Fig. 6

Hydrogels can release functional Exos for therapeutic purposes for long periods. The cumulative release of PKH-26-labeled Thymosin β4 (Tβ4)-Exos bearing GelMA/PEGDA microspheres has been documented for 21 days in in vitro conditions (a). Using confocal microscopy, fluorescence images at a 3D surface plot were prepared (b - c). Continuous delivery led to the reduction of fluorescence intensity inside the microspheres by increasing the release time. A fluorescence spectrophotometer indicates the cumulative release of PKH26-labeled Tβ4-Exos over 20 days after being injected into infarcted myocardium (e). Immunofluorescence images revealed an appropriate release of loaded Tβ4-Exos in in vivo conditions (f-g). Scale bar: 15 μm [135]. Copyright 2022. Bioactive Materials