Bone seeker

Last updated

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, such as in the case of radium-223. [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

<span class="mw-page-title-main">Osteoporosis</span> Skeletal disorder

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.

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

Rickets, scientific nomenclature: rachitis, 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.

Radionuclide therapy uses radioactive substances called radiopharmaceuticals to treat medical conditions, particularly cancer. These are introduced into the body by various means and localise to specific locations, organs or tissues depending on their properties and administration routes. This includes anything from a simple compound such as sodium iodide that locates to the thyroid via trapping the iodide ion, to complex biopharmaceuticals such as recombinant antibodies which are attached to radionuclides and seek out specific antigens on cell surfaces.

<span class="mw-page-title-main">Osteomalacia</span> Softening of bones due to impaired bone metabolism

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.

<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">Calcitriol</span> Active form of vitamin D

Calcitriol is a hormone and the active form of vitamin D, normally made in the kidney. It is also known as 1,25-dihydroxycholecalciferol. It 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 mainly by increasing the uptake of calcium from the intestines.

<span class="mw-page-title-main">Osteopenia</span> Abnormally low bone mineral density

Osteopenia, known as "low bone mass" or "low bone density", is a condition in which bone mineral density is low. Because their bones are weaker, people with osteopenia may have a higher risk of fractures, and some people may go on to develop osteoporosis. In 2010, 43 million older adults in the US had osteopenia. Unlike osteoporosis, osteopenia does not usually cause symptoms, and losing bone density in itself does not cause pain.

Renal osteodystrophy is currently defined as an alteration of bone morphology in patients with chronic kidney disease (CKD). It is one measure of the skeletal component of the systemic disorder of chronic kidney disease-mineral and bone disorder (CKD-MBD). The term "renal osteodystrophy" was coined in 1943, 60 years after an association was identified between bone disease and kidney failure.

<span class="mw-page-title-main">Hypophosphatasia</span> Metabolic bone disease

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> Breakdown of bone tissue to be absorbed into the blood

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">X-linked hypophosphatemia</span> X-linked dominant disorder that causes rickets

X-linked hypophosphatemia (XLH) is an X-linked dominant form of rickets that differs from most cases of dietary deficiency rickets in that vitamin D supplementation does not cure it. It can cause bone deformity including short stature and genu varum (bow-leggedness). It is associated with a mutation in the PHEX gene sequence (Xp.22) and subsequent inactivity of the PHEX protein. PHEX mutations lead to an elevated circulating (systemic) level of the hormone FGF23 which results in renal phosphate wasting, and local elevations of the mineralization/calcification-inhibiting protein osteopontin in the extracellular matrix of bones and teeth. An inactivating mutation in the PHEX gene results in an increase in systemic circulating FGF23, and a decrease in the enzymatic activity of the PHEX enzyme which normally removes (degrades) mineralization-inhibiting osteopontin protein; in XLH, the decreased PHEX enzyme activity leads to an accumulation of inhibitory osteopontin locally in bones and teeth to block mineralization which, along with renal phosphate wasting, both cause osteomalacia and odontomalacia.

<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.

<span class="mw-page-title-main">Vitamin D deficiency</span> Human disorder

Vitamin D deficiency or hypovitaminosis D is a vitamin D level that is below normal. It most commonly occurs in people when they have inadequate exposure to sunlight, particularly sunlight with adequate ultraviolet B rays (UVB). Vitamin D deficiency can also be caused by inadequate nutritional intake of vitamin D; disorders that limit vitamin D absorption; and disorders that impair the conversion of vitamin D to active metabolites, including certain liver, kidney, and hereditary disorders. Deficiency impairs bone mineralization, leading to bone-softening diseases, such as rickets in children. It can also worsen osteomalacia and osteoporosis in adults, increasing the risk of bone fractures. Muscle weakness is also a common symptom of vitamin D deficiency, further increasing the risk of fall and bone fractures in adults. Vitamin D deficiency is associated with the development of schizophrenia.

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">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

  1. "Radionuclide Basics: Strontium-90". www.epa.gov. 15 April 2015. Retrieved 8 April 2024.
  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. PMC   7152806 . PMID   32309139.