Abstract: An improved bio-osmotic gel for filling implant lumens consisting substantially of an amount of a bio-compatible organic polymer and a solution of bio-compatible salt is disclosed which exhibits osmotic qualitites closely paralleling that of human body serum and improved radiolucency with respect to silicone oil and saline. The bio-osmotic gel can contain a polymer having the empirical formula [(CHCH.sub.2).sub.2 N(CH.sub.2).sub.3 CO].sub.n i.e. polyvinylpyrrollidone. The bio-compatible salt can be made of a low Z value salt such as sodium bicarbonate, sodium acetate, or sodium lactate. The gel material should have an osmolarity between 250 and 350 milliosmoles and have an X-ray absorption under standard exposure approximately equal to that of breast tissue such that processed mammographic X-ray film will have an optical density of 1.2 to 1.3 and an average penetrance of between 9.2 and 30.0 milliroentgens.

Abstract: Capsular contracture causing firmness of soft silicone implants is a serious problem that may result from several causative factors that have as their final pathway, the development of increased scar tissue. The present invention has altered the formation of this scar encapsulation of silicone implants by texturing the silicone surface in order to gain fibroblast ingrowth into the interstices and thus prevent micromotion at the host prosthesis interface. It has been found that this produces a thinner fibrous capsule. Previously published work pertaining to animals and man has shown that similar texturing of tetrafluoroethylene (Teflon) and other substances achieves these goals. In accordance with work leading up to the present invention, textured silicone samples have been implanted in the subcutaneous layer of rabbits, the capsule formation and the host-prosthesis interface studied histologically.