D. Lím

Biological tolerance of poly(N-substituted methacrylamides)

The biological tolerance of poly(N-substituted acrylamides) implanted subcutaneously to rats and pigs was investigated. Besides a macro- and microscopical evaluation of the implant and its surroundings, the surface changes of the implants were determined by means of a Stereoscan electron-optical microscope;the results obtained confirmed the very good in vivo stability of the polymers used. The histological analysis showed that all the polymers under investigation are very well tolerated by the organism and do not provoke any unfavorable reaction. The implants become surrounded with a granulation tissue which is gradually replaced by fibrocytes and collagen fibers situated in the basic substance staining positively with the alcian blue and PAS. In contrast with some authors we did not find a thicker capsule surrounding the implant on the sharp edges but on the flat planes. No calcification could be observed within the intervals investigated. The surface changes, which were studied electronoptically, were insignificant and connected with the way in which the implant was treated. No indications of malignant growth were observed.