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The hypoxic tumor microenvironment is characterized by disordered vasculature and rapid proliferation of tumors, resulting from tumor invasion, progression and metastasis. The hypoxic conditions restrict efficiency of tumor therapies, such as chemotherapy, radiotherapy, phototherapy and immunotherapy, leading to serious results of tumor recurrence and high mortality. Recently, research has concentrated on developing functional nanomaterials to treat hypoxic tumors. In this review, we categorize such nanomaterials into (i) nanomaterials that elevate oxygen levels in tumors for enhanced oxygen-dependent tumor therapy and (ii) nanomaterials with diminished oxygen dependence for hypoxic tumor therapy. To elevate oxygen levels in tumors, oxygen-carrying nanomaterials, oxygen-generating nanomaterials and oxygen-economizing nanomaterials can be used. To diminish oxygen dependence of nanomaterials for hypoxic tumor therapy, therapeutic gas-generating nanomaterials and radical-generating nanomaterials can be used. The biocompatibility and therapeutic efficacy of these nanomaterials are discussed. [ABSTRACT FROM AUTHOR]

Surface modification of nanomaterials is essential for their biomedical applications owing to their passive immune clearance and damage to reticuloendothelial systems. Recently, a cell membrane‐coating technology has been proposed as an ideal approach to modify nanomaterials owing to its facile functionalized process and good biocompatibility for improving performances of synthetic nanomaterials. Here, recent advances of cell membrane‐coated nanomaterials are reviewed based on the main biological functions of the cell membrane in living cells. An overview of the cell membrane is introduced to understand its functions and potential applications. Then, the applications of cell membrane‐coated nanomaterials based on the functions of the cell membrane are summarized, including physical barrier with selective permeability and cellular communication via information transmission and reception processes. Finally, perspectives of biomedical applications and challenges about cell membrane‐coated nanomaterials are discussed. [ABSTRACT FROM AUTHOR]

The short lifetime of singlet oxygen reduces its accumulation in the endoplasmic reticulum, which limits the output of photodynamic therapy. A nanodevice with functions of singlet oxygen production, storage and release can improve the lifetime of singlet oxygen for enhancing phototherapeutic efficacy. [ABSTRACT FROM AUTHOR]

The clinical application of antitumor immunotherapy still faces severe challenges related to efficacy. Here, a light‐triggered core–shell nanosystem is designed to boost antitumor immune response via controlled release of anti‐PD‐L1 (αPD‐L1) antibodies and enhanced antigen presentation. The nanosystem (AZ‐P@P) is constructed via integrating gold nanorods (AuNRs) as a photothermal core and zeolitic imidazolate framework‐8 (ZIF‐8) as a shell for aPD‐L1 delivery, and further PEGylating. In the nanosystem, the ZIF‐8 shell protects αPD‐L1 antibody from the complex physiological environment and hyperthermia. Once accumulated at the tumor site, AZ‐P@P under near‐infrared (NIR) light‐triggered heating induces tumor cell deaths releasing tumor‐derived protein antigens (TDPAs) and adenosine triphosphate (ATP). Thereafter, the released ATP degrades the ZIF‐8 shell to expose the AuNRs, which can promote intratumoral T cell infiltration by capturing TDPAs and transporting them to dendritic cells (DCs). Concurrently, a large amount of αPD‐L1 is released in situ to reinvigorate T cell activity. Mechanistic studies reveal that AZ‐P@P promotes the maturation of DCs and the infiltration of activated T cells, thus eliciting a robust antitumor immunity. It is demonstrated that AZ‐P@P triggered by NIR light can significantly destroy primary tumors and suppress metastasis. This multiple immunoregulatory system provides a promising tool for tumor treatment. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) is widely researched in tumor treatment, but its therapeutic effect is affected by oxygen (O 2) concentration of tumor site. Here, we developed a Pd-coordinated π-conjugated extended porphyrin doped porphyrin metal-organic-framework (named as PTP). PTP can achieve near infrared (NIR) O 2 concentration ratiometric imaging, solving the problems of short detection wavelengths and influence of self-concentrations. With the NIR excitation wavelength and the ability of higher singlet oxygen (1O 2) generation, PTP can induce PDT more effectively. The efficient PDT also mediates cancer immunogenic cell death (ICD), which combines with the immune checkpoint inhibitor αPD-1 to achieve obviously cancer suppression and anti-metastasis effect. This theranostic NIR ratiometric nanoprobe can be used as a pre-evaluation on the outcome of PDT and high-efficient cancer combined treatment system, which will find great potential in tumor diagnosis and treatment. The theranostic near infrared ratiometric nanoprobe (PTP) could not only overcome the light penetration and influence of self-concentration in imaging O 2 but also achieve good tumor treatment results by combination of photodynamic therapy and immunotherapy. [Display omitted] [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) is a promising treatment modality for tumor suppression. However, the hypoxic state of most solid tumors might largely hinder the efficacy of PDT. Here, a functional covalent organic framework (COF) is fabricated to enhance PDT efficacy by remodeling the tumor extracellular matrix (ECM). Anti-fibrotic drug pirfenidone (PFD) is loaded in an imine-based COF (COF TTA-DHTA) and followed by the decoration of poly(lactic-co-glycolic-acid)-poly(ethylene glycol) (PLGA-PEG) to fabricate PFD@COF TTA-DHTA @PLGA-PEG, or PCPP. After injected intravenously, PCPP can accumulate and release PFD in tumor sites, leading to down-regulation of ECM compenents such as hyaluronic acid (HA) and collagen I. Such depletion of tumor ECM reduces the intratumoral solid stress, a compressive force exerted by the ECM and cells, decompresses tumor blood vessels, and increases the density of effective vascular areas, resulting in significantly improved oxygen supply in tumor. Furthermore, PCPP-mediated tumor ECM depletion also enhances the tumor uptake of subsequently injected Protoporphyrinl IX (PPIX)-conjugated peptide formed nanomicelles (NM-PPIX) due to the improved enhanced permeability and retention (EPR) effect. Both the alleviated tumor hypoxia and improved tumor homing of photosensitizer (PS) molecules after PCPP treatment significantly increase the reactive oxygen species (ROS) generation in tumor and therefore realize greatly enhanced PDT effect of tumor in vivo. A covalent organic framework (COF)-based nanosystem PCPP was fabricated to enhance tumor photodynamic therapy (PDT). PCPP can trigger the depletion of tumor extracellular matrix (ECM), leading to improved oxygen supply as well as photosensitizer uptake in tumor to achieve enhanced tumor PDT. Image 1 [ABSTRACT FROM AUTHOR]

Inflammation during photothermal therapy (PTT) of tumor usually results in adverse consequences. Here, a biomembrane camouflaged nanomedicine (mPDAB) containing polydopamine and ammonia borane was designed to enhance PTT efficacy and mitigate inflammation. Polydopamine, a biocompatible photothermal agent, can effectively convert light into heat for PTT. Ammonia borane was linked to the surface of polydopamine through the interaction of hydrogen bonding, which could destroy redox homoeostasis in tumor cells and reduce inflammation by H 2 release in tumor microenvironment. Owing to the same origin of outer biomembranes, mPDAB showed excellent tumor accumulation and low systemic toxicity in a breast tumor model. Excellent PTT efficacy and inflammation reduction made the mPDAB completely eliminate the primary tumors, while also restraining the outgrowth of distant dormant tumors. The biomimetic nanomedicine shows potentials as a universal inflammation-self-alleviated platform to ameliorate inflammation-related disease treatment, including but not limited to PTT for tumor. A membrane camouflaged nanomedicine based on polydopamine was reported for tumor therapy and anti-inflammation. It was found that this nanomedicine can achieve effective tumor suppression through hydrogenothermal therapy, and restrain the relapse of distant dormant tumors. Image 1 [ABSTRACT FROM AUTHOR]