Photocrosslinkable Materials for the Fabrication of Tissue-Engineered Constructs by Stereolithography - Tissue Engineering: Computer Modeling, Biofabrication and Cell Behavior - page 157

Fig. 8 SEM images of different 3D structures fabricated by two-photon polymerization [ 31 ]

microstructures, using methacrylated PCL-based oligomer (PCL-o) and Irgacure ®
127 as UV photoinitiator. Live/dead staining analysis showed that hESC-derived
neuronal cells, cultured on the PCL film for 7 days, were able to attach to the sur-
face, though the material did not allow cell migration.
PLA is a biodegradable polymer available in three forms: L-PLA (PLLA), D-
PLA (PDLA) and a racemic mixture of PDLLA [ 87 ]. The stereochemical structure
of PLA can be modified by polymerizing a controlled mixture of L- or D-isomers,
yielding amorphous or crystalline polymers [ 37 ]. PLA undergoes simple hydrolysis
of the ester bond, and its degradation rate is highly dependent on the isomer ra-
tio, the temperature of hydrolysis, as well the size and shape of the construct [ 37 ].
Recently, a photo-curable PDLLA-based material free of reactive diluents was de-
veloped, through functionalization with methacryloyl chloride [ 70 ]. This polymeric
system was used for the fabrication of porous scaffolds with a gyroid architecture
(Fig. 9 ), by using ethyl lactate as a non-reactive diluent. Pre-osteoblast cells, cul-
tured on the scaffolds, showed good adhesion and proliferation. Jansen et al. [ 44 ]
prepared biodegradable 3D porous scaffolds with a well-defined gyroid architecture
(Fig. 9 ) and a porosity of 76 %, using photocross-linked networks based on fu-
maric acid monoethyl ester (FAME) end-functionalized PDLLA oligomers and N-
vinyl-2-pyrrolidone, as a reactive diluent (PDLLA 3-FAME/NVP). Biological stud-
ies showed that mouse preosteoblast cells readily adhere and spread well onto disk-
shaped polymeric networks. Koroleva et al. [ 52 ] used a photocurable and biodegrad-