Three-dimensional honeycomb porous carbon (HPC) has attracted
increasing
attention in bioengineering due to excellent mechanical properties
and a high surface-to-volume ratio. In this paper, a three-dimensional
chitosan (CS)/honeycomb porous carbon/hydroxyapatite composite was
prepared by nano-sized hydroxyapatite (nHA) on the HPC surface in
situ deposition, dissolved in chitosan solution, and vacuum freeze-dried.
The structure and composition of CS/HPC/nHA were characterized by
scanning electron microscopy, transmission electron miscroscopy, Fourier
transform infrared, and X-ray photoelectron spectroscopy, and the
porosity, swelling ratio, and mechanical properties of the scaffold
were also tested. The as-prepared scaffolds possess hierarchical pores
and organic–inorganic components, which are similar in composition
and structure to bone tissues. The synthesized composite scaffold
has high porosity and a certain mechanical strength. By culturing
mouse bone marrow mesenchymal stem cells on the surface of the scaffold,
it was confirmed that the scaffold facilitated its growth and promoted
its differentiation into the osteogenesis direction. In vivo experiments
further demonstrate that the CS/HPC/nHA composite scaffold has a significant
advantage in promoting bone formation in the bone defect area. All
the results suggested that the CS/HPC/nHA scaffolds have great application
prospect in bone tissue engineering.
The
multifunctional combined nanoplatform has a wide application
prospect in the synergistic treatment of cancer. Nevertheless, the
traditional treatment of phototherapy is limited by the catalytic
nanomaterial itself, so the effect is not satisfactory. Here, the
arris of the anisotropic truncated octahedral Au (TOh Au) was coated
with noble metal Pt to form a spatial separation structure, which
enhanced the local surface plasmonic resonance and thus boosted the
photocatalytic effect. In this system, the highly efficient photocatalysis
provides a strong guarantee for oncotherapy. On the one hand, the
structure of arris deposition adequately improves the efficiency of
photothermal conversion, which substantially improves the effectiveness
of photothermal therapy. On the other hand, in situ oxygen production of Pt ameliorates tumor hypoxia, and through the
O2 self-production and sales mode, the growth and development
of tumor were inhibited. Meanwhile, under the enhanced photocatalysis,
more O2 were produced, which greatly evolved the treatment
effect of photodynamic therapy. In the end, the addition of hyaluronic
acid can specifically target osteosarcoma cells while improving the
retention time and biocompatibility of the material in the body. Thus,
the nanocomposite shows superexcellent synergistic enhancement of
photothermal conversion efficiency and photodynamic capability in vitro and in vivo, which provides a
potential possibility for osteosarcoma cure.
Nanocomposite scaffold
materials have shown great prospect in promoting
bone integration and bone regeneration. A three-dimensional graphene
oxide foam/polydimethylsiloxane/zinc silicate (GF/PDMS/ZS) scaffold
for bone tissue engineering was synthesized via dip coating and hydrothermal
synthesis processes, resulting in the interconnected macroporous structure.
The scaffold was characterized with scanning electron microscopy (SEM),
X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and
thermogravimetric (TG) analysis. The result showed that scaffolds
exhibiting a porous characteristic had organic–inorganic components
similar to natural bone tissue. Moreover, the scaffolds possessed
suitable pore size, high porosity, and good mechanical properties. In vitro experiments with mouse bone marrow mesenchymal
stem cells (mBMSCs) revealed that the composite scaffold not only
has great biocompatibility but also has the ability to induce mBMSC
proliferation and preferential osteogentic differentiation. Thereafter,
the expression of critical genes, ALP, RUNX2, VEGFA, and OPN, was
activated. In vivo analysis of critical bone defect
in rabbits demonstrated superior bone formation in defect sites in
the GF/PDMS/ZS scaffold group at 12 weeks of post implantation without
no significant inflammatory response. All the results validated that
the GF/PDMS/ZS scaffold is a promising alternative for applications
in bone regeneration.
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