Mechano-Activated Cell Therapy for Accelerated Diabetic Wound Healing.

Chronic diabetic wounds are a significant global healthcare challenge. Current strategies, such as biomaterials, cell therapies, and medical devices, however, only target a few pathological features and have limited efficacy. A powerful platform technology combining magneto-responsive hydrogel, cells, and wireless magneto-induced dynamic mechanical stimulation (MDMS) is developed to accelerate diabetic wound healing. The hydrogel encapsulates U.S. Food and Drug Administration (FDA)-approved fibroblasts and keratinocytes to achieve ∼3-fold better wound closure in a diabetic mouse model. MDMS acts as a nongenetic mechano-rheostat to activate fibroblasts, resulting in ∼240% better proliferation, ∼220% more collagen deposition, and improved keratinocyte paracrine profiles via the Ras/MEK/ERK pathway to boost angiogenesis. The magneto-responsive property also enables on-demand insulin release for spatiotemporal glucose regulation through increasing network deformation and interstitial flow. By mining scRNAseq data, a mechanosensitive fibroblast subpopulation is identified that can be mechanically tuned for enhanced proliferation and collagen production, maximizing therapeutic impact. The "all-in-one" system addresses major pathological factors associated with diabetic wounds in a single platform, with potential applications for other challenging wound types.

Injectable microenvironment-responsive hydrogels with redox-activatable supramolecular prodrugs mediate ferroptosis-immunotherapy for postoperative tumor treatment.

Immunotherapy is an emerging antitumor modality with high specificity and persistence, but its application for resected tumor treatment is impeded by the low availability of tumor-specific antigens and strong immunosuppression in the wound margin. Here a nanoengineered hydrogel is developed for eliciting robust cooperative ferroptosis-immunotherapeutic effect on resected tumors. Specifically, ß-cyclodextrin (ß-CD) is first grafted onto oxidized sodium alginate (OSA) through Schiff base ligation, which could trap cRGD-modified redox-responsive Withaferin prodrugs (WA-cRGD) to obtain the hydrogel building blocks (Gel@WA-cRGD). Under Ca2+-mediated crosslinking, Gel@WA-cRGD rapidly forms physiologically stable hydrogels, of which the porous network is used to deliver programmed cell death ligand 1 antibodies (aPD-L1). After injection into the post-surgical wound cavity, the ß-CD-entrapped WA-cRGD is detached by the local acidity and specifically internalized by residual tumor cells to trigger ferroptosis, thus releasing abundant damage-associated molecular patterns (DAMPs) and tumor-derived antigens for activating the antigen-presenting cell-mediated cross-presentation and downstream cytotoxic T cell (CTL)-mediated antitumor responses. Furthermore, aPD-L1 could block PD-1/PD-L1 interaction and enhance the effector function of CTLs to overcome tumor cell-mediated immunosuppression. This cooperative hydrogel-based antitumor strategy for ferroptosis-immunotherapy may serve as a generally-applicable approach for postoperative tumor management. STATEMENT OF SIGNIFICANCE: To overcome the immunosuppressive microenvironment in resected solid tumors for enhanced patient survival, here we report a nanoengineered hydrogel incorporated supramolecular redox-activatable Withaferin prodrug and PD-L1 antibody, which could elicit robust cooperative ferroptosis-immunotherapeutic effect against residual tumor cells in the surgical bed to prevent tumor relapse, thus offering a generally-applicable approach for postoperative tumor management.

ROS-activatable biomimetic interface mediates in-situ bioenergetic remodeling of osteogenic cells for osteoporotic bone repair.

Bioenergy (ATP) is essentially required for supporting the osteogenic differentiation of bone marrow mesenchymal stem cells (MSCs). However, factors such as high ROS levels and decreased glucose metabolism severely limit the bioenergy production in osteoporotic MSCs. We have prepared CaCO3-Quercetin- chromium (CaCO3-Qu-Cr) nanoparticles via ion coordination and packaged them into ROS-responsive gelatin/chitosan coating on titanium surface (Ti/Gel/CaCO3-Qu-Cr), aiming to improve the ATP production and cell mineralization by ameliorating ROS levels via Qu-mediated antioxidative effect and the promotional effect of Qu-Cr combination on glucose metabolism. Characterization results confirmed that Ti/Gel/CaCO3-Qu-Cr could be degraded in an ROS-responsive manner to release CaCO3-Qu-Cr nanoparticles continuously and eliminate excessive ROS in both the MSCs and microenvironment. Meanwhile, Ti/Gel/CaCO3-Qu-Cr significantly increased the glucose uptake and metabolism in osteoporotic MSCs and boosted their ATP and citrate production. This study laid the foundation for the development of functional titanium-based implants for the improvement of osteoporotic osseointegration.

Bio-inspired engineered ferritin-albumin nanocomplexes for targeted ferroptosis therapy.

Nanotechnology-enabled ferroptosis therapy is an emerging paradigm for tumor treatment, but amplifying ferroptotic damage in tumor cells in a safe and selective manner is still challenging, which severely hinders its clinical translation. In this study, we constructed a bio-inspired protein nanocomplex based on natural-occurring bovine serum albumin (BSA) and ferritin for efficient tumor elimination via cooperatively enhanced ferroptosis therapy. The long-circulating BSA molecules provided multiple anchoring points for the efficient loading of the GPX4-inhibiting ferroptosis inducer (1S, 3R) RAS-selective lethal 3 (RSL3), which was further complexed with ferritin via acidity-responsive glutaraldehyde linkers. The ferritin moieties may not only bind to transferrin receptor 1 overexpressed on tumor cell membrane for targeted endocytic uptake but also be degraded in lysosomes to induce iron overload, which could substantially promote the lipid peroxidation in tumor cells and cooperate with the glutathione peroxidase 4 (GPX4)-inhibiting capability of RSL3 to induce pronounced ferroptosis. The in vitro and in vivo results collectively demonstrated that the albumin-ferritin-based nanocomplex could present superior antitumor effects with no obvious adverse effects, which may open new avenues for the clinical translation of ferroptosis-dependent therapeutic modalities.

A protein-based cGAS-STING nanoagonist enhances T cell-mediated anti-tumor immune responses.

cGAS-STING pathway is a key DNA-sensing machinery and emerges as a promising target to overcome the immunoresistance of solid tumors. Here we describe a bovine serum albumin (BSA)/ferritin-based nanoagonist incorporating manganese (II) ions and ß-lapachone, which cooperatively activates cGAS-STING signaling in dendritic cells (DCs) to elicit robust adaptive antitumor immunity. Mn2+-anchored mannose-modified BSAs and ß-lapachone-loaded ferritins are crosslinked to afford bioresponsive protein nanoassemblies, which dissociate into monodispersive protein units in acidic perivascular tumor microenvironment (TME), thus enabling enhanced tumor penetration and spatiotemporally controlled Mn2+ and ß-lapachone delivery to DCs and tumor cells, respectively. ß-lapachone causes immunogenic tumor cell apoptosis and releases abundant dsDNA into TME, while Mn2+ enhances the sensitivity of cGAS to dsDNA and augments STING signaling to trigger downstream immunostimulatory signals. The cGAS-STING nanoagonist enhances the tumor-specific T cell-mediated immune response against poorly immunogenic solid tumors in vivo, offering a robust approach for immunotherapy in the clinics.

Cell-Specific Metabolic Reprogramming of Tumors for Bioactivatable Ferroptosis Therapy.

Ferroptosis is a nonapoptotic iron-dependent cell death pathway with a significant clinical potential, but its translation is impeded by lack of tumor-specific ferroptosis regulators and aberrant tumor iron metabolism. Herein, we report a combinational strategy based on clinically tested constituents to selectively induce ferroptosis in metabolically reprogrammed tumor cells through cooperative GPX4-inhibition and ferritinophagy-enabled Fe2+ reinforcement. Azido groups were first introduced on tumor cells using biocompatible long-circulating self-assemblies based on polyethylene glycol-disulfide-N-azidoacetyl-d-mannosamine via metabolic glycoengineering. The azido-expressing tumor cells could specifically react with dibenzocyclooctyne-modified disulfide-bridged nanoassemblies via bioorthogonal click reactions, where the nanoassemblies were loaded with ferroptosis inducer RSL3 and ferritinophagy initiator dihydroartemisinin (DHA) and could release them in a bioresponsive manner. DHA-initiated ferritinophagy could degrade intracellular ferritin to liberate stored iron species and cooperate with the RSL3-mediated GPX4-inhibition for enhanced ferroptosis therapy. This tumor-specific ferroptosis induction strategy provides a generally applicable therapy with enhanced translatability, especially for tumors lacking targetable endogenous receptors.

An ROS-Activatable Nanoassembly Remodulates Tumor Cell Metabolism for Enhanced Ferroptosis Therapy.

Ferroptosis is an emerging antitumor option and has demonstrated unique advantages against many tumor indications. However, its efficacy is potentially hindered by the endogenous lipid peroxide-scavenging mechanisms and the reliance on acidic pH. Herein, a nanointegrated strategy based on clinically-safe components to synergistically remodel glutathione and lactate metabolism in tumor cells for enhanced ferroptosis therapy is developed. First ferrocene is conjugated on PEGylated polyamidoamine dendrimers via reactive oxygen species (ROS)-cleavable thioketal linkage, which would further self-assemble with the glutathione (GSH)-depleting agent diethyl maleate (DEM) and monocarboxylate transporter 4-inhibiting siRNA (siMCT4) to afford biostable nanoassemblies (siMCT4-PAMAM-PEG-TK-Fc@DEM). The nanoassemblies can be activated by the elevated ROS levels in tumor intracellular environment and readily release the incorporated therapeutic contents, afterward DEM can directly conjugate to GSH to disrupt the glutathione peroxidase 4 (GPX4)-mediated antioxidant defense, while siMCT4 can block the MCT4-mediated efflux of lactic acid and acidify the intracellular milieu, both of which can improve the ferrocene-catalyzed lipid peroxidation and induce pronounced ferroptotic damage. The siMCT4-PAMAM-PEG-TK-Fc@DEM nanoplatform demonstrates high ferroptosis-based antitumor potency and good biocompatibility in vitro and in vivo, which may offer new avenues for the development of more advanced antitumor therapeutics with improved translatability.

Tumor-activatable biomineralized nanotherapeutics for integrative glucose starvation and sensitized metformin therapy.

Metformin is a clinically-approved anti-diabetic drug with emerging antitumor potential, but its antitumor activity is highly susceptible to local glucose abundance. Herein, we construct a nanotherapeutic platform based on biocompatible constituents to sensitize tumor cells for metformin therapy via cooperative glucose starvation. The nanoplatform was synthesized through the spontaneous biomineralization of glucose oxidase (GOx) and metformin in amorphous calcium phosphate nanosubstrate, which was further modified with polyethylene glycol and cRGD ligands. This biomineralized nanosystem could efficiently deliver the therapeutic payloads to tumor cells in a targeted and bioresponsive manner. Here GOx could catalyze the oxidation of glucose into gluconic acid and H2O2, thus depleting the glucose in tumor intracellular compartment while accelerating the release of the entrapped therapeutic payloads. The selective glucose deprivation would not only disrupt tumor energy metabolism, but also upregulate the PP2A regulatory subunit B56δ and sensitize tumor cells to the metformin-induced CIP2A inhibition, leading to efficient apoptosis induction via PP2A-GSK3ß-MCL-1 axis with negligible side effects. This study may offer new avenues for targeted tumor therapy in the clinical context.

Activatable Biomineralized Nanoplatform Remodels the Intracellular Environment of Multidrug-Resistant Tumors for Enhanced Ferroptosis/Apoptosis Therapy.

Ferroptosis is a new form of regulated cell death with significant therapeutic prospect, but its application against drug-resistant tumor cells is challenging due to their ability to effuse antitumor agents via p-glycoprotein (P-gp) and anti-lipid peroxidation alkaline intracellular environment. Herein, an amorphous calcium phosphate (ACP)-based nanoplatform is reported for the targeted combinational ferroptosis/apoptosis therapy of drug resistant tumor cells by blocking the MCT4-mediated efflux of lactic acid (LA). The nanoplatform is fabricated through the biomineralization of doxorubicin-Fe2+ (DOX-Fe2+ ) complex and MCT4-inhibiting siRNAs (siMCT4) and can release them to the tumor cytoplasm after the hydrolysis of ACP and dissociation of DOX-Fe2+ in the acidic lysosomes. siMCT4 can inhibit MCT4 expression and force the glycolysis-generated lactic acid (LA) to remain in cytoplasm for rapid acidification. The nanoplatform-induced remodeling of the tumor intracellular environment can not only interrupt the ATP supply required for P-gp-dependent DOX effusion to enhance H2 O2 production, but also increase the overall catalytic efficiency of Fe2+ for the initiation and propagation of lipid peroxidation. These features could act in concert to enhance the efficacy of the combinational ferroptosis/chemotherapy and prolong the survival of tumor-bearing mice. This study may provide new avenues for the treatment of multidrug-resistant tumors.

NIR-Actuated Remote Activation of Ferroptosis in Target Tumor Cells through a Photothermally Responsive Iron-Chelated Biopolymer Nanoplatform.

Ferroptosis is a new form of regulated cell death that shows promise for tumor treatment. Most current ferroptosis tumor therapies are based on the intrinsic pathological features of the malignancies, and it would be of clinical significance to develop ferroptosis-inducing strategies with improved tumor specificity and modulability. Here we report a polydopamine-based nanoplatform (FeII PDA@LAP-PEG-cRGD) for the efficient loading of Fe2+ and ß-lapachone (LAP), which could readily initiate ferroptosis in tumor cells upon treatment with near-infrared light. PDA nanostructures could generate mild hyperthermia under NIR irritation and trigger the release of the ferroptosis-inducing Fe2+ ions. The NIR-actuated photothermal effect would also activate cellular heat shock response and upregulate the downstream NQO1 via HSP70/NQO1 axis to facilitate bioreduction of the concurrently released ß-lapachone and enhance intracellular H2 O2 formation to promote the Fe2+ -mediated lipid peroxidation.

Implantable multifunctional black phosphorus nanoformulation-deposited biodegradable scaffold for combinational photothermal/ chemotherapy and wound healing.

Surgery is the mainstream treatment for melanoma, but its clinical implementation suffers from some major drawbacks including residual infiltrating melanoma cells at resection margins and severe tissue injury. In this study, a nanocomposite scaffold is developed for in-situ therapy after melanoma surgery as well as wound healing, which is fabricated by embedding photothermal-capable black phosphorus nanosheets (BPNSs) into bioresorbable Gelatin-PCL (GP) nanofibrous scaffold. GP scaffold is a clinically-tested biomaterial with temperature sensitivity and tissue-healing effect, while the BPNSs are loaded with the anticancer antibiotic of doxorubicin (DOX) and conjugated with NH2-PEG-FA for tumor-targeted delivery. The GP scaffold could undergo a sol-gel transition upon NIR irritation and release the BPNSs in situ. During this process, most of the BP-based nanoformulations were selectively internalized by the melanoma cells for the cooperative photothermal therapy and heat-triggerable DOX therapy, while some of the loaded DOX was released into the wound tissue to create a tumor-suppressive microenvironment. Moreover, BPNSs could be gradually degraded to phosphates/phosphonates and thus enhance tissue repair by activating the ERK1/2 and PI3K/Akt pathway. Meanwhile, the detached DOX molecules would also enter the wound tissues for continuous melanoma inhibition. Considering the anti-melanoma and wound healing effect of this composite scaffold, it may offer a facile strategy for the wound treatment after melanoma surgery.

Hierarchical integration of degradable mesoporous silica nanoreservoirs and supramolecular dendrimer complex as a general-purpose tumor-targeted biomimetic nanoplatform for gene/small-molecule anticancer drug co-delivery.

Biomacromolecule therapeutic systems are intrinsically susceptible to degradation and denaturation. Nanoformulations are promising delivery vehicles for therapeutic biomacromolecules (antibodies, genes and so on). However, their applications in these areas still face many challenges including in vivo stability, premature leakage and accurate tumor recognition. In this study, a generally applicable new strategy for tumor-targeted delivery of biomacromolecules was developed through the hierarchical integration of degradable large-pore dendritic mesoporous silica nanoparticles (dMSNs) and cyclodextrin-modified polyamidoamine (PAMAM-CD) dendrimers. The orifice rim of the dMSNs was modified with ROS-responsive nitrophenyl-benzyl-carbonate (NBC) groups while disulfide-bonded azido ligands were subsequently grafted onto the inner channel walls via heterogeneous functionalization. The PAMAM-CD was then interred into the dendritic pores via click reactions and supramolecularly loaded with archetypal hydrophobic small-molecule anticancer model drug (SN-38) and therapeutic model gene (Bcl-2 siRNA), after which dMSNs were eventually coated with a 4T1 cancer cell membrane (CCM). Experimental evidence demonstrated that the synthesized nanocarriers could efficiently deliver therapeutic cargos to target cancer cells and release them in the tumor cytosol in a cascade-responsive manner. This biomimetic nanoplatform presents a novel strategy to efficiently deliver biomolecular therapeutics in a tumor-targeted manner.

Tumor microenvironment-activatable Fe-doxorubicin preloaded amorphous CaCO3 nanoformulation triggers ferroptosis in target tumor cells.

The rapid development of treatment resistance in tumors poses a technological bottleneck in clinical oncology. Ferroptosis is a form of regulated cell death with clinical translational potential, but the efficacy of ferroptosis-inducing agents is susceptible to many endogenous factors when administered alone, for which some cooperating mechanisms are urgently required. Here, we report an amorphous calcium carbonate (ACC)-based nanoassembly for tumor-targeted ferroptosis therapy, in which the totally degradable ACC substrate could synergize with the therapeutic interaction between doxorubicin (DOX) and Fe2+. The nanoplatform was simultaneously modified by dendrimers with metalloproteinase-2 (MMP-2)-sheddable PEG or targeting ligands, which offers the functional balance between circulation longevity and tumor-specific uptake. The therapeutic cargo could be released intracellularly in a self-regulated manner through acidity-triggered degradation of ACC, where DOX could amplify the ferroptosis effects of Fe2+ by producing H2O2. This nanoformulation has demonstrated potent ferroptosis efficacy and may offer clinical promise.

Osteogenic differentiation of mesenchymal stem cells by silica/calcium micro-galvanic effects on the titanium surface.

Based on the sensitivity to the extracellular H+ concentration of proton-sensing receptors, we immobilized Si/CaCO3 nanoparticles on a titanium surface (TiMNPs) by using micro-arc oxidation (MAO) to produce micro-galvanic effects by Schottky contact, aiming to regulate the hydrogen evolution reaction of micro-galvanic couples and osteogenic response of mesenchymal stem cells (MSCs). The surface zeta potential measurement and dynamic potential polarization test confirmed that micro-galvanic effects were successfully produced on the titanium surface after the treatment of Si/CaCO3 nanoparticles. The Ti substrate with a Si/CaCO3 nanoparticle loading concentration of 100 mg mL-1 (TiMNPs 100) could lead to the highest level of hydrogen evolution reaction. In vitro experiments showed that TiMNPs 100 were significantly superior in their ability to down-regulate the expression level of proton-sensing receptors and key proteins in the PLC/Ca2+ signal pathway, which in turn promoted MSC osteogenesis differentiation. A higher level of ALP activity, mineralization capacity and collagen secretion on TiMNPs 100 was confirmed as compared to those of other groups. This study provides a new insight into designing novel biomaterials for bone generation.

Polarization of tumor-associated macrophage phenotype via porous hollow iron nanoparticles for tumor immunotherapy in vivo.

Tumor-associated macrophages (TAMs) are the most important components in the tumor immunosuppressive microenvironment, promoting tumor growth and metastasis. Although TAMs have become one of the hot topics of tumor immunotherapy, challenges still remain to achieve TAM-targeted re-polarization therapy. In this work, porous hollow iron oxide nanoparticles (PHNPs) were synthesized for loading a P13K γ small molecule inhibitor (3-methyladenine, 3-MA) and further modified by mannose to target TAMs. The delivery system named PHNPs@DPA-S-S-BSA-MA@3-MA showed good efficiency for targeting TAMs. The inflammatory factor NF-κB p65 of macrophages was activated by the combination of PHNPs and 3-MA, which synergistically switched TAMs to pro-inflammatory M1-type macrophages. As a result, it activated immune responses and inhibited tumor growth in vivo. The study provides an intracellular switch of the TAM phenotype for targeted TAM therapy.

Oxygenated theranostic nanoplatforms with intracellular agglomeration behavior for improving the treatment efficacy of hypoxic tumors.

Hypoxia plays vital roles in the development of tumor resistance against typical anticancer therapies and local reoxygenation has proved effective to overcome the hypoxia-induced chemoresistance. Perfluorocarbon (PFC) is an FDA approved oxygen carrier and currently vigorously investigated for oxygen delivery to tumors. This study reports a perfluorocarbon and etoposide (EP) loaded porous hollow Fe3O4-based theranostic nanoplatform capable of delivering oxygen to solid tumors to enhance their susceptibility against EP. Results show that oxygen could be released at a moderate rate from the porous hollow magnetic Fe3O4 nanoparticles (PHMNPs) over an extended period of time, therefore effectively reducing the hypoxia-induced EP resistance of tumor cells. Moreover, the surface of PHMNPs was modified with lactobionic acid (LA)-containing amphiphilic polymers via hydrophobic interaction, which could provide targeting effect against certain types of tumors. The hydrophilic moiety would be subsequently shed by the intratumoral GSH after cellular internalization and result in the agglomeration of nanocarriers inside tumor cells, consequently impeding the nanoparticle exocytosis to enhance their intracellular retention. The enhanced retention could elevate the intracellular EP level and effectively boost the tumor cell killing effect. In addition to the therapeutic benefits, the Fe3O4 nanocage could also be used for the magnetic resonance imaging of the tumor area. The assorted benefits of the composite nanosystem are anticipated to be advantageous for the treatment of drug-resistant hypoxic tumors.

An autonomous tumor-targeted nanoprodrug for reactive oxygen species-activatable dual-cytochrome c/doxorubicin antitumor therapy.

The precise tumor cell-specific delivery of therapeutic proteins and the elimination of side effects associated with routine chemotherapeutic agents are two current critical considerations for tumor therapy. In this study, we report a reactive oxygen species (ROS)-activated yolk-shell nanoplatform for the tumor-specific co-delivery of cytochrome c (Cyt c) prodrug and doxorubicin, in which the bioactivity of Cyt c could be restored by the intracellular ROS-trigger and readily initiate the sequential doxorubicin release. The DOX-loaded lactobionic acid-modified yolk-shell mesoporous silica nanoparticles were first encapsulated with 4-nitrophenyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzyl carbonate (NBC)-modified Cyt c via boronic ester linkages, and functionalized again with lactobionic acid to further shield Cyt c and confer the selective tumor targeting against liver cancer cells. The key feature in this design is that by taking advantage of the boronic ester linkage, the cytotoxicity of Cyt c capped on the nanoparticle could be temporarily deactivated during blood transportation and rapidly restored upon exposure to the ROS-rich microenvironment within liver cancer cells, thereby simultaneously achieving the protein therapy and stimuli-responsive doxorubicin release. This study presents a novel strategy for the development of tumor-sensitive co-delivery nanoplatforms.

Engineering of a Nanosized Biocatalyst for Combined Tumor Starvation and Low-Temperature Photothermal Therapy.

Tumor hypoxia is one of the major challenges for the treatment of tumors, as it may negatively affect the efficacy of various anticancer modalities. In this study, a tumor-targeted redox-responsive composite biocatalyst is designed and fabricated, which may combine tumor starvation therapy and low-temperature photothermal therapy for the treatment of oxygen-deprived tumors. The nanosystem was prepared by loading porous hollow Prussian Blue nanoparticles (PHPBNs) with glucose oxidase (GOx) and then coating their surface with hyaluronic acid (HA) via redox-cleavable linkage, therefore allowing the nanocarrier to bind specifically with CD44-overexpressing tumor cells while also exerting control over the cargo release profile. The nanocarriers are designed to enhance the efficacy of the hypoxia-suppressed GOx-mediated starvation therapy by catalyzing the decomposition of intratumoral hydroperoxide into oxygen with PHPBNs, and the enhanced glucose depletion by the two complementary biocatalysts may consequently suppress the expression of heat shock proteins (HSPs) after photothermal treatment to reduce their resistance to the PHPBN-mediated low-temperature photothermal therapies.