Page 122 - OR-1-2

treatment, its application is often limited by donor scarcity, 2.2. Preparation of TBM
surgical site pain, and infection risks. To overcome First, 7% silk protein (S26299, Yuanye, China), 2% chitosan
9,10
these limitations, synthetic bone-filling materials, such as (C8320, Solarbio, and matrigel (354480, Corning, USA) were
metals, inorganic salts, organic polymers, and composite mixed. The mixture was then immediately supplemented
materials, have been developed. For example, composite with an equal quantity of biphasic calcium phosphate
11
scaffolds based on sodium alginate hydrogel and calcium (BCP; DULY, China) powder, thoroughly stirred at 65°C,
phosphate ceramics are widely used due to their excellent frozen at −80°C, and subsequently lyophilized. Next, the
osteoconductivity and bioabsorbability. 12,13 However, mixture was gently soaked in water and lyophilized again
certain synthetic bone-filling materials still require without freezing to form a core pillar structure (referred
improvement. For instance, most metallic bone-filling to as the Core). This structure served as a scaffold and
materials lack natural degradability, potentially leading to was coated with the same mixture (supplemented with
stress-shielding effects. 14 0.1% acrylated arginine-glycine-aspartate [RGD] peptide
Recent advancements in bone tissue engineering [EFL-Pep-RGDfkAC, engineering for life, Spain]) on the
and organoid technology have led to the development of peripheral surface. After stirring, heating to 65°C, freezing,
novel composite bone-filling materials. These materials, lyophilizing, and soaking, the material underwent a final
fabricated using tissue engineering approaches, exhibit lyophilization step following 30 min of freezing at −80°C,
high biocompatibility, mechanical robustness, and a resulting in a trabeculae-like porous skeletal structure
composition similar to natural bone tissue. Enabled by 3D (referred to as the Porous). A hyaluronic acid methacrylate
printing and rapid prototyping techniques, they allow for (HAMA; H398345, Aladdin, China) hydrogel containing
rapid mass production and customization to fit specific either a water-soluble drug (dissolved in HAMA solution) or
bone defect regions. 15-17 These characteristics have made an organic-soluble drug (dissolved in a dimethyl sulfoxide
them highly significant in the field of bone therapeutics. 18 [DMSO; BioFroxx, China] solution of photoinitiator I2959
[HY-W013508, MedChemExpress LLC, China]) was then
In this study, we developed a novel trabeculae-like overlaid onto the porous structure and crosslinked through
biomimetic bone-filling material (TBM) with a similar ultraviolet light to construct the drug-loaded TBM.
composition and porous structure closely resembling
natural bone trabecular tissues. The TBM demonstrates 2.3. Characterization of TBM
high biocompatibility, sufficient mechanical strength, The micromorphology of the TBM was examined using
and the ability to carry osteogenic cells, functioning as a scanning electron microscopy (Gemini 300, ZEISS,
potential organoid. In addition, it enables the sustained Germany) at 3 kV. Elemental composition analysis was
release of small-molecule and nucleic acid drugs tailored conducted using energy-dispersive spectroscopy (EMX,
to the primary disease, thereby accelerating bone repair HORIBA, Japan). Meanwhile, the chemical residues of
processes. This study highlights the TBM’s potential as a the TBM were analyzed using Fourier-transform infrared
functional organoid mimicking natural trabecular bone, spectroscopy (FTIR; Nicolet iS10, Thermo Fisher Scientific,
demonstrates its efficacy in treating bone defects, and USA), with a spectral range of 400 – 4,000 cm , a resolution
−1
provides a robust framework for the development of bone- of 4 cm , and a signal-to-noise ratio of 50,000:1. The
19
−1
filling materials. rheological properties of the TBM were analyzed using
2. Materials and methods an MCR92 rheometer (Anton Paar, Austria) at 25°C.
Measurements were performed within a shear strain range
2.1. Stem cells, nucleic acid delivery system, and of 0.1 – 10%. The water content of the TBM was calculated
19
animals using the following equation:
Human mesenchymal stem cells (hMSCs) were purchased Water content (%) = (W -W )/W × 100% (I)
w
w
d
from Procell (CP-H166, China). Mouse adipose-derived Where W is the wet weight of the material, and W is
mesenchymal stem cells (ADSCs) were primary cells the freeze-dried weight. 19 d
w
isolated from mice. Professor Deng Xudong from
Northwestern Polytechnical University, China, provided The swelling ratio was calculated using the following
the polyvinylamine (PVAm) nucleic acid delivery system. equation:
C57BL/6 male mice were purchased from Huafukang Swelling ratio (%) = (W -W )/W × 100% (II)
Bioscience Co., Ltd. (SCXK 2009-0008, China). All N 0 0
animal protocols received approval from our local Ethics Where W is the initial weight of the material, and W is
N
0
20
Committee (Reference: 2023078, Date: September 05, the weight after water soaking.
2023). In this study, a total of 188 mice were used, and Degradation ratios were calculated using the following
animal suffering was minimized. equation:

Volume 1 Issue 2 (2025) 2 doi: 10.36922/OR025040003