TY  - JOUR
A1  - Ramírez-Rodríguez, Gloria Belén
A1  - Pereira, Ana Rita
A1  - Herrmann, Marietta
A1  - Hansmann, Jan
A1  - Delgado-López, José Manuel
A1  - Sprio, Simone
A1  - Tampieri, Anna
A1  - Sandri, Monica
T1  - Biomimetic mineralization promotes viability and differentiation of human mesenchymal stem cells in a perfusion bioreactor
JF  - International Journal of Molecular Sciences
N2  - In bone tissue engineering, the design of 3D systems capable of recreating composition, architecture and micromechanical environment of the native extracellular matrix (ECM) is still a challenge. While perfusion bioreactors have been proposed as potential tool to apply biomechanical stimuli, its use has been limited to a low number of biomaterials. In this work, we propose the culture of human mesenchymal stem cells (hMSC) in biomimetic mineralized recombinant collagen scaffolds with a perfusion bioreactor to simultaneously provide biochemical and biophysical cues guiding stem cell fate. The scaffolds were fabricated by mineralization of recombinant collagen in the presence of magnesium (RCP.MgAp). The organic matrix was homogeneously mineralized with apatite nanocrystals, similar in composition to those found in bone. X-Ray microtomography images revealed isotropic porous structure with optimum porosity for cell ingrowth. In fact, an optimal cell repopulation through the entire scaffolds was obtained after 1 day of dynamic seeding in the bioreactor. Remarkably, RCP.MgAp scaffolds exhibited higher cell viability and a clear trend of up-regulation of osteogenic genes than control (non-mineralized) scaffolds. Results demonstrate the potential of the combination of biomimetic mineralization of recombinant collagen in presence of magnesium and dynamic culture of hMSC as a promising strategy to closely mimic bone ECM.
KW  - scaffold
KW  - perfusion bioreactor
KW  - collagen
KW  - apatite nanoparticles
KW  - magnesium
KW  - human mesenchymal stem cell
KW  - osteogenesis
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-285804
SN  - 1422-0067
VL  - 22
IS  - 3
ER  - 
TY  - JOUR
A1  - Kowalewicz, Katharina
A1  - Vorndran, Elke
A1  - Feichtner, Franziska
A1  - Waselau, Anja-Christina
A1  - Brueckner, Manuel
A1  - Meyer-Lindenberg, Andrea
T1  - In-vivo degradation behavior and osseointegration of 3D powder-printed calcium magnesium phosphate cement scaffolds
JF  - Materials
N2  - Calcium magnesium phosphate cements (CMPCs) are promising bone substitutes and experience great interest in research. Therefore, in-vivo degradation behavior, osseointegration and biocompatibility of three-dimensional (3D) powder-printed CMPC scaffolds were investigated in the present study. The materials Mg225 (Ca\(_{0.75}\)Mg\(_{2.25}\)(PO\(_4\))\(_2\)) and Mg225d (Mg225 treated with diammonium hydrogen phosphate (DAHP)) were implanted as cylindrical scaffolds (h = 5 mm, Ø = 3.8 mm) in both lateral femoral condyles in rabbits and compared with tricalcium phosphate (TCP). Treatment with DAHP results in the precipitation of struvite, thus reducing pore size and overall porosity and increasing pressure stability. Over 6 weeks, the scaffolds were evaluated clinically, radiologically, with Micro-Computed Tomography (µCT) and histological examinations. All scaffolds showed excellent biocompatibility. X-ray and in-vivo µCT examinations showed a volume decrease and increasing osseointegration over time. Structure loss and volume decrease were most evident in Mg225. Histologically, all scaffolds degraded centripetally and were completely traversed by new bone, in which the remaining scaffold material was embedded. While after 6 weeks, Mg225d and TCP were still visible as a network, only individual particles of Mg225 were present. Based on these results, Mg225 and Mg225d appear to be promising bone substitutes for various loading situations that should be investigated further.
KW  - farringtonite
KW  - stanfieldite
KW  - 3D powder printing
KW  - scaffold
KW  - biocompatibility
KW  - degradable bone substitutes
KW  - osseointegration
KW  - in-vivo Micro-Computed Tomography
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228929
SN  - 1996-1944
VL  - 14
IS  - 4
ER  -