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Tumor surgery is usually accompanied by neoplasm residual, tissue defects, and multi-drug resistant bacterial infection, causing high tumor recurrence, low survival rate, and chronic wounds. Herein, a light-activated injectable hydrogel based on bioactive nanocomposite system is developed by incorporating Ag 2 S nanodots conjugated Fe-doped bioactive glass nanoparticles (BGN-Fe-Ag 2 S) into biodegradable PEGDA and AIPH solution for inhibiting tumor growth, treating bacterial infection, and promoting wound healing. Under laser irradiation, the photothermal effect mediated by Ag 2 S nanodots would trigger the decomposition of AIPH, generating alkyl radicals to initiate the gelation of PEGDA. The in-situ gelatinized hydrogel, with outstanding photothermal effect and chemodynamic effect derived from the doped Fe in BGN-Fe-Ag 2 S, can not only eliminate multidrug-resistant bacteria but also efficiently ablated tumor during treatment. Moreover, the hydrogel significantly accelerated wound healing with more skin appendages in the full-thickness cutaneous wounds model because of the hydrolysis of bioactive glass. These results manifest that this multifunctional hydrogel is a suitable biomaterial to inhibit tumor proliferation and overcome tissue bacterial infection after surgical removal of tumors. [ABSTRACT FROM AUTHOR]

The limited effect of immune checkpoint blockade (ICB) immunotherapy is subjected to the immuno-suppressive tumor microenvironment (TME). It is still a challenge to reverse the immune-suppressive state in clinical cancer therapy. Immunogenic cell death (ICD) is a way for inducing the therapeutical tumor immune system. In this work, carbon monoxide (CO) gas therapy is used to boost antitumor immunity for tumor control, metastasis and recurrence prevention. Briefly, CO 2 -g–C 3 N 4 –Au@ZIF-8@F127 (CCAZF) is proposed to integrate gas therapy and immunotherapy into a photocatalytic nanogenerator for overcoming the limitations of monotherapy. CCAZF exhibits a highly effective light-controllable release behavior of CO, which gradually aggravates the oxidative stress in tumor cells to induce ICD. With the induction of ICD, CO therapy enhances immune responses and enables efficient immune cells activated. When combined with ICB, CCAZF displays an enhanced immune effect, which mediates the regression of primary and distal tumors. This strategy of in-situ photocatalytic CO therapy furthest avoids the toxicity from CO leakage and provides a new method to design novel ICD inducers. • The TME-responsive ability and accuracy generation avoided the leakage of exogenous CO in vivo. • ZIF-8 shells alleviated the dependence on intracellular CO 2. • CCAZF promoted ICD both in vitro and in vivo to trigger tumor immune responses via CO therapy. • CCAZF exhibited remarkable synergism with α-PD-L1, defends against metastatic and recurrence. [ABSTRACT FROM AUTHOR]

Biomimetic materials are often capable of subtly affecting tissue development, regeneration and carcinogenesis due to their high similarity to natural tissues. Despite the benefit of using such materials in tissue engineering, their prospective use in cancer therapy has been neglected, particularly the functions and mechanisms by which biomimetic materials mediate tumor suppression. Here, we prepare hierarchically constructed bone-mimetic selenium-doped hydroxyapatite nanoparticles (B-SeHANs), which recapitulate the uniaxially oriented hierarchical structure of bone HA and can potentially play a dual role in the postoperative treatment of bone tumors via the chemotherapy from selenium and the promotion of bone repair by hydroxyapatite, to systematically investigate the influence of bone-mimetic hierarchical structure in bone tumor inhibition by SeHANs in vivo and in vitro. We found that, compared to the non-biomimetic SeHANs, the B-SeHANs exhibited highly enhanced cellular internalization and intracellular degradation, and induced subsequent autophagy and caspase-dependent apoptosis via the ROS-mediated activation of the JNK pathway and inhibition of the Akt/mTOR pathway. We further verified that the B-SeHANs promoted autophagy and apoptosis to inhibit tumor growth while profoundly reducing bone destruction in a well-designed orthotopic tibial tumor model. The current work presents a feasible strategy for the development, evaluation and fundamental study of biomimetic mineral nanoparticles to inhibit tumor growth. [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]