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Abstract: Graft remodeling following anterior cruciate ligament (ACL) reconstruction requires a long period of recovery before it is capable of withstanding physiological loads. Graft revascularization is extremely important in the remodeling process. In ACL reconstruction, the local administration of vascular endothelial growth factor (VEGF) significantly increased revascularization of the graft, but did not significantly affect the mechanical properties of the graft after implantation (Ju et al., 2006; Yoshikawa, et al., 2006). Our previous studies showed that transforming growth factor-β1 (TGFβ1) could promote improvements in mechanical strength in Achilles tendon regeneration, by regulating collagen type I and type III synthesis, cross-link formation, and matrix-remodeling (Hou et al., 2009). The current study aims to investigate whether the co-expression of TGFβ1/VEGF165 could beneficially affect the remodeling of ACL grafts. Bone marrow-derived mesenchymal stem cells (BMSCs), transfected with an adenoviral vector encoding TGFβ1, VEGF165 or TGFβ1/VEGF165, were surgically implanted into experimental ACL grafts, with non-transfected cells as a control. HE and toluidine blue staining, vascular number, and biomechanical features were analyzed at 3, 6, 12, and 24weeks after surgery. The results suggest that TGFβ1 expression, in the TGFβ1/VEGF165-transfected BMSCs, could accelerate the remodeling of the reconstructed ligament. The cross-talk between TGFβ1 and VEGF165 has positive consequences, as TGFβ1/VEGF165-transfected BMSCs significantly promoted angiogenesis of the reconstructed ligament at 3, 6, 12weeks, with the best mechanical properties being achieved at 24weeks. Furthermore, co-expression of these genes is more powerful and efficient than single gene therapy. [Copyright &y& Elsevier]

As more and more superbugs emerge, wounds are struggling to heal due to the inflammation that accompanies infection. Therefore, there is an urgent need to reduce the abuse of antibiotics and find nonantibiotic antimicrobial methods to counter infections to accelerate wound healing. In addition, common wound dressings struggle to cover irregular wounds, causing bacterial invasion or poor drug release, which reduces the wound healing rate. In this study, Chinese medicinal monomer paeoniflorin which can inhibit inflammation is loaded in mesoporous zinc oxide nanoparticles (mZnO), while Zn 2+ released from mZnO degradation can kill bacteria and facilitate wound healing. The drug-loaded mZnO was encapsulated by a hydrogel formed from oxidized konjac glucomannan and carboxymethyl chitosan via rapid Schiff base reaction to obtain an injectable drug-releasing hydrogel wound dressing. The immediate-formation hydrogel allows the dressing to cover any wound shape. In vitro and in vivo studies have demonstrated that the dressing has good biocompatibility and superior antibacterial properties, which can promote wound healing and tissue regeneration by promoting angiogenesis and collagen production, providing a promising perspective for the further development of multifunctional wound dressings.

Objective: To summarize the relationship between lateral femoral notch sign (LFNS) and anterior cruciate ligament (ACL) rupture., Methods: The relevant literature of LFNS at home and abroad in recent years was retrospectively reviewed, and its mechanism, diagnostic criteria and influencing factors in diagnosis of ACL rupture were summarized and analyzed., Results: The LFNS is associated with rotational stability of the knee. As an indirect sign of ACL rupture, the LFNS has high clinical diagnostic value, especially the diagnosis of ACL rupture with lateral meniscus injury., Conclusion: The diagnostic criteria and influencing factors of LFNS in diagnosis of ACL rupture are still unclear and controversial, which needs further study.

Objective: To evaluate the effects of age, gender, tibial anterior laxity and time from surgery to follow-up on patellofemoral articular cartilage status after anterior cruciate ligament reconstruction by second-look arthroscopy., Methods: A total of 102 patients undergoing arthroscopic anterior cruciate ligament reconstruction received second-look arthroscopy at least one year after operation. There were 71 males and 31 females with an average age of 27.1 (16-41) years. The average time from primary operation to second-look arthroscopy was 23 (12-51) months. Arthroscopic evaluations of patella and trochlea cartilage status for all patients were performed at initial anterior cruciate ligament reconstruction and second-look arthroscopy. The effects of age, gender, tibial anterior laxity and time from surgery to follow-up on patellofemoral articular cartilage status were retrospectively examined., Results: Patellofemoral articular cartilage degeneration continued to aggravate after anterior cruciate ligament reconstruction. There was no significant gender difference in patella and trochlear cartilage status. The patellar cartilage of patients under 30 years was worse than that of patients aged 30 years and above. Even though there was no significant difference. However, no significant inter-group difference existed in trochlear cartilage damage. With regard to KT-2000 side-to-side differences (0-3 mm vs >3 mm), no significant difference existed in patella and trochlear cartilage status. No significant difference was also found in the status of patella and trochlear cartilage between patients with body mass index under 24 kg/m(2) and patients 24 kg/m(2) and higher. The patellar cartilage of patients within 24 months after operation was significantly worse than that of patients 24 months and longer. However it did not apply to trochlear cartilage., Conclusion: The degeneration of patellofemoral articular cartilage worsens after anterior cruciate ligament reconstruction. And significantly more severe lesions are found in patellar cartilage of patients within 24 months after operation.

Repaired Achilles tendons typically take weeks before they are strong enough to handle physiological loads. Gene therapy is a promising treatment for Achilles tendon defects. The aim of the present study was to evaluate the histological/biomechanical effects of Transforming growth factor-beta1 (TGF-beta1) and vascular endothelial growth factor 165 (VEGF(165)) gene transfer on Achilles tendon healing in rabbits. Bone Marrow-Derived Mesenchymal Stem Cells (BMSCs) were transduced with adenovirus carrying human TGF-beta1 cDNA (Ad-TGF-beta1), human VEGF(165) cDNA (Ad-VEGF(165)), or both (PIRES-TGF-beta1/VEGF(165)) Viruses, no cDNA (Ad-GFP), and the BMSCs without gene transfer and the intact tendon were used as control. BMSCs were surgically implanted into the experimentally injured Achilles tendons. TGF-beta1 distribution, cellularity, nuclear aspect ratio, nuclear orientation angle, vascular number, collagen synthesis, and biomechanical features were measured at 1, 2, 4, and 8 weeks after surgery. The TGF-beta1 and TGF beta 1/VEGF(165) co-expression groups exhibited improved parameters compared with other groups, while the VEGF(165) expression group had a negative impact. In the co-expression group, the angiogenesis effects of VEGF(165) were diminished by TGF-beta1, while the collagen synthesis effects of TGF-beta1 were unaltered by VEGF(165). Thus treatment with TGF-beta1 cDNA-transduced BMSCs grafts is a promising therapy for acceleration and improvement of tendon healing, leading to quicker recovery and improved biomechanical properties of Achilles tendons.

Collagen content and cross-linking are believed to be major determinants of tendon structural integrity and function. The current study aimed to investigate the effects of transforming growth factor (TGF)-beta1 on the collagen content and cross-linking of Achilles tendons, and on the histological and biomechanical changes occurring during Achilles tendon healing in rabbits. Bone marrow-derived mesenchymal stem cells (BMSCs) transfected with the TGF-beta1 gene were surgically implanted into experimentally injured Achilles tendons. Collagen proteins were identified by immunohistochemical staining and fiber bundle accumulation was revealed by Sirius red staining. Achilles tendons treated with TGF-beta1-transfected BMSCs showed higher concentrations of collagen I protein, more rapid matrix remodeling, and larger fiber bundles. Thus TGF-beta1 can promote mechanical strength in healing Achilles tendons by regulating collagen synthesis, cross-link formation, and matrix remodeling.