homepage

Internship


Interested in an internship at Xpand Biotechnology BV?

Xpand is always looking for enthusiastic students from the University or Universities of Applied Sciences (HLO). Contact us if you want to discuss the possibilities to do an internship on one of the following subjects (phone +31 30 229 7280).

 

Assignments

 

Bioreactor Technology Xpand Biotechnology is focused on stem cell expansion for clinical applications. An innovative automated, closed bioreactor system is being developed that can be placed on location (in the hospital) in which patient-own adult stem cells can be culture expanded in clinically required quantities (200 to 800 million cells). This adult stem cell expander is generic and will allow use of the cells for many different clinical applications, including myocardial and vascular regeneration.

Bioprocess Technology: A bioreactor for the expansion of adult stem cells requires monitoring of cell growth in-line (without sampling). This project will include the research to relate stem cell growth to e.g. oxygen consumption by the cells or cell specific glucose consumption. Moreover, a biomass sensor is developed and should be tested in combination with the anchorage dependent mesenchymal stem cells in a microcarrier-based cultivation. This research will include cell culture in T-flasks and bioreactors, bioprocess techniques and calculations.

 

Downstream processing: After the expansion process, cells and carriers need to be separated and cell suspension will be concentrated and stored in suitable medium for further applications. For this project, several separation and concentration methods will be tested and compared, based on functionality, cell viability and the implementation in the total bioreactor system used for the expansion of stem cells in the hospital. This research will include cell culture and stem cell differentiation techniques and technical aspects of the downstream processing itself.

 

Culture optimization: Currently, stem cells are expanded at Xpand Biotechnology BV in medium containing animal serum. For clinical use it is preferred to expand the cells without the use of serum. For this project serum substitutes will be tested and compared, regarding functionality (growth rate), stem cell viability and differentiation potential of the stem cells after expansion. Feasibility studies will be performed in the conventional tissue culture flasks (2D). After 2D experiments, the selected serum substitute will be tested in a microcarrier based 3D system. This research will include cell culture (both in T-flasks and bioreactors) and cell differentiation techniques.

 

Instructive Bone Grafts Xpand manufactures a unique range of Calcium Phosphate (CaP) ceramics which can be used as synthetic bone void fillers for orthopaedic and dental applications. The products are based on a unique surface structured scaffold that, in preclinical testing, has shown an extraordinary ability to attract stem cells after implantation. These products have 510k approval from the FDA (Food and Drug Administration) and CE approval by the KEMA, therefore this product can safely be used within clinics in the USA and Europe.

This project is focusing on bridging the gap between theory and practice in preparation of CaP ceramics. Our scaffold R&D department focuses on three different CaP ceramics: (1) Tri-Calcium Phosphate ceramics (TCP, fast degradable); (2) HydroxyApatite ceramics (HA, slow degradable); (3) Biphasic Calcium Phosphate ceramics (BCP, a combination of HA and TCP, degradation rate dependable on the HA / TCP ratio). Theoretically by manipulating the Ca/P ratios of the starting chemicals, either TCP or HA or combinations thereof can be produced. However in practice the target CaP ceramics is not easily to achieve as the purity of the starting chemicals vary and the underlying chemical reaction rates are sometimes unclear. As the biological properties of these CaP ceramics vary with their microstructure and chemistry, it is very important to optimize the reproducibility of the manufacturing process. The following items are taken into consideration:

  • Develop reliable method(s) to determine the purities of the starting chemicals (calcium hydroxide and phosphoric acid), with following technologies: Vitros Analyzer, Titration, Calcium-ion specific electrode, or other tests if necessary;

  • Influences of Ca/P ratios on the chemistry of CaP ceramics, with the use of X-ray Diffraction Method (XRD) using the quantitative Rietveld method, Scanning Electron Microscopy (SEM) and  Fourier Transform Infrared Spectroscopy (FT-IR);

  • Influence of the manufacturing process on the biological properties of CaP ceramics.