ObjectiveTo prepare a composite scaffold using bladder acellular matrix (BACM) and polyurethane (PU) for bladder repair and regeneration, and to evaluate its mechanical properties and biocompatibility. MethodsFresh bladder tissues were obtained from New Zealand rabbits and then treated with 1%SDS and 1%Triton X-100 to obtain BACM. The BACM was combined with PU to fabricate PU-BACM composite scaffold. The tensile strength and elongation at break of BACM and PU-BACM scaffolds were tested. Scaffolds and extracts of scaffolds were prepared to evaluate the biocompatibility. For cell-proliferation analysis, cell counting kit 8 method was used at 1, 3, 5, and 7 days after co-culture of human bladder smooth muscle cell (HBSMC) and scaffolds. The cell cycle was tested by flow cytometry after HBSMC co-cultured with extracts of scaffolds and DMEM culture medium (control group) for 24 hours. Finally, 12 New Zealand rabbits were used to establish the model of bladder repair and regeneration. Incision of 5 mm was made on the bladder, and PU-BACM scaffold was sutured with the incision. The rabbits were sacrificed at 10, 20, 40, and 60 days after surgery to observe the inflammatory cell infiltration, new tissues formation, and regeneration of epithelium by HE staining. ResultsThe tensile strength of BACM and PU-BACM composite scaffold was (5.78 ± 0.85) N and (11.88 ± 3.21) N, and elongation at break was 14.46%±3.21% and 23.14%±1.32% respectively, all showing significant diffeence (t=3.182, P=0.034；t=4.332, P=0.012). The cell-proliferation rates of controls, PU, BACM, and PU-BACM were 36.78%±1.21%, 30.49%±0.89%, 18.92%±0.84%, and 22.42%±1.55%, it was significantly higher in PU-BACM than BACM (P<0.05). In the bladder repair and regeneration experiment, inflammatory cell infiltration was observed at 10 days after operation, and reduced at 20 days after implantation. In the meanwhile, the degradation of scaffolds was observed in vivo. The regeneration of epithelium could be observed after 40 days of implantation. At 60 days after implantation, in situ bladder tissue formed. ConclusionPU-BACM composite scaffold has higher mechanical properties and better biocompatibility than BACM scaffold. PU-BACM composite scaffold will not lead to strong immune response, and new bladder tissue can form in the in vivo rabbit bladder repair experiment. These results can provide research basis and theoretical data for further study.
We applied resting-state functional magnetic resonance imaging (rfMRI) combined with graph theory to analyze 90 regions of the infantile small world neural network of the whole brain. We tried to get the following two points clear:① whether the parameters of the node property of the infantile small world neural network are correlated with the level of infantile intelligence development; ② whether the parameters of the infantile small world neural network are correlated with the children's baseline parameters, i.e., the demographic parameters such as gender, age, parents' education level, etc. Twelve cases of healthy infants were included in the investigation (9 males and 3 females with the average age of 33.42±8.42 months.) We then evaluated the level of infantile intelligence of all the cases and graded by Gesell Development Scale Test. We used a Siemens 3.0T Trio imaging system to perform resting-state (rs) EPI scans, and collected the BOLD functional Magnetic Resonance Imaging (fMRI) data. We performed the data processing with Statistical Parametric Mapping 5(SPM5) based on Matlab environment. Furthermore, we got the attributes of the whole brain small world and node attributes of 90 encephalic regions of templates of Anatomatic Automatic Labeling (ALL). At last, we carried out correlation study between the above-mentioned attitudes, intelligence scale parameters and demographic data. The results showed that many node attributes of small world neural network were closely correlated with intelligence scale parameters. Betweeness was mainly centered in thalamus, superior frontal gyrus, and occipital lobe (negative correlation). The r value of superior occipital gyrus associated with the individual and social intelligent scale was -0.729 (P=0.007); degree was mainly centered in amygdaloid nucleus, superior frontal gyrus, and inferior parietal gyrus (positive correlation). The r value of inferior parietal gyrus associated with the gross motor intelligent scale was 0.725 (P=0.008); efficiency was mainly centered in inferior frontal gyrus, inferior parietal gyrus, and insular lobe (positive correlation). The r value of inferior parietal gyrus associated with the language intelligent scale was 0.738 (P=0.006); Anoda cluster coefficient (anodalCp) was centered in frontal lobe, inferior parietal gyrus, and paracentral lobule (positive correlation); Node shortest path length (nlp) was centered in frontal lobe, inferior parietal gyrus, and insular lobe. The distribution of the encephalic regions in the left and right brain was different. However, no statistical significance was found between the correlation of monolithic attributes of small world and intelligence scale. The encephalic regions, in which node attributes of small world were related to other demographic indices, were mainly centered in temporal lobe, cuneus, cingulated gyrus, angular gyrus, and paracentral lobule areas. Most of them belong to the default mode network (DMN). The node attributes of small world neural network are widely related to infantile intelligence level, moreover the distribution is characteristic in different encephalic regions. The distribution of dominant encephalic is in accordance the related functions. The existing correlations reflect the ever changing small world nervous network during infantile development.