The present paper reports the production of Ba-alginate microspheres by microfluidic chip technology. The general production strategy is based on the formation of an alginate multiphase flow by a 'Y' junction squeezing mechanism. Special emphasis is given to the relationship existing between the gelation process and the final morphological characteristics of the produced microbeads. A series of different gelation strategies, namely: 'external gelation', 'internal gelation' and 'partial gelation' were compared in terms of size, size distribution and morphology of the produced microbeads.

The optimization, through a Design of Experiments (DoE) approach, of a microencapsulation procedure for isolated neonatal porcine islets (NPI) is described. The applied method is based on the generation of monodisperse droplets by a vibrational nozzle. An alginate/polyornithine encapsulation procedure, developed and validated in our laboratory for almost a decade, was used to embody pancreatic islets. We analyzed different experimental parameters including frequency of vibration, amplitude of vibration, polymer pumping rate, and distance between the nozzle and the gelling bath. We produced calcium-alginate gel microbeads with excellent morphological characteristics as well as a very narrow size distribution. The automatically produced microcapsules did not alter morphology, viability

This paper describes a design of experiments (DoE) approach, of an automatic procedure for the microencapsulation of isolated neonatal porcine islets (NPI). Monodisperse droplets were prepared by a vibrational nozzle, using an alginate/polyornithine encapsulation procedure, that has been developed and validated in our laboratory to encapsulate pancreatic islets. Different experimental parameters were considered such as: frequency of vibration, amplitude of vibration, polymer pumping rate and distance between the nozzle and the gelling bath. The produced calcium-alginate gel microbeads displayed an excellent morphology as well as a very narrow size distribution. The automatically produced microcapsules did not alter morphology and viability and functional properties of the enveloped NPI. The optimization of this automatic procedure may provide a novel approach to obtain a large number of batches possibly suitable for large scale production of immunoisolated NPI for in vivo cell transplantation procedures in humans.