Editing Spider silk (section)

===Geometry===
Spider silks with comparatively simple molecular structure need complex ducts to be able to form an effective fibre. Approaches:

====Syringe and needle====
Feedstock is forced through a hollow needle using a syringe.<ref name="Lazaris 02">{{cite journal |author= Lazaris, A.|date= 2002 |title= Spider silk fibers spun from soluble recombinant silk produced in mammalian cells |journal= Science |volume= 295 |pages= 472–76 |doi=10.1126/science.1065780 |pmid=11799236|bibcode = 2002Sci...295..472L |issue= 5554 |first2= S |first3= Y |first4= JF |first5= F |first6= N |first7= EA |first8= JW |first9= CN  |last2= Arcidiacono, S |last3= Huang, Y |last4= Zhou, J. F. |last5= Duguay, F |last6= Chretien, N |last7= Welsh, E. A. |last8= Soares, J. W. |last9= Karatzas, C. N. |s2cid= 9260156 }}</ref><ref name="Seidel 00">{{cite journal |author= Seidel, A.|date= 2000 |title= Regenerated spider silk: Processing, properties, and structure |journal= Macromolecules |volume= 33 |pages= 775–80 |doi=10.1021/ma990893j |bibcode = 2000MaMol..33..775S |first2= Oskar |last3= Calve |first3= Sarah |last4= Adaska |first4= Jason |last5= Ji |first5= Gending |last6= Yang |first6= Zhitong |last7= Grubb |first7= David |last8= Zax |first8= David B. |last9= Jelinski |first9= Lynn W. |issue= 3 |last2= Liivak  }}</ref>

Although cheap and easy to produce, gland shape and conditions are loosely approximated. Fibres created using this method may need encouragement to solidify by removing water from the fibre with chemicals such as (environmentally undesirable) [[methanol]]<ref>{{cite journal |author= Arcidiacono, S.|date= 2002 |title= Aqueous processing and fiber spinning of recombinant spider silks |journal= Macromolecules |volume= 35 |pages= 1262–66 |doi=10.1021/ma011471o |bibcode = 2002MaMol..35.1262A |first2= Charlene M. |last3= Butler |first3= Michelle |last4= Welsh |first4= Elizabeth |last5= Soares |first5= Jason W. |last6= Allen |first6= Alfred |last7= Ziegler |first7= David |last8= Laue |first8= Thomas |last9= Chase |first9= Susan |issue= 4 |last2= Mello  }}</ref> or [[acetone]],<ref name="Seidel 00"/> and also may require later stretching of the fibre to achieve desirable properties.<ref name="Xia 10">{{cite journal |author= Xia, X. X.|date= 2010 |title= Native-sized recombinant spider silk protein produced in metabolically engineered Escherichia coli results in a strong fiber |journal= Proceedings of the National Academy of Sciences of the United States of America |volume= 107 |pages= 14,059–63 |doi= 10.1073/pnas.1003366107|bibcode = 2010PNAS..10714059X |issue= 32 |display-authors=etal |pmid=20660779 |pmc=2922564|doi-access= free }}</ref><ref name="Lazaris 02"/>

====Superhydrophobic surfaces====
Placing a solution of spider silk on a superhydrophobic surface can generate sheets, particles, and nanowires of spider silk.<ref>{{cite journal | author1= Gustafsson, L. | author2= Jansson, R. | author3= Hedhammar, M. | author4= van der Wijngaart, W. | date= 2018 |title= Structuring of Functional Spider Silk Wires, Coatings, and Sheets by Self-Assembly on Superhydrophobic Pillar Surfaces |journal= Advanced Materials|volume= 30 |issue= 3 |doi= 10.1002/adma.201704325 | pmid= 29205540 | bibcode= 2018AdM....3004325G | s2cid= 205283504 }}</ref><ref>{{cite journal | author1= Gustafsson, L. | author2= Kvick, M. | author3= Åstrand, C. | author4= Ponsteen, N. | author5= Dorka, N. | author6= Hegrová, V. | author7= Svanberg, S. | author8= Horák, J. | author9= Jansson, R. | author10= Hedhammar, M. | author11= van der Wijngaart, W. | date= 2023 |title= Scalable Production of Monodisperse Bioactive Spider Silk Nanowires |journal= Macromolecular Bioscience | volume= 23 | issue= 4 | pages= e2200450 | doi= 10.1002/mabi.202200450| pmid= 36662774 | s2cid= 256032679 | doi-access= free }}</ref>

====Sheets====
Self-assembly of silk at standing liquid-gas interphases of a solution tough and strong sheets. These sheets are now explored for mimicking the basal membrane in tissue modeling.<ref>{{Citation | vauthors=Gustafsson L, Tasiopoulos CP, Jansson R, Kvick M, Duursma T, Gasser TC, Wijngaart W, Hedhammar M | year=2020 | title=Recombinant Spider Silk Forms Tough and Elastic Nanomembranes that are Protein-Permeable and Support Cell Attachment and Growth |journal = Advanced Functional Materials | volume=30 | issue=40 | doi=10.1002/adfm.202002982 | s2cid=225398425 | doi-access=free }}</ref><ref>{{Citation | vauthors=Tasiopoulos CP, Gustafsson L, Wijngaart W, van der Hedhammar M | year=2021 | title=Fibrillar Nanomembranes of Recombinant Spider Silk Protein Support Cell Co-culture in an In Vitro Blood Vessel Wall Model |journal=  ACS Biomaterials Science & Engineering| volume=7 | issue=7 | pages=3332–3339 | doi=10.1021/acsbiomaterials.1c00612 | pmid=34169711 | pmc=8290846 | url=http://dx.doi.org/10.1021/acsbiomaterials.1c00612}}</ref>

====Microfluidics====
[[Microfluidics]] have the advantage of being controllable and able to test spin small volumes of unspun fibre,<ref>{{cite journal |author= Kinahan, M. E.|date= 2011 |title= Tunable Silk: Using Microfluidics to Fabricate Silk Fibers with Controllable Properties |journal= Biomacromolecules |volume= 12 |pages= 1504–11 |doi= 10.1021/bm1014624 |issue= 5 |pmid= 21438624 |pmc= 3305786|display-authors=etal}}</ref><ref>{{cite journal |author= Rammensee, S.|author2= Slotta, U.|author3= Scheibel, T.|author4= Bausch, A. R.|name-list-style= amp |date= 2008 |title= Assembly mechanism of recombinant spider silk proteins (microfluidic) |journal= Proceedings of the National Academy of Sciences of the United States of America |volume= 105 |pages= 6590–95 |doi= 10.1073/pnas.0709246105|bibcode = 2008PNAS..105.6590R |issue= 18 |pmid= 18445655 |pmc= 2373321 |doi-access= free}}</ref> but setup and development costs are high. A patent has been granted and continuously spun fibres have achieved commercial use.<ref>[http://www.spintec-engineering.de/spintec-engineering.de/Home.html Spintec Engineering GmbH] {{in lang|de}}</ref>

====Electrospinning====
[[Electrospinning]] is an old technique whereby a fluid is held in a container such that it flows out through capillary action. A conducting substrate is positioned below, and a difference in electrical potential is applied between the fluid and the substrate. The fluid is attracted to the substrate, and tiny fibres jump from their point of emission, the [[Taylor cone]], to the substrate, drying as they travel. This method creates nano-scale fibres from silk dissected from organisms and regenerated silk fibroin.{{Cn|date=January 2024}}