Microencapsulation for cell implants into the central nervous system: the importance of alginate viscosity and...

We have developed microcapsules using sodium alginate and poly-L-lysine with optimal combinations of experimental parameters and also used different autoclave times to evaluate the impact of sterilization on the property of capsules. We found that an autoclave time of 20 min was sufficient for sterilization of the alginate, and the optimal concentration of the alginate of low and high viscosity was 1.75 and 1.25% respectively. The capsules made with those optimal parameters remained intact for 6 months in an environment resembling that of the brain. Our results suggest that it is important to optimally combine experimental parameters in order to obtain reliable microcapsules, which may be used for many secretory cell implantats into the central nervous system in vivo.