Breaching the Hyaluronan Barrier with PH20-Fc Facilitates Intratumoral Permeation and Enhances Antitumor Efficiency: A Comparative Investigation of Typical Therapeutic Agents in Different Nanoscales

PTN-PTPRZ1 signaling axis blocking mediates tumor microenvironment remodeling for enhanced glioblastoma treatment

Glioblastoma (GBM) is a malignant brain tumor with a poor prognosis that is highly heterogeneous and invasive. One of the most major challenges of GBM treatment in the clinic is the blood-brain barrier (BBB). Additionally, the tumor microenvironment (TME) is highly enriched with immunosuppressed M2-like tumor-associated macrophages (M2 TAMs) and glioblastoma stem cells (GSCs), which promoted the malignancy of GBM through the PTN-PTPRZ1 signaling axis. Here, we developed a self-assembled dual-targeted hybrid micelle (DT-GM1) as a nanocarrier to deliver the chemotherapeutic agent doxorubicin (DOX). We demonstrated that this DT-GM1/DOX can cross the BBB using in vitro and in vivo GBM models, and that M2pep and PTPRZ1 antibodies allow it to precisely target the tumor microenvironment where M2 TAMs and GSCs are enriched, increasing intracellular drug accumulation via multiple internalization pathways. Additionally, simultaneous elimination of M2 TAMs and GSCs blocked the PTN-PTPRZ1 signaling axis, resulting in less M2 TAM infiltration and increased polarization to the M1 phenotype, reshaping the immune microenvironment. Overall, we have established a nanocarrier that can penetrate the BBB and target the TME while also synergizing with GBM chemotherapeutic agents, providing a promising new strategy for GBM treatment.

Probiotic Spore-Based Oral Drug Delivery System for Enhancing Pancreatic Cancer Chemotherapy by Gut-Pancreas-Axis-Guided Delivery

The chemotherapeutic effectiveness of pancreatic ductal adenocarcinoma (PDAC) is severely hampered by insufficient intratumoral delivery of antitumor drugs. Here, we demonstrate that enhanced pancreatic cancer chemotherapy can be achieved by probiotic spore-based oral drug delivery system via gut-pancreas axis translocation. Clostridium butyricum spores resistant to harsh external stress are extracted as drug carriers, which are further covalently conjugated with gemcitabine-loaded mesoporous silicon nanoparticles (MGEM). The spore-based oral drug delivery system (SPORE-MGEM) migrates upstream into pancreatic tumors from the gut, which increases intratumoral drug accumulation by ∼3-fold compared with MGEM. In two orthotopic PDAC mice models, tumor growth is markedly suppressed by SPORE-MGEM without obvious side effects. Leveraging the biological contact of the gut-pancreas axis, this probiotic spore-based oral drug delivery system reveals a new avenue for enhancing PDAC chemotherapy.

Disrupting stromal barriers to enhance photothermal-chemo therapy using a halofuginone-loaded Janus mesoporous nanoplatform

Dense tumor stroma is the physiological barrier in drug delivery that prevents anticancer drugs from entering the tumor, thereby seriously limiting the drugs' therapeutic effect. In this study, a Janus nanoplatform consisting of periodic mesoporous organosilica-coated platinum nanoplatforms (JPMO-Pt) and anti-stroma drug halofuginone (HF) (denoted as JPMO-Pt-HF), was developed to deplete the tumor stroma and synergistically treat breast cancer in BALB/c mice. The prepared JPMO-Pt had a uniform size of 245 nm, a good dispersion, an excellent in vitro and in vivo biocompatibility, and a high loading capacity for HF (up to 50 μg/mg). The antitumor experiments showed that the survival rate of 4 T1 cells exhibited an obvious downward trend when the cells were incubated with the JPMO-Pt-HF and irradiated with 808 nm laser. Moreover, the cell survival rate was only about 10% at 48 h when the HF concentration was 2.0 μg/mL. Notably, JPMO-Pt-HF under irradiation had an excellent synergistic therapeutic effect on tumor cells. In vivo antitumor experiment further showed that the JPMO-Pt-HF, in combination with laser irradiation, could minimize tumor growth, showing significantly better effects than those observed for the case of monotherapy involving photothermal therapy (PTT) (152 vs. 670 mm³, p < 0.0001) and HF (152 vs. 419 mm³, p = 0.0208). In addition, immunohistochemistry of tumor tissues indicated that JPMO-Pt-HF obviously reduced the relative collagen and α-smooth muscle actin (α-SMA) area fraction. Taken together, this research designs a new platform that not only possesses the ability to degrade the tumor matrix but also combines PTT and chemotherapeutic effects, and holds promise for effective tumor treatment.

Prodrug-Based Versatile Nanomedicine with Simultaneous Physical and Physiological Tumor Penetration for Enhanced Cancer Chemo-Immunotherapy

Chemo-immunotherapy combination effect remains to be a great challenge due to the poor tumor penetration of therapeutic agents that resulted from condensed extracellular matrix (ECM), T cell-related immune escape, and thus the potential recurrence. Herein, a helix self-assembly camptothecin (CPT) prodrug with simultaneous physical and physiological tumor penetration was constructed to realize effective chemo-immunotherapy. Specifically, CPT was modified with arginine to self-assemble into nanofibers to physically improve tumor penetration. Two plasmids, pshPD-L1 and pSpam1 for expressing small hairpin RNA PD-L1 and hyaluronidase, respectively, were loaded to down-regulate tumor surface PD-L1 expression for converting anergic state of T cells into the tumor-reactive T cells and produce hyaluronidase to physiologically degrade ECM for further enhanced tumor penetration. Moreover, the degraded ECM could also increase immune cells' infiltration into tumor sites, which may exert a synergistic antitumor immunity combined with immune checkpoint inhibition. Such a nanomedicine could cause significant inhibition of primary, distant tumors, and effective prevention of tumor recurrence.

Mild Magnetic Hyperthermia-Activated Innate Immunity for Liver Cancer Therapy

Magnetic hyperthermia therapy (MHT) is noninvasive and features excellent tissue penetration for deep-seated tumors, but unfortunately, it suffers the low therapeutic efficacy due to the limited magneto-thermal efficiency and insufficient intratumor accumulation of conventional intravenous-injected magnetic nanoparticles, which are actually mostly sequestered by the mononuclear phagocyte system, especially the liver. Such a disadvantageous characteristic of preferential liver uptake is here exploited, for the first time as far as we know, to treat orthotopic liver cancer by mild MHT using specially designed composite magnetic nanoparticles. A kind of core-shell-structured and Zn²⁺-doped Zn-CoFe₂O₄@Zn-MnFe₂O₄ superparamagnetic nanoparticles (ZCMF) has been synthesized which exhibits excellent and highly controllable magnetic hyperthermia performance owing to an exchange-coupled magnetism between the core and shell, and Zn²⁺ doping. The controllable mild MHT at 43-44 °C based on ZCMF demonstrates almost complete inhibition of liver cancer cell proliferation and tumor growth, which is associated with the suppression of heat shock protein 70 (HSP70) expression. More importantly, the mild MHT-treated liver cancer cells are capable of activating natural killer (NK) cells by dramatically upregulating the expression of UL16-binding proteins (ULBPs), ligands of natural killer group 2 member D (NKG2D). As a result, the growth of both xenograft tumors and orthotopic liver tumors were almost completely suppressed under mild MHT via induced NK-cell-related antitumor immunity in vivo. This work not only evidences the great potential of mild MHT but also reveals the underlying immunity activation mechanism in liver cancer treatment by mild MHT.

Recent progress in nanomedicine for enhanced cancer chemotherapy

As one of the most important cancer treatment strategies, conventional chemotherapy has substantial side effects and leads easily to cancer treatment failure. Therefore, exploring and developing more efficient methods to enhance cancer chemotherapy is an urgently important problem that must be solved. With the development of nanotechnology, nanomedicine has showed a good application prospect in improving cancer chemotherapy. In this review, we aim to present a discussion on the significant research progress in nanomedicine for enhanced cancer chemotherapy. First, increased enrichment of drugs in tumor tissues relying on different targeting ligands and promoting tissue penetration are summarized. Second, specific subcellular organelle-targeted chemotherapy is discussed. Next, different combinational strategies to reverse multidrug resistance (MDR) and improve the effective intracellular concentration of therapeutics are discussed. Furthermore, the advantages of combination therapy for cancer treatment are emphasized. Finally, we discuss the major problems facing therapeutic nanomedicine for cancer chemotherapy, and propose possible future directions in this field.

Near-infrared light-triggered platelet arsenal for combined photothermal-immunotherapy against cancer

To address long-standing issues with tumor penetration and targeting among cancer therapeutics, we developed an anticancer platelet-based biomimetic formulation (N+R@PLTs), integrating photothermal nanoparticles (N) and immunostimulator (R) into platelets (PLTs). Exploiting the aggregative properties of platelets and high photothermal capacity, N+R@PLTs functioned as an arsenal by targeting defective tumor vascular endothelial cells, accumulating in a positive feedback aggregation cascade at sites of acute vascular damage induced by N-generated local hyperthermia, and subsequently secreting nanosized proplatelets (nPLTs) to transport active components to deep tumor tissue. The immunostimulator augmented the immunogenicity of antigens released from ablated tumors, inducing a stronger immunological response to attack residual, metastatic, and recurrent tumors. Following activation by low-power near-infrared light irradiation, the photothermal and immunological components synergistically provide exceptionally high therapeutic efficacy across nine murine models that mimicked a range of clinical requirements, and, most notably, a sophisticated model based on humanized mouse and patient-derived tumor xenograft.

Experimental and theoretical explorations of nanocarriers' multistep delivery performance for rational design and anticancer prediction

The poor understanding of the complex multistep process taken by nanocarriers during the delivery process limits the delivery efficiencies and further hinders the translation of these systems into medicine. Here, we describe a series of six self-assembled nanocarrier types with systematically altered physical properties including size, shape, and rigidity, as well as both in vitro and in vivo analyses of their performance in blood circulation, tumor penetration, cancer cell uptake, and anticancer efficacy. We also developed both data and simulation-based models for understanding the influence of physical properties, both individually and considered together, on each delivery step and overall delivery process. Thus, beyond finding that nanocarriers that are simultaneously endowed with tubular shape, short length, and low rigidity outperformed the other types, we now have a suit of theoretical models that can predict how nanocarrier properties will individually and collectively perform in the multistep delivery of anticancer therapies.

Biodegradable Nanocomposite with Dual Cell-Tissue Penetration for Deep Tumor Chemo-Phototherapy

Chemo-phototherapy, as a promising cancer combination therapy strategy, has attracted widespread attention. However, the complex tumor microenvironment restricts the penetration depth of chemo-phototherapy agents in the tumor region. Here, biodegradable amphiphilic gelatin (AG) wrapped nanocomposite (PRDCuS@AG) composed of doxorubicin and copper sulfide (CuS)-loaded dendrimer is designed for deep tumor chemo-phototherapy. PR in PRDCuS@AG represents arginine-conjugated polyamidoamine dendrimer. PRDCuS@AG can rapidly biodegrade into PRDCuS by matrix metalloproteinases under near-infrared light irradiation. The resulted PRDCuS harbors dual cell-tissue penetration ability, which can effectively penetrate deep into the tumor tissue. In particular, PRDCuS@AG achieves photoacoustic imaging-guided synergistic chemo-phototherapy with 97% of tumor inhibition rate. Moreover, PRDCuS@AG can further degrade into 3 nm ultrasmall CuS, which can be eliminated from the body after treatment to avoid side effects. This strategy provides an insight that the development of chemo-phototherapy agents with high penetration ability to overcome the limitation of current deep tumor therapy.

A Size-Changeable Collagenase-Modified Nanoscavenger for Increasing Penetration and Retention of Nanomedicine in Deep Tumor Tissue

The complex tumor microenvironment constitutes a variety of barriers to prevent nanoparticles (NPs) delivery and results in extremely low accumulation of nanomedicines in solid tumors. Here, a newly developed size-changeable collagenase-modified polymer micelle is employed to enhance the penetration and retention of nanomedicine in deep tumor tissue. The TCPPB micelle is first formed by self-assembly of maleimide-terminated poly(ethylene glycol)-block-poly(β-amino ester) (MAL-PEG-PBAE) and succinic anhydride-modified cisplatin-conjugated poly(ε-caprolactone)-block-poly(ethylene oxide)-triphenylphosphonium (CDDP-PCL-PEO-TPP). Next, Col-TCPPB NPs are prepared through a "click" chemical combination of thiolated collagenase and maleimide groups on TCPPB micelle. Finally, biocompatible chondroitin sulfate (CS) is coated to obtain CS/Col-TCPPB NPs for avoiding collagenase inactivation in blood circulation. In tumor acidic microenvironment, the hydrophobic PBAE segments of the resultant micelles become hydrophilic, leading to a dissociation and subsequent dissolution of partial collagenase-containing components (Col-PEG-PBAE) from NPs. The dissolved Col-PEG-PBAE promotes the digestion of collagen fibers in tumor tissue like a scavenger, which enhances the NPs penetration. Simultaneously, the increased hydrophilicity of residual Col-PEG-PBAE in the micellar matrix causes an expansion of the NPs, resulting in an enhanced intratumoral retention. In tumor cells, the NPs target to release the cisplatin drugs into mitochondria, achieving an excellent anticancer efficacy.

A Sequential Target-Responsive Nanocarrier with Enhanced Tumor Penetration and Neighboring Effect In Vivo

Nanodrug-based cancer therapy is impeded by poor penetration into deep tumor tissues mainly due to the overexpression of hyaluronic acid (HA) in the tumor extracellular matrix (ECM). Although modification of nanoparticles (NPs) with hyaluronidase (HAase) is a potent strategy, it remains challenging to get a uniform distribution of drug at the tumor site because of the internalization of NPs by the cells in the tumor and HA regeneration. Herein, an intelligent nanocarrier, which can release HAase in response to the acidic tumor microenvironment (pH 6.5) and perform a strong neighboring effect with size reduction to overcome the above two problems and accomplish drug deep tumor penetration in vivo, is reported. In this design, HAase is encapsulated on the surfaces of doxorubicin (DOX) preloaded ZnO-DOX NPs using a charge convertible polymer PEG-PAH-DMMA (ZDHD). The polymer can release HAase to degrade HA in the tumor ECM (pH 6.5). ZnO-DOX NPs can release DOX in lysosomes (pH 4.5) to induce cell apoptosis, and exert a neighboring effect with size reduction to infect neighboring cells. The hierarchical targeted release of HAase and drugs is demonstrated to enhance tumor penetration and decrease side effects in vivo. This work shows promise for further application of ZDHD NPs in cancer therapy.

Synergistically enhanced anticancer effect of codelivered curcumin and siPlk1 by stimuli-responsive α-lactalbumin nanospheres

AIM

To achieve enhanced anticancer efficacy by combined siPlk1 and curcumin (cur) therapy using α-lactalbumin (α-lac) nanocarrier delivery.

MATERIALS & METHODS

α-Lac was partially hydrolyzed into amphiphilic peptides, and then self-assembled into nanospheres (NS). Cur was loaded into their hydrophobic core during the self-assembly process. siPlk1-SH was cross-linked with the endogenous cysteines on the NS. CRGDK peptide was conjugated on NS to target integrins overexpressed in HeLa cells.

RESULTS & CONCLUSION

The Cur and siPlk1 coloaded NS formulations possessed an enhanced tumor targeting and antitumor properties. Drugs were responsively released from disulfide bonds cross-linked RGD-NS/Cur/siPlk1 corresponding to the high intracellular glutathione concentrations of cancer cells. Both in vitro cell viability experiments and in vivo antitumor evaluations demonstrated that the codelivered nanosphere platform exhibited excellent tumor targeting and synergistic antitumor efficacy.

A mitochondria-targeted delivery system of doxorubicin and evodiamine for the treatment of metastatic breast cancer

For mitochondria-targeted nano-drug delivery systems against cancer, effectively targeting and releasing the drug into mitochondria are the keys to improve the therapeutic effect. In this study, mitochondria-targeted and reduction-sensitive micelles were developed to co-deliver doxorubicin (DOX) and evodiamine (EVO) for the treatment of metastatic breast cancer. After entering cancer cells, the micelles first targeted mitochondria through triphenylphosphonium cations. Then, the disulfide bonds of the micelles were cleaved by GSH, and both DOX and EVO were released near the mitochondria. The released EVO subsequently destroyed the mitochondrial membrane, resulting in a large amount of DOX entering the mitochondria and improving the anti-tumor effect of DOX. These mitochondria-targeted and reduction-sensitive micelles loaded with doxorubicin and evodiamine showed significant inhibition of the tumor cell growth both in vitro and in vivo.

For mitochondria-targeted nano-drug delivery systems against cancer, effectively targeting and releasing the drug into mitochondria are the keys to improve the therapeutic effect.

Highly enhanced cancer immunotherapy by combining nanovaccine with hyaluronidase

Tumor vaccine has been one of the research hotspots for cancer immunotherapy in recent years. By introducing tumor antigens into the body, the patient's own immune system will be specifically activated to induce effective immune responses for controlling or eliminating the malignant tumor cells. In this study, a simple nanovaccine was developed to induce antigen-specific anti-tumor immune responses. Polycationic polyethylenimine (PEI) was utilized to co-deliver the antigen ovalbumin (OVA) and the adjuvant unmethylated cytosine-phosphate-guanine (CpG) by electrostatic binding. The positively charged PEI could be beneficial to augment the PEI/CpG/OVA nanovaccine uptake in dendritic cells (DCs) and facilitate the endosomal escape of the nanovaccine for antigen delivering into the cytoplasm. The nanovaccine showed significant stimulation on DCs' maturation in vitro, and it was further applied for in vivo anti-tumor immunotherapy. To enhance the tumor infiltration of the nanovaccine-generated tumor-specific T cells, hyaluronidase (HAase) was employed to increase the permeability of the tumor tissues by breaking down the hyaluronan (HA) in the extracellular matrix (ECM) of tumors. Highly enhanced in vivo anti-tumor therapeutic efficiency was achieved by combining the PEI/CpG/OVA nanovaccine with HAase, which was attributed to the increased quantity of OVA-specific T cells in tumor tissues. The combination of nanovaccine with HAase has offered a simple and efficient strategy for inducing powerful anti-tumor effect in cancer immunotherapy.