Aimin Wang

A new TGF-β3 controlled-released chitosan scaffold for tissue engineering synovial sheath

The post-operative outcome of flexor tendon healing remains limited by flexor tendon adhesion that reduces joint range of motion. Despite improvement in different methods, peritendinous adhesion formation continues to present a formidable challenge. Recent studies showed that transforming growth factor-β3 (TGF-β3) may be the key factor to reducing adhesion formation in skin or tendon. In this study, we designed a novel type of tissue engineering synovial sheath containing TGF-β3, to prevent flexor tendon adhesion. First, to achieve a stable release of TGF-β3, chitosan microspheres, prepared by crosslinking-emulsion, were used for the delivery of TGF-β3. Second, a three-dimensional chitosan scaffold was prepared by lyophilization, and TGF-β3 microspheres were carefully introduced into the scaffold. Then, synovial cells were cultured and then seeded into the TGF-β3 loaded scaffold to produce TGF-β3 controlled-released tissue engineering synovial sheath. Tests clearly demonstrated that the scaffold has good structure and compatibility with cells. These results expand the feasibility of combinative strategies of controlled protein release and tissue-engineered synovial sheath formation. Application of this scaffold to tendon repair sites may help to prevent adhesion of tendon healing.

Effect of transforming growth factor-β3 on the expression of Smad3 and Smad7 in tenocytes

Tendon adhesion is a common problem in the healing of injured tendons. The molecular mechanisms of the TGF-β/Smad signaling pathway have been determined, and the role of TGF-β has been well characterized in wound healing. However, the intracellular mechanism or downstream signals by which TGF-β3 modulates its effects on tendon healing have not been well elucidated. The aim of this study was to determine the effect of TGF‑β3 on the TGF-β/Smad signaling pathway in tenocytes. Quantitative polymerase chain reaction and western blot analysis were used to analyze the effect of TGF‑β3 on the regulation of the expression of Smad proteins in tenocytes. The results demonstrated that TGF‑β3 has no significant effect on the proliferation of tendon cells. The addition of TGF‑β3 to tenocytes can significantly downregulate the expression of Smad3 and upregulate the expression of Smad7 at the gene and protein levels. The results demonstrate that TGF‑β3 may regulate Smad3 and Smad7 proteins through the TGF-β/Smad signaling pathway to minimize extrinsic scarring. Thus, it may provide a novel approach to decrease tendon adhesion and promote tendon healing.

Damage Control Orthopedics Management as Vital Procedure in Elderly Patients with Femoral Neck Fractures Complicated with Chronic Renal Failure: A Retrospective Cohort Study.

Background Chronic renal failure (CRF) predisposes to hip fractures in elderly patients, with high subsequent mortality. Selection and timing of the surgical procedure of such patients is a serious challenge. Many clinicians believe in earlier surgery as preferable and providing better outcomes. Damage control orthopedics (DCO) aids to adjust and optimize the overall condition of patients. Methods In 32 patients with femoral neck fractures complicated with CRF, we evaluated how the timing of the surgery determines the mortality rates if the DCO approach is applied. Preoperative ASA grading, POSSUM score, P-POSSUM score and DCO were carried out. Based on the assessment, timing of the surgery was ascertained. Results Of a total of 32 patients, twenty-nine patients were accepted for either early (< 48 hours; n = 18) or delayed (3–10 days; n = 10) surgery. Hip arthroplasty (total hip arthroplasty and hemiarthroplasty) was the principal surgery option. All patients survived operation and were followed up postoperatively with the average time of 30 days. Postoperative complications tended to occur at higher rates in the early vs. delayed surgery group (7/18 vs. 5/10). During follow up, a total of 3 patients died in both groups (2/18 in the early surgery and 1/10 in the delayed surgery group), mostly from multi-organ failures and acute respiratory distress syndrome. There was no significant difference in complication rates and Harris hip score between both groups. Conclusion In patients with femoral neck fracture complicated with CRF, delaying the surgery for several days does not increase the incidence of postoperative adverse events.

Anti-thrombosis effect of LRRFIP1 shRNA lentivirus in a mouse model of deep vein thrombosis.

INTRODUCTION Deep vein thrombosis (DVT) is one of the common complications of orthopedic surgery. Low molecular weight heparin (LMWH) is a usually used agent for DVT, but it would increase the risk of bleeding. LRRFIP1 has been shown to play an important role in the formation of thrombosis. Therefore, we investigated the effect of LRRFIP1 shRNA lentivirus on DVT in mice. MATERIALS AND METHODS Lentiviral Vectors carrying LRRFIP1 shRNA were constructed and transfected into cultured mouse bone marrow cells (BMCs). Male ICR mice were irradiated with a single dose of 9.5 Gy and then were injected with different agents through the tail vein. Stasis venous thrombosis was induced by inferior vena cava (IVC) ligation. Mice were sacrificed on the 1st, 3rd and 7th day post operation and the thrombi were removed, blotted the excess blood on it with filter paper and immediately weighed. P-selectin and d-Dimer were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS LRRFIP1 shRNA significantly suppressed the expression of LRRFIP1 in the thrombi. In contrast, low molecular weight heparin (LMWH) and negative shRNA exhibited little effect on the expression of LRRFIP1. LRRFIP1 shRNA, LMWH and negative shRNA inhibited the thrombus formation in vivo significantly. The plasma P-selectin and d-Dimer levels were significantly increased after IVC ligation. LRRFIP1 shRNA significantly decreased the plasma P-selectin and d-Dimer levels. However, LMWH and negative shRNA showed little effects on the levels of plasma P-selectin and d-Dimer. CONCLUSION LRRFIP1 shRNA might represent a promising prevention strategy for DVT.

Damage control orthopaedics in 53 cases of severe polytrauma who have mainly sustained orthopaedic trauma.

OBJECTIVE To discuss damage control orthopaedics in 53 cases of severe polytrauma who have mainly sustained orthopaedic trauma. METHODS The data of 53 cases of severe polytrauma who had mainly sustained orthopaedic trauma were retrospectively analyzed. And the methods and timing of damage control orthopaedics were discussed in this study. RESULTS We succeeded in rescuing the lives of all the 53 patients, and 38 patients returned to their former work. CONCLUSIONS Injury Severity Score (ISS(90)) should be 17 in severe polytrauma patients, but in severe polytrauma patients who have mainly sustained orthopaedic trauma, the ISS(90) of bone and joint injuries should be 16. We recommend that primary minimally-invasive external fracture stabilization should be made for extremities and pelvis in these patients to avoid additional surgical trauma and that definitive secondary fracture care should be performed after medical stabilization for these patients in intensive care unit (ICU).

The infection of Mycoplasma hominis after total knee replacement: Case report and literature review

The Mycoplasma hominis infection is a rare postoperative complication after joint replacement. Based on our knowledge, there were only two cases reported by Korea all over the world currently. A case of postoperative Mycoplasma hominis infection after total knee replacement in our hospital was reported in this article. It was confirmed through mass spectrometer and Mycoplasma cultivation and treated by the first stage debridement, polyethylene insert replacement, and then drainage and irrigation combined with sensitive antibiotics after the operation. We observed that the C reactive protein (CRP) level correlates with the development of disease, while the erythrocyte sedimentation rate (ESR) remains at a high level, indicating the relevance between the Mycoplasma hominis infection caused by knee joint replacement and CRP. This study aims to report the case and review relevant literature.

Damage control of multiple injuries headed by cervical spinal cord injury

OBJECTIVE To explore the strategy of damage control in clinical treatment of multiple injuries headed by cervical spinal cord injury. METHODS A retrospective analysis was performed in 32 patients. Cervical fractures associated with tetraplegia occurred in 18 patients, traumatic intervertebral disk hernia associated with tetraplegia in 2 patients, and cervical fractures and dislocation associated with tetraplegia in 12 patients. Seventeen cases were combined with craniocerebral injury, 7 combined with pulmonary contusion, multi-fractures of rib or hemopneumothorax, 2 combined with pelvic fracture and other 8 combined with fracture of limbs. The neural function was assessed by the American Spinal Injury Association (ASIA) scale. RESULTS Thirty-one patients were followed up for an average of 14 months. Of them, 10 got complete recovery, 13 obtained improvement of more than one ASIA grade, 8 did not improve, and 1 died. CONCLUSIONS For the emergency treatment of multiple injuries headed by cervical spinal cord injury, the damage control strategy is the principle to follow. The final operations are preferably performed within 5 to 10 days after injury so as to raise the successful rate of remedy.