Injectable hydrogel scaffold incorporating microspheres containing cobalt-doped bioactive glass for bone healing.

Injectable in situ-forming scaffolds that induce both angiogenesis and osteogenesis have been proven to be promising for bone healing applications. Here, we report the synthesis of an injectable hydrogel containing cobalt-doped bioactive glass (BG)-loaded microspheres. Silk fibroin (SF)/gelatin microspheres containing BG particles were fabricated through microfluidics. The microspheres were mixed in an injectable alginate solution, which formed an in situ hydrogel by adding CaCl2. The hydrogel was evaluated for its physicochemical properties, in vitro interactions with osteoblast-like and endothelial cells, and bone healing potential in a rat model of calvarial defect. The microspheres were well-dispersed in the hydrogel and formed pores of >100 µm. The hydrogel displayed shear-thinning behavior and modulated the cobalt release so that the optimal cobalt concentration for angiogenic stimulation, cell proliferation, and deposition of mineralized matrix was only achieved by the scaffold that contained BG doped with 5% wt/wt cobalt (A-S-G5Co). In the scaffold containing higher cobalt content, a reduced biomimetic mineralization on the surface was observed. The gene expression study indicated an upregulation of the osteogenic genes of COL1A1, ALPL, OCN, and RUNX2 and angiogenic genes of HIF1A and VEGF at different time points in the cells cultured with the A-S-G5Co. Finally, the in vivo study demonstrated that A-S-G5Co significantly promoted both angiogenesis and osteogenesis and improved bone healing after 12 weeks of follow-up. These results show that incorporation of SF/gelatin microspheres containing cobalt-doped BG in an injectable in situ-forming scaffold can effectively enhance its bone healing potential through promotion of angiogenesis and osteogenesis.

Suppression of SOCS3 expression in macrophage cells: Potential application in diabetic wound healing.

Impaired polarization of M1 to M2 macrophages has been reported in diabetic wounds. We aimed to improve this polarization by down-regulation of expression of the "Suppressor of Cytokine Signaling 3" (SOCS3) gene in macrophages. Two oligodeoxynucleotide (ASO) sequences were designed against SOC3 mRNA and were loaded to mannosylated-polyethyleneimine (Man-PEI). The optimum N/P ratio for Man-PEI-ASO was determined to be 8 based on loading efficiency, particle size, zeta potential, cellular uptake and cytotoxicity assay. pH stability of ASO in Man-PEI-ASO and its protection from DNase I was confirmed. After in vitro treatment of macrophages with Man-PEI-ASO, SOCS3 was downregulated, SOCS1 upregulated, and SOCS1/SOCS3 ratio increased. Also, expressions of macrophage markers of M2 (IL-10, Arg1, CD206) increased and those of M1 (IL-1ß, NOS2, CD68) decreased, and secretion of pro-inflammatory cytokines (TNF-α and IL-1ß) decreased while that of anti-inflammatory cytokine IL-4 increased. All suggested a polarization into M2 phenotype. Finally, the Man-PEI-ASO was loaded in hydrogel and applied to a diabetic wound model in mice. It improved the healing to the level observed in non-diabetic wounds. We show that using antisense sequences against SOC3 mRNA, macrophage polarization could be directed into the M2 phenotype and healing of diabetic wound could be highly improved.

Epithelial cells/progenitor cells in developing human lower respiratory tract: Characterization and transplantation to rat model of pulmonary injury.

Introduction: For cell-based therapies of lung injury, several cell sources have been extensively studied. However, the potential of human fetal respiratory cells has not been systematically explored for this purpose. Here, we hypothesize that these cells could be one of the top sources and hence, we extensively updated the definition of their phenotype. Methods: Human fetal lower respiratory tissues from pseudoglandular and canalicular stages and their isolated epithelial cells were evaluated by immunostaining, electron microscopy, flow cytometry, organoid assay, and gene expression studies. The regenerative potential of the isolated cells has been evaluated in a rat model of bleomycin-induced pulmonary injury by tracheal instillation on days 0 and 14 after injury and harvest of the lungs on day 28. Results: We determined the relative and temporal, and spatial pattern of expression of markers of basal (KRT5, KRT14, TRP63), non-basal (AQP3 and pro-SFTPC), and early progenitor (NKX2.1, SOX2, SOX9) cells. Also, we showed the potential of respiratory-derived cells to contribute to in vitro formation of alveolar and airway-like structures in organoids. Cell therapy decreased fibrosis formation in rat lungs and improved the alveolar structures. It also upregulated the expression of IL-10 (up to 17.22 folds) and surfactant protein C (up to 2.71 folds) and downregulated the expression of TGF-ß (up to 5.89 folds) and AQP5 (up to 3.28 folds). Conclusion: We provide substantial evidence that human fetal respiratory tract cells can improve the regenerative process after lung injury. Also, our extensive characterization provides an updated phenotypic profile of these cells.

Cross-linked acellular lung for application in tissue engineering: Effects on biocompatibility, mechanical properties and immunological responses.

The concept of providing tissue engineering scaffolds with natural physical properties and minimal immunogenicity has not been systematically approached for the lungs yet. Here, the rat acellular lung tissue (ALT) was cross-linked to provide either EDC/NHS cross-linked tissue (EDC/NHS-CLT) or tannic acid cross-linked tissue (TA-CLT). Young's modulus revealed that EDC/NHS-CLT had mechanical properties similar to the native lung and culture of lung mesenchymal cells showed a higher potential of cell proliferation on EDC/NHS-CLT versus TA-CLT and ALT. The in vitro immunogenicity tests showed a strong induction of T-cell proliferation by TA-CLT and an attenuated macrophage induction by TA-CLT. Processed rat lungs were implanted xenogenically into the mouse peritoneal cavity and the host-implant interactions showed that tannic acid is not released from TA-CLT in a physiologically effective dose. The profile of peritoneal fluid proinflammatory (TNFα, IL-1ß, IL-12p70 and IL-17) and anti-inflammatory (IL-10 and TGFß1) cytokines, and CD3+ T-lymphocytes and CD11b+ macrophages revealed that apart from induction of high levels of IL-17 during the first week and IL-10 during the second to third weeks after implantation by TA-CLT, other indicators of immune reactions to cross-linked tissues were not significantly different from ALT. Also, a high fibrotic reaction to TA-CLT was observed on the weeks 2-3, but alveolar structures were preserved in EDC/NHS-CLT. Our findings show that by controlled EDC/NHS cross-linking, an acellular lung scaffold could be provided with mechanical properties similar to native lung, which promotes mesenchymal lung cells proliferation and does not stimulate recipient's immune system more than a non-cross-linked tissue.

Association of Endonuclease G Gene Variants with Cardiovascular Disease Risk Factors.

BACKGROUND: Cardiovascular disease (CVD) is a leading cause of death, supporting the need for the identification of novel biomarkers as risk stratification factors. Endonuclease G (ENDOG) has recently been suggested to be a novel determinant of cardiac hypertrophy and mitochondrial function, and plays an important role in apoptosis processes involved in cardiac myocyte death. The aim of current study was to explore the association of two genetic variants in ENDOG gene (ENDOG) with CVD risk factors in an Iranian population. METHODS: Subjects included 663 patients with CVD and 282 healthy individuals recruited as part of the Mashhad Stroke and Heart Atherosclerotic Disorders Cohort Study. The ENDOG S12L (rs 2293969) and L142M (rs 61397314) variants were genotyped. Anthropometric and biochemical factors were measured in all the subjects followed by univariate and multivariate analyses to determine the association of these genetic markers with CVD and biochemical parameters. RESULTS: ENDOG polymorphisms were found at a significantly higher prevalence in individuals who had histories of smoking and breaking point in L142M. In contrast, other risk factors for cardiovascular disease, including lipid profile and blood pressure, showed no or very weak relationship with the ENDOG polymorphisms. CONCLUSION: Our findings indicated an association between an ENDOG genetic variant and smoking history as a cardiovascular risk factor. Further studies in the prospective setting are warranted to investigate the value of this marker.

Association of nutritional status with socio-economic and demographic variables of under five year old Nepalese children.

Background: To see which socioeconomic and demographic variables associate with the nutritional status of under five-year old Nepalese children. This nationwide study provides a comprehensive analysis on of risk factors for childhood acute and chronic undernutrion. Methods: The Nepal Demographic and Health Survey 2006 was used as a cross sectional data source. A total of 3630 children were analysed. Standard Z-score were used for children. Anaemia was also defined using international norms. The statistical analysis used was binary logistic regression, which was performed using SPSS software package for Windows. The cut-off for a significant result was <0.05. Results: The results showed that 1680 (46.3%) of children were stunted, 1384 (38.1%) were underweight, 513 (14.1%) were wasted and 1631 (44.9%) were anaemic. Underweight and stunting showed significant association with mother's education and ethnicity. All nutritional factors were associated with ecological zone and standard of living. Also, underweight and wasting showed a significant relationship with religion. Conclusion: Maternal education, ecological zone, ethnicity and standard of living were the main predictors of child nutritional status.

A Dermal Equivalent Engineered with TGF-ß3 Expressing Bone Marrow Stromal Cells and Amniotic Membrane: Cosmetic Healing of Full-Thickness Skin Wounds in Rats.

Transforming growth factor beta-3 (TGF-ß3) has been shown to decrease scar formation after scheduled topical applications to the cutaneous wounds. This study aimed to continuously deliver TGF-ß3, during the early phase of wound healing, by engineering a dermal equivalent (DE) using TGF-ß3 expressing bone marrow stromal cells (BM-SCs) and human dehydrated amniotic membrane (hDAM). To engineer a DE, rat BM-SCs were seeded on the hDAM and TGF-ß3 was transiently transfected into the BM-SCs using a plasmid vector. Pieces of the dermal equivalent were transplanted onto the full-thickness excisional skin wounds in rats. The process of wound healing was assessed by image analysis, Manchester Scar Scale (MSS), and histopathological studies 7, 14, 21, and 85 days after the excision. The results confirmed accurate construction of recombinant pcDNA3.1-TGF-ß3 expression system and showed that the transfected BM-SCs seeded on hDAM expressed TGF-ß3 mRNA and protein from day 3 through day 7 after transfection. After implantation of the DE, contraction of the wounds was measured from day 7 through 21 and analyzed by linear regression, which revealed that the rate of wound contraction in all experimental groups was similar. Histologic evaluation demonstrated that transfected BM-SCs decreased retention and recruitment of the cells during the early stage of wound healing, decreased the formation of vascular structures and led to formation of uniformly parallel collagen bundles. MSS scores showed that TGF-ß3 secreting cells significantly improved the cosmetic appearance of the healed skin and decreased the scar formation. From these results, it could be concluded that transient secretion of TGF-ß3, during the early phase of healing, by BM-SCs seeded on hDAM can improve the cosmetic appearance of the scar in cutaneous wounds without negatively affecting the process of wound repair.

Characterization of Lung Fibroblasts More than Two Decades after Mustard Gas Exposure.

PURPOSE: In patients with short-term exposure to the sulfur mustard gas, the delayed cellular effects on lungs have not been well understood yet. The lung pathology shows a dominant feature consistent with obliterative bronchiolitis, in which fibroblasts play a central role. This study aims to characterize alterations to lung fibroblasts, at the cellular level, in patients with delayed respiratory complications after short-term exposure to the sulfur mustard gas. METHODS: Fibroblasts were isolated from the transbronchial biopsies of patients with documented history of exposure to single high-dose sulfur mustard during 1985-7 and compared with the fibroblasts of control subjects. RESULTS: Compared with controls, patients' fibroblasts were thinner and shorter, and showed a higher population doubling level, migration capacity and number of filopodia. Sulfur mustard decreased the in vitro viability of fibroblasts and increased their sensitivity to induction of apoptosis, but did not change the rate of spontaneous apoptosis. In addition, higher expression of alpha smooth muscle actin showed that the lung's microenvironment in these patients is permissive for myofibroblastic differentiation. CONCLUSIONS: These findings suggest that in patients under the study, the delayed pulmonary complications of sulfur mustard should be considered as a unique pathology, which might need a specific management by manipulation of cellular components.

The effect of intrathecal delivery of bone marrow stromal cells on hippocampal neurons in rat model of Alzheimer's disease.

OBJECTIVES: Intracerebral injection of bone marrow stromal cells (BMSCs) is being investigated as a therapeutic tool to prevent Alzheimer's disease (AD). Our aim was to investigate the effects of BMSCs by intrathecal injection in AD rat model. MATERIALS AND METHODS: BMSCs were obtained from the bone marrow of Wistar rat and transplanted into AD rat model via intrathecal injection. The rat model had received an injection of ß amyloid into the hippocampus for histological and immunohistochemical studies. RESULTS: Histological examination of the brains in transplanted rats compared to controls demonstrated the migration of BrdU-labeled BMSCs from the site of delivery, confirmed the differentiation of BMSCs transplanted cells into the cholinergic neurons, and increased number of healthy and decreased number of dark neurons. CONCLUSION: Our results showed that BMSCs intratechal administration could be a promising method for treatment of Alzheimer's disease in rat model.