Xeno-Free In Vitro Cultivation and Osteogenic Differentiation of hAD-MSCs on Resorbable 3D Printed RESOMER®.

The development of alloplastic resorbable materials can revolutionize the field of implantation technology in regenerative medicine. Additional opportunities to colonize the three-dimensionally (3D) printed constructs with the patient's own cells prior to implantation can improve the regeneration process but requires optimization of cultivation protocols. Human platelet lysate (hPL) has already proven to be a suitable replacement for fetal calf serum (FCS) in 2D and 3D cell cultures. In this study, we investigated the in vitro biocompatibility of the printed RESOMER® Filament LG D1.75 materials as well as the osteogenic differentiation of human mesenchymal stem cells (hMSCs) cultivated on 3D printed constructs under the influence of different medium supplements (FCS, human serum (HS) and hPL). Additionally, the in vitro degradation of the material was studied over six months. We demonstrated that LG D1.75 is biocompatible and has no in vitro cytotoxic effects on hMSCs. Furthermore, hMSCs grown on the constructs could be differentiated into osteoblasts, especially supported by supplementation with hPL. Over six months under physiological in vitro conditions, a distinct degradation was observed, which, however, had no influence on the biocompatibility of the material. Thus, the overall suitability of the material LG D1.75 to produce 3D printed, resorbable bone implants and the promising use of hPL in the xeno-free cultivation of human MSCs on such implants for autologous transplantation have been demonstrated.

Vacuum arc plasma deposition of thin titanium dioxide films on silicone elastomer as a functional coating for medical applications.

Silicone elastomer is a promising material for medical applications and is widely used for implants with blood and tissue contact. However, its strong hydrophobicity limits adhesion of tissue cells to silicone surfaces, which can impair the healing process. To improve the biological properties of silicone, a triggerless pulsed vacuum cathodic arc plasma deposition technique was applied to deposit titanium dioxide (TiO2) films onto the surface. Scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy and contact angle measurements were used for coating characterization. Deposited films were about 150nm thick and exhibited good adhesion to the underlying silicone substrate. Surface wettability and roughness both increased after deposition of the TiO2 layer. In addition, cell-biological investigations demonstrated that the in-vitro cytocompatibility of TiO2-coated samples was greatly improved without impacting silicone's nontoxicity. For validation of use in medical devices, further investigations were conducted and demonstrated stability of surface properties in an aqueous environment for a period of 68days and the coating's resistance to several sterilization methods.

A novel blood incubation system for the in-vitro assessment of interactions between platelets and biomaterial surfaces under dynamic flow conditions: The Hemocoater.

Hemocompatibility evaluation of biomaterials necessitates the use of blood incubation systems which simulate physiological flow conditions. However, most of the current systems have various limitations, especially restricted material variability, poor access to the test surface or damage of blood cells due to the use of a pump. In this paper, we combined the advantages of existent setups and developed a new planar shaped incubation test bench to lift those restrictions and mimic the pulsatile in-vivo situation. The adjustable flow conditions at the tested material surface were defined and corresponded to those in blood vessels. Platelet/material-interaction, as major aspect of hemocompatibility, was investigated for four common polymeric materials (polyoxymethylene, polypropylene, polyethylene and silicone elastomer) with platelet deprivation and platelet adhesion tests. Highly significant differences in the adhesion of platelets onto the tested material surfaces were measured. The number of adhered platelets on the most hydrophobic sample (silicone elastomer) was four-times higher than on the most hydrophilic sample (polyoxymethylene). These findings were confirmed with a scanning microscopic analysis and demonstrated the suitability of the testing device for the evaluation of platelet/material interactions. Moreover, hemolysis measurements demonstrated that the system did not provoke blood damage. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2430-2440, 2016.