Covalent Organic Framework Nanocages with Enhanced Carrier Utilization and Cavitation Effect for Cancer Sonodynamic Therapy

Vacancy-engineered Mn-doped iron oxide nano-crystals for enhanced sonodynamic therapy through self-supplied oxygen

Sonodynamic therapy (SDT) is a minimally invasive therapeutic approach, that uses ultrasound activating sonosensitizers to generate reactive oxygen species (ROS) for inducing the tumor cell death. However, the SDT is always limited by the dissatisfactory performance of sonosensitizers and hypoxic tumor microenvironment (TME). Nano iron oxide is a narrow bandgap semiconductor material with good biocompatibility. The doping of manganese into iron oxide (Mn-doped iron oxide nano-crystals named Mn-Fe2O3 NCs) not only reduced the band gap of iron oxide and altered the valence band position of iron oxide, but also introduced more oxygen vacancies and inhibited the complexation of electrons (e-) and holes (h+), significantly enhancing the ability to generate ROS. The Mn-Fe2O3 NCs improved the hypoxic TME by self-generating oxygen and consuming endogenous glutathione (GSH), which amplified oxidative stress and further enhanced the SDT. The therapeutic results showed that the prepared Mn-Fe2O3 NCs could efficiently inhibit the triple-negative breast cancer (TNBC) cells by SDT (80.49 % inhibition ratio in vivo). Overall, we propose a simple method to design inorganic sonosensitizers for enhancing efficient sonodynamic therapy.

What Is the Magical Cavitation Bubble: A Holistic Perspective to Trigger Advanced Bubbles, Nano-Sonocatalysts, and Cellular Sonosensitizers

Sonodynamic therapy (SDT) has emerged as a novel and highly researched advancement in the medical field. Traditional ultrasound contrast agents and novel bubble-shaped agents are used to stimulate cavitation and enhance SDT efficiency. However, the impact of artificially modified shell structures on the acoustic properties of microbubbles remains to be explored. Alternatively, in the absence of bubble-shaped agents, some clinically available organic sonosensitizers and advanced inorganic materials are also used to enhance the efficacy of SDT. Diagnostic and therapeutic ultrasound can also activate cavitation bubbles, which supply energy to sonosensitive agents, leading to the production of cytotoxic free radicals to achieve therapeutic effects. While inorganic materials often spark controversy in clinical applications, their relatively simple structure enables researchers to gain insight into the mechanism by which SDT produces various free radicals. Some organic-inorganic hybrid sonosensitive systems have also been reported, combining the benefits of inorganic and organic sonosensitive agents. Alternatively, by employing cell surface modification engineering to enable cells to perform functions such as immune escape, drug loading, gas loading, and sonosensitivity, cellular sonosensitizers have also been developed. However, further exploration is needed on the acoustic properties, ability to generate reactive oxygen species (ROS), and potential clinical application of this cellular sonosensitizer. This review offers a comprehensive analysis of vesical microbubbles and nanoscale sonocatalysts, including organic, inorganic, combined organic-inorganic sonosensitizers, and cellular sonosensitizers. This analysis will enhance our understanding of SDT and demonstrate its important potential in transforming medical applications.

Fe single atoms encapsulated in N, P-codoped carbon nanosheets with enhanced peroxidase-like activity for colorimetric detection of methimazole

Excessive use of antithyroid drug methimazole (MMI) in pharmaceutical samples can cause hypothyroidism and symptoms of metabolic decline. Hence, it is urgent to develop rapid, low cost and accurate colorimetric method with peroxidase-like nanozymes for determination of MMI in medical, nutrition and pharmaceutical studies. Herein, Fe single atoms were facilely encapsulated into N, P-codoped carbon nanosheets (Fe SAs/NP-CSs) by a simple pyrolysis strategy, as certified by a series of characterizations. UV-vis absorption spectroscopy was employed to illustrate the high peroxidase-mimicking activity of the resultant Fe SAs/NP-CSs nanozyme through the typical catalysis of 3,3',5,5'-tetramethylbenzidine (TMB) oxidation. The catalytic mechanism was scrutionously investigated by the fluorescence spectroscopy and electron paramagnetic resonance (EPR) tests. Additionally, the introduced MMI had the ability to reduce the oxidation of TMB (termed oxTMB) as a peroxidase inhibitor, coupled by fading the blue color. By virtue of the above findings, a visual colorimetric sensor was established for dual detection of methimazole (MMI) with a linear scope of 5-50 mM and a LOD of 1.57 mM, coupled by assay of H2O2 at a linear range of 3-50 mM. According to the irreversible oxidation of the drug, its screening with acceptable results was achieved on the sensing platform even in commercial tablets The Fe SAs/NP-CSs nanozyme holds great potential for clinical diagnosis and drug analysis.

Integrating coaxial electrospinning and 3D printing technologies for the development of biphasic porous scaffolds enabling spatiotemporal control in tumor ablation and osteochondral regeneration

The osteochondral defects (OCDs) resulting from the treatment of giant cell tumors of bone (GCTB) often present two challenges for clinicians: tumor residue leading to local recurrence and non-healing of OCDs. Therefore, this study focuses on developing a double-layer PGPC-PGPH scaffold using shell-core structure nanofibers to achieve "spatiotemporal control" for treating OCDs caused by GCTB. It addresses two key challenges: eliminating tumor residue after local excision and stimulating osteochondral regeneration in non-healing OCD cases. With a shell layer of protoporphyrin IX (PpIX)/gelatin (GT) and inner cores containing chondroitin sulfate (CS)/poly(lactic-co-glycolic acid) (PLGA) or hydroxyapatite (HA)/PLGA, coaxial electrospinning technology was used to create shell-core structured PpIX/GT-CS/PLGA and PpIX/GT-HA/PLGA nanofibers. These nanofibers were shattered into nano-scaled short fibers, and then combined with polyethylene oxide and hyaluronan to formulate distinct 3D printing inks. The upper layer consists of PpIX/GT-CS/PLGA ink, and the lower layer is made from PpIX/GT-HA/PLGA ink, allowing for the creation of a double-layer PGPC-PGPH scaffold using 3D printing technique. After GCTB lesion removal, the PGPC-PGPH scaffold is surgically implanted into the OCDs. The sonosensitizer PpIX in the shell layer undergoes sonodynamic therapy to selectively damage GCTB tissue, effectively eradicating residual tumors. Subsequently, the thermal effect of sonodynamic therapy accelerates the shell degradation and release of CS and HA within the core layer, promoting stem cell differentiation into cartilage and bone tissues at the OCD site in the correct anatomical position. This innovative scaffold provides temporal control for anti-tumor treatment followed by tissue repair and spatial control for precise osteochondral regeneration.

Covalent Organic Frameworks: Opportunities for Rational Materials Design in Cancer Therapy

Nanomedicines are extensively used in cancer therapy. Covalent organic frameworks (COFs) are crystalline organic porous materials with several benefits for cancer therapy, including porosity, design flexibility, functionalizability, and biocompatibility. This review examines the use of COFs in cancer therapy from the perspective of reticular chemistry and function-oriented materials design. First, the modification sites and functionalization methods of COFs are discussed, followed by their potential as multifunctional nanoplatforms for tumor targeting, imaging, and therapy by integrating functional components. Finally, some challenges in the clinical translation of COFs are presented with the hope of promoting the development of COF-based anticancer nanomedicines and bringing COFs closer to clinical trials.

Optimized strategies of ROS-based nanodynamic therapies for tumor theranostics

Reactive oxygen species (ROS) play a crucial role in regulating the metabolism of tumor growth, metastasis, death and other biological processes. ROS-based nanodynamic therapies (NDTs) are becoming attractive due to non-invasive, low side effects and tumor-specific advantages. NDTs have rapidly developed into numerous branches, such as photodynamic therapy, chemodynamic therapy, sonodynamic therapy and so on. However, the complexity of the tumor microenvironment and the limitations of existing sensitizers have greatly restricted the therapeutic effects of NDTs, which heavily rely on ROS levels. To address the limitations of NDTs, various strategies have been developed to increase ROS yield, which is an urgent aspect for the positive development of NDTs. In this review, the nanodynamic potentiation strategies in terms of unique properties and universalities of NDTs are comprehensively outlined. We mainly summarize the current dilemmas faced by each NDT and the respective solutions. Meanwhile, the NDTs universalities-based potentiation strategies and NDTs-based combined treatments are elaborated. Finally, we conclude with a discussion of the key issues and challenges faced in the development and clinical transformation of NDTs.