H_(2)S-releasing adhesive hydrogel as oral radioprotectant for gastrointestinal tract radioprotection

Radiation damage can cause a series of gastrointestinal(GI)tract diseases.The development of safe and effective GI tract radioprotectants still remains a great challenge clinically.Here,we firstly report an oral radioprotectant Gel@GYY that integrates a porous gelatin-based(Gel)hydrogel and a pH-responsive hydrogen sulfide(H2S)donor GYY4137(morpholin-4-ium 4 methoxyphenyl(morpholino)phosphinodithioate).Gel@GYY has a remarkable adhesion ability and long retention time,which not only enables responsive release of low-dose H2S in stomach and subsequently sustained release of H2S in the whole intestinal tract especially in the colon,but also ensures a close contact between H2S and GI tract.The released H2S can effectively scavenge free radicals induced by X-ray radiation,reduce lipid peroxidation level,repair DNA damage and recover vital superoxide dismutase and glutathione peroxidase activities.Meanwhile,the released H2S inhibits radiation-induced activation of nuclear factorκB(NF-κB),thus reducing inflammatory cytokines levels in GI tract.After treatment,Gel@GYY displays efficient excretion from mice body due to its biodegradability.This work provides a new insight for therapeutic application of intelligent H2S-releasing oral delivery system and potential alternative to clinical GI physical damage protectant.

IR780/Gemcitabine-conjugated metal-phenolic network enhanced photodynamic cancer therapy

Photodynamic therapy (PDT) is a clinically approved cancer treatment that uses energy of light to generate active substances that cause damage to the cancer. Photosensitizers are employed to absorb light and generate toxic reactive oxygen species (ROS) to damage biomolecules like DNA. At the same time, some chemotherapy drugs like nucleotide analogues can provide mechanism-guided promotion in the treatment efficacy of PDT. However, the photosensitizer and chemotherapy drugs used in PDT is usually organic molecules, which suffers from bad solubility, fast clearance, and acute toxicity. To achieve targeted treatment, a reasonable delivery system is necessary. Therefore, we reported a metal-phenolic network where IR780 and gemcitabine were coupled chemically to overcome these shortcomings. The enhanced PDT effects can be realized by the promoted cell death both in vitro and in vivo. Moreover, the synergistic therapy also induced T-cell mediated anti-tumor immune response, which was significant for the inhibition of distant tumor growth. This work expanded the biomedical application of metal-phenolic materials and contribute to the wider application of photodynamic cancer therapy.

A platinum@polymer-catechol nanobraker enables radio-immunotherapy for crippling melanoma tumorigenesis, angiogenesis, and radioresistance

Malignant melanoma cell-intrinsic PD-1:PD-L1 interaction thrusts tumorigenesis,angiogenesis,and radioresistance via mTOR hyperactivation to aggravate circumjacent aggression.Interdicting melanoma intrinsic growth signals,including the blockade of PD-L1 and mTOR signaling concurrently,cooperative with radiotherapy may provide a vigorous repertoire to alleviate the tumor encumbrance.Thence,we design a three-pronged platinum@polymer-catechol nanobraker to deliver mTOR inhibitor TAK228 and anti-PD-L1 antibody(aPD-L1)for impeding the melanoma-PD-1-driven aggression and maximizing the melanoma eradication.The aPD-L1 collaborated with TAK228 restrains melanoma cell-intrinsic PD-1:PD-L1 tumorigenic interaction via blocking melanoma-PD-L1 ligand and the melanoma-PD-1 receptor-driven mTOR signaling;corresponding downregulation of mTOR downstream protumorigenic cellular MYC and proangiogenic hypoxia-inducible factor 1-alpha is conducive to preventing tumorigenesis and angiogenesis,respectively.Further,high-Z metal platinum sensitizing TAK228-enhanced radiotherapy confers the nanobraker on remarkable tumoricidal efficacy.Hereto,the customized three-pronged nanobrakers efficiently suppress melanoma tumorigenesis and angiogenesis concomitant with the amplification of radiotherapeutic efficacy.Such an ingenious tactic may provide substantial benefits to clinical melanoma patients.

Light-triggered nitric oxide release and structure transformation of peptide for enhanced intratumoral retention and sensitized photodynamic therapy

Tumor-targeted delivery of nanomedicine is of great importance to improve therapeutic efficacy of cancer and minimize systemic side effects.Unfortunately,nowadays the targeting efficiency of nanomedicine toward tumor is still quite limited and far from clinical requirements.In this work,we develop an innovative peptide-based nanoparticle to realize light-triggered nitric oxide(NO)release and structural transformation for enhanced intratumoral retention and simultaneously sensitizing photodynamic therapy(PDT).The designed nanoparticle is self-assembled from a chimeric peptide monomer,TPP-RRRKLVFFK-Ce6,which contains a photosensitive moiety(chlorin e6,Ce6),aβ-sheet-forming peptide domain(Lys-Leu-Val-Phe-Phe,KLVFF),an oligoarginine domain(RRR)as NO donor and a triphenylphosphonium(TPP)moiety for targeting mitochondria.When irradiated by light,the constructed nanoparticles undergo rapid structural transformation from nanosphere to nanorod,enabling to achieve a significantly higher intratumoral accumulation by 3.26 times compared to that without light irradiation.More importantly,the conversion of generated NO and reactive oxygen species(ROS)in a light-responsive way to peroxynitrite anions(ONOO)with higher cytotoxicity enables NO to sensitize PDT in cancer treatment.Both in vitro and in vivo studies demonstrate that NO sensitized PDT based on the well-designed transformable nanoparticles enables to eradicate tumors efficiently.The light-triggered transformable nanoplatform developed in this work provides a new strategy for enhanced intratumoral retention and improved therapeutic outcome.

A"three musketeers"tactic for inclining interferon-γ as a comrade-in-arm to reinforce the synergistic-tumoricidal therapy

Interferon-γ(IFN-γ),secreted by activated T cells predominantly,plays a crucial performance in the tumoricidal immune response.Unfortunately,a high level of IFN-γseverely ignites the immunosuppressive response,especially by increasing the expression of immune checkpoint programmed death-ligand 1(PD-L1)and immunoregulatory enzyme indoleamine 2,3-dioxygenase 1(IDO-1).Herein,we have explored a versatile IFN-γ-nano-integrator(aPD-L1-SH@Ce6@NLG919-PEG,simplified as CNDP)to establish a positive anti-tumor feedback loop to amplify the IFN-γ-mediated tumoricidal effect.In this nanointegrator,photosensitizer chlorin e6(Ce6)mediates photodynamic therapy(PDT)to re-shape immunogenicity and activate the adaptive immune response,followed by the secretion of high-level IFN-γto struggle tumor cells.IDO-1 inhibitor(NLG919)afterwards mitigates the immunosuppressive behavior of IFN-γby neutralizing the function of IDO-1.To turn“waste”into wealth,anti-PD-L1(aPD-L1)antibodies are technically integrated into the nano-integrator to propel the precise attack of breast cancer through ascending PD-L1 blockade.Together,this“three musketeers”nano-integrator tumoricidal tactic may give a unique insight into the clinical anti-tumor therapy.

NIR-Ⅱ-absorbing conjugated polymer-based theranostic agent for NIR-Ⅱfluorescence imaging-guided photothermal therapy acting synergistically with tumor microenvironment-responsive nitric oxide therapy

Despite tremendous advances in gas therapy,there are major concerns about the inevitable concentration of toxicity and the ability to perform real-time tracking of drug delivery.Second near-infrared(NIR-Ⅱ)window absorbing nanoplatforms hold great promise for precision medicine because of their excellent tissue penetration of light and non-invasive nature.In this study,we engineered an NIR-Ⅱlaser-activated theranostic agent(named CP-bF@PEG)that was composed of amphiphilic polymers(Pluronic F127,with polyethylene glycol,PEG,moieties)coated with an NIR-Ⅱ-absorbing conjugated polymer(PTTBBT,CP)and nitric oxide(NO)donor(benzofuroxan,bF),which served as an NIR-Ⅱphotothermal inducer and NO nanogenerator.Under deep tissue penetration of NIR-Ⅱlaser irradiation,CP-bF@PEG was found to possess fluorescence imaging ability to accurately identify tumor and excellent photothermal effect.Moreover,CP-bF@PEG could generate NO via glutathione activation in the tumor microenvironment in a controllable manner.This NIR-Ⅱ-absorbing polymer for high-contrast NIR-Ⅱfluorescence imaging-guided precision photothermal therapy achieved synergistic effects with NO therapy,as evidenced by pronounced tumor therapeutic efficacy and few side effects.This nanotheranostic agent is a highly promising candidate for high-contrast NIR-Ⅱimaging-guided precision photothermal therapy combined with gas therapy against cancer.