Durante mucho tiempo no había principios uniformes para la Atribución de nombres a los antibióticos https://antibioticos-wiki.es . Más a menudo se les llama por el nombre genérico o especie del producto, con menos frecuencia-de acuerdo con la estructura química. Algunos antibióticos se nombran de acuerdo con el lugar donde se asignó el producto.
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Institut für Technische Chemie Partner in der Forschung der Universität Hannover Institut für Technische Chemie, Callinstr. 3, 30167 Hannover Application of a new rotating bed reactor system for cultivating 3D bone constructs Kirstin Suck1, Larissa Behr1, Martijn van Griensven2, Hans Hoffmeister3, Thomas Scheper1, 1Institut für Technische Chemie der Universität Hannover, Callinstr. 3, 30167 Hannover, GermanyBoltzmann Institut für experimentelle und klinische Traumatologie, Donaueschingenstr. 13, 1200 Wien, Austriaerk GmbH, Ziegeleistr. 7, 16727 Eichstädt, GermanyAbstract
Aim of the project is the development and testing of a rotating-bed bioreactor for the generationof bone tissue. Large bone defects caused by tumors, infectious diseases or trauma result in a
medical need for bone regeneration. The principle of bone tissue engineering is to seedosteoblasts, precursor or stem cells onto an appropriate 3D matrix and to cultivate the cell exhaust air
seeded scaffold in vitro in a suitabel biorector system. The generated tissue can be
implantated into the defect of the patient.
During the differentiation of bone tissue different osteoblastic markers (e.g alkalinephosphatase AP) are expressed. Finally, the cells are embedded in the extracellular matrix and sparging
begin to mineralise by depositing mineral along and within collagen fibrils. The suitability of twodifferent 3D macroporous scaffolds (Sponceram® and Sponceram
bone tissue was investigated under static and dynamic conditions. Sponceram® scaffolds Material and Methods Scaffolds: Macroporous ceramic Sponceram® Cell seeding: Scaffolds were incubated for 24 h in medium at 37°C, 5 % Co . Either primary
osteoblasts or MC3T3-E1 cells were seeded on each scaffold in 96-well plates for 30 min at
Standard medium: DMEM, 10 % FCS, antibiotics Differentiation medium: Standard medium + 1 µM dexamethasone, 10 mM b-glycerol- Differentiation medium + BMP-2 (10 ng/ml) Cell viability was assayed using MTT-test. Alkaline phosphatase (AP) was determined by an assay based on the hydrolysis of p- nitrophenyl phosphate to p-nitrophenol. Pre-screening Bioreactor cultivation (static condition) (dynamic conditions)
Samples of Sponceram® of approximately 3 mm x
The BIOSTAT® B plus RBS 500 was designed as a
3 mm x 4 mm were preconditioned for 24 h in cell
multi-purpose high density cell culturing device for
culture medium at 37°C, 5 % CO . Subsequently,
anchorage-dependent cell lines and primary cells.
1.5 x 10 MC3T3-E1 cells in 80 µl medium were
In this study the bioreactor was equipped with 4
seeded on each scaffold in 96-well dishes for 30 min
Sponceram® carrier discs for each cultivation. Cell
at gentle stirring at 37°C, 5 % CO . Non attached
inoculation was carried out with a total volume of 2 ml
cells were removed and the wells were filled up with
cell suspension/disc with a cell density of 1 1
200 µl medium. The cultivations were performed for
disc. To allow adhesion onto the Sponceram® surface
the reactor was filled with 300 ml of differentiation
The cells were cultivated in three different media:
medium 30 min after cell inoculation. The bioreactor
standard medium, differentiation medium and
features a unique technology for improved oxygen and
differentiation medium containing BMP-2. The
nutrient supply through the alternating exposure to
effect of the media composition on cell viability and
medium and gas phase. The cultivation was performed
the differentiation process was investigated and
at 37°C, 2 rpm and a pH of 7.3 for 25 days. MC3T3-E1 Primary Osteoblasts
Results for the cell viability (MTT-test) of MC3T3-E1 cells
During the bioreactor cultivation the cell growth of the
cultured on Sponceram in standard medium, differentiation
osteobalsts was monitored by the determination of glucose
medium and BMP-2 medium show a high cell viability during
consumption using the YSI 2700 (Yellow Springs
the first ten days. The cell viabilty attained a plateau phase
Instruments, USA). Cells were cultivated on Sponceram
followed by a decrease after 10 days due to high confluence
and Sponceram /HA using differentiation medium. Total
glucose consumption after 25 days: 14.05 g.
Glucose consumption during the bioreactor cultivation
The differentiation process of the preosteoblastic
The mineralisation of the extracellular matrix
determination of the early osteogenic marker alkaline
phosphatase (AP). The highest enzyme activity was
Kossa. In each picture scaffolds are shown
achieved at day 5 in BMP-2 medium due to the
after bioreactor cultivation for 25 days (right)
differentiation induction of the growth factor.
in comparison to the control matrix (left). The
Scanning electron micrographs (SEM) show the cell morphology
After bioreactor cultivation of the primary
of MC3T3-E1 cells cultured on Sponceram .
osteoblasts a dense layer of cells and parallel
under static conditions in 96-well dishes display that the cells grew
structures of ECM fibrils can be observed in
well inside the macroporous structure of Sponceram® showing a
the SEM pictures. The ceramic material is no
cuboid morphology of osteoblasts-like cells. Cells were cultured
longer visible. Moreover, the formation of
for 10 days. They grew as a network having intercellular contacts
Conclusion
In summary, this study demonstrated that the newly developed ceramic material Sponceram® is an appropiate scaffold for the cultivation of MC3T3-E1 cells. The macroporous structure ofthe scaffold contributed to a fast cell attachment and proliferation. The ultimate shape of the 3D structure supports the differentiation process of preosteoblastic cells even in the absenceof BMP-2. The rotating-bed bioreactor BIOSTAT® Bplus RBS features a unique technology for improved oxygen and nutrient supply for the cells through the alternating exposure tomedium and gas phase. Therefore, the BIOSTAT® Bplus RBS equipped with Sponceram® discs provides an optimal environment for bone tissue generation. Primary osteoblasts weresuccessfully cultivated on Sponceram® and Sponceram /HA
for 25 days in the bioractor system. The analyses revealed a bone tissue-like generation of a fibril structured mineralised
Acknowledgement
The authors like to thank Dr. A. Feldhoff and F. Steinbach (University of Hannover) for the SEM pictures und Prof. W. Sebald for kindly donating BMP-2.
SECURITIES AND EXCHANGE COMMISSION OF PAKISTAN S.R.O. 471(I)/2003. – In exercise of the powers conferred by section 41 of the Modaraba Companies and Modaraba (Floatation and Control) Ordinance, 1980 (XXXI of 1980), read with clause (b) of section 43 of the Securities and Exchange Commission of Pakistan Act, 1997 (XLII of 1997) and the Finance Division’s Notification No. S.R.O. 698(I)/86,
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