Fig. 1

Efficient lentiviral transduction of 3D-tissue-engineered-skeletal muscle. A Experimental approach. Method 1: cells were transduced in 2D, before the generation of 3D-TESMs. Method 2: 3D-TESMs were generated from untransduced cells and were then transduced with lentiviral particles delivered through the cell culture medium. Method 3: 3D-TESMs were generated from untransduced cells and were then transduced with lentiviral particles delivered through the hydrogel during 3D-TESM formation. An H2B-GFP Lentivirus was used to assess the efficacy of the delivery method. B FACS analysis of the number of GFP-positive cells as a percentage of the whole population for the three delivery methods. Four H2B-GFP lentiviral concentrations were tested per method. Data are derived from three independent 3D-TESMs and expressed as mean ± SD. C Representative FACS plots from B. D Whole-mount immunofluorescent analysis of 3D-TESMs showing GFP 48 h after transduction with undiluted H2B-GFP virus using Method 2. Zoomed-in region of a single Z-stack is shown on the right. Nuclei were stained with Hoechst (in blue). E as D but for Method 3. F Sagittal Z-stack of 3D-TESMs transduced with Method 3, after 7 days of myogenic induction, stained with an anti-titin antibody (red)