Bone seeker

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A bone seeker is an element, often a radioisotope, that tends to accumulate in the bones of humans and other animals when it is introduced into the body.

For example, strontium and radium are chemically similar to calcium and can replace the calcium in bones. [1] [2] Plutonium is also a bone seeker, though the mechanism by which it accumulates in bone tissue is unknown. [3]

Radioactive bone seekers are particular health risks as they irradiate surrounding tissue, though this can be useful for radiotherapy   radium-223 is used in this way. [2] [4] Stable bone seekers can also be harmful: excessive strontium absorption has been linked with increased levels of rickets. [5] [6] The salt strontium ranelate, however, is a bone seeker which is sometimes used to strengthen bones as a treatment for osteoporosis. [7] Bone seekers have been proposed as a method of delivering antibiotics to infected bone tissue. [8]

See also

Related Research Articles

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Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to more porous bone, and consequent increase in fracture risk. It is the most common reason for a broken bone among the elderly. Bones that commonly break include the vertebrae in the spine, the bones of the forearm, the wrist, and the hip. Until a broken bone occurs there are typically no symptoms. Bones may weaken to such a degree that a break may occur with minor stress or spontaneously. After the broken bone heals, the person may have chronic pain and a decreased ability to carry out normal activities.

<span class="mw-page-title-main">Rickets</span> Childhood bone disorder

Rickets is a condition that results in weak or soft bones in children, and is caused by either dietary deficiency or genetic causes. Symptoms include bowed legs, stunted growth, bone pain, large forehead, and trouble sleeping. Complications may include bone deformities, bone pseudofractures and fractures, muscle spasms, or an abnormally curved spine.

<span class="mw-page-title-main">Strontium</span> Chemical element, symbol Sr and atomic number 38

Strontium is a chemical element; it has symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is exposed to air. Strontium has physical and chemical properties similar to those of its two vertical neighbors in the periodic table, calcium and barium. It occurs naturally mainly in the minerals celestine and strontianite, and is mostly mined from these.

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Osteomalacia is a disease characterized by the softening of the bones caused by impaired bone metabolism primarily due to inadequate levels of available phosphate, calcium, and vitamin D, or because of resorption of calcium. The impairment of bone metabolism causes inadequate bone mineralization. Osteomalacia in children is known as rickets, and because of this, use of the term "osteomalacia" is often restricted to the milder, adult form of the disease. Signs and symptoms can include diffuse body pains, muscle weakness, and fragility of the bones. In addition to low systemic levels of circulating mineral ions that result in decreased bone and tooth mineralization, accumulation of mineralization-inhibiting proteins and peptides, and small inhibitory molecules, can occur in the extracellular matrix of bones and teeth, contributing locally to cause matrix hypomineralization (osteomalacia/odontomalacia). A relationship describing local, physiologic double-negative regulation of mineralization has been termed the Stenciling Principle of mineralization, whereby enzyme-substrate pairs imprint mineralization patterns into the extracellular matrix by degrading mineralization inhibitors. The Stenciling Principle for mineralization is particularly relevant to the osteomalacia and odontomalacia observed in hypophosphatasia (HPP) and X-linked hypophosphatemia (XLH).

<span class="mw-page-title-main">Bisphosphonate</span> Pharmaceutical drugs for preventing bone loss

Bisphosphonates are a class of drugs that prevent the loss of bone density, used to treat osteoporosis and similar diseases. They are the most commonly prescribed drugs used to treat osteoporosis. They are called bisphosphonates because they have two phosphonate groups. They are thus also called diphosphonates.

<span class="mw-page-title-main">Alendronic acid</span> Chemical compound

Alendronic acid, sold under the brand name Fosamax among others, is a bisphosphonate medication used to treat osteoporosis and Paget's disease of bone. It is taken by mouth. Use is often recommended together with vitamin D, calcium supplementation, and lifestyle changes.

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Calcitriol is the active form of vitamin D, normally made in the kidney. It is also known as 1,25-dihydroxycholecalciferol. It is a hormone which binds to and activates the vitamin D receptor in the nucleus of the cell, which then increases the expression of many genes. Calcitriol increases blood calcium (Ca2+) mainly by increasing the uptake of calcium from the intestines.

<span class="mw-page-title-main">Hypophosphatasia</span> Medical condition

Hypophosphatasia (; also called deficiency of alkaline phosphatase, phosphoethanolaminuria, or Rathbun's syndrome; sometimes abbreviated HPP) is a rare, and sometimes fatal, inherited metabolic bone disease. Clinical symptoms are heterogeneous, ranging from the rapidly fatal, perinatal variant, with profound skeletal hypomineralization, respiratory compromise or vitamin B6 dependent seizures to a milder, progressive osteomalacia later in life. Tissue non-specific alkaline phosphatase (TNSALP) deficiency in osteoblasts and chondrocytes impairs bone mineralization, leading to rickets or osteomalacia. The pathognomonic finding is subnormal serum activity of the TNSALP enzyme, which is caused by one of 388 genetic mutations identified to date, in the gene encoding TNSALP. Genetic inheritance is autosomal recessive for the perinatal and infantile forms but either autosomal recessive or autosomal dominant in the milder forms.

<span class="mw-page-title-main">Bone resorption</span> Medical condition

Bone resorption is resorption of bone tissue, that is, the process by which osteoclasts break down the tissue in bones and release the minerals, resulting in a transfer of calcium from bone tissue to the blood.

<span class="mw-page-title-main">Strontium ranelate</span> Chemical compound

Strontium ranelate, a strontium(II) salt of ranelic acid, is a medication for osteoporosis marketed as Protelos or Protos by Servier. Studies indicate it can also slow the course of osteoarthritis of the knee. The drug is unusual in that it both increases deposition of new bone by osteoblasts and reduces the resorption of bone by osteoclasts. It is therefore promoted as a "dual action bone agent" (DABA).

Senile osteoporosis has been recently recognized as a geriatric syndrome with a particular pathophysiology. There are different classification of osteoporosis: primary, in which bone loss is a result of aging and secondary, in which bone loss occurs from various clinical and lifestyle factors. Primary, or involuntary osteoporosis, can further be classified into Type I or Type II. Type I refers to postmenopausal osteoporosis and is caused by the deficiency of estrogen. While senile osteoporosis is categorized as an involuntary, Type II, and primary osteoporosis, which affects both men and women over the age of 70 years. It is accompanied by vitamin D deficiency, body's failure to absorb calcium, and increased parathyroid hormone.

<span class="mw-page-title-main">Medication-related osteonecrosis of the jaw</span> Medical condition

Medication-related osteonecrosis of the jaw is progressive death of the jawbone in a person exposed to a medication known to increase the risk of disease, in the absence of a previous radiation treatment. It may lead to surgical complication in the form of impaired wound healing following oral and maxillofacial surgery, periodontal surgery, or endodontic therapy.

Radium-223 is an isotope of radium with an 11.4-day half-life. It was discovered in 1905 by T. Godlewski, a Polish chemist from Kraków, and was historically known as actinium X (AcX). Radium-223 dichloride is an alpha particle-emitting radiotherapy drug that mimics calcium and forms complexes with hydroxyapatite at areas of increased bone turnover. The principal use of radium-223, as a radiopharmaceutical to treat metastatic cancers in bone, takes advantage of its chemical similarity to calcium, and the short range of the alpha radiation it emits.

<span class="mw-page-title-main">Alfacalcidol</span> Chemical compound

Alfacalcidol is an analogue of vitamin D used for supplementation in humans and as a poultry feed additive.

<span class="mw-page-title-main">Vitamin D</span> Group of fat-soluble secosteroids

Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and for many other biological effects. In humans, the most important compounds in this group are vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol).

<span class="mw-page-title-main">Osteoradionecrosis</span> Osteoradionecrosis is an Acute form of Osteomyelitis

Osteoradionecrosis (ORN) is a serious complication of radiation therapy in cancer treatment where radiated bone becomes necrotic and exposed. ORN occurs most commonly in the mouth during the treatment of head and neck cancer, and can arise over 5 years after radiation. Common signs and symptoms include pain, difficulty chewing, trismus, mouth-to-skin fistulas and non-healing ulcers.

Targeted alpha-particle therapy is an in-development method of targeted radionuclide therapy of various cancers. It employs radioactive substances which undergo alpha decay to treat diseased tissue at close proximity. It has the potential to provide highly targeted treatment, especially to microscopic tumour cells. Targets include leukemias, lymphomas, gliomas, melanoma, and peritoneal carcinomatosis. As in diagnostic nuclear medicine, appropriate radionuclides can be chemically bound to a targeting biomolecule which carries the combined radiopharmaceutical to a specific treatment point.

<span class="mw-page-title-main">Charles Pecher</span>

Charles Pecher was a Belgian pioneer in nuclear medicine. He discovered and introduced strontium-89 in medical therapeutic procedures in 1939.

References

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  2. 1 2 Suominen, Mari I.; Wilson, Timothy; Käkönen, Sanna-Maria; Scholz, Arne (10 August 2019). "The Mode-of-Action of Targeted Alpha Therapy Radium-223 as an Enabler for Novel Combinations to Treat Patients with Bone Metastasis". International Journal of Molecular Sciences. 20 (16): 3899. doi: 10.3390/ijms20163899 . PMC   6720648 . PMID   31405099.
  3. Vidaud, Claude; Miccoli, Laurent; Brulfert, Florian; Aupiais, Jean (26 November 2019). "Fetuin exhibits a strong affinity for plutonium and may facilitate its accumulation in the skeleton". Scientific Reports. 9 (1): 17584. Bibcode:2019NatSR...917584V. doi:10.1038/s41598-019-53770-6. PMC   6879641 . PMID   31772265.
  4. Marques, I.A.; Neves, A.R.; Abrantes, A.M.; Pires, A.S.; Tavares-da-Silva, E.; Figueiredo, A.; Botelho, M.F. (July 2018). "Targeted alpha therapy using Radium-223: From physics to biological effects". Cancer Treatment Reviews. 68: 47–54. doi:10.1016/j.ctrv.2018.05.011. PMID   29859504.
  5. Ozgur, S; Sumer, H; Kocoglu, G (1 December 1996). "Rickets and soil strontium". Archives of Disease in Childhood. 75 (6): 524–526. doi:10.1136/adc.75.6.524. PMC   1511822 . PMID   9014608.
  6. RELEVANCE TO PUBLIC HEALTH. Agency for Toxic Substances and Disease Registry (US). April 2004. Retrieved 8 April 2024.
  7. Blake, Glen M; Fogelman, Ignac (December 2006). "Strontium ranelate: a novel treatment for postmenopausal osteoporosis: a review of safety and efficacy". Clinical Interventions in Aging. 1 (4): 367–375. doi: 10.2147/ciia.2006.1.4.367 . PMC   2699648 . PMID   18046914.
  8. Rotman, Stijn G.; Thompson, Keith; Grijpma, Dirk W.; Richards, Robert G.; Moriarty, Thomas F.; Eglin, David; Guillaume, Olivier (March 2020). "Development of bone seeker–functionalised microspheres as a targeted local antibiotic delivery system for bone infections". Journal of Orthopaedic Translation. 21: 136–145. doi:10.1016/j.jot.2019.07.006. PMID   32309139.