor recurrence rate.