Recent advances in nanomaterials for enhanced photothermal therapy of tumors

Redox/NIR dual-responsive glutathione extended polyurethane urea electrospun membranes for synergistic chemo-photothermal therapy

Despite advancements in cancer treatments, therapies frequently exhibit high cytotoxicity, and surgery remains the predominant method for treating most solid tumors, often with limited success in preventing post-surgical recurrence. Implantable biomaterials, designed to release drugs at a localised site in response to specific stimuli, represent a promising approach for enhancing tumour therapy. In this study, a redox-responsive glutathione extended polyurethane urea (PolyCEGS) was used to produce paclitaxel (PTX) and gold nanorods (AuNRs) loaded electrospun membranes for combined redox/near-infrared (NIR) light-responsive release chemotherapy and hyperthermic effect. Electrospinning conditions were optimized to fabricate AuNR-loaded scaffolds, at three different AuNRs concentrations. The obtained membranes were characterized by scanning electron microscopy (SEM) analyses and photothermal profiles were evaluated by a thermocamera, showing a temperature increase, up to 42.5 °C, when exposed to NIR light (810 nm) at 3 W/cm2. The AuNRs/PTX loaded scaffolds exhibited sustained PTX release, with 15 % released over 30 days and almost 1.8 times more in a simulated reductive environment. Moreover, their excellent photothermal effects and NIR light-triggered release led to significant synergic cytotoxicity in human colon cancer (HCT-116) and human breast cancer (MCF-7) cell lines. This system potentially enables controllable locoregional PTX release at the tumour site post-surgery, preventing recurrence and enhancing cytotoxicity through combined drug and PTT effects, highlighting its potential for future anticancer treatments.

Nanoscale Metal-Organic Frameworks and Nanoscale Coordination Polymers: From Synthesis to Cancer Therapy and Biomedical Imaging

Recently, there has been significant interest in nanoscale metal-organic frameworks (NMOFs) characterized by ordered crystal structures and nanoscale coordination polymers (NCPs) featuring amorphous structures. These structures arise from the coordination interactions between inorganic metal ions or clusters and organic ligands. Their advantages, such as the ability to tailor composition and structure, efficiently encapsulate diverse therapeutic or imaging agents within porous frameworks, inherent biodegradability, and surface functionalization capability, position them as promising carriers in the biomedical fields. This review provides an overview of the synthesis and surface modification strategies employed for NMOFs and NCPs, along with their applications in cancer treatment and biological imaging. Finally, future directions and challenges associated with the utilization of NMOFs and NCPs in cancer treatment and diagnosis are also discussed.

Nanomaterial-mediated photothermal therapy modulates tumor-associated macrophages: applications in cancer therapy

Complex pathogenesis and diverse clinical features pose many challenges in selecting appropriate cancer treatment strategies. Recent studies have shown that tumor-associated macrophages (TAMs) play dual roles in both promoting and inhibiting tumor growth. TAMs not only contribute to tumor survival and metastasis but also impact the response to therapy. Nanomaterial-based photothermal therapy (PTT) strategies have been widely used as ablative therapies for various cancers. Many studies have demonstrated that nanomaterial-mediated PTT effectively shifts TAMs towards an anticancer phenotype, thus inducing tumor apoptosis. Therefore, a comprehensive understanding of the tumor immune microenvironment will undoubtedly accelerate advancements in tumor therapy. This paper summarizes the application of nanomaterial-mediated PTT for cancer treatment by modulating TAMs. It highlights the types of nanomaterials and near-infrared laser modes used in the treatment process, analyzes the physicochemical factors that influence the distribution of different isoforms in TAMs, and finally explores the specific therapeutic parameters and mechanisms of nanomaterial-mediated PTT to guide future research in related fields.

Metal-Phenolic Networks: A Promising Frontier in Cancer Theranostics

The burgeoning field of cancer theranostics has been significantly advanced by the development of Metal-Phenolic Networks (MPNs), a new class of supramolecular architectures that integrate the advantages of metals and polyphenols. This review focuses on MPNs and their promising applications in cancer theranostics. Through a systematic literature search spanning from 2010 to 2023 in databases including PubMed, Scopus, and Web of Science. The period of search was justified by the rapid evolution of nanomaterials in cancer therapy, with MPNs emerging as a significant player in biomedical applications within the specified timeframe. This review discusses the classification and structure of polyphenolic compounds, as well as their mechanisms of action in cancer treatment. The applications of MPNs in chemotherapy drug delivery, photothermal therapy, chemodynamic therapy, biomedical imaging, and synergistic therapy are especially detailed. The authors emphasize the significance of MPNs in cancer nanomedicine and look forward to their future development directions.

Recent advances in biomaterials based near-infrared mild photothermal therapy for biomedical application: A review

Mild photothermal therapy (MPTT) generates heat therapeutic effect at the temperature below 45 °C under near-infrared (NIR) irradiation, which has the advantages of controllable treatment efficacy, lower hyperthermia temperatures, reduced dosage, and minimized damage to surrounding tissues. Despite significant progress has been achieved in MPTT, it remains primarily in the stage of basic and clinical research and has not yet seen widespread clinical adoption. Herein, a comprehensive overview of the recent NIR MPTT development was provided, aiming to emphasize the mechanism and obstacles, summarize the used photothermal agents, and introduce various biomedical applications such as anti-tumor, wound healing, and vascular disease treatment. The challenges of MPTT were proposed with potential solutions, and the future development direction in MPTT was outlooked to enhance the prospects for clinical translation.

ROS-responsive self-assembly nanoplatform overcomes hypoxia for enhanced photodynamic therapy

Photodynamic therapy (PDT) has emerged as a promising treatment for malignant tumours in recent decades due to its impressive spatiotemporal selectivity, minimal invasiveness, and few adverse effects. Despite these advancements, there remain significant challenges in effectively delivering photosensitizers to tumours and overcoming tumour hypoxia to maximize the therapeutic benefits of PDT. Ongoing research efforts are focused on developing innovative strategies to overcome the above-mentioned challenges, such as nanoplatforms and combination therapy approaches. Hence, reactive oxygen species (ROS)-responsive polymeric micelles are promising candidates to enhance the distribution and retention of photosensitizers within tumours. Additionally, efforts to alleviate tumour hypoxia may further improve the anti-tumour effects of PDT. In this study, we designed ROS-responsive polymeric micelles (TC@PTP) co-loaded with a Tapp-COF, a porphyrin derivative, and capsaicin for PDT of melanoma. These ROS-responsive nanocarriers, constructed from thioketal (TK)-linked amphiphilic di-block copolymers (PEG5K-TK-PLGA5K), could accumulate in the tumor microenvironment and release drugs under the action of ROS. Capsaicin, acting as a biogenic respiratory inhibitor, suppressed mitochondrial respiration and the hypoxia-inducible factor 1 (HIF-1) signaling pathway, thereby increasing oxygen levels at the tumour site. These PDT-triggered ROS-responsive nanoparticles effectively alleviated the tumour hypoxic microenvironment and enhanced anti-tumour efficacy. With superior biocompatibility and tumour-targeting abilities, the platform holds great promise for advancing anti-tumour combination therapy.

Targeting tumor microenvironments with gold nanoparticles for enhanced photothermal therapy

Gold nano-drug delivery system-mediated photothermal therapy (PTT) has been widely studied in the field of anti-tumor. In order to achieve accurate drug release and improve photothermal efficiency, nano-drug delivery strategies targeting tumor microenvironment (TME) have become a hot research topic in recent years. This paper introduces four characteristics of the TME: hypoxia, low pH, high level of reactive oxygen species (ROS), and overexpression of enzymes. These differences between tumor and normal tissue become effective targets for tumor therapy. This paper summarizes the gold nano-drug delivery system that can target these four characteristics, so as to realize a large amount of drug aggregation at the tumor site and achieve efficient photothermal therapy. Moreover, the multi-response nano-drug delivery system can further control drug delivery and improve therapeutic effects. Finally, this paper also summarizes the gold nanoparticles for tumor therapy that have entered clinical trials so far. The purpose of this review is to discuss the research progress of enhanced photothermal therapy with gold nano-drug delivery systems targeting the TME, with a view to providing a reference for the future development of novel anti-tumor nanoplatforms and the clinical translation of gold nanoparticles.

Recent advances in near-infrared stimulated nanohybrid hydrogels for cancer photothermal therapy

Nanomedicine has emerged as a promising avenue for advancing cancer treatment, but the challenge of mitigating its in vivo side effects necessitates the development of innovative structures and materials. Recent investigation has unveiled nanogels as particularly compelling candidates, characterized by a porous, three-dimensional network architecture that exhibits exceptional drug loading capacity. Beyond this, nanogels boast a substantial specific surface area and can be tailored with specific chemical functionalities. Consequently, nanogels are frequently engineered as a multi-modal synergistic platform for combating cancer, wherein photothermal therapy stands out due to its capacity to penetrate deep tissues and achieve localized tumor eradication through the application of elevated temperatures. In this review, we delve into the synthesis of diverse varieties of photothermal nanogels capable of controlled drug release triggered by either chemical or physical stimuli. It also summarizes their potential for synergistic integration with photothermal therapy alongside other therapeutic modalities to realize effective tumor ablation. Moreover, we analyze the primary mechanisms underlying the contribution of photothermal nanogels to cancer treatment while underscoring their adeptness in regulating therapeutic temperatures for repairing bone defects resulting from tumor-associated trauma. Envisioned as an auspicious strategy in the realm of cancer therapy, photothermal nanogels hold promise for furnishing controlled drug delivery and precise thermal ablation capabilities.

Double safety guarantees: Food-grade photothermal complex with a pH-triggered NIR absorption from zero to one

Photothermal therapy has aroused great attention and showed promising potential in minimally invasive tumor ablation, but the clinical translation is still stifled by the concerns of unwanted injury to normal tissues. The safety concerns might be completely solved only when the two security obstacles of "material-toxicity" and "photo-toxicity" were overcome simultaneously. Herein, a completely non-toxic food-grade photothermal transduction agent (PTA) with double safety guarantees was invented, which shows an absolute transformation of the photothermal effect from "0" to "1" after being triggered by an acidic tumor microenvironment. Inspired by the classical starch-iodine test, a preprogrammed [starch-KI-KIO3] complex was prepared in large quantities through a modified wet-milling procedure. It's demonstrated that a macroscopic consecutive reaction could be triggered by low pH to produce the starch-iodine complex which can generate lethal temperature under the near-infrared light irradiation. Meanwhile, the PTA shows excellent biocompatibility with no "material-toxicity" owing to the raw materials drawn from our daily food. Animal experiments reveal that the tumor microenvironment can activate the switch of photothermal effect from "0" to "1" successfully, which is thus responsible for the discriminative photo-damage to the tumor region while no "photo-toxicity" to normal tissue. The good treatment efficacy confirms the feasibility of such photothermal transduction agents with double safety guarantees in clinical applications.

Aggregable gold nanoparticles for cancer photothermal therapy

Photothermal therapy (PTT) is an important non-invasive cancer treatment method. Enhancing the photothermal conversion efficiency (PCE) of photothermal agents (PTAs) and prolonging their tumor accumulation and retention are effective strategies to enhance the efficiency of cancer PTT. Recently, tremendous progress has been made in developing stimuli-responsive aggregable gold nanoparticles as effective PTAs for PTT. In this review, we discuss the chemical principles underlying gold nanoparticle aggregation and highlight the progress in gold nanoparticle aggregation triggered by different stimuli, especially tumor microenvironment-related factors, for cancer PTT. Covalent condensation reactions, click cycloaddition reactions, chelation reactions, and Au-S bonding, as well as non-covalent electrostatic interactions, hydrophobic interactions, hydrogen bonding, and van der Waals forces play key roles in the aggregation of gold nanoparticles. Enzymes, pH, reactive oxygen species, small molecules, salts, and light drive the occurrence of gold nanoparticle aggregation. Targeted aggregation of gold nanoparticles prolongs tumor accumulation and retention of PTAs and improves PCE, resulting in enhanced tumor PTT. Moreover, the major challenges of aggregable gold nanoparticles as PTAs are pointed out and the promising applications are also prospected at the end. With the deepening of research, we expect aggregable gold nanoparticles to become essential PTAs for tumor therapy.

New features of edge-selectively hydroxylated graphene nanosheets as NIR-II photothermal agent and sonothermal agent for tumor therapy

Second near-infrared (NIR-II) laser-mediated photothermal therapy and sonothermal therapy using low-intensity focused ultrasound exposure for tumors have attracted increasing attention owing to their ability to penetrate deep tissues and provide noninvasive ablation with high therapeutic efficacy. However, their applications were limited by the shortness of optimal NIR-II photothermal agents and sonothermal agents. In this study, we discovered that the edge-selectively hydroxylated graphene nanosheets (EHG NSs) with excellent water dispersibility and an "intact conjugated plane" were not only an outstanding NIR-II photothermal agent but also an effective sonothermal agent for tumor therapy. EHG NSs were incorporated into an injectable adhesive thermosensitive hydrogel with a characteristic sol-gel phase transition behavior. EHG NSs endowed the injectable hydrogel with an exceptional photothermal effect under the laser irradiation (1064 nm, 1.0 W cm-2) as well as an effective sonothermal effect under ultrasonic exposure (3.0 MHz, 2.1 W cm-2), effectively killing tumor cells in vitro and inhibiting tumor growth after intratumoral injection. Especially, the NIR-II photothermal therapy based on the hybrid hydrogel completely ablated the primary tumors and effectively activated systemic anti-tumor immune responses benefiting from the protein adsorption capacity of the injectable hydrogel, significantly inhibiting the growth of the distal tumors. Collectively, EHG nanosheets loaded in the injectable hydrogel will be a promising "all-rounder" for noninvasive deep penetrating thermotherapy and a potent platform that integrates various therapies.

Targeted Delivery of Quinoxaline-Based Semiconducting Polymers for Tumor Photothermal Therapy

Photothermal therapy (PTT) holds great potential in the field of cancer treatment due to its high specificity and low invasiveness. However, the low conversion efficiency, inadequate tumor accumulation, and limited cellular uptake continue to impede PTT effectiveness in treating tumors. The present study focuses on the utilization of quinoxaline and its nanoparticles to develop an organic semiconducting photothermal agent (PAQI-BDTT) for tumor photothermal therapy. To achieve this, PAQI-BDTT was encapsulated within liposomes modified with cyclic Arg-Gly-Asp (cRGD) peptide targeting tumors (named T-BDTT-Lipo). Notably, T-BDTT-Lipo demonstrated a positive photothermal conversion efficiency of 74% when exposed to an 808 nm laser, along with NIR-II fluorescence imaging capabilities. The efficacy of T-BDTT-Lipo in tumor tissue accumulation and precise targeting of malignant cells has been confirmed through both in vitro and in vivo experiments guided by fluorescence imaging. Under single dose and 808 nm light irradiation, T-BDTT-Lipo generated local intracellular hyperthermia at the tumor site. The elevated temperature additionally exerted a significant inhibitory effect on tumor growth and recurrence, thereby extending the survival duration of mice harboring tumors. The therapeutic nanosystem (T-BDTT-Lipo) proposed in this work demonstrates the enormous potential of semiconducting photothermal agents in photothermal therapy, laying the foundation for the next clinical application.

Stimuli-Responsive Nanocomposite Hydrogels for Oral Diseases

Oral diseases encompassing conditions such as oral cancer, periodontitis, and endodontic infections pose significant challenges due to the oral cavity's susceptibility to pathogenic bacteria and infectious agents. Saliva, a key component of the oral environment, can compromise drug efficacy during oral disease treatment by diluting drug formulations and reducing drug-site interactions. Thus, it is imperative to develop effective drug delivery methods. Stimuli-responsive nanocomposite hydrogels offer a promising solution by adapting to changes in environmental conditions during disease states, thereby enabling targeted drug delivery. These smart drug delivery systems have the potential to enhance drug efficacy, minimize adverse reactions, reduce administration frequency, and improve patient compliance, thus facilitating a faster recovery. This review explores various types of stimuli-responsive nanocomposite hydrogels tailored for smart drug delivery, with a specific focus on their applications in managing oral diseases.

Stimuli Responsive Molecular Exchange of Structure Directing Agents on Gold Nanobipyramids: Cancer Cell Detection and Synergistic Therapeutics

Surface-engineered gold nanoparticles have been considered as versatile systems for theranostics applications. Moreover, surface covering or stabilizing agents on gold nanoparticles especially gold nanobipyramids (AuNBPs) provides an extra space for cargo molecules entrapment. However, it is not well studied yet and also the preparation of AuNBPs still remains dependent largely on cetyltrimethylammonium bromide (CTAB), a cytotoxic surfactant. Therefore, the direct use of CTAB stabilized nanoparticles is not recommended for cancer theranostics applications. Herein, we address an approach of dodecyl ethyl dimethylammonium bromide (DMAB) as biocompatible structure directing agent for AuNBPs, which also accommodate anticancer drug doxorubicin (45%), an additional chemotherapeutics agent. Upon near-infrared light (NIR, 808 nm) exposure, engineered AuNBPs exhibit (i) better phototransduction (51 °C) due to NIR absorption ability (650-900 nm), (ii) photo triggered drug release (more than 80%), and (iii) synergistic chemophototherapy for breast cancer cells. Drug release response has been evaluated in tumor microenvironment conditions (84% in acidic pH and 80% at high GSH) due to protonation and high affinity of thiol binding with AuNBPs followed by DMAB replacement. Intracellular glutathione (GSH, 5-7.5 mM) replaces DMAB from AuNBPs, which cause easy aggregation of nanoparticles as corroborated by colorimetric shifts, suggesting their utilization as a molecular sensing probe of early stage cancer biomarkers. Our optimized recipe yield is monodisperse DMAB-AuNBPs with ∼90% purity even at large scales (500 mL volume per batch). DMAB-AuNBPs show better cell viability (more than 90%) across all concentrations (5-500 ug/mL) when directly compared to CTAB-AuNBPs (less than 10%). Our findings show the potential of DMAB-AuNBPs for early stage cancer detection and theranostics applications.

From synthesis to applications of biomolecule-protected luminescent gold nanoclusters

Gold nanoclusters (AuNCs) are a class of novel luminescent nanomaterials that exhibit unique properties of ultra-small size, featuring strong anti-photo-bleaching ability, substantial Stokes shift, good biocompatibility, and low toxicity. Various biomolecules have been developed as templates or ligands to protect AuNCs with enhanced stability and luminescent properties for biomedical applications. In this review, the synthesis of AuNCs based on biomolecules including amino acids, peptides, proteins and DNA are summarized. Owing to the advantages of biomolecule-protected AuNCs, they have been employed extensively for diverse applications. The biological applications, particularly in bioimaging, biosensing, disease therapy and biocatalysis have been described in detail herein. Finally, current challenges and future potential prospects of bio-templated AuNCs in biological research are briefly discussed.

Making the Brightest Ones Dim: Maximizing the Photothermal Conversion Efficiency of BODIPY-Based Photothermal Agents

The successful implementation of photothermal therapy (PTT) in cancer treatment hinges on the development of highly effective photothermal agents (PTAs). Boron dipyrromethene (BODIPY) dyes, being well known for their high brightness and quantum efficiencies, are the antithesis of PTAs. Nonetheless, a systematic exploration of the photophysics and photothermal characteristics of a series of π-extended BODIPY dyes with high absorptivity in the near-infrared (NIR) region has achieved superior photothermal conversion efficiencies (>90%), in both monomeric state and nanoparticles after encapsulation in a biocompatible polyethyleneglycol 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy-(polyethylene glycol)-2000]. Optimal PTA candidates combine strong NIR absorption provided by extended donor-acceptor conjugation and an optimization of the electronic and steric effects of meso-substituents to maximize photothermal conversion performance. The PTT-optimized meso-CF3-BODIPY, TCF3PEn exhibits exceptional efficacy in inducing cancer cell apoptosis and in vivo tumor ablation using low-power NIR laser irradiation (0.3 W cm-2, 808 nm) as well as excellent biological safety, underscoring its potential for advancing light-induced cancer therapies.

Emerging Trends in Nanotechnology for Endometriosis: Diagnosis to Therapy

Endometriosis, an incurable gynecological disease that causes abnormal growth of uterine-like tissue outside the uterine cavity, leads to pelvic pain and infertility in millions of individuals. Endometriosis can be treated with medicine and surgery, but recurrence and comorbidities impair quality of life. In recent years, nanoparticle (NP)-based therapy has drawn global attention, notably in medicine. Studies have shown that NPs could revolutionize conventional therapeutics and imaging. Researchers aim to enhance the prognosis of endometriosis patients with less invasive and more effective NP-based treatments. This study evaluates this potential paradigm shift in endometriosis management, exploring NP-based systems for improved treatments and diagnostics. Insights into nanotechnology applications, including gene therapy, photothermal therapy, immunotherapy, and magnetic hyperthermia, offering a theoretical reference for the clinical use of nanotechnology in endometriosis treatment, are discussed in this review.

Magnetotactic Bacteria AMB-1 with Active Deep Tumor Penetrability for NIR-II Photothermal Tumor Therapy

The complex tumor structure and microenvironment such as abnormal tumor vasculature, dense tumor matrix, and elevated interstitial fluid pressure greatly hinder the penetration and retention of therapeutic agents in solid tumors. The development of an advanced method for robust penetration and retention of therapeutic agents in tumors is of great significance for efficient tumor treatments. In this work, we demonstrated that magnetotactic bacteria AMB-1 with hypoxic metabolism characteristics can actively penetrate the tumor to selectively colonize deep hypoxic regions, which emerge as a promising intelligent drug carrier. Furthermore, AMB-1 presents intrinsic second near-infrared (NIR-II) photothermal performance that can efficiently convert a 1064 nm laser into heat for tumor thermal ablation. We believe that our investigations not only develop a novel bacteria-based photothermal agent but also provide useful insights for the development of advanced tumor microbial therapies.

Manganese Dioxide-Based Nanomaterials for Medical Applications

Manganese dioxide (MnO2) nanomaterials can react with trace hydrogen peroxide (H2O2) to produce paramagnetic manganese (Mn2+) and oxygen (O2), which can be used for magnetic resonance imaging and alleviate the hypoxic environment of tumors, respectively. MnO2 nanomaterials also can oxidize glutathione (GSH) to produce oxidized glutathione (GSSG) to break the balance of intracellular redox reactions. As a consequence of the sensitivity of the tumor microenvironment to MnO2-based nanomaterials, these materials can be used as multifunctional diagnostic and therapeutic platforms for tumor imaging and treatment. Importantly, when MnO2 nanomaterials are implanted along with other therapeutics, synergetic tumor therapy can be achieved. In addition to tumor treatment, MnO2-based nanomaterials display promising prospects for tissue repair, organ protection, and the treatment of other diseases. Herein, we provide a thorough review of recent progress in the use of MnO2-based nanomaterials for biomedical applications, which may be helpful for the design and clinical translation of next-generation MnO2 nanomaterials.

Layered Double Hydroxides: Recent Progress and Promising Perspectives Toward Biomedical Applications

Layered double hydroxides (LDHs) have been widely studied for biomedical applications due to their excellent properties, such as good biocompatibility, degradability, interlayer ion exchangeability, high loading capacity, pH-responsive release, and large specific surface area. Furthermore, the flexibility in the structural composition and ease of surface modification of LDHs makes it possible to develop specifically functionalized LDHs to meet the needs of different applications. In this review, the recent advances of LDHs for biomedical applications, which include LDH-based drug delivery systems, LDHs for cancer diagnosis and therapy, tissue engineering, coatings, functional membranes, and biosensors, are comprehensively discussed. From these various biomedical research fields, it can be seen that there is great potential and possibility for the use of LDHs in biomedical applications. However, at the same time, it must be recognized that the actual clinical translation of LDHs is still very limited. Therefore, the current limitations of related research on LDHs are discussed by combining limited examples of actual clinical translation with requirements for clinical translation of biomaterials. Finally, an outlook on future research related to LDHs is provided.

Aggregation-enhanced photothermal therapy of organic dyes

Photothermal therapy (PTT) represents a groundbreaking approach to targeted disease treatment by harnessing the conversion of light into heat. The efficacy of PTT heavily relies on the capabilities of photothermal agents (PTAs). Among PTAs, those based on organic dyes exhibit notable characteristics such as adjustable light absorption wavelengths, high extinction coefficients, and high compatibility in biological systems. However, a challenge associated with organic dye-based PTAs lies in their efficiency in converting light into heat while maintaining stability. Manipulating dye aggregation is a key aspect in modulating non-radiative decay pathways, aiming to augment heat generation. This review delves into various strategies aimed at improving photothermal performance through constructing aggregation. These strategies including protecting dyes from photodegradation, inhibiting non-photothermal pathways, maintaining space within molecular aggregates, and introducing intermolecular photophysical processes. Overall, this review highlights the precision-driven assembly of organic dyes as a promising frontier in enhancing PTT-related applications. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

Cell Membrane as A Promising Therapeutic Target: From Materials Design to Biomedical Applications

The cell membrane is a crucial component of cells, protecting their integrity and stability while facilitating signal transduction and information exchange. Therefore, disrupting its structure or impairing its functions can potentially cause irreversible cell damage. Presently, the tumor cell membrane is recognized as a promising therapeutic target for various treatment methods. Given the extensive research focused on cell membranes, it is both necessary and timely to discuss these developments, from materials design to specific biomedical applications. This review covers treatments based on functional materials targeting the cell membrane, ranging from well-known membrane-anchoring photodynamic therapy to recent lysosome-targeting chimaeras for protein degradation. The diverse therapeutic mechanisms are introduced in the following sections: membrane-anchoring phototherapy, self-assembly on the membrane, in situ biosynthesis on the membrane, and degradation of cell membrane proteins by chimeras. In each section, we outline the conceptual design or general structure derived from numerous studies, emphasizing representative examples to understand advancements and draw inspiration. Finally, we discuss some challenges and future directions in membrane-targeted therapy from our perspective. This review aims to engage multidisciplinary readers and encourage researchers in related fields to advance the fundamental theories and practical applications of membrane-targeting therapeutic agents.

The roles of templates consisting of amino acids in the synthesis and application of gold nanoclusters

Gold nanoclusters (AuNCs) with low toxicity, high photostability, and facile synthesis have attracted great attention. The ligand is of great significance in stabilizing AuNCs and regulating their properties. Ligands consisting of amino acids (proteins and peptides) are an ideal template for synthesizing applicative AuNCs due to their inherent bioactivity, biocompatibility, and accessibility. In this review, we summarize the correlation of the template consisting of amino acids with the properties of AuNCs by analyzing different peptide sequences. The selection of amino acids can regulate the fluorescence excitation/emission and intensity, size, cell uptake, and light absorption. By analyzing the role played by AuNCs stabilized by proteins and peptides in the application, universal rules and detailed performances of sensors, antibacterial agents, therapeutic reagents, and light absorbers are reviewed. This review can guide the template design and application of AuNCs when selecting proteins and peptides as ligands.

Benzobisthiadiazole-Based Small Molecular Near-Infrared-II Fluorophores: From Molecular Engineering to Nanophototheranostics

Organic fluorescent molecules with emission in the second near-infrared (NIR-II) biological window have aroused increasing investigation in cancer phototheranostics. Among these studies, Benzobisthiadiazole (BBT), with high electron affinity, is widely utilized as the electron acceptor in constructing donor-acceptor-donor (D-A-D) structured fluorophores with intensive near-infrared (NIR) absorption and NIR-II fluorescence. Until now, numerous BBT-based NIR-II dyes have been employed in tumor phototheranostics due to their exceptional structure tunability, biocompatibility, and photophysical properties. This review systematically overviews the research progress of BBT-based small molecular NIR-II dyes and focuses on molecule design and bioapplications. First, the molecular engineering strategies to fine-tune the photophysical properties in constructing the high-performance BBT-based NIR-II fluorophores are discussed in detail. Then, their biological applications in optical imaging and phototherapy are highlighted. Finally, the current challenges and future prospects of BBT-based NIR-II fluorescent dyes are also summarized. This review is believed to significantly promote the further progress of BBT-derived NIR-II fluorophores for cancer phototheranostics.

Polyoxometalate-Nanozyme-Integrated Nanomotors (POMotors) for Self-Propulsion-Promoted Synergistic Photothermal-Catalytic Tumor Therapy

Enzyme-powered nanomotors have demonstrated promising potential in biomedical applications, especially for catalytic tumor therapy, owing to their ability of self-propulsion and bio-catalysis. However, the fragility of natural enzymes limits their environmental adaptability and also therapeutic efficacy in catalysis-enabled tumor therapy. Herein, polyoxometalate-nanozyme-based light-driven nanomotors were designed and synthesized for targeted synergistic photothermal-catalytic tumor therapy. In this construct, the peroxidase-like activity of the P2 W18 Fe4 polyoxometalates-based nanomotors can provide self-propulsion and facilitate their production of reactive oxygen species thus killing tumor cells, even in the weakly acidic tumor microenvironment. Conjugated polydopamine endows the nanomotors with the capability of light-driven self-propulsion behavior. After 10 min of NIR (808 nm) irradiation, along with the help of epidermal growth factor receptor antibody, the targeted accumulation and penetration of nanomotors in the tumor enabled highly efficient synergistic photothermal-catalytic therapy. This approach overcomes the disadvantages of the intrinsically fragile nature of enzyme-powered nanomotors in physiological environments and, more importantly, provides a motility-behavior promoted synergistic anti-tumor strategy.

Construction of Mn doped Cu7S4 nanozymes for synergistic tumor therapy in NIR-I/II bio-windows

In photothermal therapy (PTT) and chemodynamic therapy (CDT) of cancer, poor performance of nanoagents severely impaired the therapeutic effect of cancer. To solve the problem, we proposed and constructed a novel Mn doped Cu7S4 phothermal nanoagent both in the first near-infrared (NIR-I) and the second near- infrared (NIR-II) windows in this work, which exhibited high photothermal conversion efficiency of 40.3% at 808 nm (NIR-I window) and 33.4% at 1064 nm (NIR-II window), as well as outstanding pH-sensitive catalytic performance (peroxidase-like catalytic activity and Fenton-like catalytic activities). The as-prepared Mn doped Cu7S4 could be used to load chemotherapy drug doxorubicin (DOX) after modified by folic acid. Both in vitro and in vivo studies indicated that it could be used as nanoagent for chemodynamic therapy (CDT)/photothermal therapy (PTT)/ chemotherapy of cervical carcinoma. This study thus provided an NIR-I/NIR-II/pH responsive nanoagent for potential synergistic therapy of deep-seated tumors.

On the Importance of Low-Frequency Signals in Functional and Molecular Photoacoustic Computed Tomography

In photoacoustic computed tomography (PACT) with short-pulsed laser excitation, wideband acoustic signals are generated in biological tissues with frequencies related to the effective shapes and sizes of the optically absorbing targets. Low-frequency photoacoustic signal components correspond to slowly varying spatial features and are often omitted during imaging due to the limited detection bandwidth of the ultrasound transducer, or during image reconstruction as undesired background that degrades image contrast. Here we demonstrate that low-frequency photoacoustic signals, in fact, contain functional and molecular information, and can be used to enhance structural visibility, improve quantitative accuracy, and reduce spare-sampling artifacts. We provide an in-depth theoretical analysis of low-frequency signals in PACT, and experimentally evaluate their impact on several representative PACT applications, such as mapping temperature in photothermal treatment, measuring blood oxygenation in a hypoxia challenge, and detecting photoswitchable molecular probes in deep organs. Our results strongly suggest that low-frequency signals are important for functional and molecular PACT.

CoFeSe2 @DMSA@FA Nanocatalyst for Amplification of Oxidative Stress to Achieve Multimodal Tumor Therapy

Nanomedicine has significantly advanced precise tumor therapy, providing essential technical blessing for active drug accumulation, targeted consignment, and mitigation of noxious side effects. To enhance anti-tumor efficacy, the integration of multiple therapeutic modalities has garnered significant attention. Here, we designed an innovative CoFeSe2 @DMSA@FA nanocatalyst with Se vacancies (abbreviated as CFSDF), which exhibits synergistic chemodynamic therapy (CDT) and photothermal therapy (PTT), leading to amplified tumor oxidative stress and enhanced photothermal effects. The multifunctional CFSDF nanocatalyst exhibits the remarkable ability to catalyze the Fenton reaction within the acidic tumor microenvironment, efficiently converting hydrogen peroxide (H2 O2 ) into highly harmful hydroxyl radicals (⋅OH). Moreover, the nanocatalyst effectively diminishes GSH levels and ameliorates intracellular oxidative stress. The incorporation of FA modification enables CFSDF to evade immune detection and selectively target tumor tissues. Numerous in vitro and in vivo investigations have consistently demonstrated that CFSDF optimizes its individual advantages and significantly enhances therapeutic efficiency through synergistic effects of multiple therapeutic modalities, offering a valuable and effective approach to cancer treatment.

A continuously efficient O2-supplying strategy for long-term modulation of hypoxic tumor microenvironment to enhance long-acting radionuclides internal therapy

Radionuclides internal radiotherapy (RIT) is a clinically powerful method for cancer treatment, but still poses unsatisfactory therapeutic outcomes due to the hypoxic characteristic of tumor microenvironment (TME). Catalase (CAT) or CAT-like nanomaterials can be used to enzymatically decompose TME endogenous H2O2 to boost TME oxygenation and thus alleviate the hypoxic level within tumors, but their effectiveness is still hindered by the short-lasting of hypoxia relief owing to their poor stability or degradability, thereby failing to match the long therapeutic duration of RIT. Herein, we proposed an innovative strategy of using facet-dependent CAT-like Pd-based two-dimensional (2D) nanoplatforms to continuously enhance RIT. Specifically, rationally designed 2D Pd@Au nanosheets (NSs) enable consistent enzymatic conversion of endogenous H2O2 into O2 to overcome hypoxia-induced RIT resistance. Furthermore, partially coated Au layer afford NIR-II responsiveness and moderate photothermal treatment that augmenting their enzymatic functionality. This approach with dual-effect paves the way for reshaping TME and consequently facilitating the brachytherapy ablation of cancer. Our work offers a significant advancement in the integration of catalytic nanomedicine and nuclear medicine, with the overarching goal of amplifying the clinical benefits of RIT-treated patients.

Functionalized Nanomaterials for Inhibiting ATP-Dependent Heat Shock Proteins in Cancer Photothermal/Photodynamic Therapy and Combination Therapy

Phototherapies induced by photoactive nanomaterials have inspired and accentuated the importance of nanomedicine in cancer therapy in recent years. During these light-activated cancer therapies, a nanoagent can produce heat and cytotoxic reactive oxygen species by absorption of light energy for photothermal therapy (PTT) and photodynamic therapy (PDT). However, PTT is limited by the self-protective nature of cells, with upregulated production of heat shock proteins (HSP) under mild hyperthermia, which also influences PDT. To reduce HSP production in cancer cells and to enhance PTT/PDT, small HSP inhibitors that can competitively bind at the ATP-binding site of an HSP could be employed. Alternatively, reducing intracellular glucose concentration can also decrease ATP production from the metabolic pathways and downregulate HSP production from glucose deprivation. Other than reversing the thermal resistance of cancer cells for mild-temperature PTT, an HSP inhibitor can also be integrated into functionalized nanomaterials to alleviate tumor hypoxia and enhance the efficacy of PDT. Furthermore, the co-delivery of a small-molecule drug for direct HSP inhibition and a chemotherapeutic drug can integrate enhanced PTT/PDT with chemotherapy (CT). On the other hand, delivering a glucose-deprivation agent like glucose oxidase (GOx) can indirectly inhibit HSP and boost the efficacy of PTT/PDT while combining these therapies with cancer starvation therapy (ST). In this review, we intend to discuss different nanomaterial-based approaches that can inhibit HSP production via ATP regulation and their uses in PTT/PDT and cancer combination therapy such as CT and ST.

Nano-phototherapy: Favorable prospects for cancer treatment

Nanotechnology-based phototherapies have drawn interest in the fight against cancer because of its noninvasiveness, high flexibility, and precision in terms of cancer targeting and drug delivery based on its surface properties and size. Phototherapy has made remarkable development in recent decades. Approaches to phototherapy, which utilize nanomaterials or nanotechnology have emerged to contribute to advances around nanotechnologies in medicine, particularly for cancers. A brief overviews of the development of photodynamic therapy as well as its mechanism in cancer treatment is provided. We emphasize the design of novel nanoparticles utilized in photodynamic therapy while summarizing the representative progress during the recent years. Finally, to forecast important future research in this area, we examine the viability and promise of photodynamic therapy systems based on nanoparticles in clinical anticancer treatment applications and briefly make mention of the elimination of all reactive metabolites pertaining to nano formulations inside living organisms providing insight into clinical mechanistic processes. Future developments and therapeutic prospects for photodynamic treatments are anticipated. Our viewpoints might encourage scientists to create more potent phototherapy-based cancer therapeutic modalities. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Lonidamine liposomes to enhance photodynamic and photothermal therapy of hepatocellular carcinoma by inhibiting glycolysis

Phototherapy, including photodynamic therapy (PDT) and photothermal therapy (PTT), has great promise in the treatment of cancer. However, there are many obstacles that can restrict the therapeutic efficacy of phototherapy. The hypoxic tumor microenvironment can restrict the production of reactive oxygen species (ROS) in PDT. As for PTT, the thermotolerance of cancer cells may lead to ineffective PTT. In this study, IR780 and glycolysis inhibitor lonidamine (LND)-encapsulated liposomes are prepared for photodynamic and photothermal therapy of hepatocellular carcinoma. IR780 can be used as a photosensitizer and photothermal agent for simultaneous PDT and PTT after being irradiated with 808 nm laser. LND can reduce the oxygen consumption of cancer cells by inhibiting glycolysis, which will relieve tumor hypoxia and produce more ROS for PDT. On the other hand, energy supply can be blocked by LND-induced glycolysis inhibition, which will inhibit the production of heat shock proteins (HSPs), reduce the thermotolerance of tumor cells, and finally enhance the therapeutic efficacy of PTT. The enhanced PTT is studied by measuring intracellular HSPs, ATP level, and mitochondrial membrane potential. The antitumor effect of IR780 and LND co-loaded liposomes is extensively investigated by in vitro and in vivo experiments. This research provides an innovative strategy to simultaneously enhance the therapeutic efficacy of PDT and PTT by inhibiting glycolysis, which is promising for future creative approaches to cancer phototherapy.

Functionalized MoS2-nanosheets with NIR-Triggered nitric oxide delivery and photothermal activities for synergistic antibacterial and regeneration-promoting therapy

Bacterial infection in skin and soft tissue has emerged as a critical concern. Overreliance on antibiotic therapy has led to numerous challenges, including the emergence of multidrug-resistant bacteria and adverse drug reactions. It is imperative to develop non-antibiotic treatment strategies that not only exhibit potent antibacterial properties but also promote rapid wound healing and demonstrate biocompatibility. Herein, a novel multimodal synergistic antibacterial system (SNO-CS@MoS2) was developed. This system employs easily surface-modified thin-layer MoS2 as photothermal agents and loaded with S-nitrosothiol-modified chitosan (SNO-CS) via electrostatic interactions, thus realizing the combination of NO gas therapy and photothermal therapy (PTT). Furthermore, this surface modification renders SNO-CS@MoS2 highly stable and capable of binding with bacteria. Through PTT's thermal energy, SNO-CS@MoS2 rapidly generates massive NO, collaborating with PTT to achieve antibacterial effects. This synergistic therapy can swiftly disrupt the bacterial membrane, causing protein leakage and ATP synthesis function damage, ultimately eliminating bacteria. Notably, after effectively eliminating all bacteria, the residual SNO-CS@MoS2 can create trace NO to promote fibroblast migration, proliferation, and vascular regeneration, thereby accelerating wound healing. This study concluded that SNO-CS@MoS2, a novel multifunctional nanomaterial with outstanding antibacterial characteristics and potential to promote wound healing, has promising applications in infected soft tissue wound treatment.

Nano-modulators with the function of disrupting mitochondrial Ca2+ homeostasis and photothermal conversion for synergistic breast cancer therapy

Breast cancer treatment has been a global puzzle, and apoptosis strategies based on mitochondrial Ca2+ overload have attracted extensive attention. However, various limitations of current Ca2+ nanogenerators make it difficult to maintain effective Ca2+ overload concentrations. Here, we constructed a multimodal Ca2+ nano-modulator that, for the first time, combined photothermal therapy (PTT) and mitochondrial Ca2+ overload strategies to inhibit tumor development. By crosslinking sodium alginate (SA) on the surface of calcium carbonate (CaCO3) nanoparticles encapsulating with Cur and ICG, we prepared a synergistic Ca2+ nano-regulator SA/Cur@CaCO3-ICG (SCCI). In vitro studies have shown that SCCI further enhanced photostability while preserving the optical properties of ICG. After uptake by tumor cells, SCCI can reduce mitochondrial membrane potential and down-regulate ATP production by producing large amounts of Ca2+ at low pH. Near-infrared light radiation (NIR) laser irradiation made the tumor cells heat up sharply, which not only accelerated the decomposition of CaCO3, but also produced large amounts of reactive oxygen species (ROS) followed by cell apoptosis. In vivo studies have revealed that the Ca2+ nano-regulators had excellent targeting, biocompatibility, and anti-tumor effects, which can significantly inhibit the proliferation of tumor cells and play a direct killing effect. These findings indicated that therapeutic strategies based on ionic interference and PTT had great therapeutic potential, providing new insights into antitumor therapy.

Nanomaterials-Enabled Physicochemical Antibacterial Therapeutics: Toward the Antibiotic-Free Disinfections

Bacterial infection continues to be an increasing global health problem with the most widely accepted treatment paradigms restricted to antibiotics. However, the overuse and misuse of antibiotics have triggered multidrug resistance of bacteria, frustrating therapeutic outcomes, and leading to higher mortality rates. Even worse, the tendency of bacteria to form biofilms on living and nonliving surfaces further increases the difficulty in confronting bacteria because the extracellular matrix can act as a robust barrier to prevent the penetration of antibiotics and resist environmental damage. As a result, the inability to eliminate bacteria and biofilms often leads to persistent infection, implant failure, and device damage. Therefore, it is of paramount importance to develop alternative antimicrobial agents while avoiding the generation of bacterial resistance to prevent the large-scale growth of bacterial resistance. In recent years, nano-antibacterial materials have played a vital role in the antibacterial field because of their excellent physical and chemical properties. This review focuses on new physicochemical antibacterial strategies and versatile antibacterial nanomaterials, especially the mechanism and types of 2D antibacterial nanomaterials. In addition, this advanced review provides guidance on the development direction of antibiotic-free disinfections in the antibacterial field in the future.

Reconstituting Low-Density Lipoprotein with NIR-Absorbing Organic Photothermal Agents for Targeted Killing of Cancer Cells

Photothermal therapy (PTT) systems typically do not possess intrinsic tumor-targeting capability, resulting in indiscriminate thermal damage to both cancer and normal cells. Herein, a low-density lipoprotein (LDL)-based nanosystem (denoted as MTTQ@LDL) is reported for targeted photothermal killing of cancer cells. Such a nanosystem is fabricated by reconstituting the lipophilic core of LDL with an organic photothermal agent MTTQ. The reconstitution process improves the supramolecular photothermal effects of MTTQ assemblies, which contributes to the significantly enhanced photothermal conversion efficiency (41.3% vs. 16.2%). MTTQ@LDL can actively target LDL receptor-overexpressed cancer cells via receptor-mediated endocytosis, enabling the selective killing of cancer cells over normal cells (98% vs. 7%) post-NIR irradiation. Reconstituted LDL can serve as a promising platform for targeted delivery of functional materials, holding great promise in tumor eradication in vivo.

Codelivery of CuS and DOX into Deep Tumors with Size and Charge-Switchable PAMAM Dendrimers for Chemo-photothermal Therapy

Accurate targeting of therapeutic agents to specific tumor tissues, especially via deep tumor penetration, has been an effective strategy in cancer treatments. Here, we described a flexible nanoplatform, pH-responsive zwitterionic acylsulfonamide betaine-functionalized fourth-generation PAMAM dendrimers (G4-AB), which presented multiple advantages for chemo-photothermal therapy, including template synthesis of ultrasmall copper sulfide (CuS) nanoparticles and further encapsulation of doxorubicin (DOX) (G4-AB-DOX/CuS), long-circulating performance by a relatively large size and zwitterionic surface in a physiological environment, combined size shrinkage, and charge conversions via pH-responsive behavior in an acidic tumor microenvironment (TME). Accordingly, high tumor penetration and positive cell uptake for CuS and DOX have been determined, which triggered an excellent combination treatment under near-infrared irradiation in comparison to the monochemotherapy system and irresponsive chemo-photothermal system. Our study represented great promise in constructing multifunctional carriers for the effective delivery of photothermal nanoparticles and drugs in chemo-photothermal therapy.

Photothermal antibacterial materials to promote wound healing

Wound healing is a crucial process that restores the integrity and function of the skin and other tissues after injury. However, external factors, such as infection and inflammation, can impair wound healing and cause severe tissue damage. Therefore, developing new drugs or methods to promote wound healing is of great significance. Photothermal therapy (PTT) is a promising technique that uses photothermal agents (PTAs) to convert near-infrared radiation into heat, which can eliminate bacteria and stimulate tissue regeneration. PTT has the advantages of high efficiency, controllability, and low drug resistance. Hence, nanomaterial-based PTT and its related strategies have been widely explored for wound healing applications. However, a comprehensive review of PTT-related strategies for wound healing is still lacking. In this review, we introduce the physiological mechanisms and influencing factors of wound healing, and summarize the types of PTAs commonly used for wound healing. Then, we discuss the strategies for designing nanocomposites for multimodal combination treatment of wounds. Moreover, we review methods to improve the therapeutic efficacy of PTT for wound healing, such as selecting the appropriate wound dressing form, controlling drug release, and changing the infrared irradiation window. Finally, we address the challenges of PTT in wound healing and suggest future directions.

Application of Nanoparticles in Cancer Treatment: A Concise Review

Timely diagnosis and appropriate antitumoral treatments remain of utmost importance, since cancer remains a leading cause of death worldwide. Within this context, nanotechnology offers specific benefits in terms of cancer therapy by reducing its adverse effects and guiding drugs to selectively target cancer cells. In this comprehensive review, we have summarized the most relevant novel outcomes in the range of 2010-2023, covering the design and application of nanosystems for cancer therapy. We have established the general requirements for nanoparticles to be used in drug delivery and strategies for their uptake in tumor microenvironment and vasculature, including the reticuloendothelial system uptake and surface functionalization with protein corona. After a brief review of the classes of nanovectors, we have covered different classes of nanoparticles used in cancer therapies. First, the advances in the encapsulation of drugs (such as paclitaxel and fisetin) into nanoliposomes and nanoemulsions are described, as well as their relevance in current clinical trials. Then, polymeric nanoparticles are presented, namely the ones comprising poly lactic-co-glycolic acid, polyethylene glycol (and PEG dilemma) and dendrimers. The relevance of quantum dots in bioimaging is also covered, namely the systems with zinc sulfide and indium phosphide. Afterwards, we have reviewed gold nanoparticles (spheres and anisotropic) and their application in plasmon-induced photothermal therapy. The clinical relevance of iron oxide nanoparticles, such as magnetite and maghemite, has been analyzed in different fields, namely for magnetic resonance imaging, immunotherapy, hyperthermia, and drug delivery. Lastly, we have covered the recent advances in the systems using carbon nanomaterials, namely graphene oxide, carbon nanotubes, fullerenes, and carbon dots. Finally, we have compared the strategies of passive and active targeting of nanoparticles and their relevance in cancer theranostics. This review aims to be a (nano)mark on the ongoing journey towards realizing the remarkable potential of different nanoparticles in the realm of cancer therapeutics.

Current Application of Nanoparticle Drug Delivery Systems to the Treatment of Anaplastic Thyroid Carcinomas

Anaplastic thyroid carcinomas (ATCs) are a rare subtype of thyroid cancers with a low incidence but extremely high invasiveness and fatality. The treatment of ATCs is very challenging, and currently, a comprehensive individualized therapeutic strategy involving surgery, radiotherapy (RT), chemotherapy, BRAF/MEK inhibitors (BRAFi/MEKi) and immunotherapy is preferred. For ATC patients in stage IVA/IVB, a surgery-based comprehensive strategy may provide survival benefits. Unfortunately, ATC patients in IVC stage barely get benefits from the current treatment. Recently, nanoparticle delivery of siRNAs, targeted drugs, cytotoxic drugs, photosensitizers and other agents is considered as a promising anti-cancer treatment. Nanoparticle drug delivery systems have been mainly explored in the treatment of differentiated thyroid cancer (DTC). With the rapid development of drug delivery techniques and nanomaterials, using hybrid nanoparticles as the drug carrier to deliver siRNAs, targeted drugs, immune drugs, chemotherapy drugs and phototherapy drugs to ATC patients have become a hot research field. This review aims to describe latest findings of nanoparticle drug delivery systems in the treatment of ATCs, thus providing references for the further analyses.

Amplifying cancer treatment: advances in tumor immunotherapy and nanoparticle-based hyperthermia

In the quest for cancer treatment modalities with greater effectiveness, the combination of tumor immunotherapy and nanoparticle-based hyperthermia has emerged as a promising frontier. The present article provides a comprehensive review of recent advances and cutting-edge research in this burgeoning field and examines how these two treatment strategies can be effectively integrated. Tumor immunotherapy, which harnesses the immune system to recognize and attack cancer cells, has shown considerable promise. Concurrently, nanoparticle-based hyperthermia, which utilizes nanotechnology to promote selective cell death by raising the temperature of tumor cells, has emerged as an innovative therapeutic approach. While both strategies have individually shown potential, combination of the two modalities may amplify anti-tumor responses, with improved outcomes and reduced side effects. Key studies illustrating the synergistic effects of these two approaches are highlighted, and current challenges and future prospects in the field are discussed. As we stand on the precipice of a new era in cancer treatment, this review underscores the importance of continued research and collaboration in bringing these innovative treatments from the bench to the bedside.

Recent advances in fluorescence imaging-guided photothermal therapy and photodynamic therapy for cancer: From near-infrared-I to near-infrared-II

Phototherapy (including photothermal therapy, PTT; and photodynamic therapy, PDT) has been widely used for cancer treatment, but conventional PTT/PDT show limited therapeutic effects due to the lack of disease recognition ability. The integration of fluorescence imaging with PTT/PDT can reveal tumor locations in a real-time manner, holding great potential in early diagnosis and precision treatment of cancers. However, the traditional fluorescence imaging in the visible and near-infrared-I regions (VIS/NIR-I, 400-900 nm) might be interfered by the scattering and autofluorescence from tissues, leading to a low imaging resolution and high false positive rate. The deeper near-infrared-II (NIR-II, 1000-1700 nm) fluorescence imaging can address these interferences. Combining NIR-II fluorescence imaging with PTT/PDT can significantly improve the accuracy of tumor theranostics and minimize damages to normal tissues. This review summarized recent advances in tumor PTT/PDT and NIR-II fluorophores, especially discussed achievements, challenges and prospects around NIR-II fluorescence imaging-guided PTT/PDT for cancers.

Polymer Vesicles with Integrated Photothermal Responsiveness

Functionalized polymer vesicles have been proven to be highly promising in biomedical applications due to their good biocompatibility, easy processability, and multifunctional responsive capacities. However, photothermal-responsive polymer vesicles triggered by near-infrared (NIR) light have not been widely reported until now. Herein, we propose a new strategy for designing NIR light-mediated photothermal polymer vesicles. A small molecule (PTA) with NIR-triggered photothermal features was synthesized by combining a D-D'-A-D'-D configuration framework with a molecular rotor function (TPE). The feasibility of the design strategy was demonstrated through density functional theory calculations. PTA moieties were introduced in the hydrophobic segment of a poly(ethylene glycol)-poly(trimethylene carbonate) block copolymer, of which the carbonate monomers were modified in the side chain with an active ester group. The amphiphilic block copolymers (PEG44-PTA2) were then used as building blocks for the self-assembly of photothermal-responsive polymer vesicles. The new class of functionalized polymer vesicles inherited the NIR-mediated high photothermal performance of the photothermal agent (PTA). After NIR laser irradiation for 10 min, the temperature of the PTA-Ps aqueous solution was raised to 56 °C. The photothermal properties and bilayer structure of PTA-Ps after laser irradiation were still intact, which demonstrated that they could be applied as a robust platform in photothermal therapy. Besides their photothermal performance, the loading capacity of PTA-Ps was investigated as well. Hydrophobic cargo (Cy7) and hydrophilic cargo (Sulfo-Cy5) were successfully encapsulated in the PTA-Ps. These properties make this new class of functionalized polymer vesicles an interesting platform for synergistic therapy in anticancer treatment.

A photothermal driven chemotherapy for the treatment of metastatic melanoma

Solid tumors are abnormal mass of tissue, which affects the organs based on its malignancy and leads to the dysfunction of the affected organs. The major problem associated with treatment of solid tumors is delivering anticancer therapeutics to the deepest layers/core of the solid tumor. Deposition of excessive extracellular matrix (ECM) hinders the therapeutics to travel towards the core of the tumor. Therefore, conventional anticancer therapeutics can only reduce the tumor size and that also for a limited duration, and tumor recurrence occurs once the therapy is discontinued. Additionally, by the time the cancer is diagnosed, the cancer cells already started affecting the major organs of the body such as lung, liver, spleen, kidney, and brain, due to their ability to metastasize and lung is the primary site for them to be infiltrated. To facilitate the anticancer therapeutics to penetrate the deeper layers of tumor, and to provide concurrent treatment of both the solid tumor and metastasis, we have designed and developed a Bimodal Light Assisted Skin Tumor and Metastasis Treatment (BLAST), which is a combination of photothermal and chemotherapeutic moieties. The BLAST is composed of 2D boron nitride (BN) nanosheet with adsorbed molecules of BCL-2 inhibitor, Navitoclax (NAVI) on its surface, that can breakdown excessive ECM network and thereby facilitate dissociation of the solid tumor. The developed BLAST was evaluated for its ability to penetrate solid tumors using 3D spheroids for the uptake, cytotoxicity, growth inhibition, reactive oxygen species (ROS) detection, penetration, and downregulation of proteins upon laser irradiation. The in vivo therapeutic studies on a skin cancer mice model revealed that the BLAST with and without laser were able to penetrate the solid tumor, reduce tumor volume in mice, dissociate the protein network, and prevent lung metastasis as confirmed by immunohistochemistry and western blot analysis. Post analysis of serum and blood components revealed the safety and efficacy of BLAST in mice. Hence, the developed BLAST holds strong promise in solid tumor treatment and metastasis prevention simultaneously.

A NIR-Activated and Mild-Temperature-Sensitive Nanoplatform with an HSP90 Inhibitor for Combinatory Chemotherapy and Mild Photothermal Therapy in Cancel Cells

Mild photothermal therapy (PTT) shows great potential to treat cancers while avoiding unwanted damage to surrounding normal cells. However, the efficacy of mild PTT is normally moderate because of the low hyperthermia temperature and limited light penetration depth. Chemotherapy has unlimited penetration but often suffers from unsatisfactory efficacy in view of the occurrence of drug resistance, suboptimal drug delivery and release profile. As a result, the combinatory of chemotherapy and mild PTT would integrate their advantages and overcome the shortcomings. Herein, we synthesized an NIR-activatable and mild-temperature-sensitive nanoplatform (BDPII-gel@TSL) composed of temperature-sensitive liposomes (TSL), heat shock protein 90 (HSP90) inhibitor (geldanamycin) and photothermal agent (BDPII), for dual chemotherapy and mild PTT in cancer cells. BDPII, constructed with donor-acceptor moieties, acts as an excellent near-infrared (NIR) photothermal agent (PTA) with a high photothermal conversion efficiency (80.75%). BDPII-containing TSLs efficiently produce a mild hyperthermia effect (42 °C) under laser irradiation (808 nm, 0.5 W cm-2). Importantly, the phase transformation of TSL leads to burst release of geldanamycin from BDPII-gel@TSL, and this contributes to down-regulation of the overexpression of HSP90, ensuring efficient inhibition of cancer cell growth. This research provides a dual-sensitive synergistic therapeutic strategy for cancer cell treatment.

Photothermal Propelling and Pyroelectric Potential-Promoted Cell Internalization of Janus Nanoparticles and Pyroelectrodynamic Tumor Therapy

Cancer phototherapy experiences limitations in tissue diffusion and cell internalization of phototherapeutic agents and dose-dependent side effects. Herein, Janus pyroelectric nanoparticles (NPs) are designed to generate self-powered motion and built-in electric fields to overcome the delivery barriers. Polydopamine (PDA) layers are partially coated on tetragonal BaTiO3 (tBT) NPs to prepare Janus tBT@PDA, and Au NPs are deposited on the PDA caps to obtain Janus tBT@PDA-Au NPs. Near-infrared (NIR) illumination of tBT@PDA-Au builds in situ pyroelectric potentials on NPs, which selectively affect the membrane potential of tumor cells rather than normal cells to enhance tumor cell internalization and produce reactive oxygen species (ROS) for pyroelectric dynamic therapy (PEDT). The asymmetric photothermal effect of the Janus NPs creates thermophoretic force to propel NP motion, which enhances tumor diffusion and cellular uptake of NPs and boosts cytotoxicity and intracellular ROS levels. The inoculation of Au NPs increases the photothermal effect, exhibits larger motion velocities, produces higher pyroelectric potentials, and elevates cellular uptake rates, resulting in significant induction of tumor cell apoptosis, suppression of tumor growth, and extension of animal survival. Thus, the concise design of tBT@PDA-Au/NIR treatment has achieved thermophoretic motion-promoted tissue diffusion, built-in electric field-enhanced cell internalization, and photothermal/PEDT-synergized antitumor efficacy.

NIR-II imaging-guided photothermal cancer therapy combined with enhanced immunogenic death

Photothermal therapy has a remarkable effect on the destruction of tumors. It kills tumor cells by photothermal ablation and induces immunogenic cell death by activating the immune response in tumor tissues. However, inhibition of the tumor immune microenvironment suppresses PTT-induced body-specific anti-tumor immunity. In this study, we designed the GdOF@PDA-HA-R837-hydrogel complex to achieve NIR-II imaging-guided photothermal ablation and enhanced immune response. Due to the doping of Yb and Er elements and the presence of a polydopamine coating, the synthesized nanoparticles enable NIR-II and photoacoustic imaging of tumor tissues, which will help in the integration of multimodal tumor imaging for diagnosis and treatment. Polydopamine is used as a photothermal agent and drug carrier because of its excellent photothermal ability and high drug loading capacity under 808 nm near infrared light. Hyaluronic acid can bind to specific receptors on the surface of cancer cells, allowing nanoparticles to aggregate around the tumor, thus enhancing the targeting ability of nanoparticles. In addition, imiquimod (R837) has been used as an immune response modulator to enhance the immunotherapeutic effect. The presence of a hydrogel enhanced the retention effect of nanoparticles in the tumor. We demonstrate that the combination of photothermal therapy with immune adjuvants effectively induces ICD, which in turn stimulates the activation of specific anti-tumor immunity and enhances the effect of photothermal therapy in vivo.

Injectable nano-composite hydrogels based on hyaluronic acid-chitosan derivatives for simultaneous photothermal-chemo therapy of cancer with anti-inflammatory capacity

Nowadays, the photothermal therapy (PTT) has received widespread attention and research by rapidly killing tumors with local high temperature. However, due to the irregular edges of tumor and the blurred boundary between normal and necrotic tissues, the desirable treatment cannot be achieved by the single PTT, and excessive heat will cause serious inflammation in local tissues. Herein, an injectable composite hydrogel is prepared by the oxidized hyaluronic acid (OHA) and hydroxypropyl chitosan (HPCS) via the imine bonds, which is employed as the delivery substrate for functional substances. In the gel medium, the mesoporous polydopamine (MPDA) nanoparticles are incorporated as the high efficiency photothermal agent and a reservoir of DOX, which can achieve the good photothermal conversion performance and pulsed drug release. Besides, the addition of the curcumin-cyclodextrin host-guest inclusion complex (CUR@NH₂-CD) in the composite hydrogel could reduce the inflammation caused by PTT. The composite hydrogel shows favorable the Hepa1-6 tumor inhibition in vivo by virtue of the comprehensive effect of the admired photothermal efficacy of MPDA, chemotherapy of DOX and anti-inflammatory of CUR. It can be predicted that the composite hydrogel has a broad prospect in the field of comprehensive therapy for tumor.

Polysaccharide-Based Stimulus-Responsive Nanomedicines for Combination Cancer Immunotherapy

Cancer immunotherapy is a promising antitumor approach, whereas nontherapeutic side effects, tumor microenvironment (TME) intricacy, and low tumor immunogenicity limit its therapeutic efficacy. In recent years, combination immunotherapy with other therapies has been proven to considerably increase antitumor efficacy. However, achieving codelivery of the drugs to the tumor site remains a major challenge. Stimulus-responsive nanodelivery systems show controlled drug delivery and precise drug release. Polysaccharides, a family of potential biomaterials, are widely used in the development of stimulus-responsive nanomedicines due to their unique physicochemical properties, biocompatibility, and modifiability. Here, the antitumor activity of polysaccharides and several combined immunotherapy strategies (e.g., immunotherapy combined with chemotherapy, photodynamic therapy, or photothermal therapy) are summarized. More importantly, the recent progress of polysaccharide-based stimulus-responsive nanomedicines for combination cancer immunotherapy is discussed, with the focus on construction of nanomedicine, targeted delivery, drug release, and enhanced antitumor effects. Finally, the limitations and application prospects of this new field are discussed.