Preparation of Cell-Loaded Microbeads as Stable and Injectable Delivery Platforms for Tissue Engineering

Cell transplants in therapeutic studies are not preserving their long term functional inside the donor body. In mesenchymal stem cells transplants, transplanted cells disperse through body and easily degraded by immune cells after transplant process. Various strategies such as usage of the immunosuppressive drug to eliminate allograft rejection are designed to increase efficiency of the cell therapy. The other hand strategy is the construction of biomimetic encapsulates via using polymeric materials which preserve of stem cells from environmental effect. In this study, we hypothesize that L929 cell lines and mesenchymal stem cell (MSCs) might continue their viability and functionality inside the alginate microbeads during the 12 days of in vitro conditions. For that purpose, uniform, and injectable size (<200 µm) of cell-loaded microbeads were constructed by electrostatically assisted spraying techniques. Our results showed that both L929 and MSCs cell lines continue their metabolic activity inside the microbeads and cells during the incubation periods. Glucose consumption and lactic acid production level of both groups of the cell lines were consistently observed. Released cell number at day 12 was increased compared to day 0. Protein expression of both groups of the cells was increased day by day with doubling of the cell number. In this work, we illustrate that mesenchymal stem cells and L929 cells might be used in 3D cell culture models.