Lipid membrane nanotubes (NTs) are a widespread template for in vitro studies of cellular processes happening at high membrane curvature. Traditionally NTs are manufactured one by one, using sophisticated membrane micromanipulations, while simplified methods for controlled batch production of NTs are in growing demand. Here we propose a lab-on-a-chip (LOC) approach to the simultaneous formation of multiple NTs with length and radius controlled by the chip design. The NTs form upon rolling silica microbeads covered by lipid lamellas over the pillars of a polymer micropillar array. The array's design and surface chemistry set the geometry of the resulting free-standing NTs. The integration of the array inside a microfluidic chamber further enables fast and turbulence-free addition of components, such as proteins, to multiple preformed NTs. This LOC approach to NT production is compatible with the use of high power objectives of a fluorescence microscope, making real-time quantification of the different modes of the protein activity in a single experiment possible.

Microencapsulation of pancreatic islets for the treatment of Type I Diabetes Mellitus (T1DM) generates a high

quantity of empty microcapsules, resulting in high therapeutic graft volumes that can enhance the host

’

s immune

response. We report a 3D printed micro

fl

uidic magnetic sorting device for microcapsules puri

fi

cation with the

objective to reduce the number of empty microcapsules prior transplantation. In this study, INS1E pseudoislets

were microencapsulated within alginate (A) and alginate-poly-L-lysine-alginate (APA) microcapsules and pur-

i

fi

ed through the micro

fl

uidic device. APA microcapsules demonstrated higher mechanical integrity and stability

than A microcapsules, showing better pseudoislets viability and biological function. Importantly, we obtained a

reduction of the graft volume of 77.5% for A microcapsules and 78.6% for APA microcapsules. After sub-

cutaneous implantation of induced diabetic Wistar rats with magnetically puri

fi

ed APA microencapsulated

pseudoislets, blood glucose levels were restored into normoglycemia (< 200 mg/dL) for almost 17 weeks. In

conclusion, our described micro

fl

uidic magnetic sorting device represents a great alternative approach for the

graft volume reduction of microencapsulated pseudoislets and its application in T1DM disease.