Biological tolerance of ionogenic hydrophilic gels

Abstract

AbstractThe long‐term biological tolerance of hydrophilic gels containing ionogenic groups was investigated on animals (rats and pigs). The basic polymeric skeletons of poly(glyco1 monomethacrylate) and poly (N‐ethyl methacrylamide) were modified by introducing acidic (carboxylic) and basic (tert‐amino) groups, or both groups at a time. Introduction of both groups at a time in the molar ratio yielded an electroneutral polymer of ionogenic character.In all groups investigated here the implant was encapsulated by a fine capsule of collagen fibrous tissue; no signs of proliferation were observed. No calcification took place.The second part of the work consisted in an investigation of the tolerance of heterogeneous poly(glyco1 monomethacrylate) gels containing ionogenic groups,basic, acidic, and ampholytic, with continuously changing porosity. The microporous polymers (50–60% water in the starting mixture) were healed‐in as compact gels by encapsulation with collagen fibrous tissue. The macroporous polymers (70% of water and more in the starting mixture) were encapsulated with a capsule of collagen fibrous tissue, from which newly formed capillaries,serous exudate and numerous cells penetrated into the implant. The more porous the material, the broader the zone of cellulization. In microporous polymers there was no calcification; in macroporous, calcification occurred in the margin of the implant or in its center. In contrast with other authors' findings,no effect of the chemical composition within the concentration range investigated upon the way of healing‐in or calcification could be observed; only the effect of physical factors was evident.