Author Correction: Repair of bone defects with prefabricated vascularized bone grafts and double-labeled bone marrow-derived mesenchymal stem cells in a rat model.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

In-vivo anti-tumor activity of a novel poloxamer-based thermosensitive in situ gel for sustained delivery of norcantharidin.

In order to develop a novel norcantharidin (NCTD) delivery system with slow drug release and specific targeting characteristics, we have developed a Poloxamer-based NCTD thermosensitive in situ gel. The evaluation of the characteristics of this system using both in vitro and in vivo methods was previously reported. However, its anti-tumor activity in vivo is still not confirmed. Thus, the potential anti-tumor activity and relative mechanism were investigated in a murine H22 hepatoma model. Tumor-bearing mice were treated with different dose of NCTD thermosensitive in situ gel (3.3 mg/kg, 6.6 mg/kg, and 9.9 mg/kg, respectively by intra-tumor injection once every three days, totaling 5 injections per group. Control groups included untreated or NCTD injection (2.2 mg/kg, qd) or blank in situ gel. The expression of vascular endothelial growth factor (VEGF) and CD44 in tumor tissue was examined by immunohistochemistry (IHC) staining. Treatment with middle or high dose of NCTD thermosensitive in situ gel significantly induced tumor regression, inhibited VEGF and CD44 expression and improved survival of tumor-bearing mice. The efficacy of NCTD thermosensitive in situ gel is higher than that of free NCTD injection. Therefore, NCTD thermosensitive in situ gel is a novel NCTD delivery approach for chemotherapeutic treatment of cancer.

Repair of bone defects with prefabricated vascularized bone grafts and double-labeled bone marrow-derived mesenchymal stem cells in a rat model.

This study aims to investigate the repair of bone defects with prefabricated vascularized bone grafts and double-labeled bone marrow-derived mesenchymal stem cells (BMSCs) in a rat model. BMSCs were separated from rat bone marrow. LTR-CMVpro-RFP and LTR-CMVpro-GFP were transfected into the BMSCs for in vitro and in vivo tracking. BMSCs-RFP and BMSCs-GFP were induced into endothelial progenitor cells (EPCs) and osteoblasts (OBs). Rats were divided into five groups: Group A: in vitro prefabrication with EPCs-RFP + in vivo prefabrication with arteriovenous vascular bundle + secondary OBs-GFP implantation; Group B: in vitro prefabrication with EPCs-RFP + secondary OBs-GFP implantation; Group C: in vivo prefabrication with arteriovenous vascular bundle + secondary OBs-GFP implantation; Group D: implantation of EPCs-RFP + implantation of with arteriovenous vascular bundle + simultaneous OBs-GFP implantation; Group E: demineralized bone matrix (DBM) grafts (blank control). Among five groups, Group A had the fastest bone regeneration and repair, and the regenerated bone highly resembled normal bone tissues; Group D also had fast bone repair, but the repair was slightly slower than Group A. Therefore, in vitro prefabrication with EPCs-RFP plus in vivo prefabrication with arteriovenous vascular bundle and secondary OBs-GFP implantation could be the best treatment for bone defect.

Anti-tumor activity of SL4 against breast cancer cells: induction of G2/M arrest through modulation of the MAPK-dependent p21 signaling pathway.

SL4, a chalcone-based compound, has been shown to retard tumor invasion and angiogenesis by suppressing HIF1 activity and to induce apoptosis by promoting ROS release. Here, we report that SL4 is able to inhibit the proliferation of different types of breast cancer cell in vitro and in vivo by inducing G2/M cell cycle arrest. Our results showed that SL4 exhibited strong anti-proliferative activity in several human breast cancer cell lines, with IC50 values lower than 1.3 µM. Further studies indicated that SL4 induced G2/M arrest in these cell lines. Mechanistically, SL4 reduces the expression of cyclin A2 and cdc25C and decreases the activity of the cdc2/cyclin B1 complex. Notably, SL4 treatment resulted in an obvious increase in p21 mRNA and protein levels through activation of MAPK signaling pathways, but not the TGF-ß pathway. SP600125 and PD98059, specific inhibitors of JNK kinase and ERK kinase, significantly blocked the SL4-induced G2/M phase arrest and upregulation of p21. Furthermore, SL4 suppressed the growth of established breast tumors in nude mice through upregulation of p21 and downregulation of cdc25C, and displayed a good safety profile. Taken together, these findings demonstrate the potential value of SL4 as a novel multi-target anti-tumor drug candidate.

SYP-5, a novel HIF-1 inhibitor, suppresses tumor cells invasion and angiogenesis.

Hypoxia-inducible factor-1 (HIF-1) plays an essential role in carcinogenesis. The overexpression of HIF-1 induced by hypoxia is closely associated with metastasis, poor prognosis and high mortality. In this study, a novel HIF-1 inhibitor SYP-5 was first observed by the luciferase reporter assay. Western blots results showed SYP-5 inhibited hypoxia-induced upregulation of HIF-1. Moreover, the proteins of vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMP)-2 that are targets of HIF-1, were down-regulated by SYP-5. Furthermore, in the tube formation assay, SYP-5 suppressed angiogenesis induced by hypoxia and VEGF in vitro. Additionally, using Transwell and RTCA assays, we found that SYP-5 also retarded the Hep3B and Bcap37 cells migration and invasion induced by hypoxia and FBS. Last, we also detected the upstream pathways related to HIF-1 and found both PI3K/AKT and MAPK/ERK were involved in the SYP-5 mediated invasive inhibition of Bcap37 cells. These results indicates that SYP-5 inhibits tumor cell migration and invasion, as well as tumor angiogenesis, which are mediated by suppressing PI3K/AKT- and MAPK/ERK-dependent HIF-1 pathway. It suggests that SYP-5 might be a potential HIF-1 inhibitor as an anticancer agent.

Dorsal root ganglion neurons promote proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells.

Preliminary animal experiments have confirmed that sensory nerve fibers promote osteoblast differentiation, but motor nerve fibers have no promotion effect. Whether sensory neurons promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells remains unclear. No results at the cellular level have been reported. In this study, dorsal root ganglion neurons (sensory neurons) from Sprague-Dawley fetal rats were co-cultured with bone marrow mesenchymal stem cells transfected with green fluorescent protein 3 weeks after osteogenic differentiation in vitro, while osteoblasts derived from bone marrow mesenchymal stem cells served as the control group. The rat dorsal root ganglion neurons promoted the proliferation of bone marrow mesenchymal stem cell-derived osteoblasts at 3 and 5 days of co-culture, as observed by fluorescence microscopy. The levels of mRNAs for osteogenic differentiation-related factors (including alkaline phosphatase, osteocalcin, osteopontin and bone morphogenetic protein 2) in the co-culture group were higher than those in the control group, as detected by real-time quantitative PCR. Our findings indicate that dorsal root ganglion neurons promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells, which provides a theoretical basis for in vitro experiments aimed at constructing tissue-engineered bone.

Synovial fluid omentin-1 levels are inversely correlated with radiographic severity of knee osteoarthritis.

OBJECTIVE: The purpose of this study was to demonstrate omentin-1 levels in serum and synovial fluid (SF) of patients with knee osteoarthritis (OA) and to investigate their correlation with radiographic disease severity. METHODS: One hundred and ninety-seven patients with OA and 65 sex- and age-matched healthy controls were enrolled in this study. The radiographic disease severity of OA was assessed by the Kellgren- Lawrence (KL) grading system. The omentin-1 levels in serum and SF were determined by enzyme-linked immunosorbent assay. RESULTS: There were no significant differences in serum omentin-1 levels between patients with OA and healthy controls (P>0.05). There were also no significant differences in serum omentin-1 levels among patients with OA with different KL grades (P>0.05). However, SF omentin-1 levels decreased significantly as the KL grades increased (KL grade 4 < KL grade 3 < KL grade 2; all P<0.01) in the patients with OA. Furthermore, SF omentin-1 levels were negatively correlated with KL grades (r=-0.643; P<0.001). Multinomial logistic regression analysis revealed that there was still a negative correlation between the SF omentin-1 levels and the KL grades after adjusting for confounding factors (P<0.001). CONCLUSIONS: Synovial fluid omentin-1 levels showed an independent and negative correlation with radiographic severity of the disease in patients with knee OA. Omentin-1 in SF might serve as a potential biomarker for reflecting the degenerative process of primary knee OA.

Association of FAS and FAS ligand polymorphisms with the susceptibility and severity of lumbar disc degeneration in Chinese Han population.

CONTEXT: Apoptosis is involved in the mechanism of lumbar disc degeneration (LDD). OBJECTIVE: We aim to determine whether the polymorphisms of FAS and FASL are associated with the presence and severity of LDD. METHODS: A total of 348 patients with LDD and 215 healthy controls were genotyped. RESULTS: Patients with LDD showed higher frequency of-1377GA and AA, as well as-844CT and TT genotypes than normal controls. These genotypes were found to be associated with the risk of higher grades of LDD. CONCLUSION: The polymorphisms of FAS and FASL may be associated with the presence and severity of LDD.

Amide-linkage formed between ammonia plasma treated poly(D,L-lactide acid) scaffolds and bio-peptides: enhancement of cell adhesion and osteogenic differentiation in vitro.

The surface characteristics of scaffolds for bone tissue engineering must support cell adhesion, migration, proliferation, and osteogenic differentiation. In the study, poly(D,L-lactide acid) (PDLLA) scaffolds were modified by combing ammonia (NH(3) ) plasma pretreatment with Gly-Arg-Gly-Asp-Ser (GRGDS)-peptides coupling technologies. The x-ray photoelectron spectroscopy (XPS) survey spectra showed the peak of N1s at the surface of NH(3) plasma pretreated PDLLA, which was further raised after GRGDS conjugation. Furthermore, N1s and C1s in the high-resolution XPS spectra revealed the presence of -C=N(imine), -C-NH-(amine), and -C=O-NH- (amide) groups. The GRGDS conjugation increased amide groups and decreased amine groups in the plasma-treated PDLLA. Confocal microscope and high performance liquid chromatography verified the anchored peptides after the conjugation process. Bone marrow mesenchymal stem cells were co-cultured with scaffolds. Fluorescent microscope and scanning electron microscope photographs revealed the best cell adhesion in NH(3) plasma pretreated and GRGDS conjugated scaffolds, and the least attachment in unmodified scaffolds. Real-time PCR demonstrated that expression of osteogenesis-related genes, such as osteocalcin, alkaline phosphatase, type I collagen, bone morphogenetic protein-2 and osteopontin, was upregulated in the single NH(3) plasma treated and NH(3) plasma pretreated scaffolds following GRGDS conjugation. The results show that NH(3) plasma treatment promotes the conjugation of GRGDS peptides to the PDLLA scaffolds via the formation of amide linkage, and combination of NH(3) plasma treatment and peptides conjugation may enhance the cell adhesion and osteogenic differentiation in the PDLLA scaffolds. © 2011 Wiley Periodicals, Inc. Biopolymers 95: 682-694, 2011.

[Effects of bioactive modification of poly-D,L-lactide acid scaffolds on the biological behaviors of the seed cells].

OBJECTIVE: To study the changes in the biological behavior of bone marrow mesenchymal stem cells (BMSCs) transfected with red fluorescent protein by lentivirus (RFP-BMSCs) seeded on in poly-D, L-lactide acid (PDLLA) scaffolds with bioactive modification by ammonia plasma and Gly-Arg-Gly-Asp-Ser (GRGDS) in vitro. METHODS: Circular sheets of PDLLA scaffolds (8 mm in diameter and 1 mm in thickness) were prepared and aminated with PDLLA (group A) or modified with the peptide conjugate A/PDLLA (group PA), with untreated PDLLA as the control (group P). The RFP-BMSCs were seeded on the scaffold materials and their proliferation and metabolic activity were detected using CyQuant NF and Alamar blue staining. The mineralization on the scaffolds was observed using calcein fluorescent dye under a fluorescent microscope. The adhesion and proliferation of RFP-BMSCs were observed by fluorescent microscope, and scanning electron microscope (SEM) was used to confirm the observed adhesion of the seed cells. RESULTS: The RFP-BMSCs seeded on the 3 scaffolds all showed proliferative activity at different time points after cell seeding, and the cell numbers decreased significantly in the order of PA>A>P (P<0.001). The cell number was significantly greater in group PA than in group A at all the time points except for days 10 (P=0.077) and 12 (P=0.491), and gradually became similar with the passage of time. The metabolic changes of the cells follow a similar pattern of cell proliferation. RFP-BMSCs showed more active proliferation in group A and group PA than in group P. On days 14 and 21, the intensity of green fluorescence decreased in the order of group PA, A and P. The RFP-BMSCs showed better adhesion in group PA than in group A, and the cells in group P appeared more scattered under scanning electron microscope. CONCLUSION: Bioactive modification of PDLLA by ammonia treatment and conjugation with GRGDS peptides may promotes the adhesion, proliferation, metabolism and mineralization of RFP-BMSCs seeded on PDLLA scaffolds.

[Three-dimensional visualization of virtual surgery for intertrochanteric fractures].

OBJECTIVE: To establish a computer-aided three-dimensional visualization operation simulation system based on Mimics and Unigraphics NX software to provide reliable evidence for accurate preoperative surgical planning. METHODS: The preoperative CT scans of 5 patients with intertrochanteric fractures were used for three-dimensional reconstruction of intertrochanteric fractures using Mimics software. Three-dimensional reconstruction of the surgical instruments was carried out using the modeling function of Unigraphics NX software, whose assembly function was used to visualize the simulates internal fixations of intertrochanteric fractures with dynamic hip screw (DHS) system. The operative procedures simulated by Unigraphics NX were analyzed preoperatively. RESULTS: The virtual surgery procedures were clearly and vividly visualized in three dimensions. The fracture reduction and surgical effects could be predicted using this system. CONCLUSIONS: This system of three-dimensional visualization of virtual surgery for intertrochanteric fractures has important values in surgical planning, risk assessment and clinical training, and can help improve the reliability and outcome of orthopedic surgery.

[Establishment of a digital Evans-Jensen classification model of femoral intertrochanteric fracture].

OBJECTIVE: To establish a digitized Evans-Jensen classification model of femoral intertrochanteric fracture. METHODS: The hip of a healthy male volunteer was examined with 64-slice spiral CT, and the data were processed using Mimics 10.01 software to reconstruct the proximal femur model. According to Evans-Jensen classification criteria of femoral intertrochanteric fracture, each type of fracture model was simulated. Five orthopedic surgeons and 10 medical students undertook the preliminary evaluation of the digital fracture model. RESULTS: The digital fracture model is intuitive, three-dimensional, and realistic with good visual effect. The fracture could be observed and charted from optional direction and angle. The corresponding animation allowed 360 degrees rotation. Evaluation by the 4 orthopedic surgeons and 10 medical students confirmed that the digital fracture model was intuitive and easy to understand. CONCLUSION: The digital model of femoral intertrochanteric fracture is intuitive, three-dimensional, realistic and dynamic, and may help in clinical practice and medical teaching.