Treating metastatic cancer with nanotechnology

Cell membrane cloaked nanomedicines for bio-imaging and immunotherapy of cancer: Improved pharmacokinetics, cell internalization and anticancer efficacy

Despite enormous advancements in the field of oncology, the innocuous and effectual treatment of various types of malignancies remained a colossal challenge. The conventional modalities such as chemotherapy, radiotherapy, and surgery have been remained the most viable options for cancer treatment, but lacking of target-specificity, optimum safety and efficacy, and pharmacokinetic disparities are their impliable shortcomings. Though, in recent decades, numerous encroachments in the field of onco-targeted drug delivery have been adapted but several limitations (i.e., short plasma half-life, early clearance by reticuloendothelial system, immunogenicity, inadequate internalization and localization into the onco-tissues, chemoresistance, and deficient therapeutic efficacy) associated with these onco-targeted delivery systems limits their clinical viability. To abolish the aforementioned inadequacies, a promising approach has been emerged in which stealthing of synthetic nanocarriers has been attained by cloaking them into the natural cell membranes. These biomimetic nanomedicines not only retain characteristics features of the synthetic nanocarriers but also inherit the cell-membrane intrinsic functionalities. In this review, we have summarized preparation methods, mechanism of cloaking, and pharmaceutical and therapeutic superiority of cell-membrane camouflaged nanomedicines in improving the bio-imaging and immunotherapy against various types of malignancies. These pliable adaptations have revolutionized the current drug delivery strategies by optimizing the plasma circulation time, improving the permeation into the cancerous microenvironment, escaping the immune evasion and rapid clearance from the systemic circulation, minimizing the immunogenicity, and enabling the cell-cell communication via cell membrane markers of biomimetic nanomedicines. Moreover, the preeminence of cell-membrane cloaked nanomedicines in improving the bio-imaging and theranostic applications, alone or in combination with phototherapy or radiotherapy, have also been pondered.

Supramolecular nanomedicine for selective cancer therapy via sequential responsiveness to reactive oxygen species and glutathione

Cancer cells are generally immersed in an oxidative stress environment with a high intracellular reduction level. Thus, nanocarriers with sequential responsiveness to oxidative and reductive species, matching the traits of high oxidation in the tumor tissue microenvironment and high reduction potential inside cancer cells, are highly desired for specific cancer therapy. Herein, we report a supramolecular nanomedicine comprised of a reduction-responsive nanoparticle (NP) core whose surface was modified by an oxidation-responsive polyethylene glycol (PEG) derivative via strong host-guest interactions. In this delicate design, the PEGylation of NPs not only reduced their immunogenicity and extended systemic circulation, but also enabled oxidation-responsive de-PEGylation in the tumor tissues and subsequent intracellular payload release in response to glutathione (GSH) inside tumor cells. As a proof of concept, this supramolecular nanomedicine exhibited specific chemotherapeutic effects against cancer in vitro and in vivo with a decent safety profile.

Nanocarrier-based drug delivery systems for bone cancer therapy: a review

Bone cancer is a malignant tumor that originates in the bone and destroys the healthy bone tissues. Of the various types of bone tumors, osteosarcoma is the most commonly diagnosed primary bone malignancy. The standard treatment for primary malignant bone tumors comprises surgery, chemotherapy and radiotherapy. Owing to the lack of proven treatments, different forms of alternative therapeutic approaches have been examined in recent decades. Among the new therapeutic methodologies, nanotechnology-based anticancer therapy has paved the way for new targeted strategies for bone cancer treatment and bone regeneration. They include approaches such as the co-delivery of multiple drug cargoes, the enhancement of their biodistribution and transport properties, normalizing accumulation and the optimization of drug release profiles to overcome shortcomings of the existing therapy. This review examines the standard treatments for osteosarcoma, their lacunae, and the evolving therapeutic strategies based on nanocarrier-mediated combinational drug delivery systems, and future perspectives for osteosarcoma therapy.

Disrupting tumour vasculature and recruitment of aPDL1-loaded platelets control tumour metastasis

Although therapies of cancer are advancing, it remains challenging for therapeutics to reach the sites of metastasis, which accounts for majority of cancer associated death. In this study, we have developed a strategy that guides an anti-programmed cell death-ligand 1 (aPDL1) antibody to accumulate in metastatic lesions to promote anti-tumour immune responses. Briefly, we have developed a combination in which Vadimezan disrupts tumour blood vessels of tumour metastases and facilitates the recruitment and activation of adoptively transferred aPDL1-conjugated platelets. In situ activated platelets generate aPDL1-decorated platelet-derived microparticles (PMP) that diffuse within the tumour and elicit immune responses. The proposed combination increases 10-fold aPDL1 antibody accumulation in lung metastases as compared to the intravenous administration of the antibody and enhances the magnitude of immune responses leading to improved antitumour effects.

Cancer metastasis is the leading cause of death in patients, here, the authors show disrupting tumor vasculature could recruit and activate anti-PD-L1 engineered platelet at metastatic tumor sites to block the PD-1/PD-L1 crosstalk and enhance the anticancer immunotherapy.

Cancer-Cell-Derived Hybrid Vesicles from MCF-7 and HeLa Cells for Dual-Homotypic Targeting of Anticancer Drugs

Here, as a proof of concept, hybrid vesicles (VEs) are developed from two types of cancer cells, MCF-7 and HeLa, for the dual targeting of the anticancer drug doxorubicin (Dox) to cancer cells via homotypic interactions. Hybrid VEs with a size of 181.8 ± 28.2 nm and surface charge of -27.8 ± 1.9 mV are successfully prepared by the fusion of MCF-7 and HeLa VEs, as demonstrated by the fluorescence resonance energy transfer assay. The hybrid VEs exhibit enhanced intracellular uptake both in MCF-7 and HeLa cells. Dox-encapsulated hybrid VEs (Dox-hybrid VEs) also exhibit promising anticancer and antiproliferative activities against MCF-7/multidrug-resistant cells and HeLa cells. In addition, compared to free Dox, the Dox-hybrid VEs exhibit low intracellular uptake and reduced cytotoxicity for RAW264.7 cells. Thus, hybrid VEs with dual-targeting activity toward two types of cancer cells may be useful for the specific targeting of anticancer drugs for improved anticancer effects with reduced nonspecific toxicity.

Nanomaterials to Fight Cancer: An Overview on Their Multifunctional Exploitability

In recent years the worldwide research community has highlighted innumerable benefits of nanomaterials in cancer detection and therapy. Nevertheless, the development of cancer nanomedicines and other bionanotechnology requires a huge amount of considerations about the interactions of nanomaterials and biological systems, since long-term effects are not yet fully known. Open issues remain the determination of the nanoparticles distributions patterns and the internalization rate into the tumor while avoiding their accumulation in internal organs or other healthy tissues. The purpose of this work is to provide a standard overview of the most recent advances in nanomaterials to fight cancer and to collect trends and future directions to follow according to some critical aspects still present in this field. Complementary to the very recent review of Wolfram and Ferrari which discusses and classifies successful clinically-approved cancer nanodrugs as well as promising candidates in the pipeline, this work embraces part of their proposed classification system based on the exploitation of multifunctionality and extends the review to peer-reviewed journal articles published in the last 3 years identified through international databases.

Nanotechnology-Based Strategies to Evaluate and Counteract Cancer Metastasis and Neoangiogenesis

Cancer metastasis is the major cause of cancer-related morbidity and mortality. It represents one of the greatest challenges in cancer therapy, both because of the ability of metastatic cells to spread into different organs, and because of the consequent heterogeneity that characterizes primary and metastatic tumors. Nanomaterials can potentially be used as targeting or detection agents owing to unique chemical and physical features that allow tailored and tunable theranostic functions. This review highlights nanomaterial-based approaches in the detection and treatment of cancer metastasis, with a special focus on the evaluation of nanostructure effects on cell migration, invasion, and angiogenesis in the tumor microenvironment.

Systemic tumour suppression via the preferential accumulation of erythrocyte-anchored chemokine-encapsulating nanoparticles in lung metastases

Eliciting immune responses against primary tumours is hampered by their immunosuppressive microenvironment and by the greater inaccessibility of deeper intratumoural cells. However, metastatic tumour cells are exposed to highly perfused and immunoactive organs, such as the lungs. Here, by taking advantage of the preferential colocalization of intravenously administered erythrocytes with metastases in the lungs, we show that treatment with chemokine-encapsulating nanoparticles that are non-covalently anchored onto the surface of injected erythrocytes results in local and systemic tumour suppression in mouse models of lung metastasis. Such erythrocyte-anchored systemic immunotherapy led to the infiltration of effector immune cells into the lungs, in situ immunization without the need for exogenous antigens, inhibition of the progression of lung metastasis, and significantly extended animal survival and systemic immunity that suppressed the growth of distant tumours after rechallenge. Erythrocyte-mediated systemic immunotherapy may represent a general and potent strategy for cancer vaccination.

Encapsulation and pH-responsive release of bortezomib by dopamine grafted hyaluronate nanogels

Hydrophobic drugs loaded nanogels were always associated with low encapsulation efficiency and immature burst release. In this work, dopamine grafted hyaluronate nanogels were designed for bortezomib (BTZ), a hydrophobic anticancer drug and a proteasome inhibitor. It was found that there was a more efficient loading and pH-controlled release of BTZ due to the presence of dopamine groups on the skeleton of the nanogels. The drug loading content (DLC) were up to 8.58% as the nanogels modified with 29% dopamine, compared to the DLC of less than 1% for nanogels without dopamine modification. It was the pH-sensitive nature of the borated bonds between BTZ and catechol groups that endowed the pH-responsive release behavior of BTZ in vitro. In vitro study proved good biocompatibility and efficient cell uptake of the nanogels. In vivo anti-tumor experiments demonstrated that bortezomib loading into the nanogel significantly enhanced the therapeutic effect of the drug. After 14-day treatment, the average tumor volume of BTZ loaded nanogel group was reduced by 200% more than that of free BTZ group. Combined with CD44 receptor targeting ability of hyaluronate and the merits of nanogel, the catechol modified hyaluronate nanogel exhibited as an efficient chemotherapeutic formulation of BTZ for cancer treatment.

Emerging nanotaxanes for cancer therapy

The clinical application of taxane (including paclitaxel, docetaxel, and cabazitaxel)-based formulations is significantly impeded by their off-target distribution, unsatisfactory release, and acquired resistance/metastasis. Recent decades have witnessed a dramatic progress in the development of high-efficiency, low-toxicity nanotaxanes via the use of novel biomaterials and nanoparticulate drug delivery systems (nano-DDSs). Thus, in this review, the achievements of nanotaxanes-targeted delivery and stimuli-responsive nano-DDSs-in preclinical or clinical trials have been outlined. Then, emerging nanotherapeutics against tumor resistance and metastasis have been overviewed, with a particular emphasis on synergistic therapy strategies (e.g., combination with surgery, chemotherapy, radiotherapy, biotherapy, immunotherapy, gas therapy, phototherapy, and multitherapy). Finally, the latest oral nanotaxanes have been briefly discussed.

Fucoidan/chitosan nanoparticles functionalized with anti-ErbB-2 target breast cancer cells and impair tumor growth in vivo

The work herein presented reports the development of fucoidan/chitosan nanoparticles (NPs) loaded with gemcitabine and functionalized with ErbB-2 antibody at their surface (NPs + Gem + Ab). The maximum immobilization of ErbB-2 on NPs' surface was set at 10 μg mL^-1 and resulted in NPs with a size around 160 nm, a polydispersity index of 0.18, and a zeta potential of 21 mV. ErbB-2 is overexpressed in some subtypes of breast cancers, and the targeting capability of the NPs + Gem + Ab system was confirmed by an increased cellular uptake of SKBR3 cells (ErbB-2 positive) when compared to MDA-MB-231 (ErbB-2 negative). To validate the targeting efficacy of NPs + Gem + Ab, a co-culture system with human endothelial and SKBR3 cells was established. Cytotoxic effects over endothelial cells were similar for all the tested conditions (between 25 and 30%). However, the NPs + Gem + Ab system presented increased toxicity over breast cancer cells, above 80% after 24 h, when compared to free Gem and NPs + Gem (around 15% and 20%, respectively). In vivo studies demonstrated that the developed targeting system significantly reduced tumor growth and the appearance of lung metastasis compared to untreated controls. In summary, the efficacy of the NPs + Gem + Ab system to target cancer cells was established and validated both in vitro and in vivo, being a compelling alternative strategy to current chemotherapeutic approaches.

3D CoPt nanostructures hybridized with iridium complexes for multimodal imaging and combined photothermal-chemotherapy

Combined photothermal-chemotherapy has shown great potential in improving the efficiency of tumor treatment. In this article, we have designed a new type of nanocomposite Ir-CoPt-PVP composed of cobalt/platinum alloy nanoparticles (CoPt) and iridium(III) complex (Ir) for combined photothermal therapy (PTT) and chemotherapy. The obtained CoPt was synthesized by a simple solvothermal method and modified by polyvinyl pyrrolidone (PVP), which exhibited excellent photothermal efficiency and stability, and can also be a bimodal bioimaging contrast agent in photothermal imaging (PTI) and photoacoustic imaging (PAI). Furthermore, the combination therapy has shown obvious tumor cell-growth inhibition in vitro. Overall, the results revealed the great potential of Ir-CoPt-PVP nanocomposites in improving therapeutic efficiency by photothermal-chemotherapy and photothermal/photoacoustic imaging.

Synthesis of Densely Immobilized Gold-Assembled Silica Nanostructures

In this study, dense gold-assembled SiO₂ nanostructure (SiO₂@Au) was successfully developed using the Au seed-mediated growth. First, SiO₂ (150 nm) was prepared, modified by amino groups, and incubated by gold nanoparticles (ca. 3 nm Au metal nanoparticles (NPs)) to immobilize Au NPs to SiO₂ surface. Then, Au NPs were grown on the prepared SiO₂@Au seed by reducing chloroauric acid (HAuCl₄₎ by ascorbic acid (AA) in the presence of polyvinylpyrrolidone (PVP). The presence of bigger (ca. 20 nm) Au NPs on the SiO₂ surface was confirmed by transmittance electronic microscopy (TEM) images, color changes to dark blue, and UV-vis spectra broadening in the range of 450 to 750 nm. The SiO₂@Au nanostructure showed several advantages compared to the hydrofluoric acid (HF)-treated SiO₂@Au, such as easy separation, surface modification stability by 11-mercaptopundecanoic acid (R-COOH), 11-mercapto-1-undecanol (R-OH), and 1-undecanethiol (R-CH₃), and a better peroxidase-like catalysis activity for 5,5'-Tetramethylbenzidine (TMB) and hydrogen peroxide (H₂O₂) reaction. The catalytic activity of SiO₂@Au was two times better than that of HF-treated SiO₂@Au. When SiO₂@Au nanostructure was used as a surface enhanced Raman scattering (SERS) substrate, the signal of 4-aminophenol (4-ATP) on the surface of SiO₂@Au was also stronger than that of HF-treated SiO₂@Au. This study provides a potential method for nanoparticle preparation which can be replaced for Au NPs in further research and development.

Doxorubicin delivery systems based on doped CaCO3 cores and polyanion drug conjugates

In order to prolong the release and reduce the toxicity of anticancer drug - doxorubicin (DOX), delivery systems (DS) using different polyanions have been developed. Structural (size, morphological stability) and functional (encapsulation efficiency, DOX release) characteristics of three types of DS are compared: CaCO₃ porous vaterites doped with polyanions by co-precipitation and coating techniques, and DOX-polyanion conjugates. Using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), it was shown that the doping enhances the morphological stability of CaCO₃-based DS during the DOC loading. Doping of CaCO₃ cores by co-precipitation reduces its sizes (up to 1 µm) and DOX encapsulation efficiency. Polyanion-coated CaCO₃ cores and polyanion drug conjugates show about 98 w/w% DOX encapsulation. For the first time, it was shown that the release of DOX from developed DS into human blood plasma is more intense (from 1.3 to 3.0 times for different DS) than into model tumour environment.

Recent Advancements in Nanotechnology for Oral Cancer: a Review

Background:

Oral cancer is the life threatening disease causing mortality. The majority of chemotherapeutic anticancer agents are toxic to healthy tissues, have poor bioavailability and affect the quality of life of the patients.

Objective:

The main challenge in the treatment of oral cancer is the effective and safe delivery of chemotherapeutic anticancer drugs. This present review deals with the recent advancement in the nanotechnologies and its probable applications in the oral cancer treatment.

Methods:

This review includes a gist of suitable literature.

Results:

Nanotechnology brings novel methodologies or modifications in current anticancer therapies to improve individual wellbeing and survival.

Conclusion:

Nanotechnology put forward the potential of increasing the efficacy of the therapy and targeted drug delivery, which in turn increase drug absorption and bioavailability at the site of tumour. Different nanocarriers include liposomes, polymeric nanoparticles, inorganic nanoparticles, combinational (polymeric- inorganic) nanoparticles, magnetic nanoparticles, nanolipids, hydrogels, dendrimers and polymeric micelles. This review confers development of new drug delivery approaches for effective therapeutic outcomes and abating the toxicity to healthy tissues.

Harnessing nanotechnology to expand the toolbox of chemical biology

Although nanotechnology often addresses biomedical needs, nanoscale tools can also facilitate broad biological discovery. Nanoscale delivery, imaging, biosensing, and bioreactor technologies may address unmet questions at the interface between chemistry and biology. Currently, many chemical biologists do not include nanomaterials in their toolbox, and few investigators develop nanomaterials in the context of chemical tools to answer biological questions. We reason that the two fields are ripe with opportunity for greater synergy. Nanotechnologies can expand the utility of chemical tools in the hands of chemical biologists, for example, through controlled delivery of reactive and/or toxic compounds or signal-binding events of small molecules in living systems. Conversely, chemical biologists can work with nanotechnologists to address challenging biological questions that are inaccessible to both communities. This Perspective aims to introduce the chemical biology community to nanotechnologies that may expand their methodologies while inspiring nanotechnologists to address questions relevant to chemical biology.

Nanobottles for Controlled Release and Drug Delivery

Nanobottles refer to colloidal particles with a hollow interior and a single opening in the wall. These unique features make them ideal carriers for the loading, encapsulation, release, and delivery of various types of theranostic agents in an array of biomedical applications. The hollow interior gives them a high loading capacity while the opening enables quick loading and controlled release of the payload(s). More significantly, on-demand release can be readily achieved by adding a stimuli-responsive material as the inner matrix or cork stopper. This progress report begins with an introduction to the general structures and properties of nanobottles, followed by a brief discussion on the methods developed for their fabrication. The use of nanobottles for loading different types of payloads is then showcased, including small-molecule drugs, biomacromolecules, imaging contrast agents, and functional nanoparticles. The strategies explored for controlling the release by varying the size of the opening and/or integrating with a stimuli-responsive material are also highlighted. This paper concludes with some perspectives on future directions for this class of nanomaterials in terms of fabrication, functionalization, and application.

The Effect of Neddylation Blockade on Slug-Dependent Cancer Cell Migration Is Regulated by p53 Mutation Status

Simple Summary

Neddylation is a process in which the small ubiquitin-like molecule NEDD8 is covalently conjugated to target proteins by sequential enzymatic reactions. Because neddylation plays critical roles in regulating cancer growth and migration, it is emerging as an effective therapeutic target. The major tumor suppressor protein p53 reduces cancer cell migration and is inhibited by neddylation. As p53 is lost or mutated in 50% of various cancer types, this study attempted to investigate how neddylation affects cancer cell migration according to p53 status. Neddylation blockade reduced or caused no change in migration of wild type or mutant p53 cancer cell lines. In contrast, neddylation blockade induced migration of p53-null cancer cell lines. These results were mediated by the differential effect of neddylation blockade on the epithelial–mesenchymal transition activator Slug according to p53 status. Thus, the p53 status of cancer cells should be considered when developing neddylation-targeted anticancer drugs.

Abstract

The tumor suppressor protein p53 is frequently inactivated in human malignancies, in which it is associated with cancer aggressiveness and metastasis. Because p53 is heavily involved in epithelial–mesenchymal transition (EMT), a primary step in cell migration, p53 regulation is important for preventing cancer metastasis. p53 function can be modulated by diverse post-translational modifications including neddylation, a reversible process that conjugates NEDD8 to target proteins and inhibits the transcriptional activity of p53. However, the role of p53 in cancer migration by neddylation has not been fully elucidated. In this study, we reported that neddylation blockade induces cell migration depending on p53 status, specifically via the EMT-promoting transcription factor Slug. In cancer cell lines expressing wild type p53, neddylation blockade increased the transcriptional activity of p53 and expression of its downstream genes p21 and MDM2, eventually promoting proteasomal degradation of Slug. In the absence of p53, neddylation blockade increased cell migration by activating the PI3K/Akt/mTOR/Slug signaling axis. Because mutant p53 was transcriptionally inactivated but maintained the ability to bind to Slug, neddylation blockade did not affect the migration of cells expressing mutant p53. Our findings highlight how the p53 expression status influences neddylation-mediated cell migration in multiple cancer cell lines via Slug.

Rational designing of glyco-nanovehicles to target cellular heterogeneity

The aberrant expression of endocytic epidermal growth factor receptors (EGFRs) in cancer cells has emerged as a key target for therapeutic intervention. Here, we describe for the first time a state-of-the-art design for a heparan sulfate (HS) oligosaccharide-based nanovehicle to target EGFR-overexpressed cancer cells in cellular heterogeneity. An ELISA plate IC₅₀ inhibition assay and surface plasma resonance (SPR) binding assay of structurally well-defined HS oligosaccharides showed that 6-O-sulfation (6-O-S) and 6-O-phosphorylation (6-O-P) of HS tetrasaccharides significantly enhanced EGFR cognate growth factor binding. The conjugation of these HS ligands to multivalent fluorescent gold nanoparticles (AuNPs) enabled the specific and efficient targeting of EGFR-overexpressed cancer cells. In addition, this heparinoid-nanovehicle exhibited selective homing to NPs in cancer cells in three-dimensional (3D) coculture spheroids, thus providing a novel target for cancer therapy and diagnostics in the tumor microenvironment (TME).

Heparan sulfate oligosaccharide based nanovehicle greatly enhance the selective targeting of cancer cells in tumor microenvironment.

Biological Evaluation of Oil-in-Water Microemulsions as Carriers of Benzothiophene Analogues for Dermal Applications

During the last decade, many studies have been reported on the design and formulation of novel drug delivery systems proposed for dermal or transdermal administration. The efforts focus on the development of biocompatible nanodispersions that can be delivered to the skin and treat severe skin disorders, including cancer. In this context, oil-in-water (O/W) microemulsions have been developed to encapsulate and deliver lipophilic bioactive molecules for dermal application. An O/W biocompatible microemulsion composed of PBS buffer, Tween 80, and triacetin was assessed for its efficacy as a drug carrier of DPS-2, a lead compound, initially designed in-house to inhibit BRAF^V600E oncogenic kinase. The system was evaluated through both in vitro and ex vivo approaches. The cytotoxic effect, in the presence and absence of DPS-2, was examined through the thiazolyl blue tetrazolium bromide (MTT) cell proliferation assay using various cell lines. Further investigation through Western blotting revealed that cells died of necrosis. Porcine ear skin was used as a skin model to evaluate the degree of permeation of DPS-2 through skin and assess its retention. Through the ex vivo experiments, it was clarified that encapsulated DPS-2 was distributed within the full thickness of the stratum corneum (SC) and had a high affinity to hair follicles.

Recent advances in breast cancer immunotherapy: The promising impact of nanomedicines

Breast cancer (BC) is one of the prevalent cancers among women. Generally, the treatment of BC is mostly based on several prominent strategies, including chemotherapy, surgery, endocrine therapy, molecular targeted therapy, and radiation. Owing to the growing knowledge about the complexity of BC pathobiology, immunotherapy as a promising treatment modality has substantially improved the patients' care in the clinic. Immunotherapy is used to harness the patient's immune system to recognize and battle devious cancer cells. As a novel therapy approach, this emerging strategy targets the key molecular entities of tumor tissue. To achieve maximal therapeutic impacts, the dynamic interplay between cancer and immune cells needs to be fully comprehended. The key molecular machinery of solid tumors can be targeted by nanoscale immunomedicines. While discussing the potential biomarkers involved in the initiation and progression of BC, we aimed to provide comprehensive insights into the immunotherapy and articulate the recent advances in terms of the therapeutic strategies used to control this disease, including immune checkpoint inhibitors, vaccines, chimeric antigen receptor T cells therapy, and nanomedicines.

Calcium phosphate engineered photosynthetic microalgae to combat hypoxic-tumor by in-situ modulating hypoxia and cascade radio-phototherapy

Rationale: Hypoxia is one of the crucial restrictions in cancer radiotherapy (RT), which leads to the hypoxia-associated radioresistance of tumor cells and may result in the sharp decline in therapeutic efficacy. Methods: Herein, living photosynthetic microalgae (Chlorella vulgaris, C. vulgaris), were used as oxygenators, for in situ oxygen generation to relieve tumor hypoxia. We engineered the surface of C. vulgaris (CV) cells with calcium phosphate (CaP) shell by biomineralization, to form a biomimetic system (CV@CaP) for efficient tumor delivery and in-situ active photosynthetic oxygenation reaction in tumor. Results: After intravenous injection into tumor-bearing mice, CV@CaP could remarkably alleviate tumor hypoxia by continuous oxygen generation, thereby achieving enhanced radiotherapeutic effect. Furthermore, a cascade phototherapy could be fulfilled by the chlorophyll released from photosynthetic microalgae combined thermal effects under 650 nm laser irradiation. The feasibility of CV@CaP-mediated combinational treatment was finally validated in an orthotropic breast cancer mouse model, revealing its prominent anti-tumor and anti-metastasis efficacy in hypoxic-tumor management. More importantly, the engineered photosynthetic microalgae exhibited excellent fluorescence and photoacoustic imaging properties, allowing the self-monitoring of tumor therapy and tumor microenvironment. Conclusions: Our studies of this photosynthetic microsystem open up a new dimension for solving the radioresistance issue of hypoxic tumors.

Nanotechnology-Based Strategies for Berberine Delivery System in Cancer Treatment: Pulling Strings to Keep Berberine in Power

Cancer is a multifactorial disease characterized by complex molecular landscape and altered cell pathways that results in an abnormal cell growth. Natural compounds are target-specific and pose a limited cytotoxicity; therefore, can aid in the development of new therapeutic interventions for the treatment of this versatile disease. Berberine is a member of the protoberberine alkaloids family, mainly present in the root, stem, and bark of various trees, and has a reputed anticancer activity. Nonetheless, the limited bioavailability and low absorption rate are the two major hindrances following berberine administration as only 0.5% of ingested berberine absorbed in small intestine while this percentage is further decreased to 0.35%, when enter in systemic circulation. Nano-based formulation is believed to be an ideal candidate to increase absorption percentage as at nano scale level, compounds can absorb rapidly in gut. Nanotechnology-based therapeutic approaches have been implemented to overcome such problems, ultimately promoting a higher efficacy in the treatment of a plethora of diseases. This review present and critically discusses the anti-proliferative role of berberine and the nanotechnology-based therapeutic strategies used for the nano-scale delivery of berberine. Finally, the current approaches and promising perspectives of latest delivery of this alkaloid are also critically analyzed and discussed.

Organic dots (O-dots) for theranostic applications: preparation and surface engineering

Organic dots is a term used to represent materials including graphene quantum dots and carbon quantum dots because they rely on the presence of other atoms (O, H, and N) for their photoluminescence or fluorescence properties. They generally have a small size (as low as 2.5 nm), and show good photostability under prolonged irradiation. The excitation and emission wavelengths of O-dots can be tailored according to their synthetic procedure, where although their quantum yield is quite low compared with organic dyes, this is partly compensated by their large absorption coefficients. A wide range of strategies have been used to modify the surface of O-dots for passivation, improving their solubility and biocompatibility, and allowing the attachment of targeting moieties and therapeutic cargos. Hybrid nanostructures based on O-dots have been used for theranostic applications, particularly for cancer imaging and therapy. This review covers the synthesis, physics, chemistry, and characterization of O-dots. Their applications cover the prevention of protein fibril formation, and both controlled and targeted drug and gene delivery. Multifunctional therapeutic and imaging platforms have been reported, which combine four or more separate modalities, frequently including photothermal or photodynamic therapy and imaging and drug release.

Engineering Extracellular Vesicles for Cancer Therapy

Extracellular vesicles (EVs) are lipid bilayer containing nanovesicles that have a predominant role in intercellular communication and cargo delivery. EVs have recently been used as a means for drug delivery and have been depicted to elicit no or minimal immune response in vivo. The stability, biocompatibility and manipulatable tumour homing capabilities of these biological vessels make them an attractive target for the packaging and delivery of drugs and molecules to treat various diseases including cancer. The following chapter will summarise current EV engineering techniques for the purpose of delivering putative drugs and therapeutic molecules for the treatment of cancer. The relevance of EV source will be discussed, as well as the specific modifications required to manufacture them into suitable vehicles for molecular drug delivery. Furthermore, methods of EV cargo encapsulation will be evaluated with emphasis on intercellular coordination to allow for the effective emptying of therapeutic contents into target cells. While EVs possess properties making them naturally suitable nanocarriers for drugs and molecules, many challenges with clinical translation of EV-based platforms remain. These issues need to be addressed in order to harness the true potential of the EV-based therapeutic avenue.

Bioapplications of Nanomaterials

Nanobiotechnology is known as the application of nanoscaled techniques in biology which bridges natural science to living organism for improving the quality of life of humans. Nanotechnology was first issued in 1959 and has been rapidly developed, supplying numerous benefits to basic scientific academy and to clinical application including human healthcare, specifically in cancer therapy. This chapter discusses recent advances and potentials of nanotechnology in pharmaceutics, therapeutics, biosensing, bioimaging, and gene delivery that demonstrate the multifunctionality of nanotechnology.

Limiting tumor cells comprehensively at micro and macro levels to improve the therapeutic effect of chemotherapy

Clinical data shows that antitumor treatments are often ineffective if tumor cells have metastasized. To gain an effective antitumor therapeutic effect, in this report, the tumor cell was limited to the primary site and simultaneously ablated by chemotherapy. Considering the extremely complicated process of cancer metastasis, we seek to comprehensively suppress tumor metastases at both micro and macro levels, which closely link to migration and interact with each other. At the micro level, the motility of the tumor cell was decreased via accelerating mitochondria fusion. At the macro level, the unfavorable hypoxia environment was improved. A liposome-based multifunctional nanomedicine was designed by coloading latrunculin B (LAT-B), an inhibitor of actin polymerization, and doxorubicin (DOX) into the hydrophobic bilayers and aqueous cavity, respectively. Meanwhile, an oxygen reservoir named perfluoropentane (PFP) was encapsulated into the liposome core to fulfill synergistic treatment of metastatic tumors. In this paper, we demonstrated that the metastasis of the tumor cell could be effectively inhibited by LAT-B through promoting mitochondria fusion without affecting its function, making it as an encouraging candidate for effective anti-metastasis therapy. Meanwhile, we found that the combination of LAT-B and DOX shows a synergistic effect against tumors because the combined effect of these two drugs cover the entire cell proliferation process. In a word, this report presents a potential improvement in the treatment of metastatic cancer.

Multifunctional biomolecule nanostructures for cancer therapy

Biomolecule-based nanostructures are inherently multifunctional and harbour diverse biological activities, which can be explored for cancer nanomedicine. The supramolecular properties of biomolecules can be precisely programmed for the design of smart drug delivery vehicles, enabling efficient transport in vivo, targeted drug delivery and combinatorial therapy within a single design. In this Review, we discuss biomolecule-based nanostructures, including polysaccharides, nucleic acids, peptides and proteins, and highlight their enormous design space for multifunctional nanomedicines. We identify key challenges in cancer nanomedicine that can be addressed by biomolecule-based nanostructures and survey the distinct biological activities, programmability and in vivo behaviour of biomolecule-based nanostructures. Finally, we discuss challenges in the rational design, characterization and fabrication of biomolecule-based nanostructures, and identify obstacles that need to be overcome to enable clinical translation.

Polydopamine Nanoparticles Camouflaged by Stem Cell Membranes for Synergistic Chemo-Photothermal Therapy of Malignant Bone Tumors

Purpose

Nanoparticle (NP)-based chemo-photothermal therapy (CPT) has been shown to be a promising non-invasive approach for antitumor treatment. However, NPs must overcome the limitations of opsonization, clearance of the reticuloendothelial system, and ineffective targeting of tumor tissue sites. To solve these problems, stem cell membrane (SCM)-camouflaged polydopamine nanoparticles (PDA@SCM NPs) carrying the hydrophobic anticancer drug 7-ethyl-10-hydroxycamptothecin (SN38) were constructed for CPT of malignant bone tumors.

Methods

We developed umbilical-cord mesenchymal stem cell membrane-coated polydopamine nanoparticles encapsulating SN38 (PDA-SN38@SCM NPs) as an efficient tumor-targeting drug-delivery platform for CPT of malignant bone tumors. We characterized PDA@SCM NPs and evaluated the biocompatibility and anti-phagocytosis properties of PDA@SCM NPs. The antitumor activity of PDA-SN38@SCM NPs was evaluated in MG63 lines and an MG63 xenograft model in mice.

Results

Synthesized PDA-SN38@SCM NPs retained an excellent photothermal effect after SN38 loading. The drug release of PDA-SN38@SCM NPs could be triggered by near-infrared irradiation and an acidic stimulus. PDA@SCM NPs exhibited lower nonspecific macrophage uptake, longer retention in blood, and more effective accumulation at tumor sites than that shown by PDA NPs. Confocal laser scanning microscopy (CLSM) and flow cytometry showed that MG63 cells took up more PDA-SN38@SCM NPs than PDA-SN38 NPs. In vitro and in vivo antitumor studies demonstrated the outstanding performance of PDA-SN38@SCM NPs in synergistic CPT for bone tumors.

Conclusion

PDA-SN38@SCM NPs demonstrated an extraordinary synergistic CPT effect and could be a promising strategy for the treatment of malignant bone tumors.

DNA Nanostructures and DNA-Functionalized Nanoparticles for Cancer Theranostics

In the last two decades, DNA has attracted significant attention toward the development of materials at the nanoscale for emerging applications due to the unparalleled versatility and programmability of DNA building blocks. DNA-based artificial nanomaterials can be broadly classified into two categories: DNA nanostructures (DNA-NSs) and DNA-functionalized nanoparticles (DNA-NPs). More importantly, their use in nanotheranostics, a field that combines diagnostics with therapy via drug or gene delivery in an all-in-one platform, has been applied extensively in recent years to provide personalized cancer treatments. Conveniently, the ease of attachment of both imaging and therapeutic moieties to DNA-NSs or DNA-NPs enables high biostability, biocompatibility, and drug loading capabilities, and as a consequence, has markedly catalyzed the rapid growth of this field. This review aims to provide an overview of the recent progress of DNA-NSs and DNA-NPs as theranostic agents, the use of DNA-NSs and DNA-NPs as gene and drug delivery platforms, and a perspective on their clinical translation in the realm of oncology.

Manufacturing drug co-loaded liposomal formulations targeting breast cancer: Influence of preparative method on liposomes characteristics and in vitro toxicity

Developing more efficient manufacturing methods for nano therapeutic systems is becoming important, not only to better control their physico-chemical characteristics and therapeutic efficacy but also to ensure scale-up is cost-effective. The principle of cross-flow chemistry allows precise control over manufacturing parameters for the fabrication of uniform liposomal formulations, as well as providing reproducible manufacturing scale-up compared to conventional methods. We have herein investigated the use of microfluidics to produce PEGylated DSPC liposomes loaded with doxorubicin and compared their performance against identical formulations prepared by the thin-film method. The isoprenylated coumarin umbelliprenin was selected as a co-therapeutic. Umbelliprenin-loaded and doxorubicin:umbelliprenin co-loaded liposomes were fabricated using the optimised microfluidic set-up. The role of umbelliprenin as lipid bilayer fluidity modulation was characterized, and we investigated its role on liposomes size, size distribution, shape and stability compared to doxorubicin-loaded liposomes. Finally, the toxicity of all liposomal formulations was tested on a panel of human breast cancer cells (MCF-7, MDA-MB 231, BT-474) to identify the most potent formulation by liposomal fabrication method and loaded compound(s). We herein show that the microfluidic system is an alternative method to produce doxorubicin:umbelliprenin co-loaded liposomes, allowing fine control over liposome size (100-250 nm), shape, uniformity and doxorubicin drug loading (>80%). Umbelliprenin was shown to confer fluidity to model lipid biomembranes, which helps to explain the more homogeneous size and shape of co-loaded liposomes compared to liposomes without umbelliprenin. The toxicity of doxorubicin:umbelliprenin co-loaded liposomes was lower than that of free doxorubicin, due to the delayed release of doxorubicin from liposomes. An alternative, rapid and easy manufacturing method for the production of liposomes has been established using microfluidics to effectively produce uniform doxorubicin:umbelliprenin co-loaded liposomal formulations with proven cytotoxicity in human breast cancer cell lines in vitro.

Paying attention to tumor blood vessels: Cancer phototherapy assisted with nano delivery strategies

Cancer phototherapy has attracted increasing attention for its promising effectiveness and relative non-invasiveness. Over the past years, tremendous efforts have been made to develop better phototherapy strategies with various nano delivery systems. This review introduces cancer phototherapy strategies based on tumor blood vessels for improved therapeutic outcomes from the angle of direct tumor destruction and improved delivery process assisted with nano delivery designs. Latest directions and ideas of cancer phototherapy with translation potential are also discussed. Focusing on the double role of tumor vessels not only as an anti-tumor target but also as part of the delivery process, we highlight the crosstalk between photo-induced extensive effects and the complicated drug delivery process. Due to the heterogeneity of tumors, deeper investigations about the interconnection between tumor vessels and cancer phototherapy remain to be carried out. More delicate and intelligent nano delivery systems are expected to help realize the full potential of this therapeutic strategy.

Ultrasmall Fe@Fe3O4 nanoparticles as T1-T2 dual-mode MRI contrast agents for targeted tumor imaging

Targeted T₁-T₂ MRI contrast agents, which can eliminate the difficulty of image matching across multiple imaging instruments and permit specific localization of lesions, are promising candidates for more accurate diagnosis of tumors. In this study, ultrasmall Fe@Fe₃O₄ nanoparticles were designed and synthesized as T₁-T₂ dual-mode MRI contrast agents for accurate tumor imaging. First, to investigate the influence of nanoparticle size, Fe@Fe₃O₄ nanoparticles with diameters of 4, 8, and 12 nm were prepared, among which the 8 nm 3-(3,4-dihydroxyphenyl)propionic acid (DHCA)-modified nanoparticles exhibited the optimal T₁-T₂ dual-mode MRI performance. Next, to develop a tumor-targeted contrast agent, the DHCA-Fe@Fe₃O₄ nanoparticles were conjugated with the F56 peptide, which targets the vascular endothelial growth factor receptor, and the resulting F56-DHCA-Fe@Fe₃O₄ nanoparticles were found to exhibit good T₁-T₂ dual-mode imaging and tumor-targeting performance both in vitro and in vivo, indicating the nanoparticles represent a new research tool for accurate tumor diagnosis.

Nanomaterial-Based Tumor Photothermal Immunotherapy

In recent years, photothermal therapy (PTT) particularly nanomaterial-based PTT is a promising therapeutic modality and technique for cancer tumor ablation. In addition to killing tumor cells directly through heat, PTT also can induce immunogenic cell death (ICD) to activate the whole-body anti-tumor immune response, including the redistribution and activation of immune effector cells, the expression and secretion of cytokines and the transformation of memory T lymphocytes. When used in combination with immunotherapy, the efficacy of nanomaterial-based PTT can be improved. This article summarized the mechanism of nanomaterial-based PTT against cancer and how nanomaterial-based PTT impacts the tumor microenvironment and induces an immune response. Moreover, we reviewed recent advances of nanomaterial-based photothermal immunotherapy and discussed challenges and future outlook.

Long non‑coding RNA TTN‑AS1 regulates the proliferation, invasion and migration of triple‑negative breast cancer by targeting miR‑211‑5p

Increasing evidence has demonstrated that long non-coding RNAs (lncRNAs) serve important roles in numerous malignancies, including triple-negative breast cancer (TNBC). The lncRNA titin-antisense RNA1 (TTN-AS1) has previously been reported to promote tumorigenesis in various types of cancer. The present study aimed to investigate the potential role of TTN-AS1 in breast cancer and the associated underlying mechanisms. Following prediction by Starbase and confirmation by dual-luciferase reporter assay, TINCR was demonstrated to be a target gene for microRNA (miR)-211-5p. The expression levels of TTN-AS1 and miR-211-5p, which was predicted to be targeted by TTN-AS1, in TNBC tissues and in the breast cancer cell lines MDA-MB-453 and MDA-MB-231 were measured using reverse transcription-quantitative PCR. Following TTN-AS1-knockdown, cell proliferation was measured using a Cell Counting Kit-8 assay and colony formation assay, whereas cell invasion and migration were measured using Transwell and wound healing assays, respectively. Luciferase reporter assay was performed to verify the potential interaction between TTN-AS1 and miR-211-5p. In addition, rescue assays were conducted to investigate the effects of TTN-AS1 and miR-211-5p on TNBC development. The results demonstrated that TTN-AS1 expression was significantly upregulated, whereas that of miR-211-5p was found to be downregulated in TNBC tissues and cell lines compared with the matched adjacent normal tissues and normal breast epithelial cell line MCF-10A, respectively. Furthermore, TTN-AS1-knockdown inhibited the proliferation and invasive and migratory abilities of MDA-MB-453 and MDA-MB-231 cells, which was reversed following co-transfection with the miR-211-5p inhibitor. The results from luciferase reporter assay confirmed that miR-211-5p was a direct target of TTN-AS1, suggesting that TTN-AS1 may bind directly to miR-211-5p to negatively regulate its expression. In conclusion, the findings from the present study demonstrated that TTN-AS1 regulated the proliferation and invasive and migratory abilities of TNBC by targeting miR-211-5p. This study may provide some insights into the regulatory mechanism of TNBC and help the development of novel therapeutic interventions for TNBC.

Anticancer drug-loaded mesenchymal stem cells for targeted cancer therapy

Mesenchymal stem cells (MSCs) have a tumor-homing ability-they accumulate inside tumors after systemic injection, and may thus be useful as carriers for tumor-targeting therapy. To use MSCs effectively as an anti-cancer therapy, they must first be functionalized with a large amount of anti-cancer drugs without causing any significant changes to their tumor-tropism. In the present study, we attempted to modify the cell surface of MSCs with doxorubicin-loaded liposomes (DOX-Lips), using the avidin-biotin complex method, and evaluated delivery efficiency and anti-tumor efficacy of DOX-Lip-modified MSCs. The amount of DOX in DOX-Lip-modified C3H10T1/2 cells, a murine mesenchymal stem cell line, was approximately 21.5 pg per cell, with no significant changes to the tumor-tropism of C3H10T1/2 cells. Notably, DOX-Lip-modified C3H10T1/2 cells significantly suppressed the proliferation of firefly luciferase-expressing murine colon adenocarcinoma colon26/fluc cells, compared to DOX-Lips alone. Fluorescent DOX accumulated at the cell contact surface and inside green fluorescence protein-expressing colon26 (colon26/GFP) in co-cultures of DOX-Lip-modified C3H10T1/2 and colon26/GFP cells. This localized distribution was not observed when only DOX-Lips was added to colon26/GFP cells. These results suggest that DOX-Lips are efficiently delivered from DOX-Lip-modified C3H10T1/2 cells to the neighboring colon26 cells. Furthermore, DOX-Lip-modified C3H10T1/2 cells suppressed tumor growth in subcutaneous tumor-bearing mice, and in a lung metastasis mouse model. Taken together, these results indicate that the intercellular delivery of DOX may be enhanced using DOX-Lip-modified MSCs as an efficient carrier system for targeted tumor therapy.

Inhaled cytotoxic chemotherapy: clinical challenges, recent developments, and future prospects

INTRODUCTION

Since 1968, inhaled chemotherapy has been evaluated and has shown promising results up to phase II but has not yet reached the market. This is due to technological and clinical challenges that require to be overcome with the aim of optimizing the efficacy and the tolerance of drug to re-open new developments in this field. Moreover, recent changes in the therapeutic standard of care for treating the patient with lung cancer also open new opportunities to combine inhaled chemotherapy with standard treatments.

AREAS COVERED

Clinical and technological concerns are highlighted from the reported clinical trials made with inhaled cytotoxic chemotherapies. This work then focuses on new pharmaceutical developments using dry powder inhalers as inhalation devices and on formulation strategies based on controlled drug release and with sustained lung retention or based on nanomedicine. Finally, new clinical strategies are described in regard to the impact of the immunotherapy on the patient's standard of care.

EXPERT OPINION

The choice of the drug, inhalation device, and formulation strategy as well as the position of inhaled chemotherapy in the patient's clinical care are crucial factors in optimizing local tolerance and efficacy as well as in its scalability and applicability in clinical practice.

Biomedical application of chondroitin sulfate with nanoparticles in drug delivery systems: systematic review

Chondroitin sulphate captured an increasing amount of attention in the field of drug delivery systems. Nanoparticles and chondroitin sulphate were combined in different ways to form effective target nanocarriers. The study aimed to evaluate the biomedical application of chondroitin sulphate with nanoparticles in drug delivery systems. We searched PubMed, Google Scholar, and MEDLINE for studies that included data for the application of chondroitin sulphate and nanoparticles in targeting drug delivery published in English up to 25 February 2020. OHAT (Office of Health Assessment and Translation) Risk-of-Bias Tool was used to assessing the quality and risk of bias of each study. We performed a qualitative synthesis of findings from included studies. The toxicity of developed drugs has been evaluated using cell viability percentage and 50% inhibitory concentration of drugs. Twenty original articles reported the application of chondroitin sulphate on drug delivery systems were selected. Drug loading and encapsulation efficiency were from 2% to 16.1% and from 39.50% to 93.97%, respectively. The drug release was fast at start time and followed by a slow and sustain released stage. The risk of bias was rated as high in two out of twenty studies. Most of the studies presented baseline characteristics and outcomes appropriately.

In Vivo Lymphatic Circulating Tumor Cells and Progression of Metastatic Disease

Simple Summary

Deadly metastases occur when tumor cells are shed from primary tumor into lymph and blood that circulate in distinct networks of vessels and disseminate circulating tumor cells (CTCs) through the body. Therefore, detection of CTCs at potentially treatable early disease stage might improve patient survival. However, most efforts have been made to test CTCs in blood only. Here, we explored the clinically relevant photoacoustic and fluorescent flow cytometry for early in vivo detection of lymphatic CTCs using metastatic melanoma and breast cancer mouse models. We demonstrated the presence of detectable lymphatic CTCs at pre-metastatic disease, estimated correlation between CTCs, primary tumor, and metastasis, and observed parallel CTC dissemination by blood and lymph. Our findings suggest the use of lymphatic CTC testing in vivo as a new indicator of metastasis initiation, and combined assessment of two body fluids as a more promising diagnostic platform compared to existing mono-detection of blood CTCs.

Abstract

The dissemination of circulating tumor cells (CTCs) by lymph fluid is one of the key events in the development of tumor metastasis. However, little progress has been made in studying lymphatic CTCs (L-CTCs). Here, we demonstrate the detection of L-CTCs in preclinical mouse models of melanoma and breast cancer using in vivo high-sensitivity photoacoustic and fluorescent flow cytometry. We discovered that L-CTCs are be detected in pre-metastatic disease stage. The smallest primary tumor that shed L-CTCs was measured as 0.094mm×0.094mm, its volume was calculated as 0.0004 mm³; and its productivity was estimated as 1 L-CTC per 30 minutes. As the disease progressed, primary tumors continued releasing L-CTCs with certain individual dynamics. The integrated assessment of lymph and blood underlined the parallel dissemination of CTCs at all disease stages. However, the analysis of links between L-CTC counts, blood CTC (B-CTC) counts, primary tumor size and metastasis did not reveal statistically significant correlations, likely due to L-CTC heterogeneity. Altogether, our results showed the feasibility of our diagnostic platform using photoacoustic flow cytometry for preclinical L-CTC research with translational potential. Our findings also demonstrated new insights into lymphatic system involvement in CTC dissemination. They help to lay the scientific foundation for the consideration of L-CTCs as prognostic markers of metastasis and to emphasize the integrative assessment of lymph and blood.

Retooling Cancer Nanotherapeutics' Entry into Tumors to Alleviate Tumoral Hypoxia

Anti-hypoxia cancer nanomedicine (AHCN) holds exciting potential in improving oxygen-dependent therapeutic efficiencies of malignant tumors. However, most studies regarding AHCN focus on optimizing structure and function of nanomaterials with presupposed successful entry into tumor cells. From such a traditional perspective, the main barrier that AHCN needs to overcome is mainly the tumor cell membrane. However, such an oversimplified perspective would neglect that real tumors have many biological, physiological, physical, and chemical defenses preventing the current state-of-the-art AHCNs from even reaching the targeted tumor cells. Fortunately, in recent years, some studies are beginning to intentionally focus on overcoming physiological barriers to alleviate hypoxia. In this Review, the limitations behind the traditional AHCN delivery mindset are addressed and the key barriers that need to be surmounted before delivery to cancer cells and some good ways to improve cell membrane attachment, internalization, and intracellular retention are summarized. It is aimed to contribute to Review literature on this emerging topic through refreshing perspectives based on this work and what is also learnt from others. This Review would therefore assist AHCNs researchers to have a quick overview of the essential information and glean thought-provoking ideas to advance this sub-field in cancer nanomedicine.

In Vivo-assembled phthalocyanine/albumin supramolecular complexes combined with a hypoxia-activated prodrug for enhanced photodynamic immunotherapy of cancer

Immunogenic photodynamic therapy (PDT) has the potential to moderate the shortfalls of cancer immunotherapy. However, its efficacy is severely limited particularly because of the lack of optimal photosensitizers and smart delivery processes and the inherent shortcomings of PDT (e.g., hypoxia resistance). Here, we demonstrate a clinically promising approach that utilizes a water-soluble phthalocyanine derivative (PcN4) concomitantly delivered with a hypoxia-activated prodrug (AQ4N) to amplify the effect of PDT and enhance cancer immunotherapy. After intravenous injection, PcN4 selectively interacted with endogenous albumin dimers and formed supramolecular complexes, providing a facile and green approach for tumor-targeted PDT. The concomitant delivery of AQ4N overcame the limitations of hypoxia in PDT and improved the antitumor activity of PDT. Treatment with PcN4-mediated and AQ4N-amplified PDT almost completely eradicated sizable primary tumors in a triple-negative breast cancer model and significantly activated CD8⁺ T cells. As the majority of tumor infiltrating CD8⁺ T cells were both PD-1- and TIM3-positive, additional combination therapy using PD-L1/PD-1 pathway blockade was warranted. After combination with immune checkpoint blockade treatment, an enhanced abscopal effect was achieved in both distant and metastatic tumors.

Biodegradable pH-responsive amorphous calcium carbonate nanoparticles as immunoadjuvants for multimodal imaging and enhanced photoimmunotherapy

Development of bioresponsive theranostic nanoparticles to enhance cancer diagnostics and control cancer metastasis is highly desirable. In this study, we developed such a bioresponsive theranostic nanoparticle for synergistic photoimmunotherapy. In particular, these nanoparticles were constructed by embedding indocyanine green (ICG) into Mn2+-doped amorphous calcium carbonate (ACC(Mn)) nanoparticles, followed by loading of the Toll-like-receptor-7 agonist imiquimod (IMQ). The IMQ@ACC(Mn)-ICG/PEG nanoparticles respond to the acidic pH of the tumor microenvironment (TME) and co-deliver ICG and IMQ into the tumor. Selective phototherapy was achieved upon activation using a near-infrared laser. In the presence of IMQ and arising from phototherapeutically treated tumor cells, tumor-associated antigens give rise to a strong antitumor immune response. Reversal of the immunosuppressive TME via H+ scavenging of the tumor through ACC nanoparticles effectively inhibits tumor metastases. Moreover, the combination of ICG and Mn2+ also serves as an advanced contrast agent for cancer multimode imaging. Overall, these bioresponsive nanoparticles provide a promising approach for cancer theranostics with promising potential for future clinical translation.

Targeting nanoparticles for diagnosis and therapy of bone tumors: Opportunities and challenges

A variety of targeted nanoparticles were developed for the diagnosis and therapy of orthotopic and metastatic bone tumors during the past decade. This critical review will focus on principles and methods in the design of these bone-targeted nanoparticles. Ligands including bisphosphonates, aspartic acid-rich peptides and synthetic polymers were grafted on nanoparticles such as PLGA nanoparticles, liposomes, dendrimers and inorganic nanoparticles for bone targeting. Besides, other ligands such as monoclonal antibodies, peptides and aptamers targeting biomarkers on tumor/bone cells were identified for targeted diagnosis and therapy. Examples of targeted nanoparticles for the early detection of bone metastatic tumors and the ablation of cancer via chemotherapy, photothermal therapy, gene therapy and combination therapy will be intensively reviewed. The development of multifunctional nanoparticles to break down the "vicious" cycle between tumor cell proliferation and bone resorption, and the challenges and perspectives in this area will be discussed.

Treating Immunologically Cold Tumors by Precise Cancer Photoimmunotherapy with an Extendable Nanoplatform

Although immunotherapy has merged as an ideal cancer therapeutic strategy for preventing tumor growth and recurrence, effective approaches to treat immunologically cold tumors are still lacking. Herein, we reported a practical and extendable nanoplatform (HA/ZIF-8@ICG@IMQ) that facilely integrated various therapeutics and functions for boosting host antitumor immunity to treat immunologically cold tumors. The tumor-targeted and microenvironment-responsive HA/ZIF-8@ICG@IMQ facilitated the tumor-specific accumulation and release of photothermal agents and immune adjuvants. With near-infrared irradiation, the designed nanoparticles effectively enhanced the infiltration of cytotoxic T lymphocytes and helper T cells and effectively blocked the growth of primary and distant tumors. Moreover, the smart therapeutic could effectively prevent tumor rechallenge and recurrence with a long-term host immunological memory response. This method shows an effective immunologically cold tumor treatment using extendable nanotherapeutics and may have reference significance for clinical cancer therapy.

Can Bottom-Up Synthetic Biology Generate Advanced Drug-Delivery Systems?

Creating a magic bullet that can selectively kill cancer cells while sparing nearby healthy cells remains one of the most ambitious objectives in pharmacology. Nanomedicine, which relies on the use of nanotechnologies to fight disease, was envisaged to fulfill this coveted goal. Despite substantial progress, the structural complexity of therapeutic vehicles impedes their broad clinical application. Novel modular manufacturing approaches for engineering programmable drug carriers may be able to overcome some fundamental limitations of nanomedicine. We discuss how bottom-up synthetic biology principles, empowered by microfluidics, can palliate current drug carrier assembly limitations, and we demonstrate how such a magic bullet could be engineered from the bottom up to ultimately improve clinical outcomes for patients.