Due to its excellent biological and mechanical properties, silk fibroin has been intensively explored for tissue engineering and regenerative medicine applications. However, lack of translational evidence has hampered its clinical application for tissue repair. Here a silk fibroin film is developed and its translational potential is investigated for skin repair by performing comprehensive preclinical and clinical studies to fully evaluate its safety and effectiveness. The silk fibroin film fabricated using all green chemistry approaches demonstrates remarkable characteristics, including transmittance, fluid handling capacity, moisture vapor permeability, waterproofness, bacterial barrier properties, and biocompatibility. In vivo rabbit full-thickness skin defect study shows that the silk fibroin film effectively reduces the average wound healing time with better skin regeneration compared with the commercial wound dressings. Subsequent assessment in porcine model confirms its long-term safety and effectiveness for full-thickness skin defects. Finally, a randomized single-blind parallel controlled clinical trial with 71 patients shows that the silk fibroin film significantly reduces the time to wound healing and incidence of adverse events compared to commercial dressing. Therefore, the study provides systematic preclinical and clinical evidence that the silk fibroin film promotes wound healing thereby establishing a foundation towards its application for skin repair and regeneration in the clinic.
PRP is widely used in the clinical management of chronic tendinopathy. However, the clinical results are ambiguous. It is imperative to understand the influence of leukocytes on PRP-mediated tissue healing in vivo, which could facilitate the better clinical management of chronic tendinopathy. Further studies are needed to translate our findings to the clinical setting.
a b s t r a c tRotator cuff tear is one of the most common types of shoulder injuries, often resulting in pain and physical debilitation. Allogeneic tendon-derived decellularized matrices do not have appropriate pore size and porosity to facilitate cell infiltration, while commercially-available synthetic scaffolds are often inadequate at inducing tenogenic differentiation. The aim of this study is to develop an advanced 3D aligned collagen/silk scaffold (ACS) and investigate its efficacy in a rabbit massive rotator cuff tear model. ACS has similar 3D alignment of collagen fibers as natural tendon with superior mechanical characteristics. Based on ectopic transplantation studies, the optimal collagen concentration (10 mg/ml), pore diameter (108.43 ± 7.25 lm) and porosity (97.94 ± 0.08%) required for sustaining a stable macro-structure conducive for cellular infiltration was determined. Within in vitro culture, tendon stem/progenitor cells (TSPCs) displayed spindle-shaped morphology, and were well-aligned on ACS as early as 24 h. TSPCs formed intercellular contacts and deposited extracellular matrix after 7 days. With the in vivo rotator cuff repair model, the regenerative tendon of the ACS group displayed more conspicuous native microstructures with larger diameter collagen fibrils (48.72 ± 3.75 vs. 44.26 ± 5.03 nm) that had better alignment and mechanical properties (139.85 ± 49.36 vs. 99.09 ± 33.98 N) at 12 weeks post-implantation. In conclusion, these findings demonstrate the positive efficacy of the macroporous 3D aligned scaffold in facilitating rotator cuff tendon regeneration, and its practical applications for rotator cuff tendon tissue engineering.
Statement of SignificanceMassive rotator cuff tear is one of the most common shoulder injuries, and poses a formidable clinical challenge to the orthopedic surgeon. Tissue engineering of tendon can potentially overcome the problem. However, more efficacious scaffolds with good biocompatibility, appropriate pore size, favorable inductivity and sufficient mechanical strength for repairing massive rotator cuff tendon injuries need to be developed. In this study, we developed a novel macroporous 3D aligned collagen/silk scaffold, and demonstrated that this novel scaffold enhanced the efficacy of rotator cuff tendon regeneration by inducing aligned supracellular structures similar to natural tendon, which in turn enhanced http://dx
IntroductionOsteoarthritis (OA) is the most prevalent joint disorder in the elderly population, and inflammatory mediators like IL-1β were thought to play central roles in its development. Schisandrin B, the main active component derived from Schisandra chinensis, exhibited anti-oxidative and antiinflammatory properties.MethodsIn the present study, the protective effect and the underlying mechanism of Schisan-drin B on OA was investigated in vivo and in vitro.ResultsThe results showed that Schisandrin B decreased IL-1β-induced upregulation of matrix metalloproteinase 3 (MMP3), MMP13, IL-6, and inducible nitric oxide synthase (iNOS) and increased IL-1β-induced downregulation of collagen II, aggrecan, and sox9 as well. Schisandrin B significantly decreased IL-1β-induced p65 phosphorylation and nuclear translocation of p65 in rat chondrocytes. Mitogen-activated protein kinase (MAPK) activation was also inhibited by Schisandrin B, as evidenced by the reduction of p38, extracellular signal-regulated kinase (Erk), and c-Jun amino-terminal kinase (Jnk) phosphorylation. In addition, Schisandrin B prevented cartilage degeneration in rat OA model with significantly lower Mankin’s score than the control group.ConclusionOur study demonstrated that Schisandrin B ameliorated chondrocytes inflammation and OA via suppression of nuclear factor-κB (NF-κB) and MAPK signal pathways, indicating a therapeutic potential in OA treatment.
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