PEG-functionalized iron oxide nanoclusters loaded with chlorin e6 for targeted, NIR light induced, photodynamic therapy

Polyhedral magnetic nanoparticles induce apoptosis in gastric cancer stem cells and suppressing tumor growth through magnetic force generation

Gastric cancer is a prevalent malignant tumor worldwide, posing challenges due to its poor prognosis and limited treatment options. Cancer stem cells (CSCs) were demonstrated as a subset of cancer cells responsible for tumor initiation and progression, and their inherent resistance to conventional chemotherapy and radiotherapy critically contributes to tumor recurrence and metastasis. Promoting the eradication of cancer stem cells is crucial for enhancing the efficacy of cancer treatments. This study introduces a novel therapeutic strategy utilizing polyhedral magnetic nanoparticles (PMNPs) functionalized with CD44 antibodies and cell-penetrating peptides (CPPs) to improve uptake by gastric cancer stem cells (MCSCs). PMNPs, synthesized via thermal decomposition, exhibited a diameter of 90 nm ± 9 nm and a saturation magnetization of 79.9 emu/g. Functionalization enhanced their uptake capabilities. Under a rotating magnetic field (RMF) of 15 Hz, PMNPs disrupted cellular structure, leading to apoptosis and ferroptosis in MCSCs. The in vitro studies showed significant reduction in MCSCs viability, while in vivo studies demonstrated tumor growth suppression with minimal side effects and high biocompatibility. This work presents a novel strategy for designing magnetic nanoparticles to mechanically destroy cancer stem cells, offering a more efficient and safety treatment option for gastric cancer.

Strategies for the development of metalloimmunotherapies

Metal ions play crucial roles in the regulation of immune pathways. In fact, metallodrugs have a long record of accomplishment as effective treatments for a wide range of diseases. Here we argue that the modulation of interactions of metal ions with molecules and cells involved in the immune system forms the basis of a new class of immunotherapies. By examining how metal ions modulate the innate and adaptive immune systems, as well as host-microbiota interactions, we discuss strategies for the development of such metalloimmunotherapies for the treatment of cancer and other immune-related diseases.

A review of recent advances in the use of complex metal nanostructures for biomedical applications from diagnosis to treatment

Complex metal nanostructures represent an exceptional category of materials characterized by distinct morphologies and physicochemical properties. Nanostructures with shape anisotropies, such as nanorods, nanostars, nanocages, and nanoprisms, are particularly appealing due to their tunable surface plasmon resonances, controllable surface chemistries, and effective targeting capabilities. These complex nanostructures can absorb light in the near-infrared, enabling noteworthy applications in nanomedicine, molecular imaging, and biology. The engineering of targeting abilities through surface modifications involving ligands, antibodies, peptides, and other agents potentiates their effects. Recent years have witnessed the development of innovative structures with diverse compositions, expanding their applications in biomedicine. These applications encompass targeted imaging, surface-enhanced Raman spectroscopy, near-infrared II imaging, catalytic therapy, photothermal therapy, and cancer treatment. This review seeks to provide the nanomedicine community with a thorough and informative overview of the evolving landscape of complex metal nanoparticle research, with a specific emphasis on their roles in imaging, cancer therapy, infectious diseases, and biofilm treatment. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Diagnostic Tools > Diagnostic Nanodevices.

Research Progress of Natural Product Photosensitizers in Photodynamic Therapy

Photodynamic therapy is a noninvasive cancer treatment that utilizes photosensitizers to generate reactive oxygen species upon light exposure, leading to tumor cell apoptosis. Although photosensitizers have shown efficacy in clinical practice, they are associated with certain disadvantages, such as a certain degree of toxicity and limited availability. Recent studies have shown that natural product photosensitizers offer promising options due to their low toxicity and potential therapeutic effects. In this review, we provide a summary and evaluation of the current clinical photosensitizers that are commonly used and delve into the anticancer potential of natural product photosensitizers like psoralens, quinonoids, chlorophyll derivatives, curcumin, chrysophanol, doxorubicin, tetracyclines, Leguminosae extracts, and Lonicera japonica extract. The emphasis is on their phototoxicity, pharmacological benefits, and effectiveness against different types of diseases. Novel and more effective natural product photosensitizers for future clinical application are yet to be explored in further research. In conclusion, natural product photosensitizers have potential in photodynamic therapy and represent a promising area of research for cancer treatment.

Phototoxicity in vitro and safety in vivo of the emulsion photosensitizer based on furanocoumarins of Heracleum sosnowskyi

The use of plants such as giant hogweed as raw materials for the manufacture of dosage forms has been little explored. In this study, we utilized furanocoumarins from the Heracleum sosnowskyi plant to create an experimental emulsion dosage form (EmFHS). The EmFHS was finely dispersed (481.8 nm ± 71.1 nm), shelf-stable, and contained predominantly 8-methoxypsoralen at a concentration of 1 mg/ml. Phototoxicity analysis of EmFHS for THP-1 cells under UV (365 nm) irradiation showed an IC50 of 19.1 µg/ml (24 h) and 6.3 µg/ml (48 h). In relation to spheroids (L929), EmFHS exhibited a phototoxic effect in the concentration range of 31.25-125 µg/ml8-MOP. A full phototoxic effect was observed 48 h after UV irradiation. The phototoxic effect of EmFHS in vitro was dose-dependent and comparable to the effect of emulsion synthetic 8-methoxypsoralen and chlorin e6 solution. EmFHS cytotoxicity was caused solely by UV radiation, and toxicity in the dark was minimal. EmFHS, administered at a dose of 3 mg/kg8-MOP, was found to be safe after a single intravenous administration to rats. It had a photosensitizing effect in the form of local photodermatitis when exposed to UV irradiation at a dose of 44 J/cm2. The biokinetics of emulsion furanocoumarins showed that the phototoxic effect of EmFHS is due to the high penetration ability of the emulsion into cells of spheroids. At the same time, it has a low degree of cumulation when administered intravenously. The obtained data suggest that EmFHS may be a promising treatment for PUVA therapy of various dermatological diseases. Additionally, the plant Heracleum sosnowskyi shows potential as a basis for creating new dosage forms with phototherapeutic effects.

Tailoring the surface charges of iron-crosslinked dextran nanogels towards improved tumor-associated macrophage targeting

Tumor-associated macrophages (TAMs) have emerged as therapeutic interests in cancer nanomedicine because TAMs play a pivotal role in the immune microenvironment of solid tumors. Dextran and its derived nanocarriers are among the most promising nanomaterials for TAM targeting due to their intrinsic affinities towards macrophages. Various dextran-based nanomaterials have been developed to image TAMs. However, the effects of physiochemical properties especially for surface charges of dextran nanomaterials on TAM-targeting efficacy were ambiguous in literature. To figure out the surface charge effects on TAM targeting, here we developed a facile non-covalent self-assembly strategy to construct oppositely charged dextran nanogels (NGs) utilizing the coordination interaction of ferric ions, chlorine e6 (Ce6) dye and three dextran derivatives, diethylaminoethyl-, sulfate sodium- and carboxymethyl-dextran. The acquired dextran NGs exhibit different charges but similar hydrodynamic size, Ce6 loading and mechanical stiffness, which enables a side-by-side comparison of the effects of NG surface charges on TAM targeting monitored by the Ce6 fluorescence imaging. Compared with negative NGs, the positive NG clearly displays a superior TAM targeting in murine breast cancer model. This study identifies that positively charged dextran NG could be a promising approach to better engineer nanomedicine towards an improved TAM targeting.

An engineered lymph node comprising porous collagen scaffold with hybridized biological signals embedded in B cell membrane coatings

Complications can arise from damaging or removing lymph nodes after surgeries for malignant tumours. Our team has developed an innovative solution to recreate lymph nodes via an engineering approach. Using a Type II collagen scaffold coated with B cell membranes for the sake of attracting T cells in different regions, we could mimic the thymus-dependent and thymus-independent areas in vitro. This engineering strategy based on biophysical mimicry has a great potential for clinical applications. By further conjugating biological signals, anti-CD3/28, onto the scaffold coated with the B cell membrane, we achieved an 11.6-fold expansion of T cells within 14 days of in vitro culture while ensuring their activity, phenotype homeostasis, and differentiation capacity kept intact. Artificial lymph nodes had excellent biocompatibility and caused no pathological or physiological adverse effects after implantation into C57BL6 mice. In vivo assays also demonstrated that this artificial lymph node system positively adhered to omental tissues, creating an environment that fostered T cell growth and prevented cellular failure and death. Additionally, it induced vascular and lymphatic vessel invasion, which was beneficial to the migration and circulation of T cells between this system and peripheral blood. Due to the porous collagen fibre structure, it also facilitated the infiltration of host immune cells. This work opens new avenues to immune organ regeneration via a tissue engineering approach.

Recent Advances in Nanobiotechnology for the Treatment of Non-Hodgkin's Lymphoma

Lymphoma is the eighth most common type of cancer worldwide. Currently, lymphoma is mainly classified into two main groups: Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL), with NHL accounting for 80% to 90% of the cases. NHL is primarily divided into B, T, and natural killer (NK) cell lymphoma. Nanotechnology is developing rapidly and has made significant contributions to the field of medicine. This review summarizes the advancements of nanobiotechnology in recent years and its applications in the treatment of NHL, especially in diffuse large B cell lymphoma (DLBCL), primary central nervous system lymphoma (PCNSL), and follicular lymphoma (FL). The technologies discussed include clinical imaging, targeted drug delivery, photodynamic therapy (PDT), and thermodynamic therapy (TDT) for lymphoma. This review aims to provide a better understanding of the use of nanotechnology in the treatment of non-Hodgkin's lymphoma.

Towards the Clinical Translation of a Silver Sulfide Nanoparticle Contrast Agent: Large Scale Production with a Highly Parallelized Microfluidic Chip

Ultrasmall silver sulfide nanoparticles (Ag 2 S-NP) have been identified as promising contrast agents for a number of modalities and in particular for dual-energy mammography. These Ag 2 S-NP have demonstrated marked advantages over clinically available agents with the ability to generate higher contrast with high biocompatibility. However, current synthesis methods are low-throughput and highly time-intensive, limiting the possibility of large animal studies or eventual clinical use of this potential imaging agent. We herein report the use of a scalable silicon microfluidic system (SSMS) for the large-scale synthesis of Ag 2 S-NP. Using SSMS chips with 1 channel, 10 parallelized channels, and 256 parallelized channels, we determined that the Ag 2 S-NP produced were of similar quality as measured by core size, concentration, UV-visible spectrometry, and in vitro contrast generation. Moreover, by combining parallelized chips with increasing reagent concentration, we were able to increase output by an overall factor of 3,400. We also found that in vivo imaging contrast generation was consistent across synthesis methods and confirmed renal clearance of the ultrasmall nanoparticles. Finally, we found best-in-class clearance of the Ag 2 S-NP occurred within 24 hours. These studies have identified a promising method for the large-scale production of Ag 2 S-NP, paving the way for eventual clinical translation.

A Supramolecular Assembly Strategy for Hydrophilic Drug Delivery towards Synergistic Cancer Treatment

To improve the drug loading, tumor targeting, and delivery simplicity of hydrophilic drugs, we propose a supramolecular assembly strategy that potentially benefits a wide range of hydrophilic drug delivery. Firstly, we choose a hydrophilic drug (tirapazamine) as a model drug to directly co-assemble with chlorin e6 (Ce6) at different molar ratios, and systematically evaluate the resultant Ce6-tirapazamine nanoparticles (CT NPs) in aspects of size distribution, polydispersity, morphology, optical properties and molecular dynamics simulation. Based on the assembling facts between Ce6 and tirapazamine, we summarize a plausible rule of the supramolecular assembly for hydrophilic drugs. To validate our findings, more drugs with increasing hydrophilicity, such as temozolomide, gemcitabine hydrochloride and 5-azacytidine, successfully co-assemble with Ce6 into nanostructures by following similar assembling behaviors, demonstrating that our assembling rule may guide a wide range of hydrophilic drug delivery. Next, the combination of Ce6 and tirapazamine was chosen as the representative to investigate the anti-tumor activities of the supramolecular assemblies. CT NPs showed synergistic anti-tumor efficacy, increased tumor accumulation and significant tumor progression and metastasis inhibition in tumor-bearing mice. We anticipate that the supramolecular assembly mechanism will provide broad guidance for developing easy-to-make but functional nanomedicines. STATEMENT OF SIGNIFICANCE: Although thousands of nanomedicines have been developed, only a few have been approved for clinical use. The manufacturing complexity significantly hinders the "bench-to-bed" translation of nanomedicines. Hence, we need to rethink how to conduct research on translational nanomedicines by avoiding more and more complex chemistry and complicated nanostructures. Here, we summarize a plausible rule according to multiple supramolecular assembly pairs and propose a supramolecular assembly strategy that can improve the drug loading, tumor targeting, and manufacturing simplicity of nanomedicine for hydrophilic drugs. The supramolecular assembly strategy would guide a broader range of drug delivery to provide a new paradigm for developing easy-to-make but multifunctional nanoformulations for synergistic cancer treatment.

Smart Nanostructured Materials for SARS-CoV-2 and Variants Prevention, Biosensing and Vaccination

The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has raised great concerns about human health globally. At the current stage, prevention and vaccination are still the most efficient ways to slow down the pandemic and to treat SARS-CoV-2 in various aspects. In this review, we summarize current progress and research activities in developing smart nanostructured materials for COVID-19 prevention, sensing, and vaccination. A few established concepts to prevent the spreading of SARS-CoV-2 and the variants of concerns (VOCs) are firstly reviewed, which emphasizes the importance of smart nanostructures in cutting the virus spreading chains. In the second part, we focus our discussion on the development of stimuli-responsive nanostructures for high-performance biosensing and detection of SARS-CoV-2 and VOCs. The use of nanostructures in developing effective and reliable vaccines for SARS-CoV-2 and VOCs will be introduced in the following section. In the conclusion, we summarize the current research focus on smart nanostructured materials for SARS-CoV-2 treatment. Some existing challenges are also provided, which need continuous efforts in creating smart nanostructured materials for coronavirus biosensing, treatment, and vaccination.

Chemical Modulation of Glucose Metabolism with a Fluorinated CaCO3 Nanoregulator Can Potentiate Radiotherapy by Programming Antitumor Immunity

Tumor hypoxia and acidity are well-known features in solid tumors that cause immunosuppression and therapeutic resistance. Herein, we rationally synthesized a multifunctional fluorinated calcium carbonate (fCaCO₃) nanoregulator by coating CaCO₃ nanoparticles with dopamine-grafted perfluorosebacic acid (DA₂-PFSEA) and ferric ions by utilizing their coordination interaction. After PEGylation, the obtained fCaCO₃-PEG showed high loading efficacy to perfluoro-15-crown-5-ether (PFCE), a type of perfluorocarbon with high oxygen solubility, thereby working as both oxygen nanoshuttles and proton sponges to reverse tumor hypoxia and acidity-induced resistance to radiotherapy. The as-prepared PFCE@fCaCO₃-PEG could not only function as long-circulating oxygen nanoshuttles to attenuate tumor hypoxia but also neutralize the acidic tumor microenvironment by restricting the production of lactic acid and reacting with extracellular protons. As a result, treatment with PFCE@fCaCO₃-PEG could improve the therapeutic outcome of radiotherapy toward two murine tumors with distinct immunogenicity. The PFCE@fCaCO₃-PEG-assisted radiotherapy could also collectively inhibit the growth of unirradiated tumors and reject rechallenged tumors by synergistically eliciting protective antitumor immunity. Therefore, our work presents the preparation of fluorinated CaCO₃ nanoregulators to reverse tumor immunosuppression and potentiate radiotherapy through chemically modulating tumor hypoxic and acidic microenvironments tightly associated with tumor glucose metabolism.

Iron oxide nanoparticle targeting mechanism and its application in tumor magnetic resonance imaging and therapy

Iron oxide nanoparticles (IONPs) can be applied to targeted drug delivery, targeted diagnosis and treatment of tumors due to their easy preparation, good biocompatibility, low biotoxicity, high imaging quality, high magnetothermal sensitivity and stable targeting after certain surface modifications. However, the complexity of the mechanism of action and their properties has led to there being few clinical applications of IONPs. This review first describes the targeting mechanisms of IONPs and their toxicity issues, then discusses the applications of IONP targeting studies in tumor MRI. Finally, the applications of IONP targeting in tumor therapy are listed. The authors show the advantages of targeting IONPs and hope that the review will increase the possibility of converting IONPs from biomedical applications to clinical applications.

Magnetic Field-Modulated Plasmonic Scattering of Hybrid Nanorods for FFT-Weighted OCT Imaging in NIR-II

We report a method for fast Fourier transform (FFT)-weighted optical coherence tomography (OCT) in the second biological tissue transparency window by actively modulating the plasmonic scattering of Fe₃O₄@Au hybrid nanorods using magnetic fields. Instead of tracking the nanoparticles' lateral displacement in conventional magnetomotive OCT imaging, we monitor the nanorod rotation and optical signal changes under an alternating magnetic field in real time. The coherent rotation of the nanorods with the field produces periodic OCT signals, and the FFT is then used to convert the periodic OCT signals in the time domain to a single peak in the frequency domain. This allows automatic screening of nanorod signals from the random biological noises and reconstruction of FFT-weighted images using a computer program based on a time-sequence image set. Compared with conventional magnetomotive OCT, the FFT-weighted imaging technique creates enhanced OCT images with dB-scale contrast over an order of magnitude higher than the original images.

Hyaluronic Acid–Stabilized Fe3O4 Nanoparticles for Promoting In Vivo Magnetic Resonance Imaging of Tumors

The use of iron oxide (Fe3O4) nanoparticles as novel contrast agents for magnetic resonance imaging (MRI) has attracted great interest due to their high r2 relaxivity. However, both poor colloidal stability and lack of effective targeting ability have impeded their further expansion in the clinics. Here, we reported the creation of hyaluronic acid (HA)-stabilized Fe3O4 nanoparticles prepared by a hydrothermal co-precipitation method and followed by electrostatic adsorption of HA onto the nanoparticle surface. The water-soluble HA functions not only as a stabilizer but also as a targeting ligand with high affinity for the CD44 receptor overexpressed in many tumors. The resulting HA-stabilized Fe3O4 nanoparticles have an estimated size of sub-20 nm as observed by transmission electron microscopy (TEM) imaging and exhibited long-term colloidal stability in aqueous solution. We found that the nanoparticles are hemocompatible and cytocompatible under certain concentrations. As verified by quantifying the cellular uptake, the Fe3O4@HA nanoparticles were able to target a model cell line (HeLa cells) overexpressing the CD44 receptor through an active pathway. In addition, we showed that the nanoparticles can be used as effective contrast agents for MRI both in vitro in HeLa cells and in vivo in a xenografted HeLa tumor model in rodents. We believe that our findings shed important light on the use of active targeting ligands to improve the contrast of lesion for tumor-specific MRI in the nano-based diagnosis systems.

New Generation of Photosensitizers Based on Inorganic Nanomaterials

Advance of nanomaterials and nanotechnology has offered new possibilities for photodynamic therapy (PDT). Large amount of different kinds of sensitizers and targeting moieties can now be loaded in nanometer's volume, which not only results in the improvement of the efficacy of PDT, but also enables the control of image-guided PDT with unprecedented precision and variation. This chapter shall overview the recently most studied inorganic nanomaterials for PDT.

Recent Development of MOF-Based Photothermal Agent for Tumor Ablation

Metal-organic frameworks (MOFs) are 3D-architecture compounds of metal ions and organic molecules with sufficient and permanent porosity, showing great potential as a versatile platform to load various functional moieties to endow the hybrid materials with specific applications. Currently, a variety of photothermal nanometals have been embedded into organic ligands for integrating the unique photothermal effects with the merits of MOFs to improve their performances for cancer therapy. In this review, we have summarized a series of novel MOF-based photothermal materials for this unique therapeutic modality against tumors from three main aspects according to their chemical compositions and structures, i) metal-doped MOF, ii) organic-doped MOF, and iii) polymer-coated MOF. In addition, we have summarized the latest developments and characteristics of MOF-based photothermal agents, such as good biocompatibility, low toxicity, and responsive photothermal conversion without destroying the structure of hybrid photothermal agent. At last, we addressed the future perspectives of MOF-based photothermal agent in the field of phototherapy.

Evaluation of photocytotoxicity liposomal form of furanocoumarins Sosnowsky's hogweed

Sosnovsky's hogweed, Heracleum sosnowskyi has a high photosensitizing ability. Although Sosnovsky's hogweed is known as a poisonous plant, its chemical composition and phototoxicity are poorly studied. We analyzed the chemical composition of the Sosnovsky's hogweed juice that grew in natural conditions. It was found that the content of 8-methoxypsoralen in the juice is 1332.7 mg/L, and that of 5-methoxypsoralen is 34.2 mg/L. We have developed and analyzed liposomes containing furanocoumarins of Sosnovsky's hogweed juice and studied their photocytotoxicity in L929 mouse fibroblast cell culture. It was found that liposomes containing furanocoumarins of Sosnovsky's hogweed juice are more toxic for L929 cells in comparison with liposomal forms of pure substances 8-methoxypsoralen and 5-methoxypsoralen. It was found that when exposed to UV radiation at 365 nm at a dose of 22.2 J/cm², the liposomal form of furanocoumarins Sosnovsky's hogweed is 3 times more toxic to L929 cells than in the dark. It was found that the photocytotoxic effect of liposomal furanocoumarins Sosnovsky's hogweed is a strongly stimulation of apoptosis.The data obtained suggest that the raw material of Sosnovsky's hogweed claims to be a source of furanocoumarins, and the liposomal form, given the hydrophobic properties of furanocoumarins, is very suitable for creating a phototherapeutic drug.

Harnessing chlorin e6 loaded by functionalized iron oxide nanoparticles linked with glucose for target photodynamic therapy and improving of the immunogenicity of lung cancer

BACKGROUND

Non-small-cell lung cancer (NSCLC) is the most common malignant lung tumor and is difficult to be eradicated due to its immunosuppressive microenvironment. Chlorin e6 (Ce6)-mediated photodynamic therapy (PDT) could improve immunogenicity while destroying malignant tumor cells. However, the clinic application of Ce6-mediated PDT is limited by Ce6's poor water solubility and insufficient accumulation in lung cancer. To address this issue, Ce6 was loaded onto functionalized iron oxide nanoparticles linked with glucose to improve the distribution of Ce6 in lung cancer.

MATERIALS AND RESULTS

The results of transmission electron microscopy (TEM), UV-Vis spectrophotometry, dynamic light scattering and near-infrared (NIR) spectroscopy confirmed the successful preparation of the composites. Confocal and flow cytometry showed IO-PG-GLU-Ce6 significantly enhanced the uptake of Ce6 by lung cancer cells and produced more reactive oxygen species (ROS) under NIR light irradiation. In addition, the detection of cell viability, proliferation and apoptosis indicated IO-PG-GLU-Ce6 achieved stronger photo-toxicity to lung cancer cells. Moreover, IO-PG-GLU-Ce6 treatment effectively damaged the DNA of lung cancer cells and thereby activated STING, up-regulated the expression of IFN-β, HMGB1 and HSP90, indicating augmented immunogenicity of lung cancer cells. Further results of in vivo, organ imaging and tissue fluorescence sections demonstrated IO-PG-GLU-Ce6 significantly improved the distribution of Ce6 in tumor tissues of lung cancer-bearing mice as well. Finally, the findings of in vivo study and immunohistochemistry confirmed the better efficacy of IO-PG-GLU-Ce6. HE staining results of vital organs suggested that the composites were less toxic.

CONCLUSION

In conclusion, Ce6 loaded by functionalized iron oxide nanoparticles linked with glucose exhibited both target photodynamic efficacy and the ability to enhance its immunogenicity in lung cancer. This study provides a promising strategy for augment of the targeting delivery of Ce6 and its mediated photodynamic and immunotherapy.

Re-engineered imaging agent using biomimetic approaches

Recent progress in biomedical technology, the clinical bioimaging, has a greater impact on the diagnosis, treatment, and prevention of disease, especially by early intervention and precise therapy. Varieties of organic and inorganic materials either in the form of small molecules or nano-sized materials have been engineered as a contrast agent (CA) to enhance image resolution among different tissues for the detection of abnormalities such as cancer and vascular occlusion. Among different innovative imaging agents, contrast agents coupled with biologically derived endogenous platform shows the promising application in the biomedical field, including drug delivery and bioimaging. Strategy using biocomponents such as cells or products of cells as a delivery system predominantly reduces the toxic behavior of its cargo, as these systems reduce non-specific distribution by navigating its cargo toward the targeted location. The hypothesis is that depending on the original biological role of the naïve cell, the contrast agents carried by such a system can provide corresponding natural designated behavior. Therefore, by combining properties of conventional synthetic molecules and nanomaterials with endogenous cell body, new solutions in the field of bioimaging to overcome biological barriers have been offered as innovative bioengineering. In this review, we will discuss the engineering of cell and cell-derived components as a delivery system for various contrast agents to achieve clinically relevant contrast for diagnosis and study underlining mechanism of disease progression. This article is categorized under: Nanotechnology Approaches to Biology > Cells at the Nanoscale Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Complementing Cancer Photodynamic Therapy with Ferroptosis through Iron Oxide Loaded Porphyrin-Grafted Lipid Nanoparticles

Nanomaterials that combine multimodality imaging and therapeutic functions within a single nanoplatform have drawn extensive attention for molecular medicines and biological applications. Herein, we report a theranostic nanoplatform based on a relatively smaller (<20 nm) iron oxide loaded porphyrin-grafted lipid nanoparticles (Fe₃O₄@PGL NPs). The amphiphilic PGL easily self-assembled on the hydrophobic exterior surface of ultrasmall Fe₃O₄ NPs, resulting in a final ultrasmall Fe₃O₄@PGL NPs with diameter of ∼10 nm. The excellent self-assembling nature of the as-synthesized PGL NPs facilitated a higher loading of porphyrins, showed a negligible dark toxicity, and demonstrated an excellent photodynamic effect against HT-29 cancer cells in vitro. The in vivo experimental results further confirmed that Fe₃O₄@PGL NPs were ideally qualified for both the fluorescence and magnetic resonance (MR) imaging guided nanoplatforms to track the biodistribution and therapeutic responses of NPs as well as to simultaneously trigger the generation of highly cytotoxic reactive oxygen species (ROS) necessary for excellent photodynamic therapy (PDT). After recording convincing therapeutic responses, we further evaluated the ability of Fe₃O₄@PGL NPs/Fe₃O₄@Lipid NPs for ferroptosis therapy (FT) via tumor microenvironment (TME) modulation for improved anticancer activity. We hypothesized that tumor-associated macrophages (TAMs) could significantly improve the efficacy of FT by accelerating the Fenton reaction in vitro. In our results, the Fe ions released in vitro directly contributed to the Fenton reaction, whereas the presence of RAW 264.7 macrophages further accelerated the ROS generation as observed by the fluorescence imaging. The significant increase in the ROS during the coincubation of NPs, endocytosed by HT-29 cells and RAW264.7 cells, further induced increased cellular toxicity of cancer cells.

Guiding Drug Through Interrupted Bloodstream for Potentiated Thrombolysis by C-Shaped Magnetic Actuation System In Vivo

Fast and effective thrombolysis using tissue plasminogen activator (tPA) is limited by the poor delivery efficiency of thrombolytic drugs, which is induced by an interrupted bloodstream and delayed recanalization. Existing magnetic micro/nanodrug-loaded robots used for targeted thrombotic therapy are limited by the complexity of the clinical verification of nanodrugs and the limited space of magnetic actuation systems. Herein, a general drug delivery strategy based on mass transportation theory for thrombolysis is presented, and an open space C-shaped magnetic actuation system with laser location and ultrasound imaging navigation for in vivo evaluation is developed. tPA can be guided through an interrupted bloodstream to the thrombi by the locomotion of magnetic nanoparticle swarms (MNSs), thereby improving the thrombolysis efficacy. Notably, this strategy is able to quickly establish a life channel to achieve time-critical recanalization, which is typically inaccessible using native tPA. Both in vitro and in vivo thrombolysis experiments demonstrate that the thrombus lysis efficacy significantly increases after the application of the MNS under a rotating magnetic field. This study provides an anticipated C-shaped magnetic actuation system for in vivo validation and also presents a clinically feasible drug delivery strategy for targeted thrombolytic therapy with minimal systemic tPA exposure.

Colloidal Self-Assembly Approaches to Smart Nanostructured Materials

Colloidal self-assembly refers to a solution-processed assembly of nanometer-/micrometer-sized, well-dispersed particles into secondary structures, whose collective properties are controlled by not only nanoparticle property but also the superstructure symmetry, orientation, phase, and dimension. This combination of characteristics makes colloidal superstructures highly susceptible to remote stimuli or local environmental changes, representing a prominent platform for developing stimuli-responsive materials and smart devices. Chemists are achieving even more delicate control over their active responses to various practical stimuli, setting the stage ready for fully exploiting the potential of this unique set of materials. This review addresses the assembly of colloids into stimuli-responsive or smart nanostructured materials. We first delineate the colloidal self-assembly driven by forces of different length scales. A set of concepts and equations are outlined for controlling the colloidal crystal growth, appreciating the importance of particle connectivity in creating responsive superstructures. We then present working mechanisms and practical strategies for engineering smart colloidal assemblies. The concepts underpinning separation and connectivity control are systematically introduced, allowing active tuning and precise prediction of the colloidal crystal properties in response to external stimuli. Various exciting applications of these unique materials are summarized with a specific focus on the structure-property correlation in smart materials and functional devices. We conclude this review with a summary of existing challenges in colloidal self-assembly of smart materials and provide a perspective on their further advances to the next generation.

An Integrated Strategy for Rapid Hemostasis during Tumor Resection and Prevention of Postoperative Tumor Recurrence of Hepatocellular Carcinoma by Antibacterial Shape Memory Cryogel

The inevitable bleeding during tumor resection greatly increases the risk of tumor recurrence caused by metastasis of cancer cells with blood, and hemostasis and prevention of post-operation tumor recurrence is still a challenge. However, a biomaterials approach for rapid hemostasis during tumor resection and simultaneous prevention of tumor recurrence is rarely reported. Here, zeolitic imidazolate framework (ZIF-8) nanoparticle-enhanced multinetwork cryogels are proposed which provide an integrated treatment regimen for rapid hemostasis through intraoperative blood trigger shape recovery and enhanced coagulation, and prevention of postoperative cancer recurrence via sonodynamic anticancer in a hepatocellular carcinoma model. A series of antibacterial shape memory multifunctional cryogels are synthesized based on glycidyl methacrylate-functionalized quaternized chitosan (QCSG), dopamine-modified hyaluronic acid (HA-DA), and hematoporphyrin monomethyl ether (HMME)-loaded dopamine-modified ZIF-8 (ZDH). Blood loss in different bleeding models confirms good hemostasis of ZIF-8 loading cryogels. Besides, in vitro tests confirm that QCSG/HA-DA/ZDH (QH/ZDH) cryogels significantly killed cancer cells by generating reactive oxygen species under ultrasound. Finally, significantly reduced tumor recurrence after the resection of ectopic hepatocellular carcinoma further confirms the good effect of QH/ZDH cryogels in preventing recurrence by a coordinated strategy of intraoperative hemostasis and postoperative sonodynamic therapy by pH-responsive HMME release, showing great potential in clinical application.

Efficient Delivery of Chlorin e6 by Polyglycerol-Coated Iron Oxide Nanoparticles with Conjugated Doxorubicin for Enhanced Photodynamic Therapy of Melanoma

Chlorin e6 (Ce6) is a promising photosensitizer for tumor photodynamic therapy (PDT). However, the efficacy of Ce6 PDT is limited by Ce6's poor water solubility, rapid blood clearance, and inadequate accumulation in the tumor tissue. This problem is tackled in this work, wherein functionalized superparamagnetic iron oxide nanoparticles (IO-NPs) were used as carriers to deliver Ce6 to melanoma. The IO-NPs were coated with polyglycerol (PG) to afford good aqueous solubility. The chemotherapeutic agent doxorubicin (DOX) was attached to the PG coating via the hydrazone bond to afford affinity to the cell membrane and thereby promote the cell uptake. The hydrophobic nature of DOX also induced the aggregation of IO-NPs to form nanoclusters. Ce6 was then loaded onto the IO nanoclusters through physical adsorption and coordination with surface iron atoms, yielding the final composites IO-PG-DOX-Ce6. In vitro experiments showed that IO-PG-DOX-Ce6 markedly increased Ce6 uptake in mouse melanoma cells, leading to much-enhanced photocytotoxicity characterized by intensified reactive oxygen species production, loss of viability, DNA damage, and stimulation of tumor cell immunogenicity. In vivo experiments corroborated the in vitro findings and demonstrated prolonged blood clearance of IO-PG-DOX-Ce6. Importantly, IO-PG-DOX-Ce6 markedly increased the Ce6 distribution and retention in mouse subcutaneous melanoma grafts and significantly improved the efficacy of Ce6-mediated PDT. No apparent vital organ damage was observed at the same time. In conclusion, the IO-PG-DOX NPs provide a simple and safe delivery platform for efficient tumor enrichment of Ce6, thereby enhancing antimelanoma PDT.

Fe3O4@Pt nanoparticles to enable combinational electrodynamic/chemodynamic therapy

Electrodynamic therapy (EDT) has recently emerged as a potential external field responsive approach for tumor treatment. While it presents a number of clear superiorities, EDT inherits the intrinsic challenges of current reactive oxygen species (ROS) based therapeutic treatments owing to the complex tumor microenvironment, including glutathione (GSH) overexpression, acidity and others. Herein for the first time, iron oxide nanoparticles are decorated using platinum nanocrystals (Fe₃O₄@Pt NPs) to integrate the current EDT with chemodynamic phenomenon and GSH depletion. Fe₃O₄@Pt NPs can effectively induce ROS generation based on the catalytic reaction on the surface of Pt nanoparticles triggered by electric field (E), and meanwhile it may catalyze intracellular H₂O₂ into ROS via Fenton reaction. In addition, Fe³⁺ ions released from Fe₃O₄@Pt NPs under the acidic condition in tumor cells consume GSH in a rapid fashion, inhibiting ROS clearance to enhance its antitumor efficacy. As a result, considerable in vitro and in vivo tumor inhibition phenomena are observed. This study has demonstrated an alternative concept of combinational therapeutic modality with superior efficacy.

Overcoming barriers in photodynamic therapy harnessing nano-formulation strategies

Photodynamic therapy (PDT) has been extensively investigated for decades for tumor treatment because of its non-invasiveness, spatiotemporal selectivity, lower side-effects, and immune activation ability. It can be a promising treatment modality in several medical fields, including oncology, immunology, urology, dermatology, ophthalmology, cardiology, pneumology, and dentistry. Nevertheless, the clinical application of PDT is largely restricted by the drawbacks of traditional photosensitizers, limited tissue penetrability of light, inefficient induction of tumor cell death, tumor resistance to the therapy, and the severe pain induced by the therapy. Recently, various photosensitizer formulations and therapy strategies have been developed to overcome these barriers. Significantly, the introduction of nanomaterials in PDT, as carriers or photosensitizers, may overcome the drawbacks of traditional photosensitizers. Based on this, nanocomposites excited by various light sources are applied in the PDT of deep-seated tumors. Modulation of cell death pathways with co-delivered reagents promotes PDT induced tumor cell death. Relief of tumor resistance to PDT with combined therapy strategies further promotes tumor inhibition. Also, the optimization of photosensitizer formulations and therapy procedures reduces pain in PDT. Here, a systematic summary of recent advances in the fabrication of photosensitizers and the design of therapy strategies to overcome barriers in PDT is presented. Several aspects important for the clinical application of PDT in cancer treatment are also discussed.

Transforming growth factor-β blockade modulates tumor mechanical microenvironments for enhanced antitumor efficacy of photodynamic therapy

Photodynamic therapy (PDT) is frequently used in cancer treatment in clinical settings. However, its applications in stroma-rich solid tumors, e.g., triple negative breast cancer, are limited by abnormal mechanical microenvironments. Solid stress accumulated in stroma-rich solid tumors compresses tumor blood vessels, hampers the delivery of photosensitizers (PSs) in tumor tissues, and poses a major challenge for potent PDT. Here, we report a novel combination strategy to augment PDT based cancer therapy by combining hydroxyethyl starch-chlorin e6 conjugate self-assembled nanoparticles (HES-Ce6 NPs) with the transforming growth factor-β (TGFβ) inhibitor LY2157299 (LY). HES-Ce6 conjugates, as synthesized by one step esterification reaction, could self-assemble into uniform HES-Ce6 NPs, which exhibited enhanced photostability and generated more reactive oxygen species (ROS) under 660 nm laser irradiation than free Ce6. Prior to PDT, intragastric administration of LY decreased collagen deposition, alleviated solid stress, and decompressed tumor blood vessels. As a result, the reconstructed tumor mechanical microenvironment promoted accumulation and penetration of HES-Ce6 NPs into tumor tissues, contributing to augmented antitumor efficacy of HES-Ce6 NP mediated PDT. Modulating tumor mechanical microenvironments using TGFβ blockade to enhance the delivery of PSs in tumors with excessive extracellular matrix represents an efficient strategy for treating stroma-rich solid tumors.

An albumin-binding dimeric prodrug nanoparticle with long blood circulation and light-triggered drug release for chemo-photodynamic combination therapy against hypoxia-induced metastasis of lung cancer

Photodynamic therapy (PDT) has been widely used in cancer therapy, but its therapeutic effect is reduced by the aggravating hypoxic microenvironment via upregulating hypoxia-associated proteins and promoting tumor metastasis. To mitigate these issues, we designed an albumin-binding and light-triggered core-shell dimeric prodrug nanoparticle to inhibit hypoxia-induced tumor metastasis and enhance the PDT efficacy. The prodrug nanoparticles, Ce6&DHA-S-DHA@CMN NPs (CDC NPs), were prepared using a single thioether-linked dihydroartemisinin (DHA) dimer co-encapsulated with Chlorin e6 (Ce6) and stabilized by albumin-capturing maleimide- and hypoxia-sensitive 2-nitroimidazole-modified carboxymethyl chitosan (CMCTS-MAL&NI, CMN for short). Upon laser irradiation, Ce6 could generate reactive oxygen species (ROS), which not only exerted the effect of the PDT but also broke the ROS-sensitive single thioether bridge in the dimeric prodrug DHA-S-DHA, thus accelerating the disassembly of the nanoparticles. DHA-S-DHA served as both an ROS-responsive carrier for Ce6 and a chemotherapeutic drug, synergizing with PDT and inhibiting tumor metastasis by downregulating hypoxia-inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF). Polyethylene glycol (PEG) modification has been widely used to stabilize hydrophobic prodrug nanoparticles and prolong the circulation time, but the PEGylated nanoparticles always suffer from accelerated blood clearance (ABC), a phenomenon which restricts their application severely. In this study, PEG was replaced by an amphipathic micelle, CMN, which could specifically capture albumin in the blood, conferring the nanoparticles long circulation and no ABC phenomenon. Under the aggravating hypoxic condition during PDT, the conversion of 2-nitroimidazole groups to 2-aminoimidazole groups in CMN could destabilize the structure of the shell and accelerate drug release. Results showed that the novel CDC NPs exhibited unique advantages in chemo-photodynamic combination therapy, such as long systemic circulation, high tumor accumulation, light-triggered drug release, HIF-1α/VEGF downregulation, and anti-metastasis efficacy, which provided a new route to overcome the ABC phenomenon of the PEGylated prodrug nanoparticles and reverse the hypoxia-induced metastasis simultaneously.

Thermo-Triggered In Situ Chitosan-Based Gelation System for Repeated and Enhanced Sonodynamic Therapy Post a Single Injection

Sonodynamic therapy (SDT) by utilizing ultrasonic waves triggers the generation of reactive oxygen species (ROS) with the help of sonosensitizers to destruct deep-seated tumors has attracted great attention. However, the efficacy of SDT may not be robust enough due to the insufficient oxygen supply within solid tumors. Additionally, repeated injections and treatments, which are often required to achieve the optimal therapeutic responses, may cause additional side effects and patient incompliance. Herein, a thermo-triggered in situ hydrogel system is developed in which catalase (CAT) conjugated with sonosensitizer meso-tetra (4-carboxyphenyl) porphine (TCPP) is mixed into chitosan (CS) and beta-glycerol phosphate disodium (GP) to form the precursor solution. After injection of the precursor solution into tumors, the in situ sol-gel transformation will occur as triggered by the body temperature, resulting in the localized tumor retention of TCPP-CAT. The locally restrained TCPP-CAT not only produces ROS under ultrasonic treatment, but also sustainably reverses the oxygen-deficient status in solid tumors by triggering the O₂ generation from the decomposition of endogenous H₂ O₂ , further promoting the efficacy of SDT. As a result, the repeated SDT after a single dose injection of such a hydrogel can offer robust treatment effects to effectively eradicate tumors.

A versatile nanocomposite based on nanoceria for antibacterial enhancement and protection from aPDT-aggravated inflammation via modulation of macrophage polarization

Antibacterial photodynamic therapy (aPDT) is of vital importance for the treatment of periodontal diseases due to its great potential on effective elimination of pathogenic bacteria via overwhelming reactive oxygen species (ROS) generation. However, the excessive ROS after the therapeutic process may impose an oxidative stress within periodontal pockets, consequently leading to an irreversible destroy in surrounding tissue and severely limit its biomedical applications. In this study, considering the contradiction between ROS in bacteriostasis and inflammation, the role of ROS in different temporal and spatial states has been fully studied. Accordingly, we have designed composite nanomaterials that can play ROS based aPDT and anti-inflammatory effect by eliminating ROS, taking account of different ratio of photosensitizer/ROS scavenger to realize a time-sequential manner. Herein, a simple multifunctional nanocomposite was fabricated by coating red light-excited photosensitizer chlorin e6 (Ce6) onto nanoceria, achieving simultaneous sterilization and inflammation elimination via a dual directional regulation effect. This nano-based platform could utilize the aPDT for antibacterial purpose in the first stage with red-light irradiation, and subsequently scavenge the residual ROS via nanoceria to modulate host immunity by down-regulating the M1 polarization (pro-inflammatory) of macrophages and up-regulating the M2 polarization (anti-inflammatory and regenerative) of macrophages. Moreover, the local ROS level induced by activated inflammation pathway can be adjusted in a very long time because of the charge conversion effect of CeO₂. The regenerative potential of inflammatory surrounding tissues was improved in the animal model. Our strategy will open a new inspiration to fight against the defects of aPDT in the treatment of periodontal disease, even in the anti-infection therapy for the future clinical application.

Integrating Nanotherapeutic Platforms to Image Guided Approaches for Management of Cancer

Cancer is a leading cause of mortality worldwide, accounting for 8.8 million deaths in 2015. The landscape of cancer therapeutics is rapidly advancing with development of new and sophisticated approaches to diagnostic testing. Treatment plan for early diagnosed patients include radiation therapy, tumor ablation, surgery, immunotherapy and chemotherapy. However the treatment can only be initiated when the cancer has been diagnosed thoroughly. Theranostics is a term that combines diagnostics with therapeutics. It embraces multiple techniques to arrive at comprehensive diagnosis, molecular images and an individualized treatment regimen. Recently, there is an effort to tangle the emerging approach with nanotechnologies, in an attempt to develop theranostic nanoplatforms and methodologies. Theranostic approach to management of cancer offers numerous advantages. They are designed to monitor cancer treatment in real time. A wide variety of theranostic nanoplatforms that are based on diverse nanostructures like magnetic nanoparticles, carbon nanotubes, gold nanomaterials, polymeric nanoparticles and silica nanoparticles showed great potential as cancer theranostics. Nano therapeutic platforms have been successful in integrating image guidance with targeted approach to treat cancer.

Multifunctional DNA Polymer-Assisted Upconversion Therapeutic Nanoplatform for Enhanced Photodynamic Therapy

Although considerable clinical attempts on various kinds of cancers have been made, photodynamic therapy (PDT) still suffers from attenuated therapeutic effects because of the developed resistance of cancer cells. As a novel antiapoptosis protein, survivin has been demonstrated to be selectively overexpressed in a great number of human malignancies and plays a significant part in cancer progression and therapeutic resistance. Herein, we present an upconversion nanoplatform for enhanced PDT by DNAzyme-mediated gene silencing of survivin. In our system, a long single-stranded DNA (ssDNA) with a repetitive aptamer (AS1411) and survivin-targeted DNAzyme was fabricated by rolling circle amplification (RCA) and adsorbed on the upconversion nanoparticles (UCNPs) by electrostatic attraction. The multivalence of the ssDNA endows the upconversion nanoplatform with high recognition and loading capacity of photosensitizers and DNAzymes. When the nanoplatform is targeted internalized into cancer cells, PDT can be triggered by near-infrared (NIR) light to generate reactive oxygen species (ROS) for killing the cancer cells. Moreover, the encoded DNAzyme can efficiently inhibit the gene expression of survivin, providing the potential to enhance the efficiency of PDT. This study thus highlights the promise of an upconversion photodynamic nanoplatform for admirable combination therapy in cancer.

A Dual Functional Nanoreactor for Synergistic Starvation and Photodynamic Therapy

The combination of photodynamic therapy (PDT) and enzyme therapy is a highly desirable approach in malignant tumor therapies as it takes advantage of the spatial-controlled PDT and the effective enzyme-catalyzed bioreactions. However, it is a challenge to co-encapsulate hydrophilic enzymes and hydrophobic photosensitizers, and these two agents often interfere with each other. In this work, a protocell-like nanoreactor (GOx-MSN@MnPc-LP) has been designed for synergistic starvation therapy and PDT. In this nanoreactor, the hydrophilic glucose oxidase (GOx) is loaded in the pore of mesoporous silica nanoparticles (MSNs), while the hydrophobic manganese phthaleincyanide (MnPc) is loaded in the membrane layer of liposome. This spatial separation of two payloads protects GOx and MnPc from the cellular environment and avoids interference with each other. GOx catalyzes the oxidation of glucose, which generates hydrogen peroxide and gluconic acid, leading to the starvation therapy via glucose consumption in cancer cells, as well as the disruption of cellular redox balance. MnPc produces cytotoxic singlet oxygen under 730 nm laser irradiation, achieving PDT. The antitumor effects of the nanoreactor have been verified on tumor cells and tumor-bearing mice models. GOx-MSN@MnPc-LP efficiently inhibits tumor growth in vivo with a single treatment, indicating the robust synergy of starvation therapy and PDT treatment. This work also offers a versatile strategy for delivering hydrophilic enzymes and hydrophobic photosensitizers using a protocell-like nanoreactor for effective cancer treatment.

Protein-drug conjugate programmed by pH-reversible linker for tumor hypoxia relief and enhanced cancer combination therapy

Combining functional proteins with small molecular drugs into one entity may endow distinct synergistic advantages. However, on account of completely different physicochemical properties of such payloads, co-delivery through systemic administration for therapeutic purpose is challenging. Herein, we designed the protein-drug conjugate HSAP-DC-CAT (human serum albumin/Pt (IV)-dibenzocyclooctyne/chlorin e6-catalase) by modification of CAT and cisplatin pro-drug loaded HSA with pH-sensitive azide linker 3-(azidomethyl)-4-methyl-2,5-furandione (AzMMMan) followed by click chemistry assembly with DC. The dynamic covalent bonds between linker and proteins, on the one hand, can bridge proteins and small molecular drugs in the intermediate state for systemic delivery in the harsh in vivo environment; on the other hand, it can trigger traceless cleavage and release of drugs and proteins with full bioactivity in acidic microenvironment of tumor. The multifunctional HSAP-DC-CAT provides efficient cytosolic transduction in vitro, excellent blood half-lives after systemic administration, and significant antitumor outcome via integrated cisplatin-based chemotherapy and Ce6-based photodynamic therapy enhanced by catalase-induced manipulation of tumor hypoxia microenvironment. This study describes a universal formulation strategy for protein and small molecular drug by a bifunctional linker through amide reaction and click chemistry, with traceless in vivo release of therapeutic units.

Recent Advancements of Magnetic Nanomaterials in Cancer Therapy

Magnetic nanomaterials belong to a class of highly-functionalizable tools for cancer therapy owing to their intrinsic magnetic properties and multifunctional design that provides a multimodal theranostics platform for cancer diagnosis, monitoring, and therapy. In this review article, we have provided an overview of the various applications of magnetic nanomaterials and recent advances in the development of these nanomaterials as cancer therapeutics. Moreover, the cancer targeting, potential toxicity, and degradability of these nanomaterials has been briefly addressed. Finally, the challenges for clinical translation and the future scope of magnetic nanoparticles in cancer therapy are discussed.

Tetraphenylporphine-Modified Polymeric Nanoparticles Containing NIR Photosensitizer for Mitochondria-Targeting and Imaging-Guided Photodynamic Therapy

Near-infrared (NIR) photodynamic therapy (PDT) is a promising antitumor strategy under NIR light irradiation to kill cancer cells. Mitochondria has a critical function in sustaining cellular viability and death, which is the ideal organelle for PDT. Here, we reported a tetraphenylporphine (TPP)-conjugated amphiphilic copolymer and an iodinated boron dipyrromethene photosensitizer (BDPI) with high singlet oxygen yield to form nanoparticles (PBDPI-TPP), which could realize mitochondria-targeting and improve the NIR imaging-guided PDT. The as-prepared mitochondria-targeting nanoplatform could show effective subcellular localization and bring about significant irreversible mitochondrial injury for enhanced PDT. Both in vitro and in vivo experiments revealed that the mitochondria-targeting PDT system could achieve a remarkable therapeutic effect, indicating that it is a promising nanoplatform for NIR imaging-guided PDT in cancer therapeutics.

Soft and Condensed Nanoparticles and Nanoformulations for Cancer Drug Delivery and Repurpose

Drug repurpose or reposition is recently recognized as a high-performance strategy for developing therapeutic agents for cancer treatment. This approach can significantly reduce the risk of failure, shorten R&D time, and minimize cost and regulatory obstacles. On the other hand, nanotechnology-based delivery systems are extensively investigated in cancer therapy due to their remarkable ability to overcome drug delivery challenges, enhance tumor specific targeting, and reduce toxic side effects. With increasing knowledge accumulated over the past decades, nanoparticle formulation and delivery have opened up a new avenue for repurposing drugs and demonstrated promising results in advanced cancer therapy. In this review, recent developments in nano-delivery and formulation systems based on soft (i.e., DNA nanocages, nanogels, and dendrimers) and condensed (i.e., noble metal nanoparticles and metal-organic frameworks) nanomaterials, as well as their theranostic applications in drug repurpose against cancer are summarized.

Multifunctional phototheranostic nanomedicine for cancer imaging and treatment

Cancer, as one of the most life-threatening diseases, shows a high fatality rate around the world. When improving the therapeutic efficacy of conventional cancer treatments, researchers also conduct extensive studies into alternative therapeutic approaches, which are safe, valid, and economical. Phototherapies, including photodynamic therapy (PDT) and photothermal therapy (PTT), are tumor-ablative and function-reserving oncologic interventions, showing strong potential in clinical cancer treatment. During phototherapies, the non-toxic phototherapeutic agents can be activated upon light irradiation to induce cell death without causing much damage to normal tissues. Besides, with the rapid development of nanotechnology in the past decades, phototheranostic nanomedicine also has attracted tremendous interests aiming to continuously refine their performance. Herein, we reviewed the recent progress of phototheranostic nanomedicine for improved cancer therapy. After a brief introduction of the therapeutic principles and related phototherapeutic agents for PDT and PTT, the existing works on developing of phototheranostic nanomedicine by mainly focusing on their categories and applications, particularly on phototherapy-synergized cancer immunotherapy, are comprehensively reviewed. More importantly, a brief conclusion and future challenges of phototheranostic nanomedicine from our point of view are delivered in the last part of this article.

Magnetic Targeting of mTHPC To Improve the Selectivity and Efficiency of Photodynamic Therapy

Photodynamic therapy (PDT) is a promising recognized treatment for cancer. To date, PDT drugs are injected systemically, and the tumor area is irradiated to induce cell death. Current clinical protocols have several drawbacks, including limited accessibility to solid tumors and insufficient selectivity of drugs. Herein, we propose an alternative approach to improve PDT effectiveness by magnetic targeting of responsive carriers conjugated to the PDT drug. We coordinatively attached a meso-tetrahydroxyphenylchlorin (mTHPC) photosensitizer to Ce-doped-γ-Fe₂O₃ maghemite nanoparticles (MNPs). These MNPs are superparamagnetic and biocompatible, and the resulting mTHPC-MNPs nanocomposites are stable in aqueous suspensions. MDA-MB231 (human breast cancer) cells incubated with the mTHPC-MNPs showed high uptake and high death rates in cell population after PDT. The exposure to external magnetic forces during the incubation period directed the nanocomposites to selected sites enhancing drug accumulation that was double that of cells with no magnetic exposure. Next, breast cancer tumors were induced subcutaneously in mice and treated magnetically. In vivo results showed accelerated drug accumulation in tumors of mice injected with mTHPC-MNP nanocomposites, compared to the free drug. PDT irradiation led to a decrease in tumor size of both groups, whereas treatment with the focused magnetic nanocomposites led to significant tumor regression. Our results demonstrate a method to improve the current PDT treatments by applying magnetic forces to effectively direct the drug to cancerous tissue. This approach leads to a highly localized and effective PDT process, opening new directions for clinical PDT protocols.

Superparamagnetic iron oxide nanoparticulate system: synthesis, targeting, drug delivery and therapy in cancer

Cancer is a global epidemic and is considered a leading cause of death. Various cancer treatments such as chemotherapy, surgery, and radiotherapy are available for the cure but those are generally associated with poor long-term survival rates. Consequently, more advanced and selective methods that have better outcomes, fewer side effects, and high efficacies are highly in demand. Among these is the use of superparamagnetic iron oxide nanoparticles (SPIONs) which act as an innovative kit for battling cancer. Low cost, magnetic properties and toxicity properties enable SPIONs to be widely utilized in biomedical applications. For example, magnetite and maghemite (Fe3O4 and γ-Fe2O3) exhibit superparamagnetic properties and are widely used in drug delivery, diagnosis, and therapy. These materials are termed SPIONs when their size is smaller than 20 nm. This review article aims to provide a brief introduction on SPIONs, focusing on their fundamental magnetism and biological applications. The quality and surface chemistry of SPIONs are crucial in biomedical applications; therefore an in-depth survey of synthetic approaches and surface modifications of SPIONs is provided along with their biological applications such as targeting, site-specific drug delivery and therapy.

Role of Cholesterol Conjugation in the Antibacterial Photodynamic Therapy of Branched Polyethylenimine-Containing Nanoagents

Photodynamic therapy is a promising approach for fighting bacterial infections because it can induce few side effects, develop no drug resistance, and realize precise treatment. However, most photosensitizers (PSs) have the disadvantages of poor water-solubility, severe self-quenching, and potential toxicity. Here, the cationic polymer polyethyleneimine (PEI) was used to prepare a cholesterol- and chlorin e6 (Ce6, a common PS)-conjugated compound via the carboxyl-amine reaction or the acyl chloride-amine reaction (abbreviated as Chol-PEI-Ce6). The as-prepared Chol-PEI-Ce6 molecules can self-assemble into close-to-spherical nanoparticles (NPs) with an average diameter of ∼15 nm and can bind to the bacterial surfaces via the synergistic hydrophobic insertion of the cholesterol moieties and electrostatic interaction between the cationic amine groups of PEI and the bacterial surfaces. Upon light irradiation, the NPs can effectively inactivate both Gram-positive and Gram-negative bacteria. Besides, the interaction between Chol-PEI-Ce6 NPs and bacteria markedly enhances the production of intracellular reactive oxygen species after light irradiation, which may account for the excellent antibacterial performance of the NPs. More importantly, the NPs possess negligible dark cytotoxicity and good hemocompatibility. Therefore, the present work may have strong implications for developing novel antibacterial agents to fight against bacterial infections.

A Multiresponsive Nanohybrid to Enhance the Lysosomal Delivery of Oxygen and Photosensitizers

Photodynamic therapy (PDT) is a promising cancer ablation method, but its efficiency is easily affected by several factors, such as the insufficient delivery of photosensitizers, low oxygen levels as well as long distance between singlet oxygen and intended organelles. A multifunctional nanohybrid, named MGAB, consisting of gelatin-coated manganese dioxide and albumin-coated gold nanoclusters, was designed to overcome these issues by improving chlorin e6 (Ce6) delivery and stimulating oxygen production in lysosomes. MGAB were quickly degraded in a high hydrogen peroxide, high protease activity, and low pH microenvironment, which is closely associated with tumor growth. The Ce6-loaded MGAB were picked up by tumor cells through endocytosis, degraded within the lysosomes, and released oxygen and photosensitizers. Upon near-infrared light irradiation, the close proximity of oxygen with photosensitizer within lysosomes enabled the production of cytotoxic singlet oxygen, resulting in more effective PDT.

Porphyrinoid-based photosensitizers for diagnostic and therapeutic applications: An update

Porphyrin-based molecules are actively studied as dual function theranostics: fluorescence-based imaging for diagnostics and fluorescence-guided therapeutic treatment of cancers. The intrinsic fluorescent and photodynamic properties of the bimodal molecules allows for these theranostic approaches. Several porphyrinoids bearing both hydrophilic and/or hydrophobic units at their periphery have been developed for the aforementioned applications, but better tumor selectivity and high efficacy to destroy tumor cells is always a key setback for their use. Another issue related to their effective clinical use is that, most of these chromophores form aggregates under physiological conditions. Nanomaterials that are known to possess incredible properties that cannot be achieved from their bulk systems can serve as carriers for these chromophores. Porphyrinoids, when conjugated with nanomaterials, can be enabled to perform as multifunctional nanomedicine devices. The integrated properties of these porphyrinoid-nanomaterial conjugated systems make them useful for selective drug delivery, theranostic capabilities, and multimodal bioimaging. This review highlights the use of porphyrins, chlorins, bacteriochlorins, phthalocyanines and naphthalocyanines as well as their multifunctional nanodevices in various biomedical theranostic platforms.

Polydopamine-Based Nanocarriers for Photosensitizer Delivery

Photodynamic therapy (PDT) has emerged as a non-invasive modality for treating tumors while a photosensitizer (PS) plays an indispensable role in PDT. Nevertheless, free PSs are limited by their low light stability, rapid blood clearance, and poor water solubility. Constructing a nanocarrier delivering PSs is an appealing and potential way to solve these issues. As a melanin-like biopolymer, polydopamine (PDA) is widely utilized in biomedical applications (drug delivery, tissue engineering, and cancer therapy) for its prominent properties, including favorable biocompatibility, easy preparation, and versatile functionality. PDA-based nanocarriers are thus leveraged to overcome the inherent shortcomings of free PSs. In this Mini-Review, we will firstly present an overview on the recent developments of PDA nanocarriers delivering PSs. Then, we introduce three distinctive strategies developed to combine PSs with PDA nanocarriers. The advantages and disadvantages of each strategy will be discussed. Finally, the current challenges and future opportunities of PDA-based PS nanocarriers will also be addressed.

Nanoconjugation and Encapsulation Strategies for Improving Drug Delivery and Therapeutic Efficacy of Poorly Water-Soluble Drugs

Nanoconjugations have been demonstrated to be a dominant strategy for drug delivery and biomedical applications. In this review, we intend to describe several strategies for drug formulation, especially to improve the bioavailability of poorly water-soluble molecules for future application in the therapy of numerous diseases. The context of current studies will give readers an overview of the conjugation strategies for fabricating nanoparticles, which have expanded from conjugated materials to the surface conjugation of nanovehicles. Moreover, nanoconjugates for theranostics are also discussed and highlighted. Overall, these state-of-the-art conjugation methods and these techniques and applications for nanoparticulate systems of poorly water-soluble drugs will inspire scientists to explore and discover more productive techniques and methodologies for drug development.

Iron Nanoparticles for Low-Power Local Magnetic Hyperthermia in Combination with Immune Checkpoint Blockade for Systemic Antitumor Therapy

Magnetic hyperthermia (MHT) utilizing heat generated by magnetic nanoparticles under alternating magnetic field (AMF) is an effective local tumor ablation method but can hardly treat metastatic tumors. In this work, we discover that pure iron nanoparticles (FeNPs) with high magnetic saturation intensity after being modified by biocompatible polymers are stable in aqueous solution and could be employed as a supereffective MHT agent to generate sufficient heating under a low-power AFM. Effective MHT ablation of tumors is then achieved, using either locally injected FeNPs or intravenously injected FeNPs with the help of locally applied tumor-focused constant magnetic field to enhance the tumor accumulation of those nanoparticles. We further demonstrate that the combination of FeNP-based MHT with local injection of nanoadjuvant and systemic injection of anticytotoxic T-lymphocyte antigen-4 (anti-CTLA4) checkpoint blockade would result in systemic therapeutic responses to inhibit tumor metastasis. A robust immune memory effect to prevent tumor recurrence is also observed after the combined MHT-immunotherapy. This work not only highlights that FeNPs with appropriate surface modification could act as a supereffective MHT agent but also presents the great promises of combining MHT with immunotherapy to achieve long-lasting systemic therapeutic outcome after local treatment.