Aptamers are single-stranded DNA or RNA oligomers that have the ability to generate unique and diverse tertiary structures that bind to cognate molecules with high specificity. In recent years, aptamer researches have witnessed a huge surge, owing to its unique properties, such as high specificity and binding affinity, low immunogenicity and toxicity, and simplicity of synthesis with negligible batch-to-batch variation. Aptamers may bind to targets, such as various cancer biomarkers, making them applicable for a wide range of cancer diagnosis and treatment. In cancer diagnostic applications, aptamers are used as molecular probes instead of antibodies. They have the potential to detect various cancer-associated biomarkers. For cancer therapeutic purposes, aptamers can serve as therapeutic or delivery agents. The chemical stabilization and modification strategies for aptamers may expand their serum half-life and shelf life. However, aptamer-based probes for cancer diagnosis and therapy still face several challenges for successful clinical translation. A deeper understanding of nucleic acid chemistry, tissue distribution, and pharmacokinetics is required in the development of aptamer-based probes. This review summarizes their application in cancer diagnostics and treatments based on different localization of target biomarkers, as well as current challenges and future prospects.

Owing to the high penetration ability and the safety of ultrasound (US) of sonodynamic therapy (SDT), it has gained significant attention in tumor treatment. However, its therapeutic efficiency depends on the performance of the sonosensitizers. The hypoxic microenvironment and abnormal stromal matrix restrict the full potential of sonosensitizers. In this study, a US‐activated bowl‐shaped nanobomb (APBN) is designed as a novel sonosensitizer to enhance the SDT effect through various means. This enhancement strategy combines three major characteristics: relieving tumor hypoxia, amplifying bubble cavitation damage, and US‐movement‐enhanced permeation. The unique bowl‐shaped structure of APBN provides more favorable attachment sites for the generated oxygen gas bubbles. Thus, when catalase‐like APBN catalyzes endogenous hydrogen peroxide to produce oxygen, bubbles accumulate at the groove, preventing the dissipation of oxygen and increasing the number of cavitation nuclei to improve the acoustic cavitation effect. This approach differs from traditional SDT strategies because it couples the sonodynamic effect with reactive oxygen species generation and bubble cavitation damage rather than a single action. Additionally, the asymmetric bowl‐shaped structure generates a driving force under the US field, improving the distribution of sonosensitizers in the tumors. Using US and photoacoustic imaging for dual localization, these sonosensitizers can improve the accuracy of orthotopic liver tumor treatment, which presents a promising avenue for the treatment of deep tumors.

To better understand the functions and mechanisms of H₂O₂-responsive nanomaterials, key examples of their diagnosis and therapy strategies are introduced.

Skin damage is one of the most prevalent human injuries, which affects the health of human beings. However, skin damage is often accompanied by bacterial infection and wound microenvironment changes, causing damage to normal cells and inhibiting wound healing. Herein, we designed a thermal-responsive antibacterial hydrogel (GAG hydrogel) loaded with catalase (CAT)-like Au@Pt@MgSiO₃ nanoparticles (APM NPs) and gentamicin (GM) to promote wound healing. The GAG hydrogel was used in a photothermal therapy (PTT)/antibiotic combination to kill bacteria, reduce the use of antibiotics, improve the wound microenvironment, promote cell proliferation, and accelerate wound healing. Under near-infrared laser irradiation, APM NPs in the hydrogel generated local hyperthermia to kill bacteria. Meanwhile, the generated heat led to a change in the hydrogel’s morphology, enabling it to release GM and APM NPs to prevent the overuse of antibiotics. Subsequently, the CAT-like ability of the APM NPs decreased the oxidative stress caused by hydrogen peroxide (H₂O₂), thus remodeling the wound microenvironment. Then, the weakly acidic microenvironment of the wound caused the decomposition of the APM NPs and the release of magnesium ions (Mg²⁺), promoting the growth and migration of cells for wound healing. Therefore, the studied thermal-responsive antibacterial (GAG) hydrogel has potential in the field of wound healing.