Tissue injectable composition and method of use

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention consists of an injectable composition that is a combination of a plurality of small, smooth-surfaced particles that are carried in a lubricative fluid or gel that is preferably comprised of a biologically compatible, lubricous solution, suspension, other fluid or gel.
In a first embodiment, the particles comprise microbeads or microparticles of a hard, material serving as a substrate and having a thin coating or film of biocompatible, isotropic carbon deposited on their surfaces.
The substrate material is preferably radiopaque.
Different types of carbon coating processes may be utilized, with the particulate substrate being a substance selected for compatibility with the coating process.
As shown in the figure which is a depiction from actual photomicrographs of particles produced in accordance with the present invention, the substrate particles are completely encased by the thin coating.
This results in a smooth coated particle with no substrate exposure on the surface of the particle or in contact with tissue when injected.
Low temperature isotropic (LTI) pyrolytic carbon is a preferred carbon coating.
Pyrolytic derives from the term pyrolysis, which is a thermal decomposition of hydrocarbons to produce a carbon material.
Pyrolytic carbon is produced in a process in which hydrocarbons and alloying gases are decomposed in a fluidized or floating bed.
Inert gas flow is used to float the bed and the substrate particles.
The hydrocarbon pyrolysis results in high carbon, low hydrogen content spheres, which deposit as solids upon the substrate in the fluidized bed.
As they deposit at temperatures of 1200.
degree.
-1500.
degree.
C.
, the spheres may coalesce, deform or grow due to atom movement, resulting in a high density coating.
A hard, metallic or ceramic substance capable of withstanding the high temperature conditions of the coating process is the preferred substrate material.
Aluminum oxide is a preferred substrate material.
Zirconium oxide has also been found to be especially suitable as such a substrate