Methods for improving the bioactivity characteristics of a surface and objects with surfaces improved thereby

A method of improving bioactivity of a surface of an implantable object, the method comprising:

• forming an accelerated Neutral Beam in a reduced-pressure chamber including
• forming a gas-cluster ion-beam comprising ionized gas clusters in the reduced-pressure chamber,
• accelerating the gas-cluster ion-beam along a beam path,
• at least partially dissociating gas clusters in the gas-cluster ion-beam along the beam path by increasing the range of velocities of ions in the accelerated gas cluster ion beam wherein the neutral Beam is essentially free of intermediate size clusters,
• at least partially neutralizing the gas cluster ion-beam, and
• separating ionized particles from the at least partially neutralized gas-cluster ion-beam to form the accelerated Neutral Beam;
• introducing an object into the reduced-pressure chamber;
• wherein said object is selected from the group consisting of a medical prosthesis, a surgical implant, a component of a medical prosthesis, a component of a surgical implant, and other objects intended for implantation in a living mammal and further wherein at least a portion of the surface of the implantable object comprises a material selected from the group consisting of titania, titanium, an alloy of titanium, and polytetrafluoroethylene (PTFE);
• and
• irradiating at least a first portion of the surface of said object with the accelerated Neutral Beam.