Page 330 - IJB-10-5

International Journal of Bioprinting Immunomodulatory bone repair by MBG/PCL

Indeed, PCL possesses excellent in vivo compatibility, but Macklin (Shanghai China). Dexamethasone was obtained
the acidic products of degradation likewise induce aseptic from J&K Scientific (Beijing China). Ultrapure RNA Kit,
inflammation and promote MPs modulation and tumor HiFiScript cDNA Synthesis Kit, and Ultra SYBR Mixture
necrosis factor alpha (TNFα) expression. 26,27 However, (Low ROX) were purchased from CWBIO (Beijing China).
whether BGs can improve the immunomodulatory Alkaline phosphatase (ALP) kit, BCA protein assay kit, and
effects of PCL has rarely been reported. In addition, RIPA lysate were supplied by Biyun Tian Biotechnology
fiber thickness and pore size have a profound effect on Co. (China). Dulbecco’s modified Eagle medium (DMEM),
the immunomodulatory properties of the scaffolds. fetal bovine serum, penicillin–streptomycin solution,
Upon the expression of inflammatory genes, thicker phosphate buffer, trypsin, and CCK8 kit were obtained
fibers and larger pore sizes seem to be more favorable for from Gibco (USA). Rat bone marrow mesenchymal stem
extracellular matrix secretion and deposition, tending cells (BMSCs) and macrophage cells (RAW264.7) were
to expression of M2 phenotype genes (CD206, ARG). supplied by Gibco. Rat bone marrow mesenchymal stem
28
For example, Abebayehu et al.’s study on electrospun cells (BMSCs) and macrophage cells (RAW264.7) were
polydioxanone scaffolds reported that larger pore size supplied by ATCC (USA).
or thicker fibers tend to promote the M2 phenotype
of MPs. Zhu et al.’s study on PCL electrospun fibers 2.2. Preparation of dendritic mesoporous bioactive
29
similarly found that scaffolds with coarse fibers and large glass (MBG) and MBG/PCL scaffolds
pore sizes exhibited better immune properties. However,
30
these are basically based on studies at the nano- or tens of 2.2.1 Preparation of dendritic mesoporous bioactive
microns level. Currently, studies on immunomodulation glass (MBG)
using three-dimensional (3D)-printed BGs/PCL scaffolds SiO -CaO -P O ternary MBG were synthesized with
2
5
2
2
are relatively scarce, and there is an even greater lack reference to the previous methods. Briefly, 1.8 g of CTAC
31
of systematic studies on MPs polarization modulation was added to an appropriate amount of aqueous ethanol
and immune-coordinated osteogenesis in large fiber to form the aqueous phase, 5.2 mL of TEOS was dissolved
diameters (300–800 μm) and pore sizes (200–800 μm). in 5 mL of cyclohexane solution to form the oil phase, and
In this study, we prepared a SiO -CaO -P O ternary the oil and aqueous phases were mixed and stirred for
2
2
2
5
dendritic mesoporous structured bioactive glass (MBG) 30 min. Aqueous sodium hydroxide (1 M) was added to
with high specific surface area and pore size by sol-gel catalyze the reaction, followed by the sequential addition
method. MBG/PCL scaffolds were prepared by mixing of triethyl phosphate and tetrahydrate calcium nitrate,
different ratios of BMG powder with PCL using a fused and stirring was performed overnight. The sample was
deposition molding (FDM) 3D printer. The composite subjected to centrifugation (4000 rpm, room temperature,
scaffolds were investigated for their physicochemical 8 min) after stirring, and left to stand for 24 h to yield a
properties and immune-coordinated osteogenic white precipitate, which was washed alternately with
properties, to select the optimal MBG ratio scaffolds with anhydrous ethanol and deionized water, and MBG powder
the best compressive strength and osteogenic activity. was obtained after drying and calcination.
Finally, MBG/PCL scaffolds with different fiber diameters
and pore sizes were prepared based on the optimal MBG 2.2.2. Preparation of MBG/PCL scaffolds
ratio to explore the effects of fiber thickness and pore size MBG powders (0 mg, 50 mg, 100 mg, 200 mg, and 300 mg)
on the physicochemical properties of the scaffolds, the were weighed and dissolved in 10 mL of dichloromethane
regulation of MPs polarization to the M2 phenotype, and solution containing 1 g PCL. After stirring well, the
the promotion of osteogenic potential. solution was poured into the corresponding glass dishes
respectively, and the dichloromethane was fully evaporated
2. Materials and methods to obtain 0% MBG/PCL (0MBG/PCL), 5% MBG/PCL
2.1. Materials (5MBG/PCL), 10% MBG/PCL (10MBG/PCL), 20% MBG/
Cetyltrimethylammonium chloride (CTAC), PCL (20MBG/PCL), and 30% MBG/PCL (30MBG/ PCL)
tetraethylorthosilicate (TEOS), cyclohexane, triethyl of the scaffold feedstock. The raw materials were put
phosphate, calcium nitrate tetrahydrate, sodium into the cylinder of a 3D printer (EFL-BP-6603, Suzhou
hydroxide, anhydrous ethanol, and dichloromethane were Institute of Intelligent Manufacturing, Suzhou, China),
purchased from Guangzhou Chemical Reagent Factory heated, and melted, and subsequently, the cylindrical 3D
(China). PCL (molecular weight: 54,000) was obtained scaffolds were printed out (the diameter of the scaffolds for
from Jinan Daigang Biotech Co. (China). Vitamin C and the mechanical strength test was 10 mm and the height was
β-glycerophosphoric acid sodium were purchased from 5 mm, and the specifications of the rest of the scaffolds for

Volume 10 Issue 5 (2024) 322 doi: 10.36922/ijb.3551