Figure 7d:

Photomicrographs demonstrate histopathologic analysis and hMSC retention in the heart. (a) H-E staining of the heart (original magnification, ×2) 1 week after x-ray/MR imaging–guided delivery of BaCaps with hMSCs (arrows). Insert shows viable hMSCs, with clear nuclear morphology and absence of a foreign-body reaction. Subjacent to the BaCaps is a moderate bed of fibroplasia and capillaries. (b) H-E staining of the heart (original magnification, ×2) after receiving empty BaCaps (arrows) with x-ray/MR imaging guidance. The higher-magnification insert shows representative empty BaCaps and absence of a foreign-body reaction. (c) H-E staining of the heart (original magnification, ×2) after receiving x-ray–guided delivery of BaCaps with hMSCs without x-ray/MR imaging. Note the formation of severe fibrosis and inflammatory infiltrates around the microcapsules 1 week after delivery. (d) Human nuclear antigen staining of the heart (original magnification, ×10) after receiving BaCaps with hMSCs with x-ray/MR imaging guidance shows the presence of viable hMSCs (green) within BaCaps that adhered on the epicardial surface 1 week after delivery. Blue represents cell nuclei stained with 4’,6-diamidino-2-phenylindole, or DAPI. (e) Human nuclear antigen staining of the heart (original magnification, ×40) after receiving naked hMSCs shows no detectable hMSCs (ie, green fluorescence) 1 week after delivery. Only autofluorescence (yellow areas [arrows]) in the myocardium is observed. (f) Human nuclear antigen staining of the heart (original magnification, ×10) after receiving BaCaps with hMSCs with x-ray/MR imaging guidance shows no detectable viable hMSCs inside the microcapsules. Bars in a–c = 1 mm, and bars in d–f = 200 μm. * = epicardium.