Proliferation of myocytes on different ECM-components of animal/human origin in vitro

Three-dimensional direct writing of B35 neuronal cells

We have demonstrated two-dimensional and three-dimensional transfer of B35 neuronal cells onto and within polymerized Matrigel substrates, using matrix-assisted pulsed laser evaporation-direct write (MDW). The B35 cells were transferred from a quartz ribbon to depths of up to 75 microm by systematically varying the fluence emitted from the ArF (lambda = 193 nm) laser source. MDW-transferred cells were examined using terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL), 4',6-diamidino-2-phenylindole (DAPI), and alpha-tubulin staining. Confocal microscopy has shown that the transferred B35 cells extended their axons outward in three dimensions within the polymerized Matrigel substrate. The B35 cells made axonal connections and formed a three-dimensional neural network within 72 h after MDW transfer. In addition, TUNEL staining demonstrated that only 3% of the B35 cells underwent apoptosis after being transferred using the MDW process. MDW and other emergent direct write processes may provide unique approaches for creating layered, heterogeneous, three-dimensional cell-seeded scaffolds for use in peripheral nerve repair.

Autologous Bone Marrow-Derived Cells Enhance Muscle Strength Following Skeletal Muscle Crush Injury in Rats

Insufficient post-traumatic skeletal muscle regeneration with consecutive functional deficiency continues to be a serious problem in orthopedic and trauma surgery. Transplantation of autologous muscle precursor cells has shown encouraging results in muscle trauma treatment but is associated with significant donor site morbidity. In contrast to this, bone marrow-derived (BMD) cells can be obtained without any functional deficit by puncture. The goal of this study was to examine whether regular muscle regeneration can be improved by local application of autologous BMD cells in a rat model of blunt skeletal muscle trauma. One week after standardized open blunt crush injury to the left soleus muscle, 10(6) autologous BMD cells were injected into the traumatized muscle of male Sprague Dawley rats. Rats of the control group received saline solution as treatment. Three weeks after application, the fast twitch and tetanic contraction capacity of the soleus muscles was measured bilaterally by stimulating the sciatic nerves. Contraction forces of injured soleus muscles in control animals recovered to 39 +/- 10% (tetanic) and 59 +/- 12% (fast twitch) of the contralateral noninjured soleus muscles (p < 0.001). In contrast, autologous BMD cell injection significantly restored contractile forces to 53 +/- 8% (tetanic) and 72 +/- 13% (fast twitch) compared to those observed in contralateral noninjured soleus muscles. Thus, muscle function was significantly increased by BMD cell treatment (tetanic, p = 0.014; fast twitch, p = 0.05). In conclusion, autologous BMD cell grafting leads to an increase in contraction force, 14% in tetanic and 13% in fast twitch stimulation, demonstrating its potential to improve functional outcome after skeletal muscle crush injury.