Oxygen-Generating Hydrogels Overcome Tumor Hypoxia to Enhance Photodynamic/Gas Synergistic Therapy

Hypoxic environment is a bottleneck of photodynamic therapy (PDT) in tumor treatment, as oxygen is the critical substrate for photosensitivity reaction. Herein, a sustained oxygen supply system based on cerium nanoparticles and hydrogel (GHCAC) was explored for enhanced synergistic PDT and gas therapy. Ceria nanoparticles were prepared as a drug carrier by self-assembly mediated by hyaluronic acid (HA), a targeting for CD44 on cervical cancer cells, followed by photosensitizer and l-arginine (l-Arg) loading. Then, the GHCAC system was developed by incorporating a prepared nanocarrier (HCePA) and O₂-evolving agent calcium peroxide (CaO₂) into the hydrogel (Gel) developed by a poloxamer. Gel in the system could moderately infiltrate H₂O to react with CaO₂ and generate sustained oxygen using the catalase-like activity of HCePA. The system could efficiently alleviate hypoxia in tumor environments for up to 7 days, meeting the "once injection, repeat irradiation" strategy and enhanced PDT efficacy. Besides, the generated singlet oxygen (¹O₂) in the PDT process could also oxidize l-Arg into high concentrations of nitric oxide for synergistic gas therapy. The developed oxygen supplied and drug delivery Gel system is a new strategy for synergistic PDT/gas therapy to overcome cervical cancer.

Advanced applications of cerium oxide based nanozymes in cancer

Cerium oxide nanozymes have emerged as a new type of bio-antioxidants in recent years. CeO2 nanozymes possess enzyme mimetic activities with outstanding free radical scavenging activity, facile synthesis conditions, and excellent biocompatibility. Based on these extraordinary properties, use of CeO2 nanozymes has been demonstrated to be a highly versatile therapeutic method for many diseases, such as for inflammation, rheumatoid arthritis, hepatic ischemia-reperfusion injury and Alzheimer's disease. In addition to that, CeO2 nanozymes have been widely used in the diagnosis and treatment of cancer. Many examples can be found in the literature, such as magnetic resonance detection, tumour marker detection, chemotherapy, radiotherapy, photodynamic therapy (PDT), and photothermal therapy (PTT). This review systematically summarises the latest applications of CeO2-based nanozymes in cancer research and treatment. We believe that this paper will help develop value-added CeO2 nanozymes, offering great potential in the biotechnology industry and with great significance for the diagnosis and treatment of a wide range of malignancies.

Targeting Killing of Tumor Cells Based on Isoelectric Point Suitable Nanoceria-rod with High Oxygen Vacancies

Nanozymes have great potential application in tumor treatment because of their good stability, high biocompatibility, easy preparation and versatility. However, it remains a challenge to design of highly active nanozyme...

Biomedical Applications of Bacteria-Derived Polymers

Plastics have found widespread use in the fields of cosmetic, engineering, and medical sciences due to their wide-ranging mechanical and physical properties, as well as suitability in biomedical applications. However, in the light of the environmental cost of further upscaling current methods of synthesizing many plastics, work has recently focused on the manufacture of these polymers using biological methods (often bacterial fermentation), which brings with them the advantages of both low temperature synthesis and a reduced reliance on potentially toxic and non-eco-friendly compounds. This can be seen as a boon in the biomaterials industry, where there is a need for highly bespoke, biocompatible, processable polymers with unique biological properties, for the regeneration and replacement of a large number of tissue types, following disease. However, barriers still remain to the mass-production of some of these polymers, necessitating new research. This review attempts a critical analysis of the contemporary literature concerning the use of a number of bacteria-derived polymers in the context of biomedical applications, including the biosynthetic pathways and organisms involved, as well as the challenges surrounding their mass production. This review will also consider the unique properties of these bacteria-derived polymers, contributing to bioactivity, including antibacterial properties, oxygen permittivity, and properties pertaining to cell adhesion, proliferation, and differentiation. Finally, the review will select notable examples in literature to indicate future directions, should the aforementioned barriers be addressed, as well as improvements to current bacterial fermentation methods that could help to address these barriers.

Biomineralization: An Opportunity and Challenge of Nanoparticle Drug Delivery Systems for Cancer Therapy

Biomineralization is a common process in organisms to produce hard biomaterials by combining inorganic ions with biomacromolecules. Multifunctional nanoplatforms are developed based on the mechanism of biomineralization in many biomedical applications. In the past few years, biomineralization-based nanoparticle drug delivery systems for the cancer treatment have gained a lot of research attention due to the advantages including simple preparation, good biocompatibility, degradability, easy modification, versatility, and targeting. In this review, the research trends of biomineralization-based nanoparticle drug delivery systems and their applications in cancer therapy are summarized. This work aims to promote future researches on cancer therapy based on biomineralization. Rational design of nanoparticle drug delivery systems can overcome the bottleneck in the clinical transformation of nanomaterials. At the same time, biomineralization has also provided new research ideas for cancer treatment, i.e., targeted therapy, which has significantly better performance.

Nanoplatform-based cascade engineering for cancer therapy

Various therapeutic techniques have been studied for treating cancer precisely and effectively, such as targeted drug delivery, phototherapy, tumor-specific catalytic therapy, and synergistic therapy, which, however, evoke numerous challenges due to the inherent limitations of these therapeutic modalities and intricate biological circumstances as well. With the remarkable advances of nanotechnology, nanoplatform-based cascade engineering, as an efficient and booming strategy, has been tactfully introduced to optimize these cancer therapies. Based on the designed nanoplatforms, pre-supposed cascade processes could be triggered under specific conditions to generate/deliver more therapeutic species or produce stronger tumoricidal effects inside tumors, aiming to achieve cancer therapy with increased anti-tumor efficacy and diminished side effects. In this review, the recent advances in nanoplatform-based cascade engineering for cancer therapy are summarized and discussed, with an emphasis on the design of smart nanoplatforms with unique structures, compositions and properties, and the implementation of specific cascade processes by means of endogenous tumor microenvironment (TME) resources and/or exogenous energy inputs. This fascinating strategy presents unprecedented potential in the enhancement of cancer therapies, and offers better controllability, specificity and effectiveness of therapeutic functions compared to the corresponding single components/functions. In the end, challenges and prospects of such a burgeoning strategy in the field of cancer therapy will be discussed, hopefully to facilitate its further development to meet the personalized treatment demands.

Recent Advances in Tumor Microenvironment Hydrogen Peroxide-Responsive Materials for Cancer Photodynamic Therapy

Photodynamic therapy (PDT), as one of the noninvasive clinical cancer phototherapies, suffers from the key drawback associated with hypoxia at the tumor microenvironment (TME), which plays an important role in protecting tumor cells from damage caused by common treatments. High concentration of hydrogen peroxide (H₂O₂), one of the hallmarks of TME, has been recognized as a double-edged sword, posing both challenges, and opportunities for cancer therapy. The promising perspectives, strategies, and approaches for enhanced tumor therapies, including PDT, have been developed based on the fast advances in H₂O₂-enabled theranostic nanomedicine. In this review, we outline the latest advances in H₂O₂-responsive materials, including organic and inorganic materials for enhanced PDT. Finally, the challenges and opportunities for further research on H₂O₂-responsive anticancer agents are envisioned .

Recent Advances in Tumor Microenvironment Hydrogen Peroxide-Responsive Materials for Cancer Photodynamic Therapy

Photodynamic therapy (PDT), as one of the noninvasive clinical cancer phototherapies, suffers from the key drawback associated with hypoxia at the tumor microenvironment (TME), which plays an important role in protecting tumor cells from damage caused by common treatments. High concentration of hydrogen peroxide (H₂O₂), one of the hallmarks of TME, has been recognized as a double-edged sword, posing both challenges, and opportunities for cancer therapy. The promising perspectives, strategies, and approaches for enhanced tumor therapies, including PDT, have been developed based on the fast advances in H₂O₂-enabled theranostic nanomedicine. In this review, we outline the latest advances in H₂O₂-responsive materials, including organic and inorganic materials for enhanced PDT. Finally, the challenges and opportunities for further research on H₂O₂-responsive anticancer agents are envisioned .