An amino functional group was substituted on a PET film surface for the purpose of making the implantation of collagen readily. The PET has been widely used for medical materials such as an artificial ligament because of its strength and antibacterial action. However, when transplanted in human bodies, its compatibility is not good enough to adapt to the collagen which grows from living body tissues. To avoid this reaction medicine has been used clinically which makes the PET fiber into a mesh state and after the transplantation into a human body, makes the tissue intrude in the PET fiber. However, this method has not shown satisfactory enough results to promote rehabilitation. If the living body compatibility of materials is improved the initial adapting power with the tissue can be enhanced.
Then we substituted NH2, which has a high affinity for collagen, on the PET surface by ArF laser. PET is highly hydrophobic and does not dissolve well in aqueous solutions. To avoid this reaction we make a thin ammonium fluoride solution layer on the PET surface with capillary phenomenon. Then an ArF laser beam was irradiated vertically onto the sample. The result of this treatment shows that an untreated sample having the contact angle of 80° with water and the bonding strength of only 1.0 kg/cm2 with collagen was improved to have the contact angle of 22° and the bonding strength to be 12 kg/cm2.
When the treated sample had been implanted into the subcutaneous tissue of a rabbit's regiones dorsales, existence of leukocyte colonies that are indicators of human histocompatibility was confirmed on the hydrophilic parts of the sample.