Laser

In the stereolithography apparatus (SLA), a source of high-power laser solidifies a liquid resin. In a bath full of resin, the light source can produce the desired pattern [20,53]. Superior printability and cell encapsulation capacity have been reported in the biodegradable hydrogel construct in the study of Elomaa et al. [54]. Gaebel et al. [55] introduced cardiac patches for the treatment of myocardial infarction, where cardiac patch was seeded with human umbilical vein endothelial cells and human MSC, improved wound healing and functional preservation.

The main advantage of this method is the fidelity of the achieved geometries. Complex patterns can be manufactured with high resolution, like vascular networks with wide range scales (50–250 μm) [14,56]. The contactless procedure of laser-based bioprinting prevent cells from facing mechanical stresses; thus, high cell viability is expected [53].

The disadvantage of the method is the necessity of photosensitive materials, and hence the selection of bioniks is limited [14,23]. Furthermore, the prerequisite of incorporating a cell type into a hydrogel restricts other possible bioinks [23]. In addition, the cost of the laser diodes is usually higher than its counterparts (nozzles). Moreover, future research could reveal the side effects in cells after the laser exposure during the manufacturing procedure [53].

**Table 1.** Advantages and limitations of 3D bioprinting techniques for CVD treatment.


#### 2.2.2. Biomaterials and Inks
