@article{GoegeleMuellerBelovetal.2022, author = {G{\"o}gele, Clemens and M{\"u}ller, Silvana and Belov, Svetlana and Pradel, Andreas and Wiltzsch, Sven and Lenhart, Armin and Hornfeck, Markus and Kerling, Vera and R{\"u}bling, Achim and K{\"u}hl, Hannes and Sch{\"a}fer-Eckart, Kerstin and Minnich, Bernd and Weiger, Thomas Martin and Schulze-Tanzil, Gundula}, title = {Biodegradable Poly(D-L-lactide-co-glycolide) (PLGA)-Infiltrated Bioactive Glass (CAR12N) Scaffolds Maintain Mesenchymal Stem Cell Chondrogenesis for Cartilage Tissue Engineering}, series = {Cells}, volume = {11}, journal = {Cells}, number = {9}, publisher = {MDPI AG}, issn = {2073-4409}, doi = {10.3390/cells11091577}, pages = {30}, year = {2022}, abstract = {Regeneration of articular cartilage remains challenging. The aim of this study was to increase the stability of pure bioactive glass (BG) scaffolds by means of solvent phase polymer infiltration and to maintain cell adherence on the glass struts. Therefore, BG scaffolds either pure or enhanced with three different amounts of poly(D-L-lactide-co-glycolide) (PLGA) were characterized in detail. Scaffolds were seeded with primary porcine articular chondrocytes (pACs) and human mesenchymal stem cells (hMSCs) in a dynamic long-term culture (35 days). Light microscopy evaluations showed that PLGA was detectable in every region of the scaffold. Porosity was greater than 70\%. The biomechanical stability was increased by polymer infiltration. PLGA infiltration did not result in a decrease in viability of both cell types, but increased DNA and sulfated glycosaminoglycan (sGAG) contents of hMSCs-colonized scaffolds. Successful chondrogenesis of hMSC-colonized scaffolds was demonstrated by immunocytochemical staining of collagen type II, cartilage proteoglycans and the transcription factor SOX9. PLGA-infiltrated scaffolds showed a higher relative expression of cartilage related genes not only of pAC-, but also of hMSC-colonized scaffolds in comparison to the pure BG. Based on the novel data, our recommendation is BG scaffolds with single infiltrated PLGA for cartilage tissue engineering.}, language = {en} } @article{GoegeleWiltzschLenhartetal.2021, author = {G{\"o}gele, Clemens and Wiltzsch, Sven and Lenhart, Armin and Civilleri, Aurelio and Weiger, Thomas Martin and Sch{\"a}fer-Eckart, Kerstin and Minnich, Bernd and Forchheimer, Lukas and Hornfeck, Markus and Schulze-Tanzil, Gundula}, title = {Highly porous novel chondro-instructive bioactive glass scaffolds tailored for cartilage tissue engineering}, series = {Materials Science and Engineering: C}, volume = {130}, journal = {Materials Science and Engineering: C}, publisher = {Elsevier BV}, issn = {0928-4931}, doi = {10.1016/j.msec.2021.112421}, pages = {15}, year = {2021}, abstract = {Cartilage injuries remain challenging since the regenerative capacity of cartilage is extremely low. The aim was to design a novel type of bioactive glass (BG) scaffold with suitable topology that allows the formation of cartilage-specific extracellular matrix (ECM) after colonization with chondrogenic cells for cartilage repair. Highly porous scaffolds with interconnecting pores consisting of 100 \% BG were manufactured using a melting, milling, sintering and leaching technique. Scaffolds were colonized with porcine articular chondrocytes (pAC) and undifferentiated human mesenchymal stromal cells (hMSC) for up to 35 days. Scaffolds displayed high cytocompatibility with no major pH shift. Scanning electron microscopy revealed the intimate pAC-scaffold interaction with typical cell morphology. After 14 days MSCs formed cell clusters but still expressed cartilage markers. Both cell types showed aggrecan, SOX9 gene and protein expression, cartilage proteoglycan and sulfated glycosaminoglycan synthesis for the whole culture time. Despite type II collagen gene expression could not anymore be detected at day 35, protein synthesis was visualized for both cell types during the whole culturing period, increasing in pAC and declining after day 14 in hMSC cultures. The novel BG scaffold was stable, cytocompatible and cartilage-specific protein synthesis indicated maintenance of pAC's differentiated phenotype and chondro-instructive effects on hMSCs.}, language = {en} } @article{EitelGramlHoppeetal.2023, author = {Eitel, Dominik and Graml, Johanna and Hoppe, Julia and Kaliwoda, Melanie and Hornfeck, Markus and Helbig, Uta}, title = {Synthesis and Structure of Carbon-doped TiO2 by Carbothermal Treatment}, series = {Nano Select}, volume = {4}, journal = {Nano Select}, number = {7}, publisher = {Wiley}, issn = {2688-4011}, doi = {10.1002/nano.202300022}, pages = {454 -- 461}, year = {2023}, abstract = {Carbon modified titanium dioxide (TiO2) is a promising candidate for catalytic applications or fuel cells, where the modified oxide could replace currently used catalyst support materials. Carbothermally treated TiO2 was successfully prepared by annealing under acetylene/nitrogen gas flow in a rotary tube furnace. The carbon content in the TiO2 samples ranged from 5 to 14.5 wt.-\% as determined by thermogravimetric measurements. The powders showed suppression of the phase transition from anatase to rutile up to a treatment temperature of 825°C. Above 600°C rutile is the thermodynamically stable phase, therefore the suppression must be attributed to either carbon in the lattice or the reducing atmosphere in the furnace. Raman spectra revealed the characteristic G and D bands, indicating the formation of carbonaceous species in the samples. In addition, a shift of the anatase Eg(1) band was observed indicating a lattice disorder pointing toward carbon incorporation into the lattice. Diffuse reflectance spectra show sub band gap absorption together with a shift of the absorption edge. Depending on the extraction method of band gaps from spectra, the band gap values show a decrease or increase with increasing carbon content. Details of the evaluation and interpretation of the spectra are discussed.}, language = {en} }