Patrick Ziegler

Extremely low frequency pulsed electromagnetic fields cause antioxidative defense mechanisms in human osteoblasts via induction of •O 2 − and H 2 O 2

Recently, we identified a specific extremely low-frequency pulsed electromagnetic field (ELF-PEMF) that supports human osteoblast (hOBs) function in an ERK1/2-dependent manner, suggesting reactive oxygen species (ROS) being key regulators in this process. Thus, this study aimed at investigating how ELF-PEMF exposure can modulate hOBs function via ROS. Our results show that single exposure to ELF-PEMF induced ROS production in hOBs, without reducing intracellular glutathione. Repetitive exposure (>3) to ELF-PEMF however reduced ROS-levels, suggesting alterations in the cells antioxidative stress response. The main ROS induced by ELF-PEMF were •O2− and H2O2, therefore expression/activity of antioxidative enzymes related to these ROS were further investigated. ELF-PEMF exposure induced expression of GPX3, SOD2, CAT and GSR on mRNA, protein and enzyme activity level. Scavenging •O2− and H2O2 diminished the ELF-PEMF effect on hOBs function (AP activity and mineralization). Challenging the hOBs with low amounts of H2O2 on the other hand improved hOBs function. In summary, our data show that ELF-PEMF treatment favors differentiation of hOBs by producing non-toxic amounts of ROS, which induces antioxidative defense mechanisms in these cells. Thus, ELF-PEMF treatment might represent an interesting adjunct to conventional therapy supporting bone formation under oxidative stress conditions, e.g. during fracture healing.

Imaging Cell Viability on Non-transparent Scaffolds — Using the Example of a Novel Knitted Titanium Implant

Intervertebral disc degeneration and disc herniation is one of the major causes of lower back pain. Depletion of extracellular matrix, culminating in nucleus pulposus (NP) extrusion leads to intervertebral disc destruction. Currently available surgical treatments reduce the pain but do not restore the mechanical functionality of the spine. In order to preserve mechanical features of the spine, total disc or nucleus replacement thus became a wide interest. However, this arthroplasty era is still in an immature state, since none of the existing products have been clinically evaluated. This study intends to test the biocompatibility of a novel nucleus implant made of knitted titanium wires. Despite all mechanical advantages, the material has its limits for conventional optical analysis as the resulting implant is non-transparent. Here we present a strategy that describes in vitro visualization, tracking and viability testing of osteochondro-progenitor cells on the scaffold. This protocol can be used to visualize the efficiency of the cleaning protocol as well as to investigate the biocompatibility of these and other non-transparent scaffolds. Furthermore, this protocol can be used to show adherence pattern of cells as well as cell viability and proliferation rates on/in the scaffold. This in vitro biocompatibility testing assay provides a propitious tool to analyze cell-material interaction in non-transparent and opaque scaffolds.

Proximale Femurfraktur und Insuffizienzfrakturen im Alter

ZusammenfassungDie proximale Femurfraktur ist nach wie vor eine der häufigsten Frakturen des höheren Alters. Es steht eine Vielzahl an Implantaten mit guter Evidenz zur Versorgung zur Auswahl. Jedoch unterscheidet sich das Patientengut stark, und Abweichungen in der Versorgung vom Standardpatient sind regelmäßig erforderlich. Ziel ist u. a. eine stabile Versorgung mit früher Mobilisierbarkeit, guter Beweglichkeit, geringen Beschwerden und Reduktion der Risiken. Weiterhin sollte dem postoperativen Management große Aufmerksamkeit gewidmet werden, um Problematiken, wie z. B. Delir und erneute Sturzereignisse, zu vermeiden. Da viele Frakturen auf eine vorbestehende Osteoporose zurückzuführen sind, kommt einer erweiterten Diagnostik und Therapie ein besonderer Stellenwert zu. Unter vorbestehender Bisphosphonat-Therapie wurden gelegentlich subtrochantäre Frakturen beschrieben. Nach der aktuellen Literatur besteht jedoch aktuell kein wesentlich erhöhtes Frakturrisiko – selbst unter lang andauernder medikamentöser Therapie. Eine Reevaluation der Gesamtsituation und eine intensivierte Nachsorge werden jedoch empfohlen.AbstractProximal femoral fractures are still one of the most common fractures in elderly people. Many implants with good evidence are available to choose from but patients greatly differ and deviations from the standard patient procedure are regularly necessary. The key objectives are early mobilization, good range of motion, freedom from pain and risk reduction. Furthermore, high priority in postoperative care management should be given to a reduction of postoperative delirium and reoccurrence of falling events. As many fractures are related to the presence of osteoporosis, further assessment and diagnostics are necessary. Bisphosphonates are approved medications in the treatment of osteoporosis but in recent years reports and studies could occasionally be found involving subtrochanteric femoral fractures under bisphosphonate treatment. According to recent references there is no evidence for an increased risk fracture, even during long-term treatment with these medications. Re-evaluation of the patient situation after years of treatment and intensive aftercare is recommended.