Figure 1. A cartoon of the modular microfluidic system (Image credit: Pitingolo etc, Journal of Micromechanics and Microengineering)

Exploiting a magnetic process, IIT (Istituto Italiano di tecnologia) researchers have developed a modular and reusable hybrid chip for cell culture useful to develop tissue on a chip, as the authors show in the paper entitled “Fabrication of a modular hybrid chip to mimic endothelial-lined micro vessels in flow conditions”.

Microfluidic chips for cell culture are traditionally bonded using irreversible process, such as plasma or solvent evaporation method. The disadvantage of these methods is represented by an irreversible sealing which prevents internal accessibility as well as reuse of the chip. Recently, Pitingolo G. and co-workers have designed and developed a modular hybrid chip with circular shaped micro channel, bonded via magnetic force enhancing the sealing in flow and cell culture conditions. In particular, the research group at Istituto Italiano di tecnologia demonstrates that, by exploiting a hybrid configuration, PMMA-PDMS, combined with magnetic force. It is possible to obtain a strong sealing and guarantee a great confinement of cells in the micro channel.

The modular chip is fabricated using the following steps:

1. Fabrication of square microchannels and magnets inserts via micromilling
2. Formation of semicircular microchannels via spin coating of PDMS prepolymer
3. Integration of magnets into the PMMA substrates
4. Magnetic bonding of the hybrid substrates
5. Seeding of endothelial cells
6. De-lamination process for cell characterization

As biological assay, the authors tested the potential applicability of the proposed microfluidic system to sustain growth and formation of an endothelium in vitro, choosing to work with brain endothelial cells as a model of endothelial tissue and, in particular, of the blood brain barrier (BBB) that currently represents one of the main goals of many therapeutic strategies and biomedical applications. BEnd.3 cells were able to adhere and grow into the innovative modular system, and z-section demonstrates the uniformity along the circular shape. In particular, after 72 hours of static culture, cells were well adhered and homogeneously distributed inside the modular hybrid chip as schematized in the cartoon shown in figure 1. Conversely, when cultured into a mono-material chip, cell adhesion spreading and proliferation were less efficient, as expected by the observed leakage. In particular, Pitingolo and co-workers observed a high number of adhered cells in the modular hybrid chip as compared to the controls. These observations were more evident at a longer culture time (72 hours), quantifying the cell  density over time in both systems. 

More information can be found here: 

Fabrication of a modular hybrid chip to mimic endothelial-lined microvessels in flow conditions

Gabriele Pitingolo^1,2,4, Raffaele Vecchione^1,2, Andrea P Falanga ^1,2,

Daniela Guarnieri ^1,2 and Paolo A Netti ^1,2,3

1 Center for Advanced Biomaterials for Healthcare, Istituto Italiano di Tecnologia (IIT@CRIB), Largo Barsanti e Matteucci, 53, 80125—Napoli, Italy

2 Interdisciplinary Research Center on Biomaterials (CRIB), University of Naples Federico II, Naples 80125, Italy

3 Department of Chemical, Materials and Industrial Production Engineering, University of Naples Federico II, Naples 80125, Italy

4 Current address: INSERM UMR-S1147, Equipe labellisée Ligue Nationale Contre le Cancer,

Paris Descartes University, Paris, France

E-mail: gabriele.pitingolo@unina.it, gabriele.pitingolo@parisdescartes.fr and raffaele.vecchione@iit.it

Citation:  Gabriele Pitingolo et al 2017 J. Micromech. Microeng. 27 035014