Biomaterial-microvasculature interaction on polymers after implantation in mice.

Biomaterial research is expected to forward new materials to be used as, e.g., implant materials or as scaffolds for tissue engineering. It is central for such a scaffold material to create the track on which those cells can inhabitate the scaffold needed to rebuild functional tissue substitutes. For the biointegration of the implant with the native cellular tissue this must be able to grow on the material surface. For the elimination of the degradation products and the adeqaute transport of nutrients/gases within the newly formed tissue the angiogenesis of new blood vessels is thought to play an important role. In the present study, a new biomaterial, a non-porous polymeric AB-network based on oligo (epsilon-hydroxycaproat) and oligobutylacrylat, was implanted in animals. Male NMRI mice were implanted subcutaneously for one week to nine weeks. Immediately after the explantation, the probes were examined histologically. Already one week after implantation, there was a strong tissue-integration of the polymer. Importantly, blood vessels appeared at the polymer surface. At nine weeks after implantation the tissue integration was stronger than after one week and blood vessels were still observed in the periimplant tissue. The mechanism of the early integration of the polymer is not clear. The relationship between the new periimplant vessels and the integration of the polymer has to be studied.

Angiogenesis around new AB-polymer networks after one week of implantation in mice.

Biomaterials research is expected to forward new materials to be used as, e.g., implant materials or as scaffolds for tissue engineering. It is central for such a scaffold material to create the track on which those cells can inhabit the scaffold needed to rebuild functional tissue substitutes. The tissue engineering concept expects a gradual gain in functionality of the newly created tissues while the scaffold materials are degraded and subsequently eliminated. Not only for the elimination of the degradation products the angiogenesis of new blood vessels is thought to play an important role. In the present study, a new biomaterial, a non-porous polymeric AB-network based on oligo (epsilon-hydroxycaproate) and oligobutylacrylate, was implanted in animals. Male NMRI mice were implanted subcutaneously for one week. Immediately after the explantation, the probes were examined histologically. Already one week after implantation, there was a strong tissue-integration of the polymer. Importantly, blood vessels occurred at the polymer surface. There were also clusters of cells around the vessels, which were phenotypically similar to fat cells. The mechanism of the early integration of the polymer is not clear. The relationship between the new periimplant vessels and the integration of the polymer has to be studied.