Tumor Stiffening, a Key Determinant of Tumor Progression, is Reversed by Nanomaterial-Induced Photothermal Therapy

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.

Augmentation of the EPR effect by mild hyperthermia to improve nanoparticle delivery to the tumor

The clinical translation of the nanoparticle (NP)-based anticancer therapies is still unsatisfactory due to the heterogeneity of the enhanced permeability and retention (EPR) effect. Despite the promising preclinical outcome of the pharmacological EPR enhancers, their systemic toxicity can limit their clinical application. Hyperthermia (HT) presents an efficient tool to augment the EPR by improving tumor blood flow (TBF) and vascular permeability, lowering interstitial fluid pressure (IFP), and disrupting the structure of the extracellular matrix (ECM). Furthermore, the HT-triggered intravascular release approach can overcome the EPR effect. In contrast to pharmacological approaches, HT is safe and can be focused to cancer tissues. Moreover, HT conveys direct anti-cancer effects, which improve the efficacy of the anti-cancer agents encapsulated in NPs. However, the clinical application of HT is challenging due to the heterogeneous distribution of temperature within the tumor, the length of the treatment and the complexity of monitoring.

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.

Hyperthermia/glutathione-triggered ferritin nanoparticles amplify the ferroptosis for synergistic tumor therapy

Breast cancer is the most diagnosed malignancy in women globally, and drug resistance is among the major obstacles to effective breast cancer treatment. Emerging evidence indicates that photothermal therapy and ferroptosis are both promising therapeutic techniques for the treatment of drug-resistant breast tumors. In this study, we proposed a thermal/ferroptosis/magnetic resonance imaging (MRI) triple functional nanoparticle (I@P-ss-FRT) in which ferritin, an iron storage material with excellent cellular uptake capacity, was attached via disulfide bonds onto polydopamine coated iron oxide nanoparticle (I@P) as photothermal transduction agent and MRI probe. I@P-ss-FRT converted the near-infrared light (NIR) into localized heat which accelerated the release of ferrous ions from ferritin accomplished by glutathione reduction and subsequently induced ferroptosis. The drug-resistant cancer cell lines exhibited a more significant uptake of I@P-ss-FRT and sensitivity to PTT/ferroptosis compared with normal cancer cell lines. In vivo, I@P-ss-FRT plus NIR displayed the best tumor-killing potential with inhibitory rate of 83.46 %, along with a decline in GSH/GPX-4 content and an increase in lipid peroxides generation at tumor sites. Therefore, I@P-ss-FRT can be applied to combat drug-resistant breast cancer.

Breaking-Down Tumoral Physical Barrier by Remotely Unwrapping Metal-Polyphenol-Packaged Hyaluronidase for Optimizing Photothermal/Photodynamic Therapy-Induced Immune Response

The therapy of solid tumors is often hindered by the compact and rigid tumoral extracellular matrix (TECM). Precise reduction of TECM by hyaluronidase (HAase) in combination with nanotechnology is promising for solid tumor therapeutics, yet remains an enormous challenge. Inspired by the treatment of iron poisoning, here a remotely unwrapping strategy is proposed of metal-polyphenol-packaged HAase (named PPFH) by sequentially injecting PPFH and a clinically used iron-chelator deferoxamine (DFO). The in situ dynamic disassembly of PPFH can be triggered by the intravenously injected DFO, resulting in the release, reactivation, and deep penetration of encapsulated HAase inside tumors. Such a cost-effective HAase delivery strategy memorably improves the subsequent photothermal and photodynamic therapy (PTT/PDT)-induced intratumoral infiltration of cytotoxic T lymphocyte cells and the cross-talk between tumor and tumor-draining lymph nodes (TDLN), thereby decreasing the immunosuppression and optimizing tumoricidal immune response that can efficiently protect mice from tumor growth, metastasis, and recurrence in multiple mouse cancer models. Overall, this work presents a proof-of-concept of the dynamic disassembly of metal-polyphenol nanoparticles for extracellular drug delivery as well as the modulation of TECM and immunosuppressive tumor microenvironment.

Nanomedicine Remodels Tumor Microenvironment for Solid Tumor Immunotherapy

Although immunotherapy is relatively effective in treating hematological malignancies, their efficacy against solid tumors is still suboptimal or even noneffective presently. Compared to hematological cancers, solid tumors exhibit strikingly different immunosuppressive microenvironment, severely deteriorating the efficacy of immunotherapy: (1) chemical features such as hypoxia and mild acidity suppress the activity of immune cells, (2) the pro-tumorigenic domestication of immune cells in the microenvironment within the solid tumors further undermines the effectiveness of immunotherapy, and (3) the dense physical barrier of solid tumor tissues prevents the effective intratumoral infiltration and contact killing of active immune cells. Therefore, we believe that reversing the immunosuppressive microenvironment are of critical priority for the immunotherapy against solid tumors. Due to their unique morphologies, structures, and compositions, nanomedicines have become powerful tools for achieving this goal. In this Perspective, we will first briefly introduce the immunosuppressive microenvironment of solid tumors and then summarize the most recent progresses in nanomedicine-based immunotherapy for solid tumors by remodeling tumor immune-microenvironment in a comprehensive manner. It is highly expected that this Perspective will aid in advancing immunotherapy against solid tumors, and we are highly optimistic on the future development in this burgeoning field.

Monitoring of optical properties of tumors during laser plasmon photothermal therapy

We studied grafted tumors obtained by subcutaneous implantation of kidney cancer cells into male white rats. Gold nanorods with a plasmon resonance of about 800 nm were injected intratumorally for photothermal heating. Experimental irradiation of tumors was carried out percutaneously using a near-infrared diode laser. Changes in the optical properties of the studied tissues in the spectral range 350-2200 nm under plasmonic photothermal therapy (PPT) were studied. Analysis of the observed changes in the absorption bands of water and hemoglobin made it possible to estimate the depth of thermal damage to the tumor. A significant decrease in absorption peaks was observed in the spectrum of the upper peripheral part and especially the tumor capsule. The obtained changes in the optical properties of tissues under laser irradiation can be used to optimize laboratory and clinical PPT procedures.

[Research Progress on the Influence of Tumor Extracellular Matrix Mechanic Properties on Nanodrug Delivery]

Nanodrugs are widely utilized in the biomedical fields, exhibiting immense potential in cancer therapy in particular. However, tumors exist in an extremely complicated microenvironment where substances like collagen are continuously deposited and remodeled, leading to significant alterations in the mechanical properties of the extracellular matrix (ECM) during tumor development. Previous research has primarily focused on the specific physicochemical properties of nanodrugs, such as particle size, electric charge, shape, surface chemistry, etc., and their effects on cellular uptake, cytotoxicity, and in vivo pharmacokinetics. Limited studies have been done to explore the impact of ECM mechanical properties on nanodrug delivery. In this review, we systematically summarized the relevant research findings on this topic from the perspective of the characteristics and testing methods of tumor ECM mechanics. Additionally, we made a thorough discussion of the potential mechanical and biological mechanisms involved in nanodrug delivery. We proposed several noteworthy research directions. Regarding the overall strategy, there is a need to emphasize targeted delivery that combines ECM mechanics and nanomechanics to achieve precise drug delivery. Regarding the spatial aspect, attention should be given to the nonlinear spatial mechanical heterogeneity within the interior of solid tumors and the construction of mechanic microenvironment-adaptive nanocarriers to improve the delivery efficiency. Regarding the temporal aspect, emphasis should be placed on the dynamic development and changes in the mechanical microenvironment during solid tumor growth and treatment processes. Based on the stromal mechanical characteristics of the tumor tissues of individual patients, personalized treatment strategies can be formulated, which will enhance treatment specificity and efficacy. In addition, issues such as mechanically targeted nanodrug delivery, degradation, and metabolism under dynamic ECM mechanical conditions warrant further investigation.

An Integrative Bioorthogonal Nanoengineering Strategy for Dynamically Constructing Heterogenous Tumor Spheroids

Although tumor models have revolutionized perspectives on cancer aetiology and treatment, current cell culture methods remain challenges in constructing organotypic tumor with in vivo-like complexity, especially native characteristics, leading to unpredictable results for in vivo responses. Herein, the bioorthogonal nanoengineering strategy (BONE) for building photothermal dynamic tumor spheroids is developed. In this process, biosynthetic machinery incorporated bioorthogonal azide reporters into cell surface glycoconjugates, followed by reacting with multivalent click ligand (ClickRod) that is composed of hyaluronic acid-functionalized gold nanorod carrying dibenzocyclooctyne moieties, resulting in rapid construction of tumor spheroids. BONE can effectively assemble different cancer cells and immune cells together to construct heterogenous tumor spheroids is identified. Particularly, ClickRod exhibited favorable photothermal activity, which precisely promoted cell activity and shaped physiological microenvironment, leading to formation of dynamic features of original tumor, such as heterogeneous cell population and pluripotency, different maturation levels, and physiological gradients. Importantly, BONE not only offered a promising platform for investigating tumorigenesis and therapeutic response, but also improved establishment of subcutaneous xenograft model under mild photo-stimulation, thereby significantly advancing cancer research. Therefore, the first bioorthogonal nanoengineering strategy for developing dynamic tumor models, which have the potential for bridging gaps between in vitro and in vivo research is presented.

Recent advances on hyperthermia therapy applications of carbon-based nanocomposites

Generally, hyperthermia is referred to the composites capability to increase local temperature in such a way that the generated heat would lead to cancerous or bacteria cells destruction, with minimum damage to normal tissue cells. Many different materials have been utilized for hyperthermia application via different heat generating methods. Carbon-based nanomaterials consisting of graphene oxide (GO), carbon nanotube (CNT), carbon dot (CD) and carbon quantum dot (CQD), nanodiamond (ND), fullerene and carbon fiber (CF), have been studied significantly for different applications including hyperthermia due to their biocompatibility, biodegradability, chemical and physical stability, thermal and electrical conductivity and in some cases photothermal conversion. Therefore, in this comprehensive review, a structure-based view on carbon nanomaterials application in hyperthermia therapy of cancer and bacteria via various methods such as optical, magnetic, ultrasonic and radiofrequency-induced hyperthermia is presented.

Photodynamic and Photothermal Therapies: Synergy Opportunities for Nanomedicine

Tumoricidal photodynamic (PDT) and photothermal (PTT) therapies harness light to eliminate cancer cells with spatiotemporal precision by either generating reactive oxygen species or increasing temperature. Great strides have been made in understanding biological effects of PDT and PTT at the cellular, vascular and tumor microenvironmental levels, as well as translating both modalities in the clinic. Emerging evidence suggests that PDT and PTT may synergize due to their different mechanisms of action, and their nonoverlapping toxicity profiles make such combination potentially efficacious. Moreover, PDT/PTT combinations have gained momentum in recent years due to the development of multimodal nanoplatforms that simultaneously incorporate photodynamically- and photothermally active agents. In this review, we discuss how combining PDT and PTT can address the limitations of each modality alone and enhance treatment safety and efficacy. We provide an overview of recent literature featuring dual PDT/PTT nanoparticles and analyze the strengths and limitations of various nanoparticle design strategies. We also detail how treatment sequence and dose may affect cellular states, tumor pathophysiology and drug delivery, ultimately shaping the treatment response. Lastly, we analyze common experimental design pitfalls that complicate preclinical assessment of PDT/PTT combinations and propose rational guidelines to elucidate the mechanisms underlying PDT/PTT interactions.

Nattokinase-Mediated Regulation of Tumor Physical Microenvironment to Enhance Chemotherapy, Radiotherapy, and CAR-T Therapy of Solid Tumor

The therapy of solid tumors is always hampered by the intrinsic tumor physical microenvironment (TPME) featured with compact and rigid extracellular matrix (ECM) microstructures. Herein, we introduce nattokinase (NKase), a thrombolytic healthcare drug, to comprehensively regulate the TPME for versatile enhancement of various therapy modalities. Intratumoral injection of NKase not only degrades the major ECM component fibronectin but also inhibits cancer-associated fibroblasts (CAFs) in generating fibrosis, resulting in decreased tumor stiffness, enhanced perfusion, and hypoxia alleviation. The NKase-mediated regulation of the TPME significantly promotes the tumoral accumulation of therapeutic agents, leading to efficient chemotherapy without inducing side effects. Additionally, the enhancement of tumor radiotherapy based on radiosensitizers was also achieved by the pretreatment of intratumorally injected NKase, which could be ascribed to the elevated oxygen saturation level in NKase-treated tumors. Moreover, a xenografted human breast MDB-MA-231 tumor model is established to evaluate the influence of NKase on chimeric antigen receptor (CAR)-T cell therapy, illustrating that the pretreatment of NKase could boost the infiltration of CAR-T cells into tumors and thus be a benefit for tumor inhibition. These findings demonstrate the great promise of the NKase-regulated TPME as a translational strategy for universal enhancement of therapeutic efficacy in solid tumors by various treatments.

A Polymeric Extracellular Matrix Nanoremodeler for Activatable Cancer Photo-Immunotherapy

Cancer immunotherapy has shown tremendous potential to train the intrinsic immune system against malignancy in the clinic. However, the extracellular matrix (ECM) in tumor microenvironment is a formidable barrier that not only restricts the penetration of therapeutic drugs but also prevents the infiltration of antitumor immune cells. We herein report a semiconducting polymer-based ECM nanoremodeler (SPNcb) to combine photodynamic antitumor activity with cancer-specific inhibition of collagen-crosslinking enzymes (lysyl oxidase (LOX) family) for activatable cancer photo-immunotherapy. SPNcb is self-assembled from an amphiphilic semiconducting polymer conjugated with a LOX inhibitor (β-aminopropionitrile, BAPN) via a cancer biomarker (cathepsin B, CatB)-cleavable segment. BAPN can be exclusively activated to inhibit LOX activity in the presence of the tumor-overexpressed CatB, thus blocking collagen crosslinking and decreasing ECM stiffness. Such an ECM nanoremodeler synergizes immunogenic phototherapy and checkpoint blockade immunotherapy to improve the tumor infiltration of cytotoxic T cells, inhibiting tumor growth and metastasis.

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.

Gold nanoparticle delivery to solid tumors: a multiparametric study on particle size and the tumor microenvironment

Nanoparticle (NP) delivery to solid tumors remains an actively studied field, where several recent studies have shed new insights into the underlying mechanisms and the still overall poor efficacy. In the present study, Au NPs of different sizes were used as model systems to address this topic, where delivery of the systemically administered NPs to the tumor as a whole or to tumor cells specifically was examined in view of a broad range of tumor-associated parameters. Using non-invasive imaging combined with histology, immunohistochemistry, single-cell spatial RNA expression and image-based single cell cytometry revealed a size-dependent complex interaction of multiple parameters that promoted tumor and tumor-cell specific NP delivery. Interestingly, the data show that most NPs are sequestered by tumor-associated macrophages and cancer-associated fibroblasts, while only few NPs reach the actual tumor cells. While perfusion is important, leaky blood vessels were found not to promote NP delivery, but rather that delivery efficacy correlated with the maturity level of tumor-associated blood vessels. In line with recent studies, we found that the presence of specialized endothelial cells, expressing high levels of CD276 and Plvap promoted both tumor delivery and tumor cell-specific delivery of NPs. This study identifies several parameters that can be used to determine the suitability of NP delivery to the tumor region or to tumor cells specifically, and enables personalized approaches for maximal delivery of nanoformulations to the targeted tumor.

Advances in Tumor Organoids for the Evaluation of Drugs: A Bibliographic Review

Tumor organoids are defined as self-organized three-dimensional assemblies of heterogeneous cell types derived from patient samples that mimic the key histopathological, genetic, and phenotypic characteristics of the original tumor. This technology is proposed as an ideal candidate for the evaluation of possible therapies against cancer, presenting advantages over other models which are currently used. However, there are no reports in the literature that relate the techniques and material development of tumor organoids or that emphasize in the physicochemical and biological properties of materials that intent to biomimicry the tumor extracellular matrix. There is also little information regarding the tools to identify the correspondence of native tumors and tumoral organoids (tumoroids). Moreover, this paper relates the advantages of organoids compared to other models for drug evaluation. A growing interest in tumoral organoids has arisen from 2009 to the present, aimed at standardizing the process of obtaining organoids, which more accurately resemble patient-derived tumor tissue. Likewise, it was found that the characteristics to consider for the development of organoids, and therapeutic responses of them, are cell morphology, physiology, the interaction between cells, the composition of the cellular matrix, and the genetic, phenotypic, and epigenetic characteristics. Currently, organoids have been used for the evaluation of drugs for brain, lung, and colon tumors, among others. In the future, tumor organoids will become closer to being considered a better model for studying cancer in clinical practice, as they can accurately mimic the characteristics of tumors, in turn ensuring that the therapeutic response aligns with the clinical response of patients.

Substrate Type and Concentration Differently Affect Colon Cancer Cells Ultrastructural Morphology, EMT Markers, and Matrix Degrading Enzymes

Aim of the study was to understand the behavior of colon cancer LoVo-R cells (doxorubicin-resistant) vs. LoVo-S (doxorubicin sensitive) in the initial steps of extracellular matrix (ECM) invasion. We investigated how the matrix substrates Matrigel and type I collagen-mimicking the basement membrane (BM) and the normal or desmoplastic lamina propria, respectively-could affect the expression of epithelial-to-mesenchymal transition (EMT) markers, matrix-degrading enzymes, and phenotypes. Gene expression with RT-qPCR, E-cadherin protein expression using Western blot, and phenotypes using scanning electron microscopy (SEM) were analyzed. The type and different concentrations of matrix substrates differently affected colon cancer cells. In LoVo-S cells, the higher concentrated collagen, mimicking the desmoplastic lamina propria, strongly induced EMT, as also confirmed by the expression of Snail, metalloproteases (MMPs)-2, -9, -14 and heparanase (HPSE), as well as mesenchymal phenotypes. Stimulation in E-cadherin expression in LoVo-S groups suggests that these cells develop a hybrid EMT phenotype. Differently, LoVo-R cells did not increase their aggressiveness: no changes in EMT markers, matrix effectors, and phenotypes were evident. The low influence of ECM components in LoVo-R cells might be related to their intrinsic aggressiveness related to chemoresistance. These results improve understanding of the critical role of tumor microenvironment in colon cancer cell invasion, driving the development of new therapeutic approaches.

Hyperthermia-induced stellate cell deactivation to enhance dual chemo and pH-responsive photothermal therapy for pancreatic cancers

For pancreatic ductal adenocarcinoma (PDAC) treatment, the deactivation of pancreatic stellate cells (PSCs) by blocking the transforming growth factor β (TGF-β) pathway is a promising strategy to inhibit stroma, enhance drug penetration, and greatly amplify chemotherapeutic efficacy. It is known that photothermal therapy (PTT) locally depletes stroma and enhances permeability but whether and how PTT reacts in the molecular pathway to induce PSC deactivation in PDAC has rarely been investigated so far. Herein, C-G NPs are synthesized by loading both acid-responsive photothermal molecules and gemcitabine for investigating both the combinatory chemophotothermal therapy and the interaction between the PTT and TGF-β pathway in PDAC. Notably, C-G NPs exhibit tumoral acidic pH-activated PTT and succeeded in deactivating PSCs and suppressing the expression level for both TGF-β and collagen fiber. Furthermore, hyperthermia remodels the tumoral extracellular matrix, significantly improves NP penetration, and boosts the ultimate synergistic chemophotothermal therapeutic efficacy. Importantly, the molecular biology study reveals that hyperthermia leads to the decrease in the mRNA expression of TGF-β1, SMAD2, SMAD3, α-SMA, and Collagen I in the tumor tissue, which is the key to suppress tumor progression. This research demonstrates that combinatory chemophotothermal therapy holds great promise for PDAC treatment.

Biology of cancer; from cellular and molecular mechanisms to developmental processes and adaptation

Cancer research has been largely focused on the cellular and molecular levels of investigation. Recent data show that not only the cell but also the extracellular matrix plays a major role in the progression of malignancy. In this way, the cells and the extracellular matrix create a specific local microenvironment that supports malignant development. At the same time, cancer implies a systemic evolution which is closely related to developmental processes and adaptation. Consequently, there is currently a real gap between the local investigation of cancer at the microenvironmental level, and the pathophysiological approach to cancer as a systemic disease. In fact, the cells and the matrix are not only complementary structures but also interdependent components that act synergistically. Such relationships lead to cell-matrix integration, a supracellular form of biological organization that supports tissue development. The emergence of this supracellular level of organization, as a structure, leads to the emergence of the supracellular control of proliferation, as a supracellular function. In humans, proliferation is generally involved in developmental processes and adaptation. These processes suppose a specific configuration at the systemic level, which generates high-order guidance for local supracellular control of proliferation. In conclusion, the supracellular control of proliferation act as an interface between the downstream level of cell division and differentiation, and upstream level of developmental processes and adaptation. Understanding these processes and their disorders is useful not only to complete the big picture of malignancy as a systemic disease, but also to open new treatment perspectives in the form of etiopathogenic (supracellular or informational) therapies.

Tissue Rigidity Increased during Carcinogenesis of NTCU-Induced Lung Squamous Cell Carcinoma In Vivo

Increased tissue rigidity is an emerging hallmark of cancer as it plays a critical role in promoting cancer growth. However, the field lacks a defined characterization of tissue rigidity in dual-stage carcinogenesis of lung squamous cell carcinoma (SCC) in vivo. Pre-malignant and malignant lung SCC was developed in BALB/c mice using N-nitroso-tris-chloroethylurea (NTCU). Picro sirius red staining and atomic force microscopy were performed to measure collagen content and collagen (diameter and rigidity), respectively. Then, the expression of tenascin C (TNC) protein was determined using immunohistochemistry staining. Briefly, all tissue rigidity parameters were found to be increased in the Cancer group as compared with the Vehicle group. Importantly, collagen content (33.63 ± 2.39%) and TNC expression (7.97 ± 2.04%) were found to be significantly higher (p < 0.05) in the Malignant Cancer group, as compared with the collagen content (18.08 ± 1.75%) and TNC expression (0.45 ± 0.53%) in the Pre-malignant Cancer group, indicating increased tissue rigidity during carcinogenesis of lung SCC. Overall, tissue rigidity of lung SCC was suggested to be increased during carcinogenesis as indicated by the overexpression of collagen and TNC protein, which may warrant further research as novel therapeutic targets to treat lung SCC effectively.

Extracellular Matrix Stiffness in Lung Health and Disease

The extracellular matrix (ECM) provides structural support and imparts a wide variety of environmental cues to cells. In the past decade, a growing body of work revealed that the mechanical properties of the ECM, commonly known as matrix stiffness, regulate the fundamental cellular processes of the lung. There is growing appreciation that mechanical interplays between cells and associated ECM are essential to maintain lung homeostasis. Dysregulation of ECM-derived mechanical signaling via altered mechanosensing and mechanotransduction pathways is associated with many common lung diseases. Matrix stiffening is a hallmark of lung fibrosis. The stiffened ECM is not merely a sequelae of lung fibrosis but can actively drive the progression of fibrotic lung disease. In this article, we provide a comprehensive view on the role of matrix stiffness in lung health and disease. We begin by summarizing the effects of matrix stiffness on the function and behavior of various lung cell types and on regulation of biomolecule activity and key physiological processes, including host immune response and cellular metabolism. We discuss the potential mechanisms by which cells probe matrix stiffness and convert mechanical signals to regulate gene expression. We highlight the factors that govern matrix stiffness and outline the role of matrix stiffness in lung development and the pathogenesis of pulmonary fibrosis, pulmonary hypertension, asthma, chronic obstructive pulmonary disease (COPD), and lung cancer. We envision targeting of deleterious matrix mechanical cues for treatment of fibrotic lung disease. Advances in technologies for matrix stiffness measurements and design of stiffness-tunable matrix substrates are also explored. © 2022 American Physiological Society. Compr Physiol 12:3523-3558, 2022.

Locoregional therapies and their effects on the tumoral microenvironment of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is expected to become the second leading cause of death from cancer by 2030. Despite intensive research in the field of therapeutics, the 5-year overall survival is approximately 8%, with only 20% of patients eligible for surgery at the time of diagnosis. The tumoral microenvironment (TME) of the PDAC is one of the main causes for resistance to antitumoral treatments due to the presence of tumor vasculature, stroma, and a modified immune response. The TME of PDAC is characterized by high stiffness due to fibrosis, with hypo microvascular perfusion, along with an immunosuppressive environment that constitutes a barrier to effective antitumoral treatment. While systemic therapies often produce severe side effects that can alter patients' quality of life, locoregional therapies have gained attention since their action is localized to the pancreas and can thus alleviate some of the barriers to effective antitumoral treatment due to their physical effects. Local hyperthermia using radiofrequency ablation and radiation therapy - most commonly using a local high single dose - are the two main modalities holding promise for clinical efficacy. Recently, irreversible electroporation and focused ultrasound-derived cavitation have gained increasing attention. To date, most of the data are limited to preclinical studies, but ongoing clinical trials may help better define the role of these locoregional therapies in the management of PDAC patients.

Targeting extracellular matrix stiffness and mechanotransducers to improve cancer therapy

Cancer microenvironment is critical for tumorigenesis and cancer progression. The extracellular matrix (ECM) interacts with tumor and stromal cells to promote cancer cells proliferation, migration, invasion, angiogenesis and immune evasion. Both ECM itself and ECM stiffening-induced mechanical stimuli may activate cell membrane receptors and mechanosensors such as integrin, Piezo1 and TRPV4, thereby modulating the malignant phenotype of tumor and stromal cells. A better understanding of how ECM stiffness regulates tumor progression will contribute to the development of new therapeutics. The rapidly expanding evidence in this research area suggests that the regulators and effectors of ECM stiffness represent potential therapeutic targets for cancer. This review summarizes recent work on the regulation of ECM stiffness in cancer, the effects of ECM stiffness on tumor progression, cancer immunity and drug resistance. We also discuss the potential targets that may be druggable to intervene ECM stiffness and tumor progression. Based on these advances, future efforts can be made to develop more effective and safe drugs to interrupt ECM stiffness-induced oncogenic signaling, cancer progression and drug resistance.

Exploiting ECM remodelling to promote immune-mediated tumour destruction

Cancer immunotherapy represents a significant breakthrough in cancer treatment mainly due to the ability to harness the activities of cancer-specific T cells. Despite this, most cancers remain resistant to T cell attack. Many reasons have been proposed to explain this, ranging from a lack of antigenicity through to the immunosuppressive effects of the tumour microenvironment. In this review, we examine the relationship between the immune system and a key component of the tumour microenvironment, namely the extracellular matrix (ECM). Specifically, we explore the reciprocal effects of immune cells and the tumour ECM and how the processes underpinning this relationship act to either promote or restrain tumour progression.

Insights on functionalized carbon nanotubes for cancer theranostics

Despite the exciting breakthroughs in medical technology, cancer still accounts for one of the principle triggers of death and conventional therapeutic modalities often fail to attain an effective cure. Recently, nanobiotechnology has made huge advancement in cancer therapy with gigantic application potential because of their ability in achieving precise and controlled drug release, elevating drug solubility and reducing adverse effects. Carbon nanotubes (CNTs), one of the most promising carbon-related nanomaterials, have already achieved much success in biomedical field. Due to their excellent optical property, thermal and electronic conductivity, easy functionalization ability and high drug loading capacity, CNTs can be applied in a multifunctional way for cancer treatment and diagnosis. In this review, we will give an overview of the recent progress of CNT-based drug delivery systems in cancer theranostics, which emphasizes their targetability to intracellular components of tumor cells and extracellular elements in tumor microenvironment. Moreover, a detailed introduction on how CNTs penetrate inside the tumor cells to reach their sites of action and achieve the therapeutic effects, as well as their diagnostic applications will be highlighted.

A DiR loaded tumor targeting theranostic cisplatin-icodextrin prodrug nanoparticle for imaging guided chemo-photothermal cancer therapy

Imaging-guided diagnosis and chemo-photothermal combination therapy have promising applications for the treatment of cancer. Nevertheless, the accurate diagnosis and efficient treatment of tumors are not yet satisfactory. Herein, a tumor targeting DiR loaded cisplatin-icodextrin prodrug nanoparticle, with selective drug release, was fabricated as a multifunctional theranostic nanoplatform for chemo-photothermal combination therapy. By loading DiR into the hydrophobic domain of folic acid-icodextrin-polycaprolactone (FA-ICO-PCL, FIP) and cisplatin-icodextrin-polycaprolactone (Pt-ICO-PCL, PtIP) co-assembly, the resultant DiR@(PtIP + FIP) (DPtFIP) NPs had a diameter of around 70 nm and showed excellent tumor targeting ability and negligible side effects. Moreover, the DPtFIP NPs achieved real-time NIR fluorescence imaging of solid tumors with high contrast. By the accurate tumor imaging, local laser irradiation dramatically enhanced the chemotherapy for triple-negative breast cancer. Such a biocompatible nanotherapeutic holds great potential for tumor diagnosis and imaging-guided combinational cancer therapy.

The Role of Ultrasound in Modulating Interstitial Fluid Pressure in Solid Tumors for Improved Drug Delivery

The unique microenvironment of solid tumors, including desmoplasia within the extracellular matrix, enhanced vascular permeability, and poor lymphatic drainage, leads to an elevated interstitial fluid pressure which is a major barrier to drug delivery. Reducing tumor interstitial fluid pressure is one proposed method of increasing drug delivery to the tumor. The goal of this topical review is to describe recent work using focused ultrasound with or without microbubbles to modulate tumor interstitial fluid pressure, through either thermal or mechanical effects on the extracellular matrix and the vasculature. Furthermore, we provide a review on techniques in which ultrasound imaging may be used to diagnose elevated interstitial fluid pressure within solid tumors. Ultrasound-based techniques show high promise in diagnosing and treating elevated interstitial pressure to enhance drug delivery.

Recent advances in regenerative medicine strategies for cancer treatment

Cancer stands as one of the most leading causes of death worldwide, while one of the most significant challenges in treating it is revealing novel alternatives to predict, diagnose, and eradicate tumor cell growth. Although various methods, such as surgery, chemotherapy, and radiation therapy, are used today to treat cancer, its mortality rate is still high due to the numerous shortcomings of each approach. Regenerative medicine field, including tissue engineering, cell therapy, gene therapy, participate in cancer treatment and development of cancer models to improve the understanding of cancer biology. The final intention is to convey fundamental and laboratory research to effective clinical treatments, from the bench to the bedside. Proper interpretation of research attempts helps to lessen the burden of treatment and illness for patients. The purpose of this review is to investigate the role of regenerative medicine in accelerating and improving cancer treatment. This study examines the capabilities of regenerative medicine in providing novel cancer treatments and the effectiveness of these treatments to clarify this path as much as possible and promote advanced future research in this field.

Tumor stiffening reversion through collagen crosslinking inhibition improves T cell migration and anti-PD-1 treatment

Only a fraction of cancer patients benefits from immune checkpoint inhibitors. This may be partly due to the dense extracellular matrix (ECM) that forms a barrier for T cells. Comparing five preclinical mouse tumor models with heterogeneous tumor microenvironments, we aimed to relate the rate of tumor stiffening with the remodeling of ECM architecture and to determine how these features affect intratumoral T cell migration. An ECM-targeted strategy, based on the inhibition of lysyl oxidase, was used. In vivo stiffness measurements were found to be strongly correlated with tumor growth and ECM crosslinking but negatively correlated with T cell migration. Interfering with collagen stabilization reduces ECM content and tumor stiffness leading to improved T cell migration and increased efficacy of anti-PD-1 blockade. This study highlights the rationale of mechanical characterizations in solid tumors to understand resistance to immunotherapy and of combining treatment strategies targeting the ECM with anti-PD-1 therapy.

Nanomedicine-based strategies to target and modulate the tumor microenvironment

The interest in nanomedicine for cancer theranostics has grown significantly over the past few decades. However, these nanomedicines need to overcome several physiological barriers intrinsic to the tumor microenvironment (TME) before reaching their target. Intrinsic tumor genetic/phenotypic variations, along with intratumor heterogeneity, provide different cues to each cancer type, making each patient with cancer unique. This brings additional challenges in translating nanotechnology-based systems into clinically reliable therapies. To develop efficient therapeutic strategies, it is important to understand the dynamic interactions between TME players and the complex mechanisms involved, because they constitute invaluable targets to dismantle tumor progression. In this review, we discuss the latest nanotechnology-based strategies for cancer diagnosis and therapy as well as the potential targets for the design of future anticancer nanomedicines.

Biomechanical sensing of in vivo magnetic nanoparticle hyperthermia-treated melanoma using magnetomotive optical coherence elastography

Rationale: Magnetic nanoparticle hyperthermia (MH) therapy is capable of thermally damaging tumor cells, yet a biomechanically-sensitive monitoring method for the applied thermal dosage has not been established. Biomechanical changes to tissue are known indicators for tumor diagnosis due to its association with the structural organization and composition of tissues at the cellular and molecular level. Here, by exploiting the theranostic functionality of magnetic nanoparticles (MNPs), we aim to explore the potential of using stiffness-based metrics that reveal the intrinsic biophysical changes of in vivo melanoma tumors after MH therapy. Methods: A total of 14 melanoma-bearing mice were intratumorally injected with dextran-coated MNPs, enabling MH treatment upon the application of an alternating magnetic field (AMF) at 64.7 kHz. The presence of the MNP heating sources was detected by magnetomotive optical coherence tomography (MM-OCT). For the first time, the elasticity alterations of the hyperthermia-treated, MNP-laden, in vivo tumors were also measured with magnetomotive optical coherence elastography (MM-OCE), based on the mechanical resonant frequency detected. To investigate the correlation between stiffness changes and the intrinsic biological changes, histopathology was performed on the excised tumor after the in vivo measurements. Results: Distinct shifts in mechanical resonant frequency were observed only in the MH-treated group, suggesting a heat-induced stiffness change in the melanoma tumor. Moreover, tumor cellularity, protein conformation, and temperature rise all play a role in tumor stiffness changes after MH treatment. With low cellularity, tumor softens after MH even with low temperature elevation. In contrast, with high cellularity, tumor softening occurs only with a low temperature rise, which is potentially due to protein unfolding, whereas tumor stiffening was seen with a higher temperature rise, likely due to protein denaturation. Conclusions: This study exploits the theranostic functionality of MNPs and investigates the MH-induced stiffness change on in vivo melanoma-bearing mice with MM-OCT and MM-OCE for the first time. It was discovered that the elasticity alteration of the melanoma tumor after MH treatment depends on both thermal dosage and the morphological features of the tumor. In summary, changes in tissue-level elasticity can potentially be a physically and physiologically meaningful metric and integrative therapeutic marker for MH treatment, while MM-OCE can be a suitable dosimetry technique.

Stiffness increases with myofibroblast content and collagen density in mesenchymal high grade serous ovarian cancer

Women diagnosed with high-grade serous ovarian cancers (HGSOC) are still likely to exhibit a bad prognosis, particularly when suffering from HGSOC of the Mesenchymal molecular subtype (50% cases). These tumors show a desmoplastic reaction with accumulation of extracellular matrix proteins and high content of cancer-associated fibroblasts. Using patient-derived xenograft mouse models of Mesenchymal and Non-Mesenchymal HGSOC, we show here that HGSOC exhibit distinct stiffness depending on their molecular subtype. Indeed, tumor stiffness strongly correlates with tumor growth in Mesenchymal HGSOC, while Non-Mesenchymal tumors remain soft. Moreover, we observe that tumor stiffening is associated with high stromal content, collagen network remodeling, and MAPK/MEK pathway activation. Furthermore, tumor stiffness accompanies a glycolytic metabolic switch in the epithelial compartment, as expected based on Warburg's effect, but also in stromal cells. This effect is restricted to the central part of stiff Mesenchymal tumors. Indeed, stiff Mesenchymal tumors remain softer at the periphery than at the core, with stromal cells secreting high levels of collagens and showing an OXPHOS metabolism. Thus, our study suggests that tumor stiffness could be at the crossroad of three major processes, i.e. matrix remodeling, MEK activation and stromal metabolic switch that might explain at least in part Mesenchymal HGSOC aggressiveness.

Exploiting Unique Alignment of Cobalt Ferrite Nanoparticles, Mild Hyperthermia, and Controlled Intrinsic Cobalt Toxicity for Cancer Therapy

Nanoparticle-based magnetic hyperthermia is a well-known thermal therapy platform studied to treat solid tumors, but its use for monotherapy is limited due to incomplete tumor eradication at hyperthermia temperature (45 °C). It is often combined with chemotherapy for obtaining a more effective therapeutic outcome. Cubic-shaped cobalt ferrite nanoparticles (Co-Fe NCs) serve as magnetic hyperthermia agents and as a cytotoxic agent due to the known cobalt ion toxicity, allowing the achievement of both heat and cytotoxic effects from a single platform. In addition to this advantage, Co-Fe NCs have the unique ability to form growing chains under an alternating magnetic field (AMF). This unique chain formation, along with the mild hyperthermia and intrinsic cobalt toxicity, leads to complete tumor regression and improved overall survival in an in vivo murine xenograft model, all under clinically approved AMF conditions. Numerical calculations identify magnetic anisotropy as the main Co-Fe NCs' feature to generate such chain formations. This novel combination therapy can improve the effects of magnetic hyperthermia, inaugurating investigation of mechanical behaviors of nanoparticles under AMF, as a new avenue for cancer therapy.

The Roles of Tissue Rigidity and Its Underlying Mechanisms in Promoting Tumor Growth

Tissues become more rigid during tumorigenesis and have been identified as a driving factor for tumor growth. Here, we highlight the concept of tissue rigidity, contributing factors that increase tissue rigidity, and mechanisms that promote tumor growth initiated by increased tissue rigidity. Various factors lead to increased tissue rigidity, promoting tumor growth by activating focal adhesion kinase (FAK) and Rho-associated kinase (ROCK). Consequently, result in recruitment of cancer-associated fibroblasts (CAFs), epithelial-mesenchymal transition (EMT) and tumor protection from immunosurveillance. We also discussed the rationale for targeting tumor tissue rigidity and its potential for cancer treatment.

The Treatment of Heterotopic Human Colon Xenograft Tumors in Mice with 5-Fluorouracil Attached to Magnetic Nanoparticles in Combination with Magnetic Hyperthermia Is More Efficient than Either Therapy Alone

Magnetic nanoparticles (MNPs) have shown promising features to be utilized in combinatorial magnetic hyperthermia and chemotherapy. Here, we assessed if a thermo-chemotherapeutic approach consisting of the intratumoral application of functionalized chitosan-coated MNPs (CS-MNPs) with 5-fluorouracil (5FU) and magnetic hyperthermia prospectively improves the treatment of colorectal cancer. With utilization of a human colorectal cancer (HT29) heterotopic tumor model in mice, we showed that the thermo-chemotherapeutic treatment is more efficient in inactivating colon cancer than either tumor treatments alone (i.e., magnetic hyperthermia vs. the presence of 5FU attached to MNPs). In particular, the thermo-chemotherapeutic treatment significantly (p < 0.01) impacts tumor volume and tumor cell proliferation (Ki67 expression, p < 0.001) compared to the single therapy modalities. The thermo-chemotherapeutic treatment: (a) affects DNA replication and repair as measured by H2AX and phosphorylated H2AX expression (p < 0.05 to 0.001), (b) it does not distinctly induce apoptosis nor necroptosis in target cells, since expression of p53, PARP cleaved-PARP, caspases and phosphorylated-RIP3 was non-conspicuous, (c) it renders tumor cells surviving therapy more sensitive to further therapy sessions as indicated by an increased expression of p53, reduced expression of NF-κB and HSPs, albeit by tendency with p > 0.05), and (d) that it impacts tumor vascularity (reduced expression of CD31 and αvβ3 integrin (p < 0.01 to 0.001) and consequently nutrient supply to tumors. We further hypothesize that tumor cells die, at least in parts, via a ROS dependent mechanism called oxeiptosis. Taken together, a very effective elimination of colon cancers seems to be feasible by utilization of repeated thermo-chemotherapeutic therapy sessions in the long-term.

Vascular and extracellular matrix remodeling by physical approaches to improve drug delivery at the tumor site

INTRODUCTION

Modern comprehensive studies of tumor microenvironment changes allowed scientists to develop new and more efficient strategies that will improve anticancer drug delivery on site. The tumor microenvironment, especially the dense extracellular matrix, has a recognized capability to hamper the penetration of conventional drugs. Development and co-applications of strategies aiming at remodeling the tumor microenvironment are highly demanded to improve drug delivery at the tumor site in a therapeutic prospect.

AREAS COVERED

Increasing indications suggest that classical physical approaches such as exposure to ionizing radiations, hyperthermia or light irradiation, and emerging ones as sonoporation, electric field or cold plasma technology can be applied as standalone or associated strategies to remodel the tumor microenvironment. The impacts on vasculature and extracellular matrix remodeling of these physical approaches will be discussed with the goal to improve nanotherapeutics delivery at the tumor site.

EXPERT OPINION

Physical approaches to modulate vascular properties and remodel the extracellular matrix are of particular interest to locally control and improve drug delivery and thus increase its therapeutic index. They are particularly powerful as adjuvant to nanomedicine delivery; the development of these technologies could have extremely widespread implications for cancer treatment.[Figure: see text].

Hyperthermia affects collagen fiber architecture and induces apoptosis in pancreatic and fibroblast tumor hetero-spheroids in vitro

Desmoplasia, an aberrant production of extracellular matrix (ECM), is considered as one predictive marker of malignancy of pancreatic cancer. In this paper, we study the effect of mild hyperthermia on fibrillary collagen architecture in murine Achilles tendons and in a pancreatic cancer model, in vitro, i.e. 3D hetero-type tumor spheroids, consisting of pancreatic cancer (Panc-1) cells and fibroblasts (WI-38), producing collagen fibers. We clearly demonstrate that i) mild hyperthermia (40 °C, 42 °C) damages the collagen architecture in murine Achilles tendons. ii) Mild extrinsic (hot air) and iron oxide nanoparticle based magnetic hyperthermia reduce the level of collagen fiber architecture in the generated hetero-type tumor spheroids. iii) Mild magnetic hyperthermia reduces cell vitality mainly through apoptotic and necrotic processes in the generated tumor spheroids. In conclusion, hetero-type 3D tumor spheroids are suitable for studying the effect of hyperthermia on collagen fibers, in vitro.

Histological validation of in vivo assessment of cancer tissue inhomogeneity and automated morphological segmentation enabled by Optical Coherence Elastography

We present a non-invasive (albeit contact) method based on Optical Coherence Elastography (OCE) enabling the in vivo segmentation of morphological tissue constituents, in particular, monitoring of morphological alterations during both tumor development and its response to therapies. The method uses compressional OCE to reconstruct tissue stiffness map as the first step. Then the OCE-image is divided into regions, for which the Young’s modulus (stiffness) falls in specific ranges corresponding to the morphological constituents to be discriminated. These stiffness ranges (characteristic "stiffness spectra") are initially determined by careful comparison of the "gold-standard" histological data and the OCE-based stiffness map for the corresponding tissue regions. After such pre-calibration, the results of morphological segmentation of OCE-images demonstrate a striking similarity with the histological results in terms of percentage of the segmented zones. To validate the sensitivity of the OCE-method and demonstrate its high correlation with conventional histological segmentation we present results obtained in vivo on a murine model of breast cancer in comparative experimental study of the efficacy of two antitumor chemotherapeutic drugs with different mechanisms of action. The new technique allowed in vivo monitoring and quantitative segmentation of (1) viable, (2) dystrophic, (3) necrotic tumor cells and (4) edema zones very similar to morphological segmentation of histological images. Numerous applications in other experimental/clinical areas requiring rapid, nearly real-time, quantitative assessment of tissue structure can be foreseen.

Photothermal Depletion of Cancer-Associated Fibroblasts Normalizes Tumor Stiffness in Desmoplastic Cholangiocarcinoma

Physical oncology recognizes tissue stiffness mediated by activation of cancer-associated fibroblasts (CAF) and extracellular matrix remodeling as an active modulator of tumorigenesis, treatment resistance, and clinical outcome. Cholangiocarcinoma (CCA) is a highly aggressive and chemoresistant desmoplastic cancer enriched in CAF. CCA's stroma mechanical properties are considered responsible for its chemoresistant character. To normalize tumor mechanics, we propose a physical strategy based on remotely light-activated nanohyperthermia to modulate the tumor microenvironment. In this study, we report the use of multifunctional iron oxide nanoflowers decorated with gold nanoparticles (GIONF) as efficient nanoheaters to achieve complete tumor regression following three sessions of mild hyperthermia. The preferential uptake of GIONF by CAF allowed targeting this cell population, which resulted in a significant early reduction of tumor stiffness followed by tumor regression. In conclusion, our study highlights a spatially and temporally controlled physical strategy, GIONF-mediated photothermal therapy to deplete CAF and normalize the tumor mechanics that may apply to desmoplastic cancer and CCA treatment.

Effects of ‎Bioactive ‎Marine-Derived ‎Liposomes on ‎Two ‎Human ‎Breast Cancer ‎‎Cell Lines

Breast cancer is the leading cause of death from cancer among women. Higher consumption of dietary marine n-3 long-chain polyunsaturated fatty acids (LC-PUFAs) is associated with a lower risk of breast cancer. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are two n-3 LC-PUFAs found in fish and exert anticancer effects. In this study, natural marine-derived lecithin that is rich in various polyunsaturated fatty acids (PUFAs) was extracted from salmon heads and transformed into nanoliposomes. These nanoliposomes were characterized and cultured with two breast cancer lines (MCF-7 and MDA-MB-231). The nanoliposomes decreased the proliferation and the stiffness of both cancer cell types. These results suggest that marine-derived lecithin possesses anticancer properties, which may have an impact on developing new liposomal delivery strategies for breast cancer treatment.

Gallbladder Cancer Progression Is Reversed by Nanomaterial-Induced Photothermal Therapy in Combination with Chemotherapy and Autophagy Inhibition

Introduction

Gallbladder cancer (GBC) is the most common malignancy in biliary tract with extremely poor prognosis. Photothermal therapy (PTT) shows great promises for tumor therapy, which causes tumor cell death via selectively directed heating released by nanoparticles under the near-infrared irradiation. Through degrading damaged organelles and misfolded proteins in autophagosomes, autophagy plays a vital role in maintaining the intracellular homeostasis. The present study attempted to combine chemotherapy and autophagy blocking with PTT.

Materials and Methods

We purchased multi-walled carbon nanotubes from Nanostructured and Amorphous Materials and performed PTT using an 808-nm diode laser. The cytotoxic effects of PTT and chemotherapy in vitro were assessed by cell viability analysis. The effects of PTT and chemotherapy on autophagy in vitro were assessed by GFP-LC3 and Western blot. And these results were confirmed by in vivo experiment.

Results

Both PTT and chemotherapy could trigger cytoprotective autophagy to tolerate the cellular stresses and prolong the survival of GBC cell; therefore, the blocking of autophagy could enhance the efficacy of PTT and chemotherapy in GBC treatment in vitro and in vivo.

Conclusion

Chemotherapeutic drug doxorubicin and autophagy inhibitor chloroquine could enhance the efficacy of nanoparticle-mediated hyperthermia in GBC.

Immune-mediated ECM depletion improves tumour perfusion and payload delivery

High extracellular matrix (ECM) content in solid cancers impairs tumour perfusion and thus access of imaging and therapeutic agents. We have devised a new approach to degrade tumour ECM, which improves uptake of circulating compounds. We target the immune‐modulating cytokine, tumour necrosis factor alpha (TNFα), to tumours using a newly discovered peptide ligand referred to as CSG. This peptide binds to laminin–nidogen complexes in the ECM of mouse and human carcinomas with little or no peptide detected in normal tissues, and it selectively delivers a recombinant TNFα‐CSG fusion protein to tumour ECM in tumour‐bearing mice. Intravenously injected TNFα‐CSG triggered robust immune cell infiltration in mouse tumours, particularly in the ECM‐rich zones. The immune cell influx was accompanied by extensive ECM degradation, reduction in tumour stiffness, dilation of tumour blood vessels, improved perfusion and greater intratumoral uptake of the contrast agents gadoteridol and iron oxide nanoparticles. Suppressed tumour growth and prolonged survival of tumour‐bearing mice were observed. These effects were attainable without the usually severe toxic side effects of TNFα.

Experimental pancreatic cancer develops in soft pancreas: novel leads for an individualized diagnosis by ultrafast elasticity imaging

Rapid, easy and early pancreatic cancer diagnosis and therapeutic follow up continue to necessitate an increasing attention towards the development of effective treatment strategies for this lethal disease. The non invasive quantitative assessment of pancreatic heterogeneity is limited. Here, we report the development of a preclinical imaging protocol using ultrasonography and shear wave technology in an experimental in situ pancreatic cancer model to measure the evolution of pancreatic rigidity.

Methods: Intrapancreatic tumors were genetically induced by mutated Kras and p53 in KPC mice. We evaluated the feasiblity of a live imaging protocol by assessing pancreas evolution with Aixplorer technology accross 36 weeks. Lethality induced by in situ pancreatic cancer was heterogeneous in time.

Results: The developed method successfully detected tumor mass from 26 weeks onwards at minimal 0.029 cm³ size. Elastography measurements using shear wave methodology had a wide detection range from 4.7kPa to 166.1kPa. Protumorigenic mutations induced a significant decrease of the rigidity of pancreatic tissue before tumors developed in correlation with the detection of senescent marker p16-positive cells. An intratumoral increased rigidity was quantified and found surprisingly heterogeneous. Tumors also presented a huge inter-individual heterogeneity in their rigidity parameters; tumors with low and high rigidity at detection evolve very heterogeneously in their rigidity parameters, as well as in their volume. Increase in rigidity in tumors detected by ultrafast elasticity imaging coincided with detection of tumors by echography and with the detection of the inflammatory protumoral systemic condition by non invasive follow-up and of collagen fibers by post-processing tumoral IHC analysis.

Conclusion: Our promising results indicate the potential of the shear wave elastography to support individualization of diagnosis in this most aggressive disease.

Theoretical and experimental modeling of interstitial laser hyperthermia with surface cooling device using Nd3+-doped nanoparticles

To improve methods of laser hyperthermia for the treatment of bulk malignant neoplasms, an urgent task is the development of techniques and devices that automatically control heating at a given tissue depth and ensure its uniformity. The article proposes the concept of a system for performing hyperthermia with real-time spectroscopic temperature control and surface cooling, which allows to record spectra of diffusely scattered radiation and fluorescent signal from various depths of biological tissues by the means of the variation of the angle and distance between the fiber source of laser radiation and the receiving fiber. Theoretical and experimental modeling of the spatial distribution of diffusely scattered radiation and temperature inside the tissue with a fiber optic device providing surface cooling of the irradiated tissue, and recording spectral information from a given depth in real time, is presented. Simulation of radiation propagation in biological tissues, depending on the distance between the source and the receiver and the angle of their tilt, was carried out using the Monte Carlo method. Modeling of the temperature distribution inside the tissues was carried out by means of a numerical solution of the heat conduction equation. Experimental modeling was carried out on phantoms of biological tissues simulating their scattering properties as well as accumulation of the investigated nanoparticles doped with Nd³⁺ ions. It was shown that inorganic nanoparticles doped with rare-earth Nd³⁺ ions can be used as temperature labels for feedback to the therapeutic laser. According to the results of the theoretical simulation, optimal configurations of the relative arrangement of the fibers were chosen, as well as the optimum surface cooling temperatures for the given power densities. The heating of the phantom of the neoplasm containing the investigated nanoparticles doped with Nd³⁺ ions by laser radiation with an 805-nm wavelength and power density of 1 W/cm² up to 42 °C at a depth of 1 cm while maintaining the surface temperature within the limits of the norm was demonstrated.

Obstacles to T cell migration in the tumor microenvironment

These last years, significant progress has been made in the design of strategies empowering T cells with efficient anti-tumor activities. Hence, adoptive T cell therapy and the use of monoclonal antibodies against the immunosuppressive surface molecules CTLA-4 and PD-1 appear as the most promising immunotherapies against cancer. One of the challenges ahead is to render these therapeutic interventions even more effective as a still elevated fraction of cancer patients is refractory to these treatments. A frequently overlooked determinant of the success of T cell-based immunotherapy relates to the ability of effector T cells to migrate into and within tumors, as well as to have access to tumor antigens. Here, we will focus on recent advances in understanding T cell trafficking into and within tumors. Both chemoattractant molecules and structural determinants are essential for regulating T cell motile behavior along with cellular interactions-mediated antigen recognition. In addition, we will review evidence that the microenvironment of advanced tumors creates multiple obstacles limiting T cells from migrating and making contact with their malignant targets. We will particularly focus on the extracellular matrix and tumor-associated macrophages that make tumors a hostile environment for T cell ability to contact and kill malignant cells. Finally, we will discuss possible strategies to restore a tumor microenvironment more favorable to T cell migration and functions with a special emphasis on approaches targeting the dysregulated extracellular matrix of growing tumors.

Biomaterials to model and measure epithelial cancers

The use of biomaterials has substantially contributed to both our understanding of tumorigenesis and our ability to identify and capture tumour cells in vitro and in vivo. Natural and synthetic biomaterials can be applied as models to recapitulate key features of the tumour microenvironment in vitro, including architectural, mechanical and biological functions. Engineered biomaterials can further mimic the spatial and temporal properties of the surrounding tumour niche to investigate the specific effects of the environment on disease progression, offering an alternative to animal models for the testing of cancer cell behaviour. Biomaterials can also be used to capture and detect cancer cells in vitro and in vivo to monitor tumour progression. In this Review, we discuss the natural and synthetic biomaterials that can be used to recreate specific features of tumour microenvironments. We examine how biomaterials can be applied to capture circulating tumour cells in blood samples for the early detection of metastasis. We highlight biomaterial-based strategies to investigate local regions adjacent to the tumour and survey potential applications of biomaterial-based devices for diagnosis and prognosis, such as the detection of cellular deformability and the non-invasive surveillance of tumour-adjacent stroma.

Silk fibroin nanoparticles dyeing indocyanine green for imaging-guided photo-thermal therapy of glioblastoma

Silk was easily dyed in traditional textile industry because of its strong affinity to many colorants. Herein, the biocompatible silk fibroin was firstly extracted from Bombyx mori silkworm cocoons. And SF nanoparticles (SFNPs) were prepared for dyeing indocyanine green (ICG) and construct a therapeutic nano-platform (ICG-SFNPs) for photo-thermal therapy of glioblastoma. ICG was easily encapsulated into SFNPs with a very high encapsulation efficiency reaching to 97.7 ± 1.1%. ICG-SFNPs exhibited a spherical morphology with a mean particle size of 209.4 ± 1.4 nm and a negative zeta potential of −31.9 mV, exhibiting a good stability in physiological medium. Moreover, ICG-SFNPs showed a slow release profile of ICG in vitro, and only 24.51 ± 2.27% of the encapsulated ICG was released even at 72 h. Meanwhile, ICG-SFNPs exhibited a more stable photo-thermal effect than free ICG after exposure to near-infrared irradiation. The temperature of ICG-SFNPs rapidly increased by 33.9 °C within 10 min and maintained for a longer time. ICG-SFNPs were also easily internalized with C₆ tumor cells in vitro, and a strong red fluorescence of ICG was observed in cytoplasm for cellular imaging. In vivo imaging showed that ICG-SFNPs were effectively accumulated inside tumor site of C₆ glioma-bearing Xenograft nude mice through vein injection. Moreover, the temperature of tumor site was rapidly rising up to kill tumor cells after local NIR irradiation. After treatment, its growth was completely suppressed with the relative tumor volume of 0.55 ± 033 while free ICG of 33.72 ± 1.90. Overall, ICG-SFNPs may be an effective therapeutic means for intraoperative phototherapy and imaging.