Ultrastructure (or ultra-structure) is the architecture of cells and biomaterials that is visible at higher magnifications than found on a standard optical light microscope. This traditionally meant the resolution and magnification range of a conventional

transmission electron microscope Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a gr ...

(TEM) when viewing biological specimens such as

cell Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery ...

s, tissue, or organs. Ultrastructure can also be viewed with scanning electron microscopy and

super-resolution microscopy Super-resolution microscopy is a series of techniques in optical microscopy that allow such images to have resolutions higher than those imposed by the diffraction limit, which is due to the diffraction of light. Super-resolution imaging techni ...

, although TEM is a standard

histology Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures vis ...

technique for viewing ultrastructure. Such cellular structures as

organelle In cell biology, an organelle is a specialized subunit, usually within a cell, that has a specific function. The name ''organelle'' comes from the idea that these structures are parts of cells, as organs are to the body, hence ''organelle,'' the ...

s, which allow the cell to function properly within its specified environment, can be examined at the ultrastructural level. Ultrastructure, along with

molecular phylogeny Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

, is a reliable

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

way of classifying organisms. Features of ultrastructure are used industrially to control material properties and promote biocompatibility.

History

In 1931,

German German(s) may refer to: * Germany (of or related to) ** Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

engineers Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the limit ...

Max Knoll Max Knoll (17 July 1897 – 6 November 1969) was a German electrical engineer. Knoll was born in Wiesbaden and studied in Munich and at the Technical University of Berlin, where he obtained his doctorate in the Institute for High Voltage T ...

and

Ernst Ruska Ernst August Friedrich Ruska (; 25 December 1906 – 27 May 1988) was a German physicist who won the Nobel Prize in Physics in 1986 for his work in electron optics, including the design of the first electron microscope. Life and career Erns ...

invented the first electron microscope. With the development and invention of this microscope, the range of observable structures that were able to be explored and analyzed increased immensely, as biologists became progressively interested in the submicroscopic organization of cells. This new area of research concerned itself with substructure, also known as the ultrastructure.

Applications

Many scientists use ultrastructural observations to study the following, including but not limited to: * Human Tumors *

Chloroplast A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it in ...

s *

Bone A bone is a Stiffness, rigid Organ (biology), organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red blood cell, red and white blood cells, store minerals, provid ...

Platelet Platelets, also called thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are a component of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping, thereby ini ...

s *

Sperm Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, whi ...

Biology

A common ultrastructural feature found in

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...

cells is the formation of

calcium oxalate Calcium oxalate (in archaic terminology, oxalate of lime) is a calcium salt of oxalic acid with the chemical formula . It forms hydrates , where ''n'' varies from 1 to 3. Anhydrous and all hydrated forms are colorless or white. The monohydrate ...

crystals. It has been theorized that these crystals function to store calcium within the cell until it is needed for growth or development. Calcium oxalate crystals can also form in

animal Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...

s, and

kidney stones Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the body in the urine s ...

are a form of these ultrastructural features. Theoretically,

nanobacteria ''Nanobacterium'' ( , pl. ''nanobacteria'' ) is the unit or member name of a former proposed class of living organisms, specifically cell-walled microorganisms, now discredited, with a size much smaller than the generally accepted lower limit ...

could be used to decrease the formation of calcium oxalate kidney stones.

Engineering

Controlling ultrastructure has

engineering Engineering is the use of scientific method, scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad rang ...

uses for controlling the behavior of cells. Cells respond readily to changes in their

extracellular matrix In biology, the extracellular matrix (ECM), also called intercellular matrix, is a three-dimensional network consisting of extracellular macromolecules and minerals, such as collagen, enzymes, glycoproteins and hydroxyapatite that provide stru ...

(ECM), so manufacturing materials to mimic ECM allows for increased control over the cell cycle and

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

expression. Many cells, such as plants, produce

crystals, and these crystals are usually considered ultrastructural components of plant cells. Calcium oxalate is a material that is used to manufacture

ceramic glaze Ceramic glaze is an impervious layer or coating of a vitreous substance which has been fused to a pottery body through firing. Glaze can serve to color, decorate or waterproof an item. Glazing renders earthenware vessels suitable for holding ...

s and it also has

biomaterial A biomaterial is a substance that has been engineered to interact with biological systems for a medical purpose, either a therapeutic (treat, augment, repair, or replace a tissue function of the body) or a diagnostic one. As a science, biomateria ...

properties. For culturing cells and

tissue engineering Tissue engineering is a biomedical engineering discipline that uses a combination of Cell (biology), cells, engineering, Materials science, materials methods, and suitable biochemistry, biochemical and physicochemical factors to restore, maintai ...

, this crystal is found in

fetal bovine serum Fetal bovine serum (FBS) is derived from the blood drawn from a bovine fetus via a closed system of collection at the slaughterhouse. Fetal bovine serum is the most widely used serum-supplement for the in vitro cell culture of eukaryotic cells. Th ...

, and is an important aspect of the extracellular matrix for culturing cells. Ultrastructure is an important factor to consider when engineering

dental implant A dental implant (also known as an endosseous implant or fixture) is a prosthesis that interfaces with the bone of the jaw or skull to support a dental prosthesis such as a crown, bridge, denture, or facial prosthesis or to act as an orthodonti ...

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 Osseointegration (from Latin ''osseus'' " bony" and ''integrare'' "to make whole") is the direct structural and functional connection between living bone and the surface of a load-bearing artificial implant ("load-bearing" as defined by Albrekt ...

with

facial bones The facial skeleton comprises the ''facial bones'' that may attach to build a portion of the skull. The remainder of the skull is the braincase. In human anatomy and development, the facial skeleton is sometimes called the ''membranous viscerocr ...

. Analyzing the ultrastructure surrounding an implant is useful in determining how

biocompatible Biocompatibility is related to the behavior of biomaterials in various contexts. The term refers to the ability of a material to perform with an appropriate host response in a specific situation. The ambiguity of the term reflects the ongoing de ...

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.

Hydroxyapatite Hydroxyapatite, also called hydroxylapatite (HA), is a naturally occurring mineral form of calcium apatite with the formula Ca5(PO4)3(OH), but it is usually written Ca10(PO4)6(OH)2 to denote that the crystal unit cell comprises two entities. ...

is a biomaterial used to interface medical devices directly to bone by ultrastructure.

Grafts Grafting refers to a surgical procedure to move tissue from one site to another on the body, or from another creature, without bringing its own blood supply with it. Instead, a new blood supply grows in after it is placed. A similar techniqu ...

can be created along with 𝛃-tricalcium phosphate, and it has been observed that surrounding bone tissue with incorporate the new material into its extracellular matrix. Hydroxyapatite is a highly biocompatible material, and its ultrastructural features, such as crystalline orientation, can be controlled carefully to ensure optimal biocompatibility.Zhuang, Zhi, Takuya Miki, Midori Yumoto, Toshiisa Konishi, and Mamoru Aizawa. "Ultrastructural Observation of Hydroxyapatite Ceramics with Preferred Orientation to A-plane Using High-resolution Transmission Electron Microscopy." ''Procedia Engineering'' 36 (2012): 121-27. doi:10.1016/j.proeng.2012.03.019. 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.

References

External links

*{{Commonscat-inline Electron microscopy Cell anatomy