Nanomechanical assessment of human and murine collagen fibrils via atomic force microscopy cantilever-based nanoindentation

The nanomechanical assessment of collagen fibrils via atomic force microscopy (AFM) is of increasing interest within the biomedical research community. In contrast to conventional nanoindentation there exists no common standard for conducting experiments and analysis of data. Currently used analysis approaches vary between studies and validation of quantitative results is usually not performed, which makes comparison of data from different studies difficult. Also there are no recommendations with regards to the maximum indentation depth that should not be exceeded to avoid substrate effects. Here we present a methodology and analysis approach for AFM cantilever-based nanoindentation experiments that allows efficient use of captured data and relying on a reference sample for determination of tip shape. Further we show experimental evidence that maximum indentation depth on collagen fibrils should be lower than 10-15% of the height of the fibril to avoid substrate effects and we show comparisons between our and other approaches used in previous works. While our analysis approach yields similar values for indentation modulus compared to the Oliver-Pharr method we found that Hertzian analysis yielded significantly lower values. Applying our approach we successfully and efficiently indented collagen fibrils from human bronchi, which were about 30. nm in size, considerably smaller compared to collagen fibrils obtained from murine tail-tendon. In addition, derived mechanical parameters of collagen fibrils are in agreement with data previously published. To establish a quantitative validation we compared indentation results from conventional and AFM cantilever-based nanoindentation on polymeric samples with known mechanical properties. Importantly we can show that our approach yields similar results when compared to conventional nanoindentation on polymer samples. Introducing an approach that is reliable, efficient and taking into account the AFM tip shape, we anticipate that the present work may act as a guideline for conducting AFM cantilever-based nanoindentation of collagen fibrils. This may aid understanding of collagen-related diseases such as asthma, lung fibrosis or bone disease with potential alterations of collagen fibril mechanics. ?? 2014

Right Place, Right Time: Preferences of Women with Ovarian Cancer for Delivery of CAM Education

The purpose of this pilot study was to assess the feasibility of on-site complementary and alternative medicine (CAM) education sessions to maximize quality of life for women with ovarian cancer. The pilot intervention consisted of four weekly sessions, each focusing the techniques and benefits of a particular CAM topic (e.g., nutrition, massage, relaxation). Participants were recruited from the Center for Women’s Oncology at H. Lee Moffitt Cancer Center from 2010 to 2012. Eligible participants had an ovarian cancer diagnosis with a life expectancy of at least 12 months, and were 18 years or older. The Gynecologic Oncology research nurse invited women in the outpatient clinic who matched the eligibility criteria. The research nurse explained the study and provided an informed consent form and return envelope. Because ovarian cancer is not only a rare cancer but, also, most patients seen at Moffitt have recurrent or advanced disease, many women did not have an adequate ECOG score. Many women who consented had rapid changes in health status, with morbidity and mortality outpacing recruitment of the 20 needed to proceed with the four education sessions. Baseline and follow-up surveys were conducted to assess changes in QOL, knowledge, and satisfaction with the intervention. While 27 women consented and 24 women completed the baseline survey, only five women participated in the intervention. The five women who participated were all white, and at time of consenting had a mean age of 60 (SD 9.08) and an average of 102 months (SD 120.65) since diagnosis, and were all on active treatment, except for one. The intervention pilot did not encounter difficulties with regard to recruitment, but suffered problems in achieving an adequate number of women to launch the on-site sessions because of rapidly changing morbidity and significant mortality. The team recognized that a larger-scaled intervention comprised of on-site sessions was impractical and compared attendance rates with a more convenient format currently underway in the Women’s Oncology program at Moffitt. While low participation prevented an intervention analysis of scientific merit, the study data is informative with regard to barriers, facilitators, and alternative methods for sharing useful information to women with advanced ovarian cancer. The comparison strongly suggested that CAM education for women compromised by the disease and treatment associated with ovarian cancer would best be delivered in the convenient-access format that allowed remote access to live and recorded discussions of specific topics

Erratum to: Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition) (Autophagy, 12, 1, 1-222, 10.1080/15548627.2015.1100356

non present