Metformin-Induced Stromal Depletion to Enhance the Penetration of Gemcitabine-Loaded Magnetic Nanoparticles for Pancreatic Cancer Targeted Therapy

Bioactive polymers as stimulus-responsive anti-metastatic combination agents to treat pancreatic cancer

The intractable and devastating nature of pancreatic ductal adenocarcinoma (PDAC) necessitates an urgent need for novel therapies. This study presents the development of a novel polymer prodrug system for the combination treatment of PDAC, based on an optimized pharmacologically active anti-metastatic macromolecular carrier, PCQ, conjugated with gemcitabine (GEM). Structure-activity relationship evaluations showed that random PCQ copolymers exhibited superior anti-migratory activity compared to the gradient PCQ analogs. GEM was incorporated into the random PCQ copolymers using disulfide linker to prepare a reduction-responsive prodrug, PCQ(r)6-SS-GEM12. The resultant therapeutic system presents a pharmacologically active delivery strategy that targets both the proliferative and the metastatic phenotype in PDAC. The PCQ(r)6-SS-GEM12 prodrug demonstrated a selective release of GEM under the reductive tumor environment leading to a significant inhibition of tumor growth with pronounced anti-metastatic effect. Collectively, our data show that the combination of anti-metastatic PCQ and cytotoxic GEM-based reduction-responsive prodrug polymer offers an innovative strategy to treat PDAC.

Organelle-oriented nanomedicines in tumor therapy: Targeting, escaping, or collaborating?

Precise tumor therapy is essential for improving treatment specificity, enhancing efficacy, and minimizing side effects. Targeting organelles is a key strategy for achieving this goal and is a frontier research area attracting a considerable amount of attention. The concept of organelle targeting has a significant effect on the structural design of the nanodrugs employed. Most notably, the intricate interactions among different organelles in a tumor cell essentially create a unified system. Unfortunately, this aspect might have been somewhat overlooked when existing organelle-targeting nanodrugs were designed. In this review, we underscore the synergistic relationship among the various organelles and advocate for a holistic view of organelle-targeting design. Through the integration of biology and material science, recent advancements in organelle targeting, escaping, and collaborating are consolidated to offer fresh perspectives for the development of antitumor nanomedicines.

Magnesium peroxide-based biomimetic nanoigniter degrades extracellular matrix to awake T cell-mediated cancer immunotherapy

As the elite force of our immune system, T cells play a determining role in the effectiveness of cancer immunotherapy. However, the clever tumor cells construct a strong immunosuppressive tumor microenvironment (TME) fortress to resist the attack of T cells. Herein, a magnesium peroxide (MP)-based biomimetic nanoigniter loaded with doxorubicin (DOX) and metformin (MET) is rationally designed (D/M-MP@LM) to awake T cell-mediated cancer immunotherapy via comprehensively destroying the strong TME fortress. The nanoigniter not only effectively initiate CD8+ T cell-mediated immune response by promoting the presentation of tumor antigens, but also greatly facilitate the infiltration of T cells by degrading rigid extracellular matrix (ECM). More importantly, the nanoigniter significantly augment the effector functions of infiltrated CD8+ T cells by Mg2+-mediated metalloimmunotherapy and avoid the exhaustion of CD8+ T cells by improving the acidic TME. Thus, the nanoigniter comprehensively awakes T cells and achieves remarkable tumor inhibition efficacy.

Pancreatic stellate cell: Update on molecular investigations and clinical translation in pancreatic cancer

Pancreatic cancer is a particularly aggressive tumor, distinguished by the presence of a prominent collagenous stroma and desmoplasia that envelops the tumor cells. Pancreatic stellate cell (PSC) contributes to the formation of a dense fibrotic stroma and has been demonstrated to facilitate tumor progression. As the significance of PSCs is increasingly revealed, more explorations are focused on the complex molecular mechanisms and tumor-stromal crosstalk in order to guide potential therapeutic approaches through deactivating or reprogramming PSCs. Nevertheless, significant challenges persist in translating preclinical discoveries into clinical applications. In this review, we expect to offer a comprehensive overview of the latest molecular advancements in PSCs, along with new insights into the clinical therapeutic strategies targeting PSCs.

Nanotension Relief Agent Enhances Tissue Penetration by Reducing Solid Stress in Pancreatic Ductal Adenocarcinoma via Rho/ROCK Pathway Inhibition

The formidable contractile tension exerted by cancer-associated fibroblasts (CAFs) in pancreatic ductal adenocarcinoma (PDAC) tissue is crucial for maintaining high tissue solid stress (TSS), which impedes the delivery and penetration of chemotherapeutic drugs. To address this obstacle, we constructed a pH-responsive nanotension relief agent (FS@MMS), in which fasudil (FS) was ingeniously conjugated to mesoporous silica encapsulated with magnetic iron oxide (MMS). The nanotension relief agent was demonstrated to inhibit the synthesis of phosphorylated myosin light chain by blocking the Rho/Rho-associated serine/threonine kinase (ROCK) pathway, triggering the swift transformation of high-tension CAFs into low-tension CAFs in PDAC tissue, which relieves TSS and enhances drug penetration in Panc02/NIH-3T3 multicellular tumor spheroids. When the nanotension relief agent was further loaded with the chemotherapeutic drug gemcitabine (GEM), as FS@MMS-GEM, the enhanced permeation of GEM progressively killed tumor cells and amplified their TSS-relief properties, thereby maximizing the anticancer efficacy of chemotherapeutic agents in Panc02/NIH-3T3 coplanted model mice. The magnetic resonance imaging results revealed that the synergistic effect substantially improved drug delivery and penetration efficiency. The developed approach holds great potential for improving chemotherapy efficacy in PDAC and provides a novel therapeutic approach for the treatment of related stroma-rich tumors.

Peptide-modified nanoparticles for doxorubicin delivery: Strategies to overcome chemoresistance and perspectives on carbohydrate polymers

Chemotherapy serves as the primary treatment for cancers, facing challenges due to the emergence of drug resistance. Combination therapy has been developed to combat cancer drug resistance, yet it still suffers from lack of specific targeting of cancer cells and poor accumulation at the tumor site. Consequently, targeted administration of chemotherapy medications has been employed in cancer treatment. Doxorubicin (DOX) is one of the most frequently used chemotherapeutics, functioning by inhibiting topoisomerase activity. Enhancing the anti-cancer effects of DOX and overcoming drug resistance can be accomplished via delivery by nanoparticles. This review will focus on the development of peptide-DOX conjugates, the functionalization of nanoparticles with peptides, the co-delivery of DOX and peptides, as well as the theranostic use of peptide-modified nanoparticles in cancer treatment. The peptide-DOX conjugates have been designed to enhance the targeted delivery to cancer cells by interacting with receptors that are overexpressed on tumor surfaces. Moreover, nanoparticles can be modified with peptides to improve their uptake in tumor cells via endocytosis. Nanoparticles have the ability to co-deliver DOX along with therapeutic peptides for enhanced cancer treatment. Finally, nanoparticles modified with peptides can offer theranostic capabilities by facilitating both imaging and the delivery of DOX (chemotherapy).

Dual Cascade-Responsive Multifunctional Nanoparticles to Overcome Bacterium-Induced Drug Inactivation and Enhanced Photodynamic and Chemo-Immunotherapy of Pancreatic Cancer

The harsh biological barriers and bacteria within tumor microenvironment not only hinder drug penetration and induce drug inactivation, but also inhibit antitumor immune responses. Here a tumor microenvironment dual cascade-responsive multifunctional nanoparticle, Gem/Emo@NP@GHA is reported, which is engineered from a hyaluronidase (HAase)-responsive guanidine group functionalized hyaluronic acid (GHA) shell and a glutathione (GSH)-responsive biopolymer core (Gem/Emo@NP), that encapsulates anticancer drug gemcitabine (Gem) and two-photon-excited photosensitizer emodin (Emo). The constructed Gem/Emo@NP@GHA can specifically target the tumor and subsequently be degraded by HAase-abundant in the extracellular matrix. Thus, the resulting Gem/Emo@NP achieved size reduction and charge reversal, strengthening deep tumor penetration. Upon internalization, the positively charged Gem/Emo@NP effectively kills intratumor bacteria by inducing membrane depolarization. Furthermore, the high levels of GSH within tumor cells disrupt the disulfide bonds of Gem/Emo@NP, triggering drug release. Thereby, the undecomposed Gem successfully induces tumor cell apoptosis and necrosis. Under laser irradiation, photosensitizer Emo generates high singlet oxygen (1O2), further eliminating tumors and intracellular bacteria. More importantly, Gem/Emo@NP@GHA can activate T cell-mediated immune response, further enhancing antitumor activity. These findings provide a promising approach to treating bacterially infected tumors through the synergistic application of chem-immunotherapy and two-photon-excited photodynamic therapy.

Manganese nanosheets loaded with selenium and gemcitabine activate the tumor microenvironment to enhance anti-tumor immunity

Breast cancer is among the most common malignant tumors globally. Despite advances in immunotherapy and targeted therapies, chemotherapy remains the primary clinical treatment. Gemcitabine, a cytosine nucleoside analog, is widely used for various solid tumors; however, its effectiveness is often limited by drug resistance and adverse side effects. In this study, we developed a novel drug delivery system, Mn/Se-Gem, designed to target tumor cells overexpressing CD44 and facilitate the controlled release of gemcitabine. This system exploits gemcitabine's pH sensitivity and HA-mediated CD44 targeting to induce DNA damage. Simultaneously, it neutralizes the acidic tumor microenvironment and releases nano-selenium and manganese ions, which promote the excessive production of reactive oxygen species (ROS), leading to mitochondrial damage and enhanced apoptosis of cancer cells. Furthermore, Mn (II) activates the cGAS-STING pathway, increasing susceptibility to ROS-induced DNA double-strand breaks, promoting macrophage maturation, inhibiting M2 polarization, and enhancing the cytotoxic function of T lymphocytes against tumor cells. In summary, this combination of chemotherapy and immunotherapy presents a promising strategy for the treatment of breast cancer.

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

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

Enhancement of Bone Repair in Diabetic Rats with Metformin-Modified Silicified Collagen Scaffolds

Regenerating bone defects in diabetic rats presents a significant challenge due to the detrimental effects of reactive oxygen species and impaired autophagy on bone healing. To address these issues, a metformin-modified biomimetic silicified collagen scaffold is developed utilizing the principles of biomimetic silicification. In vitro and in vivo experiments demonstrated that the scaffold enhanced bone tissue regeneration within the diabetic microenvironment through the release of dual bio-factors. Further analysis reveals a potential therapeutic mechanism whereby these dual bio-factors synergistically promoted osteogenesis in areas of diabetic bone defects by improving mitochondrial autophagy and maintaining redox balance. The present study provides critical insights into the advancement of tissue engineering strategies aimed at bone regeneration in diabetic patients. The study also sheds light on the underlying biological mechanisms.

Functionalized Iron Oxide Nanoparticles for Both Dual-Modal Imaging and Erythropoiesis

Cancer-related anemia (CRA), a complication of cancer, is considered the primary cause of high mortality for cancer patients. Safe and effective theranostics are desirable for realizing the high diagnostic accuracy of tumors and ameliorating CRA in the clinic. However, the available theranostics do not support dual-modal imaging and the amelioration of CRA at the same time. In this study, we synthesized functionalized iron oxide nanoparticles (Fe3O4 NPs) modified with protoporphyrin IX (PPIX) and folic acid (FA) by a one-step modification strategy (Fe3O4@NH-PPIX&FA NPs) or a step-by-step strategy (Fe3O4@NH-PPIX-FA NPs), aiming at both magnetic resonance imaging/fluorescence imaging (MRI/FI) and erythropoiesis. Fe3O4@NH-PPIX-FA NPs displayed better ability of MRI/FI than Fe3O4@NH-PPIX&FA NPs and had an efficient tumor targeting of 45 min after tail vein injection owing to the reduction of the steric effect and extension of FA groups. Fe3O4@NH-PPIX-FA NPs exhibited satisfactory erythropoiesis with up to 20% elevation of red blood cell (RBC) counts and hemoglobin concentrations in mice with CRA, which provided a safe alternative to RBC transfusions, especially for patients needing recurrent RBC transfusions. With excellent performance in both dual-modal imaging and erythropoiesis, Fe3O4@NH-PPIX-FA NPs could be a powerful tool for the theranostics of cancer patients with anemia.

A Modular Approach to Obtain HER2-Targeting DM1-Loaded Nanoparticles for Gastric Cancer Therapy

Antibody-based tumor-targeting nanomedicines, despite their high efficacy, present significant challenges in preparation and long-term storage. We introduce a novel approach for the synthesis of durable, ready-to-use, antibody-coupled nanomedical drugs. Our research centers on the development of HER2-targeting DM1-loaded nanoparticles for gastric cancer treatment using a modular methodology. We synthesized Fc-PLG-Mal, conjugated DM1 through a "click" reaction, and subsequently bound the resultant compound with the HER2 antibody trastuzumab. The nanoparticles demonstrated a high drug loading content, stable particle size, and effective HER2 targeting. HER2-PLG-DM1 exhibited significant cytotoxicity against NCI-N87 gastric cancer cells, with an IC50 of 0.35 nM. Biodistribution revealed rapid and substantial tumor accumulation, 6-fold higher than that of nontargeting IgG-PLG-DM1. HER2-PLG-DM1 significantly inhibited tumor growth in NCI-N87 tumor-bearing mice, achieving a 90.8% tumor inhibition rate, and displayed dose-dependent effects without significant liver and kidney toxicity. These studies offer an efficient and stable method for the preparation of antibody-coupled drugs.

Nanomedicine regulating PSC-mediated intercellular crosstalk: Mechanisms and therapeutic strategies

Pancreatic fibrosis (PF) is primarily distinguished by the stimulation of pancreatic stellate cells (PSCs) and excessive extracellular matrix deposition, which is the main barrier impeding drug delivery and distribution. Recently, nanomedicine, with efficient, targeted, and controllable drug release characteristics, has demonstrated enormous advantages in the regression of pancreas fibrotic diseases. Notably, paracrine signals from parenchymal and immune cells such as pancreatic acinar cells, islet cells, pancreatic cancer cells, and immune cells can directly or indirectly modulate PSC differentiation and activation. The intercellular crosstalk between PSCs and these cells has been a critical event involved in fibrogenesis. However, the connections between PSCs and other pancreatic cells during the progression of diseases have yet to be discussed. Herein, we summarize intercellular crosstalk in the activation of PSCs and its contribution to the development of common pancreatic diseases, including pancreatitis, pancreatic cancer, and diabetes. Then, we also examine the latest treatment strategies of nanomedicine and potential targets for PSCs crosstalk in fibrosis, thereby offering innovative insights for the design of antifibrotic nanomedicine. Ultimately, the enhanced understanding of PF will facilitate the development of more precise intervention strategies and foster individually tailored therapeutic approaches for pancreatic diseases.

Advancements in therapeutic peptides: Shaping the future of cancer treatment

In the evolving landscape of cancer treatment, therapeutic peptides are assuming to play an increasingly vital role. Although the number of peptide drugs available for clinical cancer treatment is currently limited, extensive preclinical research is underway, presenting a promising trajectory for the future. The collaborative efforts of natural anti-cancer peptides (ACPs) and synthetic ACPs, propelled by advancements in molecular biology and peptide chemistry, are steering remarkable progress in this domain. We explores the intricate mechanisms underlying the anti-cancer effects of these peptides. The exploration of innovative strategies, including cancer immunotherapy and advanced drug delivery systems, is likely to contribute to the increasing presenceuse of peptide drugs in clinical cancer care. Furthermore, we delve into the potential implications and challenges associated with this anticipated shift, emphasizing the need for continued research and development to unlock the full therapeutic potential of peptide drugs in cancer treatment.

Jump-starting chimeric antigen receptor-T cells to go the extra mile with nanotechnology

Despite success in treating hematologic malignancies, chimeric antigen receptor-T cell (CAR-T) therapy still faces multiple challenges that have halted progress, especially against solid tumors. Recent advances in nanoscale engineeirng provide several avenues for overcoming these challenges, including more efficienct programming of CAR-Ts ex vivo, promoting immune responsiveness in the tumor microenvironment (TME) in vivo, and boosting CAR-T function in situ. Here, we summarize recent innovations that leverage nanotechnology to directly address the major obstacles that impede CAR-T therapy from reaching its full potential across various cancer types. We conclude with a commentary on the state of the field and how nanotechnology can shape the future of CAR-T and adoptive cell therapy in immuno-oncology.

Dual-Prodrug-Based Hyaluronic Acid Nanoplatform Provides Cascade-Boosted Drug Delivery for Oxidative Stress-Enhanced Chemotherapy

Insufficient drug accumulation in tumors severely limits the antitumor efficiency of hyaluronic acid (HA) nanomedicine in solid tumors due to superficial penetration depth, low cell uptake, and nonspecific drug release. Hence, we constructed a dual NO prodrug (alkynyl-JSK) and doxorubicin prodrug (cis-DOX)-conjugated HA nanoparticle (HA-DOX-JSK NPs), which achieved cascade-boosted drug delivery efficiency based on a relay strategy of NO-mediated deep tumor penetration─HA target CD44 tumor cell uptake─tumor microenvironment (TME)-responsive drug release. The nanoparticle demonstrated sustained and locoregionally GSH/GST-triggered NO release and GSH/pH-responsive DOX release in the tumor. The released NO first mediated collagen degradation, causing deep tumor penetration of nanoparticles in the dense extracellular matrix. Immediately, HA was relayed to enhance CD44-targeted tumor cell uptake, and then, the nanoparticles were finally triggered by specific TME to release DOX and NO in the deep tumor. Relying on the relayed delivery strategy, a significant improvement of DOX accumulation in tumors was realized. Moreover, NO depleted GSH-induced intracellular reactive oxygen species, enhancing DOX chemotherapy. Based on this strategy, the tumor inhibition rate in breast cancer was up to 87.8% in vivo. The relay drug-delivery HA system would greatly cascade-boost drug accumulation in deep tumors for efficient solid tumor therapy.

Development of Dual Diagnostic-Therapeutic Nanoformulation Effective Against Pancreatic Cancer in Animal Model

Purpose

Erythrocytes and fibroblasts in the pancreatic cancer tumor microenvironment promote tumor cell growth and invasion by providing nutrients and promoting immunosuppression. Additionally, they form a barrier against the penetration of chemotherapeutic drugs. Therefore, the search for diversified tumor-targeting materials plays an essential role in solving the above problems.

Methods

Physicochemical characterization of Graphene fluorescent nanoparticles (GFNPs) and nanomedicines were analyzed by transmission electron microscopy (TEM), elemental analyzers and ultraviolet fluorescence (UV/FL) spectrophotometer. Localization of GFNPs in cell and tissue sections imaged with laser confocal microscope, fluorescence scanner and small animal in vivo imager. Qualitative detection and quantitative detection of GFNPs and GFNPs-GEM were performed using High performance liquid chromatography (HPLC).

Results

Based on the 3 nm average dimensions, GFNPs penetrate vascular endothelial cells and smooth muscle cells, achieve up to label 30% tumor cells and 60% cancer-associated fibroblasts (CAFs) cells, and accurately label mature red blood cells in the tumor microenvironment. In orthotopic transplanted pancreatic cancer models, the fluorescence intensity of GFNPs in tumors showed a positive correlation with the cycle size of tumor development. The differential spatial distribution of GFNPs in three typical clinical pancreatic cancer samples demonstrated their diagnostic potential. To mediate the excellent targeting properties of GFNPs, we synthesized a series of nanomedicines using popular chemotherapeutic drugs, in which complex of GFNPs and gemcitabine (GFNPs-GEM) possessed stability in vivo and exhibited effective reduction of tumor volume and fewer side effects.

Conclusion

GFNPs with multiple targeting tumor microenvironments in pancreatic cancer possess diagnostic efficiency and therapeutic potential.

Mitochondrial metabolism blockade nanoadjuvant reversed immune-resistance microenvironment to sensitize albumin-bound paclitaxel-based chemo-immunotherapy

Currently, the efficacy of albumin-bound paclitaxel (PTX@Alb) is still limited due to the impaired PTX@Alb accumulation in tumors partly mediated by the dense collagen distribution. Meanwhile, acquired immune resistance always occurs due to the enhanced programmed cell death-ligand 1 (PD-L1) expression after PTX@Alb treatment, which then leads to immune tolerance. To fill these gaps, we newly revealed that tamoxifen (TAM), a clinically widely used adjuvant therapy for breast cancer with mitochondrial metabolism blockade capacity, could also be used as a novel effective PD-L1 and TGF-β dual-inhibitor via inducing the phosphorylation of adenosine 5'-monophosphate-activated protein kinase (AMPK) protein. Following this, to obtain a more significant effect, TPP-TAM was prepared by conjugating mitochondria-targeted triphenylphosphine (TPP) with TAM, which then further self-assembled with albumin (Alb) to form TPP-TAM@Alb nanoparticles. By doing this, TPP-TAM@Alb nanoparticles effectively decreased the expression of collagen in vitro, which then led to the enhanced accumulation of PTX@Alb in 4T1 tumors. Besides, TPP-TAM@Alb also effectively decreased the expression of PD-L1 and TGF-β in tumors to better sensitize PTX@Alb-mediated chemo-immunotherapy by enhancing T cell infiltration. All in all, we newly put forward a novel mitochondrial metabolism blockade strategy to inhibit PTX@Alb-resistant tumors, further supporting its better clinical application.

Probiotics functionalized with a gallium-polyphenol network modulate the intratumor microbiota and promote anti-tumor immune responses in pancreatic cancer

The intratumor microbiome imbalance in pancreatic cancer promotes a tolerogenic immune response and triggers immunotherapy resistance. Here we show that Lactobacillus rhamnosus GG probiotics, outfitted with a gallium-polyphenol network (LGG@Ga-poly), bolster immunotherapy in pancreatic cancer by modulating microbiota-immune interactions. Upon oral administration, LGG@Ga-poly targets pancreatic tumors specifically, and selectively eradicates tumor-promoting Proteobacteria and microbiota-derived lipopolysaccharides through a gallium-facilitated disruption of bacterial iron respiration. This elimination of intratumor microbiota impedes the activation of tumoral Toll-like receptors, thus reducing immunosuppressive PD-L1 and interleukin-1β expression by tumor cells, diminishing immunotolerant myeloid populations, and improving the infiltration of cytotoxic T lymphocytes in tumors. Moreover, LGG@Ga-poly hampers pancreatic tumor growth in both preventive and therapeutic contexts, and amplifies the antitumor efficacy of immune checkpoint blockade in preclinical cancer models in female mice. Overall, we offer evidence that thoughtfully designed biomaterials targeting intratumor microbiota can efficaciously augment immunotherapy for the challenging pancreatic cancer.

Breaking Down Barriers in Drug Delivery by Stromal Remodeling Approaches in Pancreatic Cancer

Pancreatic cancer remains a formidable challenge in oncology due to its aggressive nature and limited treatment options. The dense stroma surrounding pancreatic tumors not only provides structural support but also presents a formidable barrier to effective therapy, hindering drug penetration and immune cell infiltration. This review delves into the intricate interplay between stromal components and cancer cells, highlighting their impact on treatment resistance and prognosis. Strategies for stromal remodeling, including modulation of cancer-associated fibroblasts (CAFs), pancreatic stellate cells (PSCs) activation states, and targeting extracellular matrix (ECM) components, are examined for their potential to enhance drug penetration and improve therapeutic efficacy. Integration of stromal remodeling with conventional therapies, such as chemotherapy and immunotherapy, is discussed along with the emerging field of intelligent nanosystems for targeted drug delivery. This comprehensive overview underscores the importance of stromal remodeling in pancreatic cancer treatment and offers insights into promising avenues for future research and clinical translation.

Unzippable Siamese Nanoparticles for Programmed Two-Stage Cancer Immunotherapy

Epigenetic drugs (epi-drugs) can destruct cancer cells and initiate both innate and adaptive immunity, yet they have achieved very limited success in solid tumors so far, partly attributing to their concurrent induction of the myeloid-derived suppressor cell (MDSC) population. Here, dissociable Siamese nanoparticles (SIANPs) are developed for tumor cell-targeted delivery of epi-drug CM-272 and MDSC-targeted delivery of small molecule inhibitor Ibrutinib. The SIANPs are assembled via interparticle DNA annealing and detached via tumor microenvironment-triggered strand separation. Such binary regulation induces endogenous retrovirus expression and immunogenic cell death in tumor cells while restraining the immunosuppressive effects of MDSCs, and synergistically promotes dendritic cell maturation and CD8+ T cell activation for tumor inhibition. Significantly, immune microenvironment remodeling via SIANPs further overcomes tumor resistance to immune checkpoint blockade therapy. This study represents a two-pronged approach for orchestrating immune responses, and paves a new way for employing epi-drugs in cancer immunotherapy.

Emerging mechanisms and promising approaches in pancreatic cancer metabolism

Pancreatic cancer is an aggressive cancer with a poor prognosis. Metabolic abnormalities are one of the hallmarks of pancreatic cancer, and pancreatic cancer cells can adapt to biosynthesis, energy intake, and redox needs through metabolic reprogramming to tolerate nutrient deficiency and hypoxic microenvironments. Pancreatic cancer cells can use glucose, amino acids, and lipids as energy to maintain malignant growth. Moreover, they also metabolically interact with cells in the tumour microenvironment to change cell fate, promote tumour progression, and even affect immune responses. Importantly, metabolic changes at the body level deserve more attention. Basic research and clinical trials based on targeted metabolic therapy or in combination with other treatments are in full swing. A more comprehensive and in-depth understanding of the metabolic regulation of pancreatic cancer cells will not only enrich the understanding of the mechanisms of disease progression but also provide inspiration for new diagnostic and therapeutic approaches.

Mitochondria-Targeted Nanoadjuvants Induced Multi-Functional Immune-Microenvironment Remodeling to Sensitize Tumor Radio-Immunotherapy

It is newly revealed that collagen works as a physical barrier to tumor immune infiltration, oxygen perfusion, and immune depressor in solid tumors. Meanwhile, after radiotherapy (RT), the programmed death ligand-1 (PD-L1) overexpression and transforming growth factor-β (TGF-β) excessive secretion would accelerate DNA damage repair and trigger T cell exclusion to limit RT efficacy. However, existing drugs or nanoparticles can hardly address these obstacles of highly effective RT simultaneously, effectively, and easily. In this study, it is revealed that inducing mitochondria dysfunction by using oxidative phosphorylation inhibitors like Lonidamine (LND) can serve as a highly effective multi-immune pathway regulation strategy through PD-L1, collagen, and TGF-β co-depression. Then, IR-LND is prepared by combining the mitochondria-targeted molecule IR-68 with LND, which then is loaded with liposomes (Lip) to create IR-LND@Lip nanoadjuvants. By doing this, IR-LND@Lip more effectively sensitizes RT by generating more DNA damage and transforming cold tumors into hot ones through immune activation by PD-L1, collagen, and TGF-β co-inhibition. In conclusion, the combined treatment of RT and IR-LND@Lip ultimately almost completely suppressed the growth of bladder tumors and breast tumors.

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.

A Cathepsin B-Sensitive Gemcitabine Prodrug for Enhanced Pancreatic Cancer Therapy

Although gemcitabine (GEM) is a first-line chemotherapeutic drug in treating pancreatic cancer, the therapeutic efficacy of GEM is relatively poor. One main reason is that GEM can be easily deaminated to inactive 2',2'-difluorodeoxyuridine (dFdU) by cytidine deaminase (CDA). In order to improve the antitumor activity of GEM, a polypeptide modified GEM prodrug RGDGFLG-GEM (GEM-RGD) is designed. Because the amino group of GEM is protected by RGDGFLG peptide sequence, the in vivo stability of GEM-RGD can be significantly improved since the deamination of GEM can be avoided. GEM-RGD shows enhanced uptake by pancreatic cancer cells due to the active targeting RGD group. The cathepsin B-sensitive GFLG sequence endows GEM-RGD with specific release of GEM in pancreatic cancer cells. Compared to free GEM and non-targeted GEM prodrug RDGGFLG-GEM (GEM-RDG), GEM-RGD exhibits enhanced antitumor activity and reduced systemic toxicity. These results implies that GEM-RGD is a promising candidate in treating pancreatic cancer.

Recent Advances in Nanomedicine for Ocular Fundus Neovascularization Disease Management

As an indispensable part of the human sensory system, visual acuity may be impaired and even develop into irreversible blindness due to various ocular pathologies. Among ocular diseases, fundus neovascularization diseases (FNDs) are prominent etiologies of visual impairment worldwide. Intravitreal injection of anti-vascular endothelial growth factor drugs remains the primary therapy but is hurdled by common complications and incomplete potency. To renovate the current therapeutic modalities, nanomedicine emerged as the times required, which is endowed with advanced capabilities, able to fulfill the effective ocular fundus drug delivery and achieve precise drug release control, thus further improving the therapeutic effect. This review provides a comprehensive summary of advances in nanomedicine for FND management from state-of-the-art studies. First, the current therapeutic modalities for FNDs are thoroughly introduced, focusing on the key challenges of ocular fundus drug delivery. Second, nanocarriers are comprehensively reviewed for ocular posterior drug delivery based on the nanostructures: polymer-based nanocarriers, lipid-based nanocarriers, and inorganic nanoparticles. Thirdly, the characteristics of the fundus microenvironment, their pathological changes during FNDs, and corresponding strategies for constructing smart nanocarriers are elaborated. Furthermore, the challenges and prospects of nanomedicine for FND management are thoroughly discussed.

Chemically Mediated Artificial Electron Transport Chain

Electron transport chains (ETCs) are ubiquitous in nearly all living systems. Replicating the complexity and control inherent in these multicomponent systems using ensembles of small molecules opens up promising avenues for molecular therapeutics, catalyst design, and the development of innovative energy conversion and storage systems. Here, we present a noncovalent, multistep artificial electron transport chains comprising cyclo[8]pyrrole (1), a meso-aryl hexaphyrin(1.0.1.0.1.0) (naphthorosarin 2), and the small molecules I2 and trifluoroacetic acid (TFA). Specifically, we show that 1) electron transfer occurs from 1 to give I3 - upon the addition of I2, 2) proton-coupled electron transfer (PCET) from 1 to give H 3 2 •2+ and H 3 2 + upon the addition of TFA to a dichloromethane mixture of 1 and 2, and 3) that further, stepwise treatment of 1 and 2 with I2 and TFA promotes electron transport from 1 to give first I3 - and then H 3 2 •2+ and H 3 2 + . The present findings are substantiated through UV-vis-NIR, 1H NMR, electron paramagnetic resonance (EPR) spectroscopic analyses, cyclic voltammetry studies, and DFT calculations. Single-crystal structure analyses were used to characterize compounds in varying redox states.

Optimization and mechanisms of proteolytic enzyme immobilization onto large-pore mesoporous silica nanoparticles: Enhanced tumor penetration

Immobilization of proteolytic enzymes onto nanocarriers is effective to improve drug diffusion in tumors through degrading the dense extracellular matrix (ECM). Herein, immobilization and release behaviors of hyaluronidase, bromelain, and collagenase (Coll) on mesoporous silica nanoparticles (MSNs) were explored. A series of cationic MSNs (CMSNs) with large and adjustable pore sizes were synthesized, and investigated together with two anionic MSNs of different pore sizes. CMSNs4.0 exhibited the highest enzyme loading capacity for hyaluronidase and bromelain, and CMSNs4.5 was the best for Coll. High electrostatic interaction, matched pore size, and large pore volume and surface area favor the immobilization. Changes of the enzyme conformations and surface charges with pH, existence of a space around the immobilized enzymes, and the depth of the pore structures, affect the release ratio and tunability. The optimal CMSNs-enzyme complexes exhibited deep and homogeneous penetration into pancreatic tumors, a tumor model with the densest ECM, with CMSNs4.5-Coll as the best. Upon loading with doxorubicin (DOX), the CMSNs-enzyme complexes induced high anti-tumor efficiencies. Conceivably, the DOX/CMSNs4.5-NH2-Coll nanodrug exhibited the most effective tumor therapy, with a tumor growth inhibition ratio of 86.1 %. The study provides excellent nanocarrier-enzyme complexes, and offers instructive theories for enhanced tumor penetration and therapy.

Frontiers and future of immunotherapy for pancreatic cancer: from molecular mechanisms to clinical application

Pancreatic cancer is a highly aggressive malignant tumor, that is becoming increasingly common in recent years. Despite advances in intensive treatment modalities including surgery, radiotherapy, biological therapy, and targeted therapy, the overall survival rate has not significantly improved in patients with pancreatic cancer. This may be attributed to the insidious onset, unknown pathophysiology, and poor prognosis of the disease. It is therefore essential to identify and develop more effective and safer treatments for pancreatic cancer. Tumor immunotherapy is the new and fourth pillar of anti-tumor therapy after surgery, radiotherapy, and chemotherapy. Significant progress has made in the use of immunotherapy for a wide variety of malignant tumors in recent years; a breakthrough has also been made in the treatment of pancreatic cancer. This review describes the advances in immune checkpoint inhibitors, cancer vaccines, adoptive cell therapy, oncolytic virus, and matrix-depletion therapies for the treatment of pancreatic cancer. At the same time, some new potential biomarkers and potential immunotherapy combinations for pancreatic cancer are discussed. The molecular mechanisms of various immunotherapies have also been elucidated, and their clinical applications have been highlighted. The current challenges associated with immunotherapy and proposed strategies that hold promise in overcoming these limitations have also been discussed, with the aim of offering new insights into immunotherapy for pancreatic cancer.

Nanodrug-bacteria conjugates-mediated oncogenic collagen depletion enhances immune checkpoint blockade therapy against pancreatic cancer

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) cancer cells specifically produce abnormal oncogenic collagen to bind with integrin α3β1 receptor and activate the downstream focal adhesion kinase (FAK), protein kinase B (AKT), and mitogen-activated protein kinase (MAPK) signaling pathway. Collectively, this promotes immunosuppression and tumor proliferation and restricts the response rate of clinical cancer immunotherapies.

METHODS

Here, by leveraging the hypoxia tropism and excellent motility of the probiotic Escherichia coli strain Nissle 1917 (ECN), we developed nanodrug-bacteria conjugates to penetrate the extracellular matrix (ECM) and shuttle the surface-conjugated protein cages composed of collagenases and anti-programmed death-ligand 1 (PD-L1) antibodies to PDAC tumor parenchyma.

FINDINGS

We found the oncogenic collagen expression in human pancreatic cancer patients and demonstrated its interaction with integrin α3β1. We proved that reactive oxygen species (ROS) in the microenvironment of PDAC triggered collagenase release to degrade oncogenic collagen and block integrin α3β1-FAK signaling pathway, thus overcoming the immunosuppression and synergizing with anti-PD-L1 immunotherapy.

CONCLUSIONS

Collectively, our study highlights the significance of oncogenic collagen in PDAC immunotherapy, and consequently, we developed a therapeutic strategy that can deplete oncogenic collagen to synergize with immune checkpoint blockade for enhanced PDAC treatment efficacy.

FUNDING

This work was supported by the University of Wisconsin Carbone Cancer Center Research Collaborative and Pancreas Cancer Research Task Force, UWCCC Transdisciplinary Cancer Immunology-Immunotherapy Pilot Project, and the start-up package from the University of Wisconsin-Madison (to Q.H.).

A Hybrid Nanoadjuvant Simultaneously Depresses PD-L1/TGF-β1 and Activates cGAS-STING Pathway to Overcome Radio-Immunotherapy Resistance

Currently, certain cancer patients exhibit resistance to radiotherapy due to reduced DNA damage under hypoxic conditions and acquired immune tolerance triggered by transforming growth factor-β1 (TGF-β1) and membrane-localized programmed death ligand-1 (PD-L1). Meanwhile, cytoplasm-distributed PD-L1 induces radiotherapy resistance through accelerating DNA damage repair (DDR). However, the disability of clinically used PD-L1 antibodies in inhibiting cytoplasm-distributed PD-L1 limits their effectiveness. Therefore, a nanoadjuvant is developed to sensitize cancer to radiotherapy via multi-level immunity activation through depressing PD-L1 and TGF-β1 by triphenylphosphine-derived metformin, and activating the cGAS-STING pathway by generating Mn2+ from MnO2 and producing more dsDNA via reversing tumor hypoxia and impairing DDR. Thus, Tpp-Met@MnO2@Alb effectively enhances the efficiency of radiotherapy to inhibit the progression of irradiated local and abscopal tumors and tumor lung metastases, offering a long-term memory of antitumor immunity without discernible side effects. Overall, Tpp-Met@MnO2@Alb has the potential to be clinically applied for overcoming radio-immunotherapy resistance.

Multitarget, multiagent PLGA nanoparticles for simultaneous tumor eradication and TME remodeling in a melanoma mouse model

Despite the fact that chemoimmunotherapy has emerged as a key component in the era of cancer immunotherapy, it is challenged by the complex tumor microenvironment (TME) that is jam-packed with cellular and non-cellular immunosuppressive components. The aim of this study was to design a nanoparticulate system capable of sufficiently accumulating in the tumor and spleen to mediate local and systemic immune responses, respectively. The study also aimed to remodel the immunosuppressive TME. For such reasons, multi-functional polylactic-co-glycolic acid (PLGA) nanoparticles (NPs) were engineered to simultaneously eradicate the cancer cells, silence the tumor-associated fibroblasts (TAFs), and re-educate the tumor-associated macrophages (TAMs) using doxorubicin, losartan, and metformin, respectively. These agents were also selected for their ability to tip the balance of the splenic immune cells towards immunostimulatory phenotypes. To establish TAM and TAF cultures, normal macrophages and fibroblasts were incubated with B16F10 melanoma cell (Mel)-derived secretome. Drug-loaded PLGA NPs were prepared, characterized, and tested in the target cell types. Organ distribution of fluorescein-loaded PLGA NPs was evaluated in a mouse model of melanoma. Finally, the local and systemic effects of different combination therapy programs were portrayed. The in vitro studies showed that the drug-loaded PLGA NPs could significantly ablate the immunosuppressive nature of Mel and skew TAMs and TAFs towards more favorable phenotypes. While in vivo, PLGA NPs were proven to exhibit long blood circulation time and to localize preferentially in the tumor and the spleen. The combination of either metformin or losartan with doxorubicin was superior to the monotherapy, both locally and systemically. However, the three-agent combo produced detrimental effects in the form of compromised well-being, immune depletion, and metastasis. These findings indicate the potential of TME remodeling as means to prime the tumors for successful chemoimmunotherapy. In addition, they shed light on the importance of the careful use of combination therapies and the necessity of employing dose-reduction strategies. D-NPs doxorubicin-loaded NPs, M-NPs metformin-loaded NPs, L-NPs losartan-loaded NPs, TAMs tumor-associated macrophages, TAFs tumor-associated fibroblasts, PD-L1 programmed death ligand 1, TNF-α tumor necrosis factor alpha, TGF-β transforming growth factor beta, CD206/40/86 cluster of differentiation 206/40/86, α-SMA alpha-smooth muscle actin, MMPs matrix metalloproteases.

Recent advances in drug delivery and targeting for the treatment of pancreatic cancer

Despite significant treatment efforts, pancreatic ductal adenocarcinoma (PDAC), the deadliest solid tumor, is still incurable in the preclinical stages due to multifacet stroma, dense desmoplasia, and immune regression. Additionally, tumor heterogeneity and metabolic changes are linked to low grade clinical translational outcomes, which has prompted the investigation of the mechanisms underlying chemoresistance and the creation of effective treatment approaches by selectively targeting genetic pathways. Since targeting upstream molecules in first-line oncogenic signaling pathways typically has little clinical impact, downstream signaling pathways have instead been targeted in both preclinical and clinical studies. In this review, we discuss how the complexity of various tumor microenvironment (TME) components and the oncogenic signaling pathways that they are connected to actively contribute to the development and spread of PDAC, as well as the ways that recent therapeutic approaches have been targeted to restore it. We also illustrate how many endogenous stimuli-responsive linker-based nanocarriers have recently been developed for the specific targeting of distinct oncogenes and their downstream signaling cascades as well as their ongoing clinical trials. We also discuss the present challenges, prospects, and difficulties in the development of first-line oncogene-targeting medicines for the treatment of pancreatic cancer patients.

Mitochondrial Disruption Nanosystem Simultaneously Depressed Programmed Death Ligand-1 and Transforming Growth Factor-β to Overcome Photodynamic Immunotherapy Resistance

Currently, limited photosensitizers possess the capacity to reverse tumor hypoxia and reduce programmed death ligand-1 (PD-L1) and transforming growth factor-β (TGF-β) expression simultaneously, hindering the perfect photodynamic therapy (PDT) effect due to acquired immune resistance and the tumor hypoxic microenvironment. To tackle these challenges, in this research, we demonstrated that mitochondrial energy metabolism depression can be utilized as an innovative and efficient approach for reducing the expression of PD-L1 and TGF-β simultaneously, which may offer a design strategy for a more ideal PDT nanosystem. Through proteomic analysis of 5637 cells, we revealed that tamoxifen (TMX) can incredibly regulate PD-L1 expression in tumor cells. Then, to selectively deliver clinically used mitochondrial energy metabolism depressant TMX to solid tumors as well as design an ideal PDT nanosystem, we synthesized MHI-TMX@ALB by combining a mitochondria-targeted heptamethine cyanine PDT-dye MHI with TMX through self-assembly with albumin (ALB). Interestingly enough, the MHI-TMX@ALB nanoparticle demonstrated effective reversion of tumor hypoxia and inhibition of PD-L1 protein expression at a lower dosage (7.5 times to TMX), which then enhanced the efficacy of photodynamic immunotherapy via enhancing T-cell infiltration. Apart from this, by leveraging the heptamethine dye's targeting capacity toward tumors and TMX's role in suppressing TGF-β, MHI-TMX@ALB also more effectively mitigated 4T1 tumor lung metastasis development. All in all, the MHI-TMX@ALB nanoparticle could be used as a multifunctional economical PD-L1 and TGF-β codepression immune-regulating strategy, broadening the potential clinical applications for a more ideal PDT nanosystem.

Biosynthesized tumor acidity and MMP dual-responsive plant toxin gelonin for robust cancer therapy

Among all kinds of anticancer agents, small molecule drugs produce an unsatisfactory therapeutic effect due to the lack of selectivity, notorious drug resistance and side effects. Therefore, researchers have begun to pay extensive attention to macromolecular drugs with high efficacy and specificity. As a plant toxin, gelonin exerts potent antitumor activity via inhibiting intracellular protein synthesis. However, gelonin lacks a translocation domain, and thus its poor cellular uptake leads to low outcomes of antitumor response. Here, tumor acidity and matrix metalloproteinase (MMP) dual-responsive functional gelonin (Trx-PVGLIG-pHLIP-gelonin, TPpG), composed of a thioredoxin (Trx) tag, a pH low insertion peptide (pHLIP), an MMP-responsive motif PVGLIG hexapeptide and gelonin, was innovatively proposed and biologically synthesized by a gene recombination technique. TPpG exhibited good thermal and serum stability, showed MMP responsiveness and could enter tumor cells under weakly acidic conditions, especially for MMP2-overexpressing HT1080 cells. Compared to low MMP2-expressing MCF-7 cells, TPpG displayed enhanced in vitro antitumor efficacy to HT1080 cells at pH 6.5 as determined by different methods. Likewise, TPpG was much more effective in triggering cell apoptosis and inhibiting protein synthesis in HT1080 cells than in MCF-7 cells. Intriguingly, with enhanced stability and pH/MMP dual responsiveness, TPpG notably inhibited subcutaneous HT1080 xenograft growth in mice and no noticeable off-target side effect was observed. This ingeniously designed strategy aims at providing new perspectives for the development of a smart platform that can intelligently respond to a tumor microenvironment for efficient protein delivery.

Immunofluorescence profiling of collagen subtypes is a predictor of treatment outcomes in pancreatic cancer

Desmoplasia in pancreatic ductal adenocarcinoma (PDAC) is characterized by elevated levels of tumor collagen. Desmoplasia restricts drug delivery in PDAC, contributes to treatment resistance, and is associated with poor survival outcomes. We have previously shown that photodynamic therapy (PDT)-based treatment remediates desmoplasia in orthotopic PDAC tumors by reducing second harmonic generation signals from collagen by >90% and by reducing collagen alignment by >103-fold [19]. Remediating desmoplasia correlated with improved survival outcomes in mice. To understand this phenomenon at a fundamental level, it is important to dissect the impact of therapy on collagen subtypes. In this study, we demonstrate that immunofluorescence profiling of collagen subtypes I, II, III and IV in PDAC tumors 72 h following multiple treatment regimens is predictive of long-term outcomes. Treatment regimens include nanoliposomal irinotecan chemotherapy (nal-IRI; akin to ONIVYDE™), a combination of nal-IRI chemotherapy with PDT encapsulated in a single photoactivable multi-inhibitor liposome (PMIL) and an EGFR-targeted PMIL construct (TPMIL). Results show that the relative tumor content of collagen I, II and III was inversely correlated with overall survival (P ≤ 0.0013, P ≤ 0.0001, P ≤ 0.0011, respectively), while, surprisingly, the relative tumor content of collagen IV was directly correlated with overall survival (P ≤ 0.0001). Similar relationships were observed between the relative tumor content of collagen subtypes and the residual tumor volume at day 88 following treatment. Considering that the relationship between collagen subtypes and treatment outcomes is observed across multiple treatment regimens, immunofluorescence profiling at 72 h following treatment appears to be predictive of tumor growth inhibition and survival in PDAC. Early immunofluorescence collagen subtype profiling may therefore aid in treatment personalization and may inform the dosimetry and scheduling of combination regimens for PDAC, such as chemotherapy and emerging PDT-based combinations, to maximize patient survival benefit.

Dendritic Nanomedicine with Boronate Bonds for Augmented Chemo-Immunotherapy via Synergistic Modulation of Tumor Immune Microenvironment

Unsatisfied tumor accumulation of chemotherapeutic drugs and a complicated immunosuppressive microenvironment diminish the immune response rate and the therapeutic effect. Surface modification of these drugs with target ligands can promote their cellular internalization, but the modified drugs may be subjected to unexpected immune recognition and clearance. Herein, a phenylboronic acid (PBA) group-shieldable dendritic nanomedicine that integrates an immunogenic cell death (ICD)-inducing agent (epirubicin, Epi) and an indoleamine 2,3-dioxgenase 1 (IDO1) inhibitor (NLG919) is reported for tumor chemo-immunotherapy. This NLG919-loaded Epi-conjugated PEGylated dendrimers bridged with boronate bonds (NLG919@Epi-DBP) maintains a stable nanostructure during circulation. Under a moderate acidic condition, the PBA group exposes to the sialic acid residue on the tumor cell membrane to enhance the internalization and penetration of NLG919@Epi-DBP. At pH 5.0, NLG919@Epi-DBP rapidly disassembles to release the incorporated Epi and NLG919. Epi triggers robust ICD of tumor cells that evokes strong immune response. In addition, inhibition of the IDO1 activity downregulates the metabolism of L-tryptophan to kynurenine, leading to a reduction in the recruitment of immunosuppressive cells and modulation of the tumor immune microenvironment. Collectively, this promising strategy has been demonstrated to evoke robust immune response as well as remodel the immunosuppressive microenvironment for an enhanced chemo-immunotherapeutic effect.

Photo-Triggered Cascade Therapy: A NIR-II AIE Luminogen Collaborating with Nitric Oxide Facilitates Efficient Collagen Depletion for Boosting Pancreatic Cancer Phototheranostics

The dense extracellular matrix (ECM) in the pancreatic cancer severely hampers the penetration of nanodrugs, which causes inferior therapeutic efficacy. To address this issue, a multifunctional liposome, namely, Lip-DTI/NO, integrating a type-I photosensitizer DTITBT with glutathione (GSH) or heat-responsive nitric oxide (NO) donor S-nitroso-N-acetyl-D-penicillamine (SNAP) is constructed to deplete the tumor ECM, leading to enhanced drug delivery and consequently improved phototherapy. The loaded DTITBT possesses multiple functions including NIR-II fluorescence imaging, efficient superoxide radical (O2 •- ) generation and excellent photothermal conversion efficiency, making it feasible for precisely pinpointing the tumor in the phototherapy process. Responding to the intracellular overexpressed glutathione or heat produced by photothermal effect of DTITBT, NO can be released from SNAP. Upon 808 nm laser irradiation, Lip-DTI/NO could selectively induce in situ generation of peroxynitrite anion (ONOO- ) in tumor after cascade processes including O2 •- production, GSH or heat-triggered NO release, and rapid reaction between O2 •- and NO. The generated ONOO- could activate the expression of endogenous matrix metalloproteinases which could efficiently digest collagen of tumor ECM, thus facilitating enhanced penetration and accumulation of Lip-DTI/NO in tumor. In vivo evaluation demonstrates the notable therapeutic efficacy via ONOO- -potentiated synergistic photodynamic-photothermal therapies on both subcutaneous and orthotopic pancreatic cancer model.

Advances in Brain Tumor Therapy Based on the Magnetic Nanoparticles

Brain tumors, including primary gliomas and brain metastases, are one of the deadliest tumors because effective macromolecular antitumor drugs cannot easily penetrate the blood-brain barrier (BBB) and blood-brain tumor barrier (BTB). Magnetic nanoparticles (MNPs) are considered the most suitable nanocarriers for the delivery of brain tumor drugs because of their unique properties compared to other nanoparticles. Numerous preclinical and clinical studies have demonstrated the potential of these nanoparticles in magnetic targeting, nuclear magnetic resonance, magnetic thermal therapy, and ultrasonic hyperthermia. To further develop and optimize MNPs for the diagnosis and treatment of brain tumors, we attempt to outline recent advances in the use of MNPs to deliver drugs, with a particular focus on their efficacy in the delivery of anti-brain tumor drugs based on magnetic targeting and low-intensity focused ultrasound, magnetic resonance imaging for surgical real-time guidance, and magnetothermal and ultrasonic hyperthermia therapy. Furthermore, we summarize recent findings on the clinical application of MNPs and the research limitations that need to be addressed in clinical translation.

Box Behnken optimization of cubosomes for enhancing the anticancer activity of metformin: Design, characterization, and in-vitro cell proliferation assay on MDA-MB-231 breast and LOVO colon cancer cell lines

This study aimed to formulate and statistically optimize cubosomal formulations of metformin (MTF) to enhance its breast anticancer activity. A Box Behnken design was employed using Design-Expert® software. The formulation variables were glyceryl monooleate concentration (GMO) w/w%, Pluronic F-127 concentration (PF127) w/w% and Tween 80 concentration w/w% whereas Entrapment efficiency (EE%), Vesicles' size (VS) and Zeta potential (ZP) were set as the dependent responses. The design expert software was used to perform the process of optimization numerically. X ray diffraction (XRD), Transmission electron microscope (TEM), in-vitro release study, short-term stability study, and in in-vitro cell proliferation assay on the MDA-MB-231 breast cancer and LOVO cancer cell lines were used to validate the optimized cubosomal formulation. The optimized formulation had a composition of 4.35616 (w/w%) GMO, 5 (w/w%) PF127 and 7.444E-6 (w/w%) Tween 80 with a desirability of 0.733. The predicted values for EE%, VS and ZP were 78.0592%, 307.273 nm and - 26.8275 mV, respectively. The validation process carried out on the optimized formula revealed that there were less than a 5% variance from the predicted responses. The XRD thermograms showed that MTF was encapsulated inside the cubosomal vesicles. TEM images of the optimized MTF cubosomal formulation showed spherical non-aggregated nanovesicles. Moreover, it revealed a sustained release profile of MTF in comparison to the MTF solution. Stability studies indicated that optimum cubosomal formulation was stable for thirty days. Cytotoxicity of the optimized cubosomal formulation was enhanced on the MDA-MB-231 breast and LOVO cancer cell lines compared to MTF solution even at lower concentrations. However, it showed superior cytotoxic effect on breast cancer cell line. So, cubosomes could be considered a promising carrier of MTF to treat breast and colon cancers.

Sono-Activatable Semiconducting Polymer Nanoreshapers Multiply Remodel Tumor Microenvironment for Potent Immunotherapy of Orthotopic Pancreatic Cancer

Due to the complicated tumor microenvironment that compromises the efficacies of various therapies, the effective treatment of pancreatic cancer remains a big challenge. Sono-activatable semiconducting polymer nanoreshapers (SPNDN H) are constructed to multiply remodel tumor microenvironment of orthotopic pancreatic cancer for potent immunotherapy. SPNDN H contain a semiconducting polymer, hydrogen sulfide (H2 S) donor, and indoleamine 2,3-dioxygenase (IDO) inhibitor (NLG919), which are encapsulated by singlet oxygen (1 O2 )-responsive shells with modification of hyaluronidase (HAase). After accumulation in orthotopic pancreatic tumor sites, SPNDN H degrade the major content of tumor microenvironment hyaluronic acid to promote nanoparticle enrichment and immune cell infiltration, and also release H2 S to relieve tumor hypoxia via inhibiting mitochondrion functions. Moreover, the relieved hypoxia enables amplified sonodynamic therapy (SDT) under ultrasound (US) irradiation with generation of 1 O2 , which leads to immunogenic cell death (ICD) and destruction of 1 O2 -responsive components to realize sono-activatable NLG919 release for reversing IDO-based immunosuppression. Through such a multiple remodeling mechanism, a potent antitumor immunological effect is triggered after SPNDN H-based treatment. Therefore, the growths of orthotopic pancreatic tumors in mouse models are almost inhibited and tumor metastases are effectively restricted. This study offers a sono-activatable nanoplatform to multiply remodel tumor microenvironment for effective and precise immunotherapy of deep-tissue orthotopic tumors.

Nanomedicine Strategies in Conquering and Utilizing the Cancer Hypoxia Environment

Cancer with a complex pathological process is a major disease to human welfare. Due to the imbalance between oxygen (O2) supply and consumption, hypoxia is a natural characteristic of most solid tumors and an important obstacle for cancer therapy, which is closely related to tumor proliferation, metastasis, and invasion. Various strategies to exploit the feature of tumor hypoxia have been developed in the past decade, which can be used to alleviate tumor hypoxia, or utilize the hypoxia for targeted delivery and diagnostic imaging. The strategies to alleviate tumor hypoxia include delivering O2, in situ O2 generation, reprogramming the tumor vascular system, decreasing O2 consumption, and inhibiting HIF-1 related pathways. On the other side, hypoxia can also be utilized for hypoxia-responsive chemical construction and hypoxia-active prodrug-based strategies. Taking advantage of hypoxia in the tumor region, a number of methods have been applied to identify and keep track of changes in tumor hypoxia. Herein, we thoroughly review the recent progress of nanomedicine strategies in both conquering and utilizing hypoxia to combat cancer and put forward the prospect of emerging nanomaterials for future clinical transformation, which hopes to provide perspectives in nanomaterials design.

A nanodrug simultaneously inhibits pancreatic stellate cell activation and regulatory T cell infiltration to promote the immunotherapy of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a dense extracellular matrix flooded with immune suppressive cells, resulting in extremely poor clinical response to immunotherapy. It has been revealed that the activation of pancreatic stellate cells (PSCs) makes considerable contributions to the immunological "cold" tumor microenvironment (TME). Herein, we developed a polyamino acid-based nanodrug incorporating the PSC activation inhibitor calcipotriol and anti-CXCL12 siRNA. The nanodrug was easily prepared with a small particle size and is capable of penetrating pancreatic tumors to inactivate PSCs and downregulate CXCL12. The in vivo results of orthotopic pancreatic tumor treatment demonstrated that codelivery of calcipotriol and anti-CXCL12 siRNA remodeled the PDAC TME with reduced extracellular matrix and decreased immunosuppressive T cells. Eventually, the infiltration of cytotoxic T cells was increased, thereby acting with immune checkpoint blockade (ICB) therapy for immunologically "cold" pancreatic tumors. In the present study, we propose a promising paradigm to improve the immunotherapy outcome of PDAC using nanodrugs that synchronously inhibit PSC activation and regulatory T-cell infiltration. STATEMENT OF SIGNIFICANCE: Pancreatic ductal adenocarcinoma (PDAC) is characterized by a dense extracellular matrix (ECM) that impedes the tumor infiltration of therapeutic agents and cytotoxic T lymphocytes, resulting in a poor clinical response to immunotherapy. In the present study, we proposed a promising approach for enhanced immunotherapy of pancreatic cancer. Specifically, a nanodrug incorporating calcipotriol and anti-CXCL12 siRNA was synthesized to synchronously inactivate matrix-producing pancreatic stellate cells and suppress the infiltration of regulatory T cells. The reduced ECM removed the pathological barrier, preventing nanodrug penetration and effector T-cell infiltration, leading to a conversion of the immunosuppressive "cold" microenvironment to a "hot" microenvironment, which eventually boosted the immunotherapy of anti-PD-1 antibodies in pancreatic cancer.

Nanomedicine and epigenetics: New alliances to increase the odds in pancreatic cancer survival

Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest cancers worldwide, primarily due to its robust desmoplastic stroma and immunosuppressive tumor microenvironment (TME), which facilitate tumor progression and metastasis. In addition, fibrous tissue leads to sparse vasculature, high interstitial fluid pressure, and hypoxia, thereby hindering effective systemic drug delivery and immune cell infiltration. Thus, remodeling the TME to enhance tumor perfusion, increase drug retention, and reverse immunosuppression has become a key therapeutic strategy. In recent years, targeting epigenetic pathways has emerged as a promising approach to overcome tumor immunosuppression and cancer progression. Moreover, the progress in nanotechnology has provided new opportunities for enhancing the efficacy of conventional and epigenetic drugs. Nano-based drug delivery systems (NDDSs) offer several advantages, including improved drug pharmacokinetics, enhanced tumor penetration, and reduced systemic toxicity. Smart NDDSs enable precise targeting of stromal components and augment the effectiveness of immunotherapy through multiple drug delivery options. This review offers an overview of the latest nano-based approaches developed to achieve superior therapeutic efficacy and overcome drug resistance. We specifically focus on the TME and epigenetic-targeted therapies in the context of PDAC, discussing the advantages and limitations of current strategies while highlighting promising new developments. By emphasizing the immense potential of NDDSs in improving therapeutic outcomes in PDAC, our review paves the way for future research in this rapidly evolving field.

Revisiting Circulating Extracellular Matrix Fragments as Disease Markers in Myelofibrosis and Related Neoplasms

Philadelphia chromosome-negative chronic myeloproliferative neoplasms (MPNs) arise due to acquired somatic driver mutations in stem cells and develop over 10-30 years from the earliest cancer stages (essential thrombocythemia, polycythemia vera) towards the advanced myelofibrosis stage with bone marrow failure. The JAK2V617F mutation is the most prevalent driver mutation. Chronic inflammation is considered to be a major pathogenetic player, both as a trigger of MPN development and as a driver of disease progression. Chronic inflammation in MPNs is characterized by persistent connective tissue remodeling, which leads to organ dysfunction and ultimately, organ failure, due to excessive accumulation of extracellular matrix (ECM). Considering that MPNs are acquired clonal stem cell diseases developing in an inflammatory microenvironment in which the hematopoietic cell populations are progressively replaced by stromal proliferation-"a wound that never heals"-we herein aim to provide a comprehensive review of previous promising research in the field of circulating ECM fragments in the diagnosis, treatment and monitoring of MPNs. We address the rationales and highlight new perspectives for the use of circulating ECM protein fragments as biologically plausible, noninvasive disease markers in the management of MPNs.

Nanomedicine Strategies for Targeting Tumor Stroma

The tumor stroma, or the microenvironment surrounding solid tumors, can significantly impact the effectiveness of cancer therapies. The tumor microenvironment is characterized by high interstitial pressure, a consequence of leaky vasculature, and dense stroma created by excessive deposition of various macromolecules such as collagen, fibronectin, and hyaluronic acid (HA). In addition, non-cancerous cells such as cancer-associated fibroblasts (CAFs) and the extracellular matrix (ECM) itself can promote tumor growth. In recent years, there has been increased interest in combining standard cancer treatments with stromal-targeting strategies or stromal modulators to improve therapeutic outcomes. Furthermore, the use of nanomedicine, which can improve the delivery and retention of drugs in the tumor, has been proposed to target the stroma. This review focuses on how different stromal components contribute to tumor progression and impede chemotherapeutic delivery. Additionally, this review highlights recent advancements in nanomedicine-based stromal modulation and discusses potential future directions for developing more effective stroma-targeted cancer therapies.

Fibroblast Activation Protein-Targeted Photodynamic Therapy of Cancer-Associated Fibroblasts in Murine Models for Pancreatic Ductal Adenocarcinoma

Patients with pancreatic ductal adenocarcinoma (PDAC) have a dismal 5 year survival of 9%. One important limiting factor for treatment efficacy is the dense tumor-supporting stroma. The cancer-associated fibroblasts in this stroma deposit excessive amounts of extracellular matrix components and anti-inflammatory mediators, which hampers the efficacy of chemo- and immunotherapies. Systemic depletion of all activated fibroblasts is, however, not feasible nor desirable and therefore a local approach should be pursued. Here, we provide a proof-of-principle of using fibroblast activation protein (FAP)-targeted photodynamic therapy (tPDT) to treat PDAC. FAP-targeting antibody 28H1 and irrelevant control antibody DP47GS were conjugated to the photosensitizer IRDye700DX (700DX) and the chelator diethylenetriaminepentaacetic acid. In vitro binding and cytotoxicity were evaluated using the fibroblast cell-line NIH-3T3 stably transfected with FAP. Biodistribution of 111In-labeled antibody-700DX constructs was determined in mice carrying syngeneic tumors of the murine PDAC cell line PDAC299, and in a genetically engineered PDAC mouse model (CKP). Then, tPDT was performed by exposing the subcutaneous or the spontaneous PDAC tumors to 690 nm light. Induction of apoptosis after treatment was assessed using automated analyses of immunohistochemistry for cleaved caspase-3. 28H1-700DX effectively bound to 3T3-FAP cells and induced cytotoxicity upon exposure to 690 nm light, whereas no binding or cytotoxic effects were observed for DP47GS-700DX. Although both 28H1-700DX and DP47GS-700DX accumulated in subcutaneous PDAC299 tumors, autoradiography demonstrated that only 28H1-700DX reached the tumor core. On the contrary, control antibody DP47GS-700DX was only present at the tumor rim. In CKP mice, both antibodies accumulated in the tumor, but tumor-to-blood ratios of 28H1-700DX were higher than that of the control. Notably, in vivo FAP-tPDT caused upregulation of cleaved caspase-3 staining in both subcutaneous and in spontaneous tumors. In conclusion, we have shown that tPDT is a feasible approach for local depletion of FAP-expressing stromal cells in murine models for PDAC.

Murine Breast Cancer Radiosensitization Using Oxygen Microbubbles and Metformin: Vessels Are the Key

Radiotherapy is a cornerstone of cancer treatment, but tumor hypoxia and resistance to radiation remain significant challenges. Vascular normalization has emerged as a strategy to improve oxygenation and enhance therapeutic outcomes. In this study, we examine the radiosensitization potential of vascular normalization using metformin, a widely used anti-diabetic drug, and oxygen microbubbles (OMBs). We investigated the synergistic action of metformin and OMBs and the impact of this therapeutic combination on the vasculature, oxygenation, invasiveness, and radiosensitivity of murine 4T1 breast cancer. We employed in vivo Doppler ultrasonographic imaging for vasculature analysis, electron paramagnetic resonance oximetry, and immunohistochemical assessment of microvessels, perfusion, and invasiveness markers. Our findings demonstrate that both two-week metformin therapy and oxygen microbubble treatment normalize abnormal cancer vasculature. The combination of metformin and OMB yielded more pronounced and sustained effects than either treatment alone. The investigated therapy protocols led to nearly twice the radiosensitivity of 4T1 tumors; however, no significant differences in radiosensitivity were observed between the various treatment groups. Despite these improvements, resistance to treatment inevitably emerged, leading to the recurrence of hypoxia and an increased incidence of metastasis.

Cell-Penetrating Peptide-Based Delivery of Macromolecular Drugs: Development, Strategies, and Progress

Cell-penetrating peptides (CPPs), developed for more than 30 years, are still being extensively studied due to their excellent delivery performance. Compared with other delivery vehicles, CPPs hold promise for delivering different types of drugs. Here, we review the development process of CPPs and summarize the composition and classification of the CPP-based delivery systems, cellular uptake mechanisms, influencing factors, and biological barriers. We also summarize the optimization routes of CPP-based macromolecular drug delivery from stability and targeting perspectives. Strategies for enhanced endosomal escape, which prolong its half-life in blood, improved targeting efficiency and stimuli-responsive design are comprehensively summarized for CPP-based macromolecule delivery. Finally, after concluding the clinical trials of CPP-based drug delivery systems, we extracted the necessary conditions for a successful CPP-based delivery system. This review provides the latest framework for the CPP-based delivery of macromolecular drugs and summarizes the optimized strategies to improve delivery efficiency.

Glypican1: a potential cancer biomarker for nanotargeted therapy

Glypicans (GPCs) are generally involved in cellular signaling, growth and proliferation. Previous studies reported their roles in cancer proliferation. GPC1 is a co-receptor for a variety of growth-related ligands, thereby stimulating the tumor microenvironment by promoting angiogenesis and epithelial-mesenchymal transition (EMT). This work reviews GPC1-biomarker-assisted drug discovery by the application of nanostructured materials, creating nanotheragnostics for targeted delivery and application in liquid biopsies. The review includes details of GPC1 as a potential biomarker in cancer progression as well as a potential candidate for nano-mediated drug discovery.