Editing Tissue engineering (section)

=== Genetic classifications of cells ===

Autologous: The donor and the recipient of the cells are the same individual. Cells are harvested, cultured or stored, and then reintroduced to the host. As a result of the host's own cells being reintroduced, an antigenic response is not elicited. The body's immune system recognizes these re-implanted cells as its own, and does not target them for attack. Autologous cell dependence on host cell health and donor site morbidity may be deterrents to their use. Adipose-derived and bone marrow-derived mesenchymal stem cells are commonly autologous in nature, and can be used in a myriad of ways, from helping repair skeletal tissue to replenishing beta cells in diabetic patients.<ref>{{cite journal | vauthors = Parekkadan B, Milwid JM | title = Mesenchymal stem cells as therapeutics | journal = Annual Review of Biomedical Engineering | volume = 12 | pages = 87–117 | date = August 2010 | pmid = 20415588 | doi = 10.1146/annurev-bioeng-070909-105309 | pmc = 3759519 }}</ref><ref>{{cite journal | vauthors = Domínguez-Bendala J, Lanzoni G, Inverardi L, Ricordi C | title = Concise review: mesenchymal stem cells for diabetes | journal = Stem Cells Translational Medicine | volume = 1 | issue = 1 | pages = 59–63 | date = January 2012 | pmid = 23197641 | doi = 10.5966/sctm.2011-0017 | pmc = 3727686 }}</ref><ref>{{cite journal | vauthors = Bara JJ, Richards RG, Alini M, Stoddart MJ | title = Concise review: Bone marrow-derived mesenchymal stem cells change phenotype following in vitro culture: implications for basic research and the clinic | journal = Stem Cells | volume = 32 | issue = 7 | pages = 1713–23 | date = July 2014 | pmid = 24449458 | doi = 10.1002/stem.1649 | s2cid = 30744973 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Minteer D, Marra KG, Rubin JP | title = Adipose-derived mesenchymal stem cells: biology and potential applications | journal = Advances in Biochemical Engineering/Biotechnology | volume = 129 | pages = 59–71 | date = 2013 | pmid = 22825719 | doi = 10.1007/10_2012_146 | isbn = 978-3-642-35670-4 }}</ref>

Allogenic: Cells are obtained from the body of a donor of the same species as the recipient. While there are some ethical constraints to the use of human cells for in vitro studies (i.e. human brain tissue chimera development<ref>{{cite journal | vauthors = Farahany NA, Greely HT, Hyman S, Koch C, Grady C, Pașca SP, Sestan N, Arlotta P, Bernat JL, Ting J, Lunshof JE, Iyer EP, Hyun I, Capestany BH, Church GM, Huang H, Song H | display-authors = 6 | title = The ethics of experimenting with human brain tissue | journal = Nature | volume = 556 | issue = 7702 | pages = 429–32 | date = April 2018 | pmid = 29691509 | doi = 10.1038/d41586-018-04813-x | pmc = 6010307 | bibcode = 2018Natur.556..429F }}</ref>), the employment of dermal fibroblasts from human foreskin demonstrates an immunologically safe and thus a viable choice for allogenic tissue engineering of the skin.

Xenogenic: These cells are derived isolated cells from alternate species from the recipient. A notable example of xenogeneic tissue utilization is cardiovascular implant construction via animal cells. Chimeric human-animal farming raises ethical concerns around the potential for improved consciousness from implanting human organs in animals.<ref>{{cite journal | vauthors = Bourret R, Martinez E, Vialla F, Giquel C, Thonnat-Marin A, De Vos J | title = Human-animal chimeras: ethical issues about farming chimeric animals bearing human organs | journal = Stem Cell Research & Therapy | volume = 7 | issue = 1 | pages = 87 | date = June 2016 | pmid = 27356872 | doi = 10.1186/s13287-016-0345-9 | pmc = 4928294 | doi-access = free }}</ref>

Syngeneic or isogenic: These cells describe those borne from identical genetic code. This imparts an immunologic benefit similar to autologous cell lines (see above).<ref>{{cite book | vauthors = Murphy K | date=  2016 | title= Janeway's Immunobiology | publisher= Norton, W.W. & Company, Inc.| isbn=978-0815345053}}{{page needed|date=July 2021}}</ref> Autologous cells can be considered syngenic, but the classification also extends to non-autologously derived cells such as those from an identical twin, from genetically identical (cloned) research models, or [[Induced stem cells|induced stem cells (iSC)]]<ref>{{cite journal | vauthors = Grobarczyk B, Franco B, Hanon K, Malgrange B | title = Generation of Isogenic Human iPS Cell Line Precisely Corrected by Genome Editing Using the CRISPR/Cas9 System | journal = Stem Cell Reviews and Reports | volume = 11 | issue = 5 | pages = 774–87 | date = October 2015 | pmid = 26059412 | doi = 10.1007/s12015-015-9600-1 | s2cid = 18897400 }}</ref> as related to the donor.