Multistage Targeting Strategy Using Magnetic Composite Nanoparticles for Synergism of Photothermal Therapy and Chemotherapy

Nanomedicine in Cancer Therapeutics: Current Perspectives from Bench to Bedside

Cancer is among the leading causes of death worldwide, with projections indicating that it will claim 35 million lives by the year 2050. Conventional therapies, such as chemotherapy and immune modulation, have reduced cancer mortality to some extent; however, they have limited efficacy due to their broad mode of action, often resulting in cytotoxic effects on normal cells along with the malignant tissues, ultimately limiting their overall optimal therapeutic efficacy outcomes.Rapid advances in nanotechnology and an evolving understanding of cancer mechanisms have propelled the development of a diverse array of nanocarriers to vanquish the hurdles in achieving sophisticated drug delivery with reduced off-target toxicity. Nanoformulations can deliver the anti-cancer agents precisely to the tumor cell by integrating a multitarget approach that allows for tissue-, cell-, or organelle-specific delivery and internalization. Despite the immense interest and unmatched advancements in modern oncology equipped with nanomedicines, only a few nanoformulations have successfully translated into clinical settings. A major reason behind this shortcoming is the lack of a rationale design incorporating smart, responsive targeting features, leading to a compromised therapeutic window due to inefficient internalization or erroneous intracellular localization with unsuccessful payload release. This review aims to summarize the recent perspective of nanomedicine and its translation to clinical practice, with a particular focus on the evolution of strategies used in tumor targeting from traditional EPR-based passive mechanisms to advanced active and multi-stage approaches. We highlight the coupling of organelle-specific and stimuli-responsive nanocarriers, discuss the potential of biomimetic and cell-mediated delivery systems, and also shed light on technologies such as microfluidics, tumor-on-chip models, and AI-assisted synthesis. Finally, this review explores translational hurdles ranging from biological and manufacturing challenges to regulatory bottlenecks and outlines how innovative modeling systems and engineering solutions can bridge the gap from bench to bedside in cancer nanotherapeutics.

Dissolving Microneedle Patches Integrating Optical Clearing and Photothermal Agents for Improved Photothermal Disinfection

Photothermal disinfection is an emerging and efficient therapeutic method for treating various infections. However, the therapeutic efficacy is hindered by the poor tissue penetration of light. While tissue optical clearance technology can enhance light transmission, the stratum corneum impedes the delivery of clearing agents to deeper tissues. Herein, dissolving microneedle (DMN) patches incorporating optical clearing and photothermal agents are developed for improved photothermal disinfection. Such DMN patches are obtained using sucrose as the optical clearing agent and polydopamine (PDA) nanoparticles as photothermal agents in poly(vinyl alcohol) (PVA) DMN matrix. After treatment with the composite DMN, the light transmittance of the pigskin increased by 4.75 times. The composite DMNs deliver PDAs to the subsurface of skin while improving the optical clearing effect, raising the temperature of the subsurface of pigskin to 45 °C under near-infrared (NIR) light irradiation with a wavelength of 808 nm. In treating a deep infection model (pigskin coverage) established on mouse skin, the composite DMNs significantly improve the wound recovery rate. This approach is expected to be a general strategy for enhancing the anti-infective efficacy of photothermal disinfection and shows great potential for improving the clinical application of various phototherapies.

Polydopamine-functionalized capsules: From design to applications

In recent years, polydopamine (PDA)-functionalized capsules have garnered significant interest from researchers in the field of materials, owing to its remarkable properties of adhesion, biocompatibility, photothermal conversion capabilities, chemical reactivity, and so on. At present, numerous studies have reported various structures and morphologies of PDA-functionalized capsules fabricated via diverse strategies, that have found applications across a broad spectrum of disciplines. However, there are few comprehensive and systematic reviews focusing on various preparation strategies of PDA-functionalized capsules with various structures. This paper systematically reviewed the preparation strategies and related applications of PDA-functionalized capsules. These strategies of PDA-functionalized capsules were discussed in detail from four parts including PDA-functionalized capsules based on hollow PDA, mesoporous PDA (MPDA), directly encapsulating emulsion, and surface modification of capsules. Then the review outlined the applications of PDA-functionalized capsules in biomedicine, energy, textiles, and the environment. Furthermore, this review summarized the current research findings on PDA-functionalized capsules and outlines their future development directions. Overall, we aim for this review to inspire researchers and offer valuable guidance for the synthesis and application of advanced PDA-functionalized capsules.

Periodic Table of Immunomodulatory Elements and Derived Two-Dimensional Biomaterials

Periodic table of chemical elements serves as the foundation of material chemistry, impacting human health in many different ways. It contributes to the creation, growth, and manipulation of functional metallic, ceramic, metalloid, polymeric, and carbon-based materials on and near an atomic scale. Recent nanotechnology advancements have revolutionized the field of biomedical engineering to tackle longstanding clinical challenges. The use of nano-biomaterials has gained traction in medicine, specifically in the areas of nano-immunoengineering to treat inflammatory and infectious diseases. Two-dimensional (2D) nanomaterials have been found to possess high bioactive surface area and compatibility with human and mammalian cells at controlled doses. Furthermore, these biomaterials have intrinsic immunomodulatory properties, which is crucial for their application in immuno-nanomedicine. While significant progress has been made in understanding their bioactivity and biocompatibility, the exact immunomodulatory responses and mechanisms of these materials are still being explored. Current work outlines an innovative "immunomodulatory periodic table of elements" beyond the periodic table of life, medicine, and microbial genomics and comprehensively reviews the role of each element in designing immunoengineered 2D biomaterials in a group-wise manner. It recapitulates the most recent advances in immunomodulatory nanomaterials, paving the way for the development of new mono, hybrid, composite, and hetero-structured biomaterials.

Nuclear-Targeting Peptides for Cancer Therapy

Nucleus is the central regulator of cells that controls cell proliferation, metabolism, and cell cycle, and is considered the most important organelle in cells. The precision medicine that can achieve nuclear targeting has achieved good therapeutic effects in anti-tumor therapy. However, the presence of biological barriers such as cell membranes and nuclear membranes in cells limit the delivery of therapeutic agents to the nucleus. Therefore, developing effective nuclear-targeting drug delivery strategies is particularly important. Nuclear-targeting peptides are a class of functional peptides that can penetrate cell membranes and target the nucleus. They mainly recognize and bind to the nuclear transport molecules (such as Importin-α/β) and transport the therapeutic agents to the nucleus through nuclear pore complexes (NPC). This review summarizes the most recent developments of strategies for anti-tumor therapy utilizing nuclear-targeting peptides, which will ultimately contribute to the development of more effective nuclear-targeting strategies to achieve better anti-tumor outcomes.

Tailoring metal oxide nanozymes for biomedical applications: trends, limitations, and perceptions

Nanomaterials with enzyme-like properties are known as 'nanozymes'. Nanozymes are preferred over natural enzymes due to their nanoscale characteristics and ease of tailoring of their physicochemical properties such as size, structure, composition, surface chemistry, crystal planes, oxygen vacancy, and surface valence state. Interestingly, nanozymes can be precisely controlled to improve their catalytic ability, stability, and specificity which is unattainable by natural enzymes. Therefore, tailor-made nanozymes are being favored over natural enzymes for a range of potential applications and better prospects. In this context, metal oxide nanoparticles with nanozyme-mimicking characteristics are exclusively being used in biomedical sectors and opening new avenues for future nanomedicine. Realising the importance of this emerging area, here, we discuss the mechanistic actions of metal oxide nanozymes along with their key characteristics which affect their enzymatic actions. Further, in this critical review, the recent progress towards the development of point-of-care (POC) diagnostic devices, cancer therapy, drug delivery, advanced antimicrobials/antibiofilm, dental caries, neurodegenerative diseases, and wound healing potential of metal oxide nanozymes is deliberated. The advantages of employing metal oxide nanozymes, their potential limitations in terms of nanotoxicity, and possible prospects for biomedical applications are also discussed with future recommendations.

Magnetic engineering nanoparticles: Versatile tools revolutionizing biomedical applications

The use of nanoparticles has increased significantly over the past few years in a number of fields, including diagnostics, biomedicine, environmental remediation, and water treatment, generating public interest. Among various types of nanoparticles, magnetic nanoparticles (MNPs) have emerged as an essential tool for biomedical applications due to their distinct physicochemical properties compared to other nanoparticles. This review article focuses on the recent growth of MNPs and comprehensively reviews the advantages, multifunctional approaches, biomedical applications, and latest research on MNPs employed in various biomedical techniques. Biomedical applications of MNPs hold on to their ability to rapidly switch magnetic states under an external field at room temperature. Ideally, these MNPs should be highly susceptible to magnetization when the field is applied and then lose that magnetization just as quickly once the field is removed. This unique property allows MNPs to generate heat when exposed to high-frequency magnetic fields, making them valuable tools in developing treatments for hyperthermia and other heat-related illnesses. This review underscores the role of MNPs as tools that hold immense promise in transforming various aspects of healthcare, from diagnostics and imaging to therapeutic treatments, with discussion on a wide range of peer-reviewed articles published on the subject. At the conclusion of this work, challenges and potential future advances of MNPs in the biomedical field are highlighted.

pH-Responsive Sorafenib/Iron-Co-Loaded Mesoporous Polydopamine Nanoparticles for Synergistic Ferroptosis and Photothermal Therapy

Ferroptosis has attracted significant attention as a new mechanism of cell death. Sorafenib (SRF) is widely considered a prototypical ferroptosis-inducing drug, particularly for liver cancer treatment. However, the low solubility and hydrophobic nature of SRF, along with the absence of synergistic therapeutic strategies, still limit its application in cancer treatment. Herein, we report a dual therapeutic method incorporating photothermal therapy and ferroptosis by using Fe-doped mesoporous polydopamine nanoparticles (Fe-mPDA@SRF-TPP) as a carrier for loading SRF and targeting triphenylphosphine (TPP). SRF molecules are efficiently encapsulated within the polydopamine nanospheres with a high loading ratio (80%) attributed to the porosity of Fe-mPDA, and the inherent biocompatibility and hydrophilicity of Fe-mPDA@SRF-TPP facilitate the transport of SRF to the target cancer cells. Under the external stimuli of acidic environment (pH 5.0), glutathione (GSH), and laser irradiation, Fe-mPDA@SRF-TPP shows sustained release of SRF and Fe ions with the ratio of 72 and 50% within 48 h. Fe-mPDA@SRF-TPP nanoparticles induce intracellular GSH depletion, inhibit glutathione peroxidase 4 (GPX4) activity, and generate hydroxyl radicals, all of which are essential components of the therapeutic ferroptosis process for killing MDA-MB-231 cancer cells. Additionally, the excellent near-infrared (NIR) light absorption of Fe-mPDA@SRF-TPP nanoparticles demonstrates their capability for photothermal therapy and further enhances the therapeutic efficiency. Therefore, this nanosystem provides a multifunctional therapeutic platform that overcomes the therapeutic limitations associated with standalone ferroptosis and enhances the therapeutic efficacy of SRF for breast cancer.

An ultrasound-controllable ROS-responsive nanoplatform for O2 and NO generation to enhance sonodynamic therapy against multidrug-resistant bacterial infections

Antimicrobial sonodynamic therapy (SDT) has broad application potential in the eradication of multidrug-resistant (MDR) bacterial infections due to its non-invasiveness, absence of resistance concern, and high cytotoxicity. However, the hypoxic infection microenvironment and the rapid depletion of O2 during SDT severely limit the therapeutic efficacy of SDT. Herein, an ultrasound-controllable ROS-responsive nanoplatform (FOT/Fe3O4@Lipo-ICG) was constructed and prepared by encapsulating FOT and Fe3O4 nanoparticles (Fe3O4 NPs) within sonosensitiser ICG-modified liposomes. Both in vitro and in vivo, we observed that ICG conjugation on the surface of liposomes could effectively maintain good dispersion and prevent ICG aggregates in complex biological matrices. In addition, liposomes could significantly block the catalytic activity of Fe3O4 NPs, as well as the release of FOT, whereas upon US irradiation, the catalytic activity of Fe3O4 NPs was recovered to catalyse the decomposition of endogenous H2O2 into O2 and ˙OH. Meanwhile, the FOT was successfully released to react with endogenous glutathione to sequentially produce NO. Based on the aforementioned advantages, the FOT/Fe3O4@Lipo-ICG demonstrated potent efficacy in eradicating methicillin-resistant Staphylococcus aureus-induced local infection and sepsis resulting from local infection. Thus, the developed US-controllable nanoplatform offers a promising strategy for enhancing SDT for eradicating MDR bacterial infections.

Research progress in nucleus-targeted tumor therapy

The nucleus is considered the most important organelle in the cell as it plays a central role in controlling cell reproduction, metabolism, and the cell cycle. The successful delivery of drugs into the nucleus can achieve excellent therapeutic effects, which reveals the potential of nucleus-targeted therapy in precision medicine. However, the transportation of therapeutics into the nucleus remains a significant challenge due to various biological barriers. Herein, we summarize the recent progress in the nucleus-targeted drug delivery system (NDDS). The structures of the nucleus and nuclear envelope are first described in order to understand the mechanisms by which drugs cross the nuclear envelope. Then, various drug delivery strategies based on the mechanisms and their applications are discussed. Finally, the challenges and solutions in the field of nucleus-targeted drug delivery are raised for developing a more efficient NDDS and promoting its clinical transformation.

Nanomedicine in cancer therapy

Cancer remains a highly lethal disease in the world. Currently, either conventional cancer therapies or modern immunotherapies are non-tumor-targeted therapeutic approaches that cannot accurately distinguish malignant cells from healthy ones, giving rise to multiple undesired side effects. Recent advances in nanotechnology, accompanied by our growing understanding of cancer biology and nano-bio interactions, have led to the development of a series of nanocarriers, which aim to improve the therapeutic efficacy while reducing off-target toxicity of the encapsulated anticancer agents through tumor tissue-, cell-, or organelle-specific targeting. However, the vast majority of nanocarriers do not possess hierarchical targeting capability, and their therapeutic indices are often compromised by either poor tumor accumulation, inefficient cellular internalization, or inaccurate subcellular localization. This Review outlines current and prospective strategies in the design of tumor tissue-, cell-, and organelle-targeted cancer nanomedicines, and highlights the latest progress in hierarchical targeting technologies that can dynamically integrate these three different stages of static tumor targeting to maximize therapeutic outcomes. Finally, we briefly discuss the current challenges and future opportunities for the clinical translation of cancer nanomedicines.

Identification of nanoparticles as vesicular cargo via Airy scanning fluorescence microscopy and spatial statistics

Many biomedical applications of nanoparticles on the cellular level require a characterisation of their subcellular distribution. Depending on the nanoparticle and its preferred intracellular compartment, this may be a nontrivial task, and consequently, the available methodologies are constantly increasing. Here, we show that super-resolution microscopy in combination with spatial statistics (SMSS), comprising the pair correlation and the nearest neighbour function, is a powerful tool to identify spatial correlations between nanoparticles and moving vesicles. Furthermore, various types of motion like for example diffusive, active or Lévy flight transport can be distinguished within this concept via suitable statistical functions, which also contain information about the factors limiting the motion, as well as regarding characteristic length scales. The SMSS concept fills a methodological gap related to mobile intracellular nanoparticle hosts and its extension to further scenarios is straightforward. It is exemplified on MCF-7 cells after exposure to carbon nanodots, demonstrating that these particles are stored predominantly in the lysosomes.

Multifunctional Liposomes Remodeling Tumor Immune Microenvironment for Tumor Chemoimmunotherapy

In the treatment of solid tumors, the complex barriers composed of cancer-associated fibroblasts (CAFs) prevent drug delivery and T cells infiltration into tumor tissues. Although nanocarriers hold great prospects in drug delivery, fibrosis causes the biological barrier and immunosuppressive tumor microenvironment (ITM) that impairs the anti-tumor efficacy of nanocarriers. Here, a small dendritic macromolecule loaded with doxorubicin (PAMAM-ss-DOX) (DP) is synthesized and encapsulated into pH-responsive nanoliposome, together with adjuvant toll-like receptor 7/8 (TLR7/8) agonist resiquimod (R848) and losartan (LOS). The pH-responsive liposome facilitates the simultaneous and effective delivery of DP, R848, and LOS, which can decompose and release these drugs under the acidic tumor microenvironment. The small sized DP (≈25 nm) with the ability to penetrate into tumor tissue and immunogenic cell death (ICD) can reverse the ITM and elicit immune response, which is equivalent to the effect of an in situ vaccine. Moreover, LOS reduces the activity of CAFs effectively, which can contribute to the infiltration of T cells. Therefore, this nano-platform provides a new therapeutic strategy for enhanced chemo-immunotherapy.

Lipid-functionalized gold nanorods with plug-to-direct mitochondria targeting ligand for synergetic photothermal-chemotherapy of tumor therapy

Mitochondria targeting therapeutic strategies are promising for more effective and precise cancer therapy. Photothermal therapy are extensively studied as noninvasive cancer treatment. With regards to all-in-one nanocarrier-mediated drug delivery platform, it is still a challenge to enhance one of the features but not compromise other merits. Herein, we present a mitochondrial targeting photothermal-chemotherapy all-in-one nanoplatform involving lipid-functionalized gold nanorods (AuNR) with plug-to-direct mitochondria targeting ligand for synergetic enhanced tumor therapy. Firstly, AuNR were modified by DSPE-PEG-SH owing to the special affinity of sulfhydryl group and gold. And then, DSPE-PEG-DOX with mitochondrial targeting character was directly inserted into DSPE-PEG-SH layer. Meanwhile, paclitaxel (PTX) was loaded in hydrophobic region of the lipid layer. Quite different from introducing additional mitochondrial targeting molecules, we incorporated amphiphilic DSPE-PEG-DOX into a DSPE-PEG-SH layer modified around AuNR to achieve both mitochondrial targeting, photothermal and dual drug loading in a simple AuNR-lipid-DOX/PTX platform, in the case that efficiently enhanced production of reactive oxygen species (ROS) in mitochondria and excellent anti-tumor efficacy were achieved. With good biocompatibility, the constructed nanoplatform based on lipid-functionalized AuNR synergistically combined mitochondrial targeted DSPE-PEG-DOX with mitochondrial-acted PTX and photothermal therapy (PTT), which provided a feasible strategy for organelle-targeted combination PTT-chemotherapy to improve therapeutic effects.

Bio-inspired Oxidative Stress Amplifier for Suppressing Cancer Metastasis and Imaging-Guided Combination Therapy

Antioxidant-defense systems of tumor cells protect them from oxidative damage and is strongly associated with tumor metastasis. In this work, a mussel-inspired multifunctional nanomedicine (ZS-MB@P) has been designed for inhibiting tumor growth and metastasis through amplified oxidative stress and photothermal/magnetothermal/photodynamic triple-combination therapy. This nanomedicine was fabricated via loading a silica shell on the magnetic nano-octahedrons [zinc-doped magnetic Fe₃O₄ nano-octahedrons] by encapsulating photosensitizer methylene blue (MB) and subsequently coating polydopamine (PDA) shells as "gatekeeper." The nanomedicine could realize photothermal therapy, photodynamic therapy, and magnetic hyperthermia after treatment with near-infrared (NIR) irradiation and applied magnetic field. Under pH and NIR stimulation, controlled amount of MB was released to produced exogenous reactive oxygen species. Noteworthy, PDA can amplify intracellular oxidative stress by depleting glutathione, thus inhibiting breast cancer metastasis effectively since oxidative stress is an important barrier to tumor metastasis. The outstanding ability to suppress tumor growth and metastasis was comprehensively assessed and validated both in vitro and in vivo. Moreover, the nanomedicine showed outstanding T₂ magnetic resonance imaging for tracking the treatment process. Taken together, this work offers an innovative approach in the synergistic treatment of recalcitrant breast cancer.

Mitochondrial dysfunction-targeted nanosystems for precise tumor therapeutics

Mitochondria play critical roles in the regulation of the proliferation and apoptosis of cancerous cells. Targeted induction of mitochondrial dysfunction in cancer cells by multifunctional nanosystems for cancer treatment has attracted increasing attention in the past few years. Numerous therapeutic nanosystems have been designed for precise tumor therapy by inducing mitochondrial dysfunction, including reducing adenosine triphosphate, breaking redox homeostasis, inhibiting glycolysis, regulating proteins, membrane potential depolarization, mtDNA damage, mitophagy dysregulation and so on. Understanding the mechanisms of mitochondrial dysfunction would be helpful for efficient treatment of diseases and accelerating the translation of these therapeutic strategies into the clinic. Then, various strategies to construct mitochondria-targeted nanosystems and induce mitochondrial dysfunction are summarized, and the recent research progress regarding precise tumor therapeutics is highlighted. Finally, the major challenges and an outlook in this rapidly developing field are discussed. This review is expected to inspire further development of novel mitochondrial dysfunction-based strategies for precise treatments of cancer and other human diseases.

Chlorogenic Acid-Conjugated Nanoparticles Suppression of Platelet Activation and Disruption to Tumor Vascular Barriers for Enhancing Drug Penetration in Tumor

Hypercoagulation threatens the lives of cancer patients and cancer progression. Platelet overactivation attributes to the tumor-associated hypercoagulation and maintenance of the tumor endothelial integrity, leading to limited intratumoral perfusion of nanoagents into solid tumors in spite of the enhanced penetration and retention effect (EPR). Therefore, the clinical application of nanotherapeutics in solid cancer still faces great challenges. Herein, this work establishes platelet inhibiting nanoagents based on Fe^III -doped C₃ N₄ coloaded with the chemotherapy drug and the antiplatelet drug chlorogenic acid (CA), further opening tumor vascular endothelial junctions, thereby disrupting the tumor vascular endothelial integrity, and enhancing drug perfusion. Moreover, CA not only damages the cancer cells but also potentiates the cytotoxicity induced by the chemotherapy drug doxorubicin, synergistically ablating the tumor tissue. Further, the introduction of CA relieves the original causes of the hypercoagulable state such as tissue factor (TF), thrombin, and matrix metalloproteinases (MMPs) secreted by cancer cells. It is anticipated that the hypercoagulation- and platelet-inhibition strategy by integration of phenolic acid CA into chemotherapy provides insights into platelet inhibition-assisted theranostics based on nanomedicines.

Multifunctional Plasmon-Tunable Au Nanostars and Their Applications in Highly Efficient Photothermal Inactivation and Ultra-Sensitive SERS Detection

The development and application in different fields of multifunctional plasmonic nanoparticles (NPs) have always been research hotspots. Herein, multi-tip Au nanostars (NSs) with an anisotropic structure were fabricated for the photothermal therapy (PTT) of bacteria and surface-enhanced Raman scattering (SERS) detection of pollutants. The size and localized surface plasmon resonance (LSPR) characteristics of Au NSs were adjusted by varying Au seed additions. In addition, photothermal conversion performance of Au NSs with various Au seed additions was evaluated. Photothermal conversion efficiency of Au NSs with optimal Au seed additions (50 μL) was as high as 28.75% under 808 nm laser irradiation, and the heat generated was sufficient to kill Staphylococcus aureus (S. aureus). Importantly, Au NSs also exhibited excellent SERS activity for the 4-mercaptobenzoic acid (4-MBA) probe molecule, and the local electromagnetic field distribution of Au NSs was explored through finite-difference time-domain (FDTD) simulation. As verified by experiments, Au NSs' SERS substrate could achieve a highly sensitive detection of a low concentration of potentially toxic pollutants such as methylene blue (MB) and bilirubin (BR). This work demonstrates a promising multifunctional nanoplatform with great potential for efficient photothermal inactivation and ultra-sensitive SERS detection.

Numerical simulation of superparamagnetic nanoparticle motion in blood vessels for magnetic drug delivery

A numerical model is developed for the motion of superparamagnetic nanoparticles in a non-Newtonian blood flow under the influence of a magnetic field. The rheological properties of blood are modeled by the Carreau flow and viscosity, and the stochastic effects of Brownian motion and red blood cell collisions are considered. The model is validated with existing data and good agreement with experimental results is shown. The effectiveness of magnetic drug delivery in various blood vessels is assessed and found to be most successful in arterioles and capillaries. A range of magnetic field strengths are modeled using equations for both a bar magnet and a point dipole: it is shown that the bar magnet is effective at capturing nanoparticles in limited cases, while the point dipole is highly effective across a range of conditions. A parameter study is conducted to show the effects of changing the dipole moment, the distance from the magnet to the blood vessel, and the initial release point of the nanoparticles. The distance from the magnet to the blood vessel is shown to play a significant role in determining nanoparticle capture rate. The optimal initial release position is found to be located within the tumor radius in capillaries and arterioles to prevent rapid diffusion to the edges of the blood vessel prior to arriving at the tumor and near the edge of the magnet when a bar magnet is used.

Design and application of DNA nanostructures for organelle-targeted delivery of anticancer drugs

INTRODUCTION

DNA nanostructures targeting organelles are of great significance for the early diagnosis and precise therapy of human cancers. This review is expected to promote the development of DNA nanostructure-based cancer treatment with organelle-level precision in the future.

AREAS COVERED

In this review, we introduce the different principles for targeting organelles, summarize the progresses in the development of organelle-targeting DNA nanostructures, highlight their advantages and applications in disease treatment, and discuss current challenges and future prospects.

EXPERT OPINION

Accurate targeting is a basic problem for effective cancer treatment. However, current DNA nanostructures cannot meet the actual needs. Targeting specific organelles is expected to further improve the therapeutic effect and overcome tumor cell resistance, thereby holding great practical significance for tumor treatment in the clinic. With the deepening of the research on the molecular mechanism of disease development, especially on tumorigenesis and tumor progression, and increasing understanding of the behavior of biological materials in living cells, more versatile DNA nanostructures will be constructed to target subcellular organelles for drug delivery, essentially promoting the early diagnosis of cancers, classification, precise therapy and the estimation of prognosis in the future.

Micro/Nanosystems for Magnetic Targeted Delivery of Bioagents

Targeted delivery of pharmaceuticals is promising for efficient disease treatment and reduction in adverse effects. Nano or microstructured magnetic materials with strong magnetic momentum can be noninvasively controlled via magnetic forces within living beings. These magnetic carriers open perspectives in controlling the delivery of different types of bioagents in humans, including small molecules, nucleic acids, and cells. In the present review, we describe different types of magnetic carriers that can serve as drug delivery platforms, and we show different ways to apply them to magnetic targeted delivery of bioagents. We discuss the magnetic guidance of nano/microsystems or labeled cells upon injection into the systemic circulation or in the tissue; we then highlight emergent applications in tissue engineering, and finally, we show how magnetic targeting can integrate with imaging technologies that serve to assist drug delivery.

Shape‐Mediated Magnetocrystalline Anisotropy and Relaxation Controls by Cobalt Ferrite Core–Shell Heterostructures for Magnetothermal Penetration Delivery

Simultaneous delivery of therapeutic agents and energy by magnetic nanoparticles (MNPs) at targeted sites can boost cancer therapy and alleviate side effects. To achieve this goal, however, the magnetic fluid hyperthermia (MFH) usually exhibits the unsufficient thermal efficiency due to their narrow magnetization curves. Besides, an inappropriately large administration concentration also causes health deterioration as shown in an animal model. In this study, the core–shell cube that enhances the coercivity and magnetization related to single‐compositional MNPs by elaborately tuning their interface relaxation via the magnetocrystalline and surface anisotropy is developed. Néel and Brownian relaxation can be adjusted by the particles’ structures to maximize the hyperthermia efficacy upon an alternating‐magnetic‐field (AMF). Furthermore, temozolomide and lactoferrin‐coated CoFe2O4@Fe3O4 core–shell cubes are rapidly internalized by targeting cancer cells and penetrate into tumor spheroids while subjecting to AMF. The targeted cubes with the capabilities of enhanced coercivity, AMF‐induced drug penetration into tumors, and magnetothermal ablation for cancer therapy display potentials for clinical uses.

Depleting Tumor Infiltrating B Cells to Boost Antitumor Immunity with Tumor Immune-Microenvironment Reshaped Hybrid Nanocage

Tumor infiltrating B cells (TIBs)-dependent immunotherapy has emerged as a promising method for tumor treatment. Depleting TIBs to boost antitumor immunity is a highly desirable yet challenging approach to TIBs-dependent immunotherapy. Herein, a tumor immune-microenvironment reshaped hybrid nanocage CPN-NLI/MLD coloaded with the Bruton's tyrosine kinase inhibitor ibrutinib, and cytotoxic drug docetaxel was developed for stepwise targeting TIBs and tumor cells, respectively. The tumor microenvironment responsive CPN-NLI/MLD promoted charge reversal and size reduction under acidic conditions (pH < 6.5). The accumulation of CPN-NLI/MLD in tumor tissues was achieved through CD13 targeting, and cellular uptake was increased due to the differ-targeting delivery. Targeting of docetaxel to tumor cells was achieved by the interaction of α-MSH modified on inner docetaxel-particle MLD and melanocortin-1 receptor on the surface of tumor cells. Targeting of ibrutinib to TIBs was achieved by the interaction of Neu5Ac modified on inner ibrutinib-particle NLI and CD22 on the surface of TIBs. The boosted antitumor immunity was achieved mainly by the inhibition of Bruton's tyrosine kinase activation mediated by ibrutinib, which reduced the proportion of TIBs, enhanced infiltration of CD8⁺ and CD4⁺ T cells, increased the secretion of immunogenic cytokines including IL-2 and IFN-γ, and inhibited the proliferation of regulatory T cells and secretion of immunosuppressive cytokines including IL-10, IL-4, and TGF-β. Furthermore, CPN-NLI/MLD improved the antitumor efficiency of chemoimmunotherapy by reshaping tumor immune-microenvironment by TIBs depletion. Taken together, CPN-NLI/MLD represents a promising method for effective tumor treatment and combination therapy by TIBs-dependent immunotherapy.

Multifunctional liposome for photoacoustic/ultrasound imaging-guided chemo/photothermal retinoblastoma therapy

Retinoblastoma (RB) is a malignant intraocular neoplasm that occurs in children. Diagnosis and therapy are frequently delayed, often leading to metastasis, which necessitates effective imaging and treatment. In recent years, the use of nanoplatforms allowing both imaging and targeted treatment has attracted much attention. Herein, we report a novel nanoplatform folate-receptor (FR) targeted laser-activatable liposome termed FA-DOX-ICG-PFP@Lip, which is loaded with doxorubicin (DOX)/indocyanine green (ICG) and liquid perfluoropentane (PFP) for photoacoustic/ultrasound (PA/US) dual-modal imaging-guided chemo/photothermal RB therapy. The dual-modal imaging capability, photothermal conversion under laser irradiation, biocompatibility, and antitumor ability of these liposomes were appraised. The multifunctional liposome showed a good tumor targeting ability and was efficacious as a dual-modality contrast agent both in vivo and in vitro. When laser-irradiated, the liposome converted light energy to heat. This action caused immediate destruction of tumor cells, while simultaneously initiating PFP phase transformation to release DOX, resulting in both photothermal and chemotherapeutic antitumor effects. Notably, the FA-DOX-ICG-PFP@Lip showed good biocompatibility and no systemic toxicity was observed after laser irradiation in RB tumor-bearing mice. Hence, the FA-DOX-ICG-PFP@Lip shows great promise for dual-modal imaging-guided chemo/photothermal therapy, and may have significant value for diagnosing and treating RB.

Advanced applications of cerium oxide based nanozymes in cancer

Cerium oxide nanozymes have emerged as a new type of bio-antioxidants in recent years. CeO2 nanozymes possess enzyme mimetic activities with outstanding free radical scavenging activity, facile synthesis conditions, and excellent biocompatibility. Based on these extraordinary properties, use of CeO2 nanozymes has been demonstrated to be a highly versatile therapeutic method for many diseases, such as for inflammation, rheumatoid arthritis, hepatic ischemia-reperfusion injury and Alzheimer's disease. In addition to that, CeO2 nanozymes have been widely used in the diagnosis and treatment of cancer. Many examples can be found in the literature, such as magnetic resonance detection, tumour marker detection, chemotherapy, radiotherapy, photodynamic therapy (PDT), and photothermal therapy (PTT). This review systematically summarises the latest applications of CeO2-based nanozymes in cancer research and treatment. We believe that this paper will help develop value-added CeO2 nanozymes, offering great potential in the biotechnology industry and with great significance for the diagnosis and treatment of a wide range of malignancies.

Development of nanotechnology-mediated precision radiotherapy for anti-metastasis and radioprotection

Radiotherapy (RT), including external beam RT and internal radiation therapy, uses high-energy ionizing radiation to kill tumor cells.

Tumor Microenvironment Activated Nanoenzyme-based Agents for Enhanced MRI-Guided Photothermal Therapy in NIR-II Window

We report a nanoenzyme-based photothermal agent, in which the nanoenzyme acts as a peroxidase, prodrug carrier, and MRI contrast agent. The formation of dimer by the prodrug under the catalysis...

Mito-Bomb: Targeting Mitochondria for Cancer Therapy

Cancer has been one of the most common life-threatening diseases for a long time. Traditional cancer therapies such as surgery, chemotherapy (CT), and radiotherapy (RT) have limited effects due to drug resistance, unsatisfactory treatment efficiency, and side effects. In recent years, photodynamic therapy (PDT), photothermal therapy (PTT), and chemodynamic therapy (CDT) have been utilized for cancer treatment owing to their high selectivity, minor resistance, and minimal toxicity. Accumulating evidence has demonstrated that selective delivery of drugs to specific subcellular organelles can significantly enhance the efficiency of cancer therapy. Mitochondria-targeting therapeutic strategies are promising for cancer therapy, which is attributed to the essential role of mitochondria in the regulation of cancer cell apoptosis, metabolism, and more vulnerable to hyperthermia and oxidative damage. Herein, the rational design, functionalization, and applications of diverse mitochondria-targeting units, involving organic phosphine/sulfur salts, quaternary ammonium (QA) salts, peptides, transition-metal complexes, guanidinium or bisguanidinium, as well as mitochondria-targeting cancer therapies including PDT, PTT, CDT, and others are summarized. This review aims to furnish researchers with deep insights and hints in the design and applications of novel mitochondria-targeting agents for cancer therapy.

Magnetic Nanoparticles for Biomedical Applications: From the Soul of the Earth to the Deep History of Ourselves

Precisely engineered magnetic nanoparticles (MNPs) have been widely explored for applications including theragnostic platforms, drug delivery systems, biomaterial/device coatings, tissue engineering scaffolds, performance-enhanced therapeutic alternatives, and even in SARS-CoV-2 detection strips. Such popularity is due to their unique, challenging, and tailorable physicochemical/magnetic properties. Given the wide biomedical-related potential applications of MNPs, significant achievements have been reached and published (exponentially) in the last five years, both in synthesis and application tailoring. Within this review, and in addition to essential works in this field, we have focused on the latest representative reports regarding the biomedical use of MNPs including characteristics related to their oriented synthesis, tailored geometry, and designed multibiofunctionality. Further, actual trends, needs, and limitations of magnetic-based nanostructures for biomedical applications will also be discussed.

Designer exosomes enabling tumor targeted efficient chemo/gene/photothermal therapy

Exosomes, endogenous nanosized particles (50-150 nm) secreted and absorbed by cells, have been recently used as diagnostic and therapeutic platforms in cancer treatment. The integration of exosome-based delivery with multiple therapeutic modalities could result in better clinical outcomes and reduced-sided effects. Here, we combined the targeting and biocompatibility of designer exosomes with chemo/gene/photothermal therapy. Our platform consists of exosomes loaded with internalized doxorubicin (DOX, a model cancer drug) and coated with magnetic nanoparticles conjugated with molecular beacons capable of targeting miR-21 for responsive molecular imaging. The coated magnetic nanoparticle enables enrichment of the exosomes at the tumor site by external magnetic field guidance. After the exosomes are gathered at the tumor site, the application of near-infrared radiation (NIR) induces localized hyperthermia and triggers the release of cargoes loaded inside the exosome. The released molecular beacon can target the miR-21 for both imaging and gene silencing. Meanwhile, the released doxorubicin serves to kill the cancer cells. About 91.04 % of cancer cells are killed after treatment with Exo-DOX-Fe₃O₄@PDA-MB under NIR. The ability of the exosome-based method for cancer therapy has been demonstrated by animal models, in which the tumor size is reduced dramatically by 97.57 % with a magnetic field-guided tumor-targeted chemo/gene/photothermal approach. Thus, we expected this designer exosome-mediated multi-mode therapy to be a promising platform for the next-generation precision cancer nanomedicines.

Smart Stimuli-Responsive and Mitochondria Targeting Delivery in Cancer Therapy

Dysfunction in the mitochondria (Mc) contributes to tumor progression. It is a major challenge to deliver therapeutic agents specifically to the Mc for precise treatment. Smart drug delivery systems are based on stimuli-responsiveness and active targeting. Here, we give a whole list of documented pathways to achieve smart stimuli-responsive (St-) and Mc-targeted DDSs (St-Mc-DDSs) by combining St and Mc targeting strategies. We present the formulations, targeting characteristics of St-Mc-DDSs and clarify their anti-cancer mechanisms as well as improvement in efficacy and safety. St-Mc-DDSs usually not only have Mc-targeting groups, molecules (lipophilic cations, peptides, and aptamers) or materials but also sense the surrounding environment and correspondingly respond to internal biostimulators such as pH, redox changes, enzyme and glucose, and/or externally applied triggers such as light, magnet, temperature and ultrasound. St-Mc-DDSs exquisitely control the action site, increase therapeutic efficacy and decrease side effects of the drug. We summarize the clinical research progress and propose suggestions for follow-up research. St-Mc-DDSs may be an innovative and sensitive precision medicine for cancer treatment.

Recent progress in nanomedicine for enhanced cancer chemotherapy

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

Phenolic-enabled nanotechnology: versatile particle engineering for biomedicine

Phenolics are ubiquitous in nature and have gained immense research attention because of their unique physiochemical properties and widespread industrial use. In recent decades, their accessibility, versatile reactivity, and relative biocompatibility have catalysed research in phenolic-enabled nanotechnology (PEN) particularly for biomedical applications which have been a major benefactor of this emergence, as largely demonstrated by polydopamine and polyphenols. Therefore, it is imperative to overveiw the fundamental mechanisms and synthetic strategies of PEN for state-of-the-art biomedical applications and provide a timely and comprehensive summary. In this review, we will focus on the principles and strategies involved in PEN and summarize the use of the PEN synthetic toolkit for particle engineering and the bottom-up synthesis of nanohybrid materials. Specifically, we will discuss the attractive forces between phenolics and complementary structural motifs in confined particle systems to synthesize high-quality products with controllable size, shape, composition, as well as surface chemistry and function. Additionally, phenolic's numerous applications in biosensing, bioimaging, and disease treatment will be highlighted. This review aims to provide guidelines for new scientists in the field and serve as an up-to-date compilation of what has been achieved in this area, while offering expert perspectives on PEN's use in translational research.

Mitochondria-Specific Agents for Photodynamic Cancer Therapy: A Key Determinant to Boost the Efficacy

Mitochondria-targeted photodynamic therapy (Mt-PDT), which enables the photogenerated cytotoxic oxygen species with fatal oxidative damage to block mitochondrial functions, has been considered as a promising method to enhance the anticancer effectiveness. Aiming at the challenges of PDT, in the past few decades, numerous mitochondria-targeting molecular agents have been developed to boost the PDT efficacy via directly destroying the mitochondria or activating mitochondria-mediated cell death pathways. Herein, a review for recent advances of Mt-PDT is highlighted including: mitochondrial targeting design principles and strategies, therapeutic performance of mitochondria-targeted agents-mediated PDT as well as the agent-free Mt-PDT. In addition, it puts together the achievements of the combinatory mitochondria-anchoring PDT and other anticancer strategies, demonstrating the advantages provided by Mt-PDT. The existing challenges are discussed and future settlements for the development of mitochondria-specific agents are also forecasted.

Portfolio Targeting Strategy To Realize the Assembly and Membrane Fusion-Mediated Delivery of Gold Nanoparticles to Mitochondria for Enhanced NIR Photothermal Therapies

Targeting mitochondria has always been a challenging goal for therapeutic nanoparticle agents due to their heterotypic features and size, which usually lead to a lysosome/endosome endocytosis pathway. To overcome this limitation, in this work, a portfolio targeting strategy combining a small targeting molecule with a biomembrane was developed. Modification of small targeting molecule H₂N-TPP on gold nanoparticles (GNPs) could not only facilitate the mitochondrial targeting but could also induce gold nanoparticle assembly. Therefore, the GNPs were endowed with good absorption and photothermal conversion abilities in the near-infrared (NIR) region. Meanwhile, a biomimetic strategy was adopted by wrapping the gold nanoparticle assembly (GNA) with cancer cell membranes (CCMs), which helped the GNA enter the prostatic cancer cell via a homotypic membrane-fusion process to avoid being trapped in endosomes/lysosomes. Thereafter, the GNA remaining in the cytoplasm could reach mitochondria more efficiently via guidance from H₂N-TPP molecules. This "biomembrane-small molecule" combination targeting process was evidenced by fluorescence microscopy, and the highly efficient photothermal ablation of prostatic tumors in vivo was demonstrated. This portfolio targeting strategy could be extended to various nanodrugs/agents to realize an accurate subcellular targeting efficiency for cancer treatments or cell detections.

A Biomimetic Polymer Magnetic Nanocarrier Polarizing Tumor-Associated Macrophages for Potentiating Immunotherapy

The progress of antitumor immunotherapy is usually limited by tumor-associated macrophages (TAMs) that account for the highest proportion of immunosuppressive cells in the tumor microenvironment, and the TAMs can also be reversed by modulating the M2-like phenotype. Herein, a biomimetic polymer magnetic nanocarrier is developed with selectively targeting and polarizing TAMs for potentiating immunotherapy of breast cancer. This nanocarrier PLGA-ION-R837 @ M (PIR @ M) is achieved, first, by the fabrication of magnetic polymer nanoparticles (NPs) encapsulating Fe₃ O₄ NPs and Toll-like receptor 7 (TLR7) agonist imiquimod (R837) and, second, by the coating of the lipopolysaccharide (LPS)- treated macrophage membranes on the surface of the NPs for targeting TAMs. The intracellular uptake of the PIR @ M can greatly polarize TAMs from M2 to antitumor M1 phenotype with the synergy of Fe₃ O₄ NPs and R837. The relevant mechanism of the polarization is deeply studied through analyzing the mRNA expression of the signaling pathways. Different from previous reports, the polarization is ascribed to the fact that Fe₃ O₄ NPs mainly activate the IRF5 signaling pathway via iron ions instead of the reactive oxygen species-induced NF-κB signaling pathway. The anticancer effect can be effectively enhanced through potentiating immunotherapy by the polarization of the TAMs in the combination of Fe₃ O₄ NPs and R837.

A novel progress of drug delivery system for organelle targeting in tumour cells

At present, malignant tumours have become one of the most serious diseases that endanger human health. According to a survey on causes of death in Chinese population in early 1990s, the malignant tumours were the second leading cause of death. In the treatment of tumours, the ideal situation is that drugs should target and accumulate at tumour sites and destroy tumour cells specifically, without affecting normal cells and stem cells with regenerative capacity. This requires drugs to be specifically transported to the target organs, tissues, cells, and even specific organelles, like mitochondria, nuclei, lysosomes, endoplasmic reticulum (ER), and Golgi apparatus (GA). The nano drug delivery system can not only protect drugs from degradation but also facilitate functional modification and targeted drug delivery to the tumour site. This article mainly reviews the targeting of nano drug delivery systems to tumour cytoplasmic matrix, nucleus, mitochondria, ER, and lysosomes. Organelle-specific drug delivery system will be a major mean of targeting drug delivery with lower toxicity, less dosage and higher drug concentration in tumour cells.

Dual-targeted photothermal agents for enhanced cancer therapy

Photothermal therapy, in which light is converted into heat and triggers local hyperthermia to ablate tumors, presents an inherently specific and noninvasive treatment for tumor tissues. In this area, the development of efficient photothermal agents (PTAs) has always been a central topic. Although many efforts have been made on the investigation of novel molecular architectures and photothermal materials over the past decades, PTAs can cause severe damage to normal tissues because of the poor tumor aggregate ability and high irradiation density. Recently, dual-targeted photothermal agents (DTPTAs) provide an attractive strategy to overcome these problems and enhance cancer therapy. DTPTAs are functionalized with two classes of targeting units, including tumor environment targeting sites, tumor targeting sites and organelle targeting sites. In this perspective, typical targeted ligands and representative examples of photothermal therapeutic agents with dual-targeted properties are systematically summarized and recent advances using DTPTAs in tumor therapy are highlighted.

Aza-BODIPY-Based Nanomedicines in Cancer Phototheranostics

Cancer phototheranostics, composed of optical diagnosis and phototherapy (including photodynamic therapy and photothermal therapy), is a promising strategy for precise tumor treatment. Due to the unique properties of near-infrared absorption/emission, high reactive oxygen species generation, and photothermal conversion efficiency, aza-boron-dipyrromethene (aza-BODIPY), as an emerging organic photosensitizer, has shown great potential for tumor phototheranostics. By encapsulating aza-BODIPY photosensitizers within functional amphiphilic polymers, we can afford hydrophilic nanomedicines that selectively target tumor sites via an enhanced permeability and retention effect, thereby efficiently improving diagnosis and therapeutic efficacy. Herein, in this spotlight article, we attempt to highlight our recent contributions in the development of aza-BODIPY-based nanomedicines, which comprises three main sections: (1) to elucidate the design strategy of aza-BODIPY photosensitizers and corresponding nanomedicines; (2) to overview their photophysical properties and biomedical applications in phototheranostics, including fluorescence imaging, photoacoustic imaging, photodynamic therapy, photothermal therapy, and synergistic therapy; and (3) to depict the challenges and future perspectives of aza-BODIPY nanomedicines. It is believed that this Spotlight on Applications article would illuminate the way of developing new aza-BODIPY nanomedicines as well as other organic photosensitizer-based nanomedicines for future clinical translation.

ATP Suppression by pH-Activated Mitochondria-Targeted Delivery of Nitric Oxide Nanoplatform for Drug Resistance Reversal and Metastasis Inhibition

Mitochondria, which are important mediators for cancer initiation, growth, metastasis, and drug resistance, have been considered as a major target in cancer therapy. Herein, an acid-activated mitochondria-targeted drug nanocarrier is constructed for precise delivery of nitric oxide (NO) as an adenosine triphosphate (ATP) suppressor to amplify the therapeutic efficacy in cancer treatments. By combining α-cyclodextrin (α-CD) and acid-cleavable dimethylmaleic anhydride modified PEG conjugated mitochondria-targeting peptide, the nanocarrier shows prolonged blood circulation time and enhanced cellular uptake together with selectively restoring mitochondria-targeting capability under tumor extracellular pH (6.5). Such specific mitochondria-targeted delivery of NO proves crucial in inducing mitochondria dysfunction through facilitating mitochondrial membrane permeabilization and downregulating ATP level, which can inhibit P-glycoprotein-related bioactivities and formation of tumor-derived microvesicles to combat drug resistance and cancer metastasis. Therefore, this pioneering acid-activated mitochondria-targeted NO nanocarrier is supposed to be a malignant tumor opponent and may provide insights for diverse NO-relevant cancer treatments.

Ru@CeO2 yolk shell nanozymes: Oxygen supply in situ enhanced dual chemotherapy combined with photothermal therapy for orthotopic/subcutaneous colorectal cancer

Hypoxia is an important factor in forming multidrug resistance, recurrence and metastasis in solid tumors. Nanozymes respond to tumor microenvironment for tumor-specific treatment is a new and effective strategy. In this study, one-pot method was used to synthesize hollow Ru@CeO2 yolk shell nanozymes (Ru@CeO2 YSNs), which possess excellent light-to-heat conversion efficiency and catalytic performance. Antitumor drug ruthenium complex (RBT) and resveratrol (Res) were dual-loaded in Ru@CeO2 YSNs, and a double outer layer structure using polyethylene glycol was constructed to form dual-drug delivery system (Ru@CeO2-RBT/Res-DPEG) that was released on demand. The double outer layer structure increased the biocompatibility of Ru@CeO2 YSNs and effectively prolong the circulation time in blood. Ru@CeO2-RBT/Res-DPEG catalyzes endogenous H2O2 to produce oxygen, which achieve in situ oxygen supply and enhanced dual-chemotherapy and photothermal therapy (PTT) for colorectal cancer. In vitro studies found that Ru@CeO2-RBT/Res-DPEG has good tumor penetration depth and antitumor effect. In addition, Ru@CeO2-RBT/Res-DPEG can alleviate tumor hypoxia, and inhibit metastasis and recurrence of orthotopic and subcutaneous colorectal cancer. Accordingly, the study shows that yolk shell nanozymes can be used as an efficient synergistic system for dual-chemotherapy and PTT to kill tumor and inhibit orthotopic colorectal cancer metastasis and recurrence.

Multifunctional HNT@Fe3O4@PPy@DOX Nanoplatform for Effective Chemo-Photothermal Combination Therapy of Breast Cancer with MR Imaging

Multifunctional nanoparticles for imaging and treatment in cancer are getting more and more attention recently. Herein, halloysite nanotubes (HNTs), natural clay nanotubes, are designed as multifunctional nanoplatform for targeted delivering photothermal therapy agents and chemotherapeutic drugs. Fe₃O₄ was anchored on the outer surfaces of HNTs and then doxorubicin (DOX) was loaded on the nanotubes. Afterward, a layer of polypyrrole (PPy), as photothermal agent, was wrapped on the tubes. The nanoplatform of HNT@Fe₃O₄@PPy@DOX can be guided to tumor tissue by an external magnetic field, and then performs chemo-photothermal combined therapy by 808 nm laser irradiation. HNT@Fe₃O₄@PPy@DOX shows the ability of T₂-weighted magnetic resonance imaging, which could be considered as a promising application in magnetic targeting tumor therapy. In vitro and in vivo experiments demonstrate that HNTs nanoplatform has good biocompatibility and produces a strong antitumor effect trigged by near-infrared laser irradiation. The novel chemo-photothermal therapy nanoplatform based on HNTs may be developed as a multifunctional nanoparticle for imaging and therapy in breast cancer.

A Single Molecule Drug Targeting Photosensitizer for Enhanced Breast Cancer Photothermal Therapy

Targeting is one of the most important strategies for enhancing the efficacy of cancer photothermal therapy (PTT) and reducing damage to surrounding normal tissues. Compared with the traditional targeting approaches, the active targeting of breast cancer cells in PTT using chemotherapeutic drugs, such as tamoxifen (TAM), in combination with single-molecule photothermal photosensitizers has superior selectivity and therapeutic effects. However, single-molecule drug-targeting photosensitizers for improved PTT efficacy are not widely reported. Accordingly, herein, a near-infrared induced small-molecule photothermal photosensitizer (CyT) is developed that actively targets the estrogen receptors (ERs) of breast cancer cells as well as targets mitochondria by structure-inherent targeting. Cell uptake and cytotoxicity studies using different types of cells show that CyT enhances the efficiency of TAM-based PTT by targeting ER-overexpressing breast cancer cells and selectively killing them. In vivo experiments demonstrate that CyT can be used as a photothermal agent for fluorescence imaging-guided PTT. More importantly, the intravenous injection of CyT results in better targeting and efficiency of tumor inhibition compared with that achieved with the TAM-free control molecule Cy. Thus, the study presents an excellent small-molecule photothermal agent for breast cancer therapy with potential clinical application prospects.

Nanoparticles modified by polydopamine: Working as "drug" carriers

Inspired by the mechanism of mussel adhesion, polydopamine (PDA), a versatile polymer for surface modification has been discovered. Owing to its unique properties like extraordinary adhesiveness, excellent biocompatibility, mild synthesis requirements, as well as distinctive drug loading approach, strong photothermal conversion capacity and reactive oxygen species (ROS) scavenging facility, various PDA-modified nanoparticles have been desired as drug carriers. These nanoparticles with diverse nanostructures are exploited in multifunctions, consisting of targeting, imaging, chemical treatment (CT), photodynamic therapy (PDT), photothermal therapy (PTT), tissue regeneration ability, therefore have attracted great attentions in plenty biomedical applications. Herein, recent progress of PDA-modified nanoparticle drug carriers in cancer therapy, antibiosis, prevention of inflammation, theranostics, vaccine delivery and adjuvant, tissue repair and implant materials are reviewed, including preparation of PDA-modified nanoparticle drug carriers with various nanostructures and their drug loading strategies, basic roles of PDA surface modification, etc. The advantages of PDA modification in overcoming the existing limitations of cancer therapy, antibiosis, tissue repair and the developing trends in the future of PDA-modified nanoparticle drug carriers are also discussed.

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Multifunctional PDA-modified drug systems are introduced in terms of classification, synthesis and drug loading strategies.

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Basic roles of PDA surface modification in the drug systems are discussed.

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Biomedical applications and unique advantages of the PDA-modified nanoparticle working as drug carriers are illustrated.

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Challenges and perspectives for future development are proposed.

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

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

Amplified Photoacoustic Signal and Enhanced Photothermal Conversion of Polydopamine-Coated Gold Nanobipyramids for Phototheranostics and Synergistic Chemotherapy

Light-responsive nanoprobes were suffering from the threat of high-dose laser irradiation, and it was important for constructing new nanoprobes for safe and efficient phototheranostics. Here, polydopamine (PDA)-coated gold nanobipyramids (AuNBPs@PDA) were synthesized for amplified photoacoustic (PA) signal and enhanced photothermal conversion with low-dose laser irradiation and then doxorubicin (DOX)-loaded AuNBPs@PDA-DOX nanoprobes were constructed for PA imaging-guided synergistic photothermal therapy (PTT) and chemotherapy. The AuNBPs@PDA nanoparticles possessed higher photothermal conversion efficiency (42.07%) and stronger PA signal than those of AuNBP nanoparticles, and the AuNBPs@PDA-DOX nanoprobes showed dual-responsive DOX release of pH and photothermal stimulation. With low-dose laser irradiation (1.0 W/cm²) and low-concentration AuNBPs@PDA-DOX (60 μg/mL), the 4T1 cell viability was reduced to about 5%, owing to the combination of PTT and chemotherapy, compared with 42.3% of single chemotherapy and 25.3% of single PTT. Moreover, by modeling 4T1 tumor-bearing nude mice, in vivo PA imaging was achieved and the tumors were completely inhibited, demonstrating the excellent synergistic effect of PTT/chemotherapy. Therefore, the developed AuNBPs@PDA-DOX nanoprobes can be used for phototheranostics and synergistic chemotherapy, achieving low-dose laser irradiation and high-efficient visualized theranostics.

Mitochondria-Modulating Porous Se@SiO2 Nanoparticles Provide Resistance to Oxidative Injury in Airway Epithelial Cells: Implications for Acute Lung Injury

Background

Mitochondrial dysfunction played a vital role in the pathogenesis of various diseases, including acute lung injury (ALI). However, few strategies targeting mitochondria were developed in treating ALI. Recently, we fabricated a porous Se@SiO₂ nanoparticles (NPs) with antioxidant properties.

Methods

The protective effect of Se@SiO₂ NPs was assessed using confocal imaging, immunoblotting, RNA-seq, mitochondrial respiratory chain (MRC) activity assay, and transmission electron microscopy (TEM) in airway epithelial cell line (Beas-2B). The in vivo efficacy of Se@SiO₂ NPs was evaluated in a lipopolysaccharide (LPS)-induced ALI mouse model.

Results

This study demonstrated that Se@SiO₂ NPs significantly increased the resistance of airway epithelial cells under oxidative injury and shifted lipopolysaccharide-induced gene expression profile closer to the untreated controls. The cytoprotection of Se@SiO₂ was found to be achieved by maintaining mitochondrial function, activity, and dynamics. In an animal model of ALI, pretreated with the NPs improved mitochondrial dysfunction, thus reducing inflammatory responses and diffuse damage in lung tissues. Additionally, RNA-seq analysis provided evidence for the broad modulatory activity of our Se@SiO₂ NPs in various metabolic disorders and inflammatory diseases.

Conclusion

This study brought new insights into mitochondria-targeting bioactive NPs, with application potential in curing ALI or other human mitochondria-related disorders.