Tumor Penetration Ability Research Articles

"Cluster Bomb" Based on Redox-Responsive Carbon Dot Nanoclusters Coated with Cell Membranes for Enhanced Tumor Theranostics.

Designing intelligent stimuli-responsive nanoplatforms that are integrated with a biological membrane system and nanomaterials to realize efficient imaging and therapy of tumors still remains to be challenging. Herein, we report a unique strategy to prepare redox-responsive yellow fluorescent carbon dot nanoclusters (y-CDCs) loaded with anticancer drug doxorubicin (DOX) and coated with the cancer cell membrane (CCM) for precision fluorescence imaging and homologous targeting chemotherapy of tumors. The y-CDs with a size of 7.2 nm were first synthesized via a hydrothermal method and crosslinked to obtain redox-responsive y-CDCs with a size of 150.0 nm. The formulated y-CDCs were physically loaded with DOX with an efficiency of up to 81.0% and coated with CCM to endow them with antifouling properties, immune escape ability to escape from macrophage uptake, and homologous targeting capability to cancer cells. Within the reductive tumor microenvironment, the y-CDCs with quenched fluorescence can dissociate to form single y-CDs with recovered fluorescence and improved tumor penetration ability and simultaneously release DOX from the "cluster bomb", thus realizing efficient targeted tumor fluorescence imaging and chemotherapy. The designed y-CDCs/DOX@CCM may represent an updated nanomedicine formulation based on CDs for improved theranostics of different types of tumors.

Effect of Cationic Charge Density on Transcytosis of Polyethylenimine.

The adsorption-mediated transcytosis (AMT) induced by the electrostatic interaction between the positively charged surface of carriers and negatively charged cell membrane is a new paradigm enabling nanomedicine's tumor extravasation and infiltration. However, little is known about the correlation between the carrier's charge density and its AMT-induced tumor infiltration efficiency. Herein, we investigate the effect of the cationic polymer's charge on the AMT-induced tumor penetration ability using in vitro multilayer tumor spheroids (MTSs). A cationic polymer, polyethylenimine (PEI), is amidized with acetic anhydride to obtain acetylated PEIs (AcPEIs) with different cationic charge densities. As the amidization ratio increases, the AcPEIs' cytotoxicity, zeta potential, and cell-binding affinity significantly decrease. Notably, not only does the weak cell binding (AcPEIs with high acetylation degrees) lead to slow endocytosis and inefficient transcytosis, so does the strong cell-binding PEI. The PEI with 24% acetylation (AcPEI24%) is found to have the highest transcytosis efficiency because its balanced cell-binding affinity triggers fast adsorption-mediated endocytosis. The subsequent Golgi apparatus/endoplasmic reticulum-mediated exocytosis via extracellular vesicles leads to highly effective transcellular delivery and tumor penetration in MTSs. Therefore, the drug carrier's surface cationic charge density critically influences its AMT-induced tumor penetration efficiency. This study provides mechanistic insights into the design of drug-delivery systems with active transcytosis for improved tumor penetration and enhanced therapeutic efficiency.

A nanosensitizer self-assembled from oleanolic acid and chlorin e6 for synergistic chemo/sono-photodynamic cancer therapy

BackgroundSono-photodynamic therapy (SPDT) which is the combination of photodynamic therapy (PDT) and sonodynamic therapy (SDT), could exert much better anti-cancer effects than monotherapy. The combination of chemotherapy and PDT or SDT has shown great potential for cancer treatment. However, the combination of SPDT and chemotherapy for cancer treatment is rarely explored. PurposeWe utilized a natural hydrophobic anti-cancer drug oleanolic acid (OA) and a photosensitizer chlorin e6 (Ce6) through self-assembly technology to form a carrier-free nanosensitizer OC for combined chemotherapy and SPDT for cancer treatment. No studies involving using carrier-free nanomedicine for combined chemotherapy/SPDT have been reported yet. Study designAfter fully characterization of OC, the in vitro and in vivo anti-cancer activities of OC were investigated and the mechanisms of the synergistic therapeutic effects were studied. MethodsOC were synthesized through self-assembly technology and characterized by dynamic light scattering (DLS) and an atomic force microscope (AFM). Confocal microscope was used to investigate the intracellular uptake efficiency and the penetration ability of OC. The cell viability of PC9 and 4T1 cells treated with OC under laser and ultrasound (US) irradiation was determined by MTT assay. Furthermore, flow cytometry was performed to detect the reactive oxygen species (ROS) generation, loss of mitochondrial membrane potential (MMP), cell apoptosis and cell cycle arrest. Finally, the anti-tumor therapeutic efficacy of OC was investigated in orthotopic 4T1 breast tumor-bearing mouse model. ResultsOC showed an average particle size of around 100 nm with excellent light stability. OC increased more than 23 times accumulation of Ce6 in cancer cells and had strong tumor penetration ability in three-dimensional (3D) multicellular tumor spheroids (MCTSs). Compared with other therapeutic options, OC showed obvious synergistic inhibitory effects under light and US irradiation in PC9 and 4T1 cells with a significant decrease in IC50 values. Mechanism studies showed that OC could generate high ROS, induce MMP loss, and cause apoptosis and cell cycle arrest. In vivo studies also approved the synergistic therapeutic effects of OC in 4T1 mouse models. ConclusionSelf-assembled carrier-free nanosensitizer OC could be a promising therapeutic agent for synergistic chemo/sono-photodynamic therapy for cancer treatment.

Charge-reversal biodegradable MSNs for tumor synergetic chemo/photothermal and visualized therapy

Given the difficulties of biodegradation of mesoporous silica nanoparticles (NPs), enrichment and penetration of tumor sites, and real-time monitoring of the treatment process, we developed a kind of mannose-doping doxorubicin-loading mesoporous silica nanoparticle (MSN-Man-DOX) and coated by polydopamine-Gd3+ (PDAGd) metal-phenolic networks, as well as modified by poly (2-Ethyl-2-Oxazoline) (PEOz), constructing a novel nanomedicine MSN-Man-DOX@PDA-Gd-PEOz. Its pH-responsive charge reversal, photothermal, biodegradation, drug release, and magnetic resonance imaging (MRI) properties were evaluated in vitro. Cellular uptake, tumor penetration, lysosomal escape properties, as well as cell safety and toxicity of the nanoplatform were investigated through cell experiments. Finally, the MRI, organ distribution, photothermal condition, and comprehensive anti-tumor therapy in vivo were evaluated comprehensively through animal experiments. Research results showed that MSN-Man-DOX@PDA-Gd-PEOz had outstanding tumor enrichment and penetration abilities, which can produce excellent treatment effects through the synergistic effect of chemotherapy and photothermal therapy (PTT) with the function of magnetic resonance imaging contrast agent for disease monitoring. Besides, after finishing the therapeutic effect MSN-Man-DOX@PDA-Gd-PEOz can be biodegraded, so it had a good prospect of clinical application.

Tumor-Penetrable Nitric Oxide-Releasing Nanoparticles Potentiate Local Antimelanoma Therapy.

Although nitric oxide (NO) has been emerging as a novel local anticancer agent because of its potent cytotoxic effects and lack of off-target side effects, its clinical applications remain a challenge because of the short effective diffusion distance of NO that limits its anticancer activity. In this study, we synthesized albumin-coated poly(lactic-co-glycolic acid) (PLGA)-conjugated linear polyethylenimine diazeniumdiolate (LP/NO) nanoparticles (Alb-PLP/NO NPs) that possess tumor-penetrating and NO-releasing properties for an effective local treatment of melanoma. Sufficient NO-loading and prolonged NO-releasing characteristics of Alb-PLP/NO NPs were acquired through PLGA-conjugated LP/NO copolymer (PLP/NO) synthesis, followed by nanoparticle fabrication. In addition, tumor penetration ability was rendered by the electrostatic adsorption of the albumin on the surface of the nanoparticles. The Alb-PLP/NO NPs showed enhanced intracellular NO delivery efficiency and cytotoxicity to B16F10 murine melanoma cells. In B16F10-tumor-bearing mice, the Alb-PLP/NO NPs showed improved extracellular matrix penetration and spatial distribution in the tumor tissue after intratumoral injection, resulting in enhanced antitumor activity. Taken together, the results suggest that Alb-PLP/NO NPs represent a promising new modality for the local treatment of melanoma.

Stimuli-Responsive and Highly Penetrable Nanoparticles as a Multifunctional Nanoplatform for Boosting Nonsmall Cell Lung Cancer siRNA Therapy.

In cancer therapy, it is acknowledged that large-size nanoparticles stay in the circulation system for a long time, but their permeability to tumor tissues is poor. To address the conflicting need for prolonging circulation time and favorable tumor tissue penetration ability, a charge conversional multifunctional nanoplatform was strategically designed to improve the efficacy of small interfering RNA (siRNA) therapy against nonsmall cell lung cancer (NSCLC). The development of nanodrug delivery systems (NDDSs) was constructed by loading siRNA on polyamidoamine (PAMAM) dendrimers to build small-sized PAM/siRNA via electrostatic interaction and then capped with a pH-triggered copolymer poly(ethylene glycol) methyl ether (mPEG)-poly-l-lysine (PLL)-2,3-dimethylmaleic anhydride (DMA) (shorted as PLM) under physiological conditions. While in the tumor microenvironment, the acidic reaction of the PLM copolymer changes from negative charge to positive charge due to the cleavable amide bond between mPEG-PLL and DMA, leading to large-size nanoparticles (NPs) with a negative charge that turns into a positive charge and small NPs with a high tumor-penetrating ability. All of the in vitro and in vivo studies validated that PLM/PAM/siRNA NPs possess desirable features including excellent biocompatibility, a prolonged circulation time, significant pH sensitivity, high tumor tissue penetration ability, and sufficient endo-/lysosomal escape. Taken together, all results suggest tremendous potential of the gene therapy based on the stimuli-sensitive PLM/PAM/siRNA NPs, providing a profound application prospective treatment strategy in cancer gene therapy.

Active stealth and self-positioning biomimetic vehicles achieved effective antitumor therapy

Mesenchymal stem cells (MSCs) are recognized as promising drug delivery vehicles. However, the limitation of drug loading capacity and safety considerations are two obstacles to the further application of MSCs. Here, we report MSC membrane-coated mesoporous silica nanoparticles (MSN@M) that maintain the active stealth and self-positioning drug delivery abilities of MSCs and resolve issues related to MSCs-mediated drug delivery. MSN@M was established through uniformly integrating MSC membrane onto a mesoporous silica nanoparticle (MSN) core by sonication. Reduced clearance of phagocytes mediated by CD47 marker on MSC membrane was observed in vitro, which explained the only ~ 25% clearance rate of MSN@M compared with MSN in vivo within 24 h. MSN@M also showed stronger tumor targeting and penetration ability compared with MSN in HepG2 tumor bearing mice. Simultaneously, MSN@M exhibited strong capacity for drug loading and sustained drug release ability of MSN when loaded with doxorubicin (DOX), the drug loading of MSN@M increased ~ 5 folds compared with MSC membrane. In HepG2 xenograft mice, DOX-loaded MSN@M effectively inhibited the growth of tumors and decreased the side effects of treatment by decreasing the exposure of other tissues to DOX. Consequently, our MSN@M may serve as alternative vehicles for MSCs and provide more options for antitumor treatment.

Morphology/Interstitial Fluid Pressure-Tunable Nanopomegranate Designed by Alteration of Membrane Fluidity under Tumor Enzyme and PEGylation.

Up to now, insufficient drug accumulation in tumor remains a major challenge for nanochemotherapy. However, the spherical nanocarriers with large diameter, which are beneficial for blood circulation and tumor extravasation, cannot travel deep in a tumor. Additionally, high tumor interstitial fluid pressure (IFP) in the tumor microenvironment may promote the efflux of the penetrable nanodrugs. Therefore, the size and shape of nanocarriers as well as the tumoral IFP can be regulated synchronously for improved tumor penetration and combined chemotherapy. Herein, a novel dual-functional polymer-polypeptide (Biotin-PEG2000-GKGPRQITITK) for both verified tumor targeting and responsiveness was synthesized to construct the "peel" of nanopomegranate-like nanovectors (DI-MPL), in which docetaxel-loaded micelles was encapsulated as "seeds". Interestingly, DI-MPL was endowed multi-abilities of tunable size/shape switch and controlled release of IFP alleviator imatinib (IM), which were developed with one and the same strategy-alteration of membrane fluidity under the cleavage of polymer-polypeptide and PEGylation. As a result, the peel of DI-MPL could turn into small pieces with the seed scattered out in response to matrix metalloproteinase-9 (MMP-9), making nanopomegranate (180 nm) switch into spheres/disks (40 nm), during which IM is released to reduce IFP synchronously. With prominent tumor penetration ability in both multicellular tumor spheroids (MCTS) and tumor tissue, DI-MPL exhibited optimal inhibition of MCTS growth and the enhanced chemotherapy in comparison to other preparations. Meanwhile, the improved penetrability of DI-MPL in tumor tissue was found to be related to the reduced IFP, which is achieved via inhibiting expression of phosphorylated platelet-derived growth factor receptor-β (p-PDGFR-β) by IM. Altogether, the bilateral adjusting strategies from nanocarrier size/shape and tumoral IFP with a single enzyme-responsive material could provide a potential combined chemotherapy to improve tumor penetration.

Cellular Internalization and Inhibition Capacity of New Anti-Glioma Peptide Conjugates: Physicochemical Characterization and Evaluation on Various Monolayer- and 3D-Spheroid-Based in Vitro Platforms.

Most therapeutic agents used for treating brain malignancies face hindered transport through the blood-brain barrier (BBB) and poor tissue penetration. To overcome these problems, we developed peptide conjugates of conventional and experimental anticancer agents. SynB3 cell-penetrating peptide derivatives were applied that can cross the BBB. Tuftsin derivatives were used to target the neuropilin-1 transport system for selectivity and better tumor penetration. Moreover, SynB3-tuftsin tandem compounds were synthesized to combine the beneficial properties of these peptides. Most of the conjugates showed high and selective efficacy against glioblastoma cells. SynB3 and tandem derivatives demonstrated superior cellular internalization. The penetration profile of the conjugates was determined on a lipid monolayer and Transwell co-culture system with noncontact HUVEC-U87 monolayers as simple ex vivo and in vitro BBB models. Importantly, in 3D spheroids, daunomycin-peptide conjugates possessed a better tumor penetration ability than daunomycin. These conjugates are promising tools for the delivery systems with tunable features.

Nucleolin-Targeting AS1411 Aptamer-Modified Micelle for the Co-Delivery of Doxorubicin and miR-519c to Improve the Therapeutic Efficacy in Hepatocellular Carcinoma Treatment.

BackgroundMultidrug resistance (MDR) has emerged to be a major hindrance in cancer therapy, which contributes to the reduced sensitivity of cancer cells toward chemotherapeutic drugs mainly owing to the over-expression of drug efflux transporters. The combination of gene therapy and chemotherapy has been considered as a potential approach to improve the anti-cancer efficacy by reversing the MDR effect.Materials and MethodsThe AS1411 aptamer-functionalized micelles were constructed through an emulsion/solvent evaporation strategy for the simultaneous co-delivery of doxorubicin and miR-519c. The therapeutic efficacy and related mechanism of micelles were explored based on the in vitro and in vivo active targeting ability and the suppression of MDR, using hepatocellular carcinoma cell line HepG2 as a model.ResultsThe micelle was demonstrated to possess favorable cellular uptake and tumor penetration ability by specifically recognizing the nucleolin in an AS1411 aptamer-dependent manner. Further, the intracellular accumulation of doxorubicin was significantly improved due to the suppression of ABCG2-mediated drug efflux by miR-519c, resulting in the efficient inhibition of tumor growth.ConclusionThe micelle-mediated co-delivery of doxorubicin and miR-519c provided a promising strategy to obtain ideal anti-cancer efficacy through the active targeting function and the reversion of MDR.

A hybrid nanozymes in situ oxygen supply synergistic photothermal/chemotherapy of cancer management.

Hypoxia in the solid tumor microenvironment (TME) can easily induce tumor recurrence, metastasis, and drug resistance. The use of man-made nanozymes is considered to be an effective strategy for regulating hypoxia in the TME. Herein, Ru@MnO2 nanozymes were constructed via an in situ reduction method, and they showed excellent photothermal conversion efficiency and catalytic activity. The anti-tumor drug DOX with fluorescence was loaded on the Ru@MnO2 nanozymes, and an erythrocyte membrane was further coated on the surface of the Ru@MnO2 nanozymes to construct nanozymes with on-demand release abilities. The erythrocyte membrane (RBCm) enhances the biocompatibility of the Ru@MnO2 nanozymes and prolongs their circulation time in the blood. Ru@MnO2 nanozymes can catalyze endogenous H2O2 to produce O2 to relieve hypoxia in the TME to enhance the efficacy of the photothermal therapy/chemotherapy of cancer. In vitro studies confirmed that the Ru@MnO2 nanozymes showed good tumor penetration abilities and a synergistic anti-tumor effect. Importantly, both in vivo and in vitro studies have confirmed that the oxygen supply in situ enhanced the efficacy of the PTT/chemotherapy of cancer. Accordingly, this study demonstrated that Ru@MnO2 nanozymes can be used as an effective integrated system allowing catalysis, photothermal therapy, and chemotherapy for cancer management.

Highly Penetrable and On-Demand Oxygen Release with Tumor Activity Composite Nanosystem for Photothermal/Photodynamic Synergetic Therapy.

A deep penetrating and pH-responsive composite nanosystem was strategically developed to improve the efficacy of synergetic photothermal/photodynamic therapy (PTT/PDT) against hypoxic tumor. The designed nanosystem ([PHC]PP@HA NPs) was constructed by coloading hemoglobin (Hb) and chlorin e6 on polydopamine to build small-sized PHC NPs, which were encapsulated inside the polymer micelles (poly(ethylene glycol)-poly(ethylenimine)) and then capped with functionalized hyaluronic acid. The pH-responsive feature made [PHC]PP@HA NPs retain an initial size of ∼140 nm in blood circulation but rapidly release small PHC NPs (∼10 nm) with a high tumor-penetrating ability in the tumor microenvironment. The in vitro penetration experiment showed that the penetration depth of PHC NPs in the multicellular tumor spheroids exceeded 110 μm. The [PHC]PP@HA NPs exhibited excellent biocompatibility, deep tumor permeability, high photothermal conversion efficiency (47.09%), and low combination index (0.59) under hypoxic conditions. Notably, the nanosystem can freely adjust the release of oxygen and damaging PHC NPs in an on-demand manner on the basis of the feedback of tumor activity. This feedback tumor therapy significantly improved the synergistic effect of PTT/PDT and reduced its toxic side effects. The in vivo antitumor results showed that the tumor inhibition rate of [PHC]PP@HA NPs with an on-demand oxygen supply of Hb was ∼100%, which was much better than those of PTT alone and Hb-free nanoparticles ([PC]PP@HA NPs). Consequently, the [PHC]PP@HA NP-mediated PTT/PDT guided by feedback tumor therapy achieved an efficient tumor ablation with an extremely low tumor recurrence rate (8.3%) 60 d later, indicating the versatile potential of PTT/PDT.

Multistage-responsive clustered nanosystem to improve tumor accumulation and penetration for photothermal/enhanced radiation synergistic therapy

Developing new strategies to overcome biological barriers and achieve efficient delivery of therapeutic nanoparticles (NPs) is the key to achieve positive therapeutic outcomes in nanomedicine. Herein, a multistage-responsive clustered nanosystem is designed to systematically resolve the multiple tumor biological barriers conflict between the enhanced permeability retention (EPR) effect and spatially uniform penetration of the nanoparticles. The nanosystem with desirable diameter (initial size of ~50 nm), which is favorable for long blood circulation and high propensity of extravasation through tumor vascular interstices, can accumulate effectively around the tumor tissue through the EPR effect. Then, these pH-responsive nanoparticles are conglomerated to form large-sized aggregates (~1000 nm) in the tumor under the acidic microenvironment, and demonstrated great tumor retention. Subsequently, the photothermal treatment disperses the aggregates to be ultrasmall gold nanoclusters (~5 nm), thereby improving their tumor penetration ability, and enhancing the radiotherapeutic effect by radiosensitizer. In 4T1 tumor model, this nanosystem shows great tumor accumulation and penetration, and the tumor growth and the lung/liver metastasis in particle/PTT/RT treated mice is significantly inhibited. As a photoacoustic/fluorescence imaging agent and PT/RT synergistic agent, this pH-/laser-triggered size multistage-responsive nanosystem displayes both great tumor accumulation and penetration abilities, and shows excellent potential in tumor therapy.

Deep tumor‐penetrated nanosystem eliminates cancer stem cell for highly efficient liver cancer therapy

Cancer stem cells (CSCs), which are resistant to the traditional therapies, have been considered to account for the development, metastasis, and relapse of various malignant tumors, and therefore, must be eliminated to cure cancer. However, they can reside in deep tumor regions away from the blood vessels, and are typically inaccessible owing to the low delivery efficiency and limited tumor penetrating ability of drug carriers. To overcome these problems, we designed a tumor-penetrating peptide (tLyP-1)-conjugated ZIF-90 nanosystem loaded with doxorubicin (DOX) and N-[N-(3,5-difluorophenacetyl)-1-alanyl]-S-phenylglycine t-butyl ester (DAPT) to penetrate and eradicate differentiated cancer cells and CSCs simultaneously. The nanosystem exhibited beneficial biocompatibility, enhanced tissue penetration, high blood circulation stability, and pH-responsive drug release for favoring cancer therapy. It was found that the nanosystem could kill both cancer cells and CSCs in vitro. The in vivo results demonstrated that the ZIF-90 nanosystem can effectively accumulate in tumor tissues after long blood circulation and flexibly permeate throughout the tumor tissues. In the HCCLM3 xenograft model, the ZIF-90 nanosystem presented high-efficiency tumor suppression and drastically eradicated the CSCs in the tumor tissues with low systemic toxicity. Overall, the deep tumor-penetrating nanosystem exhibits outstanding potential for improving curative effect.

Intercellular delivery of bioorthogonal chemical receptors for enhanced tumor targeting and penetration

Targeted drug delivery using biological ligands can improve the precision of cancer therapy. However, this active targeting strategy is limited in tumor targeting and penetration abilities due to the paucity and heterogeneous distribution of targeted receptors in tumor cells, thus compromising the treatment outcomes. In this study, we developed an alternative active targeting strategy for enhanced tumor targeting and penetration through synthetic nanoparticle-mediated metabolic tumor ligand labeling for intercellular delivery of bioorthogonal chemical receptors combined with in vivo bioorthogonal click chemistry. Briefly, artificial azide-containing ligands were first labeled on perivascular tumor cells by nanoscale metabolic precursors (Az-NPs) via the enhanced permeability and retention (EPR) effect and metabolic engineering of the tumor cells. Through transport by extracellular vesicles (EVs) secreted by perivascular tumor cells, the azide-containing ligands can be autonomously transported intercellularly to adjacent cells and further spread throughout tumor tissues and label bioorthogonal ligands on cells that are not in proximity to blood vessels. Then, water-soluble dibenzocyclooctyne-modified chlorin e6 (DBCO-Ce6) was intravenously injected to react selectively, efficiently and irreversibly with the azide groups on the cell surface through an in vivo bioorthogonal click reaction. Enhanced tumor accumulation and penetration of DBCO-Ce6 was achieved through this strategy, resulting in improved therapeutic efficiency with laser irradiation for photodynamic therapy. Therefore, the artificial azide-containing ligand targeting strategy by nanoparticle-mediated metabolic labeling through the EPR effect combined with bioorthogonal click chemistry may provide an alternative strategy for enhanced tumor targeting and penetration with broad applications.

Aptamer-Pyropheophorbide a Conjugates with Tumor Spheroid Targeting and Penetration Abilities for Photodynamic Therapy.

Pyropheophorbide a (Pyro) is a widely used photosensitizer for photodynamic therapy (PDT). However, poor water solubility, aggregation-induced fluorescence quenching, and lack of selectivity to targeted cells seriously limit its application. In this work, we prepared aptamer-Pyro conjugates (APCs) by linking Pyro to hydrophilic nucleic acid aptamer to enhance its water solubility and endow it with protein tyrosine kinase 7 (PTK7) overexpressed tumor spheroid specific targeting and penetration abilities for photodynamic therapy. The molecular conjugate was successfully synthesized and dissolved well in an aqueous solution. The APCs showed strong near-infrared fluorescence in the aqueous solution and produced singlet oxygen both in the solution and cells under laser irradiation, indicating its generation of singlet oxygen during PDT was guaranteed. Owing to the cancer cell targeting ability of the aptamer, the APCs specifically bound with PTK7 overexpressed cancerous cells and showed fluorescence signal for tumor cell imaging and diagnosis. The APCs exhibited favorable enhanced phototoxicity to target tumor cells compared with control cells. More importantly, due to the small size of the molecular conjugate, the APCs efficiently penetrated into the interior of multicellular tumor spheroids (MCTS) and caused cell damage. All these results indicated that the robust aptamer-Pyro conjugate is a promising selective tumor-targeting and penetrable molecule for cancer photodynamic therapy.

Regulation of pancreatic cancer microenvironment by an intelligent gemcitabine@nanogel system via in vitro 3D model for promoting therapeutic efficiency

The passive targeting via nanomedicine to pancreatic tumor microenvironment (TME) is identified as an optimized therapeutic strategy for pancreatic ductal adenocarcinoma (PDAC) because lacking specific biomarkers and the intractable anatomical position. Herein, an in vitro 3D PDAC model was set up to evaluate the regulation of extracellular matrix (ECM) by an intelligent gemcitabine@nanogel system (GEM@NGH). This GEM@NGH system consisting of a reduction-sensitive core, the payloads of gemcitabine, and the coronal of hyaluronidase arrayed on the cationic surface was fabricated to improve intratumoral penetration and antitumor efficacy. The physicochemical properties, reduction sensitivity, cellular biocompatibility and cytotoxicity, intracellular distribution and therapeutic effects were all evaluated. Particularly, the GEM@NGH system showed excellent ECM eradication and in vitro/vivo solid tumor penetration ability as evaluated by home-built equipment and in vitro 3D PDAC model, which confirmed that GEM@NGH could be disintegrated in the tumoral reductive cytoplasm after internalization and release gemcitabine to exhibit promoted cytotoxicity. In the in vivo therapy, GEM@NGH displayed the highest tumor growth inhibition in PANC-1 tumor-bearing mice with the remarkably increased tumor penetration ability by TME regulation. The results obtained in this study indicate that specifically regulating TME by a well-designed intelligent gemcitabine@nanogel is promising way for the pancreatic cancer therapy.

A Photocaged, Water-Oxidizing, and Nucleolus-Targeted Pt(IV) Complex with a Distinct Anticancer Mechanism.

Targeted anticancer prodrugs that can be controllably activated are highly desired for personalized precision medicine in cancer therapy. Such prodrugs with unique action modes are also promising to overcome drug resistance. Herein, we report coumaplatin, an oxaliplatin-based and photocaged Pt(IV) prodrug, to realize nuclear accumulation along with "on-demand" activation. This prodrug is based on a Pt(IV) complex that can be efficiently photoactivated via water oxidation without the requirement of a reducing agent. Coumaplatin accumulates very efficiently in the nucleoli, and upon photoactivation, this prodrug exhibits a level of photocytotoxicity up to 2 orders of magnitude higher than that of oxaliplatin. Unexpectedly, this prodrug presents strikingly enhanced tumor penetration ability and utilizes a distinct action mode to overcome drug resistance; i.e., coumaplatin but not oxaliplatin induces cell senescence, p53-independent cell death, and immunogenic cell death along with T cell activation. Our findings not only provide a novel strategy for the rational design of controllably activated and nucleolus-targeted Pt(IV) anticancer prodrugs but also demonstrate that accumulating conventional platinum drugs to the nucleus is a practical way to change its canonical mechanism of action and to achieve reduced resistance.

Targeting cancer-associated fibroblasts by dual-responsive lipid-albumin nanoparticles to enhance drug perfusion for pancreatic tumor therapy

Pancreatic ductal adenocarcinoma (PDAC) is rich in cancer-associated fibroblasts (CAFs), which participate in the formation of tumor stroma. However, the dense tumor stroma of PDAC presents major barriers to drug delivery, resulting in an obstacle for PDAC therapy. Considering the special tumor microenvironment of PDAC, we constructed a novel nanoparticle which is responsive to the membrane biomarker FAP-α on CAFs and near-infrared (NIR) laser irradiation. Small sized albumin nanoparticle of paclitaxel (HSA-PTX) with strong tumor-penetration ability was encapsulated into the CAP-(a FAP-α responsive cleavable amphiphilic peptide) modified thermosensitive liposomes (CAP-TSL). Moreover, IR-780, a photothermal agent, was incorporated into CAP-TSL to afford CAP-ITSL. The designed HSA-PTX@CAP-ITSL increased the drug retention of HSA-PTX in solid tumor and HSA-PTX was released via FAP-α (specifically expresses on CAFs) triggered. Under sequential stimulation of NIR laser irradiation, IR-780 produced hyperthermia to kill tumor cells and expand the tumor interstitial space at the same time, which further promoted the release of small sized HSA-PTX in deep tumor regions. Consequently, the excellent antitumor efficacy of HSA-PTX@CAP-ITSL was demonstrated in Pan 02 subcutaneous and orthotopic tumor mouse models. Therefore, HSA-PTX@CAP-ITSL well combined chemotherapy with photothermal therapy, providing a promising drug delivery strategy for PDAC treatment.

Virus-mimicking mesoporous organosilica nanocapsules with soft framework and rough surface for enhanced cellular uptake and tumor penetration.

An enveloped virus with soft and rough shells has strong penetration ability for cells. Inspired by the unique structure of virus, we successfully constructed virus-mimicking mesoporous organosilica nanocapsules (denoted as VMONs) for the first time by decorating small-sized silica nanoparticles on soft mesoporous organosilica hollow spheres. TEM and SEM images reveal that the prepared VMONs display uniform diameters (240 nm), a soft framework, a rough surface, and excellent dispersity. Quantitative nanomechanical mapping further demonstrates that the VMONs possess an extremely low Young's modulus (36 MPa) and a scraggly surface. In view of the successful construction of the virus-mimicking nanocapsules, the VMONs are further modified with human serum albumin (HSA) and Cy5.5-maleimide (Mal-Cy5.5) to investigate their cell penetration ability. Flow cytometry analysis reveals that the internalization of VMONs@HSA-Cy5.5 increases 2.74-fold compared to that of the conventional mesoporous nanosphere. Confocal laser scanning microscopy images show that the VMONs@HSA-Cy5.5 diffuses deeper for multicellular spheroids compared to both hard and soft mesoporous organosilica nanospheres. The penetration ability of the VMONs and SMONs increases 18.49 and 6.13-fold compared to that of MONs at the depth of 60 μm. Thanks to the excellent cellular penetration ability, the virus-mimicking VMONs@HSA-Cy5.5 can effectively deliver the anticancer drug doxorubicin (Dox) into drug-resistant MCF-7/ADR human breast cancer cells and significantly enhance the chemotherapeutic efficacy. Taken together, the constructed virus-mimicking organosilica nanocapsules with a soft framework and a rough surface possess strong cellular internalization and tumor penetration abilities, providing a unique and effective nanoplatform for biomedical applications.