Injectable fibrin scaffold improves cell transplant survival, reduces infarct expansion, and induces neovasculature formation in ischemic myocardium
Karen L. Christman, BS*,
Andrew J. Vardanian, MS ,
Qizhi Fang, MD ,
Richard E. Sievers, BS,
Hubert H. Fok, MD and
Randall J. Lee, MD, PhD*,*
* University of California Berkeley and San Francisco Joint Bioengineering Graduate Group, University of California San Francisco, San Francisco, California, USA
Department of Medicine, University of California San Francisco, San Francisco, California, USA
Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, USA
View larger version (64K):
[in a new window]
|
Figure 1 Transplant myoblasts. (A) Phase contrast images. (B) Desmin-labeled cells. (C) Hoechst 33342-labeled nuclei. Transplant rat myoblasts (bottom panel) were stained with desmin and hoechst to verify myoblast percentage. Desmin staining indicates that cultured cell populations, which were subsequently injected into the myocardium, contained >95% myoblasts. One contaminating fibroblast is indicated by the arrows. Control rat fibroblasts and rat myoblasts from the L6 cell line were stained with desmin and hoechst as negative and positive controls, respectively.
|
|
View larger version (146K):
[in a new window]
|
Figure 2 Myoblast survival in fibrin glue in vitro (x4). (A) Surviving myoblasts after three days in culture in fibrin glue. (B) Surviving myoblasts after seven days in culture in fibrin glue. (C) Dead myoblasts after three days in culture in fibrin glue. (D) Dead myoblasts after seven days in culture in fibrin glue. Note the small amount of death as a result of the surrounding matrix.
|
|
View larger version (135K):
[in a new window]
|
Figure 3 Myoblast in fibrin glue 24 h after injection. (A) 4',6-diamidino-2-phenylindole-labeled myoblasts (x4) injected in fibrin glue are found in the infarct wall. (B) Corresponding hematoxylin and eosin stained section (x4). Transplanted myoblasts are surrounded by fibrin glue within the infarct scar. (C) Higher-magnification hematoxylin and eosin section (x10) displaying transplanted myoblasts in fibrin glue. (D) Hematoxylin and eosin stained section (x10) of fibrin glue ex vivo.
|
|
View larger version (164K):
[in a new window]
|
Figure 4 Myoblast survival and location within myocardium after five weeks (x100). (A and B) Anti-skeletal, fast myosin heavy chain-labeled myoblasts visualized with a Cy3 secondary antibody. (C and D) Hematoxylin and eosin-stained sections that neighbor (A) and (B), respectively. (C and D) Normal and infarcted myocardium are labeled to visualize the location of transplanted cells. (A) Transplanted skeletal myoblasts in bovine serum albumin are located at the border of the infarct scar. (B) In contrast, a greater number of skeletal myoblasts injected in fibrin glue are located both at the border and within the infarct scar. Surviving myoblasts are in clumps surrounding arterioles (arrows in B and D) in the scar.
|
|
View larger version (14K):
[in a new window]
|
Figure 5 Infarct size. The injection of fibrin glue and skeletal myoblasts resulted in statistically smaller infarcts than injection of bovine serum albumin (BSA). In contrast, the infarct size of hearts injected with skeletal myoblasts in BSA was not statistically different from hearts injected with BSA. *p < 0.05 compared with BSA (fibrin, p = 0.03; myoblasts in fibrin, p = 0.003). LV = left ventricle.
|
|
View larger version (90K):
[in a new window]
|
Figure 6 Fibrin-induced arteriole formation (x100). (A) Anti-smooth muscle actin-labeled arterioles visualized with a Cy3 secondary antibody. (B) Hematoxylin and eosin stained section that neighbors (A). (B) Normal, healthy myocardium is denoted by the darker staining whereas the infarct scar has lighter staining. (A and B) Fibrin induces the formation of several arterioles within the infarct.
|
|
|
