Insights in Behavior of Variably Formulated Alginate-Based Microcapsules for Cell Transplantation

Figure 2

In vitro evaluation of microcapsules. (a) The microcapsules gelled with indicated conterions 7 months after gelification and maintained in saline at +4°C maintain a spherical and smooth shape. (b) Distribution of diameters’ size over the time for each microcapsule’s type at +4°C. All microcapsules show the aptitude to decrement their diameter both over time () and between ions (). (c) The diameter sizes show similar differences over time () and between ions () in both left (+4°C) and middle (+37°C) panels; the temperature is irrelevant on diameters’ decrement for microcapsules made with various gelling solutions, as shown in the right panel in which, considering all the ions together, the within-subjects effect (time) is still significant (), whilst the between-subjects effect (temperature) is not significant (). (d) Microcapsules left O/N in gelling solution swell when saline solution was changed as indicated in figure both over time () and between ions (). (e) The illustrated graph summarizes at once, using the same capsules, some of the experiments carried out throughout this report. The initial part of the graph shows capsules maintained in saline for 7 months. The second part shows the experiment elsewhere named “fake saline changes,” while the last part coincides with the swelling test performed by changing saline at fixed times. Finally, the capsules have been left to rest in saline, like the beginning of the experiment. Looking at the graph, during the “fake saline changes” the capsules’ diameters did not vary compared to the values seen after 7 months of incubation. Two actual changes of saline were performed; all capsules’ types tended to increase their diameter. The capsules then were incubated for 1 hour at 4°C, overnight, or for 10 days with no saline changes. From the graph, it appears that the capsules tend to stabilize their diameters which eventually tend to decrease again.

(a)

(b)

(c)

(d)

(e)