A transplantation material has been developed that gradually releases stem cells to repair damaged tissue.
Cell therapy is a promising method of regenerating damaged tissue, but the method for the input of the cells thus far works poorly, leading to low survival rate of or scattering of the transplanted stem cells, meaning that the effectiveness at the site of injury is not enough for the desired clinical effect.
American scientists from the Georgia Institute of Technology have developed a biodegradable injectable alginate hydrogel that allows for the release and distribution of stem cells used to regenerate bone tissue at a gradual rate. The proposed material takes the form of balls with a diameter <200μm, which may be introduced at the site of the damage and remain there for a long time until they undergo biodegradation, and the cells distributed from the balls remain viable. Scientists have proposed the gradual release of cells from alginate micro beads added to an alginate-lyase hydrogel. The balls are formed using a high electrostatic potential, and their controlled biodegradation achieved through a combination of alginate-lyase and alginate at 4 ° C. The results showed that the rate of degradation of micro balls and the release of cells depended on the ratio of the content of alginate hydrogels and alginate-lyase. The viability of cells being released from the balls ranged from 87% the day after transplantation and up to 71% – on the 12th day. Cultured cells grown in an osteogenic medium produced higher levels of osteocalcin and similar levels of other soluble factors as cells that were neither previously encapsulated nor exposed to alginate-lyase. Also increased in the released were levels of Bmp2, Fgf2, and Vegfa mRNA. Thus, under the proposed release system, stem cells can be controlled to produce viable cells and the osteogenic growth factors later can be modulated.
Research materials are presented in this article; http://www.ncbi.nlm.nih.gov/pubmed/23906513