TY  - JOUR
A1  - Stuckensen, Kai
A1  - Lamo-Espinosa, José M.
A1  - Muiños-López, Emma
A1  - Ripalda-Cemboráin, Purificación
A1  - López-Martínez, Tania
A1  - Iglesias, Elena
A1  - Abizanda, Gloria
A1  - Andreu, Ion
A1  - Flandes-Iparraguirre, María
A1  - Pons-Villanueva, Juan
A1  - Elizalde, Reyes
A1  - Nickel, Joachim
A1  - Ewald, Andrea
A1  - Gbureck, Uwe
A1  - Prósper, Felipe
A1  - Groll, Jürgen
A1  - Granero-Moltó, Froilán
T1  - Anisotropic cryostructured collagen scaffolds for efficient delivery of RhBMP−2 and enhanced bone regeneration
JF  - Materials
N2  - In the treatment of bone non-unions, an alternative to bone autografts is the use of bone morphogenetic proteins (BMPs), e.g., BMP–2, BMP–7, with powerful osteoinductive and osteogenic properties. In clinical settings, these osteogenic factors are applied using absorbable collagen sponges for local controlled delivery. Major side effects of this strategy are derived from the supraphysiological doses of BMPs needed, which may induce ectopic bone formation, chronic inflammation, and excessive bone resorption. In order to increase the efficiency of the delivered BMPs, we designed cryostructured collagen scaffolds functionalized with hydroxyapatite, mimicking the structure of cortical bone (aligned porosity, anisotropic) or trabecular bone (random distributed porosity, isotropic). We hypothesize that an anisotropic structure would enhance the osteoconductive properties of the scaffolds by increasing the regenerative performance of the provided rhBMP–2. In vitro, both scaffolds presented similar mechanical properties, rhBMP–2 retention and delivery capacity, as well as scaffold degradation time. In vivo, anisotropic scaffolds demonstrated better bone regeneration capabilities in a rat femoral critical-size defect model by increasing the defect bridging. In conclusion, anisotropic cryostructured collagen scaffolds improve bone regeneration by increasing the efficiency of rhBMP–2 mediated bone healing.
KW  - rhBMP–2
KW  - collagen sponge
KW  - cryostructured scaffolds
KW  - bone critical size defect
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-195966
SN  - 1996-1944
VL  - 12
IS  - 19
ER  - 
TY  - JOUR
A1  - Schmitz, Tobias
A1  - Jannasch, Maren
A1  - Weigel, Tobias
A1  - Moseke, Claus
A1  - Gbureck, Uwe
A1  - Groll, Jürgen
A1  - Walles, Heike
A1  - Hansmann, Jan
T1  - Nanotopographical Coatings Induce an Early Phenotype-Specific Response of Primary Material-Resident M1 and M2 Macrophages
JF  - Materials
N2  - Implants elicit an immunological response after implantation that results in the worst case in a complete implant rejection. This biomaterial-induced inflammation is modulated by macrophages and can be influenced by nanotopographical surface structures such as titania nanotubes or fractal titanium nitride (TiN) surfaces. However, their specific impact on a distinct macrophage phenotype has not been identified. By using two different levels of nanostructures and smooth samples as controls, the influence of tubular TiO2 and fractal TiN nanostructures on primary human macrophages with M1 or M2-phenotype was investigated. Therefore, nanotopographical coatings were either, directly generated by physical vapor deposition (PVD) or by electrochemical anodization of titanium PVD coatings. The cellular response of macrophages was quantitatively assessed to demonstrate a difference in biocompatibility of nanotubes in respect to human M1 and M2-macrophages. Depending on the tube diameter of the nanotubular surfaces, low cell numbers and impaired cellular activity, was detected for M2-macrophages, whereas the impact of nanotubes on M1-polarized macrophages was negligible. Importantly, we could confirm this phenotypic response on the fractal TiN surfaces. The results indicate that the investigated topographies specifically impact the macrophage M2-subtype that modulates the formation of the fibrotic capsule and the long-term response to an implant.
KW  - nanotopographical surfaces
KW  - combination of physical vapor deposition and electrochemical etching
KW  - defined humanized test system
KW  - inflammatory response
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-203378
SN  - 1996-1944
VL  - 13
IS  - 5
ER  -