June 18, 2010

June 18, 2010 (Beijing, China) — Chinese researchers have successfully engineered myocardial tissue in vivo using a novel scaffold and cardiomyocytelike cells derived from bone-marrow mesenchymal stem cells (BMMSCs) [1]. The researchers also showed that the engineered myocardial tissue shares structural and functional similarities with native myocardial tissue.

"The structure of the transplanted engineered myocardial tissue was similar with native heart tissue in that it was positive for the cardiomyocyte-specific protein troponin I and had a natural structure similar to native tissue with the presence of gap junctions and desomosomes, which are needed for tissue conduction," lead investigator Dr Lv An-Lin (Xijing Hospital of the Fourth Military Medical University, Xi'an, China) told heartwire .

Drs Lv An-Lin, Xing Yu-Jie, and Wang Li

Presenting the results of their study, performed in laboratory rats, here at the World Congress of Cardiology 2010, An-Lin said the purpose of the study was to construct engineered myocardial tissue using polylactic-co-glycolic acid (PLGA) for the scaffold and seed the BMMSCs on the scaffold prior to implantation. PLGA was selected as the scaffold because it was believed to work better in vivo than natural materials such as collagen, fibrin glue, or coralline. Over an eight-week period, the researchers cultured the BMMSCs and then seeded the cells into the PLGA scaffolds. These "constructs" were then incubated and implanted in the peritoneal cavity of the laboratory rats.

Immunohistochemical staining revealed the cardiomyocytelike cells were positive for troponin I, and scanning with electron microscopy showed that the cells attached to the PLGA scaffold developed an extensive extracellular matrix, which is needed for cell growth. Scanning with transmission electron microscopy revealed the presence of gap junctions and desomosomes.

Speaking with heartwire , An-Lin said that while this type of research is still in its infancy, the data suggest that researchers might be able to generate cardiomyocytes that share functional and structural similarities with native heart tissue, and this would be promising in the repair of damaged heart muscle.

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