Liver regeneration using decellularized splenic scaffold: a novel approach in tissue engineering

BACKGROUND： The potential application of decellularized liver scaffold for liver regeneration is limited by severe shortage of donor organs. Attempt of using heterograft scaffold is accompanied with high risks of zoonosis and immunological rejection. We proposed that the spleen, which procured more extensively than the liver, could be an ideal source of decellularized scaffold for liver regeneration. METHODS： After harvested from donor rat, the spleen was processed by 12-hour freezing/thawing ×2 cycles, then circulation perfusion of 0.02% trypsin and 3% Triton X-100 sequentially through the splenic artery for 32 hours in total to prepare decellularized scaffold. The structure and component characteristics of the scaffold were determined by hematoxylin and eosin and immumohistochemical staining, scanning electron microscope, DNA detection, porosity measurement, biocompatibility and cytocompatibility test. Recellularization of scaffold by 5×106 bone marrow mesenchymal stem cells（BMSCs） was carried out to preliminarily evaluate the feasibility of liver regeneration by BMSCs reseeding and differentiation in decellularized splenic scaffold.RESULTS： After decellularization, a translucent scaffold, which retained the gross shape of the spleen, was generated. Histological evaluation and residual DNA quantitation revealed the remaining of extracellular matrix without nucleus and cytoplasm residue. Immunohistochemical study proved the existence of collagens I, IV, fibronectin, laminin and elastin in decellularized splenic scaffold, which showed a similarity with decellularized liver. A scanning electron microscope presented the remaining three-dimensional porous structure of extracellular matrix and small blood vessels. The poros-ity of scaffold, aperture of 45.36±4.87 μm and pore rate of 80.14%±2.99% was suitable for cell engraftment. Subcutaneous implantation of decellularized scaffold presented good histocompatibility, and recellularization of the splenic scaffold demonstrated that BMSCs could locate and survive in the decellularized matrix. CONCLUSION： Considering the more extensive organ source and satisfying biocompatibility, the present study indicated that the three-dimensional decellularized splenic scaffold might have considerable potential for liver regeneration when combined with BMSCs reseeding and differentiation.

Study on the effect of moxibustion at “Shénquè”(神阙 CV 8) on the immune system of rats taking long-term exhaustive exercise

Objective To explore the effect of moxibustion at ＂Shénquè＂（神阙 CV 8） on the immune system of rats taking long-term exhaustive exercise.Method Thirty male SD rats were randomly divided into blank group,model group and moxibustion group with 10 rats in each group.Except the rats in blank group,all the rats were established into long-term exhaustive models through swimming again and again.Mild moxibustion at CV 8 for 15 min was carried out in the rats in moxibustion group after modeling.The treatment was conducted once every other day,and treatment for 10 times was needed.The exhaustive duration for each time was recorded,the levels of serum Ig A,Ig G,Ig M and ACP were detected 24 h after the 10 th exhaustive exercise,and the histomorphological changes of spleen were observed.Immunoturbidimetry was adopted for detecting the Ig A level,and ELISA method was used for detecting the levels of Ig G,Ig M and ACP.Results The common exhaustive duration in moxibustion group was longer than that in model group,however,the time difference was statistically significant after the 5th exhaustive exercise（P0.01）.The levels of serum IgG and IgM in model group were lower than that in blank group（all P0.01）,and the serum ACP level in model group was higher than that in blank group（P0.01）,indicating that the splenic histomorphology was damaged.The levels of serum Ig G and Ig M in moxibustion group were higher than that in model group（all P0.01）,and the serum ACP level in moxibustion group was lower than that in model group,showing that the splenic histomorphology was repaired.Conclusion Moxibustion at CV 8 can improve the levels of immunoglobulin（Ig G,Ig A,Ig M） of tired body for a long time,decrease the ACP level,and repair the damaged spleen tissues.