Page 284 - IJB-9-1

International Journal of Bioprinting 3D-Printed scaffolds

poly(trimethyl carbonate) (PTMC), [10,11] and poly(lactic (0 – 25% mass). PTMC/PCL/TCP composites were made
acid) (PLA) [12-14] are some of the appealing biodegradable of PTMC (50 – 37.5% mass), PCL (50 – 37.5% mass), and
materials, which are exploited as the carriers for TCP (0 – 25% mass) [27-30] . PTMC, PCL, and TCP were
bioengineering and medication delivery. Due to its mixed in dichloromethane and stirred to ensure that the
considerable biodegradability, biocompatibility, and mixture was uniformly fixed. Subsequently, the mixtures
mechanical property, PCL is suitable to be used for making were dried in vacuo to produce PCL/TCP, PTMC/TCP, and
biodegradable scaffolds for bone tissue engineering PTMC/PCL/TCP composites.
with minimal inflammatory impact of degradation PTMC/TCP, PCL/TCP, and PTMC/PCL/TCP scaffolds
compounds. However, PCL appears to be hard and have (diameter [mm] × height [mm]: 6 × 2, 10 × 2, and 4
the bulk degradability, high hydrophobicity, and crisp × 6, respectively) were produced using Regenovo 3D
characteristics [15-17] .Meanwhile, PTMC has good flexibility, Bio-Architect Pro Biological 3D printer, and the above
®
good biocompatibility and biodegradability, low toxicity, composites are used as the raw materials. The following
and surface corrosion property. Therefore, it is one of the printing conditions were adopted: Conducted at room
preferred synthetic thermoplastic biomedical polymers temperature; inner diameter of print head ≥ 0.41 mm;
for manufacturing in the scaffold for bone regeneration. extrusion pressure at 0.3 MPa; and printing rate at 6 mm/s .
[31]
However, its weak mechanical strength generally hampers
its wide application [18,19] . PTMC possesses certain good 2.2. Cell viability assay
properties that can complement and overcome the The osteoblast cell lines, clonal murine cell line of immature
disadvantages of PCL to improve the overall flexibility and osteoblasts derived from mice (MC3T3-E1) and rat bone
degradation of the scaffolds.
marrow mesenchymal stem cells (rBMSCs), were provided
β-Tricalcium phosphate (TCP) has been applied as an by the China Center for Type Culture Collection of Wuhan
ideal bone guide material in orthopedics, spine, plastic University, China . 3D-printed PTMC, PCL, PTMC/TCP,
[29]
surgery, and other fields. Its properties, such as good PCL/TCP, and PTMC/PCL/TCP scaffolds (diameter [mm]
biocompatibility and biodegradation, excellent safety, and × height [mm]: 6 × 2; different TCP content: 0 – 25%)
bone-guided regeneration ability, have been recognized by were sanitized for 1 h with ultraviolet light and fastened in
medical practitioners. TCP interacts with osteoblasts and is 24-well plate. MC3T3-E1 cells (4×10 , 200 µL) were seeded
4
catabolized to participate in the construction of new bone onto the scaffolds and cultured in the RPMI-1640 media in
through humoral dissolution and cell degradation after an incubator (37°C, 5% CO ) for 1 and 3 days before being
2
the implantation in vivo. Moreover, its other byproducts replaced with fresh growth medium. After that, cell counting
can enter the bloodstream and can be metabolized and kit 8 (CCK-8, 10 µL) solution, which was purchased from
expelled out of the body; therefore, it will not cause any Solarbio (Beijing, China), was added into each well and
damages to organs or tissues and give rise to pathological incubated for 3 h. The absorbance (OD ) was determined
450
calcification [20-24] . using a DG-3022A ELISA-Reader (iMark, BioRad, USA).
The polymeric composites with nanoceramics offer 2.3. Degradation assay
more mechanical qualities due to the dispersion of
nanoparticles in polymer matrix [25,26] . In this study, PCL All scaffolds (diameter [mm] × height [mm]: 10 × 2)
was chosen as a hard polymer matrix and further modified were sealed in a dialysis bag containing phosphate-
by PTMC, which acted as a soft polymer plasticizer, while buffered saline (PBS, 10 mL) and shaken in PBS (pH 7.4,
TCP nanomaterials were used as reinforcing fillers and 90 mL) at 37°C. The samples were taken out every month,
bone regeneration inducer. PTMC/PCL/TCP composites washed, and dried in vacuo. Following that, the samples’
in the present study were made of PTMC, PCL, and TCP. molecular weight (M ) was measured by gel permeation
n
Following that, biodegradable PTMC/PCL/TCP scaffolds chromatography, and the weight loss was determined.
were created by utilizing biological 3D printing approach, 2.4. DOX release assay
and their qualities in bone implantation applications were
also investigated. 5-DOX-Incorporated PTMC, PCL, PTMC/TCP, PCL/TCP,
and PTMC/PCL/TCP scaffolds were prepared according
2. Materials and methods to protocols described in previously published articles.
[13]
The samples sealed in a dialysis bag with PBS (10 mL) and
2.1. Preparation of PTMC/PCL/TCP scaffolds shaken slowly in PBS (pH 7.4, 90 mL) at 37°C. At different
PTMC/TCP composites were made of PTMC (100 – time points, fresh PBS (25 mL) was replaced with dialysis
75% mass) and TCP (0 – 25% mass), and PCL/TCP solution (25 mL). The variations of DOX concentrations
composites were made of PCL (100 – 75% mass) and TCP were analyzed.

Volume 9 Issue 1 (2023) 276 https://doi.org/10.18063/ijb.v9i1.641