Noncovalent Polymer‐Gatekeeper in Mesoporous Silica Nanoparticles as a Targeted Drug Delivery Platform

Selective targeting of tumor cells and release of drug molecules inside the tumor microenvironment can reduce the adverse side effects of traditional chemotherapeutics because of the lower dosages required. This can be achieved by using stimuli‐responsive targeted drug delivery systems. In the present work, a robust and simple one‐pot route is developed to synthesize polymer‐gatekeeper mesoporous silica nanoparticles by noncovalent capping of the pores of drug‐loaded nanocontainers with disulfide cross‐linkable polymers. The method offers very high loading efficiency because chemical modification of the mesoporous nanoparticles is not required; thus, the large empty pore volume of pristine mesoporous silica nanoparticles is entirely available to encapsulate drug molecules. Furthermore, the polymer shell can be easily decorated with a targeting ligand for selective delivery to specific cancer cells by subsequent addition of the thiol‐containing ligand molecule. The drug molecules loaded in the nanocontainers can be released by the degradation of the polymer shell in the intracellular reducing microenvironment, which consequentially induces cell death.     

pH/Cathepsin B Hierarchical‐Responsive Nanoconjugates for Enhanced Tumor Penetration and Chemo‐Immunotherapy

An ideal cancer nanomedicine should precisely deliver therapeutics to its intracellular target within tumor cells. However, the multiple biological barriers seriously hinder their delivery efficiency, leading to unsatisfactory therapeutic outcome. Herein, pH/cathepsin B hierarchical‐responsive nanoconjugates (HRNs) are reported to overcome these barriers by sequentially responding to extra‐ and intracellular stimuli in solid tumors for programmed delivery of docetaxel (DTX). The HRNs have stable nanostructures (≈40 nm) in blood circulation for efficient tumor accumulation, while the tumor extracellular acidity induces the rapid dissociation of HRNs into polymer conjugates (≈5 nm), facilitating the deep tumor penetration and cellular internalization. After being trapped into the lysosomes, the conjugates are cleaved by cathepsin B to release bioactive DTX into cytoplasm and inhibit cell proliferation. In addition to the direct inhibition effect, HRNs can trigger the in vivo antitumor immune responses via the immunogenic modulation of tumor cells, activation of dendritic cells (DCs), and generation of cytotoxic T‐cell responses. By employing a combination with α‐PD‐1 (programmed cell death 1) therapy, synergistic antitumor efficacy is achieved in B16 expressing ovalbumin (B16OVA) tumor model. Hence, this strategy demonstrates high efficiency for precise intracellular delivery of chemotherapeutics and provides a potential clinical candidate for cancer chemo‐immunotherapy.     

Real‐Time Imaging Tracking of Engineered Macrophages as Ultrasound‐Triggered Cell Bombs for Cancer Treatment

Cell‐based drug delivery systems are a promising platform for tumor‐targeted therapy due to their high drug‐loading capacities and inherent tumor‐homing abilities. However, the real‐time tracking of these carrier cells and controlled release of the encapsulated drugs are still challenging. Here, ultrasound‐activatable cell bombs are developed by encapsulating doxorubicin (DOX) and phase transformable perfluoropentane (PFP) into hollow mesoporous organosilica nanoparticles (HMONs) to prepare DOX/PFP‐loaded HMONs (DPH), followed by internalization into macrophages (RAW 264.7 cells). The resulting cell bombs (DPH‐RAWs) can maintain viability and actively home to the tumor. Especially, their migration can be tracked in real time using ultrasound due to the vaporization of a small portion of PFP during cell incubation at 37 °C. After accumulation at the tumor site, the further vaporization of remaining PFP can be triggered by a short‐pulsed high intensity focused ultrasound (HIFU) sonication, resulting in the generation of several large microbubbles, which destroys DPH‐RAWs and allows drug release out of these cells. The DPH‐RAWs combined with short‐pulsed HIFU sonication significantly inhibit tumor growth and prolong survival of tumor‐bearing mice. In conclusion, this study provides a new approach to cell‐based drug delivery systems for real‐time tracking of their migration and targeted cancer treatment.     

Surface Engineered Polymersomes for Enhanced Modulation of Dendritic Cells During Cardiovascular Immunotherapy

The principle cause of cardiovascular disease (CVD) is atherosclerosis, a chronic inflammatory condition characterized by immunologically complex fatty lesions within the intima of arterial vessel walls. Dendritic cells (DCs) are key regulators of atherosclerotic inflammation, with mature DCs generating pro‐inflammatory signals within vascular lesions and tolerogenic DCs eliciting atheroprotective cytokine profiles and regulatory T‐cell (Treg) activation. Here, the surface chemistry and morphology of synthetic nanocarriers composed of poly(ethylene glycol)‐b‐poly(propylene sulfide) copolymers to enhance the targeted modulation of DCs by transporting the anti‐inflammatory agent 1,25‐dihydroxyvitamin D3‐(aVD) and ApoB‐100‐derived antigenic peptide P210 are engineered. Polymersomes decorated with an optimized surface display and density for a lipid construct of the P‐D2 peptide, which binds CD11c on the DC surface, significantly enhance the cytosolic delivery and resulting immunomodulatory capacity of aVD in vitro. Weekly low‐dose intravenous administration of DC‐targeted, aVD‐loaded polymersomes significantly inhibit atherosclerotic lesion development in high‐fat‐diet‐fed ApoE^?/? mice. The results validate the key role of DC immunomodulation during aVD‐dependent inhibition of atherosclerosis and demonstrate the therapeutic enhancement and dosage lowering capability of cell‐targeted nanotherapy in the treatment of CVD.     

Targeting of CXCR1 on Osteosarcoma Circulating Tumor Cells and Precise Treatment via Cisplatin Nanodelivery

Metastasis and chemotherapy resistance are the key factors affecting the effectiveness of osteosarcoma (OS) treatments. CXCR1 overexpression is found to be closely related to chemotherapy resistance and anoikis resistance in OS cell subtypes with high metastasis potential. Further study demonstrates that CXCR1 is highly expressed on circulating tumor cell (CTC)‐derived cells with cancer stem cell characteristics. Then, a CXCR1 targeting peptide is designed and synthesized to competitively inhibit the IL‐8/CXCR1 pathway and to improve the cisplatin sensitivity of CTCs. Fluorescence‐labeled magnetic nanoparticles (NPs) with pH‐responsive cisplatin release are fabricated and linked with the CXCR1 targeting peptide (Cis@MFPPC). Results demonstrate that CTC survival could be inhibited effectively by the targeting nanoparticles in vivo. Cis@MFPPC can also inhibit OS growth and pulmonary metastasis in an orthotopic model and patient‐derived tumor xenograft model. This study verifies the clinical significance of CXCR1 as a therapeutic target and provides a drug delivery NP system for precise treatment of OS.     

Co‐delivery of Cell‐permeable Chimeric Apoptosis AVPIR8 Peptide/p53 DNA for Cocktail Therapy

The tetra‐peptide AVPI, derived from the Smac/DIABLO N‐terminal epitope, is able to trigger caspase activation and apoptotic process. However, its clinical value is greatly hampered by the nature of membrane‐impermeability. Herein, the cell‐penetrating chimeric apoptotic peptide of AVPIR₈ is synthesized, of which the apoptosis‐induced AVPI is strategically blended with the cell‐penetrating sequence of octaarginine (R₈). The dual‐functionalized AVPIR₈ is not only potent in inducing apoptosis in tumor cells due to the cell penetration ability, but also is able to work as gene carrier for transfering the tumor suppressor p53 DNA into cells, thus constructing a co‐delivery drug system (AVPIR₈/p53). Such system efficiently promotes apoptosis in cancer cells while sparing normal cells, and its antitumor activity is further significantly enhanced in combination with doxorubicin as cocktail therapy. More importantly, the anticancer efficacy of the cocktail is demonstrated to be able to arrest tumor growth in two animal tumor models (melanoma and cervical cancers), respectively. The chemotherapeutic dose in the AVPIR₈/p53‐based cocktail is significantly reduced by 80%, compared to the monotherapy of doxorubicin. The present results show the promise of the co‐delivered AVPIR₈/p53 as adjuvant therapy for boosting the conventional chemotherapeutics, with a unique benefit of enhanced productive treatment outcomes yet greatly reduced adverse toxicity.     

Immune Complexes Mimicking Synthetic Vaccine Nanoparticles for Enhanced Migration and Cross‐Presentation of Dendritic Cells

The well‐designed activation of dendritic cells (DCs) by enhancing the delivery of antigens and immunostimulatory adjuvants into DCs is a key strategy for efficient cancer immunotherapy. Antigen‐antibody immune complexes (ICs) are known to directly bind to and cross‐link Fc‐gamma receptors (FcγRs) on DCs, which induce enhanced migration of DCs to draining lymph nodes through the up‐regulation of the chemokine receptor CCR7 and cross‐presentation inducing cytotoxic T lymphocyte (CTL) response against tumor antigen. In this study, ICs mimicking synthetic vaccine nanoparticles (NPs) are designed and synthesized by the coating of poly (lactic‐co‐glycolic acid) (PLGA) NPs containing adjuvant (CpG oligodeoxynuleotides (ODNs) as toll‐like receptor 9 ligands) with ovalbumin (OVA) proteins (as model antigens) and by the formation of OVA–OVA antibody ICs. Through the combination of FcγRs‐mediated efficient antigen uptake and CpG ODNs‐based immunostimulation, the secretion of TNF‐α (12.3‐fold), IL‐6 (7.29‐fold), and IL‐12 (11‐fold), homing ability to lymph nodes (7.5‐fold), and cross‐presentation (83.8‐fold IL‐2 secretion) are dramatically increased in DCs treated with PLGA(IC/CpG) NPs. Furthermore, mice vaccinated with DCs treated with PLGA(IC/CpG) NPs induced significant tumor (EG7‐OVA) growth inhibition as well as prolonged survival through CTL‐mediated enhanced cytotoxicity, antigen‐specific responses, and IFN‐γ secretion.     

Biomimetic Copper Sulfide for Chemo‐Radiotherapy: Enhanced Uptake and Reduced Efflux of Nanoparticles for Tumor Cells under Ionizing Radiation

Combined chemo‐radiotherapy is one of most widely applied treatments for clinical cancer therapy. Herein, it is found in this carefully designed study that ionizing radiation (e.g., X‐ray) can significantly increase the cell uptake of many different types of nanoparticles, and meanwhile obviously reduce their efflux. Such a phenomenon, which is not observed for small molecule drug such as doxorubicin (DOX), may be attributed to the X‐ray‐induced cell cycle change and upregulation of Caveolin‐1, a key protein in the caveolin‐dependent endocytosis pathway. Biomimetic copper sulfide nanoparticles, which are synthesized using melanin as the template and functionalized with polyethylene glycol (PEG), are then chosen as a platform for the combined chemo‐radiotherapy. Such CuS@Melanin‐PEG nanoparticles, while being able to load chemotherapeutics (e.g., DOX), can also act as a radiosensitizer to promote X‐ray induced cell apoptosis. In addition, although the overall tumor accumulation of CuS@Melanin‐PEG/DOX post intravenous injection is not significantly changed for tumors exposed to X‐ray, X‐ray radiation can result in obviously increased tumor cell uptake of drug‐loaded nanoparticles, subsequently leading to excellent synergistic antitumor therapeutic effect. A nanoplatform is developed with great performance in chemo‐radiotherapy, as well as uncovers a general synergistic mechanism particularly suitable for nanoparticle‐based chemo‐radiotherapy.     

Dual Targeted Immunotherapy via In Vivo Delivery of Biohybrid RNAi‐Peptide Nanoparticles to Tumor‐Associated Macrophages and Cancer Cells

Lung cancer is associated with very poor prognosis and considered one of the leading causes of death worldwide. Here, highly potent and selective biohybrid RNA interference (RNAi)‐peptide nanoparticles (NPs) are presented that can induce specific and long‐lasting gene therapy in inflammatory tumor associated macrophages (TAMs), via an immune modulation of the tumor milieu combined with tumor suppressor effects. The data here prove that passive gene silencing can be achieved in cancer cells using regular RNAi NPs. When combined with M2 peptide–based targeted immunotherapy that immuno‐modulates TAMs cell population, a synergistic effect and long‐lived tumor eradication can be observed along with increased mice survival. Treatment with low doses of siRNA (ED₅₀ 0.0025–0.01 mg kg^?1) in a multi and long‐term dosing system substantially reduces the recruitment of inflammatory TAMs in lung tumor tissue, reduces tumor size (≈95%), and increases animal survival (≈75%) in mice. The results here suggest that it is likely that the combination of silencing important genes in tumor cells and in their supporting immune cells in the tumor microenvironment, such as TAMs, will greatly improve cancer clinical outcomes.     

A Sequentially Triggered Nanosystem for Precise Drug Delivery and Simultaneous Inhibition of Cancer Growth,Migration, and Invasion

The rational design of cancer‐targeted and bioresponsive drug delivery vehicles can enhance the anticancer efficacy of conventional chemotherapeutics and reduce their adverse side effects. However, the complexity of precise delivery and the ability to trigger drug release in specific tumor sites remain a challenging puzzle. Here, a sequentially triggered nanosystem composed of HER2 antibody with disulfide linkage as a surface decorator (HER2@NPs) is constructed for precise drug delivery and the simultaneous inhibition of cancer growth, migration, and invasion. The nanosystem actively accumulates in cancer cells, undergoes self‐immolative cleavage in response to biological thiols, and is degraded to form small nanoparticles. After internalization by receptor‐mediated endocytosis, the nanoparticles further disassemble under acidic conditions in the presence of lysozymes and cell lysates, leading to sequentially triggered drug release. The released payload triggers overproduction of reactive oxygen species and activates p53 and MAPKs pathways to induce cancer cell apoptosis. Moreover, HER2@NPs markedly suppress the migration and invasion of human bladder cancer cells at nontoxic concentrations. HER2@NPs demonstrate potent in vivo anticancer efficacy, but show no obvious histological damage to the major organs. Taken together, this study provides a valid tactic for the rational design of sequentially triggered nanosystems for precise drug delivery and cancer therapy.     

A Mannosylated,PEGylated Albumin as a Drug Delivery System for the Treatment of Cancer Stroma Cells

Mannose receptors that are expressed on macrophages and fibroblasts in cancer stroma are promising therapeutic targets for cancer treatment. Albumin can be used as a drug carrier in chemotherapeutics due to its accumulation in the tumor tissue by the enhanced permeability and retention effects. A mannosylated albumin was recently developed as a new drug carrier targeting cells that express mannose receptors such as macrophages and fibroblasts in cancer stroma. The mannosylated albumin is specifically distributed to hepatic macrophages in vivo, leading to an extremely short residence time in the blood. Here, a dual-modified albumin, i.e., mannosylated and polyethylene glycosylated (PEGylated) is reported, to improve its blood circulating time and stromal cell targeting. The product efficiently delivers paclitaxel to stromal cells in a mouse melanoma model, thus resulting in the disruption of stromal cells and suppressed tumor growth, which is seven times stronger than that for PEGylated albumin. The findings suggest that the dual-modified albumin has the potential to provide maximal therapeutic efficacies of chemotherapeutics for the treatment of intractable cancer.     

Codelivery of a π–π Stacked Dual Anticancer Drug Combination with Nanocarriers for Overcoming Multidrug Resistance and Tumor Metastasis

The multidrug resistance (MDR) of cancer cells is a major obstacle in cancer chemotherapy and very few strategies are available to overcome it. Here, a new strategy is developed to codeliver a π–π stacked dual anticancer drug combination with an actively targeted, pH‐ and reduction‐sensitive polymer micellar platform for combating multidrug resistance and tumor metastasis. In contrast to other methods, two traditional chemotherapeutics, doxorubicin (DOX) and 10‐hydroxycamptothecin with complex aromatic π–π conjugated structures, are integrated into one drug delivery system via a π–π stacking interaction, which enables the released drugs to evade the recognition of drug pumps due to a slight change in the drug's molecular structure. The micelles exhibit active targeting of DOX‐resistant human breast cancer MCF‐7 cells (MCF‐7/ADR) and have the ability to control the release of the drug in response to the microenvironmental stimuli of tumor cells. As a result, the codelivery of the π–π stacked dual anticancer drug combination displays high therapeutic efficacy in the MCF‐7/ADR tumor model and successfully prevents the lung metastasis of tumor cells. The mechanism underlying the reversal of MDR is investigated, and the results reveal that the synergistic effect of the π–π stacked dual drugs promotes mitochondria‐dependent apoptosis.     

Encapsulating a Hydrophilic Chemotherapeutic into Rod‐Like Nanoparticles of a Genetically Encoded Asymmetric Triblock Polypeptide Improves Its Efficacy

Encapsulating hydrophilic chemotherapeutics into the core of polymeric nanoparticles can improve their therapeutic efficacy by increasing their plasma half‐life, tumor accumulation, and intracellular uptake, and by protecting them from premature degradation. To achieve these goals, a recombinant asymmetric triblock polypeptide (ATBP) that self‐assembles into rod‐shaped nanoparticles, and which can be used to conjugate diverse hydrophilic molecules, including chemotherapeutics, into their core is designed. These ATBPs consist of three segments: a biodegradable elastin‐like polypeptide, a hydrophobic tyrosine‐rich segment, and a short cysteine‐rich segment, that spontaneously self‐assemble into rod‐shaped micelles. Covalent conjugation of a structurally diverse set of hydrophilic small molecules, including a hydrophilic chemotherapeutic—gemcitabine—to the cysteine residues also leads to formation of nanoparticles over a range of ATBP concentrations. Gemcitabine‐loaded ATBP nanoparticles have significantly better tumor regression compared to free drug in a murine cancer model. This simple strategy of encapsulation of hydrophilic small molecules by conjugation to an ATBP can be used to effectively deliver a range of water‐soluble drugs and imaging agents in vivo.     

Tumor‐Microenvironment‐Adaptive Nanoparticles Codeliver Paclitaxel and siRNA to Inhibit Growth and Lung Metastasis of Breast Cancer

Prolonged circulation, specific and effective uptake by tumor cells, and rapid intracellular drug release are three main factors for the drug delivery systems to win the battle against metastatic breast cancer. In this work, a tumor microenvironment‐adaptive nanoparticle co‐loading paclitaxel (PTX) and the anti‐metastasis siRNA targeting Twist is prepared. The nanoparticle consists of a pH‐sensitive core, a cationic shell, and a matrix metalloproteinase (MMP)‐cleavable polyethylene glycol (PEG) corona conjugated via a peptide linker. PEG will be cut away by MMPs at the tumor site, which endows the nanoparticle with smaller particle size and higher positive charge, leading to more efficient cellular uptake in tumor cells and higher intra‐tumor accumulation of both PTX and siRNA in the 4T1 tumor‐bearing mice models compared to the nanoparticles with irremovable PEG. In addition, acid‐triggered drug release in endo/lysosomes is achieved through the pH‐sensitive core. As a result, the MMP/pH dual‐sensitive nanoparticles significantly inhibit tumor growth and pulmonary metastasis. Therefore, this tumor‐microenvironment‐adaptive nanoparticle can be a promising codelivery vector for effective therapy of metastatic breast cancer due to simultaneously satisfying the requirements of long circulating time, efficient tumor cell targeting, and fast intracellular drug release.     

High‐Drug‐Loading Mesoporous Silica Nanorods with Reduced Toxicity for Precise Cancer Therapy against Nasopharyngeal Carcinoma

Nanorod‐based drug delivery systems have attracted great interest because of their enhanced cell internalization capacity and improved drug loading property. Herein, novel mesoporous silica nanorods (MSNRs) with different lengths are synthesized and used as nanocarriers to achieve higher drug loading and anticancer activity. As expected, MSNRs‐based drug delivery systems can effectively enhance the loading capacity of drugs and penetrate into tumor cells more rapidly than spherical nanoparticles due to their greater surface area and trans‐membrane transporting rates. Interestingly, these tailored MSNRs also enhance the cellular uptake of doxorubicin (DOX) in cancer cells, thus significantly enhancing its anticancer efficacy for hundreds of times by inducing of cell apoptosis. Internalized MSNRs‐DOX triggers intracellular reactive oxygen species (ROS) overproduction, which subsequently activates p53 and mitogen‐activated protein kinases (MAPKs) pathways to promote cell apoptosis. MSNRs‐DOX nanosystem also shows prolonged blood circulation time in vivo. In addition, MSNRs‐DOX significantly inhibits in vivo tumor growth in nude mice model and effectively reduced its in vivo toxicity. Therefore, this study provides an effective and safe strategy for designing chemotherapeutic agents for precise cancer therapy.     

Emancipating Target‐Functionalized Carbon Dots from Autophagy Vesicles for a Novel Visualized Tumor Therapy

Killing the tumor cells by a visualized targeting system is a promising strategy with which to achieve high efficiency, low side effects, and a high survival rate for tumor therapy. Here, an autophagy regulation strategy is reported by emancipating target‐functionalized carbon dots from autophagy vesicles for the efficient visualized tumor therapy. The folic acid modified N‐doped carbon dots (FN‐CDs) are selectively endocytosed (specific cellular uptake rate >93.40%) and stably existed in autophagic vacuoles in tumor cells. Next, the autophagic vacuoles are “opened” by the autophagy inhibitors. Released FN‐CDs activate both the intrinsic and extrinsic apoptotic signaling pathway and kill tumor cells efficiently. This method achieves therapeutic effects with high performance in 26 types of tumor cell lines. Animal experiments show that the 30 d survival rate of this therapeutic strategy is much higher than that with traditional drug treatment. Real‐time imaging/monitoring and its effects on the intelligent tumor therapy are also demonstrated based on the stable, strong, green emission from FN‐CDs.     

Multistage Nanovehicle Delivery System Based on Stepwise Size Reduction and Charge Reversal for Programmed Nuclear Targeting of Systemically Administered Anticancer Drugs

The nucleus is the final target of many first‐line chemotherapeutics, but the need to overcome multiple physiological barriers imposes conflicting requirements for size and charge on systemically administered drug delivery systems. Here, an N‐(2‐hydroxypropyl) methacrylamide (HPMA) polymer‐based nanovehicle (PNV) that self‐assembles from anionic HPMA copolymers with charge‐reversal ability and cationic HPMA copolymers with intracellularly detachable subgroups (IDS) is described. The IDS, bearing an anticancer drug and nuclear‐homing cell‐penetrating peptide (R8NLS ligand), is grafted onto the HPMA copolymer via hydrazone linkage. The large, neutrally charged, self‐assembled PNV (≈55 nm) shows good blood persistence and preferential tumor accumulation. After tumoral arrival, the extracellular milieu actuates the disassembly of PNV to linear conjugates (≈10 nm/39 kDa). This first‐stage size reduction exposes R8NLS and allows for deeper tissue penetration and greater cellular internalization. After endocytosis, a second‐stage size reduction occurs when the more acidic endolysosomal pH cleaved the ≈2.4 kDa IDS off the HPMA copolymer backbone and guaranteed the successful nuclear entry via nuclear localization signal assistance. Based on the stepwise size reduction and on‐demand R8NLS exposure, the PNV inhibits growth of HeLa tumors in nude mice by 75%. This work gives important insights into the design of systemic nuclear‐targeted delivery via a multistage size/charge changing way.     

Cancer Cell Membrane‐Coated Gold Nanocages with Hyperthermia‐Triggered Drug Release and Homotypic Target Inhibit Growth and Metastasis of Breast Cancer

The cell‐specific targeting drug delivery and controlled release of drug at the cancer cells are still the main challenges for anti‐breast cancer metastasis therapy. Herein, the authors first report a biomimetic drug delivery system composed of doxorubicin (DOX)‐loaded gold nanocages (AuNs) as the inner cores and 4T1 cancer cell membranes (CMVs) as the outer shells (coated surface of DOX‐incorporated AuNs (CDAuNs)). The CDAuNs, perfectly utilizing the natural cancer cell membranes with the homotypic targeting and hyperthermia‐responsive ability to cap the DAuNs with the photothermal property, can realize the selective targeting of the homotypic tumor cells, hyperthermia‐triggered drug release under the near‐infrared laser irradiation, and the combination of chemo/photothermal therapy. The CDAuNs exhibit a stimuli‐release of DOX under the hyperthermia and a high cell‐specific targeting of the 4T1 cells in vitro. Moreover, the excellent combinational therapy with about 98.9% and 98.5% inhibiting rates of the tumor volume and metastatic nodules is observed in the 4T1 orthotopic mammary tumor models. As a result, CDAuNs can be a promising nanodelivery system for the future therapy of breast cancer.     

Delivery of iPS‐NPCs to the Stroke Cavity within a Hyaluronic Acid Matrix Promotes the Differentiation of Transplanted Cells

Stroke is the leading cause of adult disability with ≈80% being ischemic. Stem cell transplantation has been shown to improve functional recovery. However, the overall survival and differentiation of these cells is still low. The infarct cavity is an ideal location for transplantation as it is directly adjacent to the highly plastic peri‐infarct region. Direct transplantation of cells near the infarct cavity has resulted in low cell viability. Here, neural progenitor cells derived from induce pluripotent stem cells (iPS‐NPC) are delivered to the infarct cavity of stroked mice encapsulated in a hyaluronic acid hydrogel matrix to protect the cells. To improve the overall viability of transplanted cells, each step of the transplantation process is optimized. Hydrogel mechanics and cell injection parameters are investigated to determine their effects on the inflammatory response of the brain and cell viability, respectively. Using parameters that balanced the desire to keep surgery invasiveness minimal and cell viability high, iPS‐NPCs are transplanted to the stroke cavity of mice encapsulated in buffer or the hydrogel. While the hydrogel does not promote stem cell survival one week post‐transplantation, it does promote differentiation of the neural progenitor cells to neuroblasts.     

Transformable Nanoparticle‐Enabled Synergistic Elicitation and Promotion of Immunogenic Cell Death for Triple‐Negative Breast Cancer Immunotherapy

Although cisplatin‐based neoadjuvant chemotherapy is an efficient therapy approach for triple‐negative breast cancer (TNBC), it has dismal prognosis and modestly improved survival benefit. Here, a synergistic immunotherapy of TNBC premised on the elicitation and promotion of immunogenic cell death (ICD) response, through a transformable nanoparticle‐enabled approach for contemporaneous delivery of cisplatin, adjudin, and WKYMVm is reported. The nanoparticles can sequentially respond to matrix metalloproteinases‐2, pH, and glutathione to achieve structural transformation with the advantages of optimal size change, efficient drug delivery, and well‐controlled release. Cisplatin and adjudin can synergistically amplify reactive oxygen species (ROS) cascade and eventually increase the formation of hydrogen peroxide and downstream highly toxic ROS like ?OH, which can elicit ICD response by mechanisms of endoplasmic reticulum stress, apoptotic cell death, and autophagy. WKYMVm can further promote anti‐TNBC immunity by activation of formyl peptide receptor 1 to build stable interactions between dendritic cells and dying cancer cells. Thus, the nanoparticles achieve significant primary tumor regression and pulmonary metastasis inhibition as well as a remarkable survival benefit, with boosting of the innate and adaptive anti‐TNBC immunity.