Engineering a versatile
oncotherapy nanoplatform integrating both
diagnostic and therapeutic functions has always been an intractable
challenge in targeted cancer treatment. Herein, to actualize the theme
of precise medicine, a nanoplatform is developed by anchoring Mn-Cdots
to doxorubicin (DOX)-loaded mesoporous silica-coated gold cube-in-cubes
core/shell nanocomposites and further conjugating them to a Arg-Gly-Asp
(RGD) peptide (denoted as RGD-CCmMC/DOX) to achieve an active-targeting
effect. Under 635 nm irradiation, the nanoplatform acts as oxygen
nanogenerator that produces O2
in situ and amplifies the content of singlet oxygen (1O2) in the hypoxic tumor microenvironment (TME), which has been demonstrated
to attenuate tumor hypoxia and synchronously enhance photodynamic
efficacy. Moreover, the gold cube-in-cube core in this work has been
proven as a photothermal agent for hyperthermia, which exhibits a
favorable photothermal effect with a 65.6% calculated photothermal
conversion efficiency under 808 nm irradiation. In addition, the nanoplatform
achieves heat- and pH-sensitive drug release with precise control
to specific-tumor sites, executing combined chemo-phototherapy functions.
Besides, it functions as a multimodal bioimaging agent of photothermal,
fluorescence, and magnetic resonance imaging for the accurate diagnosis
and guidance of therapy. As validated by in vivo and in vitro assays, the TME-responsive nanoplatform is highly
biocompatible and effectively obliterates 4T1 tumor xenografts on
nude mice after triple-synergetic treatment. This work presents a
rational design of versatile nanoplatforms, which modulate the TME
to enable high therapeutic performance and multiplexed imaging, which
provides an innovative paradigm for targeted tumor therapy.
The
limited efficacy of “smart” nanotheranostic agents
in eradicating tumors calls for the development of highly desirable
nanoagents with diagnostics and therapeutics. Herein, to surmount
these challenges, we constructed an intelligent nanoregulator by coating
a mesoporous carbon nitride (C3N4) layer on
a core–shell nitrogen-doped graphene quantum dot (N-GQD)@hollow
mesoporous silica nanosphere (HMSN) and decorated it with a P-PEG-RGD
polymer, to achieve active-targeting delivery (designated as R-NCNP).
Upon irradiation, the resultant R-NCNP nanoregulators exhibit significant
catalytic breakdown of water molecules, causing a sustainable elevation
of oxygen level owing to the C3N4 shell, which
facilitates tumor oxygenation and relieves tumor hypoxia. The generated
oxygen bubbles serve as an echogenic source, triggering tissue impedance
mismatch, thereby enhancing the generation of an echogenicity signal,
making them laser-activatable ultrasound imaging agents. In addition,
the encapsulated photosensitizers and C3N4-layered
photosensitizer are simultaneously activated to maximize the yield
of ROS, actualizing a triple-photosensitizer hybrid nanosystem exploited
for enhanced PDT. Intriguingly, the N-GQDs endow the R-NCNP nanoregulator
with a photothermal effect for hyperthemia, making it exhibit considerable
photothermal outcomes and infrared thermal imaging (IRT). Importantly,
further analysis reveals that the polymer-modified R-NCNPs actively
target specific tumor tissues and display a triple-modal US/IRT/FL
imaging-assisted cooperative PTT/PDT for real-time monitoring of tumor
ablation and therapeutic evaluation. The rational synergy of triple-model
PDT and efficient PTT in the designed nanoregulator confers excellent
anticancer effects, as evidenced by in vitro and in vivo assays, which might explore more possibilities in
personalized cancer treatment.
Nanomaterials based
on hybrid scaffolds have shown a high potential
to promote osteointegration and bone regeneration. In this study,
a novel nanocomposite scaffold was synthesized via a cross-linking/hydrothermal/freeze-drying
method, resulting in layer-by-layer structures with functional and
structural properties mimicking the natural bone. The hierarchical
structures of the scaffold were reinforced with nitrogen-doped multiwalled
carbon nanotubes (N-MWCNTs), cellulose, and nanohydroxyapatite. The
N-MWCNT/Cel/nHA scaffolds were characterized and evaluated in terms
of structure, morphology, biocompatibility, cellular responses, and
bone repair efficiency in vivo. The resulting scaffolds showed that
incorporation of 1 wt % N-MWCNTs into the hybrid scaffold with micropores
(∼5 μm) significantly improved its mechanical properties,
although the surface morphology of the scaffold tended to be rough
and porous. Importantly, the resulting scaffolds supported in vitro
cellular attachment, proliferation, viability, and mineralization
of bone mesenchymal stem cells (BMSCs). On the other hand, incorporation
of N-MWCNTs into the scaffold induced preferential differentiation
of BMSCs to osteogenic lineage accompanied by increased alkaline phosphatase
activity and expression of key osteogenic genes. Furthermore, 12 weeks
after implantation, the 1%N-MWCNT/Cel/nHA porous scaffolds successfully
cicatrized a distal femoral condyle critical size defect in rabbit
without obvious inflammatory responses, as indicated by the results
of the Micro-CT and histological analyses. In vitro and in vivo experiments
confirmed that the scaffolds not only improved the interface bonding
with bone tissue but also accelerated the new bone formation and regeneration
by up-regulating signaling molecules that are involved in cell proliferation
and differentiation. These results indicated that the novel N-MWCNT/Cel/nHA
scaffold is an efficient platform for osteogenesis research and bone
regeneration medicine.
Gold nanostars (AuNSs) are nanoparticles with intricate three-dimensional structures and shape-dependent optoelectronic properties. For example, AuNSs uniquely display three distinct surface curvatures, i.e. neutral, positive, and negative, which provide different environments to adsorbed ligands. Hence, these curvatures are used to introduce different surface chemistries in nanoparticles. This review summarizes and discusses the role of surface curvature in AuNS properties and its impact on biomedical and chemical applications, including surface-enhanced Raman spectroscopy, contrast agent performance, and catalysis. We examine the main synthetic approaches to generate AuNSs, control their morphology, and discuss their benefits and drawbacks. We also describe the optical characteristics of AuNSs and discuss how these depend on nanoparticle morphology. Finally, we analyze how AuNS surface curvature endows them with properties distinctly different from those of other nanoparticles, such as strong electromagnetic fields at the tips and increased hydrophilic environments at the indentations, together making AuNSs uniquely useful for biosensing, imaging, and local chemical manipulation.
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