Methacrylate polymers bone cements

Vallo Cl, Montemartini PE, Cuadrado TR. Effect of residual monomer content on some properties of a poly(methyl methacrylate)-based bone cement. J Appl Polym Sci 1998 69 ... 

P.M. Chou and M. Mariatti, The properties of polymethyl methacrylate (PMMA) bone cement filled with titania and hydroxyapatite fillers. Polym. Blast. Technol. Eng.49 1163-1171,2010. 

We chose to modify the anhydride monomers with photopolymerizable methacrylate functionalities. Methacrylate-based polymers have a long history in biomedical applications, ranging from photocured dental composites [20] to thermally cured bone cements [21]. Furthermore, photopolymerizations provide many advantages for material handling and processing, including spatial and temporal control of the polymerization and rapid rates at ambient temperatures. Liquid or putty-like monomer/initiator... 

The use of such an ethylene/acrylate copolymer provides a number of advantages. The ethylene portion of the copolymer is particularly well suited for adhering to the PE of the first polymer layer during fusion of the first polymer layer and the second polymer layer to one another. Further, the acrylate portion of the copolymer is particularly well suited for adhesion to bone cement, such as bone cement that includes poly(methyl methacrylate). Thus, using such a copolymer in the construction provides for ease of implantation in regard to a bearing designed for cement fixation. 

KORAD LPT LUCITE METAPLEX NO METHACRYLIC ACID METHYL ESTER POLYMERS METHYL METHACRYLATE HOMOPOLYMER METHYL METH.ACRYLATE POLYMER METHYL METHACRYLATE RESIN 2-METHYL-2-PROPENOIC ACID METHYL ESTER HOMOPOLYMER ORGANIC GLASS E 2 OSTEOBOND SURGICAL BONE CEMENT... 

PMMA bone cement, primarily used in hip and knee replacement surgery, remains an important use of PMMA polymer in medicine. The bone cement consists of PMMA (polymer) and methyl methacrylate monomer that is mixed with initiator at the time of surgery. The dough-like mixture is inserted into a... 

In this class of amorphous polymers, there are many biomedical polymers such as phenolic resins (adopted for production of surgical instruments), unsaturated polyester resins (used in bone repair) (Kharas et al., 1997), polystyrene (e.g. Petri dishes for cell culture) and polymethyl methacrylate (PMMA, used in bone cements, intraocular lens, and dental fillings) (Stuart, 2002). These are highly crosslinked polymers (resins in particular) or linear thermoplastic polymers that do not show structural macromolecular regularity. 

Medicine. For years, dentures, dental fillings, and denture bases have been made using methacrylic ester polymers (129,130) (see DENTAL Materials). These polymers can also be used to prevent tooth decay in natural teeth by serving as a barrier which can be coated over the surface of the tooth. The dimensional behavior of these bone-cement composites has been reported (131) as has the structure of the cold-cured acrylic resin (132). Both hard and soft contact lenses have been made using polymethacrylates (133,134). hHYDROGELS (qv) comprising poly(2-hydroxyethyl methacrylate) are used in soft contact lenses (135,136). 

PolyCmethyl methacrylate) (PMMA) and its derivatives are the most commonly used polymers in bone cements for the fixation in orthopaedic surgeries. PMMA is an amorphous thermoplastic polymer that offers excellent optical clarity, resistance... 

Nowadays, commercially available acrylic bone cements are sold in a kit of two components, a solid phase (polymer powder with initiator) and a liquid ampoule containing the methyl methacrylate (MMA) and a tertiaryamine. This is based on the fact that polymerization of PMMA can also be initiated by oxidation-reduction reactions. An advantage of a redox initiator is that the radical production starts at lower temperatures in comparison to the traditional initiators, where a high temperature is necessary to generate the radical initiator. Generally, the most used combination includes benzoyl peroxide and NdV-dimethylaniline. The proposed initiation mechanism is shown in Figure 12.9. 

Bone cements are, traditionally, injectable systems based on acrylic polymers. They are constituted by a solid and a liquid component that harden after mixing due to the polymerization of acrylic monomers in the liquid. Just some minutes after mixing, the paste attains high viscosity and must then be injected into the bone cavity, where the final stages of polymerization will take place. The solid is in most cases constituted by poly(methyl methacrylate) (PMMA) powder (or a copolymer of MMA with others monomers), benzoyl peroxide (BPO, the initiator of the polymerization), and a radio-opacifier, while the liquid is formed by MMA monomer (in some cases with n-butyl methacrylate, BuMA) and dimethyl-j -toluidine (DMT, the activator of the initiator). 

VaUo CL Residual monomer content in bone cements based on poly(methyl methacrylate). Polym ZfJt 2000 49 831-838. 

In describing the components of total joint prostheses and their interaction with adjacent tissues, many authors identify the articulating interface (metal/polymer), the metallic prosthesis - polymethylmethacrylate bone cement interface and the bone cement-bone interface. Unfortunately, the bone cement-bone interface may be transient with a fibrous capsule eventually interposing itself between the bone cement and the bone to create the bone cement-fibrous capsule-bone interface (19,20). As described earlier, the formation of a fibrous capsule around implants is a common occurrence. In the case of total joint prostheses where situ polymerizing methyl methacrylate is used as bone cement, this fibrous capsule formation may be accelerated by the heat of polymerization or the toxicity of the monomer, both of which may lead to localized tissue destruction and cell death (21,22). 

To end, we must emphasize that methacrylates in medicine are made use of in diverse areas including bone and dental cements (109), and as surface modifiers to prevent or delay process of rejection (110), and that each commands a formidable literature. The reader should also be aware of the considerable effort which has been directed towards a phenomenological and theoretical understanding of the solution and swelling properties of synthetic hydrogel and polyelectrolyte polymers (111-116). 

Most joint replacements utilize polymers to some extent. Finger joints usually are replaced with a poly(dimethylsiloxane) Insert and over h00,000 such replacements are made each year (l). More recently a poly(1, -hexadiene) polymer has been tried in this application (l). Many other parts of the hand, such as the bones, have also been replaced by silicone rubber. Other types of joints, such as the hip or the knee, often involve the contact of a metal ball or rider on a plastic surface which is usually made from high density, high molecular weight polyethylene. These metal and plastic parts are usually anchored in the body using a cement of poly(methyl methacrylate) which is polymerized in situ. Full and partial hip prostheses are implanted about... 

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