A bioactive material with dual integrin-targeting ligands regulates specific endogenous cell adhesion and promotes vascularized bone regeneration in adult and fetal bone defects.

Significant progress has been made in designing bone materials capable of directing endogenous cells to promote vascularized bone regeneration. However, current strategies lack regulation of the specific endogenous cell populations for vascularized bone regeneration, thus leading to adverse tissue formation and decreased regenerative efficiency. Here, we engineered a biomaterial to regulate endogenous cell adhesion and promote vascularized bone regeneration. The biomaterial works by presenting two synthetic ligands, LLP2A and LXW7, explicitly targeting integrins α4ß1 and αvß3, respectively, expressed on the surfaces of the cells related to bone formation and vascularization, such as mesenchymal stem cells (MSCs), osteoblasts, endothelial progenitor cells (EPCs), and endothelial cells (ECs). In vitro, the LLP2A/LXW7 modified biomaterial improved the adhesion of MSCs, osteoblasts, EPCs, and ECs via integrin α4ß1 and αvß3, respectively. In an adult rat calvarial bone defect model, the LLP2A/LXW7 modified biomaterial enhanced bone formation and vascularization by synergistically regulating endogenous cells with osteogenic and angiogenic potentials, such as DLX5+ cells, osteocalcin+ cells, CD34+/CD45- cells and CD31+ cells. In a fetal sheep spinal bone defect model, the LLP2A/LXW7 modified biomaterial augmented bone formation and vascularization without any adverse effects. This innovative biomaterial offers an off-the-shelf, easy-to-use, and biologically safe product suitable for vascularized bone regeneration in both fetal and adult disease environments.

[Clinical effects of tranexamic acid in arthroscope for femoroacetabular impingement].

OBJECTIVE: To evaluate the clinical effects of tranexamic acid in arthroscope for femoroacetabular impingement. METHODS: Totally 34 patients (34 hips) with femoroacetabular impingement underwent hip arthroscopy from June 2016 to December 2018, were randomly divided into two groups named as tranexamic acid group and control group, 17 patients in each group. In TXA group, there were 10 males and 7 females, aged from 20 to 49 years old with an average of (32.1±7.6) years old;15 mg/kg TXA was intravenous drops before operation incision performed at 10 min. In control group, there were 11 males and 6 females, aged from 20 to 49 years old with an average of (30.9±6.2) years old;100 ml normal saline was intravenous drops before operation incision performed at 10 min. Introopertaive and total bloodloss between two groups were compared. Visual analogue scale (VAS) at 3 and 7 days after opertaion were used to evaluate pain relief of hip joint. Modified Harris Hip Score(mHHS) of hip joint at 3, 6, 9 and 12 weeks after oeprtaion were applied to evaluate clinical effects. RESULTS: All patients were obtained follow up over 12 weeks. Incision healed well without infection and deep vein thrombosis. There were no statistical difference in opertaion time bewteen two groups(P>0.05) . Total blood loss and introopertaive blood loss in TXA group were (0.47±0.20) L and (0.18±0.08) L, while (0.66±0.22) L and (0.24±0.01) L in control group;there were statical differences between two groups (P<0.05). There were no dierences in VAS before opertaion and 7 days after opertaion between two groups (P>0.05);VAS at 3 days after opertaion in TXA group was 2.35±1.12 and 3.12±0.70 in control group, and had difference (P< 0.05). There were significance in VAS at 3 and 7 days after opertaion compared with preopertaive between two groups (P< 0.05). Postopertaive mHHS in TXA group at 3 and 6 weeks were 87.72±1.95 and 91.92±2.32, respectively;while 84.08±1.21 and 89.77±3.30 in control group;there were difference between two groups at 3 and 6 weeks after operation (P<0.05);there were no significant difference in mHHS between two groups at 9 and 12 weeks after operation(P>0.05). CONCLUSION: Preoperative application of tranexamic acid could effectively reduce blood loss in arthroscopy for femoroacetabular impingement, thereby improving surgical field of vision, reducing difficulty of surgical operation, which could promote early and rapid rehabilitation of hip function.

Core decompression and implantation of calcium phosphate cement/Danshen drug delivery system for treating ischemic necrosis of femoral head at Stages I, II and III of antigen reactive cell opsonization.

OBJECTIVE: To introduce a new method using calcium phosphate cement/Danshen drug delivery system for treating ischemic necrosis of the femoral head and evaluate its curative effect. METHODS: From May 2000 to June 2005, 48 adult patients (54 hips) with ischemic necrosis of the femoral head at Stages I, II and III of antigen reactive cell opsonization (ARCO) were treated with implantation of calcium phosphate cement/Danshen drug delivery system in the involved femoral head. The operation consisted of removal of the necrotic bone under weight-loading cartilage and the implantation of phosphate cement/Danshen drug delivery system, and all manipulations were made percutaneously through a bone tunnel in the trochanter. The functions of the hip joint were evaluated and X-ray films were taken preoperatively and postoperatively. RESULTS: Postoperative follow-up was 45.5 months on average, ranging from 27 to 78 months. According to the evaluation criterion of "Dandong 1995" for therapeutic effect of adult ischemic necrosis of the femoral head, the therapeutic effects were excellent in 33 hips, good in 17, fair in 3 and poor in 1, with the excellent and good rate of 92.6%. CONCLUSIONS: This method is relatively simple with little invasion. It not only improves the microcirculation of the femoral head by local application of traditional Chinese medicine, but also provides mechanic buttress in the weight-loading area to prevent collapse during repairing, which is beneficial to repair and reconstruction of femoral head. It may be a choice of minimal invasion surgery for ischemic necrosis of the femoral head at Stages I, II and III of ARCO.

Autologous platelet lysate local injections for the treatment of refractory lateral epicondylitis.

BACKGROUND: The purpose of this study was to investigate the efficacy and safety of autologous platelet lysate (APL) local injections in reducing pain and improving function in patients with refractory lateral epicondylitis. METHODS: A total of 56 patients with refractory lateral epicondylitis were enrolled in this study. All the patients received three injections in one course of treatment. Subjective assessments include visual analog scale (VAS) pain score and Mayo elbow score before injection (baseline) and at 1, 6, and 12 months after injection. RESULTS: Significant differences were observed in VAS and Mayo scores at baseline and at 1, 6, and 12 months after injection. Overall, the injections of APL improved local symptoms and all the patients recovered to normal elbow function with 12 months follow-up. CONCLUSIONS: Local injections of APL resulted in favorable clinical outcomes for the treatment of lateral epicondylitis. APL could be clinically effective in the treatment of lateral epicondylitis.

Autologous platelet lysates local injections for treatment of tibia non-union with breakage of the nickelclad: a case report.

BACKGROUND: Nonunions of the tibia represent challenging orthopedic problems, which require the surgeon to analyze numerous factors and choose an appropriate treatment. This article presents a case report of tibia and fibula fracture patient who failed the internal fixation surgery and successfully recovered after one course of percutaneous autologous platelet lysates injection. CASE DESCRIPTION: The patient received an internal nickelclad breakage at 9 months post-surgery but reluctant to accept a second surgery, then autologous platelet lysates (APL) injection which is a less invasive method was recommended. The injections were carried once a week for three times. Radiologic evaluation was conducted every month until recovery. DISCUSSION AND EVALUATION: To the best of our knowledge, this is the first reported case of tibia delayed union with breakage of the plate resolved with APL injection. Improved clinical evidence was observed at 4 and 6 months after injection. The patient got good bony union at 8 months post-injection. The patient didn't feel any discomfort postinjection, no complications such as infection, refracture etc. were observed. CONCLUSIONS: APL percutaneous injection could be a new therapeutic option for the treatment of nonunion or delayed healing fractures.

Improved workability of injectable calcium sulfate bone cement by regulation of self-setting properties.

Calcium sulfate hemihydrate (CSH) powder as an injectable bone cement was prepared by hydrothermal synthesis of calcium sulfate dihydrate (CSD). The prepared materials showed X-ray diffraction peaks corresponding to the CSH structure without any secondary phases, implying complete conversion from CSD phase to CSH phase. Thermogravimetric (TG) analyses showed the crystal water content of CSH was about 6.0% (wt.), which is near to the theoretic crystal water value of CSH. From scanning electron microscopy (SEM) micrographs, sheet crystal structure of CSD was observed to transform into rod-like crystal structure of CSH. Most interesting and important of all, CSD as setting accelerator was also introduced into CSH powder to regulate self-setting properties of injectable CSH paste, and thus the self-setting time of CSH paste can be regulated from near 30 min to less than 5 min by adding various amounts of setting accelerator. Because CSD is not only the reactant of preparing CSH but also the final solidified product of CSH, the setting accelerator has no significant effect on the other properties of materials, such as mechanical properties. In vitro biocompatibility and in vivo histology studies have demonstrated that the materials have good biocompatibility and good efficacy in bone regeneration. All these will further improve the workability of CSH in clinic applications.

[Clinical study on the early reconstruction of complex acetabular fractures].

OBJECTIVE: To explore the best opportunity of structure reconstruction for complex acetabular fracture in order to provide the accurate time for clinical operative treatment. METHODS: Complex acetabular fracture patients were divided into experimental group (93 cases, 96 hips) and control group (98 cases, 101 hips) randomly according to the operative time. The operation of patients were done respectively at the 7th, 10th day after injury in experimental group and control group. The operative time, the excellent and good rate of reduction,the postoperative complications,the joint function (ache to walk,joint activity),the SF-36 were evaluated. RESULTS: (1) The operative time of experimental group was obviously shorter than control group according to different fracture classification. (2) According to the standard of Matta' joint function and X-ray, the experimental group was better than control group. (3) The excellent and good rate of reduction in experimental group was obviously higher than control group, according to CT scan before operation and after operation. CONCLUSION: The early structure reconstruction of complex acetabular fracture can obviously decrease operative time and complications, increase the rate of operative reduction.