Expression of genes for bone morphogenetic proteins and receptors in human dental pulp.

Bone morphogenetic proteins (BMP) have been shown to induce reparative dentine formation experimentally but the cells responsible, which respond to BMPs, have not been identified. The BMP signal is probably mediated by interaction of type I and II BMP receptors (R). Here, the RNA of human adult dental pulp and pulp cells in culture was examined by reverse transcription (RT) polymerase chain reaction (PCR) for evidence of mRNA for BMPs.

A micromachined silicon sieve electrode for nerve regeneration applications.

A micromachined silicon sieve electrode has been developed and fabricated to record from and stimulate axons/fibers of the peripheral nervous system by utilizing the nerve regeneration principle. The electrode consists of a 15-microns-thick silicon support rim, a 4-microns-thick diaphragm containing different size holes to allow nerve regeneration, thin-film iridium recording/stimulating sites, and an integrated silicon ribbon cable, all fabricated using boron etch-step and silicon micromachining techniques. The thin diaphragm is patterned using reactive ion etching to obtain different size holes with diameters as small as 1 micron and center-center spacings as small as 10 microns.

Functional regeneration of glossopharyngeal nerve through micromachined sieve electrode arrays.

To assess the potential of micromachined silicon sieve electrodes for long term recordings from single afferent sensory fibers, we implanted them between the cut ends of rat glossopharyngeal nerves which innervate taste and somatosensory receptors on the posterior tongue. After the implants had been in place for an average of 101 days nerve regeneration was measured using histological and electrophysiological methods. Axons of the glossopharyngeal nerve regenerated through holes in the sieves and supported the functional regeneration of taste, thermal and mechanoreceptors.