Intra-articular delivery of flurbiprofen sustained release thermogel: improved therapeutic outcome of collagenase II-induced rat knee osteoarthritis.

Knee osteoarthritis (OA) is a common degenerative disease. Intra-articular administration of flurbiprofen is frequently employed in clinic to treat OA, while repeated injections are required because of the limited effective duration. To improve therapeutic outcome and prolong the treatment interval, a poly(ε-caprolactone-co-lactide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-lactide) (PCLA-PEG-PCLA) triblock copolymer based flurbiprofen thermosensitive gel for the sustained intra-articular drug delivery was designed in this study. The anti-OA effects of this flurbiprofen thermogel were investigated on collagenase II-induced rat knee OA model by multiple approaches and compared with that of conventional sodium hyaluronate and flurbiprofen injecta. In vitro drug release studies indicated that flurbiprofen was sustained released from the thermosensitive gel for more than three weeks. This sustained drug release system exerted comparable short-term analgesic effects and distinctly improved long-term analgesic efficacy in terms of the increased percentage of the total ipsilateral paw print intensity and the reduced Knee-Bend scores of OA rats. The inflammatory response was attenuated in the samples of flurbiprofen gel treated group by showing decreased IL-1, IL-6, and IL-11 levels in the joint fluid and down-regulated IL-1, IL-6, IL-11, COX-2, TNF-α, and NF-κB/p65 expression in the articular cartilages. The results suggest the suitability of thermosensitive copolymer PCLA-PEG-PCLA for sustained intra-articular effects of flurbiprofen and provide in vivo experimental evidence for potential clinical application of this flurbiprofen delivery system to better management of OA cases.

Sinomenine Attenuates Cartilage Degeneration by Regulating miR-223-3p/NLRP3 Inflammasome Signaling.

Sinomenine (SIN) has been shown to protect against IL-1ß-induced chondrocyte apoptosis in vitro. However, the role of SIN in the anterior cruciate ligament transection (ACLT)-induced osteoarthritis (OA) mouse model and its underlying molecular mechanisms remain unclear. In the present study, the protective effect of SIN on ACLT-induced articular cartilage degeneration and IL-1ß-induced chondrocyte apoptosis miR-223-3p/NLRP3 signaling regulation was investigated. Safranin O staining was performed to evaluate the pathological changes of articular cartilage. Chondrocyte apoptosis was measured with Annexin V-fluorescein isothiocyanate/polyimide (annexin V-FITC/PI) staining using flow cytometry. Gene and protein expression were detected by RT-qPCR and Western blotting, respectively. SIN administration markedly improved articular cartilage degradation in mice undergoing ACLT surgery. In addition, SIN treatment downregulated the levels of inflammatory cytokines and the protein expression of NLRP3 inflammasome components and upregulated the expression of miR-223-3p in OA mice and IL-1ß-stimulated chondrocytes. In vitro, we found that NLRP3 was a direct target of miR-223-3p, and overexpression of miR-223-3p blocked IL-1ß-induced apoptosis and the inflammatory response in chondrocytes. These findings indicate that miR-223-3p/NLRP3 signaling could be used as a potential target of SIN for the treatment of OA.

Upregulation of BAG3 with apoptotic and autophagic activities in maggot extract­promoted rat skin wound healing.

Maggot extract (ME) accelerates rat skin wound healing, however its effect on cell maintenance in wound tissues remains unclear. B­cell lymphoma (Bcl) 2­associated athanogene (BAG)3 inhibits apoptosis and promotes autophagy by associating with Bcl­2 or Beclin 1. Bcl­2, the downstream effector of signal transducer and activator of transcription 3 signaling, is enhanced in ME­treated wound tissues, which may reinforce the Bcl­2 anti­apoptotic activity and/or cooperate with Beclin 1 to regulate autophagy during wound healing. The present study investigated expression levels of BAG3, Bcl­2, Beclin 1 and light chain (LC)3 levels in rat skin wound tissues in the presence and absence of ME treatment. The results revealed frequent TUNEL­negative cell death in the wound tissues in the early three days following injury, irrespective to ME treatment. TUNEL­positive cells appeared in the wound tissues following 4 days of injury and 150 µg/ml ME efficiently reduced apoptotic rate and enhanced BAG3 and Bcl­2 expression. Elevated Beclin 1 and LC3 levels and an increased LC3 II ratio were revealed in the ME­treated tissues during the wound healing. The results of the present study demonstrate the anti­apoptotic effects of BAG3 and Bcl­2 in ME­promoted wound healing. Beclin 1/LC3 mediated autophagy may be favorable in maintaining cell survival in the damaged tissues and ME­upregulated BAG3 may enhance its activity.

Applying Electrospun Gelatin/Poly(lactic acid-co-glycolic acid) Bilayered Nanofibers to Fabrication of Meniscal Tissue Engineering Scaffold.

The menisci are fibrocartilaginous tissues composed primarily of an interlacing network of collagen fibers with nanoscale diameter. Electrospinning is a suitable process of producing nanoscale fibers that mimic collagen fibers. In this study, a bilayered scaffold (group B), which consists of a gelatin nanofiber mesh and a PLGA nanofiber mesh, has been fabricated through an electrospinning method. At the same time, we electrospun pure PLGA fibrous mesh (group A) and gelatin/PLGA composite fibrous mesh (group C) as control groups. In order to compare all scaffold morphologies, the scaffolds were imaged by SEM and some parameters were measured and analyzed as following: Diameters of fibrils are from the smallest of less than average 0.14 µm for group C to the biggest of nearly average 0.38 µm for group B. The scaffolds pore diameters are from average 4.9 µm for group A to average 11.2 µm for group B. Porosity rates show that the group B has the highest porosity rate at about 91%. The scaffolds' properties were compared and analyzed, including hydrophilicity property (water contact angle) and mechanical properties (tensile strength). The results of water contact angle showed the group B is the most hydrophil among the groups. The results of tensile strength showed the tensile strength of group C is the weakest among the groups. All the results showed significant differences between the groups. Finally, in vitro, the meniscal cells derived from New Zealand white rabbits menisci were seeded in the scaffolds. We observed the cells proliferation behavior in the scaffolds. All above demonstrates that a bi-layered gelatin/PLGA scaffold reveals not only concurrent effects of mechanics and cytocompatibility in a fibrous context, but also a promising scaffold for future meniscal repair strategies.