Micropatterning

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File:Micropatterns-fibronectin-glass.png

Micropatterning is the art of miniaturisation of patterns. Especially used for electronics, it has recently{{when|date=May 2011}} become a standard in biomaterials engineering and for fundamental research on cellular biology by mean of soft lithography. It generally uses photolithography methods but many techniques have been developed.{{cite journal | pmid = 17538708 | doi=10.1039/b618545b | volume=7 | issue=6 | title=Comparative study and improvement of current cell micro-patterning techniques. | date=Jun 2007 | journal=Lab Chip | pages=672–80 | last1 = Fink | first1 = J | last2 = Théry | first2 = M | last3 = Azioune | first3 = A | last4 = Dupont | first4 = R | last5 = Chatelain | first5 = F | last6 = Bornens | first6 = M | last7 = Piel | first7 = M}}

In cellular biology, micropatterns can be used to control the geometry of adhesion and substrate rigidity. This tool helped scientists to discover how the environment influences processes such as the orientation of the cell division axis, organelle positioning, cytoskeleton rearrangement cell differentiation and directionality of cell migration.{{cite journal | volume=447 | issue=7143 | doi = 10.1038/nature05786 | title=Experimental and theoretical study of mitotic spindle orientation | journal=Nature | pages=493–496 | pmid=17495931 | last1 = Théry | first1 = M | last2 = Jiménez-Dalmaroni | first2 = A | last3 = Racine | first3 = V | last4 = Bornens | first4 = M | last5 = Jülicher | first5 = F| year=2007 | bibcode=2007Natur.447..493T | s2cid=4391685 }}

{{cite journal | pmc = 4446331 | pmid=26016478 | doi=10.1371/journal.pcbi.1004245 | volume=11 | issue=5 | title=Geometrical and mechanical properties control actin filament organization | year=2015 | journal=PLOS Comput. Biol. | pages=e1004245 | last1 = Letort | first1 = G | last2 = Politi | first2 = AZ | last3 = Ennomani | first3 = H | last4 = Théry | first4 = M | last5 = Nedelec | first5 = F | last6 = Blanchoin | first6 = L| bibcode=2015PLSCB..11E4245L | doi-access=free }}

Micropatterns can be made on a wide range of substrates, from glass to polyacrylamide and polydimethylsiloxane (PDMS). The polyacrylamide and PDMS in particular come into handy because they let scientists specifically regulate the stiffness of the substrate, and they allow researchers to measure cellular forces (traction force microscopy). Advanced custom micropatterning{{Cite web|url=https://snf.stanford.edu/SNF/equipment/nSiL/alveole-primo|title=Protein Patterning Protocol|website=Stanford Nanofabrication Facility}} allow precise and relatively rapid experiments controlling cell adhesion, cell migration, guidance, 3D confinement and microfabrication of microstructured chips.{{Cite web|url=https://www.alveolelab.com/fields-of-application/|title=Alveole Lab, Fields of Application|website=Alveole Lab}} Using advanced tools, protein patterns can be produced in virtually unlimited numbers (2D/ 3D shapes and volumes).

Nanopatterning of proteins has been achieved through using top-down lithography techniques.{{Cite journal|last1=Shafagh|first1=Reza|last2=Vastesson|first2=Alexander|last3=Guo|first3=Weijin|last4=van der Wijngaart|first4=Wouter|last5=Haraldsson|first5=Tommy|year=2018|title=E-Beam Nanostructuring and Direct Click Biofunctionalization of Thiol–Ene Resist|journal=ACS Nano|volume=12|issue=10|pages=9940–9946|language=en|doi=10.1021/acsnano.8b03709|pmid=30212184|s2cid=52271550 |url=http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-236089}}

Aerosol micropatterning for biomaterials uses spray microscopic characteristics to obtain semi-random patterns particularly well adapted for biomaterials.