Traceable Bioinspired Nanoparticle for the Treatment of Metastatic Breast Cancer via NIR-Trigged Intracellular Delivery of Methylene Blue and Cisplatin

TREM2 scFv-Engineering Escherichia coli Displaying Modulation of Macrophages to Boost Cancer Radio-Immunotherapy

Preoperative neoadjuvant radio-chemotherapy is a cornerstone in the treatment of low rectal cancer, yet its effectiveness can be limited by the insensitivity of some patients, profoundly impacting their quality of life. Through preliminary research, it is found that TREM2+ macrophages play a pivotal role in the non-responsiveness to immunotherapy. To address this challenge, a novel ionizing radiation-responsive delivery system is developed for the precise expression of anti-TREM2 single-chain antibody fragments (scFv) using an engineered probiotic, Escherichia coli Nissle 1917 (EcN), to modulate immunotherapy. The released anti-TREM2 scFv can be precisely targeted and delivered to the tumor site via the engineered EcN outer membrane vesicles (OMVs), thereby reversing the immunosuppressive tumor microenvironment and enhancing tumor therapeutic efficiency when used in combination with the αPD-L1 immune checkpoint inhibitor. Additionally, these engineered bacteria can be further modified to enhance the intestinal colonization capabilities through oral administration, thereby regulating the gut microbiota and its metabolic byproducts. Consequently, the ionizing radiation-responsive drug delivery system based on the engineered bacteria not only introduces a promising new therapeutic option for low rectal cancer but also showcases the potential to finely tune immune responses within the intricate tumor microenvironment, paving the way for innovative strategies in tumor radio-immunotherapy.

Theranostic nanogels: multifunctional agents for simultaneous therapeutic delivery and diagnostic imaging

In recent years, there has been a growing interest in multifunctional theranostic agents capable of delivering therapeutic payloads while facilitating simultaneous diagnostic imaging of diseased sites. This approach offers a comprehensive strategy particularly valuable in dynamically evolving diseases like cancer, where combining therapy and diagnostics provides crucial insights for treatment planning. Nanoscale platforms, specifically nanogels, have emerged as promising candidates due to their stability, tunability, and multifunctionality as carriers. As a well-studied subgroup of soft polymeric nanoparticles, nanogels exhibit inherent advantages due to their size and chemical compositions, allowing for passive and active targeting of diseased tissues. Moreover, nanogels loaded with therapeutic and diagnostic agents can be designed to respond to specific stimuli at the disease site, enhancing their efficacy and specificity. This capability enables fine-tuning of theranostic platforms, garnering significant clinical interest as they can be tailored for personalized treatments. The ability to monitor tumor progression in response to treatment facilitates the adaptation of therapies according to individual patient responses, highlighting the importance of designing theranostic platforms to guide clinicians in making informed treatment decisions. Consequently, the integration of therapy and diagnostics using theranostic platforms continues to advance, offering intelligent solutions to address the challenges of complex diseases such as cancer. In this context, nanogels capable of delivering therapeutic payloads and simultaneously armed with diagnostic modalities have emerged as an attractive theranostic platform. This review focuses on advances made toward the fabrication and utilization of theranostic nanogels by highlighting examples from recent literature where their performances through a combination of therapeutic agents and imaging methods have been evaluated.

Potentiating Immunogenic Cell Death in Cold Tumor with Functional Living Materials of FeAu-Methylene Blue Composites

Low immunogenicity, absence of tumor-infiltrating lymphocytes and immunosuppressive microenvironment of immune cold tumors are the main bottlenecks leading to unfavorable prognosis. Here, an integrated tumor bioimaging and multimodal therapeutic strategy is developed, which converts immune cold into hot by modulating oxidative stress levels, enhancing photo-killing efficacy, inducing immunogenic cell death and inhibiting the immune checkpoint. On that occasion, the unique tumor microenvironment can be harnessed to biosynthesize in situ self-assembly iron complexes and fluorescent gold nanoclusters from metal ions Fe(II) and Au(III) for active targeting and real-time visualization of the tumors, simultaneously regulating reactive oxygen species levels within tumors via peroxidase-like activity. Furthermore, methylene blue (MB)-mediated photodynamic therapy promotes the release of damage-associated molecular patterns (DAMPs), which acts as in situ tumor vaccine and further induces dendritic cells maturation, augments the infiltration of antitumor T cells and significantly impedes the primary tumor growth and proliferation. More strikingly, by synergizing with the programmed cell death receptor-1 (PD-1) checkpoint inhibitor, the immunosuppressive microenvironment is remodeled and the survival time of model mice is prolonged. In summary, this paradigm utilizes the tumor-specific microenvironment to boost robust and durable systemic antitumor immunity, providing a novel opportunity for precision cancer theranostics.

T Cell and Natural Killer Cell Membrane-Camouflaged Nanoparticles for Cancer and Viral Therapies

Extensive research has been conducted on the application of nanoparticles in the treatment of cancer and infectious diseases. Due to their exceptional characteristics and flexible structure, they are classified as highly efficient drug delivery systems, ensuring both safety and targeted delivery. Nevertheless, nanoparticles still encounter obstacles, such as biological instability, absence of selectivity, recognition as unfamiliar elements, and quick elimination, which restrict their remedial capacity. To surmount these drawbacks, biomimetic nanotechnology has been developed that utilizes T cell and natural killer (NK) cell membrane-encased nanoparticles as sophisticated methods of administering drugs. These nanoparticles can extend the duration of drug circulation and avoid immune system clearance. During the membrane extraction and coating procedure, the surface proteins of immunological cells are transferred to the biomimetic nanoparticles. Such proteins present on the surface of cells confer several benefits to nanoparticles, including prolonged circulation, enhanced targeting, controlled release, specific cellular contact, and reduced in vivo toxicity. This review focuses on biomimetic nanosystems that are derived from the membranes of T cells and NK cells and their comprehensive extraction procedure, manufacture, and applications in cancer treatment and viral infections. Furthermore, potential applications, prospects, and existing challenges in their medical implementation are highlighted.

A Nanorobotics-Based Approach of Breast Cancer in the Nanotechnology Era

We are living in an era of advanced nanoscience and nanotechnology. Numerous nanomaterials, culminating in nanorobots, have demonstrated ingenious applications in biomedicine, including breast cancer (BC) nano-theranostics. To solve the complicated problem of BC heterogeneity, non-targeted drug distribution, invasive diagnostics or surgery, resistance to classic onco-therapies and real-time monitoring of tumors, nanorobots are designed to perform multiple tasks at a small scale, even at the organelles or molecular level. Over the last few years, most nanorobots have been bioengineered as biomimetic and biocompatible nano(bio)structures, resembling different organisms and cells, such as urchin, spider, octopus, fish, spermatozoon, flagellar bacterium or helicoidal cyanobacterium. In this review, readers will be able to deepen their knowledge of the structure, behavior and role of several types of nanorobots, among other nanomaterials, in BC theranostics. We summarized here the characteristics of many functionalized nanodevices designed to counteract the main neoplastic hallmark features of BC, from sustaining proliferation and evading anti-growth signaling and resisting programmed cell death to inducing angiogenesis, activating invasion and metastasis, preventing genomic instability, avoiding immune destruction and deregulating autophagy. Most of these nanorobots function as targeted and self-propelled smart nano-carriers or nano-drug delivery systems (nano-DDSs), enhancing the efficiency and safety of chemo-, radio- or photodynamic therapy, or the current imagistic techniques used in BC diagnosis. Most of these nanorobots have been tested in vitro, using various BC cell lines, as well as in vivo, mainly based on mice models. We are still waiting for nanorobots that are low-cost, as well as for a wider transition of these favorable effects from laboratory to clinical practice.

Recent Progress in Peptide-Based Molecular Probes for Disease Bioimaging

Recent strides in molecular pathology have unveiled distinctive alterations at the molecular level throughout the onset and progression of diseases. Enhancing the in vivo visualization of these biomarkers is crucial for advancing disease classification, staging, and treatment strategies. Peptide-based molecular probes (PMPs) have emerged as versatile tools due to their exceptional ability to discern these molecular changes with unparalleled specificity and precision. In this Perspective, we first summarize the methodologies for crafting innovative functional peptides, emphasizing recent advancements in both peptide library technologies and computer-assisted peptide design approaches. Furthermore, we offer an overview of the latest advances in PMPs within the realm of biological imaging, showcasing their varied applications in diagnostic and therapeutic modalities. We also briefly address current challenges and potential future directions in this dynamic field.

Biomimetic Nano-Drug Delivery System: An Emerging Platform for Promoting Tumor Treatment

With the development of nanotechnology, nanoparticles (NPs) have shown broad prospects as drug delivery vehicles. However, they exhibit certain limitations, including low biocompatibility, poor physiological stability, rapid clearance from the body, and nonspecific targeting, which have hampered their clinical application. Therefore, the development of novel drug delivery systems with improved biocompatibility and high target specificity remains a major challenge. In recent years, biofilm mediated biomimetic nano-drug delivery system (BNDDS) has become a research hotspot focus in the field of life sciences. This new biomimetic platform uses bio-nanotechnology to encapsulate synthetic NPswithin biomimetic membrane, organically integrating the low immunogenicity, low toxicity, high tumor targeting, good biocompatibility of the biofilm with the adjustability and versatility of the nanocarrier, and shows promising applications in the field of precision tumor therapy. In this review, we systematically summarize the new progress in BNDDS used for optimizing drug delivery, providing a theoretical reference for optimizing drug delivery and designing safe and efficient treatment strategies to improve tumor treatment outcomes.

Cellular Membrane Components-Mediated Cancer Immunotherapeutic Platforms

Immune cell engineering is an active field of ongoing research that can be easily applied to nanoscale biomedicine as an alternative to overcoming limitations of nanoparticles. Cell membrane coating and artificial nanovesicle technology have been reported as representative methods with an advantage of good biocompatibility for biomimetic replication of cell membrane characteristics. Cell membrane-mediated biomimetic technique provides properties of natural cell membrane and enables membrane-associated cellular/molecular signaling. Thus, coated nanoparitlces (NPs) and artificial nanovesicles can achieve effective and extended in vivo circulation, enabling execution of target functions. While coated NPs and artificial nanovesicles provide clear advantages, much work remains before clinical application. In this review, first a comprehensive overview of cell membrane coating techniques and artificial nanovesicles is provided. Next, the function and application of various immune cell membrane types are summarized.

Nanoparticle-Based Photothermal Therapy for Breast Cancer Noninvasive Treatment

Rapid advancements in materials science and nanotechnology, intertwined with oncology, have positioned photothermal therapy (PTT) as a promising noninvasive treatment strategy for cancer. The breast's superficial anatomical location and aesthetic significance render breast cancer a particularly pertinent candidate for the clinical application of PTT following melanoma. This review comprehensively explores the research conducted on the various types of nanoparticles employed in PTT for breast cancer and elaborates on their specific roles and mechanisms of action. The integration of PTT with existing clinical therapies for breast cancer is scrutinized, underscoring its potential for synergistic outcomes. Additionally, the mechanisms underlying PTT and consequential modifications to the tumor microenvironment after treatment are elaborated from a medical perspective. Future research directions are suggested, with an emphasis on the development of integrative platforms that combine multiple therapeutic approaches and the optimization of nanoparticle synthesis for enhanced treatment efficacy. The goal is to push the boundaries of PTT toward a comprehensive, clinically applicable treatment for breast cancer.

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.

Versatile biomimetic nanomedicine for treating cancer and inflammation disease

Nanosized drug delivery systems (NDDSs) have emerged as a powerful tool to optimize drug delivery in complex diseases, including cancer and inflammation. However, the therapeutic effect of NDDSs is still far from satisfactory due to their poor circulation time, low delivery efficiency, and innate toxicity. Fortunately, biomimetic approaches offer new opportunities to develop nanomedicine, which is derived from a variety of native biomolecules including cells, exosomes, bacteria, and so on. Since inheriting the superior biocompatibility and versatile functions of natural materials, biomimetic nanomedicine can mimic biological processes, prolong blood circulation, and lower immunogenicity, serving as a desired platform for precise drug delivery for treating cancer and inflammatory disease. In this review, we outline recent advances in biomimetic NDDSs, which consist of two concepts: biomimetic exterior camouflage and bioidentical molecule construction. We summarize engineering strategies that further functionalized current biomimetic NDDSs. A series of functional biomimetic NDDSs created by our group are introduced. We conclude with an outlook on remaining challenges and possible directions for biomimetic NDDSs. We hope that better technologies can be inspired and invented to advance drug delivery systems for cancer and inflammation therapy.

Multifunctional nanoparticle for cancer therapy

Cancer is a complex disease associated with a combination of abnormal physiological process and exhibiting dysfunctions in multiple systems. To provide effective treatment and diagnosis for cancer, current treatment strategies simultaneously focus on various tumor targets. Based on the rapid development of nanotechnology, nanocarriers have been shown to exhibit excellent potential for cancer therapy. Compared with nanoparticles with single functions, multifunctional nanoparticles are believed to be more aggressive and potent in the context of tumor targeting. However, the development of multifunctional nanoparticles is not simply an upgraded version of the original function, but involves a sophisticated system with a proper backbone, optimized modification sites, simple preparation method, and efficient function integration. Despite this, many well-designed multifunctional nanoparticles with promising therapeutic potential have emerged recently. Here, to give a detailed understanding and analyzation of the currently developed multifunctional nanoparticles, their platform structures with organic or inorganic backbones were systemically generalized. We emphasized on the functionalization and modification strategies, which provide additional functions to the nanoparticle. We also discussed the application combination strategies that were involved in the development of nanoformulations with functional crosstalk. This review thus provides an overview of the construction strategies and application advances of multifunctional nanoparticles.

Recent Advances in Contrast-Enhanced Photoacoustic Imaging: Overcoming the Physical and Practical Challenges

For decades now, photoacoustic imaging (PAI) has been investigated to realize its potential as a niche biomedical imaging modality. Despite its highly desirable optical contrast and ultrasonic spatiotemporal resolution, PAI is challenged by such physical limitations as a low signal-to-noise ratio (SNR), diminished image contrast due to strong optical attenuation, and a lower-bound on spatial resolution in deep tissue. In addition, contrast-enhanced PAI has faced practical limitations such as insufficient cell-specific targeting due to low delivery efficiency and difficulties in developing clinically translatable agents. Identifying these limitations is essential to the continuing expansion of the field, and substantial advances in developing contrast-enhancing agents, complemented by high-performance image acquisition systems, have synergistically dealt with the challenges of conventional PAI. This review covers the past four years of research on pushing the physical and practical challenges of PAI in terms of SNR/contrast, spatial resolution, targeted delivery, and clinical application. Promising strategies for dealing with each challenge are reviewed in detail, and future research directions for next generation contrast-enhanced PAI are discussed.

Targeting drugs to tumours using cell membrane-coated nanoparticles

Traditional cancer therapeutics, such as chemotherapies, are often limited by their non-specific nature, causing harm to non-malignant tissues. Over the past several decades, nanomedicine researchers have sought to address this challenge by developing nanoscale platforms capable of more precisely delivering drug payloads. Cell membrane-coated nanoparticles (CNPs) are an emerging class of nanocarriers that have demonstrated considerable promise for biomedical applications. Consisting of a synthetic nanoparticulate core camouflaged by a layer of naturally derived cell membranes, CNPs are adept at operating within complex biological environments; depending on the type of cell membrane utilized, the resulting biomimetic nanoformulation is conferred with several properties typically associated with the source cell, including improved biocompatibility, immune evasion and tumour targeting. In comparison with traditional functionalization approaches, cell membrane coating provides a streamlined method for creating multifunctional and multi-antigenic nanoparticles. In this Review, we discuss the history and development of CNPs as well as how these platforms have been used for cancer therapy. The application of CNPs for drug delivery, phototherapy and immunotherapy will be described in detail. Translational efforts are currently under way and further research to address key areas of need will ultimately be required to facilitate the successful clinical adoption of CNPs.

Synergic Thermo- and pH-Sensitive Hybrid Microgels Loaded with Fluorescent Dyes and Ultrasmall Gold Nanoparticles for Photoacoustic Imaging and Photothermal Therapy

Smart microgels (μGels) made of polymeric particles doped with inorganic nanoparticles have emerged recently as promising multifunctional materials for nanomedicine applications. However, the synthesis of these hybrid materials is still a challenging task with the necessity to control several features, such as particle sizes and doping levels, in order to tailor their final properties in relation to the targeted application. We report herein an innovative modular strategy to achieve the rational design of well-defined and densely filled hybrid particles. It is based on the assembly of the different building blocks, i.e., μGels, dyes, and small gold nanoparticles (<4 nm), and the tuning of nanoparticle loading within the polymer matrix through successive incubation steps. The characterization of the final hybrid networks using UV-vis absorption, fluorescence, transmission electron microscopy, dynamic light scattering, and small-angle X-ray scattering revealed that they uniquely combine the properties of hydrogel particles, including high loading capacity and stimuli-responsive behavior, the photoluminescent properties of dyes (rhodamine 6G, methylene blue and cyanine 7.5), and the features of gold nanoparticle assembly. Interestingly, in response to pH and temperature stimuli, the smart hybrid μGels can shrink, leading to the aggregation of the gold nanoparticles trapped inside the polymer matrix. This stimuli-responsive behavior results in plasmon band broadening and red shift toward the near-infrared region (NIR), opening promising prospects in biomedical science. Particularly, the potential of these smart hybrid nanoplatforms for photoactivated hyperthermia, photoacoustic imaging, cellular internalization, intracellular imaging, and photothermal therapy was assessed, demonstrating well controlled multimodal opportunities for theranostics.

One stone, many birds: Recent advances in functional nanogels for cancer nanotheranostics

Inspired by the development of nanomedicine and nanotechnology, more and more possibilities in cancer theranostic have been provided in the last few years. Emerging therapeutic modalities like starvation therapy, chemodynamic therapy, and tumor oxygenation have been integrated with diagnosis, giving a plethora of theranostic nanoagents. Among all of them, nanogels (NGs) show superiority benefiting from their unique attributes: high stability, high water-absorption, large specific surface area, mechanical strength, controlled responsiveness, and high encapsulation capacity. There have been a vast number of investigations supporting various NGs combining drug delivery and multiple bioimaging techniques, encompassing photothermal imaging, photoacoustic imaging, fluorescent imaging, ultrasound imaging, magnetic resonance imaging, and computed tomography. This review summarizes recent advances in functional NGs for theranostic nanomedicine and discusses the challenges and future perspectives of this fast-growing field. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

Looking deep inside tissue with photoacoustic molecular probes: a review

Significance

Deep tissue noninvasive high-resolution imaging with light is challenging due to the high degree of light absorption and scattering in biological tissue. Photoacoustic imaging (PAI) can overcome some of the challenges of pure optical or ultrasound imaging to provide high-resolution deep tissue imaging. However, label-free PAI signals from light absorbing chromophores within the tissue are nonspecific. The use of exogeneous contrast agents (probes) not only enhances the imaging contrast (and imaging depth) but also increases the specificity of PAI by binding only to targeted molecules and often providing signals distinct from the background.

Aim

We aim to review the current development and future progression of photoacoustic molecular probes/contrast agents.

Approach

First, PAI and the need for using contrast agents are briefly introduced. Then, the recent development of contrast agents in terms of materials used to construct them is discussed. Then, various probes are discussed based on targeting mechanisms, in vivo molecular imaging applications, multimodal uses, and use in theranostic applications.

Results

Material combinations are being used to develop highly specific contrast agents. In addition to passive accumulation, probes utilizing activation mechanisms show promise for greater controllability. Several probes also enable concurrent multimodal use with fluorescence, ultrasound, Raman, magnetic resonance imaging, and computed tomography. Finally, targeted probes are also shown to aid localized and molecularly specific photo-induced therapy.

Conclusions

The development of contrast agents provides a promising prospect for increased contrast, higher imaging depth, and molecularly specific information. Of note are agents that allow for controlled activation, explore other optical windows, and enable multimodal use to overcome some of the shortcomings of label-free PAI.

Fabrication of methylene blue-loaded ovalbumin/polypyrrole nanoparticles for enhanced phototherapy-triggered antitumour immune activation

BACKGROUND

Phototherapy-triggered immunogenic cell death (ICD) rarely elicits a robust antitumour immune response, partially due to low antigen exposure and inefficient antigen presentation. To address these issues, we developed novel methylene blue-loaded ovalbumin/polypyrrole nanoparticles (MB@OVA/PPY NPs) via oxidative polymerization and π-π stacking interactions.

RESULTS

The as-prepared MB@OVA/PPY NPs with outstanding photothermal conversion efficiency (38%) and photodynamic properties were readily internalized into the cytoplasm and accumulated in the lysosomes and mitochondria. Upon 808 nm and 660 nm laser irradiation, the MB@OVA/PPY NPs not only ablated tumour cells by inducing local hyperthermia but also damaged residual tumour cells by generating a large amount of reactive oxygen species (ROS), finally triggering the release of many damage-associated molecular patterns (DAMPs). Moreover, the MB@OVA/PPY NPs synergized with DAMPs to promote the maturation and improve the antigen presentation ability of DCs in vitro and in vivo.

CONCLUSIONS

This work reported a PPY NPs-based nanoplatform to encapsulate the therepeutic proteins and absorb the functional molecules for combination therapy of tumours. The results demonstrated that the prepared MB@OVA/PPY NPs could be used as effective nanotherapeutic agents to eliminate solid tumours and trigger a powerful antitumour immune response.

Bioengineered nanogels for cancer immunotherapy

Recent years have witnessed increasingly rapid advances in nanocarrier-based biomedicine aimed at improving treatment paradigms for cancer. Nanogels serve as multipurpose and constructed vectors formed via intramolecular cross-linking to generate drug delivery systems, which is attributed predominantly to their satisfactory biocompatibility, bio-responsiveness, high stability, and low toxicity. Recently, immunotherapy has experienced unprecedented growth and has become the preferred strategy for cancer treatment, and mainly involves the mobilisation of the immune system and an enhanced anti-tumour immunity of the tumour microenvironment. Despite the inspiring success, immunotherapeutic strategies are limited due to the low response rates and immune-related adverse events. Like other nanomedicines, nanogels are comparably limited by lower focal enrichment rates upon introduction into the organism via injection. Because nanogels are three-dimensional cross-linked aqueous materials that exhibit similar properties to natural tissues and are structurally stable, they can comfortably cope with shear forces and serum proteins in the bloodstream, and the longer circulation life increases the chance of nanogel accumulation in the tumour, conferring deep tumour penetration. The large specific surface area can reduce or eliminate off-target effects by introducing stimuli-responsive functional groups, allowing multiple physical and chemical modifications for specific purposes to improve targeting to specific immune cell subpopulations or immune organs, increasing the bioavailability of the drug, and conferring a low immune-related adverse events on nanogel therapies. The slow release upon reaching the tumour site facilitates long-term awakening of the host's immune system, ultimately achieving enhanced therapeutic effects. As an effective candidate for cancer immunotherapy, nanogel-based immunotherapy has been widely used. In this review, we mainly summarize the recent advances of nanogel-based immunotherapy to deliver immunomodulatory small molecule drugs, antibodies, genes and cytokines, to target antigen presenting cells, form cancer vaccines, and enable chimeric antigen receptor (CAR)-T cell therapy. Future challenges as well as expected and feasible prospects for clinical treatment are also highlighted.

Nanostructured particles assembled from natural building blocks for advanced therapies

Advanced treatments based on immune system manipulation, gene transcription and regulation, specific organ and cell targeting, and/or photon energy conversion have emerged as promising therapeutic strategies against a range of challenging diseases. Naturally derived macromolecules (e.g., proteins, lipids, polysaccharides, and polyphenols) have increasingly found use as fundamental building blocks for nanostructured particles as their advantageous properties, including biocompatibility, biodegradability, inherent bioactivity, and diverse chemical properties make them suitable for advanced therapeutic applications. This review provides a timely and comprehensive summary of the use of a broad range of natural building blocks in the rapidly developing field of advanced therapeutics with insights specific to nanostructured particles. We focus on an up-to-date overview of the assembly of nanostructured particles using natural building blocks and summarize their key scientific and preclinical milestones for advanced therapies, including adoptive cell therapy, immunotherapy, gene therapy, active targeted drug delivery, photoacoustic therapy and imaging, photothermal therapy, and combinational therapy. A cross-comparison of the advantages and disadvantages of different natural building blocks are highlighted to elucidate the key design principles for such bio-derived nanoparticles toward improving their performance and adoption. Current challenges and future research directions are also discussed, which will accelerate our understanding of designing, engineering, and applying nanostructured particles for advanced therapies.

Exosome-liposome hybrid nanoparticle codelivery of TP and miR497 conspicuously overcomes chemoresistant ovarian cancer

Background

Although cisplatin-based chemotherapy has been used as the first-line treatment for ovarian cancer (OC), tumor cells develop resistance to cisplatin during treatment, causing poor prognosis in OC patients. Studies have demonstrated that overactivation of the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway is involved in tumor chemoresistance and that overexpression of microRNA-497 (miR497) may overcome OC chemotherapy resistance by inhibiting the mTOR pathway. However, the low transcriptional efficiency and unstable chemical properties of miR497 limit its clinical application. Additionally, triptolide (TP) was confirmed to possess a superior killing effect on cisplatin-resistant cell lines, partially through inhibiting the mTOR pathway. Even so, the clinical applications of TP are restricted by serious systemic toxicity and weak water solubility.

Results

Herein, whether the combined application of miR497 and TP could further overcome OC chemoresistance by synergically suppressing the mTOR signaling pathway was investigated. Bioinspired hybrid nanoparticles formed by the fusion of CD47-expressing tumor exosomes and cRGD-modified liposomes (miR497/TP-HENPs) were prepared to codeliver miR497 and TP. In vitro results indicated that the nanoparticles were efficiently taken up by tumor cells, thus significantly enhancing tumor cell apoptosis. Similarly, the hybrid nanoparticles were effectively enriched in the tumor areas and exerted significant anticancer activity without any negative effects in vivo. Mechanistically, they promoted dephosphorylation of the overactivated PI3K/AKT/mTOR signaling pathway, boosted reactive oxygen species (ROS) generation and upregulated the polarization of macrophages from M2 to M1 macrophages.

Conclusion

Overall, our findings may provide a translational strategy to overcome cisplatin-resistant OC and offer a potential solution for the treatment of other cisplatin-resistant tumors.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01264-5.

Nanocarriers surface engineered with cell membranes for cancer targeted chemotherapy

Background

Inspired by nature, the biomimetic approach has been incorporated into drug nanocarriers for cancer targeted chemotherapy. The nanocarriers are cloaked in cell membranes, which enables them to incorporate the functions of natural cells.

Key scientific concepts of review

Nanocarriers surface engineered with cell membranes have emerged as a fascinating source of materials for cancer targeted chemotherapy. A distinctive characteristic of cell membrane-coated nanocarriers (CMCNs) is that they include carbohydrates, proteins, and lipids, in addition to being biocompatible. CMCNs are capable of interacting with the complicated biological milieu of the tumor because they contain the signaling networks and intrinsic functions of their parent cells. Numerous cell membranes have been investigated for the purpose of masking nanocarriers with membranes, and various tumor-targeting methods have been devised to improve cancer targeted chemotherapy. Moreover, the diverse structure of the membrane from different cell sources broadens the spectrum of CMCNs and offers an entirely new class of drug-delivery systems.

Aim of review

This review will describe the manufacturing processes for CMCNs and the therapeutic uses for different kinds of cell membrane-coated nanocarrier-based drug delivery systems, as well as addressing obstacles and future prospects.

Graphical Abstract

Applying Synthetic Biology with Rational Design to Nature’s Greatest Challenges: Bioengineering Immunotherapeutics for the Treatment of Glioblastoma

Improvements in bioengineering methodology and tools have allowed for significant progress in the development of therapeutics and diagnostics in medicine, as well as progress in many other diverse industries, such as materials manufacturing, food and agriculture, and consumer goods. Glioblastomas present significant challenges to adequate treatment, in part due to their immune-evasive and manipulative nature. Rational-design bioengineering using novel scaffolds, biomaterials, and inspiration across disciplines can push the boundaries in treatment development to create effective therapeutics for glioblastomas. In this review, we will discuss bioengineering strategies currently applied across diseases and disciplines to inspire creative development for GBM immunotherapies.

Nano drug delivery systems improve metastatic breast cancer therapy

Despite continual progress in the technologies and regimens for cancer therapy, the treatment outcome of fatal metastatic breast cancer is far from satisfactory. Encouragingly, nanotechnology has emerged as a valuable tool to optimize drug delivery process in cancer therapy via preventing the cargos from degradation, improving the tumor-targeting efficiency, enhancing therapeutic agents' retention in specific sites, and controlling drug release. In the last decade, several mechanisms of suppressing tumor metastasis by functional nano drug delivery systems (NDDSs) have been revealed and a guidance for the rational design of anti-metastasis NDDSs is summarized, which consist of three aspects: optimization of physiochemical properties, tumor microenvironment remodeling, and biomimetic strategies. A series of medicinal functional biomaterials and anti-metastatic breast cancer NDDSs constructed by our team are introduced in this review. It is hoped that better anti-metastasis strategies can be inspired and applied in clinic.

Cell Membrane-Coated Mimics: A Methodological Approach for Fabrication, Characterization for Therapeutic Applications, and Challenges for Clinical Translation

Cell membrane-coated (CMC) mimics are micro/nanosystems that combine an isolated cell membrane and a template of choice to mimic the functions of a cell. The design exploits its physicochemical and biological properties for therapeutic applications. The mimics demonstrate excellent biological compatibility, enhanced biointerfacing capabilities, physical, chemical, and biological tunability, ability to retain cellular properties, immune escape, prolonged circulation time, and protect the encapsulated drug from degradation and active targeting. These properties and the ease of adapting them for personalized clinical medicine have generated a significant research interest over the past decade. This review presents a detailed overview of the recent advances in the development of cell membrane-coated (CMC) mimics. The primary focus is to collate and discuss components, fabrication methodologies, and the significance of physiochemical and biological characterization techniques for validating a CMC mimic. We present a critical analysis of the two main components of CMC mimics: the template and the cell membrane and mapped their use in therapeutic scenarios. In addition, we have emphasized on the challenges associated with CMC mimics in their clinical translation. Overall, this review is an up to date toolbox that researchers can benefit from while designing and characterizing CMC mimics.

Hybrid membrane-coated nanosuspensions for multi-modal anti-glioma therapy via drug and antigen delivery

BACKGROUND

Glioma is one of the deadliest human cancers. Although many therapeutic strategies for glioma have been explored, these strategies are seldom used in the clinic. The challenges facing the treatment of glioma not only involve the development of chemotherapeutic drugs and immunotherapeutic agents, but also the lack of a powerful platform that could deliver these two moieties to the targeted sites. Herein, we developed chemoimmunotherapy delivery vehicles based on C6 cell membranes and DC membranes to create hybrid membrane-coated DTX nanosuspensions (DNS-[C6&DC]m).

RESULTS

Results demonstrated successful hybrid membrane fusion and nanosuspension functionalization, and DNS-[C6&DC]m could be used for different modes of anti-glioma therapy. For drug delivery, membrane coating could be applied to target the source cancer cells via a homotypic-targeting mechanism of the C6 cell membrane. For cancer immunotherapy, biomimetic nanosuspension enabled an immune response based on the professional antigen-presenting characteristic of the dendritic cell membrane (DCm), which carry the full array of cancer cell membrane antigens and facilitate the uptake of membrane-bound tumor antigens for efficient presentation and downstream immune n.

CONCLUSION

DNS-[C6&DC]m is a multifunctional biomimetic nano-drug delivery system with the potential to treat gliomas through tumor-targeted drug delivery combined with immunotherapy, thereby presenting a promising approach that may be utilized for multiple modes of cancer therapy.

In Vitro Anticancer Activity of Nanoformulated Mono- and Di-nuclear Pt Compounds

Nanoformulations of mononuclear Pt complexes cis-PtCl₂ (PPh₃ )₂ (1), [Pt(PPh₃ )₂ (L-Cys)] ⋅ H₂ O (3, L-Cys=L-cysteinate), trans-PtCl₂ (PPh₂ PhNMe₂ )₂ (4; PPh₂ PhNMe₂ =4-(dimethylamine)triphenylphosphine), trans-PtI₂ (PPh₂ PhNMe₂ )₂ (5) and dinuclear Pt cluster Pt₂ (μ-S)₂ (PPh₃ )₄ (2) have comparable cytotoxicity to cisplatin against murine melanoma cell line B16F10. Masking of these discrete molecular entities within the hydrophobic core of Pluronic® F-127 significantly boosted their solubility and stability, ensuring efficient cellular uptake, giving in vitro IC₅₀ values in the range of 0.87-11.23 μM. These results highlight the potential therapeutic value of Pt complexes featuring stable Pt-P bonds in nanocomposite formulations with biocompatible amphiphilic polymers.

Hybrid Membrane-Coated Biomimetic Nanoparticles (HM@BNPs): A Multifunctional Nanomaterial for Biomedical Applications

The application of nanoparticles in the diagnosis and treatment of diseases has undergone different developmental stages, but phagocytosis and nonspecific distribution have been the main factors restricting the transformation of nanobased drugs into clinical practice. In the past decade, the design of membrane-coated nanoparticles has gained increasing attention. It is hoped that the combination of the cell membrane's natural biological properties and the functional integration of synthetic nanoparticle systems can compensate for the shortage of traditional nanoparticles. The membrane coating gives the nanoparticles unique biological functions such as immune evasion and targeting capability. However, when the encapsulation of monotypic membranes does not meet the diverse demands of biomedicine, the combination of different cell membranes may offer more possibilities. In this review, the composition, preparation, and advantages of biomimetic nanoparticles coated with hybrid cell membranes are summarized, and the applications of hybrid membrane-coated biomimetic nanoparticles (HM@BNPs) in drug delivery, phototherapy, liquid biopsy, tumor vaccines, immune therapy, and detoxification are reviewed. Finally, the current challenges and opportunities with regard to HM@BNPs are discussed.

Nanomaterials to Fight Cancer: An Overview on Their Multifunctional Exploitability

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

Chemically Engineered Immune Cell-Derived Microrobots and Biomimetic Nanoparticles: Emerging Biodiagnostic and Therapeutic Tools

Over the past decades, considerable attention has been dedicated to the exploitation of diverse immune cells as therapeutic and/or diagnostic cell-based microrobots for hard-to-treat disorders. To date, a plethora of therapeutics based on alive immune cells, surface-engineered immune cells, immunocytes' cell membranes, leukocyte-derived extracellular vesicles or exosomes, and artificial immune cells have been investigated and a few have been introduced into the market. These systems take advantage of the unique characteristics and functions of immune cells, including their presence in circulating blood and various tissues, complex crosstalk properties, high affinity to different self and foreign markers, unique potential of their on-demand navigation and activity, production of a variety of chemokines/cytokines, as well as being cytotoxic in particular conditions. Here, the latest progress in the development of engineered therapeutics and diagnostics inspired by immune cells to ameliorate cancer, inflammatory conditions, autoimmune diseases, neurodegenerative disorders, cardiovascular complications, and infectious diseases is reviewed, and finally, the perspective for their clinical application is delineated.

Nano-delivery systems focused on tumor microenvironment regulation and biomimetic strategies for treatment of breast cancer metastasis

Breast cancer metastasis and recurrence accounts for vast majority of breast cancer-induced mortality. Tumor microenvironment (TME) plays an important role at each step of metastasis, evasion of immunosurveillance, and therapeutic resistance. Consequently, TME-targeting alternatives to traditional therapies focused on breast cancer cells are gaining increasing attention. These new therapies involve the use of tumor cells, and key TME components or secreted bioactive molecules as therapeutic targets, alone or in combination. Recently, TME-related nanoparticles have been developed to deliver various agents, such as bioactive ingredients extracted from natural sources or chemotherapeutic agents, genes, proteins, small interfering RNAs, and vaccines; they have shown great therapeutic potential against breast cancer metastasis. Among various types of nanoparticles, biomimetic nanovesicles are a promising means of addressing the limitations of conventional nanocarriers. This review highlights various nanoparticles related to or mediated by TME according to the key TME components responsible for metastasis. Furthermore, TME-related biomimetic nanoparticles against breast cancer metastasis have garnered attention owing to their promising efficiency, especially in payload delivery and therapeutic action. Here, we summarize recent representative studies on nanoparticles related to cancer-associated fibroblasts, extracellular matrix, endothelial cells, angiogenesis, and immune cells, as well as advanced biomimetic nanoparticles. Future challenges and opportunities in the field are also discussed.

Bio-Inspired and Smart Nanoparticles for Triple Negative Breast Cancer Microenvironment

Triple negative breast cancer (TNBC) with poor prognosis and aggressive nature accounts for 10-20% of all invasive breast cancer (BC) cases and is detected in as much as 15% of individuals diagnosed with BC. Currently, due to the absence of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 (HER2) receptor, there is no hormone-based therapy for TNBC. In addition, there are still no FDA-approved targeted therapies for patients with TNBC. TNBC treatment is challenging owing to poor prognosis, tumor heterogeneity, chemotherapeutic side effects, the chance of metastasis, and multiple drug-resistance. Therefore, various bio-inspired tumor-homing nano systems responding to intra- and extra- cellular stimuli are an urgent need to treat TNBC patients who do not respond to current chemotherapy. In this review, intensive efforts have been made for exploring cell-membrane coated nanoparticles and immune cell-targeted nanoparticles (immunotherapy) to modulate the tumor microenvironment and deliver accurate amounts of therapeutic agents to TNBC without stimulating the immune system.

Optimal synthesis of polyelectrolyte nanogels by electrostatic assembly directed polymerization for dye loading and release

Polyelectrolyte (PE) nanogels which combine features of nanogels and polyelectrolytes have attracted significant attention as outstanding nano-carriers. However, and crucially, any large-scale application of PE nanogels can only materialize when an efficient production method is available. We recently developed such a robust approach, namely Electrostatic Assembly Directed Polymerization (EADP), in which ionic monomers are polymerized together with cross-linker in the presence of a polyion-neutral diblock copolymer as template. Although EADP achieves efficient and scalable preparation of diverse PE nanogels, the essential factors for the optimal and controlled synthesis of nanogels have remained elusive. In this article, we investigate systematically the effects of pH, salt concentration, and cross-linker fractions on the formation and properties of a PDMAEMA nanogel prepared with PAA-b-PEO as the template. We find that the electrostatic interaction between the building blocks is crucial to obtain assembly-controlled polymerization, and we establish preferred pH, salt concentration and cross-linker fractions. The obtained PDMAEMA nanogel exhibits dual-responses to pH and salt, which allow manipulation of the positive charges of the nanogels for selective loading and controlled release of anionic substances; we demonstrate this with an anionic dye. The study presented here fully addresses the process parameters of EADP regarding optimal and controlled preparation of PE nanogels, which should allow exploration of their potential vis-a-vis a variety of applications.

Adsorption of Methylene Blue Dye by Calix[6]Arene-Modified Lead Sulphide (Pbs): Optimisation Using Response Surface Methodology

Lead sulphide (PbS) modified with calix[6]arene was synthesised as an alternative and regenerative adsorbent for the adsorption of methylene blue (MB) dye. The prepared calix[6]arene-modified PbS was characterised via Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The response surface methodology (RSM) based on the central composite design (CCD) was employed to identify the most significant factors, such as the initial concentration, adsorbent dosage, pH, and temperature, and to optimise the effects of the factors on the adsorptive efficiency as its response. The optimised initial concentration, adsorbent dosage, pH, and temperature were 20.00 mg/L initial concentration, 44.00 mg calix[6]arene-modified PbS, pH 6, and a temperature of 31.00 °C. A good correlation between the values and well-fitted model was observed. The adsorption performance was evaluated based on the percentage removal of MB dye from the water system. The adsorption isotherm best fit the Langmuir isotherm model, and the adsorption rate was followed by a pseudo-second-order kinetic model, a single layer chemical adsorption with a maximum adsorption capacity (q_max) of 5.495 mg/g.

A porous material excited by near-infrared light for photo/chemodynamic and photothermal dual-mode combination therapy

Photodynamic therapy (PDT) and photothermal therapy (PTT) are well-developed light therapy methods for cancer; however, both have a few areas that need improvement. A sustained PDT effect depends on the sustained generation of reactive oxygen species (ROS); therefore, adjusting the type of photosensitizer or the reaction mechanism to prolong the duration of the oxidation-reduction reaction is a possible solution for the continuation of the PDT effect. Further, if PTT could be combined with other treatments, it would bring about a more satisfactory therapeutic effect. To increase the treatment effect of the above two therapeutic methods, a collaborative treatment model of photo/chemodynamic therapy (PCDT) and PTT is needed and is the focus of this study. On the one hand, PCDT is a therapy that integrates PDT with Fenton-like reactions, and Fenton-like reactions can help PDT to produce more ROS by making better use of H₂O₂ in the tumor microenvironment. On the other hand, the PTT effect can also promote PCDT effects to some extent because rising temperature can elevate the redox reaction rate. Therefore, a copper oxide semiconductor photosensitizer was selected in this research to realize the abovementioned therapeutic purposes and experimental concepts. A porous silica carrier can facilitate the uniform attachment of the copper oxide photosensitizer to the SiO₂ surface to form a relatively uniform nanostructure, and the nanoporous structure can increase the performance of the whole material to a certain extent. Based on these perspectives, SiO₂@CuO nanotube (NT), an agent of both Fenton-like photosensitization and photothermal reagent, is synthesized by the hydrothermal co-precipitation template approach to shrink the tumor through the combined effect of PCDT and PTT. In this system, copper ions can participate in the Fenton-like reactions and make better use of H₂O₂ to generate more ROS. Herein, 808 nm light was chosen for irradiation because of its suitable excitation ability, applicable penetration and low intrinsic damage. The experimental results show that SiO₂@CuO NT is a promising agent that combines PCDT and PTT for cancer treatment. This work provides guidance for the synthesis of Fenton-like photosensitizers for the PCDT effect.

Nanogels with Selective Intracellular Reactivity for Intracellular Tracking and Delivery

A multimodal approach for hydrogel-based nanoparticles was developed to selectively allow molecular conjugated species to either be released inside the cell or remain connected to the polymer network. Using the intrinsic difference in reactivity between esters and amides, nanogels with an amide-conjugated dye could be tracked intracellularly localizing next to the nucleus, while ester-conjugation allowed for liberation of the molecular species from the hydrogel network inside the cell, enabling delivery throughout the cytoplasm. The release was a result of particle exposure to the intracellular environment. The conjugation approach and polymer network building rely on the same chemistry and provide a diverse range of possibilities to be used in nanomedicine and theranostic approaches.

Engineering two-dimensional silicene composite nanosheets for dual-sensitized and photonic hyperthermia-augmented cancer radiotherapy

The rapid development of nanotechnology has triggered the emerging of tremendous theranostic nanoplatforms for combating cancers. Silicene, as an emerging two-dimensional (2D) material, has been recently explored as therapeutic agent due to their desirable biodegradation and strong photothermal-conversion performance. However, the rational design of silicene-based composites for further exerting multifunctional medical applications is still highly challenging. Herein, we report on the construction of silicene-based silicene@Pt composite nanosheets for computed tomography (CT)/photoacoustic (PA) imaging-guided dual-sensitized radiotherapy combined with photonic tumor hyperthermia, which has been achieved by a seed-growth approach to in situ grow Pt components onto silicene nanosheets' surface. Especially, by functionalization of Pt components, these nanosheets could act as both contrast agents for CT imaging and dual radio-sensitizing agents for radiotherapy, which could deposit Pt-involved radiation energy (sensitized therapeutic process I) and overcome hypoxia-associated radio-resistance by Pt-catalytic O₂ generation from overexpressed H₂O₂ within the tumor microenvironment (sensitized therapeutic process II). The strong photothermal-conversion performance of silicene nanosheets not only endowed silicene@Pt composite nanosheets with photoacoustic imaging property, but also realized the photonic tumor hyperthermia and achieved a combined therapeutic effect with radiotherapy. This work not only broadens the biomedical applications of silicene, but also develops functionalization strategies of silicene for versatile biomedical applications.

Bortezomib-Encapsulated CuS/Carbon Dot Nanocomposites for Enhanced Photothermal Therapy via Stabilization of Polyubiquitinated Substrates in the Proteasomal Degradation Pathway

Photothermal therapy (PTT) is an emerging therapeutic strategy in the treatment of cancer; however, a critical challenge remains in the rational design of synergistic nanoparticles as a potential photothermal transduction agent that can effectively enhance the therapeutic outcome of PTT for tumor ablation. Herein, we rationally designed, developed, and characterized hollow-structured CuS nanoparticles composited with carbon dots (CuSCDs), which demonstrated excellent photothermal conversion efficiency under a 808 nm laser irradiation with enhanced biocompatibility and reduced toxicity. Following coating with a macrophage membrane hybridized with T7 peptide on the surface of the proteasome inhibitor loaded CuSCD, CuSCDB@MMT7 exhibited targeted specificity to cancer cells with the characteristics of immunity escaping and enhanced transferrin receptor-mediated endocytosis. Predominantly, CuSCDB@MMT7-triggered PTT exhibited the accumulation of the polyubiquitinated tumor suppressor protein that is heat stabilized under NIR induced hyperthermia, facilitating augmented tumor cell apoptosis and the attenuated metastasis. This study provides a proof-of-concept for the proteasome inhibitor-loaded CuS/carbon dot nanocomposite-PTT strategy and highlights a promising therapeutic strategy for realizing enhanced therapeutic outcomes for effective clinical cancer therapy.

Recent Advances in Crosslinked Nanogel for Multimodal Imaging and Cancer Therapy

Nanomaterials have been widely applied in the field of cancer imaging and therapy. However, conventional nanoparticles including micelles and liposomes may suffer the issue of dissociation in the circulation. In contrast, crosslinked nanogels the structures of which are covalently crosslinked have better physiological stability than micelles and liposomes, making them more suitable for cancer theranostics. In this review, we summarize recent advances in crosslinked nanogels for cancer imaging and therapy. The applications of nanogels in drug and gene delivery as well as development of novel cancer therapeutic methods are first introduced, followed by the introduction of applications in optical and multimodal imaging, and imaging-guided cancer therapy. The conclusion and future direction in this field are discussed at the end of this review.

Natural Hydrogels Applied in Photodynamic Therapy

Natural hydrogels are three-dimensional (3D) water-retaining materials with a skeleton consisting of natural polymers, their derivatives or mixtures. Natural hydrogels can provide sustained or controlled drug release and possess some unique properties of natural polymers, such as biodegradability, biocompatibility and some additional functions, such as CD44 targeting of hyaluronic acid. Natural hydrogels can be used with photosensitizers (PSs) in photodynamic therapy (PDT) to increase the range of applications. In the current review, the pertinent design variables are discussed along with a description of the categories of natural hydrogels available for PDT.

Cell membrane biomimetic nanoparticles for inflammation and cancer targeting in drug delivery

Nanoparticle capture and elimination by the immune system are great obstacles for drug delivery. Camouflaging nanoparticles with cell membrane represents a promising strategy to communicate and negotiate with the immune system. As a novel class of nanotherapeutics, such biomimetic nanoparticles inherit specific biological functionalities of the source cells (e.g., erythrocytes, immune cells, cancer cells and platelets) in order to evade immune elimination, prolong circulation time, and even target a disease region by virtue of the homing tendency of the cell membrane protein. In this review, we begin with an overview of different cell membranes that can be utilized to create a biointerface on nanoparticles. Subsequently, we elaborate on the state-of-the-art of cell membrane biomimetic nanoparticles for drug delivery. In particular, a summary of data on circulation capacity and targeting efficiency by camouflaged nanoparticles is presented. In addition to cancer therapy, inflammation treatment, as an emerging application of biomimetic nanoparticles, is specifically included. The challenges and outlook of this technology are discussed.

Research Progress in Bioinspired Drug Delivery Systems

INTRODUCTION

To tackle challenges associated with traditional drug carriers, investigators have explored cells, cellular membrane, and macromolecular components including proteins and exosomes for the fabrication of delivery vehicles, owing to their excellent biocompatibility, lower toxicity, lower immunogenicity and similarities with the host. Biomacromolecule- and biomimetic nanoparticle (NP)-based drug/gene carriers are drawing immense attention, and biomimetic drug delivery systems (BDDSs) have been conceived and constructed.

AREAS COVERED

This review focuses on BDDS based on mammalian cells, including blood cells, cancer cells, adult stem cells, endogenous proteins, pathogens and extracellular vesicles (EVs).

EXPERT OPINION

Compared with traditional drug delivery systems (DDSs), BDDSs are based on biological nanocarriers, exhibiting superior biocompatibility, fewer side effects, natural targeting, and diverse modifications. In addition to directly employing natural biomaterials such as cells, proteins, pathogens and EVs as carriers, BDDSs offer these advantages by mimicking the structure of natural nanocarriers through bioengineering technologies. Furthermore, BDDSs demonstrate fewer limitations and irregularities than natural materials and can overcome several shortcomings associated with natural carriers. Although research remains ongoing to resolve these limitations, it is anticipated that BDDSs possess the potential to overcome challenges associated with traditional DDS, with a promising future in the treatment of human diseases.

SiO2@Cu7S4 nanotubes for photo/chemodynamic and photo-thermal dual-mode synergistic therapy under 808 nm laser irradiation

Photodynamic therapy (PDT) is a light-based modality for tumor treatment that involves the generation of reactive oxygen species (ROS) by the combination of light, a photosensitizer, and molecular oxygen. Nevertheless, the therapeutic effects of PDT are limited by hypoxic conditions that worsen with oxygen consumption during the PDT process. Photo/chemodynamic therapy (PCDT) based on the Fenton reaction is one strategy to improve ROS generation, provided a highly effective Fenton reagent is developed. In this research, SiO₂@Cu₇S₄ nanotubes (NTs) were synthesized as a PCDT agent. This double-valence metal-sulfide composite material can react with H₂O₂ at the tumor site. SiO₂@Cu₇S₄ NTs can produce more ROS than the traditional PDT agents, and besides, they can also be used as a photothermal therapy (PTT) agent. SiO₂@Cu₇S₄ NTs will trigger the PTT effect under 808 nm irradiation and generate a large amount of heat to eradicate cancer cells. This heat will also promote the PCDT effect by increasing the reaction rate. Thus, the SiO₂@Cu₇S₄ NT is a suitable material for PCDT and PTT synergistic oncotherapy. The 808 nm laser is selected as the appropriate excitation source, providing adequate penetration and minimal harm to normal cells. The experimental data presented herein demonstrate the promising photosensitive, Fenton-like, and photothermal performance of SiO₂@Cu₇S₄ NTs. Furthermore, the findings could promote the development of PCDT and PTT synergistic therapy. Thus, this research provides a feasible method to design a single, multifunctional material for cancer treatment.

Enhancing the chemotherapeutic efficacy of platinum prodrug nanoparticles and inhibiting cancer metastasis by targeting iron homeostasis

Iron plays important roles in tumor growth and metastasis, and iron depletion has become a new therapeutic strategy for iron overload cancers. Cisplatin is widely applied in the clinical therapy of various malignancies, but it has no inhibitory effect on cancer metastasis. In the present study, we found that the combination of cisplatin and iron chelator Dp44mT resulted in enhanced cell apoptosis as well as attenuated cell mobility and migration in vitro. Next, we developed a nano-carrier system to promote intracellular drug accumulation and reduce the side effects in cancer cells. Results showed that the as-synthesized nanoparticles (NPs) exhibited excellent antitumor efficiency when combined with Dp44mT. In breast tumor-bearing mice, the combination of the NPs and Dp44mT dramatically prevented orthotopic mammary tumor growth and inhibited metastasis via downregulation of VEGFα, MMP2 and Vimentin. In conclusion, as a versatile nano-platform for the combination of chemotherapy and iron chelators, the current design holds great potential for metastasis-inhibited cancer therapy.

Nanotherapeutics for Antimetastatic Treatment

Tumor metastases, that is, the development of secondary tumors in organs distant from the primary tumor, and their treatment remain a serious problem in cancer therapy. The unique challenges for tracking and treating tumor metastases lie in the small size, high heterogeneity, and wide dispersion to distant organs of metastases. Recently, nanomedicines, with the capacity to precisely deliver therapeutic agents to both primary and secondary tumors, have demonstrated many potential benefits for metastatic cancer theranostics. Given the remarkable progression in emerging nanotherapeutics for antimetastatic treatment, it is timely to summarize the latest advances in this field. This review highlights the rationale, advantages, and challenges for integrating biomedical nanotechnology with cancer biology to develop antimetastatic nanotherapeutics.

Role of Ultrasound and Photoacoustic Imaging in Photodynamic Therapy for Cancer

Photodynamic therapy (PDT) is a phototoxic treatment with high spatial and temporal control and has shown tremendous promise in the management of cancer due to its high efficacy and minimal side effects. PDT efficacy is dictated by a complex relationship between dosimetry parameters such as the concentration of the photosensitizer at the tumor site, its spatial localization (intracellular or extracellular), light dose and distribution, oxygen distribution and concentration, and the heterogeneity of the inter- and intratumoral microenvironment. Studying and characterizing these parameters, along with monitoring tumor heterogeneity pre- and post-PDT, provides essential data for predicting therapeutic response and the design of subsequent therapies. In this review, we elucidate the role of ultrasound (US) and photoacoustic imaging in improving PDT-mediated outcomes in cancer-from tracking photosensitizer uptake and vascular destruction, to measuring oxygenation dynamics and the overall evaluation of tumor responses. We also present recent advances in multifunctional theranostic nanomaterials that can improve either US or photoacoustic imaging contrast, as well as deliver photosensitizers specifically to tumors. Given the wide availability, low-cost, portability and nonionizing nature of US and photoacoustic imaging, together with their capabilities of providing multiparametric morphological and functional information, these technologies are thusly inimitable when deployed in conjunction with PDT.

Cell Membrane-Camouflaged Nanocarriers for Cancer Diagnostic and Therapeutic

Cell membrane (CM)-camouflaged nanocarriers (CMNPs) are the tools of a biomimetic strategy that has attracted significant attention. With a wide range of nanoparticle cores and CMs available, various creative CMNP designs have been studied for cancer diagnosis and therapy. The various functional CM molecules available allow CMNPs to demonstrate excellent properties such as prolonged circulation time, immune escape ability, reduced systemic toxicity, and homologous targeting ability when camouflaged with CMs derived from various types of natural cells including red and white blood cells, platelets, stem cells, and cancer cells. In this review, we summarize various CMNPs employed for cancer chemotherapy, immunotherapy, phototherapy, and in vivo imaging. We also predict future challenges and opportunities for fundamental and clinical studies.