Mesenchymal Stem Cell Responses to Bone-Mimetic Electrospun Matrices Composed of Polycaprolactone, Collagen I and Nanoparticulate Hydroxyapatite

The performance of biomaterials designed for bone repair depends, in part, on the ability of the material to support the adhesion and survival of mesenchymal stem cells (MSCs). In this study, a nanofibrous bone-mimicking scaffold was electrospun from a mixture of polycaprolactone (PCL), collagen I, and hydroxyapatite (HA) nanoparticles with a dry weight ratio of 50/30/20 respectively (PCL/col/HA). The cytocompatibility of this tri-component scaffold was compared with three other scaffold formulations: 100% PCL (PCL), 100% collagen I (col), and a bi-component scaffold containing 80% PCL/20% HA (PCL/HA). Scanning electron microscopy, fluorescent live cell imaging, and MTS assays showed that MSCs adhered to the PCL, PCL/HA and PCL/col/HA scaffolds, however more rapid cell spreading and significantly greater cell proliferation was observed for MSCs on the tri-component bone-mimetic scaffolds. In contrast, the col scaffolds did not support cell spreading or survival, possibly due to the low tensile modulus of this material. PCL/col/HA scaffolds adsorbed a substantially greater quantity of the adhesive proteins, fibronectin and vitronectin, than PCL or PCL/HA following in vitro exposure to serum, or placement into rat tibiae, which may have contributed to the favorable cell responses to the tri-component substrates. In addition, cells seeded onto PCL/col/HA scaffolds showed markedly increased levels of phosphorylated FAK, a marker of integrin activation and a signaling molecule known to be important for directing cell survival and osteoblastic differentiation. Collectively these results suggest that electrospun bone-mimetic matrices serve as promising degradable substrates for bone regenerative applications

Sometimes they used to whisper in our ears: Health care workers perceptions of the effects of abortion legalization in Nepal

Background: Unsafe abortion has been a significant cause of maternal morbidity and mortality in Nepal. Since legalization in 2002, more than 1,200 providers have been trained and 487 sites have been certified for the provision of safe abortion services. L

Effects of a monthly injectable steroidal contraceptive, Mesigyna, on menstrual pattern, lipoproteins, and coagulation parameters

WOS: 000168767700007PubMed: 11368988The objective of this study was to determine the effects of a once-monthly injectable contraceptive (Mesigyna) on menstrual pattern, lipoproteins, and coagulation parameters. Thirty-six women aged 18-35 years requesting monthly injectable contraception were included. Before injecting estradiol valerate 5 mg and norethisterone enanthate 50 mg, coagulation, lipoprotein, and liver function parameters were determined. After the 3- and 6-month injections, the same coagulation and serum lipid measurements and liver function tests were repeated, and women were questioned about their menstrual patterns and side effects. Thirty women who completed 6 months were evaluated. At the end of 3 months, two-thirds of the 30 women had normal menstrual patterns; at the end of 6 months, 80% of the women had normal menses. Serum LDL, total cholesterol, and triglyceride levels did not change significantly, while HDL and VLDL decreased significantly (p = 0.032 and p = 0.039, respectively) at 6 months. PT and aPTT measures did not change at the end of 6 months, while fibrinogen levels were significantly lower (p = 0.013). Serum total bilirubin levels increased (p = 0.022) and albumin levels decreased (p = 0.022) at the end of 6 months. Mesigyna was well tolerated and side effects and menstrual abnormalities were acceptable. There were no clinically significant changes in lipoprotein, coagulation, or hepatic parameters. (C) 2001 Elsevier Science Inc. All rights reserved