Highly reliable, targeted photothermal cancer therapy combined with thermal dosimetry using a near-infrared absorbent

Therapeutic and diagnostic applications of carbon nanotubes in cancer: recent advances and challenges

Carbon nanotubes (CNTs) are allotropes of carbon, composed of carbon atoms forming a tube-like structure. Their high surface area, chemical stability, and rich electronic polyaromatic structure facilitate their drug-carrying capacity. Therefore, CNTs have been intensively explored for several biomedical applications, including as a potential treatment option for cancer. By incorporating smart fabrication strategies, CNTs can be designed to specifically target cancer cells. This targeted drug delivery approach not only maximizes the therapeutic utility of CNTs but also minimizes any potential side effects of free drug molecules. CNTs can also be utilised for photothermal therapy (PTT) which uses photosensitizers to generate reactive oxygen species (ROS) to kill cancer cells, and in immunotherapeutic applications. Regarding the latter, for example, CNT-based formulations can preferentially target intra-tumoural regulatory T-cells. CNTs also act as efficient antigen presenters. With their capabilities for photoacoustic, fluorescent and Raman imaging, CNTs are excellent diagnostic tools as well. Further, metallic nanoparticles, such as gold or silver nanoparticles, are combined with CNTs to create nanobiosensors to measure biological reactions. This review focuses on current knowledge about the theranostic potential of CNT, challenges associated with their large-scale production, their possible side effects and important parameters to consider when exploring their clinical usage.

Nanozymes in cancer immunotherapy: metabolic disruption and therapeutic synergy

Over the past decade, there has been a growing emphasis on investigating the role of immunotherapy in cancer treatment. However, it faces challenges such as limited efficacy, a diminished response rate, and serious adverse effects. Nanozymes, a subset of nanomaterials, demonstrate boundless potential in cancer catalytic therapy for their tunable activity, enhanced stability, and cost-effectiveness. By selectively targeting the metabolic vulnerabilities of tumors, they can effectively intensify the destruction of tumor cells and promote the release of antigenic substances, thereby eliciting immune clearance responses and impeding tumor progression. Combined with other therapies, they synergistically enhance the efficacy of immunotherapy. Hence, a large number of metabolism-regulating nanozymes with synergistic immunotherapeutic effects have been developed. This review summarizes recent advancements in cancer immunotherapy facilitated by nanozymes, focusing on engineering nanozymes to potentiate antitumor immune responses by disturbing tumor metabolism and performing synergistic treatment. The challenges and prospects in this field are outlined. We aim to provide guidance for nanozyme-mediated immunotherapy and pave the way for achieving durable tumor eradication.

DDS-type near-infrared light absorber enables deeper lesion treatment in laser photothermal therapy while avoiding damage to surrounding organs

The efficacy of drug delivery system (DDS)-type near-infrared (NIR) absorbing agents in enhancing laser photothermal therapy is widely acknowledged. Despite the acknowledged efficacy, the therapeutic advantages of photothermal therapy using DDS-type NIR-absorbing agents over simple photothermal therapy without such agents have not been fully elucidated. This study was designed to investigate two primary objectives: firstly, the ability of DDS-type NIR-absorbing agents to induce cell death at greater depths within tumors, and secondly, their capacity to minimize collateral damage to adjacent healthy organs. To investigate these objectives, we employed a combination of indocyanine green lactosome-a DDS-type NIR-absorbing agent-and a precision-controlled laser hyperthermia system. An orthotopic neuroblastoma tumor model was used to closely simulate clinical conditions. The findings revealed that photothermal therapy using the DDS-type NIR-absorbing agent not only facilitates deeper penetration of cell death within tumors but also significantly mitigates thermal damage to surrounding healthy tissues, when compared to simple phototherapy without the agent. Furthermore, the combined treatment significantly prolonged the survival periods of the animals involved. This study is the first to analyze these therapeutic efficacies using quantitative data from an orthotopic tumor animal model and substantiated the potential of DDS-type NIR-absorbing agents to deepen the therapeutic impact of photothermal therapy while safeguarding vital organs, thereby enhancing overall treatment outcomes.

Supramolecular dye nanoassemblies for advanced diagnostics and therapies

Dyes have conventionally been used in medicine for staining cells, tissues, and organelles. Since these compounds are also known as photosensitizers (PSs) which exhibit photoresponsivity upon photon illumination, there is a high desire towards formulating these molecules into nanoparticles (NPs) to achieve improved delivery efficiency and enhanced stability for novel imaging and therapeutic applications. Furthermore, it has been shown that some of the photophysical properties of these molecules can be altered upon NP formation thereby playing a major role in the outcome of their application. In this review, we primarily focus on introducing dye categories, their formulation strategies and how these strategies affect their photophysical properties in the context of photothermal and non-photothermal applications. More specifically, the most recent progress showing the potential of dye supramolecular assemblies in modalities such as photoacoustic and fluorescence imaging, photothermal and photodynamic therapies as well as their employment in photoablation as a novel modality will be outlined. Aside from their photophysical activity, we delve shortly into the emerging application of dyes as drug stabilizing agents where these molecules are used together with aggregator molecules to form stable nanoparticles.

Enhancing Cartilage Metabolism in Rats through a Novel Thermal Stimulation Technique with Photosensitizers

Although the moderate thermal stimulation of articular cartilage exerts chondroprotective effects, it is difficult to effectively heat deep articular cartilage with conventional methods. Photosensitizers increase the ambient temperature using near-infrared (NIR) radiation, which has high tissue permeability. We hypothesized that the intra-articular administration of photosensitizers and NIR irradiation would exert a greater heating effect on articular cartilage. We aimed to evaluate the heating effect of this method on cultured chondrocytes and rat knee cartilage. In vitro, we irradiated a photosensitizer-containing medium with NIR and measured changes in the medium temperature, cytotoxicity, and gene expression of heat shock protein (HSP) 70 and aggrecan (ACAN). In vivo, the knee joints of rats treated with photosensitizers were irradiated with NIR, and changes in intra-articular temperature and gene expression were measured, alongside histological analysis. The results showed that the medium and intra-articular temperature were raised to approximately 40 °C with no apparent disruption to articular cartilage or the immunohistochemically enhanced staining of HSP70 in chondrocytes. The gene expression of HSP70 and ACAN was increased in both cultured and articular cartilage. In summary, this method can safely heat joints and enhance cartilage metabolism by inducing HSP70 expression in articular cartilage. It presents a new hyperthermia therapy with effective cartilage protection.

Current status of controlled onco-therapies based on metal organic frameworks

Despite consecutive efforts devoted to the establishment of innovative therapeutics for cancer control, cancer remains as a primary global public health concern. Achieving controlled release of anti-cancer agents may add great value to the field of oncology that requires the involvement of nanotechnologies. Metal organic frameworks (MOFs) hold great promise in this regard owing to their unique structural properties. MOFs can act as superior candidates for drug delivery given their porous structure and large loading area, and can be prepared into anti-cancer therapeutics by incorporating stimuli-sensitive components into the ligands or nodes of the framework. By combing through chemical and physical features of MOFs favorable for onco-therapeutic applications and current cancer treatment portfolios taking advantages of these characteristics, this review classified MOFs feasible for establishing controlled anti-cancer modalities into 6 categories, outlined the corresponding strategies currently available for each type of MOF, and identified understudied areas and future opportunities towards innovative MOF design for improved or expanded clinical anti-cancer applications.

An Antibody-directed and Immune Response Modifier-augmented Photothermal Therapy Strategy Relieves Aging via Rapid Immune Clearance of Senescent Cells

Cellular senescence is an irreversible and multifaceted process inducing tissue dysfunction and organismal aging, and thus the clearance of senescent cells can prevent or delay the onset of aging-related pathologies. Herein, we developed an augmented photothermal therapy strategy integrated with an antibody against β2-microglobulin (aB2MG) and an immune adjuvant imiquimod (R837) to effectively accelerate senescent cell apoptosis and clearance under a near-infrared light. With this strategy, the designed CroR@aB2MG enables the targeting of senescent cells and the application of photothermal therapy concomitantly, the initiation of immune clearance subsequently, and finally the realization of protective effects against senescence. Our results showed that the photo-induced heating effect caused senescent cells to quickly undergo apoptosis and the synchronous immune response accelerated the clearance of senescent cells in vitro and in vivo. Therefore, this photoactivated speedy clearing strategy may provide an efficient way for the treatment of senescence-related diseases by eliminating senescent cells with biomaterials.

NIR-II emissive donor-acceptor-donor fluorophores for dual fluorescence bioimaging and photothermal therapy applications

Fluorescence bioimaging with near-infrared II (NIR-II) emissive organic fluorophores has proven to be a viable noninvasive diagnostic technique. However, there is still the need for the development of fluorophores that possess increased stability as well as functionalities that impart stimuli responsiveness. Through strategic design, we can synthesize fluorophores that possess not only NIR-II optical profiles but also pH-sensitivity and the ability to generate heat upon irradiation. In this work, we employ a donor-acceptor-donor (D-A-D) design to synthesize a series of NIR-II fluorophores. Here we use thienothiadiazole (TTD) as the acceptor, 3-hexylthiophene (HexT) as the π-spacer and vary the alkyl amine donor units: N,N-dimethylaniline (DMA), phenylpiperidine (Pip), and phenylmorpholine (Morp). Spectroscopic analysis shows that all three derivatives exhibit emission in the NIR-II region with λemimax ranging from 1030 to 1075 nm. Upon irradiation, the fluorophores exhibited noticeable heat generation through non-radiative processes. The ability to generate heat indicates that these fluorophores will act as theranostic (combination therapeutic and diagnostic) agents in which simultaneous visualization and treatment can be performed. Additionally, biosensing capabilities were supported by changes in the absorbance properties while under acidic conditions as a result of protonation of the alkyl amine donor units. The fluorophores also show minimal toxicity in a human mammary cell line and with murine red blood cells. Overall, initial results indicate viable NIR-II materials for multiple biomedical applications.

Theranostics: a multifaceted approach utilizing nano-biomaterials

Biomaterials play a vital role in targeting therapeutics. Over the years, several biomaterials have gained wide attention in the treatment and diagnosis of diseases. Scientists are trying to make more personalized treatments for different diseases, as well as discovering novel single agents that can be used for prognosis, medication administration, and keeping track of how a treatment works. Theranostics based on nano-biomaterials have higher sensitivity and specificity for disease management than conventional techniques. This review provides a concise overview of various biomaterials, including carbon-based materials like fullerenes, graphene, carbon nanotubes (CNTs), and carbon nanofibers, and their involvement in theranostics of different diseases. In addition, the involvement of imaging techniques for theranostics applications was overviewed. Theranostics is an emerging strategy that has great potential for enhancing the accuracy and efficacy of medicinal interventions. Despite the presence of obstacles such as disease heterogeneity, toxicity, reproducibility, uniformity, upscaling production, and regulatory hurdles, the field of medical research and development has great promise due to its ability to provide patients with personalised care, facilitate early identification, and enable focused treatment.

Photothermal therapy of papillary thyroid cancer tumor xenografts with targeted thyroid stimulating hormone receptor antibody functionalized multiwalled carbon nanotubes

Multiwalled carbon nanotubes (MWCNTs) are being widely investigated in multiple biomedical applications including, and not limited to, drug delivery, gene therapy, imaging, biosensing, and tissue engineering. Their large surface area and aspect ratio in addition to their unique structural, optical properties, and thermal conductivity also make them potent candidates for novel hyperthermia therapy. Here we introduce thyroid hormone stimulating receptor (TSHR) antibody–conjugate–MWCNT formulation as an enhanced tumor targeting and light-absorbing device for the photoablation of xenografted BCPAP papillary thyroid cancer tumors. To ensure successful photothermal tumor ablation, we determined three key criteria that needed to be addressed: (1) predictive pre-operational modeling; (2) real-time monitoring of the tumor ablation process; and (3) post-operational follow-up to assess the efficacy and ensure complete response with minimal side effects. A COMSOL-based model of spatial temperature distributions of MWCNTs upon selected laser irradiation of the tumor was prepared to accurately predict the internal tumor temperature. This modeling ensured that 4.5W of total laser power delivered over 2 min, would cause an increase of tumor temperature above 45 ℃, and be needed to completely ablate the tumor while minimizing the damage to neighboring tissues. Experimentally, our temperature monitoring results were in line with our predictive modeling, with effective tumor photoablation leading to a significantly reduced post 5-week tumor recurrence using the TSHR-targeted MWCNTs. Ultimately, the results from this study support a utility for photosensitive biologically modified MWCNTs as a cancer therapeutic modality. Further studies will assist with the transition of photothermal therapy from preclinical studies to clinical evaluations.

Near-Infrared-I to III Absorption and Emission via Core Engineering of Open-Shelled Organic Mixed-Valence Systems

A novel class of agents is developed based on the core engineering of open-shelled organic mixed-valence (MV) systems, which enable tunable absorption and emission across the near infrared (NIR)-I to III biowindow (700-1850 nm) by adjusting the number of central nitrogen oxidation sites and the length of the conjugated bridge. Organic mixed-valence (MV) systems are synthesized through a one-step partial chemical oxidation of starburst oligoarylamines, with varying nitrogen oxidation sites and conjugated bridge lengths, including tris(4-[diethylamino]phenyl)aminen+ (T4EPAn + ), N,N,N',N'-tetrakis(4-[diisobutylamino]phenyl)-1,4-phenylenediaminen+ (TPDAn + ), and N,N,N',N'-tetrakis(4-methoxyphenyl)benzidinen+ (TMPBn + ). The absorption wavelength of the MV systems redshifted clearly as the number of central nitrogen oxidation sites increased or the conjugated bridge length is prolonged. T4EPAn + with one central nitrogen oxidation site exhibits fluorescence emission in the range of 900-1400 nm, while TPDAn + with two central nitrogen oxidation sites demonstrate strong heat generation capabilities. Additionally, the absorption peak of TMPBn + with a biphenyl conjugated bridge reaches up to 1610 nm. Especially, these MV systems are highly stable for biological applications due to their high steric hindrance and hyperconjugation effect. These characteristics make MV systems promising candidates for constructing NIR-I/II/III emitters and photothermal agents, representing a significant advance toward developing the next generation of NIR-I to III agents.

Dendritic Cell Vaccines: A Shift from Conventional Approach to New Generations

In the emerging era of cancer immunotherapy, immune checkpoint blockades (ICBs) and adoptive cell transfer therapies (ACTs) have gained significant attention. However, their therapeutic efficacies are limited due to the presence of cold type tumors, immunosuppressive tumor microenvironment, and immune-related side effects. On the other hand, dendritic cell (DC)-based vaccines have been suggested as a new cancer immunotherapy regimen that can address the limitations encountered by ICBs and ACTs. Despite the success of the first generation of DC-based vaccines, represented by the first FDA-approved DC-based therapeutic cancer vaccine Provenge, several challenges remain unsolved. Therefore, new DC vaccine strategies have been actively investigated. This review addresses the limitations of the currently most adopted classical DC vaccine and evaluates new generations of DC vaccines in detail, including biomaterial-based, immunogenic cell death-inducing, mRNA-pulsed, DC small extracellular vesicle (sEV)-based, and tumor sEV-based DC vaccines. These innovative DC vaccines are envisioned to provide a significant breakthrough in cancer immunotherapy landscape and are expected to be supported by further preclinical and clinical studies.

Mitochondrial DNA-targeted therapy: A novel approach to combat cancer

Mitochondrial DNA (mtDNA) encodes proteins and RNAs that are essential for mitochondrial function and cellular homeostasis, and participates in important processes of cellular bioenergetics and metabolism. Alterations in mtDNA are associated with various diseases, especially cancers, and are considered as biomarkers for some types of tumors. Moreover, mtDNA alterations have been found to affect the proliferation, progression and metastasis of cancer cells, as well as their interactions with the immune system and the tumor microenvironment (TME). The important role of mtDNA in cancer development makes it a significant target for cancer treatment. In recent years, many novel therapeutic methods targeting mtDNA have emerged. In this study, we first discussed how cancerogenesis is triggered by mtDNA mutations, including alterations in gene copy number, aberrant gene expression and epigenetic modifications. Then, we described in detail the mechanisms underlying the interactions between mtDNA and the extramitochondrial environment, which are crucial for understanding the efficacy and safety of mtDNA-targeted therapy. Next, we provided a comprehensive overview of the recent progress in cancer therapy strategies that target mtDNA. We classified them into two categories based on their mechanisms of action: indirect and direct targeting strategies. Indirect targeting strategies aimed to induce mtDNA damage and dysfunction by modulating pathways that are involved in mtDNA stability and integrity, while direct targeting strategies utilized molecules that can selectively bind to or cleave mtDNA to achieve the therapeutic efficacy. This study highlights the importance of mtDNA-targeted therapy in cancer treatment, and will provide insights for future research and development of targeted drugs and therapeutic strategies.

Folate targeting self-limiting hyperthermic nanoparticles for controlled photothermal therapy

Photothermal therapy utilizes photothermal agents and the use of nanoparticle agents is deemed advantageous for multiple reasons. Common nano-photothermal agents normally have high conversion efficiencies and heating rates, but bulk temperature measurement methods do not adequately represent the nanoscale temperatures of these nanoheaters. Herein, we report on the fabrication of self-limiting hyperthermic nanoparticles that can simultaneously photoinduce hyperthermia and report back temperature ratiometrically. The synthesized nanoparticles utilize a plasmonic core to achieve the photoinduced hyperthermic property and fluorescent FRET pairs entrapped in a silica shell to impart the ratiometric temperature sensing ability. The studies demonstrate the photoinduced hyperthermia with simultaneous temperature measurement using these particles and show that the particles can achieve a conversion efficiency of 19.5% despite the shell architecture. These folate-functionalized self-limiting photothermal agents are also used to demonstrate targeted photoinduced hyperthermia in a HeLa cell model.

Biomedical applications of MnO2 nanomaterials as nanozyme-based theranostics

Manganese dioxide (MnO₂) nanoenzymes/nanozymes (MnO₂-NEs) are 1-100 nm nanomaterials that mimic catalytic, oxidative, peroxidase, and superoxide dismutase activities. The oxidative-like activity of MnO₂-NEs makes them suitable for developing effective and low-cost colorimetric detection assays of biomolecules. Interestingly, MnO₂-NEs also demonstrate scavenging properties against reactive oxygen species (ROS) in various pathological conditions. In addition, due to the decomposition of MnO₂-NEs in the tumor microenvironment (TME) and the production of Mn²⁺, they can act as a contrast agent for improving clinical imaging diagnostics. MnO₂-NEs also can use as an in situ oxygen production system in TME, thereby overcoming hypoxic conditions and their consequences in the progression of cancer. Furthermore, MnO₂-NEs as a shell and coating make the nanosystems smart and, therefore, in combination with other nanomaterials, the MnO₂-NEs can be used as an intelligent nanocarrier for delivering drugs, photosensitizers, and sonosensitizers in vivo. Moreover, these capabilities make MnO₂-NEs a promising candidate for the detection and treatment of different human diseases such as cancer, metabolic, infectious, and inflammatory pathological conditions. MnO₂-NEs also have ROS-scavenging and anti-bacterial properties against Gram-positive and Gram-negative bacterial strains, which make them suitable for wound healing applications. Given the importance of nanomaterials and their potential applications in biomedicine, this review aimed to discuss the biochemical properties and the theranostic roles of MnO₂-NEs and recent advances in their use in colorimetric detection assays of biomolecules, diagnostic imaging, drug delivery, and combinatorial therapy applications. Finally, the challenges of MnO₂-NEs applications in biomedicine will be discussed.

Dual Targeted Delivery of Liposomal Hybrid Gold Nano-Assembly for Enhanced Photothermal Therapy against Lung Carcinomas

The delivery and accumulation of therapeutic drugs into cancer cells without affecting healthy cells are a major challenge for antitumor therapy. Here, we report the synthesis of a liposomal hybrid gold nano-assembly with enhanced photothermal activity for lung cancer treatment. The core components of the nano-assembly include gold nanorods coated with a mesoporous silica shell that offers an excellent drug-loading surface for encapsulation of doxorubicin. To enhance the photothermal capacity of nano-assembly, IR 780 dye was loaded inside a thermo-sensitive liposome, and then, the core nano-assembly was wrapped within the liposome, and GE-11 peptide and folic acid were conjugated onto the surface of the liposome to give the final nano-assembly [(GM@Dox) LI]-PF. The dual targeting approach of [(GM@Dox) LI]-PF leads to enhanced cellular uptake and improves the accumulation of nano-assemblies in cancer cells that overexpress the epidermal growth factor receptor and folate. The exposure of near-infrared laser irradiation can trigger photothermal-induced structural disruption of the nano-assembly, which allows for the precise and controllable release of Dox at targeted sites. Additionally, chemo-photothermal therapy was shown to be 11 times more effective in cancer cell treatment when compared to Dox alone. Our systematic study suggests that the nano-assemblies facilitate the cancer cells undergoing apoptosis via an intrinsic mitochondrial pathway that can be directly triggered by the chemo-photothermal treatment. This study offers an appealing candidate that holds great promise for synergistic cancer treatment.

Macrocycle-Based Covalent Organic Frameworks

Macrocycles with well-defined cavities and the ability to undergo supramolecular interactions are classical materials that have played an essential role in materials science. However, one of the most substantial barriers limiting the utilization of macrocycles is their aggregation, which blocks the active regions. Among many attempted strategies to prevent such aggregation, installing macrocycles into covalent organic frameworks (COFs), which are porous and stable reticular networks, has emerged as an ideal solution. The resulting macrocycle-based COFs (M-COFs) preserve the macrocycles' unique activities, enabling applications in various fields such as single-atom catalysis, adsorption/separation, optoelectronics, phototherapy, and structural design of forming single-layered or mechanically interlocked COFs. The resulting properties are unmatchable by any combination of macrocycles with other substrates, opening a new chapter in advanced materials. This review focuses on the latest progress in the concepts, synthesis, properties, and applications of M-COFs, and presents an in-depth outlook on the challenges and opportunities in this emerging field.

Development of "smart" drug delivery systems for chemo/PDT synergistic treatment

Although chemotherapy and photodynamic therapy (PDT) have been developed for fighting cancer, the complex and heterogeneous nature of tumors makes it difficult for a single therapy to completely inhibit tumor growth. In order to reduce multidrug resistance of cancer cells to chemotherapeutic drugs and overcome low PDT efficiency in the hypoxic tumor microenvironment (TME), chemo/PDT synergistic treatment has received much attention in recent years. Depending on the characteristic signals of TME, various drug delivery systems can be constructed to target tumors and improve the therapeutic efficacy and the pharmacokinetic profile of anticancer drugs. This review highlights the synergistic strategies, treatment protocols, and design of chemo/PDT co-therapy in recent years to explore its scope and limitations. Taking advantage of stimuli-responsive materials and active cancer-targeting agents, cancer-targeting synergistic therapy is presented and discussed, providing ideas and suggestions for the construction of chemo/PDT co-therapy "smart" nanocarriers.

A Multilayered Mesoporous Gold Nanoarchitecture for Ultraeffective Near-Infrared Light-Controlled Chemo/Photothermal Therapy for Cancer Guided by SERS Imaging

Surface-enhanced Raman scattering (SERS) imaging has emerged as a promising tool for guided cancer diagnosis and synergistic therapies, such as combined chemotherapy and photothermal therapy (chemo-PTT). Yet, existing therapeutic agents often suffer from low SERS sensitivity, insufficient photothermal conversion, or/and limited drug loading capacity. Herein, a multifunctional theragnostic nanoplatform consisting of mesoporous silica-coated gold nanostar with a cyclic Arg-Gly-Asp (RGD)-coated gold nanocluster shell (named RGD-pAS@AuNC) is reported that exhibits multiple "hot spots" for pronouncedly enhanced SERS signals and improved near-infrared (NIR)-induced photothermal conversion efficiency (85.5%), with a large capacity for high doxorubicin (DOX) loading efficiency (34.1%, named RGD/DOX-pAS@AuNC) and effective NIR-triggered DOX release. This nanoplatform shows excellent performance in xenograft tumor model of HeLa cell targeting, negligible cytotoxicity, and good stability both in vitro and in vivo. By SERS imaging, the optimal temporal distribution of injected RGD/DOX-pAS@AuNCs at the tumor site is identified for NIR-triggered local chemo-PTT toward the tumor, achieving ultraeffective therapy in tumor cells and tumor-bearing mouse model with 5 min of NIR irradiation (0.5 W cm^-2 ). This work offers a promising approach to employing SERS imaging for effective noninvasive tumor treatment by on-site triggered chemo-PTT.

Impact of Green Gold Nanoparticle Coating on Internalization, Trafficking, and Efficiency for Photothermal Therapy of Skin Cancer

Skin cancer is a global health issue and mainly composed of melanoma and nonmelanoma cancers. For the first clinical proof of concept on humans, we decided to study good prognosis skin cancers, i.e., carcinoma basal cell. In UE, the first-line treatment remains surgical resection, healing most of the tumors, but presents aesthetic disadvantages with a high reoccurrence rate on exposed areas. Moreover, the therapeutic indications could extend to melanoma and metastasis, which is a different medical strategy that could combine this treatment. Indeed, patients with late-stage melanoma are in a therapeutic impasse, despite recent targeted and immunological therapies. Photothermal therapy using gold nanoparticles is the subject of many investigations due to their strong potential to treat cancers by physical, thermal destruction. We developed gold nanoparticles synthesized by green chemistry (gGNPs), using endemic plant extract from Reunion Island, which have previously showed their efficiency at a preclinical stage. Here, we demonstrate that these gGNPs are less cytotoxic than gold nanoparticles synthesized by Turkevich's method. Furthermore, our work describes the optimization of gGNP coating and stabilization, also taking into consideration the gGNP path in cells (endocytosis, intracellular trafficking, and exocytosis), their specificity toward cancerous cells, their cytotoxicity, and their in vivo efficiency. Finally, based on the metabolic switch of cancerous cells overexpressing Glut transporters in skin cancers, we demonstrated that glucose-stabilized gGNP (gGNP@G) enables a quick internalization, fourfold higher in cancerous cells in contrast to healthy cells with no side cytotoxicity, which is particularly relevant to target and treat cancer.

Virus-like nanoparticles as a theranostic platform for cancer

Virus-like nanoparticles (VLPs) are natural polymer-based nanomaterials that mimic viral structures through the hierarchical assembly of viral coat proteins, while lacking viral genomes. VLPs have received enormous attention in a wide range of nanotechnology-based medical diagnostics and therapies, including cancer therapy, imaging, and theranostics. VLPs are biocompatible and biodegradable and have a uniform structure and controllable assembly. They can encapsulate a wide range of therapeutic and diagnostic agents, and can be genetically or chemically modified. These properties have led to sophisticated multifunctional theranostic platforms. This article reviews the current progress in developing and applying engineered VLPs for molecular imaging, drug delivery, and multifunctional theranostics in cancer research.

Enhancing Photothermal Therapy Efficacy by In Situ Self-Assembly in Glioma

The residence time of some small molecular imaging and therapeutic agents in tumor tissue is short and the molecules can be easily dispersed, which decreases treatment efficacy. Therefore, methods that enhance oncotherapy performance are of significant importance. Here, we report an in situ self-assembly strategy aimed at enhancing the photothermal therapy of glioblastomas. The probe, ICG-PEP-c(RGD)fk, consisted of a glutathione-reactive self-assembling polypeptide as the skeleton, indocyanine green (ICG) as a theranostic agent, and cyclic Arg-Gly-Asp [c(RGD)fk] peptides as the targeting group. ICG-PEP-c(RGD)fk was synthesized and found to be assembled in the glutathione environment at 9.446 μM in vitro. Human glioblastoma cell line U87MG-luc with high integrin αvβ3 expression was applied to invivo experiments. ICG-PEP-c(RGD)fk provided clearer tumor imaging and had a tumor retention time of 6.12 times longer than that of ICG-c(RGD)fk. In therapeutic experiments, ICG-PEP-c(RGD)fk significantly suppressed glioblastoma growth and the tumor volume was 2.61 times smaller than in the ICG-c(RGD)fk group at the end of the observation period. Moreover, the median survival time of ICG-PEP-c(RGD)fk group was significantly improved by 2.78 times compared with that of the control group. In conclusion, glutathione-reactive self-assembling peptides are capable of increasing the tumor retention time and improving the photothermal therapeutic effect. The in situ self-assembly strategy is a potential and feasible method to enhance oncotherapy.

Current status of Cancer Nanotheranostics: Emerging strategies for cancer management

Cancer diagnosis and management have been a slow-evolving area in medical science. Conventional therapies have by far proved to have various limitations. Also, the concept of immunotherapy which was thought to revolutionize the management of cancer has presented its range of drawbacks. To overcome these limitations nanoparticulate-derived diagnostic and therapeutic strategies are emerging. These nanomaterials are to be explored as they serve as a prospect for cancer theranostics. Nanoparticles have a significant yet unclear role in screening as well as therapy of cancer. However, nanogels and Photodynamic therapy is one such approach to be developed in cancer theranostics. Photoactive cancer theranostics is a vivid area that might prove to help manage cancer. Also, the utilization of the quantum dots as a diagnostic tool and to selectively kill cancer cells, especially in CNS tumors. Additionally, the redox-sensitive micelles targeting the tumor microenvironment of the cancer are also an important theranostic tool. This review focuses on exploring various agents that are currently being studied or can further be studied as cancer theranostics.

Terminalia chebula Polyphenol and Near-Infrared Dye-Loaded Poly(lactic acid) Nanoparticles for Imaging and Photothermal Therapy of Cancer Cells

Photothermal/photodynamic therapies (PTT/PDT) are multimodal approaches employing near-infrared (NIR) light-responsive photosensitizers for cancer treatment. In the current study, IR-775, a hydrophobic photosensitizer, was used in combination with a polyphenols (p)-rich ethyl acetate extract from Terminalia chebula to treat cancer. IR-775 dye and polyphenols were encapsulated in a poly(lactic acid) polymeric nanosystem (PpIR NPs) to increase the cell bioavailability. The hydrodynamic diameter of PpIR NPs is 142.6 ± 2 nm and exhibited physical stability. The nanosystem showed enhanced cellular uptake in a lung cancer cell line (A549). Cell cytotoxicity results indicate that PpIR NPs showed more than 82.46 ± 3% cell death upon NIR light treatment compared to the control groups. Both PDT and PTT generate reactive oxygen species (ROS) and cause hyperthermia, thereby enhancing cancer cell death. Qualitative and quantitative analyses have depicted that PpIR NPs with NIR light irradiation have decreased protein expression of HSP70 and PARP, and increased γ-H2AX, which collectively lead to cell death. After NIR light irradiation, the relative gene expression patterns of HSP70 and CDK2Na were also downregulated. Further, PpIR NPs uptake has been studied in 3D cells and in ovo bioimaging in zebrafish models. In conclusion, the PpIR NPs show good cancer cell cytotoxicity and present a potential nanosystem for bioimaging.

Temperature-controlled laser thermal therapy system using a newly developed laparoscopic system equipped with an ultra-compact thermographic camera

Laser thermal therapy is one of the treatments for malignant tumors. We developed a thermal endoscope using an ultra-compact thermo-sensor and established a new laparoscopic laser thermal therapy system to heat cancer tissue at an appropriate temperature, focusing on the fact that thermographic cameras are capable of two-dimensional temperature mapping. Hepatocellular carcinoma (N1S1) cells were implanted into the livers of Sprague-Dawley rats (n = 13) to create orthotopic hepatocellular carcinoma. Six of the rats underwent laparoscopic laser thermotherapy (70 °C, 5 min) using the newly developed system, and the others underwent laparoscopic insertion only. Lesion volume measurement and histological evaluation were performed in all of the rats. The laparoscopic laser thermal therapy system provided stable temperature control. When a temperature of 70 °C was used for the set temperature, the temperature of the target cancer was maintained within the range of 68-72 °C for 93.2% of the irradiation time (5 min). The median volume of the tumors that were thermally treated was significantly smaller than that of the untreated tumors. The newly developed laparoscopic laser thermal therapy system was capable of maintaining the temperature of the tumor surface at any desired temperature and was proven to be effective in treatment of the rat hepatocellular carcinoma model.

Theranostics Using Indocyanine Green Lactosomes

Lactosomes™ are biocompatible nanoparticles that can be used for cancer tissue imaging and drug delivery. Lactosomes are polymeric micelles formed by the self-assembly of biodegradable amphiphilic block copolymers composed of hydrophilic polysarcosine and hydrophobic poly-L-lactic acid chains. The particle size can be controlled in the range of 20 to 100 nm. Lactosomes can also be loaded with hydrophobic imaging probes and photosensitizers, such as indocyanine green. Indocyanine green-loaded lactosomes are stable for long-term circulation in the blood, allowing for accumulation in cancer tissues. Such lactosomes function as a photosensitizer, which simultaneously enables fluorescence diagnosis and photodynamic therapy. This review provides an overview of lactosomes with respect to molecular design, accumulation in cancer tissue, and theranostics applications. The use of lactosomes can facilitate the treatment of cancers in unresectable tissues, such as glioblastoma and head and neck cancers, which can lead to improved quality of life for patients with recurrent and unresectable cancers. We conclude by describing some outstanding questions and future directions for cancer theranostics with respect to clinical applications.

Ferrocene and glucose oxidase-installed multifunctional hydrogel reactors for local cancer therapy

A hyaluronic acid (HA)-based one-pot hydrogel reactor with single syringe injection and immediate gelation was developed for starvation therapy (ST), chemodynamic therapy (CDT), ferroptosis, and photothermal therapy (PTT) against breast cancer. A rheologically tuned hydrogel network, composed of HA-phenylboronic acid (HP) and HA-dopamine (HD), was designed by introducing a boronate ester linkage (phenylboronic acid-dopamine interaction) and polydopamine bond (pH control). Ferrocene (Fc)-conjugated HP (Fc-HP) was synthesized to achieve ferroptosis, Fenton reaction-involved toxic hydroxyl radical (^•OH) generation, and photothermal ablation in cancer therapy. Glucose oxidase (GOx) was entrapped in the pH-modulated Fc-HP (Fc-HP°)/HD hydrogel network for converting intracellular glucose to H₂O₂ to enable its own supply. The GOx/Fc combination-installed hydrogel reactor system can provide sustained ST/CDT/PTT functions along with ferroptosis. Injection of Fc-HP°/HD/GOx hydrogel with single-syringe injectability, shear-thinning feature, and self-healing capability offered a slow biodegradation rate and high safety profiles. Peritumorally injected Fc-HP°/HD/GOx hydrogel also efficiently suppressed the growth of breast cancer based on multifunctional therapeutic approaches with reduced dosing frequency. Hyperthermia induced by near-infrared (NIR) laser absorption may amplify the therapeutic effects of free radicals. It is expected that this Fc-HP°/HD/GOx hydrogel system can be applied to local cancer therapy with high efficacy and safety profiles.

New Polymeric Composites Based on Two-Dimensional Nanomaterials for Biomedical Applications

The constant evolution and advancement of the biomedical field requires robust and innovative research. Two-dimensional nanomaterials are an emerging class of materials that have risen the attention of the scientific community. Their unique properties, such as high surface-to-volume ratio, easy functionalization, photothermal conversion, among others, make them highly versatile for a plethora of applications ranging from energy storage, optoelectronics, to biomedical applications. Recent works have proven the efficiency of 2D nanomaterials for cancer photothermal therapy (PTT), drug delivery, tissue engineering, and biosensing. Combining these materials with hydrogels and scaffolds can enhance their biocompatibility and improve treatment for a variety of diseases/injuries. However, given that the use of two-dimensional nanomaterials-based polymeric composites for biomedical applications is a very recent subject, there is a lot of scattered information. Hence, this review gathers the most recent works employing these polymeric composites for biomedical applications, providing the reader with a general overview of their potential.

Biodegradable Protein-Stabilized Inorganic Nanoassemblies for Photothermal Radiotherapy of Hepatoma Cells

Inorganic nanomaterials require optimal engineering to retain their functionality yet can also biodegrade within physiological conditions to avoid chronic accumulation in their native form. In this work, we have developed gelatin-stabilized iron oxide nanoclusters having a primary crystallite size of ∼10 nm and surface-functionalized with indocyanine green (ICG)-bound albumin-stabilized gold nanoclusters (Prot-IONs). The Prot-IONs are designed to undergo disintegration in an acidic microenvironment of tumor in the presence of proteolytic enzymes within 72 h. These nanoassemblies demonstrate bio- and hemocompatibility and show significant photothermal efficiency due to strong near infrared absorption contributed by ICG. The surface gold nanoclusters could efficiently sensitize hepatoma cells to γ-irradiation with substantial cytoskeletal and nuclear damage. Sequential irradiation of Prot-ION-treated cancer cells with near infrared (NIR) laser (λ = 750 nm) and γ-irradiation could cause ∼90% cell death compared to single treatment groups at a lower dose of nanoparticles. The superparamagnetic nature of Prot-IONs imparted significant relaxivity (∼225 mM-1 s-1) for T2-weighted magnetic resonance imaging. Additionally, they could also be engaged as photoacoustic and NIR imaging contrast agents. This work demonstrates bioeliminable inorganic nanoassemblies with significant theranostic potential.

Nucleus Near-Infrared (nNIR) Irradiation of Single A549 Cells Induces DNA Damage and Activates EGFR Leading to Mitochondrial Fission

There has been great interest in identifying the biological substrate for light-cell interaction and their relations to cancer treatment. In this study, a near-infrared (NIR) laser is focused into the nucleus (nNIR) or cytoplasm (cNIR) of a single living cell by a high numerical aperture condenser to dissect the novel role of cell nucleus in mediating NIR effects on mitochondrial dynamics of A549 non-small cell lung cancer cells. Our analysis showed that nNIR, but not cNIR, triggered mitochondrial fission in 10 min. In contrast, the fission/fusion balance of mitochondria directly exposed to cNIR does not change. While the same phenomenon is also triggered by single molecular interactions between epidermal growth factor (EGF) and its receptor EGFR, pharmacological studies with cetuximab, PD153035, and caffeine suggest EGF signaling crosstalk to DNA damaging response to mediate rapid mitochondrial fission as a result of nNIR irradiation. These results suggest that nuclear DNA integrity is a novel biological target for cellular response to NIR.

Applications of the ROS-Responsive Thioketal Linker for the Production of Smart Nanomedicines

Reactive oxygen species (ROS)-sensitive drug delivery systems (DDS) specifically responding to altered levels of ROS in the pathological microenvironment have emerged as an effective means to enhance the pharmaceutical efficacy of conventional nanomedicines, while simultaneously reducing side effects. In particular, the use of the biocompatible, biodegradable, and non-toxic ROS-responsive thioketal (TK) functional group in the design of smart DDS has grown exponentially in recent years. In the design of TK-based DDS, different technological uses of TK have been proposed to overcome the major limitations of conventional DDS counterparts including uncontrolled drug release and off-target effects. This review will focus on the different technological uses of TK-based biomaterials in smart nanomedicines by using it as a linker to connect a drug on the surface of nanoparticles, form prodrugs, as a core component of the DDS to directly control its structure, to control the opening of drug-releasing gates or to change the conformation of the nano-systems. A comprehensive view of the various uses of TK may allow researchers to exploit this reactive linker more consciously while designing nanomedicines to be more effective with improved disease-targeting ability, providing novel therapeutic opportunities in the treatment of many diseases.

Simultaneous nanocarrier-mediated delivery of siRNAs and chemotherapeutic agents in cancer therapy and diagnosis: Recent advances

Recently, investigations have revealed that RNA interference (RNAi) has a remarkable potential to decrease cancer burden by downregulating genes. Among various RNAi molecules, small interfering RNA (siRNA) has been more attractive for this goal and is able to silence a target pathological path and promote the degradation of a certain mRNA, resulting in either gain or loss of function of proteins. Moreover, therapeutic siRNAs have exhibited low side effects compared to other therapeutic molecular candidates. Nevertheless, siRNA delivery has its own limitations including quick degradation in circulation, ineffective internalization and low passive uptake by cells, possible toxicity against off-target sites, and inducing unfavorable immune responses. Therefore, delivery tools must be able to specifically direct siRNAs to their target locations without inflicting detrimental effects on other sites. To conquer the mentioned problems, nanocarrier-mediated delivery of siRNAs, using inorganic nanoparticles (NPs), polymers, and lipids, has been developed as a biocompatible delivery approach. In this review, we have discussed recent advances in the siRNA delivery methods that employ nanoparticles, lipids, and polymers, as well as the inorganic-based co-delivery systems used to deliver siRNAs and anticancer agents to target cells.

Alginate-enabled green synthesis of S/Ag1.93S nanoparticles, their photothermal property and in-vitro assessment of their anti-skin-cancer effects augmented by a NIR laser

We report herein the design and synthesis of colloidally-stable S/Ag_1.93S nanoparticles, their photothermal conversion properties and in vitro cytotoxicity toward A431 skin cancer cells under the excitation of a minimally-invasive 980 nm near-infrared (NIR) laser. Micron-sized S particles were first synthesized via acidifying Na₂S₂O₃ using biocompatible sodium alginate as a surfactant. In the presence of AgNO₃ and under rapid microwave-induced heating, alginate reduced AgNO₃ to nascent Ag which reacted with molten S in situ to S/Ag_1.93S nanoparticles. The nanoparticles were characterized using a combination of X-ray diffraction, electron microscopies, elemental analysis, zeta-potential analysis and UV-VIS-NIR spectroscopy. The average particles size was controlled between 40 and 60 nm by fixing the mole ratio of Ag⁺:S₂O₃^2-. When excited by a 980 nm laser, S/Ag_1.93S nanoparticles (~40 nm) produced with the least amount of AgNO₃ exhibited a respectable photothermal conversion efficiency of circa 62% with the test aqueous solution heated to a hyperthermia-inducing 52 °C in 15 min. At 0.7 W/cm², the viability of A431 skin cancer cells incubated with 7.0 ± 0.2 μg/mL of S/Ag_1.93S nanoparticles reduced to 14 ± 0.6%, while an A431 cell control maintained an 80% cell viability. These results suggested that S/Ag_1.93S nanoparticles may have good potential in reducing metastatic skin carcinoma.

(Rose Bengal)/(Eosin Yellow)-Gold-Polypyrrole Hybrids: A Design for Dual Photo-Active Nano-System with Ultra-High Loading Capacity

Purpose

Enhancement of the photodynamic/photothermal efficiency of two water-soluble dyes, rose bengal (RB) and eosin yellow (EY), via conjugation to a polymeric nano-system gold-polypyrrole nanoparticle (AuPpy NPs).

Methodology

A multi-step synthesis method and an in situ one-pot synthesis method were used. Loading percentage, particle size, zeta potential, morphology, UV-Vis-NIR spectrophotometry and in vitro photothermal activity were measured. Then, both hybrid nanocomposites were examined for their cytotoxicity and photocytotoxicity on HepG2 cell line as a model for cancer cells.

Results

Dyes loaded in the traditional multi-step method did not exceed 9% w/w, while in the one-pot synthesis method they reached ~67% w/w and ~75% w/w for EY-AuPpy NPs and RB-AuPpy NPs, respectively. UV-Vis-NIR spectrophotometry showed that both nano-systems exhibited intense absorption in the NIR region. The mean size of the nanoparticles was ~31.5 nm (RB-AuPpy NPs) and ~33.6 nm (EY-AuPpy NPs) with zeta potential values of −26.5 mV and −33 mV, respectively. TEM imaging revealed the morphology of both hybrids, showing ultra-nano spherical-shaped gold cores in the case of RB-AuPpy NPs, and different shapes of larger gold cores in the case of EY-AuPpy NPs, both embedded in the polymer film. Conjugation to AuPpy was found to significantly reduce the dark cytotoxicity of both RB and EY, preserving the photocytotoxicity of EY and enhancing the photocytotoxicity of RB.

Conclusion

Gold-polypyrrole nanoparticles represent an effective delivery system to improve the photodynamic and photothermal properties of RB and EY. The in situ one-pot synthesis method provided a means to greatly increase the loading capacity of AuPpy NPs. While both hybrid nanocomposites exhibited greatly diminished dark cytotoxicity, RB-AuPpy NPs showed significantly enhanced photocytotoxicity compared to the free dyes. This pattern enables the safe use of both dyes in high concentrations with sustained action, reducing dose frequency and side effects.

Numerical Simulation of Enhancement of Superficial Tumor Laser Hyperthermia with Silicon Nanoparticles

Biodegradable and low-toxic silicon nanoparticles (SiNPs) have potential in different biomedical applications. Previous experimental studies revealed the efficiency of some types of SiNPs in tumor hyperthermia. To analyse the feasibility of employing SiNPs produced by the laser ablation of silicon nanowire arrays in water and ethanol as agents for laser tumor hyperthermia, we numerically simulated effects of heating a millimeter-size nodal basal-cell carcinoma with embedded nanoparticles by continuous-wave laser radiation at 633 nm. Based on scanning electron microscopy data for the synthesized SiNPs size distributions, we used Mie theory to calculate their optical properties and carried out Monte Carlo simulations of light absorption inside the tumor, with and without the embedded nanoparticles, followed by an evaluation of local temperature increase based on the bioheat transfer equation. Given the same mass concentration, SiNPs obtained by the laser ablation of silicon nanowires in ethanol (eSiNPs) are characterized by smaller absorption and scattering coefficients compared to those synthesized in water (wSiNPs). In contrast, wSiNPs embedded in the tumor provide a lower overall temperature increase than eSiNPs due to the effect of shielding the laser irradiation by the highly absorbing wSiNPs-containing region at the top of the tumor. Effective tumor hyperthermia (temperature increase above 42 °C) can be performed with eSiNPs at nanoparticle mass concentrations of 3 mg/mL and higher, provided that the neighboring healthy tissues remain underheated at the applied irradiation power. The use of a laser beam with the diameter fitting the size of the tumor allows to obtain a higher temperature contrast between the tumor and surrounding normal tissues compared to the case when the beam diameter exceeds the tumor size at the comparable power.

Assessing the parameters modulating optical losses of iron oxide nanoparticles under near infrared irradiation

Heating mediated by iron oxide nanoparticles subjected to near infrared irradiation has recently gained lots of interest. The high optical loss values reported in combination with the optical technologies already existing in current clinical practices, have made optical heating mediated by iron oxide nanoparticles an attractive choice for treating internal or skin tumors. However, the identification of the relevant parameters and the influence of methodologies for quantifying the optical losses released by iron oxide nanoparticles are not fully clear. Here, we report on a systematic study of different intrinsic (size, shape, crystallinity, and iron oxidation state) and extrinsic (aggregation, concentration, intracellular environment and irradiation conditions) parameters involved in the photothermal conversion of iron oxide nanoparticles under near infrared irradiation. We have probed the temperature increments to determine the specific loss power of iron oxide nanoparticles with different sizes and shapes dispersed in colloidal suspensions or inside live breast cancer cells. Our results underline the relevance of crystal surface defects, aggregation, concentration, magnetite abundance, excitation wavelength and density power on the modulation of the photothermal conversion. Contrary to plasmonic or magnetic losses, no significant influence of nanoparticle size nor shape was observed on the optical losses released by the studied iron oxide nanoparticles. Interestingly, no significant differences of measured temperature increments and specific loss power values were either observed when nanoparticles were inside live cells or in colloidal dispersion. Our findings highlight the advantages of optical heat losses released by iron oxide nanoparticles for therapeutic applications.

Determination of the Wavelength-Dependent Photothermal Conversion Efficiency of Photosensitizers for Photothermal Therapy: Application to Ag2S-Glutathione Quantum Dots

Nanoparticles have become popular photosensitizers for photothermal therapy (PTT), as they can be targeted to specific cancer tissues and deliver a chemotherapeutic drug, providing a multimodal therapeutic approach. Photothermal conversion efficiency of nanoparticles is critical in the assessment of their therapeutic use in PTT. We describe an accurate calorimetric method for the determination of the photothermal conversion efficiency of nanoparticles in solution. A tightly focused laser beam was used to irradiate a cuvette containing a solution of silver sulfide-glutathione quantum dots (Ag₂S-GSH QDs), and the maximum steady-state temperature rise was measured with an infrared camera. The data were analyzed using two different photothermal conversion efficiencies, the intrinsic and external conversion efficiencies, to relate the induced heating power of the nanoparticles to the absorbed and incident optical powers, respectively. Measurements with a tunable Ti³⁺:sapphire laser showed that the intrinsic photothermal conversion efficiency of Ag₂S-GSH QDs exceeded 91% over the 720-810 nm wavelength range. The method was also used to analyze poly(acrylic acid)-coated superparamagnetic iron oxide nanoparticles (PAA/SPIONs), and the intrinsic photothermal conversion efficiency was determined to be 83.4% at 810 nm. This approach is useful for the evaluation of various potential nanoparticles for photothermal therapy applications.

Latest Innovations and Nanotechnologies with Curcumin as a Nature-Inspired Photosensitizer Applied in the Photodynamic Therapy of Cancer

In the context of the high incidence of cancer worldwide, state-of-the-art photodynamic therapy (PDT) has entered as a usual protocol of attempting to eradicate cancer as a minimally invasive procedure, along with pharmacological resources and radiation therapy. The photosensitizer (PS) excited at certain wavelengths of the applied light source, in the presence of oxygen releases several free radicals and various oxidation products with high cytotoxic potential, which will lead to cell death in irradiated cancerous tissues. Current research focuses on the potential of natural products as a superior generation of photosensitizers, which through the latest nanotechnologies target tumors better, are less toxic to neighboring tissues, but at the same time, have improved light absorption for the more aggressive and widespread forms of cancer. Curcumin incorporated into nanotechnologies has a higher intracellular absorption, a higher targeting rate, increased toxicity to tumor cells, accelerates the activity of caspases and DNA cleavage, decreases the mitochondrial activity of cancer cells, decreases their viability and proliferation, decreases angiogenesis, and finally induces apoptosis. It reduces the size of the primary tumor, reverses multidrug resistance in chemotherapy and decreases resistance to radiation therapy in neoplasms. Current research has shown that the use of PDT and nanoformulations of curcumin has a modulating effect on ROS generation, so light or laser irradiation will lead to excessive ROS growth, while nanocurcumin will reduce the activation of ROS-producing enzymes or will determine the quick removal of ROS, seemingly opposite but synergistic phenomena by inducing neoplasm apoptosis, but at the same time, accelerating the repair of nearby tissue. The latest curcumin nanoformulations have a huge potential to optimize PDT, to overcome major side effects, resistance to chemotherapy, relapses and metastases. All the studies reviewed and presented revealed great potential for the applicability of nanoformulations of curcumin and PDT in cancer therapy.

Graphene and its derivatives: understanding the main chemical and medicinal chemistry roles for biomedical applications

Over the past few years, there has been a growing potential use of graphene and its derivatives in several biomedical areas, such as drug delivery systems, biosensors, and imaging systems, especially for having excellent optical, electronic, thermal, and mechanical properties. Therefore, nanomaterials in the graphene family have shown promising results in several areas of science. The different physicochemical properties of graphene and its derivatives guide its biocompatibility and toxicity. Hence, further studies to explain the interactions of these nanomaterials with biological systems are fundamental. This review has shown the applicability of the graphene family in several biomedical modalities, with particular attention for cancer therapy and diagnosis, as a potent theranostic. This ability is derivative from the considerable number of forms that the graphene family can assume. The graphene-based materials biodistribution profile, clearance, toxicity, and cytotoxicity, interacting with biological systems, are discussed here, focusing on its synthesis methodology, physicochemical properties, and production quality. Despite the growing increase in the bioavailability and toxicity studies of graphene and its derivatives, there is still much to be unveiled to develop safe and effective formulations.

Graphic abstract

Magnetic and GRPR-targeted reduced graphene oxide/doxorubicin nanocomposite for dual-targeted chemo-photothermal cancer therapy

Herein, we design a rGO-based magnetic nanocomposite by decorating rGO with citrate-coated magnetic nanoparticles (CMNP). The magnetic rGO (mrGO) was modified by phospholipid-polyethylene glycol to prepare PEGylated mrGO, for conjugating with gastrin-releasing peptide receptor (GRPR)-binding peptide (mrGOG). The anticancer drug doxorubicin (DOX) was bound to mrGO (mrGOG) by π-π stacking for drug delivery triggered by the low pH value in the endosome. The mrGOG showed enhanced photothermal effect under NIR irradiation, endorsing its role for dual targeted DOX delivery. With efficient DOX release in the endosomal environment and heat generation from light absorption in the NIR range, mrGOG/DOX could be used for combination chemo-photothermal therapy after intracellular uptake by cancer cells. We characterized the physico-chemical as well as biological properties of the synthesized nanocomposites. The mrGOG is stable in biological buffer solution, showing high biocompatibility and minimum hemolytic properties. Using U87 glioblastoma cells, we confirmed the magnetic drug targeting effect in vitro for selective cancer cell killing. The peptide ligand-mediated targeted delivery increases the efficiency of intracellular uptake of both nanocomposite and DOX up to ~3 times due to the over-expressed GRPR on U87 surface, leading to higher cytotoxicity. The increased cytotoxicity using mrGOG over mrGO was shown from a decreased IC₅₀ value (0.70 to 0.48 μg/mL) and an increased cell apoptosis rate (19.8% to 47.1%). The IC₅₀ and apoptosis rate changed further to 0.19 μg/mL and 76.8% in combination with NIR laser irradiation, with the photothermal effect supported from upregulation of heat shock protein HSP70 expression. Using U87 tumor xenograft model created in nude mice, we demonstrated that magnetic guidance after intravenous delivery of mrGOG/DOX could significantly reduce tumor size and prolong animal survival over free DOX and non-magnetic guided groups. Augmented with NIR laser treatment for 5 min, the anti-cancer efficacy significantly improves with elevated cell apoptosis and reduced cell proliferation. Together with safety profiles from hematological as well as major organ histological analysis of treated animals, the mrGOG nanocomposite is an effective nanomaterial for combination chemo-photothermal cancer therapy.

Competition between the Photothermal Effect and Emission in Potential Phototherapy Agents

Planar donor-acceptor-donor (D-A-D) organic molecules have been highlighted as promising photothermal agents due to their good light-to-heat conversion ratio, easy degradation, and chemical tunability. Very recently, it has been demonstrated that their photothermal conversion can be boosted by appending rather long alkyl chains. Despite this behavior being tentatively associated with the population of a nonradiative twisted intramolecular charge transfer (TICT) state driven by an intramolecular motion, the precise mechanisms and the role played by the environment, and most notably aggregation, still remain elusive. In this context, we carried out a series of time-dependent density functional theory (TD-DFT) calculations combined with molecular dynamics (MD) simulations to achieve a realistic description of the isolated and aggregated systems. Our theoretical models unambiguously evidence that the population of CT states is very unlikely in both cases, whereas the light-triggered heat dissipation can be ascribed to the activation of specific vibrational degrees of freedom related to the relative motion of the peripheral chains. Overall, our results clearly corroborate the active role played by the alkyl substituents in the photothermal conversion through vibrational motion, while breaking from the conventional picture, which invokes the formation of dark TICT states in loosely packed aggregates.

Precision photothermal therapy and photoacoustic imaging by in situ activatable thermoplasmonics

Phototherapy holds great promise for disease treatment; however, traditional "always-on" photoagents have been restricted to clinical translation due to their nonspecific response and side effects on normal tissues. Here, we show a tumor microenvironment activated photothermal and photoacoustic agent as an activatable prodrug and probe that allows precise cancer diagnosis and treatment. Such an in situ revitalized therapeutic and contrast agent is achieved via controllable plasmonic heating for thermoplasmonic activation. This enables monitoring of signal molecule dynamics, real-time photothermal and photoacoustic imaging of tumors and lymph node metastasis, and targeted photothermal therapy without unwanted phototoxicity to normal tissues. Our study provides a practical solution to the non-specificity problem in phototherapy and offers precision cancer therapeutic and theranostic strategies. This work may advance the development of ultrasensitive disease diagnosis and precision medicine.

Near-Infrared Heptamethine Cyanine Dyes for Nanoparticle-Based Photoacoustic Imaging and Photothermal Therapy

We have synthesized and characterized a library of near-infrared (NIR) heptamethine cyanine dyes for biomedical application as photoacoustic imaging and photothermal agents. These hydrophobic dyes were incorporated into a polymer-based nanoparticle system to provide aqueous solubility and protection of the photophysical properties of each dye scaffold. Among those heptamethine cyanine dyes analyzed, 13 compounds within the nontoxic polymeric nanoparticles have been selected to exemplify structural relationships in terms of photostability, photoacoustic imaging, and photothermal behavior within the NIR (∼650-850 nm) spectral region. The most contributing structural features observed in our dye design include hydrophobicity, rotatable bonds, heavy atom effects, and stability of the central cyclohexene ring within the dye core. The NIR agents developed within this project serve to elicit a structure-function relationship with emphasis on their photoacoustic and photothermal characteristics aiming at producing customizable NIR photoacoustic and photothermal tools for clinical use.

[Mn2+-doped Prussian blue nanoparticles for T1-T2 dual-mode magnetic resonance imaging and photothermal therapy in vitro]

OBJECTIVE

To prepare Mn2+-doped Prussian blue nanoparticles (Mn-PB NPs) for T1-T2 dual-mode magnetic resonance imaging (MRI) and photothermal therapy in vitro.

OBJECTIVE

Mn-PB NPs were prepared based on manganese chloride, ferrous chloride and potassium ferricyanide using the microemulsion method. The performance of T1-T2 dual-mode MRI with Mn-PB NPs and the photothermal property of the nanoparticles were assessed. CCK-8 assay and AM/PI double staining were used to evaluate the effect of photothermal therapy in vitro using the parepared nanoparticles.

OBJECTIVE

The prepared Mn-PB NPs had a mean particle size of 39.46±0.42 nm with a Zeta potential of -25.9±1.2 mV and exhibited a good dispersibility and uniform particle size. In MRI using the nanoparticles, the r1 and r2 values reached 0.68 and 3.65 (mmol/L)-1s-1, respectively, indicating good performance of Mn-PB NPs for T1 and T2 enhancement in MRI. When irradiated with 808 nm laser for 10 min, Mn-PB NPs showed a temperature rise to 90 ℃ to cause significant reduction of cell survival. CCK-8 assay and AM/PI double staining confirmed that Mn-PB NPs were capable of efficient killing of HepG2 cells upon 808 nm laser irradiation.

OBJECTIVE

The Mn-PB NPs prepared in this work have uniform particle size and show good performances both in MRI for T1 and T2 enhancement and in photothermal therapy in vitro without obvious cytotoxicity.