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Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_16 | Pages 40 - 40
1 Nov 2018
Berkmann JC Qazi TH Hafeez S Schmidt J Schoon J Geissler S Duda GN Boccaccini AR Lippens E
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Promising work on bioactive glasses (BAGs) in bone defect regeneration has led to their clinical implementation. However, the effects of the ionic dissolution products of different types and the physical interaction modalities of BAGs on the behavior and function of mesenchymal stromal cells (MSCs) of human patients have not received sufficient attention. Recently, we showed that the in vitro response of hMSC to micron-sized, monodispersed BAGs is dependent on dosage, composition, and mode of interaction1. Two commercially available and widely used types of BAGs, namely the silicate BAGs 45S5 and 1393, were used to study hMSC cell behavior. Interestingly, exposure to 1393 BAG resulted in superior metabolic activity, proliferation, and cell spreading compared to 45S5 BAG in similar dosage, suggesting that additional cellular functions could also be differentially modulated by both glasses1. In the context of bone regeneration, the hMSCs’ potential to secrete angiogenic factors as well as deposit mineralized matrix upon exposure to BAG dissolution products was investigated in the present study. Aside from dose-dependent effects of both glasses, 45S5 BAG induced a significant pro-angiogenic response, demonstrated by robust tube formation in HUVECs in the presence of MSC conditioned media. 1393 BAG, on the other hand, stimulated osteogenesis by upregulating osteogenic gene expression and mineralized matrix deposition. Based on these results, combining the pro-angiogenic 45S5 BAG and the pro-osteogenic 1393 BAG might be an attractive strategy to target the multiple processes underlying bone regeneration. These results highlight how different BAGs can be utilized to promote MSC-mediated bone regeneration.


Bone & Joint Research
Vol. 7, Issue 1 | Pages 12 - 19
1 Jan 2018
Janz V Schoon J Morgenstern C Preininger B Reinke S Duda G Breitbach A Perka CF Geissler S

Objectives

The objective of this study was to develop a test for the rapid (within 25 minutes) intraoperative detection of bacteria from synovial fluid to diagnose periprosthetic joint infection (PJI).

Methods

The 16s rDNA test combines a polymerase chain reaction (PCR) for amplification of 16s rDNA with a lateral flow immunoassay in one fully automated system. The synovial fluid of 77 patients undergoing joint aspiration or primary or revision total hip or knee surgery was prospectively collected. The cohort was divided into a proof-of-principle cohort (n = 17) and a validation cohort (n = 60). Using the proof-of-principle cohort, an optimal cut-off for the discrimination between PJI and non-PJI samples was determined. PJI was defined as detection of the same bacterial species in a minimum of two microbiological samples, positive histology, and presence of a sinus tract or intra-articular pus.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_5 | Pages 102 - 102
1 Mar 2017
Rakow A Schoon J Dienelt A John T Textor M Duda G Perka C Schulze F Ode A
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INTRODUCTION

The uncertainty of the biological effects of wear and corrosion from Metal-on-metal (MoM) implants has initiated a debate on their safety and use. Generally, the release of wear particles from MoM hip implants can clinically manifest in aseptic osteolysis. In our study, the effect of MoM-wear particles and particle originated Co and Cr ions on mesenchymal stromal cells (MSCs) was investigated [1]. The lead hypotheses were that (1) dissociated Co and Cr, originated from MoM-wear particles, accumulate in the bone marrow and (2) apparently impair the osteogenic function of local MSCs. This impairment could be one element contributing to the manifestation of periprosthetic osteolyses.

METHODS

The study was approved by the local ethical committee (EA1/194/13); all donors gave written informed consent. Blood (B), Synovial fluid (SF) periprosthetic tissue (PT) and bone marrow (BM) were collected from patients with at least one osteolytic lesion, undergoing a revision of a MoM hip implant. Patients undergoing primary THA served as controls. Metal wear particles were isolated from PT by enzymatic digestion and their size and shape characterized by transmission electron microscopy (TEM). Local and systemic levels of Co and Cr were analyzed by graphite furnace atomic absorption spectroscopy. MoM-MSCs and control-MSCs were isolated from BM for in vitro assessment of their viability, proliferation, migration and multilineage differentiation. In addition, control-MSCs were in vitro exposed to Co and Cr ions and assessed for their viability, proliferation and osteogenic differentiation.