Correction to: "Comparative repair capacity of knee osteochondral defects using regenerated silk fiber scaffolds and fibrin glue with/without autologous chondrocyes during 36 weeks in rabbit model.

The published online of the original version contains mistakes.

Comparative restoration of acute liver failure by menstrual blood stem cells compared with bone marrow stem cells in mice model.

BACKGROUND AIMS: The application of menstrual blood stem cells (MenSCs) in regenerative medicine is gaining increasing attention. The aim of this study was to investigate the therapeutic potential of MenSCs compared with bone marrow-derived stem cells (BMSCs) in an animal model of CCl4-induced acute hepatic failure. METHODS: Injured Balb/C mice were divided into multiple groups and received MenSCs, BMSCs or hepatocyte progenitor-like (HPL) cells derived from these cells. RESULTS: Tracking of green fluorescent protein-labeled cells showed homing of cells in injured areas of the liver. In addition, the liver engraftment of MenSCs was shown by immunofluorescence staining using anti-human mitochondrial antibody. Microscopically examination, periodic acid-Schiff and Masson's trichrome staining of liver sections demonstrated the considerable liver regeneration post-cell therapy in all groups. Assessment of serum parameters including aspartate aminotransferase, alanine aminotransferase, total bilirubin, urea and cholesterol at day 7 exhibited significant reduction, such that this downward trend continued significantly until day 30. The restoration of liver biochemical markers, changes in mRNA levels of hepatic markers and the suppression of inflammatory markers were more significant in the MenSC-treated group compared with the BMSC-treated group. On the other hand, HPL cells in reference to undifferentiated cells had better effectiveness in the treatment of the acute liver injury. CONCLUSIONS: Our data show that MenSCs may be considered an appropriate alternative stem cell population to BMSCs for treatment of acute liver failure.

Bladder smooth muscle cells on electrospun poly(ε-caprolactone)/poly(l-lactic acid) scaffold promote bladder regeneration in a canine model.

Engineering of urinary bladder has been the focus of numerous studies in recent decade. Novel biomaterials, innovative fabrication methods and various modification processes of scaffolds are the critical issues to find supportive matrices. Supportive characteristics of electrospun PCL/PLLA nano-scaffold for bladder augmentation in canine model and the role of bladder cells in regeneration process were appraised. Electrospun PCL/PLLA was fabricated by co-electrospinning of PCL and PLLA. Bladder cells were isolated and transduced with lentiviral particles encoding eGFP and JRed proteins. Electrospun PCL/PLLA was seeded with different bladder cells individually or in co-culture condition. Cell-free and cell-seeded electrospun PCL/PLLA scaffolds (10cm2) were surgically implanted in bladders of eight female dogs for three months. To evaluate bladder regeneration, the dogs were sacrificed and their bladders were examined macroscopically and microscopically for presence of tracking proteins, expression of cell-specific markers and histological attributes of regenerated tissues. All animals survived the experiment with no complication. In smooth muscle transplanted group complete regeneration and covering of scaffold were observed. Other groups revealed partial regeneration. A well-developed layer of urothelium was formed in all groups in regenerated parts. Smooth muscle transplanted group showed the most developed muscle layer. Regenerated tissue demonstrated typical expression of cell-specific markers. No expression of eGFP and JRed was observed. Electrospun PCL/PLLA scaffold with proper handling, suture retention, nano-sized surface features, maintenance of normal phenotype of cells and minimal adverse effects in body can be a supportive substrate for bladder wall regeneration when seeded with bladder smooth muscle cells.

Comparative repair capacity of knee osteochondral defects using regenerated silk fiber scaffolds and fibrin glue with/without autologous chondrocytes during 36 weeks in rabbit model.

The reconstruction capability of osteochondral (OCD) defects using silk-based scaffolds has been demonstrated in a few studies. However, improvement in the mechanical properties of natural scaffolds is still challengeable. Here, we investigate the in vivo repair capacity of OCD defects using a novel Bombyx mori silk-based composite scaffold with great mechanical properties and porosity during 36 weeks. After evaluation of the in vivo biocompatibility and degradation rate of these scaffolds, we examined the effectiveness of these fabricated scaffolds accompanied with/without autologous chondrocytes in the repair of OCD lesions of rabbit knees after 12 and 36 weeks. Moreover, the efficiency of these scaffolds was compared with fibrin glue (FG) as a natural carrier of chondrocytes using parallel clinical, histopathological and mechanical examinations. The data on subcutaneous implantation in mice showed that the designed scaffolds have a suitable in vivo degradation rate and regenerative capacity. The repair ability of chondrocyte-seeded scaffolds was typically higher than the scaffolds alone. After 36 weeks of implantation, most parts of the defects reconstructed by chondrocytes-seeded silk scaffolds (SFC) were hyaline-like cartilage. However, spontaneous healing and filling with a scaffold alone did not eventuate in typical repair. We could not find significant differences between quantitative histopathological and mechanical data of SFC and FGC. The fabricated constructs consisting of regenerated silk fiber scaffolds and chondrocytes are safe and suitable for in vivo repair of OCD defects and promising for future clinical trial studies.

Comparative evaluation of in vivo biocompatibility and biodegradability of regenerated silk scaffolds reinforced with/without natural silk fibers.

Nowadays, exceptional advantages of silk fibroin over synthetic and natural polymers have impelled the scientists to application of this biomaterial for tissue engineering purposes. Recently, we showed that embedding natural degummed silk fibers in regenerated Bombyx mori silk-based scaffold significantly increases the mechanical stiffness, while the porosity of the scaffolds remains the same. In the present study, we evaluated degradation rate, biocompatibility and regenerative properties of the regenerated 2% and 4% wt silk-based composite scaffolds with or without embedded natural degummed silk fibers within 90 days in both athymic nude and wild-type C57BL/6 mice through subcutaneous implantation. In all scaffolds, a suitable interconnected porous structure for cell penetration was seen under scanning electron microscopy. Compressive tests revealed a functional relationship between fiber reinforcement and compressive modulus. In addition, the fiber/fibroin composite scaffolds support cell attachment and proliferation. On days 30 to 90 after subcutaneous implantation, the retrieved tissues were examined via gross morphology, histopathology, immunofluorescence staining and reverse transcription-polymerase chain reaction as shown in Figure 1. Results showed that embedding the silk fibers within the matrix enhances the biodegradability of the matrix resulting in replacement of the composite scaffolds with the fresh connective tissue. Fortification of the composites with degummed fibers not only regulates the degradation profile but also increases the mechanical performance of the scaffolds. This report also confirmed that pore size and structure play an important role in the degradation rate. In conclusion, the findings of the present study narrate key role of additional surface area in improving in vitro and in vivo biological properties of the scaffolds and suggest the potential ability of these fabricated composite scaffolds for connective tissue regeneration. spjba;30/6/793/FIG10885328215601925F1fig1-0885328215601925Figure 1.Illustrative summary of the main methods and findings.RS: regenerated silk; RSF: regenerated fibroin/ silk fiber composite scaffolds; H&E: Hematoxylin and eosin; COX-1: Cyclooxygenase.

Effects of treatment with platinum azidothymidine and azidothymidine on telomerase activity and bcl-2 concentration in hepatocellular carcinoma- induced rats.

BACKGROUND: Telomerase activity increases in cancer cells. Bcl-2 is an antiapoptotic factor that its concentration grows in many cancer cells including hepato-cellular carcinoma cells. In this study, an attempt was made to investigate the effects of a new synthetic compound, platinum azidothymidine (Pt-AZT) on treatment of rats with Hepatocellular Carcinoma (HCC) and to compare its effects with azidothymidine (AZT) in alteration of telomerase activity and Bcl-2 concentration in HCC. METHODS: Healthy adult male Wistar rats (n = 100) were randomly divided into 4 groups (A, B, C, and D). Group A contained 25 healthy rats and was considered as the control group. Liver preneoplastic lesions were induced in remaining animals (n = 75) using Solt-Farber resistant hepatocyte protocol. These animals were randomly allocated in groups B, C and D. Group B was negative control (untreated), groups C and D were treated by intraperitoneal injection (IP) of Pt-AZT (0.9 mg/kg/day) and AZT (0.3 mg/kg/day), respectively for 14 days. After the treatment period, telomerase activity and Bcl-2 concentration were determined in the rats' liver. RESULTS: No HCC was developed in group A, but tumors were present in all other groups. Telomerase activity and Bcl-2 concentration were significantly lower in group C compared to groups B (0.159±0.06 vs. 0.577±0.116 IU/L, p < 0.001, respect-ively and 0.931±0.388 vs. 3.94±0.74 ng/ml, p < 0.001, respectively). Similar results were observed in comparison with group D (0.331±0.06 vs. 0.577±0.116 IU/L, p < 0.001, respectively and 0.931±0.388 vs. 2.94±0.594 ng/ml, respectively). There was a significant negative correlation between telomerase activity and Bcl-2 concentration only in untreated cancer group (p = 0.034). CONCLUSION: In this study, higher anticancer activity of Pt-AZT in comparison to AZT was demonstrated. It effectively inhibits the growth of liver tumor in rats through extending apoptosis.

Expression of vimentin filaments in canine malignant mammary gland tumors: A simulation of clinicopathological features of human breast cancer.

Canine malignant mammary gland tumors (CMMGTs) are the most common malignancies observed in females. Several biological similarities have been reported between CMMGTs and human breast cancer (HBC). The present study aimed to assess the correlation of vimentin filaments overexpression, as part of the process of epithelial-mesenchymal transition (EMT) and the clinicopathological characteristics in CMMGTs. The clinicopathological characteristics of 42 CMMGTs were collected. Paraffin-embedded blocks underwent immunohistochemistry staining, which was performed using vimentin (to assess the evolution of the EMT process), Ki-67 (for evaluation of tumor proliferation) and cluster of differentiation 34 (CD34) (for evaluation of angiogenesis) antibodies. The tumor stage, grade, vascular invasion, margin status, rate of expression of the vimentin filaments, microvessel density-CD34 and proliferation rate data were obtained. Finally, the association between the expression of the vimentin filaments and those parameters was resolved statistically. A significant association was shown between the overexpression of the vimentin filaments and tumor size (r=0.71, P=0.03), tumor grade (r=0.80, P=0.021), angiogenesis (r=0.57, P=0.043), proliferation coefficient (r=0.06, P=0.001) and vascular invasion (r=0.76, P=0.043). Vimentin overexpression did not statistically correlate with the tumor stage or the margin status. Similar to the findings of the present study, certain recent studies have indicated that vimentin filament expression in HBC and CMMGTs is associated with the severity of cancer. Thus, spontaneous canine mammary tumor models appear to be an appropriate animal model for breast cancer research, and the results of the present study could aid to reinforce the association.

A high affinity monoclonal antibody recognizing the light chain of human coagulating factor VII.

Factor VII (FVII) is a serine protease-coagulating element responsible for the initiation of an extrinsic pathway of clot formation. Here we generated and characterized a high affinity monoclonal antibody that specifically recognizes human FVII. Recombinant human FVII (rh-FVII) was used for the production of a monoclonal antibody using BALB/c mice. The specificity of the antibody was determined by Western blot using plasma samples from human, mouse, sheep, goat, bovine, rabbit, and rat. Furthermore, the antibody was used to detect transiently expressed rh-FVII in BHK21 cell line using Western blot and sandwich ELISA. A mouse IgG1 (kappa chain) monoclonal antibody clone 1F1-B11 was produced against rh-FVII. The affinity constant (K(aff)) of the antibody was calculated to be 6.4×10(10) M(-1). The antibody could specifically recognize an epitope on the light chain of hFVII, with no reactivity with factor VII from several other animals. In addition, transiently expressed rh-FVII in BHK21 cells was recognized by 1F1-B11. The high affinity as well as the specificity of 1F1-B11 for hFVII will facilitate the affinity purification of hFVII and also production of FVII deficient plasma and minimizes the risk of bovine FVII contamination when fetal bovine serum-supplemented media are used for production and subsequent purification of rh-FVII.