Bioactive nanocomposite hydrogel enhances postoperative immunotherapy and bone reconstruction for osteosarcoma treatment.

Osteosarcoma, a malignant bone tumor often characterized by high hedgehog signaling activity, residual tumor cells, and substantial bone defects, poses significant challenges to both treatment response and postsurgical recovery. Here, we developed a nanocomposite hydrogel for the sustained co-delivery of bioactive magnesium ions, anti-PD-L1 antibody (αPD-L1), and hedgehog pathway antagonist vismodegib, to eradicate residual tumor cells while promoting bone regeneration post-surgery. In a mouse model of tibia osteosarcoma, this hydrogel-mediated combination therapy led to remarkable tumor growth inhibition and hence increased animal survival by enhancing the activity of tumor-suppressed CD8+ T cells. Meanwhile, the implanted hydrogel improved the microenvironment of osteogenesis through long-term sustained release of Mg2+, facilitating bone defect repair by upregulating the expression of osteogenic genes. After 21 days, the expression levels of ALP, COL1, RUNX2, and BGLAP in the Vis-αPD-L1-Gel group were approximately 4.1, 5.1, 5.5, and 3.4 times higher than those of the control, respectively. We believe that this hydrogel-based combination therapy offers a potentially valuable strategy for treating osteosarcoma and addressing the tumor-related complex bone diseases.

Biomedical applications of functional hydrogels: Innovative developments, relevant clinical trials and advanced products.

Functional hydrogels are used for numerous biomedical applications such as tissue engineering, wound dressings, lubricants, contact lenses and advanced drug delivery systems. Most of them are based on synthetic or natural polymers forming a three-dimensional network that contains aqueous media. Among synthetic polymers, poly(meth)acrylates, polyethyleneglycols, poly(vinylalcohols), poly(vinylpyrrolidones), PLGA and poly(urethanes) are of high relevance, whereas natural polymers are mainly polysaccharides such as hyaluronic acid, alginate or chitosan and proteins such as albumin, collagen or elastin. In contrast to most synthetic polymers, natural polymers are biodegradable. Both synthetic and natural polymers are often chemically modified in order to improve or induce favorable properties and functions like high mechanical strength, stiffness, elasticity, high porosity, adhesive properties, in situ gelling properties, high water binding capacity or drug release controlling properties. Within this review we provide an overview about the broad spectrum of biomedical applications of functional hydrogels, summarize innovative approaches, discuss the concept of relevant functional hydrogels that are in clinical trials and highlight advanced products as examples for successful developments.

Efficiently directing differentiation and homing of mesenchymal stem cells to boost cartilage repair in osteoarthritis via a nanoparticle and peptide dual-engineering strategy.

Mesenchymal stem cells (MSCs) are expected to be useful therapeutics in osteoarthritis (OA), the most common joint disorder characterized by cartilage degradation. However, evidence is limited with regard to cartilage repair in clinical trials because of the uncontrolled differentiation and weak cartilage-targeting ability of MSCs after injection. To overcome these drawbacks, here we synthesized CuO@MSN nanoparticles (NPs) to deliver Sox9 plasmid DNA (favoring chondrogenesis) and recombinant protein Bmp7 (inhibiting hypertrophy). After taking up CuO@MSN/Sox9/Bmp7 (CSB NPs), the expressions of chondrogenic markers were enhanced while hypertrophic markers were decreased in response to these CSB-engineered MSCs. Moreover, a cartilage-targeted peptide (designated as peptide W) was conjugated onto the surface of MSCs via a click chemistry reaction, thereby prolonging the residence time of MSCs in both the knee joint cavity of mice and human-derived cartilage. In a surgery-induced OA mouse model, the NP and peptide dual-modified W-CSB-MSCs showed an enhancing therapeutic effect on cartilage repair in knee joints compared with other engineered MSCs after intra-articular injection. Most importantly, W-CSB-MSCs accelerated cartilage regeneration in damaged cartilage explants derived from OA patients. Thus, this new peptide and NPs dual engineering strategy shows potential for clinical applications to boost cartilage repair in OA using MSC therapy.

Multilayered hydrogel scaffold construct with native tissue matched elastic modulus: A regenerative microenvironment for urethral scar-free healing.

The unsuitable deformation stimulus, harsh urine environment, and lack of a regenerative microenvironment (RME) prevent scaffold-based urethral repair and ultimately lead to irreversible urethral scarring. The researchers clarify the optimal elastic modulus of the urethral scaffolds for urethral repair and design a multilayered PVA hydrogel scaffold for urethral scar-free healing. The inner layer of the scaffold has self-healing properties, which ensures that the wound effectively resists harsh urine erosion, even when subjected to sutures. In addition, the scaffold's outer layer has an extracellular matrix-like structure that synergizes with adipose-derived stem cells to create a favorable RME. In vivo experiments confirm successful urethral scar-free healing using the PVA multilayered hydrogel scaffold. Further mechanistic study shows that the PVA multilayer hydrogel effectively resists the urine-induced inflammatory response and accelerates the transition of urethral wound healing to the proliferative phase by regulating macrophage polarization, thus providing favorable conditions for urethral scar-free healing. This study provides mechanical criteria for the fabrication of urethral tissue-engineered scaffolds, as well as important insights into their design.

Enhancing miR-19a/b induced cardiomyocyte proliferation in infarcted hearts by alleviating oxidant stress and controlling miR-19 release.

Fully restoring the lost population of cardiomyocytes and heart function remains the greatest challenge in cardiac repair post myocardial infarction. In this study, a pioneered highly ROS-eliminating hydrogel was designed to enhance miR-19a/b induced cardiomyocyte proliferation by lowering the oxidative stress and continuously releasing miR-19a/b in infarcted myocardium in situ. In vivo lineage tracing revealed that ∼20.47 % of adult cardiomyocytes at the injected sites underwent cell division in MI mice. In MI pig the infarcted size was significantly reduced from 40 % to 18 %, and thereby marked improvement of cardiac function and increased muscle mass. Most importantly, our treatment solved the challenge of animal death--all the treated pigs managed to live until their hearts were harvested at day 50. Therefore, our strategy provides clinical conversion advantages and safety for healing damaged hearts and restoring heart function post MI, which will be a powerful tool to battle cardiovascular diseases in patients.

Oxygen-defect bismuth oxychloride nanosheets for ultrasonic cavitation effect enhanced sonodynamic and second near-infrared photo-induced therapy of breast cancer.

Sonodynamic therapy (SDT) relies heavily on the presence of oxygen to induce cell death. Its effectiveness is thus diminished in the hypoxic regions of tumor tissue. To address this issue, the exploration of ultrasound-based synergistic treatment modalities has become a significant research focus. Here, we report an ultrasonic cavitation effect enhanced sonodynamic and 1208 nm photo-induced cancer treatment strategy based on thermoelectric/piezoelectric oxygen-defect bismuth oxychloride nanosheets (BNs) to realize the high-performance eradication of tumors. Upon ultrasonic irradiation, the local high temperature and high pressure generated by the ultrasonic cavitation effect combined with the thermoelectric and piezoelectric effects of BNs create a built-in electric field. This facilitates the separation of carriers, increasing their mobility and extending their lifetimes, thereby greatly improving the effectiveness of SDT and NIR-Ⅱ phototherapy on hypoxia. The Tween-20 modified BNs (TBNs) demonstrate ∼88.6 % elimination rate against deep-seated tumor cells under hypoxic conditions. In vivo experiments confirm the excellent antitumor efficacy of TBNs, achieving complete tumor elimination within 10 days with no recurrences. Furthermore, due to the high X-ray attenuation of Bi and excellent NIR-Ⅱ absorption, TBNs enable precise cancer diagnosis through photoacoustic (PA) imaging and computed tomography (CT).

An ultra-long-acting L-asparaginase synergizes with an immune checkpoint inhibitor in starvation-immunotherapy of metastatic solid tumors.

Metastasis stands as the primary contributor to mortality associated with tumors. Chemotherapy and immunotherapy are frequently utilized in the management of metastatic solid tumors. Nevertheless, these therapeutic modalities are linked to serious adverse effects and limited effectiveness in preventing metastasis. Here, we report a novel therapeutic strategy named starvation-immunotherapy, wherein an immune checkpoint inhibitor is combined with an ultra-long-acting L-asparaginase that is a fusion protein comprising L-asparaginase (ASNase) and an elastin-like polypeptide (ELP), termed ASNase-ELP. ASNase-ELP's thermosensitivity enables it to generate an in-situ depot following an intratumoral injection, yielding increased dose tolerance, improved pharmacokinetics, sustained release, optimized biodistribution, and augmented tumor retention compared to free ASNase. As a result, in murine models of oral cancer, melanoma, and cervical cancer, the antitumor efficacy of ASNase-ELP by selectively and sustainably depleting L-asparagine essential for tumor cell survival was substantially superior to that of ASNase or Cisplatin, a first-line anti-solid tumor medicine, without any observable adverse effects. Furthermore, the combination of ASNase-ELP and an immune checkpoint inhibitor was more effective than either therapy alone in impeding melanoma metastasis. Overall, the synergistic strategy of starvation-immunotherapy holds excellent promise in reshaping the therapeutic landscape of refractory metastatic tumors and offering a new alternative for next-generation oncology treatments.

Semiconducting polymer nanoprodrugs enable tumor-specific therapy via sono-activatable ferroptosis.

Ferroptosis, a recently identified form of cell death, holds promise for cancer therapy, but concerns persist regarding its uncontrolled actions and potential side effects. Here, we present a semiconducting polymer nanoprodrug (SPNpro) featuring an innovative ferroptosis prodrug (DHU-CBA7) to induce sono-activatable ferroptosis for tumor-specific therapy. DHU-CBA7 prodrug incorporate methylene blue, ferrocene and urea bond, which can selectively and specifically respond to singlet oxygen (1O2) to turn on ferroptosis action via rapidly cleaving the urea bonds. DHU-CBA7 prodrug and a semiconducting polymer are self-assembled with an amphiphilic polymer to construct SPNpro. Ultrasound irradiation of SPNpro leads to the production of 1O2 via sonodynamic therapy (SDT) of the semiconducting polymer, and the generated 1O2 activated DHU-CBA7 prodrug to achieve sono-activatable ferroptosis. Consequently, SPNpro combine SDT with the controlled ferroptosis to effectively cure 4T1 tumors covered by 2-cm tissue with a tumor inhibition efficacy as high as 100 %, and also completely restrain tumor metastases. This study introduces a novel sono-activatable prodrug strategy for regulating ferroptosis, allowing for precise cancer therapy.

Engineering mesoporous polydopamine-based potentiate STING pathway activation for advanced anti-biofilm therapy.

The biofilm-induced "relatively immune-compromised zone" creates an immunosuppressive microenvironment that is a significant contributor to refractory infections in orthopedic endophytes. Consequently, the manipulation of immune cells to co-inhibit or co-activate signaling represents a crucial strategy for the management of biofilm. This study reports the incorporation of Mn2+ into mesoporous dopamine nanoparticles (Mnp) containing the stimulator of interferon genes (STING) pathway activator cGAMP (Mncp), and outer wrapping by M1-like macrophage cell membrane (m-Mncp). The cell membrane enhances the material's targeting ability for biofilm, allowing it to accumulate locally at the infectious focus. Furthermore, m-Mncp mechanically disrupts the biofilm through photothermal therapy and induces antigen exposure through photodynamic therapy-generated reactive oxygen species (ROS). Importantly, the modulation of immunosuppression and immune activation results in the augmentation of antigen-presenting cells (APCs) and the commencement of antigen presentation, thereby inducing biofilm-specific humoral immunity and memory responses. Additionally, this approach effectively suppresses the activation of myeloid-derived suppressor cells (MDSCs) while simultaneously boosting the activity of T cells. Our study showcases the efficacy of utilizing m-Mncp immunotherapy in conjunction with photothermal and photodynamic therapy to effectively mitigate residual and recurrent infections following the extraction of infected implants. As such, this research presents a viable alternative to traditional antibiotic treatments for biofilm that are challenging to manage.

Photoswitchable dynamics and RNAi synergist with tailored interface and controlled release reprogramming tumor immunosuppressive niche.

Immunosuppressive tumor microenvironment (ITM) severely limited the efficacy of immunotherapy against triple-negative breast cancer (TNBC). Herein, Apt-LPR, a light-activatable photodynamic therapy (PDT)/RNAi immune synergy-enhancer was constructed by co-loading miR-34a and photosensitizers in cationic liposomes (in phase III clinical trial). Interestingly, the introduction of tumor-specific aptamers creates a special "Liposome-Aptamer-Target" interface, where the aptamers are initially in a "lying down" state but transform to "standing up" after target binding. The interfacing mechanism was elaborately revealed by computational and practical experiments. This unique interface endowed Apt-LPR with neutralized surface potential of cationic liposomes to reduce non-specific cytotoxicity, enhanced DNase resistance to protect aptamers, and preserved target-binding ability for selective drug delivery. Upon near-infrared irradiation, the generated reactive oxygen species would oxidize unsaturated phospholipids to destabilize both liposomes and lysosomes, realizing stepwise lysosomal escape of miR-34a for tumor cell apoptosis and downregulation of PD-L1 to suppress immune escape. Together, tumor-associated antigens released from PDT-damaged mitochondria and endoplasmic reticulum could activate the suppressive immune cells to establish an "immune hot" milieu. The collaborative immune-enhancing strategy effectively aroused systemic antitumor immunity and inhibited primary and distal tumor progression as well as lung metastasis in 4T1 xenografted mouse models. The photo-controlled drug release and specific tumor-targeting capabilities of Apt-LPR were also visualized in MDA-MB-231 xenografted zebrafish models. Therefore, this photoswitchable PDT/RNAi immune stimulator offered a powerful approach to reprogramming ITM and reinforcing cancer immunotherapy efficacy.

Manganese-coordinated nanoparticle with high drug-loading capacity and synergistic photo-/immuno-therapy for cancer treatments.

Stimulator of interferon genes (STING) agonists have shown promise in cancer treatment by stimulating the innate immune response, yet their clinical potential has been limited by inefficient cytosolic entry and unsatisfactory pharmacological activities. Moreover, aggressive tumors with "cold" and immunosuppressive microenvironments may not be effectively suppressed solely through innate immunotherapy. Herein, we propose a multifaceted immunostimulating nanoparticle (Mn-MC NP), which integrates manganese II (Mn2+) coordinated photosensitizers (chlorin e6, Ce6) and STING agonists (MSA-2) within a PEGylated nanostructure. In Mn-MC NPs, Ce6 exerts potent phototherapeutic effects, facilitating tumor ablation and inducing immunogenic cell death to elicit robust adaptive antitumor immunity. MSA-2 activates the STING pathway powered by Mn2+, thereby promoting innate antitumor immunity. The Mn-MC NPs feature a high drug-loading capacity (63.42 %) and directly ablate tumor tissue while synergistically boosting both adaptive and innate immune responses. In subsutaneous tumor mouse models, the Mn-MC NPs exhibit remarkable efficacy in not only eradicating primary tumors but also impeding the progression of distal and metastatic tumors through synergistic immunotherapy. Additionally, they contribute to preventing tumor recurrence by fostering long-term immunological memory. Our multifaceted immunostimulating nanoparticle holds significant potential for overcoming limitations associated with insufficient antitumor immunity and ineffective cancer treatment.

Local delivery of carboplatin-loaded hydrogel and calcium carbonate enables two-stage drug release for limited-dose radiation to eliminate mouse malignant glioma.

Postoperative radiotherapy remains the gold standard for malignant glioma treatment. Clinical limitations, including tumor growth between surgery and radiotherapy and the emergence of radioresistance, reduce treatment effectiveness and result in local disease progression. This study aimed to develop a local drug delivery system to inhibit tumor growth before radiotherapy and enhance the subsequent anticancer effects of limited-dose radiotherapy. We developed a compound of carboplatin-loaded hydrogel (CPH) incorporated with carboplatin-loaded calcium carbonate (CPCC) to enable two-stage (peritumoral and intracellular) release of carboplatin to initially inhibit tumor growth and to synergize with limited-dose radiation (10 Gy in a single fraction) to eliminate malignant glioma (ALTS1C1 cells) in a C57BL/6 mouse subcutaneous tumor model. The doses of carboplatin in CPH and CPCC treatments were 150 µL (carboplatin concentration of 5 mg/mL) and 15 mg (carboplatin concentration of 4.1 µg/mg), respectively. Mice receiving the combination of CPH-CPCC treatment and limited-dose radiation exhibited significantly reduced tumor growth volume compared to those receiving double-dose radiation alone. Furthermore, combining CPH-CPCC treatment with limited-dose radiation resulted in significantly longer progression-free survival than combining CPH treatment with limited-dose radiation. Local CPH-CPCC delivery synergized effectively with limited-dose radiation to eliminate mouse glioma, offering a promising solution for overcoming clinical limitations.

Red light-induced localized release of carbon monoxide for alleviating postoperative cognitive dysfunction.

Inflammation within the central nervous system (CNS), which may be triggered by surgical trauma, has been implicated as a significant factor contributing to postoperative cognitive dysfunction (POCD). The relationship between mitigating inflammation at peripheral surgical sites and its potential to attenuate the CNS inflammatory response, thereby easing POCD symptoms, remains uncertain. Notably, carbon monoxide (CO), a gasotransmitter, exhibits pronounced anti-inflammatory effects. Herein, we have developed carbon monoxide-releasing micelles (CORMs), a nanoparticle that safely and locally liberates CO upon exposure to 650 nm light irradiation. In a POCD mouse model, treatment with CORMs activated by light (CORMs + hv) markedly reduced the concentrations of interleukin (IL)-6, IL-1ß, and tumor necrosis factor-alpha (TNF-α) in both the peripheral blood and the hippocampus, alongside a decrease in ionized calcium-binding adapter molecule 1 in the hippocampal CA1 region. Furthermore, CORMs + hv treatment diminished Evans blue extravasation, augmented the expression of tight junction proteins zonula occludens-1 and occludin, enhanced neurocognitive functions, and fostered fracture healing. Bioinformatics analysis and experimental validation has identified Htr1b and Trhr as potential key regulators in the neuroactive ligand-receptor interaction signaling pathway implicated in POCD. This work offers new perspectives on the mechanisms driving POCD and avenues for therapeutic intervention.

Pulmonary delivery of silver nanoparticles prevents influenza infection by recruiting and activating lymphoid cells.

Silver nanoparticles (AgNPs) are a potential antiviral agent due to their ability to disrupt the viral particle or alter the virus metabolism inside the host cell. In vitro, AgNPs exhibit antiviral activity against the most common human respiratory viruses. However, their capacity to modulate immune responses during respiratory viral infections has yet to be explored. This study demonstrates that administering AgNPs directly into the lungs prior to infection can reduce viral loads and therefore virus-induced cytokines in mice infected with influenza virus or murine pneumonia virus. The prophylactic effect was diminished in mice with depleted lymphoid cells. We showed that AgNPs-treatment resulted in the recruitment and activation of lymphocytes in the lungs, particularly natural killer (NK) cells. Mechanistically, AgNPs enhanced the ability of alveolar macrophages to promote both NK cell migration and IFN-γ production. By contrast, following infection, in mice treated with AgNPs, NK cells exhibited decreased activation, indicating that these nanoparticles can regulate the potentially deleterious activation of these cells. Overall, the data suggest that AgNPs may possess prophylactic antiviral properties by recruiting and controlling the activation of lymphoid cells through interaction with alveolar macrophages.

Enhanced anticancer efficacy of TRAIL-conjugated and odanacatib-loaded PLGA nanoparticles in TRAIL resistant cancer.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) demonstrates unique characteristics in anticancer therapies as it selectively induces apoptosis in cancer cells. However, most cancer cells are TRAIL-resistant. Odanacatib (ODN), a cathepsin K inhibitor, is considered a novel sensitizer for cancer treatment. Combination therapy between TRAIL and sensitizers is considered a potent platform that improves TRAIL-based anticancer therapies beyond TRAIL monotherapy. Herein, we developed ODN loaded poly(lactic-co-glycolic) nanoparticles conjugated to GST-TRAIL (TRAIL-ODN-PLGA-NPs) to target and treat TRAIL-resistant cancer. TRAIL-ODN-PLGA-NPs demonstrated a significant increase in cellular uptake via death receptors (DR5 and DR4) on surface of cancer cells. TRAIL-ODN-PLGA-NPs exposure destroyed more TRAIL-resistant cells compared to a single treatment with free drugs. The released ODN decreased the Raptor protein, thereby increasing damage to mitochondria by elevating reactive oxygen species (ROS) generation. Additionally, Bim protein stabilization improved TRAIL-resistant cell sensitization to TRAIL-induced apoptosis. The in vivo biodistribution study revealed that TRAIL-ODN-PLGA-NPs demonstrated high location and retention in tumor sites via the intravenous route. Furthermore, TRAIL-ODN-PLGA-NPs significantly inhibited xenograft tumor models of TRAIL-resistant Caki-1 and TRAIL-sensitive MDA-MB-231 cells.The inhibition was associated with apoptosis activation, Raptor protein stabilizing Bim protein downregulation, Bax accumulation, and mitochondrial ROS generation elevation. Additionally, TRAIL-ODN-PLGA-NPs affected the tumor microenvironment by increasing tumor necrosis factor-α and reducing interleukin-6. In conclusion, we evealed that our formulation demonstrated synergistic effects against TRAIL compared with the combination of free drug in vitro and in vivo models. Therefore, TRAIL-ODN-PLGA-NPs may be a novel candidate for TRAIL-induced apoptosis in cancer treatment.

Photothermal switch by gallic acid-calcium grafts synthesized by coordination chemistry for sequential treatment of bone tumor and regeneration.

The residual bone tumor and defects which is caused by surgical therapy of bone tumor is a major and important problem in clinicals. And the sequential treatment for irradiating residual tumor and repairing bone defects has wildly prospects. In this study, we developed a general modification strategy by gallic acid (GA)-assisted coordination chemistry to prepare black calcium-based materials, which combines the sequential photothermal therapy of bone tumor and bone defects. The GA modification endows the materials remarkable photothermal properties. Under the near-infrared (NIR) irradiation with different power densities, the black GA-modified bone matrix (GBM) did not merely display an excellent performance in eliminating bone tumor with high temperature, but showed a facile effect of the mild-heat stimulation to accelerate bone regeneration. GBM can efficiently regulate the microenvironments of bone regeneration in a spatial-temporal manner, including inflammation/immune response, vascularization and osteogenic differentiation. Meanwhile, the integrin/PI3K/Akt signaling pathway of bone marrow mesenchymal stem cells (BMSCs) was revealed to be involved in the effect of osteogenesis induced by the mild-heat stimulation. The outcome of this study not only provides a serial of new multifunctional biomaterials, but also demonstrates a general strategy for designing novel blacked calcium-based biomaterials with great potential for clinical use.

Single-dose of integrated bilayer microneedles for enhanced hypertrophic scar therapy with rapid anti-inflammatory and sustained inhibition of myofibroblasts.

Hypertrophic scar (HS) tends to raised above skin level with high inflammatory microenvironment and excessive proliferation of myofibroblasts. The HS therapy remains challenging due to dense scar tissue which makes it hard to penetrate, and the side effects resulting from intralesional corticosteroid injection which is the mainstay treatment in clinic. Herein, bilayer microneedle patches combined with dexamethasone and colchicine (DC-MNs) with differential dual-release pattern is designed. Two drugs loaded in commercially available materials HA and PLGA, respectively. Specifically, after administration, outer layer rapidly releases the anti-inflammatory drug dexamethasone, which inhibits macrophage polarization to pro-inflammatory phenotype in scar tissue. Subsequently, inner layer degrades sustainedly, releasing antimicrotubular agent colchicine, which suppresses the overproliferation of myofibroblasts with extremely narrow therapeutic window, and inhibits the overexpression of collagen, as well as promotes the regular arrangement of collagen. Only applied once, DC-MNs directly delivered drugs to the scar tissue. Compared to traditional treatment regimen, DC-MNs significantly suppressed HS at lower dosage and frequency by differential dual-release design. Therefore, this study put forward the idea of integrated DC-MNs accompany the development of HS, providing a non-invasive, self-applicable, more efficient and secure strategy for treatment of HS.

Tumor microenvironment-modulated nanoparticles with cascade energy transfer as internal light sources for photodynamic therapy of deep-seated tumors.

Photodynamic therapy (PDT) is an appealing modality for cancer treatments. However, the limited tissue penetration depth of external-excitation light makes PDT impossible in treating deep-seated tumors. Meanwhile, tumor hypoxia and intracellular reductive microenvironment restrain the generation of reactive oxygen species (ROS). To overcome these limitations, a tumor-targeted self-illuminating supramolecular nanoparticle T-NPCe6-L-N is proposed by integrating photosensitizer Ce6 with luminol and nitric oxide (NO) for chemiluminescence resonance energy transfer (CRET)-activated PDT. The high H2O2 level in tumor can trigger chemiluminescence of luminol to realize CRET-activated PDT without exposure of external light. Meanwhile, the released NO significantly relieves tumor hypoxia via vascular normalization and reduces intracellular reductive GSH level, further enhancing ROS abundance. Importantly, due to the different ROS levels between cancer cells and normal cells, T-NPCe6-L-N can selectively trigger PDT in cancer cells while sparing normal cells, which ensured low side effect. The combination of CRET-based photosensitizer-activation and tumor microenvironment modulation overcomes the innate challenges of conventional PDT, demonstrating efficient inhibition of orthotopic and metastatic tumors on mice. It also provoked potent immunogenic cell death to ensure long-term suppression effects. The proof-of-concept research proved as a new strategy to solve the dilemma of PDT in treatment of deep-seated tumors.

A natural adhesive-based nanomedicine initiates photothermal-directed in situ immunotherapy with durability and maintenance.

Tumor immunotherapies have emerged as a promising frontier in the realm of cancer treatment. However, challenges persist in achieving localized, durable immunostimulation while counteracting the tumor's immunosuppressive environment. Here, we develop a natural mussel foot protein-based nanomedicine with spatiotemporal control for tumor immunotherapy. In this nanomedicine, an immunoadjuvant prodrug and a photosensitizer are integrated, which is driven by their dynamic bonding and non-covalent assembling with the protein carrier. Harnessing the protein carrier's bioadhesion, this nanomedicine achieves a drug co-delivery with spatiotemporal precision, by which it not only promotes tumor photothermal ablation but also broadens tumor antigen repertoire, facilitating in situ immunotherapy with durability and maintenance. This nanomedicine also modulates the tumor microenvironment to overcome immunosuppression, thereby amplifying antitumor responses against tumor progression. Our strategy underscores a mussel foot protein-derived design philosophy of drug delivery aimed at refining combinatorial immunotherapy, offering insights into leveraging natural proteins for cancer treatment.