Background: Number of joint infections caused by Vancomycin-resistant pathogens is emerging. Currently no PMMA cement is commercially available to cover VRE. Daptomycin shows promising results in infection treatment, offers a good safety profile and reduced risk for resistance development. Purpose of this in vitro study is to investigate the mechanical stability, handling properties, elution behavior and antimicrobial effectiveness of PMMA cement loaded with three different Daptomycin concentrations in comparison to commercially available ALBC; Methods: Mechanical properties and handling characteristics (ISO 5833, DIN 53435), HPLC elution, antimicrobial effectiveness with proliferation assay (DIN 17025) and inhibition zone testing were investigated; Results: All tested Daptomycin concentrations fulfilled ISO and DIN mechanical strength. Dosage of 0.5. g added Daptomycin did not show any antimicrobial effectiveness in contrast to 1.0 g and1.5 g. Cement with 1.5 g Daptomycin was best in elution and effectiveness, showed good mechanical ISO strength, ISO doughing was a little longer sticky and setting was faster as Vancomycin containing reference cement; Conclusion: PMMA cement containing 0.5 g Gentamicin and 1.5 g Daptomycin could be a good alternative to the already established COPAL® G+V for PJI treatment of VRE.

Pathogenesis of aortic aneurysm and dissection continues to be under discussion. Extracellular matrix (ECM) remodeling processes in the aortic wall are hypothesized to be involved in the development of the disorders. Therefore, in a histological study, we investigated the expression of metalloproteases 1 and 9 (MMP1 and MMP9) and their inhibitors (TIMP 1 and TIMP 2) in cardiac surgery patients. In parallel, we studied the aortic roots by echocardiography. Clinical reports of 111 patients (30 women and 81 men) who suffered from aortic aneurysms and an aortic dissection were evaluated and studied by transesophageal echocardiography. Seven patients, who had coronary heart disease served as „healthy controls“ All patients were surgically operated in the period from 2007 to 2015. A tissue sample of the aortic biopsies was collected from each patient during surgery. Immunohistochemical staining was performed for MMP1, MMP9 and TIMP1, TIMP2 as well. Vascularization was monitored by an CD 31 antibody. In direct comparison, the expressions are not homogeneous. We found smallest changes in the intima area at all. An increase in MMP 1 and MMP 9 expression was detected in both media and adventitia in case of dissections. TIMP 1 and TIMP 2 distribution increases from the lumen of the vessel outward in the wall layers of the aorta. In case of arteriosclerotic changes, intima had a capillarization, but not in the media. Opposite pattern was found in the dissected aortas. Whereas the intima appears empty, vascularization was found in the media and adventitia layers, as well. There are differences in the vascularization between between the aneurysm and dissection and the different layers as well, respectively. A different remodeling process of the ECM in comparison of the vascular layers must be hypothesized. Reading the patterns of staining and with regard to the known inhibitory effect of MMP9 on ECM remodeling, but especially TIMP 2 on neoangiogenesis, a disturbed nutrition and a dysfunctional vasa vasorum remodeling must be assumed as cause of dissection.