Poly body reaction

Bergsina, EJ, Rozema, F.R., Bos, R.R.M., de Bruijn, W.C. (1993) Foreign body reactions to resorbable poly(l-lactide) bone plates and screws used for the fixation of unstable zygomatic fractures. /. Oral Maxillofacial Surg., 51, 666-670. 

The medical grade silicone rubber Sylgard 184 consists of a crosslinked poly-dimethylsiloxane. In vitro and in vivo testing has proven the non-cytotoxicity in direct and indirect contact. There is no ocular toxicity and no acute foreign body reaction in contact with soft tissues. 

Currently, application opportunities for poly()5-hydroxybutyrates) (PHB) - a member of the polyhydroxy alkanoate group - are being explored. Only very mild body reactions were detected with PHB implants during an implantation time of 12 months, there were no indications of chronic inflammation reactions. Enzymes accelerate hydrolytic degradation of PHB [954]. 

Biocompatibility studies of CFR-UHMWPE conducted during the 1970s also determined its response to be satisfactory [14]. Poly II was found by Groth et al. to be free of any significant foreign body reactions after clinical implantation of 12 to 15 months [15]. Rushton and Rae investigated the intra-articular response to particulate Poly II in mice and found it to be similar to that of neat UHMWPE [16]. 

In order to be successful as part of a medical device a polymer has to resist both biological rejection by the patient s body and degradation. The human body is an enviromnent which is simultaneously hostile and sensitive, so that materials for application in medicine must be carefully selected. The essential requirement is that these materials are biocompafible with the particular part of the body in which they are placed. The extent to which polymers fulfil this requirement of biocompafibility depends partly on the properties of the polymer and partly on the location in which they are expected to perform. For example the requirements for blood biocompafibility are stringent since blood coagulation may be triggered by a variety of materials. By contrast, the requirements for materials to be used in replacement joints in orthopaedic surgery are less severe and materials as diverse as poly (methyl methacrylate) and stainless steel can be used with minimal adverse reaction from the body. 

Multinuclear NMR spectroscopy is being used increasingly to study catalytic reactions. In order for such studies to be possible, all contact betv een the sample solutions and the metal part of the cell body has to be avoided because of possible catalytic effects. All materials in contact vith the sample solution have to be chemically inert and nonmetallic quartz, glass, PTFE, Vespel (polyimide polymer, Dupont de Nemours), PCTFE (poly-chlorotrifluoroethylene), Viton seals, etc. 

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