New revolutionary injectable microcarrier

Scaffolds or matrices based on extracellular matrix (ECM)-inspired biomaterials play a central role in the repair of tissue damage. Cell matrices can optimise the physiologically relevant 3D microenvironment of the cells and prevent graft cell death.

Autologous or allogeneic cell therapies have the potential to treat a broad range of unmet medical needs. For the commercialisation of cell therapy products, it is important to develop scalable, safe, and efficient manufacturing processes for the production of the required cell numbers. Microcarriers are commonly used in large-scale cell production and provide an attractive tool to expand cells in a 3D microenvironment as they provide a higher cell culture surface area and a closer mimic to the in vivo situation in comparison with classical 2D cell culturing methods. Especially anchorage dependent cells need such a physiologically relevant 3D microenvironment for optimal cell viability, morphology, and proliferation.

Cell harvesting is considered one of the main obstacles of using microcarriers. Dissociation of cells from the carrier is difficult due to the (high) cell attachment. Cell harvesting adds complexity and expenses to the cell production and it lowers the cell yield and may harm cell quality. With Fujifilm’s new injectable microcarrier cell harvesting can be avoided. The cell-loaded microcarriers have the unique advantage of being at the same time a cell delivery system to damaged or degenerated tissue. Injection of cells together with the biomaterial enhances cell survival, as the cells are already adhered to an ECM-like biomaterial while entering the hostile environment. Injection of cells without microcarrier often leads to poor cell survival as cells do not immediately attach to the ECM.

3D cell expansion of MSCs

Injectable microcarriers constitute a possible solution for minimally invasive simultaneous delivery of cells and scaffold. For C2C12 mouse myoblast cells and hBMSCs (human bone marrow-derived mesenchymal stromal cells) higher cell proliferation on FUJIFILM macro-porous microspheres were found compared to a commercially available equivalent micro-carrier. Moreover, the stemness and function of the hBMSCs after dynamic cell culturing were retained, making these cell loaded microcarriers very suitable as injectable cell delivery system for therapeutic applications.

3D cell expansion of MSCs

Source:
D. Confalonieri, M. La Marca, E.M.W.M. van Dongen, H. Wallis, F. Ehlicke, An Injectable Recombinant Collagen I Peptide–Based Macroporous Microcarrier Allows Superior Expansion of C2C12 and Human Bone Marrow-Derived Mesenchymal Stromal Cells and Supports Deposition of Mineralized Matrix, Tissue Engineering Part A. September 2017, 23(17-18): 946-957

Cells on Fujifilm microspheres maintain their phenotype

showcase2 Vascularization is considered as one of the most important and challenging prerequisites for improving the success rate of implanted constructs. Fujifilm microcarriers were used for expanding human dermal microvascular endothelial cells (HDMECs ). HDMECs were able to grow, proliferate and maintain their functionality when cultured on the macroporous microspheres. An increase in number of cells was observed under dynamic cell conditions. As is shown in the picture, a sprouting assay confirmed the preservation of the cellular phenotype.

Cells of FujifilmEndothelial cell colonized spheres were studied for retaining their function in a vascularized tissue equivalent, consisting of a decellularized jejunum in a perfusion bioreactor system. Fluorescently labeled endothelial cells were observed in the preserved vasculature of the biomatrix, showing that the endothelial cells were able to migrate from the microcarrier to the biomatrix, while retaining their neovessel formation function.

Altogether, these results show the potency of microcarriers seeded with endothelial cells for
1) use in endothelial cell expansion and
2) use in future clinical applications to improve vascularisation in tissue engineering applications.

 

Source:
Poster TERMIS: Melva Suarez, Muñoz Gudrun Dandekar, Heike Walles, Study of the Effect of Recombinant Collagen I Peptide Microcarriers on the Vasculogenic Potential of Human Dermal Microvascular Endothelial Cells and their use in Perfusion Bioreactor, June 2017

Upscaling and bead-to-bead transfer

The possibility to scale-up the microcarrier cultures of anchorage-dependent animal cells by intermittent agitation was investigated using fluorescent fibroblasts.

In separate spinner flasks, red and green fluorescent labeled fibroblasts were cultured on macroporous microspheres. After 7 days of culture, the red and green labeled cells had colonized the microbeads. Both red and green cell loaded microspheres then were mixed together, and additional empty microspheres were added. This procedure allowed the microbeads to contact each other and the fluorescent cells to migrate from colonized microcarriers to empty microspheres.

The mixed microbeads were continually agitated and cultured for an additional period of 7 days. At day 14, it was possible to obtain a clear visual evidence of the bead-to-bead transfer. Red and green labeled cells were found attached to a single microbead, as is shown in the picture.

The ability of cells to migrate from one bead to another suggests macroporous beads can be used in larger scale dynamic cell culturing.

Upscaling and bead to bead transfer