Multifunctional biomaterials from the sea: Assessing the effects of chitosan incorporation into collagen scaffolds on mechanical and biological functionality

Natural biomaterials such as collagen show promise in tissue engineering applications due to their inherent bioactivity. The main limitation of collagen is its low mechanical strength and somewhat unpredictable and rapid degradation rate; however, combining collagen with another material, such as chitosan, can reinforce the scaffold mechanically and may improve the rate of degradation. Additionally, the high cost and the risk of prion transmission associated with mammal-derived collagen has prompted research into alternative sources such as marine-origin collagen. In this context, the overall goal of this study was to determine if the incorporation of chitosan into collagen scaffolds could improve the mechanical and biological properties of the scaffold. In addition the study assessed if collagen, derived from salmon skin (marine), can provide an alternative to collagen derived from bovine tendon (mammal) for tissue engineering applications. Scaffold architecture and mechanical properties were assessed as well as their ability to support mesenchymal stem cell growth and differentiation. Overall, the addition of chitosan to bovine and salmon skin-derived collagen scaffolds improved the mechanical properties, increasing the compressive strength, swelling ratio and prolonged the degradation rate. Mesenchymal stem cell (MSC) attachment and proliferation was most improved on the bovine-derived collagen scaffold containing a 75:25 ratio of collagen:chitosan, and when MSC osteogenic and chondrogenic potential on the scaffold was assessed, a significant increase in calcium production (p < 0.001) and sulfated glycosaminoglycan (sGAG) production (p < 0.001) was observed respectively. Regardless of chitosan content, the bovine-derived collagen scaffolds out-performed the salmon skin-derived collagen scaffolds, displaying a larger pore size and higher percentage porosity, more regular architecture, higher compressive modulus, a greater capacity for water uptake and allowed for more MSC proliferation and differentiation. This versatile scaffold incorporating the marine biomaterial chitosan show great potential as appropriate platforms for promoting orthopaedic tissue repair while the use of salmon skin-derived collagen may be more suitable in the repair of soft tissues such as skin.This work was funded by Science Foundation Ireland (SFI) through the Research Frontiers Programme (Grant No. 11/RFP/ENM/3063) and by the European Regional Development Fund (ERDF) through INTERREG 2007-2013 Program (POCTEP project 0687_NOVOMAR_1_P). Bovine collagen materials were provided by Integra Life Sciences, Inc. through a Material Transfer Agreement. Salmon skins were kindly offered by Pingo Doce, Braga (Portugal)

Correlations between changes in hematological indices of mothers with preeclampsia and umbilical cord blood of newborns

Preeclampsia is a condition that might severely impact the health of mothers and their newborns. The aim of this investigation is to examine hematological parameters in mothers with preeclampsia and umbilical cord blood. Eighty preecalmptic mothers were recruited in the study. In addition, eighty normal pregnant mothers served as controls. Hematological parameters that include hemoglobin (Hb), red blood cell count (RBC), red cell distribution width (RDW), packed cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), white blood cell counts (WBC), platelet counts, mean platelet volume (MPV) and Platelet large cell ratio (PLCR) were examined. Results showed a strong association between preeclampsia and low birth weight, premature/cesarean delivery and proteinuria (P < 0.001). Hb and neutrophils were significantly lower (P < 0.01), whereas RDW, PCV, MCV, MCH, MCHC and lymphocytes were significantly higher than normal ones (P < 0.01). When cord blood of preeclamptic mothers were compared with that of normal ones, similar findings were observed. In addition, results showed significant and positive correlations between preeclamptic mothers and their newborn in Hb (r2 = 0.075, P < 0.05), PCV (r2 = 0.084, P < 0.01), MCV (r2 = 0.077, P < 0.05), MCHC (r2 = 0.115, P < 0.01), RBC (r2 = 0.086, P < 0.01) and retics (r2 = 0.306, P < 0.01). In conclusion, changes in several hematological parameters associated with preeclampsia were correlated in affected mothers and their newborns. Such biomarkers can be used to predict pregnancy outcomes in women with preeclampsia

Cervical cytopathological changes among women with vaginal discharge attending teaching hospital

Aims: To find cytology changes among women attending obstetrics and gynaecology clinic with complaints of vaginal discharges. Settings and Design: This descriptive hospital-based cytological study was conducted at the outpatient clinic of the obstetrics and gynaecology department. Materials and Methods: Two hundred women with complaints of vaginal discharge were selected. Their detailed histories were documented on a special request form. Pap smears were then obtained and sent for cytological examination to the cytopathology department. All low-grade squamous intraepithelial lesion (LSIL) cases were advised to follow-up with Pap smears in the next 6–12 months. Those with high-grade squamous intraepithelial lesion (HSIL) were further investigated by a cervical biopsy and managed accordingly. Statistical analysis used: The statistical analysis was performed using, the Statistical Package for Social Science (SPSS). Chi-square and cross-tabulation were used in this study. Results: The cytological examination of Pap smears showed no changes (i.e. negative findings) in 88 (44%) cases, while Candida species infection was the most prevalent, which was found in 67 (33.5%) of the cases. Bacterial vaginosis was found in 39 women (19.5%); 6 women (3%) were reported with dyskaryotic changes. Two cases were found to have LSIL and 4 women had HSIL. Conclusion: Infection is common among the illiterate group of women. Women with vaginal discharges should undergo screening tests for evaluation by cervical smear for the early detection of cervical precancer conditions. There is an urgent need to establish a screening program for cervical cancer in Sudan

Evaluation of the ability of collagen-glycosaminoglycan scaffolds with or without mesenchymal stem cells to heal bone defects in Wistar rats.

PURPOSE: The aim of this experiment was to examine the capacity of collagen-glycosaminoglycan scaffolds, with or without mesenchymal stem cells, to satisfactorily repair a 5-mm rat calvarial defect. METHODS: Fifty-five Wistar rats were used in the study. The defects were either left empty to serve as controls (n = 7) or filled with cell-free scaffolds (n = 11), cell-seeded scaffolds that were pre-cultured in standard culture medium (n = 13), cell-seeded scaffolds that were pre-cultured in osteoinductive factor-supplemented medium (n = 12) or particulate autogenous bone (n = 12). The animals were sacrificed at 12 weeks after surgery, and specimens were prepared for histomorphometric analysis. The linear bone healing and the bone area within the defect were measured. RESULTS: Comparable results were obtained using cell-free collagen-glycosaminoglycan scaffolds and autogenous bone both in terms of linear bone healing (P < 0.986) and area of new bone (P < 0.846). While the test groups showed significantly more bone formation compared to the empty defect control group, the linear bone healing and area of new bone within the defect were significantly lower in the cell-seeded scaffolds than in the cell-free scaffolds. The results have demonstrated that a cell-free collagen-glycosaminoglycan scaffold is capable of repairing a 5-mm rat calvarial defect as effectively as autogenous bone and that seeding the scaffold with pre-cultured mesenchymal stem cells prior to implantation offered no beneficial effect and resulted in incomplete healing of the defect. CONCLUSIONS: The results thus suggest that the scaffold has immense potential for tissue repair showing favorable osteoconductive properties, biocompatibility and degradability.</p

Silver Nanoparticle Production by Ruta graveolens and Testing Its Safety, Bioactivity, Immune Modulation, Anticancer, and Insecticidal Potentials

Ruta graveolens, a plant belonging to the family Rutaceae, is traditionally used as a medicinal plant and a flavoring agent in food. This work aimed to prepare silver nanoparticles (AgNPs) using the ethanol extract from R. graveolens leaves and test different biological activities as well as insecticidal potentials in the extract and extract prepared AgNPs. Dried and powdered R. graveolens leaves were subjected to extraction using ethanol, and this extract was used to synthesize AgNPs. AgNP synthesis was monitored by the change in color, UV spectrophotometry, and electron microscopy (scanning). Fourier transform infrared (FT-IR) spectroscopy was used to monitor the functional groups in the extracts. Immunological, physiological, anticancer, antibacterial, and insecticidal potentials of the extract and its prepared AgNPs were tested. Results showed the ability of the leaf extract to synthesize. SEM examination revealed a spherical shape of AgNPs with a size of 40–45 nm. The extract contained many functional groups as indicated by FT-IR. The extract alone inhibited the growth of normal rat splenic cells, while the extract containing AgNPs stimulated its growth. Extract alone stimulated HeLa cell proliferation and inhibited HepG2 growth, while both cell line growth was inhibited by the extract containing AgNPs. Both the extract and extract with AgNPs were safe on RBCs and did not cause any severe elevation in liver enzymes. The extract alone and with AgNPs showed insecticidal activity against Culex pipiens. Our findings suggest that the R. graveolens leaf extract, alone or with AgNPs, is biologically safe on animal cells and has antibacterial, insecticidal, and immunomodulation potentials