Hyperbaric Oxygen Potentiates Doxil Antitumor Efficacy by Promoting Tumor Penetration and Sensitizing Cancer Cells

A bioactive nanocomposite integrated specific TAMs target and synergistic TAMs repolarization for effective cancer immunotherapy

Reactive oxygen species (ROS) generated from photosensitizers exhibit great potential for repolarizing immunosuppressive tumor-associated macrophages (TAMs) toward the anti-tumor M1 phenotype, representing a promising cancer immunotherapy strategy. Nevertheless, their effectiveness in eliminating solid tumors is generally limited by the instability and inadequate TAMs-specific targeting of photosensitizers. Here, a novel core-shell integrated nano platform is proposed to achieve a coordinated strategy of repolarizing TAMs for potentiating cancer immunotherapy. Colloidal mesoporous silica nanoparticles (CMSN) are fabricated to encapsulate photosensitizer-Indocyanine Green (ICG) to improve their stability. Then ginseng-derived exosome (GsE) was coated on the surface of ICG/CMSN for targeting TAMs, as well as repolarizing TAMs concurrently, named ICG/CMSN@GsE. As expected, with the synergism of ICG and GsE, ICG/CMSN@GsE exhibited better stability, mild generation of ROS, favorable specificity toward M2-like macrophages, enhancing drug retention in tumors and superior TAMs repolarization potency, then exerted a potent antitumor effect. In vivo, experiment results also confirm the synergistic suppression of tumor growth accompanied by the increased presence of anti-tumor M1-like macrophages and maximal tumor damage. Taken together, by integrating the superiorities of TAMs targeting specificity and synergistic TAMs repolarization effect into a single nanoplatform, ICG/CMSN@GsE can readily serve as a safe and high-performance nanoplatform for enhanced cancer immunotherapy.

Boosting antitumor efficacy of nanoparticles by modulating tumor mechanical microenvironment

Nanoparticles have shown great potential for tumor targeting delivery via enhanced permeability and retention effect. However, the tumor mechanical microenvironment, characterized by dense extracellular matrix (ECM), high tumor stiffness and solid stress, leads to only 0.7% of administered dose accumulating in solid tumors and even fewer (∼0.0014%) reaching tumor cells, limiting the therapeutic efficacy of nanoparticles. Furthermore, the tumor mechanical microenvironment can regulate tumor cell stemness, promote tumor invasion, metastasis and reduce treatment efficacy. In this review, methods detecting the mechanical are introduced. Strategies for modulating the mechanical microenvironment including elimination of dense ECM by physical, chemical and biological methods, disruption of ECM formation, depletion or inhibition of cancer-associated fibroblasts, are then summarized. Finally, prospects and challenges for further clinical applications of mechano-modulating strategies to enhance the therapeutic efficacy of nanomedicines are discussed. This review may provide guidance for the rational design and application of nanoparticles in clinical settings.

Softness-Aided Mild Hyperthermia Boosts Stiff Nanomedicine by Regulating Tumor Mechanics

Aberrant tumor mechanical microenvironment (TMME), featured with overactivated cancer-associated fibroblasts (CAFs) and excessive extracellular matrix (ECM), severely restricts penetration and accumulation of cancer nanomedicines, while mild-hyperthermia photothermal therapy (mild-PTT) has been developed to modulate TMME. However, photothermal agents also encounter the barriers established by TMME, manifesting in limited penetration and heterogeneous distribution across tumor tissues and ending with attenuated efficiency in TMME regulation. Herein, it is leveraged indocyanine green (ICG)-loaded soft nanogels with outstanding deformability, for efficient tumor penetration and uniform distribution, in combination with mild-PTT to achieve potent TMME regulation by inhibiting CAFs and degrading ECM. As a result, doxorubicin (DOX)-loaded stiff nanogels gain greater benefits in tumor penetration and antitumor efficacy than soft counterparts from softness-mediated mild-PTT. This study reveals the crucial role of nanomedicine mechanical properties in tumor distribution and provides a novel strategy for overcoming the barriers of solid tumors with soft deformable nanogels.

Hyperbaric oxygen enhances tumor penetration and accumulation of engineered bacteria for synergistic photothermal immunotherapy

Bacteria-mediated cancer therapeutic strategies have attracted increasing interest due to their intrinsic tumor tropism. However, bacteria-based drugs face several challenges including the large size of bacteria and dense extracellular matrix, limiting their intratumoral delivery efficiency. In this study, we find that hyperbaric oxygen (HBO), a noninvasive therapeutic method, can effectively deplete the dense extracellular matrix and thus enhance the bacterial accumulation within tumors. Inspired by this finding, we modify Escherichia coli Nissle 1917 (EcN) with cypate molecules to yield EcN-cypate for photothermal therapy, which can subsequently induce immunogenic cell death (ICD). Importantly, HBO treatment significantly increases the intratumoral accumulation of EcN-cypate and facilitates the intratumoral infiltration of immune cells to realize desirable tumor eradication through photothermal therapy and ICD-induced immunotherapy. Our work provides a facile and noninvasive strategy to enhance the intratumoral delivery efficiency of natural/engineered bacteria, and may promote the clinical translation of bacteria-mediated synergistic cancer therapy.

Liposomes in the cosmetics: present and outlook

Liposomes are small spherical vesicles composed of phospholipid bilayers capable of encapsulating a variety of ingredients, including water- and oil-soluble compound, which are one of the most commonly used piggybacking and delivery techniques for many active ingredients and different compounds in biology, medicine and cosmetics. With the increasing number of active cosmetic ingredients, the concomitant challenge is to effectively protect, transport, and utilize these substances in a judicious manner. Many cosmetic ingredients are ineffective both topically and systemically when applied to the skin, thus changing the method of delivery and interaction with the skin of the active ingredients is a crucial step toward improving their effectiveness. Liposomes can improve the delivery of active ingredients to the skin, enhance their stability, and ultimately, improve the efficacy of cosmetics and and pharmaceuticals. In this review, we summarized the basic properties of liposomes and their recent advances of functionalities in cosmetics and and pharmaceuticals. Also, the current state of the art in the field is discussed and the prospects for future research areas are highlighted. We hope that this review will provide ideas and inspiration on the application and development of cosmetics and pharmaceuticals.

Hyperbaric Oxygen Boosts Antitumor Efficacy of Copper-Diethyldithiocarbamate Nanoparticles against Pancreatic Ductal Adenocarcinoma by Regulating Cancer Stem Cell Metabolism

Cuproptosis-based cancer nanomedicine has received widespread attention recently. However, cuproptosis nanomedicine against pancreatic ductal adenocarcinoma (PDAC) is severely limited by cancer stem cells (CSCs), which reside in the hypoxic stroma and adopt glycolysis metabolism accordingly to resist cuproptosis-induced mitochondria damage. Here, we leverage hyperbaric oxygen (HBO) to regulate CSC metabolism by overcoming tumor hypoxia and to augment CSC elimination efficacy of polydopamine and hydroxyethyl starch stabilized copper-diethyldithiocarbamate nanoparticles (CuET@PH NPs). Mechanistically, while HBO and CuET@PH NPs inhibit glycolysis and oxidative phosphorylation, respectively, the combination of HBO and CuET@PH NPs potently suppresses energy metabolism of CSCs, thereby achieving robust tumor inhibition of PDAC and elongating mice survival importantly. This study reveals novel insights into the effects of cuproptosis nanomedicine on PDAC CSC metabolism and suggests that the combination of HBO with cuproptosis nanomedicine holds significant clinical translation potential for PDAC patients.

Enhancing drug penetration in solid tumors via nanomedicine: Evaluation models, strategies and perspectives

Effective tumor treatment depends on optimizing drug penetration and accumulation in tumor tissue while minimizing systemic toxicity. Nanomedicine has emerged as a key solution that addresses the rapid clearance of free drugs, but achieving deep drug penetration into solid tumors remains elusive. This review discusses various strategies to enhance drug penetration, including manipulation of the tumor microenvironment, exploitation of both external and internal stimuli, pioneering nanocarrier surface engineering, and development of innovative tactics for active tumor penetration. One outstanding strategy is organelle-affinitive transfer, which exploits the unique properties of specific tumor cell organelles and heralds a potentially transformative approach to active transcellular transfer for deep tumor penetration. Rigorous models are essential to evaluate the efficacy of these strategies. The patient-derived xenograft (PDX) model is gaining traction as a bridge between laboratory discovery and clinical application. However, the journey from bench to bedside for nanomedicines is fraught with challenges. Future efforts should prioritize deepening our understanding of nanoparticle-tumor interactions, re-evaluating the EPR effect, and exploring novel nanoparticle transport mechanisms.

Amplified Targeted Drug Delivery Independent of Target Number through Alternative Administration of Two Matched Nanoparticles

Targeting nanoparticles (NPs) based on the specific binding of ligands with molecular targets provides a promising tool for tissue-selective drug delivery. However, the number of molecular targets on the cell surface is limited, hindering the number of NPs that can bind and, thus, limiting the therapeutic outcome. Although several strategies have been developed to enhance drug delivery, such as enhancing drug loading and circulation time or increasing the enhanced permeability and retention effect of nanocarriers, none have resolved this issue. Herein, we designed a simple method for amplified and targeted drug delivery using two matched NPs. One NP was aptamer-functionalized to specifically bind to target cells, while the other was aptamer-complementary DNA-functionalized to specifically bind to aptamer-NPs. Alternate administration of the two matched NPs enables their continuous accumulation in the disease site despite their limited molecular targets. As a proof of concept, the method was tested in a breast cancer model and significantly enhanced chemotherapy of tumor cells in vitro and in vivo. The potential applications of this method in a brain injury model were also demonstrated. Overall, the study describes a method for amplified targeted drug delivery independent of the target number.

Advances in hyperbaric oxygen to promote immunotherapy through modulation of the tumor microenvironment

Hyperbaric oxygen therapy is a relatively safe treatment method that has been used for a long time in the clinic. It has been proven that it can enhance the sensitivity of radiotherapy and photodynamic therapy for cancer. However, there are few studies on hyperbaric oxygen and immunotherapy. In this article, we summarize that hyperbaric oxygen therapy regulates the tumor microenvironment through various pathways such as improving tumor hypoxia, targeting hypoxia-inducing factors, and generating reactive oxygen species. The change in the tumor microenvironment ultimately affects the curative effect of immunotherapy. Therefore, hyperbaric oxygen can influence immunotherapy by regulating the tumor microenvironment, providing a direction for the future development of immunotherapy.

Low-Cost, High-Pressure-Synthesized Oxygen-Entrapping Materials to Improve Treatment of Solid Tumors

Tumor hypoxia drives resistance to many cancer therapies, including radiotherapy and chemotherapy. Methods that increase tumor oxygen pressures, such as hyperbaric oxygen therapy and microbubble infusion, are utilized to improve the responses to current standard-of-care therapies. However, key obstacles remain, in particular delivery of oxygen at the appropriate dose and with optimal pharmacokinetics. Toward overcoming these hurdles, gas-entrapping materials (GeMs) that are capable of tunable oxygen release are formulated. It is shown that injection or implantation of these materials into tumors can mitigate tumor hypoxia by delivering oxygen locally and that these GeMs enhance responsiveness to radiation and chemotherapy in multiple tumor types. This paper also demonstrates, by comparing an oxygen (O2 )-GeM to a sham GeM, that the former generates an antitumorigenic and immunogenic tumor microenvironment in malignant peripheral nerve sheath tumors. Collectively the results indicate that the use of O2 -GeMs is promising as an adjunctive strategy for the treatment of solid tumors.

LncRNA SPRY4‑IT1 is upregulated and promotes the proliferation of prostate cancer cells under hypoxia in vitro

The incidence and mortality rate of prostate cancer are among the highest for all cancers worldwide; this disease has a high cancer mortality rate in males, following lung cancer. Sprouty4-intron 1 (SPRY4-IT1) has been shown to play a variety of roles in tumors. Our previous study demonstrated that SPRY4-IT1 sponges microRNA-101-3p to promote the proliferation and metastasis of bladder cancer cells by upregulating enhancer of zeste homolog 2 expression; however, the role of SPRY4-IT1 in prostate cancer has not been fully established. In the present study, the expression levels, effects and mechanism of action of SPRY4-IT1 were investigated in prostate cancer tissues and cell lines using reverse transcription-quantitative PCR, western blotting, Cell Counting Kit-8 and flow cytometry assays. The results indicated that SPRY4-IT1 expression was upregulated in prostate cancer tissues and cell lines. Furthermore, hypoxia increased the expression levels of SPRY4-IT1 in prostate cancer cells. Knockdown of SPRY4-IT1 expression led to S-phase arrest, decreased expression levels of the cell cycle-associated proteins CDK2 and cyclin D1. AKT phosphorylation was also reduced by SPRY4-IT1 knockdown. In summary, the findings indicate the elevation of SPRY4-IT1 expression in prostate cancer. Under hypoxic conditions in vitro, SPRY4-IT1 overexpression promoted prostate cancer cell proliferation via a mechanism involving regulation of the cell cycle and the PI3K/AKT signaling pathway. Therefore, it may provide a basis for the development of targeted therapies.

Nanotechnological strategies to increase the oxygen content of the tumor

Hypoxia is a negative prognostic indicator of solid tumors, which not only changes the survival state of tumors and increases their invasiveness but also remarkably reduces the sensitivity of tumors to treatments such as radiotherapy, chemotherapy and photodynamic therapy. Thus, developing therapeutic strategies to alleviate tumor hypoxia has recently been considered an extremely valuable target in oncology. In this review, nanotechnological strategies to elevate oxygen levels in tumor therapy in recent years are summarized, including (I) improving the hypoxic tumor microenvironment, (II) oxygen delivery to hypoxic tumors, and (III) oxygen generation in hypoxic tumors. Finally, the challenges and prospects of these nanotechnological strategies for alleviating tumor hypoxia are presented.

Hypoxia signaling in cancer: Implications for therapeutic interventions

Hypoxia is a persistent physiological feature of many different solid tumors and a key driver of malignancy, and in recent years, it has been recognized as an important target for cancer therapy. Hypoxia occurs in the majority of solid tumors due to a poor vascular oxygen supply that is not sufficient to meet the needs of rapidly proliferating cancer cells. A hypoxic tumor microenvironment (TME) can reduce the effectiveness of other tumor therapies, such as radiotherapy, chemotherapy, and immunotherapy. In this review, we discuss the critical role of hypoxia in tumor development, including tumor metabolism, tumor immunity, and tumor angiogenesis. The treatment methods for hypoxic TME are summarized, including hypoxia-targeted therapy and improving oxygenation by alleviating tumor hypoxia itself. Hyperoxia therapy can be used to improve tissue oxygen partial pressure and relieve tumor hypoxia. We focus on the underlying mechanisms of hyperoxia and their impact on current cancer therapies and discuss the prospects of hyperoxia therapy in cancer treatment.

Tumor microenvironment-regulating nanomedicine design to fight multi-drug resistant tumors

The tumor microenvironment (TME) is a very cunning system that enables tumor cells to escape death post-traditional antitumor treatments through the comprehensive effect of different factors, thereby leading to drug resistance. Deep insights into TME characteristics and tumor resistance encourage the construction of nanomedicines that can remodel the TME against drug resistance. Tremendous interest in combining TME-regulation measurement with traditional tumor treatment to fight multidrug-resistant tumors has been inspired by the increasing understanding of the role of TME reconstruction in improving the antitumor efficiency of drug-resistant tumor therapy. This review focuses on the underlying relationships between specific TME characteristics (such as hypoxia, acidity, immunity, microorganisms, and metabolism) and drug resistance in tumor treatments. The exciting antitumor activities strengthened by TME regulation are also discussed in-depth, providing solutions from the perspective of nanomedicine design. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Hydroxyethyl starch-folic acid conjugates stabilized theranostic nanoparticles for cancer therapy

Small molecular prodrug-based nanomedicines with high drug-loading efficiency and tumor selectivity have attracted great attention for cancer therapy against solid tumors, including triple negative breast cancers (TNBC). However, abnormal tumor mechanical microenvironment (TMME) severely restricts antitumor efficacy of prodrug nanomedicines by limiting drug delivery and fostering cancer stem cells (CSCs). Herein, we employed carbamate disulfide bridged doxorubicin dimeric prodrug as pharmaceutical ingredient, marketed IR780 iodide as photothermal agent, and biocompatible hydroxyethyl starch-folic acid conjugates as amphiphilic surfactant to prepare a theranostic nanomedicine (FDINs), which could actively target at TNBC 4T1 tumor tissues and achieve reduction-responsive drug release with high glutathione concentration in cancer cells and CSCs. Importantly, in addition to directly causing damage to cancer cells and sensitizing chemotherapy, FDINs-mediated photothermal effect regulates aberrant TMME via reducing cancer associated fibroblasts and depleting extracellular matrix proteins, thereby normalizing intratumor vessel structure and function to facilitate drug and oxygen delivery. Furthermore, FDINs potently eliminate CSCs by disrupting unique CSCs niche and consuming intracellular GSH in CSCs. As a result, FDINs significantly suppress tumor growth in both subcutaneous and orthotopic 4T1 tumors. This study provides novel insights on rational design of prodrug nanomedicines for superior therapeutic effect against stroma- and CSCs-rich solid malignancies.

Preparation of multifunctional mesoporous SiO2nanoparticles and anti-tumor action

A targeted drug delivery system was developed to accumulate specific drugs around tumor cells based on the redox, temperature, and enzyme synergistic responses of mesoporous silica nanoparticles. Mesoporous silica nanoparticles (MSN-NH2) and Doxorubicin (DOX) for tumor therapy were prepared and loaded into the pores of MSN- NH2 to obtain DOX@MSN(DM NPs). Hyaluronic acid (HA) was used as the backbone and disulfide bond was used as the linker arm to graft carboxylated poly (N-isopropylacrylamide)(PNIPAAm-COOH) to synthesize the macromolecular copolymer (HA-SS-PNIPAAm), which was modified to DM NPs with capped ends to obtain the nano-delivery system DOX@MSN@HA-SS-PNIPAAm(DMHSP NPs), and a control formulation was prepared in a similar way. DMHSP NPs specifically entered tumor cells via CD44 receptor-mediated endocytosis; the high GSH concentration (10 mM) of cells severed the disulfide bonds, the hyaluronidase sheared the capped HA to open the pores, and increased tumor microenvironment temperature due to immune response can trigger the release of encapsulated drugs in thermosensitive materials.In vitroandin vivoantitumor and hemolysis assays showed that DMHSP NPs can accurately target hepatocellular carcinoma cells with a good safety profile and have synergistic effects, which meant DMHSP NPs had great potential for tumor therapy.

Effects of Hyperbaric Oxygen Preconditioning on Doxorubicin Cardiorespiratory Toxicity

Cardiorespiratory dysfunction resulting from doxorubicin (DOX) chemotherapy treatment is a debilitating condition affecting cancer patient outcomes and quality of life. DOX treatment promotes cardiac and respiratory muscle pathology due to enhanced reactive oxygen species (ROS) production, mitochondrial dysfunction and impaired muscle contractility. In contrast, hyperbaric oxygen (HBO) therapy is considered a controlled oxidative stress that can evoke a substantial and sustained increase in muscle antioxidant expression. This HBO-induced increase in antioxidant capacity has the potential to improve cardiac and respiratory (i.e., diaphragm) muscle redox balance, preserving mitochondrial function and preventing muscle dysfunction. Therefore, we determined whether HBO therapy prior to DOX treatment is sufficient to enhance muscle antioxidant expression and preserve muscle redox balance and cardiorespiratory muscle function. To test this, adult female Sprague Dawley rats received HBO therapy (2 or 3 atmospheres absolute (ATA), 100% O₂, 1 h/day) for 5 consecutive days prior to acute DOX treatment (20 mg/kg i.p.). Our data demonstrate that 3 ATA HBO elicits a greater antioxidant response compared to 2 ATA HBO. However, these effects did not correspond with beneficial adaptations to cardiac systolic and diastolic function or diaphragm muscle force production in DOX treated rats. These findings suggest that modulating muscle antioxidant expression with HBO therapy is not sufficient to prevent DOX-induced cardiorespiratory dysfunction.

Rational Modulation of BODIPY Photosensitizers to Design Metal-Organic Framework-Based NIR Nanocomposites for High-Efficiency Photodynamic Therapy in a Hypoxic Environment

Photodynamic therapy (PDT) is a promising noninvasive treatment that has drawn great attention. However, the hypoxic environment in tumors seriously limits the therapeutic effect of oxygen-dependent chemicals and PDT. Herein, a versatile nanocomposite DF-BODIPY@ZIF-8 with oxygen-generating ability was developed based on zeolitic imidazolate framework-8 (ZIF-8) by loading the near-infrared photosensitizer DF-BODIPY to overcome hypoxia-induced drug resistance in cancer therapy. ZIF-8 can catalyze the decomposition of hydrogen peroxide in tumors and increase the dissolved oxygen concentration, resulting in a significant improvement in PDT efficacy. Additionally, we found that enhancing the electronegativity of substituents can effectively reduce the energy level difference (ΔE_st) between the minimum singlet state (S₁) and the lowest triplet state (T₁), leading to the enhancement of the singlet oxygen quantum yield. In vitro experiments suggested that DF-BODIPY@ZIF-8 indeed had a higher singlet oxygen quantum yield and better tumor cell phototoxicity than free DF-BODIPY. In vivo experiments also demonstrated that DF-BODIPY@ZIF-8 could effectively eliminate 4T1 tumors under light irradiation. Thus, we conclude that increasing the electronegativity of substituents and introducing a ZIF-8 material can effectively improve the singlet oxygen quantum yield and overcome the hypoxia limitations for high-efficiency PDT.

The role of imaging in targeted delivery of nanomedicine for cancer therapy

Nanomedicines overcome the pharmacokinetic limitations of traditional drug formulations and have promising prospect in cancer treatment. However, nanomedicine delivery in vivo is still facing challenges from the complex physiological environment. For the purpose of effective tumor therapy, they should be designed to guarantee the five features principle, including long blood circulation, efficient tumor accumulation, deep matrix penetration, enhanced cell internalization and accurate drug release. To ensure the excellent performance of the designed nanomedicine, it would be better to monitor the drug delivery process as well as the therapeutic effects by real-time imaging. In this review, we summarize strategies in developing nanomedicines for efficiently meeting the five features of drug delivery, and the role of several imaging modalities (fluorescent imaging (FL), magnetic resonance imaging (MRI), computed tomography (CT), photoacoustic imaging (PAI), positron emission tomography (PET), and electron microscopy) in tracing drug delivery and therapeutic effect in vivo based on five features principle.

Hyperbaric oxygen facilitates teniposide-induced cGAS-STING activation to enhance the antitumor efficacy of PD-1 antibody in HCC

BACKGROUND

Emerging evidence indicates that the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) axis plays a pivotal role in intrinsic antitumor immunity. Previous studies demonstrate that the conventional chemotherapy agent, teniposide, effectively promotes the therapeutic efficacy of programmed cell death protein-1 antibody (PD-1 Ab) through robust cGAS-STING activation. Unfortunately, the cGAS expression of tumor cells is reported to be severely suppressed by the hypoxic status in solid tumor. Clinically, enhancing chemotherapy-induced, DNA-activated tumor STING signaling by alleviating tumor hypoxia might be one possible direction for improving the currently poor response rates of patients with hepatocellular carcinoma (HCC) to PD-1 Ab.

METHODS

Teniposide was first screened out from several chemotherapy drugs according to their potency in inducing cGAS-STING signaling in human HCC cells. Teniposide-treated HCC cells were then cultured under hypoxia, normoxia or reoxygenation condition to detect change in cGAS-STING signaling. Next, oxaliplatin/teniposide chemotherapy alone or combined with hyperbaric oxygen (HBO) therapy was administered on liver orthotopic mouse tumor models, after which the tumor microenvironment (TME) was surveyed. Lastly, teniposide alone or combined with HBO was performed on multiple mouse tumor models and the subsequent anti-PD-1 therapeutic responses were observed.

RESULTS

Compared with the first-line oxaliplatin chemotherapy, teniposide chemotherapy induced stronger cGAS-STING signaling in human HCC cells. Teniposide-induced cGAS-STING activation was significantly inhibited by hypoxia inducible factor 1α in an oxygen-deficient environment in vitro and the inhibition was rapidly removed via effective reoxygenation. HBO remarkably enhanced the cGAS-STING-dependent tumor type Ⅰ interferon and nuclear factor kappa-B signaling induced by teniposide in vivo, both of which contributed to the activation of dendritic cells and subsequent cytotoxic T cells. Combined HBO with teniposide chemotherapy improved the therapeutic effect of PD-1 Ab in multiple tumor models.

CONCLUSIONS

By combination of two therapies approved by the Food and Drug Administration, we safely stimulated an immunogenic, T cell-inflamed HCC TME, leading to further sensitization of tumors to anti-PD-1 immunotherapy. These findings might enrich therapeutic strategies for advanced HCC andwe can attempt to improve the response rates of patients with HCC to PD-1 Ab by enhancing DNA-activated STING signaling through effective tumor reoxygenation.

Extracellular vesicles for improved tumor accumulation and penetration

Extracellular vesicles (EVs), including microparticles and exosomes, have emerged as potential tools for tumor targeting delivery during the past years. Recently, mass of strategies are applied to assist EVs to accumulate and penetrate into deep tumor sites. In this review, EVs from different cells with unique innate characters and engineered approaches (e.g. chemical engineering, genetical engineering and biomimetic engineering) as drug delivery systems to enhance tumor accumulation and penetration are summarized. Meanwhile, efficient biological function modulation (e.g. extracellular matrix degradation, mechanical property regulation and transcytosis) is introduced to facilitate tumor accumulation and penetration of EVs. Finally, the prospects and challenges on further clinical applications of EVs are discussed.

Implications of Hyperoxia over the Tumor Microenvironment: An Overview Highlighting the Importance of the Immune System

Hyperoxia is used in order to counteract hypoxia effects in the TME (tumor microenvironment), which are described to boost the malignant tumor phenotype and poor prognosis. The reduction of tumor hypoxic state through the formation of a non-aberrant vasculature or an increase in the toxicity of the therapeutic agent improves the efficacy of therapies such as chemotherapy. Radiotherapy efficacy has also improved, where apoptotic mechanisms seem to be implicated. Moreover, hyperoxia increases the antitumor immunity through diverse pathways, leading to an immunopermissive TME. Although hyperoxia is an approved treatment for preventing and treating hypoxemia, it has harmful side-effects. Prolonged exposure to high oxygen levels may cause acute lung injury, characterized by an exacerbated immune response, and the destruction of the alveolar-capillary barrier. Furthermore, under this situation, the high concentration of ROS may cause toxicity that will lead not only to cell death but also to an increase in chemoattractant and proinflammatory cytokine secretion. This would end in a lung leukocyte recruitment and, therefore, lung damage. Moreover, unregulated inflammation causes different consequences promoting tumor development and metastasis. This process is known as protumor inflammation, where different cell types and molecules are implicated; for instance, IL-1β has been described as a key cytokine. Although current results show benefits over cancer therapies using hyperoxia, further studies need to be conducted, not only to improve tumor regression, but also to prevent its collateral damage.

Rational Design of Nanotherapeutics Based on the Five Features Principle for Potent Elimination of Cancer Stem Cells

Cancer stem cells (CSCs), also known as tumor initiating cells or tumor repopulating cells, which comprise only a small fraction of tumor, have received tremendous attention during the past two decades, as they are considered as the ringleader for initiation and progression of tumors, therapy resistance, metastasis, and recurrence in the clinic. Hence, eradicating CSCs is critical for successful cancer treatment. To that end, various CSC-targeting therapeutic agents have been pursued. However, these CSC-specific drugs are ineffective toward bulk cancer cells. Furthermore, these anti-CSC drugs not only eradicate CSCs but also affect conventional stem cells in normal organs or tissues. By virtue of the enhanced permeability and retention (EPR) effect, nanomaterial drug delivery systems (NDDSs) passively accumulate in tumor tissues, thereby alleviating severe side effects toward normal viscera. NDDSs can be further functionalized with CSC-specific binding molecules to promote targeted drug delivery toward CSCs. Moreover, NDDSs have unique advantages in encapsulating CSC-specific drugs and cytotoxic agents, realizing synchronized killing of CSCs and bulk cancer cells both temporally and spatially. For these reasons, leveraging nanotherapeutic strategies to target CSCs has gained tremendous attention recently.Some ten years ago, we summarized five basic features of efficient nanotherapeutics (the five features principle), which consist of long circulation, tumor accumulation, deep penetration, cellular internalization, and drug release. Based on this design rationale, we constructed several NDDSs, including nanogels with adaptive hydrophobicity, CSC-derived microparticles with tailored softness, and tumor exosome sheathed porous silicon biomimetic nanoparticles, for targeted drug delivery to tumor. To our astonishment, these NDDSs that possess the five basic features achieve decent drug delivery efficiency toward not only bulk tumor cells but more importantly CSCs. Consequently, such nanotherapeutics as-designed based on the five features principle are potent in eradicating CSCs, even with only cytotoxic drugs, for instance, doxorubicin. Furthermore, commercialized nanomedicines, such as Doxil and Abraxane, can be endowed with these five basic features by hyperbaric oxygen therapy and therefore achieve outstanding drug delivery efficiency, potent CSC elimination, and efficient cancer therapy. These studies suggest that intractable CSCs can be tackled with a material-based approach, highlight the critical role of the five features principle in designing effective nanotherapeutics, and pinpoint the significance of drug delivery efficiency in eliminating CSCs and bulk cancer cells.

Tumor-Acidity and Bioorthogonal Chemistry-Mediated On-Site Size Transformation Clustered Nanosystem to Overcome Hypoxic Resistance and Enhance Chemoimmunotherapy

Hypoxia, a common feature of most solid tumors, causes severe tumor resistance to chemotherapy and immunotherapy. Herein, a tumor-acidity and bioorthogonal chemistry-mediated on-site size transformation clustered nanosystem is designed to overcome hypoxic resistance and enhance chemoimmunotherapy. The nanosystem utilized the tumor-acidity responsive group poly(2-azepane ethyl methacrylate) with a rapid response rate and highly efficient bioorthogonal click chemistry to form large-sized aggregates in tumor tissue to enhance accumulation and retention. Subsequently, another tumor-acidity responsive group of the maleic acid amide with a slow response rate was cleaved allowing the aggregates to slowly dissociate into ultrasmall nanoparticles with better tumor penetration ability for the delivery of doxorubicin (DOX) and nitric oxide (NO) to a hypoxic tumor tissue. NO can reverse a hypoxia-induced DOX resistance and boost the antitumor immune response through a reprogrammed tumor immune microenvironment. This tumor-acidity and bioorthogonal chemistry-mediated on-site size transformation clustered nanosystem not only helps to counteract a hypoxia-induced chemoresistance and enhance antitumor immune responses but also provides a general drug delivery strategy for enhanced tumor accumulation and penetration.

Engineering nanomedicines to inhibit hypoxia-inducible Factor-1 for cancer therapy

Hypoxia-inducible factor-1 (HIF-1), an essential promoter of tumor progression, has attracted increasing attention as a therapeutic target. In addition to hypoxic cellular conditions, HIF-1 activation can be triggered by cancer treatment, which causes drug tolerance and therapeutic failure. To date, a series of effective strategies have been explored to suppress HIF-1 function, including silencing the HIF-1α gene, inhibiting HIF-1α protein translation, degrading HIF-1α protein, and inhibiting HIF-1 transcription. Furthermore, nanoparticle-based drug delivery systems have been widely developed to improve the stability and pharmacokinetics of HIF-1 inhibitors or achieve HIF-1-targeted combination therapies as a nanoplatform. In this review, we summarize the current literature on nanomedicines targeting HIF-1 to combat cancer and discuss their potential for future development.

Light-responsive nanodrugs co-self-assembled from a PEG-Pt(IV) prodrug and doxorubicin for reversing multi-drug resistance in the chemotherapy process of hypoxic solid tumors

The hypoxia-induced multidrug resistance (MDR) often develops in the chemotherapy process of most anticancer drugs (e.g., doxorubicin, DOX) and results in the treatment failure in clinic. Herein, a PEG-Pt(IV) prodrug...

Autocatalytic oncotherapy nanosystem with glucose depletion for cascade amplification of hypoxia-activated chemotherapy and H2O2-dependent chemodynamic therapy

Hypoxia-activated prodrug is an appealing oncotherapy strategy, but limited by insufficient tumor hypoxia. Moreover, standalone prodrug fails to treat tumor satisfactorily due to tumor complexity. Herein, a nanosystem (TPZ@FeMSN-GOX) was...

Chemical Biology Toolbox to Overcome Hypoxic Tumor Microenvironment of Photodynamic Therapy: A Review

Cancer is currently a disease that seriously threatens human health. Over the past few decades, researchers have continued to find ways to cure cancer. Currently, the most commonly used clinical...

A smart O2-generating nanocarrier optimizes drug transportation comprehensively for chemotherapy improving

Drug transportation is impeded by various barriers in the hypoxic solid tumor, resulting in compromised anticancer efficacy. Herein, a solid lipid monostearin (MS)-coated CaO₂/MnO₂ nanocarrier was designed to optimize doxorubicin (DOX) transportation comprehensively for chemotherapy enhancement. The MS shell of nanoparticles could be destroyed selectively by highly-expressed lipase within cancer cells, exposing water-sensitive cores to release DOX and produce O₂. After the cancer cell death, the core-exposed nanoparticles could be further liberated and continue to react with water in the tumor extracellular matrix (ECM) and thoroughly release O₂ and DOX, which exhibited cytotoxicity to neighboring cells. Small DOX molecules could readily diffuse through ECM, in which the collagen deposition was decreased by O₂-mediated hypoxia-inducible factor-1 inhibition, leading to synergistically improved drug penetration. Concurrently, DOX-efflux-associated P-glycoprotein was also inhibited by O₂, prolonging drug retention in cancer cells. Overall, the DOX transporting processes from nanoparticles to deep tumor cells including drug release, penetration, and retention were optimized comprehensively, which significantly boosted antitumor benefits.

Hyperbaric Oxygen Boosts PD-1 Antibody Delivery and T Cell Infiltration for Augmented Immune Responses Against Solid Tumors

Aberrant mechanical properties and immunosuppression are the two key factors that limit the antitumor efficacy of T cell immune checkpoint blockade inhibitors, e.g., programmed cell death-1 antibody (PD-1 Ab), against solid tumors in the clinic. This study leverages hyperbaric oxygen (HBO) for the first time to address these two issues and reports the PD-1-Ab-mediated immune responses against various stroma-rich solid malignancies. The results demonstrate that HBO promoted PD-1 Ab delivery and T cells infiltration into tumor parenchyma by depleting the extracellular matrix's main components, such as collagen and fibronectin. Furthermore, HBO disrupts hypoxia-mediated immunosuppression and helps PD-1 Ab trigger robust cytotoxic T lymphocytes and long-lasting immunological memory to inhibit tumor relapses. Such enhanced immune responses are effective in solid tumors from rodents and the cancer cells from hepatocellular carcinoma patients. The results illustrate that HBO bolsters antitumor efficacy of PD-1 Ab, and the HBO-PD-1 Ab combination is a promising stroma-rich solid tumors' treatment in the clinic.

Hyperbaric Oxygen Therapy Represses the Warburg Effect and Epithelial-Mesenchymal Transition in Hypoxic NSCLC Cells via the HIF-1α/PFKP Axis

BACKGROUND

Tumor cells initiate hypoxia-induced mechanisms to fuel cell proliferation, invasion, and metastasis, largely mediated by low O2-responsive Hypoxia-Inducible Factor 1 Alpha (HIF-1α). Therefore, hyperbaric oxygen therapy (HBO) is now being studied in cancer patients, but its impact upon non-small-cell lung cancer (NSCLC) cell metabolism remains uncharacterized.

METHODS

We employed the NSCLC cell lines A549 and H1299 for in vitro studies. Glucose uptake, pyruvate, lactate, and adenosine triphosphate (ATP) assays were used to assess aerobic glycolysis (Warburg effect). A quantitative glycolytic flux model was used to analyze the flux contributions of HIF-1α-induced glucose metabolism genes. We used a Lewis lung carcinoma (LLC) murine model to measure lung tumorigenesis in C57BL/6J mice.

RESULTS

HBO suppressed hypoxia-induced HIF-1α expression and downstream HIF-1α signaling in NSCLC cells. One HIF-1α-induced glucose metabolism gene-Phosphofructokinase, Platelet (PFKP)-most profoundly enhanced glycolytic flux under both low- and high-glucose conditions. HBO suppressed hypoxia-induced PFKP transactivation and gene expression via HIF-1α downregulation. HBO's suppression of the Warburg effect, suppression of hyperproliferation, and suppression of epithelial-to-mesenchymal transition (EMT) in hypoxic NSCLC cell lines is mediated by the HIF-1α/PFKP axis. In vivo, HBO therapy inhibited murine LLC lung tumor growth in a Pfkp-dependent manner.

CONCLUSIONS

HBO's repression of the Warburg effect, repression of hyperproliferation, and repression of EMT in hypoxic NSCLC cells is dependent upon HIF-1α downregulation. HIF-1α's target gene PFKP functions as a central mediator of HBO's effects in hypoxic NSCLC cells and may represent a metabolic vulnerability in NSCLC tumors.

Albumin-Templated Bi2Se3-MnO2 Nanocomposites with Promoted Catalase-Like Activity for Enhanced Radiotherapy of Cancer

Novel and effective radiosensitizers that can enhance radiosensitivity of tumor tissues and increase the local radiation dose are highly desirable. In this work, templated by bovine serum albumin (BSA), Bi2Se3-MnO2 nanocomposites (Bi2Se3-MnO2@BSA) were fabricated via biomineralization, while Bi2Se3 nanodots act as radiosensitizers to increase the local radiation dosage because of their strong X-ray attenuation ability, and MnO2 with catalase-like activity can increase the oxygen concentration in tumors by triggering the decomposition of tumor endogenous H2O2 so as to improve the hypoxia-associated radioresistance of tumors. Owing to the interaction of the two components in the interface, Bi2Se3-MnO2@BSA showed promoted catalytic activity compared to MnO2@BSA, favoring tumor radiotherapy (RT) sensitization. BSA templating enabled the nanocomposites with high colloidal stability and biocompatibility as well as satisfactory tumor targeting both in vitro and in vivo; thus, an enhanced RT efficacy was obtained. Moreover, the proposed Bi2Se3-MnO2@BSA exhibited excellent performances in computerized tomography and magnetic resonance imaging. Thus, this work provides a tumor microenvironment-responsive multifunctional theranostic nanoagent with an improved performance for imaging-guided tumor RT sensitization.

Quantum Disordered State of Magnetic Charges in Nanoengineered Honeycomb Lattice

A quantum magnetic state due to magnetic charges is never observed, even though they are treated as quantum mechanical variables in theoretical calculations. Here, the occurrence of a novel quantum disordered state of magnetic charges in a nanoengineered magnetic honeycomb lattice of ultra-small connecting elements is demonstrated. The experimental research, performed using spin resolved neutron scattering, reveals a massively degenerate ground state, comprised of low integer and energetically forbidden high integer magnetic charges, that manifests cooperative paramagnetism at low temperature. The system tends to preserve the degenerate configuration even under large magnetic field application. It exemplifies the robustness of disordered correlation of magnetic charges in a 2D honeycomb lattice. The realization of quantum disordered ground state elucidates the dominance of exchange energy, which is enabled due to the nanoscopic magnetic element size in nanoengineered honeycomb. Consequently, an archetypal platform is envisaged to study quantum mechanical phenomena due to emergent magnetic charges.

The Effect of Hypoxia on the Expression of CXC Chemokines and CXC Chemokine Receptors-A Review of Literature

Hypoxia is an integral component of the tumor microenvironment. Either as chronic or cycling hypoxia, it exerts a similar effect on cancer processes by activating hypoxia-inducible factor-1 (HIF-1) and nuclear factor (NF-κB), with cycling hypoxia showing a stronger proinflammatory influence. One of the systems affected by hypoxia is the CXC chemokine system. This paper reviews all available information on hypoxia-induced changes in the expression of all CXC chemokines (CXCL1, CXCL2, CXCL3, CXCL4, CXCL5, CXCL6, CXCL7, CXCL8 (IL-8), CXCL9, CXCL10, CXCL11, CXCL12 (SDF-1), CXCL13, CXCL14, CXCL15, CXCL16, CXCL17) as well as CXC chemokine receptors—CXCR1, CXCR2, CXCR3, CXCR4, CXCR5, CXCR6, CXCR7 and CXCR8. First, we present basic information on the effect of these chemoattractant cytokines on cancer processes. We then discuss the effect of hypoxia-induced changes on CXC chemokine expression on the angiogenesis, lymphangiogenesis and recruitment of various cells to the tumor niche, including myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), tumor-associated neutrophils (TANs), regulatory T cells (T_regs) and tumor-infiltrating lymphocytes (TILs). Finally, the review summarizes data on the use of drugs targeting the CXC chemokine system in cancer therapies.

Boosting Nanomedicine Efficacy with Hyperbaric Oxygen Therapy

Nanomedicine has been a hot topic in the field of tumor therapy in the past few decades. Because of the enhanced permeability and retention effect (EPR effect), nanomedicine can passively yet selectively accumulate at tumor tissues. As a result, it can improve drug concentration in tumor tissues and reduce drug distribution in normal tissues, thereby contributing to enhanced antitumor effect and reduced adverse effects. However, the therapeutic efficacy of anticancer nanomedicine is not satisfactory in clinical settings. Therefore, how to improve the clinical therapeutic effect of nanomedicine has become an urgent problem. The grand challenges of nanomedicine lie in how to overcome various pathophysiological barriers and simultaneously kill cancer cells effectively in hypoxic tumor microenvironment (TME). To this end, the development of novel stimuli-responsive nanomedicine has become a new research hotspot. While a great deal of progress has been made in this direction and preclinical results report many different kinds of promising multifunctional smart nanomedicine, the design of these intelligent nanomedicines is often too complicated, the requirements for the preparation processes are strict, the cost is high, and the clinical translation is difficult. Thus, it is more practical to find solutions to promote the therapeutic efficacy of commercialized nanomedicines, for example, Doxil^®, Oncaspar^®, DaunoXome^®, Abraxane^®, to name a few. Increasing attention has been paid to the combination of modern advanced medical technology and nanomedicine for the treatment of various malignancies. Recently, we found that hyperbaric oxygen (HBO) therapy could enhance Doxil^® antitumor efficacy. Inspired by this study, we further carried out researches on the combination of HBO therapy with other nanomedicines for various cancer therapies, and revealed that HBO therapy could significantly boost antitumor efficacy of nanomedicine-mediated photodynamic therapy and photothermal therapy in different kinds of tumors, including hepatocellular carcinoma, breast cancer, and gliomas. Our results implicate that HBO therapy might be a universal strategy to boost therapeutic efficacy of nanomedicine against hypoxic solid malignancies.

Construction and research on size and phase 'fixed-point remodelling' intelligent drug delivery system

It is important to enhance penetration depth of nanomedicine and realise rapid drug release simultaneously at targeted tumour for improving anti-tumour efficiency of chemotherapeutic drugs. This project employed sodium alginate (Alg) as matrix material, to establish tumour-responsive nanogels with particle size conversion and drug controlled release functions. Specifically, tumour-targeting peptide CRGDK was conjugated with Alg first (CRGDK-Alg). Then, doxorubicin (DOX) was efficiently encapsulated in CRGDK-FeAlg nanogel during the cross-linking process (CRGDK-FeAlg/DOX). This system was closed during circulation. Once reaching tumour, the particle size of nanogels was reduced to ∼25 nm, which facilitated deep penetration of DOX in tumour tissues. After entering tumour cells, the size of nanogels was further reduced to ∼10 nm and DOX was released simultaneously. Meanwhile, FeAlg efficiently catalysed H₂O₂ to produce •OH by Fenton reaction, achieving local chemodynamic therapy without O₂ mediation. Results showed CRGDK-FeAlg/DOX significantly inhibited tumour proliferation in vivo with V/V0 of 1.13 after treatment, significantly lower than that of control group with V/V0 of 4.79.

Hypoxia Alters the Expression of CC Chemokines and CC Chemokine Receptors in a Tumor-A Literature Review

Hypoxia, i.e., oxygen deficiency condition, is one of the most important factors promoting the growth of tumors. Since its effect on the chemokine system is crucial in understanding the changes in the recruitment of cells to a tumor niche, in this review we have gathered all the available data about the impact of hypoxia on β chemokines. In the introduction, we present the chronic (continuous, non-interrupted) and cycling (intermittent, transient) hypoxia together with the mechanisms of activation of hypoxia inducible factors (HIF-1 and HIF-2) and NF-κB. Then we describe the effect of hypoxia on the expression of chemokines with the CC motif: CCL1, CCL2, CCL3, CCL4, CCL5, CCL7, CCL8, CCL11, CCL13, CCL15, CCL16, CCL17, CCL18, CCL19, CCL20, CCL21, CCL22, CCL24, CCL25, CCL26, CCL27, CCL28 together with CC chemokine receptors: CCR1, CCR2, CCR3, CCR4, CCR5, CCR6, CCR7, CCR8, CCR9, and CCR10. To better understand the effect of hypoxia on neoplastic processes and changes in the expression of the described proteins, we summarize the available data in a table which shows the effect of individual chemokines on angiogenesis, lymphangiogenesis, and recruitment of eosinophils, myeloid-derived suppressor cells (MDSC), regulatory T cells (T_reg), and tumor-associated macrophages (TAM) to a tumor niche.

Yolk-shell nanovesicles endow glutathione-responsive concurrent drug release and T1 MRI activation for cancer theranostics

The effort of incorporating therapeutic drugs with imaging agents has been one of the mainstreams of nanomedicine, which holds great promise in cancer treatment in terms of monitoring therapeutic drug activity and evaluating prognostic index. However, it is still technically challenging to develop nanomedicine endowing a spatiotemporally controllable mechanism of drug release and activatable imaging capability. Here, we developed a yolk-shell type of GSH-responsive nanovesicles (NVs) in which therapeutic drug (Doxorubicin, DOX) and magnetic resonance imaging (MRI) contrast agent (ultrasmall paramagnetic iron oxide nanoparticles, USPIO NPs) formed complexes (denoted as USD) and were encapsulated inside the NVs. The formation of USD complexes is mediated by both the electrostatic adsorption between DOX and poly(acrylic acid) (PAA) polymers and the DOX-iron coordination effect on USPIO NPs. The obtained USD NVs showed a unique yolk-shell structure with restrained drug activity and quenched T1 MRI contrast ability which, on the other hand, can respond to glutathione (GSH) and lead to drug release and T1 contrast activation in a spatiotemporally concurrent manner. Furthermore, the USD NVs exhibited great potential to kill HCT116 cancer cells in vitro and effectively inhibit the tumor growth in vivo. This study may shed light on the design of sophisticated nanotheranostics in precision nanomedicine.

Fluorinated-functionalized hyaluronic acid nanoparticles for enhanced photodynamic therapy of ocular choroidal melanoma by ameliorating hypoxia

Photodynamic therapy (PDT) is a method for killing cancer cells by employing reactive singlet oxygen (¹O₂). However, the inherent hypoxia and oxygen consumption in tumors during PDT lead to a deficient oxygen supply, which in turn hinder the photodynamic efficacy. To overcome this issue, fluorinated-functionalized polysaccharide-based nanocomplexes were prepared by anchoring perfluorocarbons (PFCs) and pyropheophorbide a (Ppa) onto the polymer chains of hyaluronic acid (HA) to deliver O₂ in hypoxia area. These amphiphilic conjugates can self-assemble into micelles and its application in PDT is evaluated. Due to the high oxygen affinity of perfluorocarbon segments, and the tumor-targeting nature of HA, the photodynamic effect of the oxygen self-carrying micelles is remarkably enhanced, which is confirmed by increased generation of ¹O₂ and elevated phototoxicity in vitro and in vivo. These results emphasize the promising potential of polysaccharide-based nanocomplexes for enhanced PDT of Ocular Choroidal Melanoma.

Smart Nanotherapeutic Targeting of Tumor Vasculature

The past decades have witnessed the development of a field dedicated to targeting tumor vasculature for cancer therapy. In contrast to conventional chemotherapeutics that need to penetrate into tumor tissues for killing tumor cells, the agents targeting tumor vascular system have two major advantages: direct contact with vascular endothelial cells or the blood and less possibility to induce drug resistance because of high gene stability of endothelial cells. More specifically, various angiogenesis inhibitors (AIs) and vascular disrupting agents (VDAs) that block tumor blood supply to inhibit tumor progression, some of which have been applied clinically, have been described. However, off-target effects and high effective doses limit the utility of these formulations in cancer patients. Thus, new strategies with improved therapeutic efficacy and safety are needed for tumor vessel targeting therapy. With the burgeoning developments in nanotechnology, smart nanotherapeutics now offer unprecedented potential for targeting tumor vasculature. Based on specific structural and functional features of the tumor vasculature, a number of different nanoscale delivery systems have been proposed for cancer therapy. In this Account, we summarize several distinct strategies to modulate tumor vasculature with various smart nanotherapeutics for safe and effective tumor therapy developed by our research programs. Inspired by the blood coagulation cascade, we generated nanoparticle-mediated tumor vessel infarction strategies that selectively block tumor blood supply to starve the tumor to death. By specifically delivering thrombin loaded DNA nanorobots (Nanorobot-Th) into tumor vessels, an intratumoral thrombosis is triggered to induce vascular infarction and, ultimately, tumor necrosis. Mimicking the coagulation cascade, a smart polymeric nanogel achieves permanent and peripheral embolization of liver tumors. Considering the critical role of platelets in maintaining tumor vessel integrity, a hybrid (PLP-D-R) nanoparticle selectively depleting tumor-associated platelets (TAP) to boost tumor vessel permeability was developed for enhancing intratumoral drug accumulation. In addition, benefiting from a better understanding of the molecular and cellular underpinnings of vascular normalization, several tumor acidity responsive nanotherapeutics, encapsulating therapeutic peptides, and small interfering RNA were developed to correct the abnormal features of the tumor vasculature. This made the tumor vessels more efficient for drug delivery. While we are still exploring the mechanisms of action of these novel nanoformulations, we expect that the strategies summarized here will offer a promising platform to design effective next-generation nanotherapeutics against cancer and facilitate the clinical translation of smart nanotherapeutics that target tumor vasculature.

Mild thermotherapy and hyperbaric oxygen enhance sensitivity of TMZ/PSi nanoparticles via decreasing the stemness in glioma

Background

Glioma is a common brain tumor with a high mortality rate. A small population of cells expressing stem-like cell markers in glioma contributes to drug resistance and tumor recurrence.

Methods

Porous silicon nanoparticles (PSi NPs) as photothermal therapy (PTT) agents loaded with TMZ (TMZ/PSi NPs), was combined with hyperbaric oxygen (HBO) therapy in vitro and in vivo. To further investigate underlying mechanism, we detected the expression of stem-like cell markers and hypoxia related molecules in vitro and in vivo after treatment of TMZ/PSi NPs in combination with PTT and HBO.

Results

NCH-421K and C6 cells were more sensitive to the combination treatment. Moreover, the expression of stem-like cell markers and hypoxia related molecules were decreased after combination treatment. The in vivo results were in line with in vitro. The combination treatment presents significant antitumor effects in mice bearing C6 tumor compared with the treatment of TMZ, PTT or TMZ/PSi NPs only.

Conclusion

These results suggested the TMZ/PSi NPs combined with HBO and PTT could be a potential therapeutic strategy for glioma.

Electronic supplementary material

The online version of this article (10.1186/s12951-019-0483-1) contains supplementary material, which is available to authorized users.