Editing Ultrastructure (section)

== Engineering ==
Controlling ultrastructure has [[engineering]] uses for controlling the behavior of cells. Cells respond readily to changes in their [[extracellular matrix]] (ECM), so manufacturing materials to mimic ECM allows for increased control over the cell cycle and [[protein]] expression.<ref>{{cite book |last=Khademhosseini |first=Ali |year=2008 |title=Micro and nanoengineering of the cell microenvironment: technologies and applications |location=Boston |publisher=Artech House |url=http://public.eblib.com/choice/publicfullrecord.aspx?p=456882 | isbn=978-1-59693-149-7}}</ref>

Many cells, such as plants, produce [[calcium oxalate]] crystals, and these crystals are usually considered ultrastructural components of plant cells. Calcium oxalate is a material that is used to manufacture [[ceramic glaze]]s [6], and it also has [[biomaterial]] properties. For [[Cell culture|culturing cells]] and [[tissue engineering]], this crystal is found in [[fetal bovine serum]], and is an important aspect of the extracellular matrix for culturing cells.<ref>{{cite journal | last1=Pedraza | first1=Claudio E. | last2=Chien | first2=Yung‐Ching | last3=McKee | first3=Marc D. | title=Calcium oxalate crystals in fetal bovine serum: Implications for cell culture, phagocytosis and biomineralization studies in vitro | journal=Journal of Cellular Biochemistry | volume=103 | issue=5 | date=2008 | issn=0730-2312 | doi=10.1002/jcb.21515 | pages=1379–1393| pmid=17879965 | s2cid=43217705 }}</ref> 

Ultrastructure is an important factor to consider when engineering [[dental implant]]s. Since these devices interface directly with bone, their incorporation to surrounding tissue is necessary to optimal device function. It has been found that applying a load to a healing dental implant allows for increased [[osseointegration]] with [[Facial skeleton|facial bones]].<ref>{{cite journal | last1=Meyer | first1=U. | last2=Joos | first2=U. | last3=Mythili | first3=J. | last4=Stamm | first4=T. | last5=Hohoff | first5=A. | last6=Fillies | first6=T. | last7=Stratmann | first7=U. | last8=Wiesmann | first8=H.P. | title=Ultrastructural characterization of the implant/bone interface of immediately loaded dental implants | journal=Biomaterials | volume=25 | issue=10 | date=2004 | doi=10.1016/j.biomaterials.2003.08.070 | pages=1959–1967| pmid=14738860 }}</ref> Analyzing the ultrastructure surrounding an implant is useful in determining how [[Biocompatibility|biocompatible]] it is and how the body reacts to it. One study found implanting granules of a biomaterial derived from pig bone caused the human body to incorporate the material into its ultrastructure and form new bone.<ref>{{cite journal | last1=Orsini | first1=Giovanna | last2=Scarano | first2=Antonio | last3=Piattelli | first3=Maurizio | last4=Piccirilli | first4=Marcello | last5=Caputi | first5=Sergio | last6=Piattelli | first6=Adriano | title=Histologic and Ultrastructural Analysis of Regenerated Bone in Maxillary Sinus Augmentation Using a Porcine Bone–Derived Biomaterial | journal=Journal of Periodontology | volume=77 | issue=12 | date=2006 | issn=0022-3492 | doi=10.1902/jop.2006.060181 | pages=1984–1990| pmid=17209782 }}</ref>

[[Hydroxyapatite]] is a biomaterial used to interface medical devices directly to bone by ultrastructure. [[Graft (surgery)|Grafts]] can be created along with [[Tricalcium phosphate|𝛃-tricalcium phosphate]], and it has been observed that surrounding bone tissue with incorporate the new material into its extracellular matrix.<ref>{{cite journal | last1=Fujita | first1=Rumi | last2=Yokoyama | first2=Atsuro | last3=Nodasaka | first3=Yoshinobu | last4=Kohgo | first4=Takao | last5=Kawasaki | first5=Takao | title=Ultrastructure of ceramic-bone interface using hydroxyapatite and β-tricalcium phosphate ceramics and replacement mechanism of β-tricalcium phosphate in bone | journal=Tissue and Cell | volume=35 | issue=6 | date=2003 | doi=10.1016/S0040-8166(03)00067-3 | pages=427–440| pmid=14580356 }}</ref> Hydroxyapatite is a highly biocompatible material, and its ultrastructural features, such as crystalline orientation, can be controlled carefully to ensure optimal biocompatibility.<ref>{{cite journal | last1=Zhuang | first1=Zhi | last2=Miki | first2=Takuya | last3=Yumoto | first3=Midori | last4=Konishi | first4=Toshiisa | last5=Aizawa | first5=Mamoru | title=Ultrastructural Observation of Hydroxyapatite Ceramics with Preferred Orientation to a-plane Using High-resolution Transmission Electron Microscopy | journal=Procedia Engineering | volume=36 | date=2012 | doi=10.1016/j.proeng.2012.03.019 | pages=121–127| doi-access=free }}</ref> Proper crystal fiber orientation can make introduced minerals, like hydroxyapatite, more similar to the biological materials they intend to replace. Controlling ultrastructural features makes obtaining specific material properties possible.