Editing Poly(methyl methacrylate) (section)

=== Medicine ===

* PMMA has a good degree of compatibility with human [[tissue (biology)|tissue]], and it is used in the manufacture of rigid [[intraocular lens]]es which are implanted in the [[human eye|eye]] when the original lens has been removed in the treatment of [[cataract]]s. This compatibility was discovered by the English ophthalmologist [[Harold Ridley (ophthalmologist)|Harold Ridley]] in WWII RAF pilots, whose eyes had been riddled with PMMA splinters coming from the side windows of their Supermarine [[Spitfire]] fighters – the plastic scarcely caused any rejection, compared to glass splinters coming from aircraft such as the [[Hawker Hurricane]].<ref>Robert A. Meyers, "Molecular biology and biotechnology: a comprehensive desk reference", Wiley-VCH, 1995, p. 722 {{ISBN|1-56081-925-1}}</ref> Ridley had a lens manufactured by the Rayner company (Brighton & Hove, East Sussex) made from Perspex polymerised by ICI. On 29 November 1949 at St Thomas' Hospital, London, Ridley implanted the first intraocular lens.<ref>{{cite book |last=Apple |first=David J |title=Sir Harold Ridely and His Fight for Sight: He Changed the World So That We May Better See It |year=2006 |publisher=Slack |location=Thorofare NJ USA |isbn=978-1-55642-786-2}}</ref>
In particular, acrylic-type lenses are useful for cataract surgery in patients that have recurrent ocular inflammation (uveitis), as acrylic material induces less inflammation.
* [[Glasses|Eyeglass]] lenses are commonly made from PMMA.
* Historically, hard [[contact lens]]es were frequently made of this material. Soft contact lenses are often made of a related polymer, where acrylate monomers containing one or more [[hydroxyl|hydroxyl group]]s make them [[hydrophile|hydrophilic]].
* In [[orthopedic surgery]], PMMA [[bone cement]] is used to affix implants and to remodel lost bone.<ref>{{Cite journal |last1=Carroll |first1=Gregory T. |last2=Kirschman |first2=David L. |date=2022-07-13 |title=A portable negative pressure unit reduces bone cement fumes in a simulated operating room |journal=Scientific Reports |language=en |volume=12 |issue=1 |page=11890 |doi=10.1038/s41598-022-16227-x |issn=2045-2322 |pmc=9279392 |pmid=35831355|bibcode=2022NatSR..1211890C }}</ref> It is supplied as a powder with liquid methyl methacrylate (MMA). Although PMMA is biologically compatible, MMA is considered to be an irritant and a possible [[carcinogen]]. PMMA has also been linked to [[cardiopulmonary resuscitation|cardiopulmonary]] events in the operating room due to [[hypotension]].<ref>{{cite journal |first1=Timothy J. |last1=Kaufmann |first2=Mary E. |last2=Jensen |first3=Gabriele |last3=Ford |first4=Lena L. |last4=Gill |first5=William F. |last5=Marx |first6=David F. |last6=Kallmes |title=Cardiovascular Effects of Polymethylmethacrylate Use in Percutaneous Vertebroplasty |journal=American Journal of Neuroradiology |pmid=11950651 |url=http://www.ajnr.org/cgi/pmidlookup?view=long&pmid=11950651 |date=2002-04-01 |volume=23 |issue=4 |pages=601–4 |pmc=7975098}}</ref> Bone cement acts like a [[grout]] and not so much like a glue in [[arthroplasty]]. Although sticky, it does not bond to either the bone or the implant; rather, it primarily fills the spaces between the prosthesis and the bone preventing motion. A disadvantage of this bone cement is that it heats up to {{Convert|82.5|C|F}} while setting that may cause thermal necrosis of neighboring tissue. A careful balance of initiators and monomers is needed to reduce the rate of polymerization, and thus the heat generated.
* In [[plastic surgery|cosmetic surgery]], tiny PMMA microspheres suspended in some biological fluid are injected as a soft-tissue filler under the skin to reduce wrinkles or scars permanently.<ref>{{cite web |title=Filling in Wrinkles Safely |url=https://www.fda.gov/ForConsumers/ConsumerUpdates/ucm049349.htm |publisher=U.S. Food and Drug Administration |access-date=8 December 2015 |date=February 28, 2015 |url-status=dead |archive-url=https://web.archive.org/web/20151121160450/https://www.fda.gov/ForConsumers/ConsumerUpdates/ucm049349.htm |archive-date=21 November 2015}}</ref> PMMA as a soft-tissue filler was widely used in the beginning of the century to restore volume in patients with HIV-related facial wasting. PMMA is used illegally to shape muscles by some [[bodybuilding|bodybuilders]].
* [[Plombage]] is an outdated treatment of [[tuberculosis]] where the [[pleural]] space around an infected [[lung]] was filled with PMMA balls, in order to compress and collapse the affected lung.
* Emerging biotechnology and [[medical research|biomedical research]] use PMMA to create [[microfluidics|microfluidic]] [[lab-on-a-chip]] devices, which require 100 micrometre-wide geometries for routing liquids. These small geometries are amenable to using PMMA in a [[biochip]] fabrication process and offers moderate [[biocompatibility]].
* [[Bioprocess]] [[chromatography]] columns use cast acrylic tubes as an alternative to glass and stainless steel. These are pressure rated and satisfy stringent requirements of materials for [[biocompatibility]], toxicity, and extractables.