Near-Infrared-Responsive Cancer Photothermal and Photodynamic Therapy Using Gold Nanoparticles

Harnessing the power of thermosensitive liposomes with gold nanoprisms and silica for controlled drug delivery in combined chemotherapy and phototherapy

In recent years, the scientific community has tried to address the treatment of complex diseases such as cancer in a more appropriate and promising way. Regarding this and benefiting from the unique optical properties of gold nanoprisms (AuNPRs), the physicochemical properties of thermosensitive liposomes (TSLs), and the tunable drug encapsulation and release properties of silica nanoparticles (BioSi@NPs), this study has developed two nanoformulations. These nanoformulations have the potential to integrate chemotherapy and photothermal therapy within a single entity. Once their components were synthesized and characterized separately, two strategies were taken in order to develop these multifunctional nanoformulations: (1) covalent binding of AuNPRs to TSLs and (2) co-encapsulation of both components within BioSi@NPs, without modifying the optical and physicochemical properties of AuNPRs and TSLs. Finally, the suitability of both nanoformulations to carry and release hydrophilic drugs when triggered by a 1064 nm NIR laser has been explored by using the fluorescent probe 5(6)-carboxyfluorescein (CF) as a hydrophilic drug model. Different laser power and time of exposure were also tested evidencing that hydrophilic drugs were only released from TSLs in the presence of AuNPRs and that the drug release profile was dependent on the type of nanoformulation and irradiation conditions used. In conclusion, these multifunctional nanoformulations exhibit promising potential for controlled drug delivery in combined chemotherapy and phototherapy, with the capability to precisely control the release kinetics based on specific therapeutic needs.

Recent Advances in Photodynamic Therapy: Metal-Based Nanoparticles as Tools to Improve Cancer Therapy

Cancer remains a significant global health challenge, with traditional therapies like surgery, chemotherapy, and radiation often accompanied by systemic toxicity and damage to healthy tissues. Despite progress in treatment, these approaches have limitations such as non-specific targeting, systemic toxicity, and resistance development in cancer cells. In recent years, nanotechnology has emerged as a revolutionary frontier in cancer therapy, offering potential solutions to these challenges. Nanoparticles, due to their unique physical and chemical properties, can carry therapeutic payloads, navigate biological barriers, and selectively target cancer cells. Metal-based nanoparticles, in particular, offer unique properties suitable for various therapeutic applications. Recent advancements have focused on the integration of metal-based nanoparticles to enhance the efficacy and precision of photodynamic therapy. Integrating nanotechnology into cancer therapy represents a paradigm shift, enabling the development of strategies with enhanced specificity and reduced off-target effects. This review aims to provide a comprehensive understanding of the pivotal role of metal-based nanoparticles in photodynamic therapy. We explore the mechanisms, biocompatibility, and applications of metal-based nanoparticles in photodynamic therapy, highlighting the challenges and the limitations in their use, as well as the combining of metal-based nanoparticles/photodynamic therapy with other strategies as a synergistic therapeutic approach for cancer treatment.

Biogenic fabrication of a gold nanoparticle sensor for detection of Fe3+ ions using a smartphone and machine learning

In recent years, smartphones have been integrated into rapid colorimetric sensors for heavy metal ions, but challenges persist in accuracy and efficiency. Our study introduces a novel approach to utilize biogenic gold nanoparticle (AuNP) sensors in conjunction with designing a lightbox with a color reference and machine learning for detection of Fe3+ ions in water. AuNPs were synthesized using the aqueous extract of Eleutherine bulbosa leaf as reductants and stabilizing agents. Physicochemical analyses revealed diverse AuNP shapes and sizes with an average size of 19.8 nm, with a crystalline structure confirmed via SAED and XRD techniques. AuNPs exhibited high sensitivity and selectivity in detection of Fe3+ ions through UV-vis spectroscopy and smartphones, relying on nanoparticle aggregation. To enhance image quality, we developed a lightbox and implemented a reference color value for standardization, significantly improving performance of machine learning algorithms. Our method achieved approximately 6.7% higher evaluation metrics (R 2 = 0.8780) compared to non-normalized approaches (R 2 = 0.8207). This work presented a promising tool for quantitative Fe3+ ion analysis in water.

Ultrafast light-activated polymeric nanomotors

Synthetic micro/nanomotors have been extensively exploited over the past decade to achieve active transportation. This interest is a result of their broad range of potential applications, from environmental remediation to nanomedicine. Nevertheless, it still remains a challenge to build a fast-moving biodegradable polymeric nanomotor. Here we present a light-propelled nanomotor by introducing gold nanoparticles (Au NP) onto biodegradable bowl-shaped polymersomes (stomatocytes) via electrostatic and hydrogen bond interactions. These biodegradable nanomotors show controllable motion and remarkable velocities of up to 125 μm s-1. This unique behavior is explained via a thorough three-dimensional characterization of the nanomotor, particularly the size and the spatial distribution of Au NP, with cryogenic transmission electron microscopy (cryo-TEM) and cryo-electron tomography (cryo-ET). Our in-depth quantitative 3D analysis reveals that the motile features of these nanomotors are caused by the nonuniform distribution of Au NPs on the outer surface of the stomatocyte along the z-axial direction. Their excellent motile features are exploited for active cargo delivery into living cells. This study provides a new approach to develop robust, biodegradable soft nanomotors with application potential in biomedicine.

Smart responsive in situ hydrogel systems applied in bone tissue engineering

The repair of irregular bone tissue suffers severe clinical problems due to the scarcity of an appropriate therapeutic carrier that can match dynamic and complex bone damage. Fortunately, stimuli-responsive in situ hydrogel systems that are triggered by a special microenvironment could be an ideal method of regenerating bone tissue because of the injectability, in situ gelatin, and spatiotemporally tunable drug release. Herein, we introduce the two main stimulus-response approaches, exogenous and endogenous, to forming in situ hydrogels in bone tissue engineering. First, we summarize specific and distinct responses to an extensive range of external stimuli (e.g., ultraviolet, near-infrared, ultrasound, etc.) to form in situ hydrogels created from biocompatible materials modified by various functional groups or hybrid functional nanoparticles. Furthermore, "smart" hydrogels, which respond to endogenous physiological or environmental stimuli (e.g., temperature, pH, enzyme, etc.), can achieve in situ gelation by one injection in vivo without additional intervention. Moreover, the mild chemistry response-mediated in situ hydrogel systems also offer fascinating prospects in bone tissue engineering, such as a Diels-Alder, Michael addition, thiol-Michael addition, and Schiff reactions, etc. The recent developments and challenges of various smart in situ hydrogels and their application to drug administration and bone tissue engineering are discussed in this review. It is anticipated that advanced strategies and innovative ideas of in situ hydrogels will be exploited in the clinical field and increase the quality of life for patients with bone damage.

Gold Nanorod-Loaded Nano-Contrast Agent with Composite Shell-Core Structure for Ultrasonic/Photothermal Imaging-Guided Therapy in Ischemic Muscle Disorders

Purpose

This study aims to broaden the application of nano-contrast agents (NCAs) within the realm of the musculoskeletal system. It aims to introduce novel methods, strategies, and insights for the clinical management of ischemic muscle disorders, encompassing diagnosis, monitoring, evaluation, and therapeutic intervention.

Methods

We developed a composite encapsulation technique employing O-carboxymethyl chitosan (OCMC) and liposome to encapsulate NCA-containing gold nanorods (GNRs) and perfluoropentane (PFP). This nanoscale contrast agent was thoroughly characterized for its basic physicochemical properties and performance. Its capabilities for in vivo and in vitro ultrasound imaging and photothermal imaging were authenticated, alongside a comprehensive biocompatibility assessment to ascertain its effects on microcirculatory perfusion in skeletal muscle using a murine model of hindlimb ischemia, and its potential to augment blood flow and facilitate recovery.

Results

The engineered GNR@OCMC-liposome/PFP nanostructure exhibited an average size of 203.18±1.49 nm, characterized by size uniformity, regular morphology, and a good biocompatibility profile. In vitro assessments revealed NCA's potent photothermal response and its transformation into microbubbles (MBs) under near-infrared (NIR) irradiation, thereby enhancing ultrasonographic visibility. Animal studies demonstrated the nanostructure's efficacy in photothermal imaging at ischemic loci in mouse hindlimbs, where NIR irradiation induced rapid temperature increases and significantly increased blood circulation.

Conclusion

The dual-modal ultrasound/photothermal NCA, encapsulating GNR and PFP within a composite shell-core architecture, was synthesized successfully. It demonstrated exceptional stability, biocompatibility, and phase transition efficiency. Importantly, it facilitates the encapsulation of PFP, enabling both enhanced ultrasound imaging and photothermal imaging following NIR light exposure. This advancement provides a critical step towards the integrated diagnosis and treatment of ischemic muscle diseases, signifying a pivotal development in nanomedicine for musculoskeletal therapeutics.

Near-infrared responsive gold nanorods for highly sensitive colorimetric and photothermal lateral flow immuno-detection of SARS-CoV-2

The highly infectious characteristics of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), highlight the necessity of sensitive and rapid nucleocapsid (N) protein-based antigen testing for early triage and epidemic management. In this study, a colorimetric and photothermal dual-mode lateral flow immunoassay (LFIA) platform for the rapid and sensitive detection of the SARS-CoV-2 N protein was developed based on gold nanorods (GNRs), which possessed tunable local surface plasma resonance (LSPR) absorption peaks from UV-visible to near-infrared (NIR). The LSPR peak was adjusted to match the NIR emission laser 808 nm by controlling the length-to-diameter ratio, which could maximize the photothermal conversion efficiency and achieve photothermal detection signal amplification. Qualitative detection of SARS-CoV-2 N protein was achieved by observing the strip color, and the limit of detection was 2 ng mL-1, while that for photothermal detection was 0.096 ng mL-1. Artificial saliva samples spiked with the N protein were analyzed with the recoveries ranging from 84.38% to 107.72%. The intra-assay and inter-assay coefficients of variation were 6.76% and 10.39%, respectively. We further evaluated the reliability of this platform by detecting 40 clinical samples collected from nasal swabs, and the results matched well with that of nucleic acid detection (87.5%). This method shows great promise in early disease diagnosis and screening.

Antibacterial Properties of an Experimental Dental Resin Loaded with Gold Nanoshells for Photothermal Therapy Applications

This study explored the chemical and antibacterial properties of a dental resin loaded with gold nanoshells (AuNPs) in conjunction with photothermal therapy (PTT) as a novel method against Streptococcus mutans (S. mutans) to prevent secondary caries. First, a 20-h minimum inhibitory concentration (MIC) assay was performed on solutions of AuNPs with planktonic S. mutans under an LED device and laser at 660 nm. Next, resin blends containing 0, 1 × 1010, or 2 × 1010 AuNPs/mL were fabricated, and the degree of conversion (DC) was measured using an FTIR spectroscopy. Lastly, a colony forming unit (CFU) count was performed following 24 h growth of S. mutans on 6 mm diameter resin disks with different light treatments of an LED device and a laser at 660 nm. The MIC results only showed a reduction in S. mutans at AuNP concentrations less than 3.12 µg/mL under a laser illumination level of 95.5 J/cm2 compared to the dark treatment (p < 0.010 for each). CFU and DC results showed no significant dependence on any light treatment studied. The AuNPs expressed antibacterial effects following PPT against planktonic S. mutans but not in a polymerized dental adhesive resin. Future studies should focus on different shapes, structure, and concentrations of AuNPs loaded in a resin blend.

Quantifying particle concentration via AI-enhanced optical coherence tomography

Efficient and robust quantification of the number of nanoparticles in solution is not only essential but also insufficient in nanotechnology and biomedical research. This paper proposes to use optical coherence tomography (OCT) to quantify the number of gold nanorods, which exemplify the nanoparticles with high light scattering signals. Additionally, we have developed an AI-enhanced OCT image processing to improve the accuracy and robustness of the quantification result.

Recent Advancements and Unexplored Biomedical Applications of Green Synthesized Ag and Au Nanoparticles: A Review

Green synthesis of silver (Ag) and gold (Au) nanoparticles (NPs) has acquired huge popularity owing to their potential applications in various fields. A large number of research articles exist in the literature describing the green synthesis of Ag and Au NPs for biomedical applications. However, these findings are scattered, making it time-consuming for researchers to locate promising advancements in Ag and Au NPs synthesis and their unexplored biomedical applications. Unlike other review articles, this systematic study not only highlights recent advancements in the green synthesis of Ag and Au NPs but also explores their potential unexplored biomedical applications. The article discusses the various synthesis approaches for the green synthesis of Ag and Au NPs highlighting the emerging developments and novel strategies. Then, the article reviews the important biomedical applications of green synthesized Ag and Au NPs by critically evaluating the expected advantages. To expose future research direction in the field, the article describes the unexplored biomedical applications of the NPs. Finally, the articles discuss the challenges and limitations in the green synthesis of Ag and Au NPs and their biomedical applications. This article will serve as a valuable reference for researchers, working on green synthesis of Ag and Au NPs for biomedical applications.

A simulation study on the radiosensitization properties of gold nanorods

Objective. Gold nanorods (GNRs) have emerged as versatile nanoparticles with unique properties, holding promise in various modalities of cancer treatment through drug delivery and photothermal therapy. In the rapidly evolving field of nanoparticle radiosensitization (NPRS) for cancer therapy, this study assessed the potential of gold nanorods as radiosensitizing agents by quantifying the key features of NPRS, such as secondary electron emission and dose enhancement, using Monte Carlo simulations.Approach. Employing the TOPAS track structure code, we conducted a comprehensive evaluation of the radiosensitization behavior of spherical gold nanoparticles and gold nanorods. We systematically explored the impact of nanorod geometry (in particular size and aspect ratio) and orientation on secondary electron emission and deposited energy ratio, providing validated results against previously published simulations.Main results. Our findings demonstrate that gold nanorods exhibit comparable secondary electron emission to their spherical counterparts. Notably, nanorods with smaller surface-area-to-volume ratios (SA:V) and alignment with the incident photon beam proved to be more efficient radiosensitizing agents, showing superiority in emitted electron fluence. However, in the microscale, the deposited energy ratio (DER) was not markedly influenced by the SA:V of the nanorod. Additionally, our findings revealed that the geometry of gold nanoparticles has a more significant impact on the emission of M-shell Auger electrons (with energies below 3.5 keV) than on higher-energy electrons.Significance. This research investigated the radiosensitization properties of gold nanorods, positioning them as promising alternatives to the more conventionally studied spherical gold nanoparticles in the context of cancer research. With increasing interest in multimodal cancer therapy, our findings have the potential to contribute valuable insights into the perspective of gold nanorods as effective multipurpose agents for synergistic photothermal therapy and radiotherapy. Future directions may involve exploring alternative metallic nanorods as well as further optimizing the geometry and coating materials, opening new possibilities for more effective cancer treatments.

Recent nanotheranostic approaches in cancer research

Humanity is suffering from cancer which has become a root cause of untimely deaths of individuals around the globe in the recent past. Nanotheranostics integrates therapeutics and diagnostics to monitor treatment response and enhance drug efficacy and safety. We hereby propose to discuss all recent cancer imaging and diagnostic tools, the mechanism of targeting tumor cells, and current nanotheranostic platforms available for cancer. This review discusses various nanotheranostic agents and novel molecular imaging tools like MRI, CT, PET, SPEC, and PAT used for cancer diagnostics. Emphasis is given to gold nanoparticles, silica, liposomes, dendrimers, and metal-based agents. We also highlight the mechanism of targeting the tumor cells, and the limitations of different nanotheranostic agents in the field of research for cancer treatment. Due to the complexity in this area, multifunctional and hybrid nanoparticles functionalized with targeted moieties or anti-cancer drugs show the best feature for theranostics that enables them to work on carrying and delivering active materials to the desired area of the requirement for early detection and diagnosis. Non-invasive imaging techniques have a specificity of receptor binding and internalization processes of the nanosystems within the cancer cells. Nanotheranostics may provide the appropriate medicine at the appropriate dose to the appropriate patient at the appropriate time.

Research Progress of Polysaccharide-Gold Nanocomplexes in Drug Delivery

Clinical drug administration aims to deliver drugs efficiently and safely to target tissues, organs, and cells, with the objective of enabling their therapeutic effects. Currently, the main approach to enhance a drug's effectiveness is ensuring its efficient delivery to the intended site. Due to the fact that there are still various drawbacks of traditional drug delivery methods, such as high toxicity and side effects, insufficient drug specificity, poor targeting, and poor pharmacokinetic performance, nanocarriers have emerged as a promising alternative. Nanocarriers possess significant advantages in drug delivery due to their size tunability and surface modifiability. Moreover, nano-drug delivery systems have demonstrated strong potential in terms of prolonging drug circulation time, improving bioavailability, increasing drug retention at the tumor site, decreasing drug resistance, as well as reducing the undesirable side effects of anticancer drugs. Numerous studies have focused on utilizing polysaccharides as nanodelivery carriers, developing delivery systems based on polysaccharides, or exploiting polysaccharides as tumor-targeting ligands to enhance the precision of nanoparticle delivery. These types of investigations have become commonplace in the academic literature. This review aims to elucidate the preparation methods and principles of polysaccharide gold nanocarriers. It also provides an overview of the factors that affect the loading of polysaccharide gold nanocarriers with different kinds of drugs. Additionally, it outlines the strategies employed by polysaccharide gold nanocarriers to improve the delivery efficiency of various drugs. The objective is to provide a reference for further development of research on polysaccharide gold nanodelivery systems.

Light-Driven Biomimetic Nanomotors for Enhanced Photothermal Therapy

Nanotechnology-based strategy has recently drawn extensive attention for the therapy of malignant tumors due to its distinct strengths in cancer diagnosis and treatment. However, the limited intratumoral permeability of nanoparticles is a major hurdle to achieving the desired effect of cancer treatment. Due to their superior cargo towing and reliable penetrating property, micro-/nanomotors (MNMs) are considered as one of the most potential candidates for the coming generation of drug delivery platforms. Here, near-infrared (NIR)-actuated biomimetic nanomotors (4T1-JPGSs-IND) are fabricated successfully and we demonstrate that 4T1-JPGSs-IND selectively accumulate in homologous tumor regions due to the effective homing ability. Upon laser irradiation, hyperthermia generated by 4T1-JPGSs-IND leads to self-thermophoretic motion and photothermal therapy (PTT) to ablate tumors with a deep depth, thereby improving the photothermal therapeutic effect for cancer management. The developed nanomotor system with multifunctionalities exhibits promising potential in biomedical applications to fight against various diseases.

Advent in proteins, nucleic acids, and biological cell membranes functionalized nanocarriers to accomplish active or homologous tumor targeting for smart amalgamated chemotherapy/photo-therapy: A review

Conventional cancer mono-therapeutic approaches including radiotherapy, surgery, and chemotherapy don't always achieve satisfactory outcomes and are frequently associated with significant limitations. Although chemotherapy is a vital intervention, its effectiveness is frequently inadequate and is associated with metastasis, multidrug resistance, off-target effect, and normal cells toxicity. Phototherapies are employed in cancer therapy, encompassing photo-dynamic and photo-thermal therapies which under favorable NIR laser light irradiation initiate the included photosensitizers and photo-thermal agents to generate ROS or thermal heat respectively for cancer cells destruction. Photo-therapy is considered noninvasive, posing no resistance, but it still suffers from several pitfalls like low penetration depth and excessive heat generation affecting neighboring tissues. Improved selectivity and tumor-homing capacity could be attained through surface modulation of nanoparticles with targeting ligands that bind to receptors, which are exclusively overexpressed on cancerous cells. Developing novel modified targeted nanoparticulate platforms integrating different therapeutic modalities like photo-therapy and chemotherapy is a topic of active research. This review aimed to highlight recent advances in proteins, nucleic acids, and biological cell membranes functionalized nanocarriers for smart combinatorial chemotherapy/photo-therapy. Nanocarriers decorated with precise targeting ligands, like aptamers, antibody, and lactoferrin, to achieve active tumor-targeting or camouflaging using various biological cell membrane coating are designed to achieve homologous tumor-targeting.

Plasmonic porous micro- and nano-materials based on Au/Ag nanostructures developed for photothermal cancer therapy: challenges in clinicalization

Photothermal therapy (PTT) has developed in recent decades as a relatively safe method for the treatment of cancers. Recently, various species of gold and silver (Au and Ag) nanostructures have been developed and investigated to achieve PTT due to their highly localized surface plasmon resonance (LSPR) effect. Concisely, the collective oscillation of electrons on the surface of Au and Ag nanostructures upon exposure to a specific wavelength (depending on their size and shape) and further plasmonic resonance leads to the heating of the surface of these particles. Hence, porous species can be equipped with tiny plasmonic ingredients that add plasmonic properties to therapeutic cargoes. In this case, a precise review of the recent achievements is very important to figure out to what extent plasmonic photothermal therapy (PPTT) by Au/Ag-based plasmonic porous nanomedicines successfully treated cancers with satisfactory biosafety. Herein, we classify the various species of LSPR-active micro- and nano-materials. Moreover, the routes for the preparation of Ag/Au-plasmonic porous cargoes and related bench assessments are carefully reviewed. Finally, as the main aim of this study, principal requirements for the clinicalization of Ag/Au-plasmonic porous cargoes and their further challenges are discussed, which are critical for specialists in this field.

Carboxylated graphene quantum dots-mediated photothermal therapy enhances drug-membrane permeability, ROS production, and the immune system recruitment on 3D glioblastoma models

Graphene quantum dots (GQDs) are biocompatible nanoparticles employed in biomedical field, thanks to their size and photophysical properties. GQDs have shown the capability to cross biological barriers, including the blood–brain barrier, which makes them promising agents for brain diseases therapy. It has been shown that surface-functionalized GQDs enhance membrane fluidity and intracellular uptake, exerting a synergistic effect with antitumor drugs at subtherapeutic doses. Here, we tested GQDs effects in combination with chemotherapeutic agents doxorubicin and temozolomide, on a complex 3D spheroid model of glioblastoma. We observed that the capability of GQDs to absorb and convert near-infrared light into heat is a key factor in membrane permeability enhancement on 3D model. This non-invasive therapeutic strategy named photothermal therapy (PTT), combined to chemotherapy at subtherapeutic doses, significantly increased the effect of antitumor drugs by reducing tumor growth and viability. Furthermore, the increase in membrane permeability due to GQDs-mediated PTT enhanced the release of reactive oxygen species with strong migration of the immune system towards irradiated cancer spheroids. Our data indicate that the increase in membrane permeability can enhance the efficacy of antitumor drugs at subtherapeutic doses against glioblastoma, reducing side effects, and directing immune response, ultimately improving quality of life for patients.

Bacterial outer membrane vesicles as drug delivery carrier for photodynamic anticancer therapy

Photodynamic Therapy (PDT) is an effective tumor treatment strategy that not only induces photocytotoxicity to kill tumor cells directly but also activates the immune system in the body to generate tumor-specific immunity, preventing cancer metastasis and recurrence. However, some limitations of PDT limit the therapeutic efficacy in deep tumors. Previous studies have used different types of nanoparticles (NPs) as drug carriers of photosensitizers (PSs) to overcome the shortcomings of PDT and improve therapeutic efficacy. Among them, bacterial outer membrane vesicles (OMVs) have natural advantages as carriers for PS delivery. In addition to the targeted delivery of PSs into tumor cells, their unique immunogenicity helps them to serve as immune adjuvants to enhance the PDT-induced immune effect, providing new ideas for photodynamic anticancer therapy. Therefore, in this review, we will introduce the biogenesis and anticancer functions of OMVs and the research on them as drug delivery carriers in PDT. Finally, we also discuss the challenges and prospects of OMVs as a versatile drug delivery carrier for photodynamic anticancer therapy.

Photothermal Effect of Gold Nanoparticles as a Nanomedicine for Diagnosis and Therapeutics

Gold nanoparticles (AuNPs) have received great attention for various medical applications due to their unique physicochemical properties. AuNPs with tunable optical properties in the visible and near-infrared regions have been utilized in a variety of applications such as in vitro diagnostics, in vivo imaging, and therapeutics. Among the applications, this review will pay more attention to recent developments in diagnostic and therapeutic applications based on the photothermal (PT) effect of AuNPs. In particular, the PT effect of AuNPs has played an important role in medical applications utilizing light, such as photoacoustic imaging, photon polymerase chain reaction (PCR), and hyperthermia therapy. First, we discuss the fundamentals of the optical properties in detail to understand the background of the PT effect of AuNPs. For diagnostic applications, the ability of AuNPs to efficiently convert absorbed light energy into heat to generate enhanced acoustic waves can lead to significant enhancements in photoacoustic signal intensity. Integration of the PT effect of AuNPs with PCR may open new opportunities for technological innovation called photonic PCR, where light is used to enable fast and accurate temperature cycling for DNA amplification. Additionally, beyond the existing thermotherapy of AuNPs, the PT effect of AuNPs can be further applied to cancer immunotherapy. Controlled PT damage to cancer cells triggers an immune response, which is useful for obtaining better outcomes in combination with immune checkpoint inhibitors or vaccines. Therefore, this review examines applications to nanomedicine based on the PT effect among the unique optical properties of AuNPs, understands the basic principles, the advantages and disadvantages of each technology, and understands the importance of a multidisciplinary approach. Based on this, it is expected that it will help understand the current status and development direction of new nanoparticle-based disease diagnosis methods and treatment methods, and we hope that it will inspire the development of new innovative technologies.

Immunotherapeutic effect of photothermal-mediated exosomes secreted from breast cancer cells

Aim: Exosomal damage-associated molecular patterns can play a key role in immunostimulation and changing the cold tumor microenvironment to hot. Materials & methods: This study examined the immunostimulation effect of photothermal and hyperthermia-treated 4T1 cell-derived exosomes on 4T1 cell-induced breast tumors in BALB/c animal models. Exosomes were characterized for HSP70, HSP90 and HMGB-1 before injection into mice and tumor tissues were analyzed for IL-6, IL-12 and IL-1β, CD4 and CD8 T-cell permeability, and PD-L1 expression. Results: Thermal treatments increased high damage-associated molecular patterns containing exosome secretion and the permeability of T cells to tumors, leading to tumor growth inhibition. Conclusion: Photothermal-derived exosomes showed higher damage-associated molecular patterns than hyperthermia with a higher immunostimulation and inhibiting tumor growth effect.

Highly Sensitive Photothermal Microfluidic Thread-Based Duplex Immunosensor for Point-of-Care Monitoring

Herein, we successfully developed a thread-based analytical device (μTAD) for simultaneous immunosensing of two biomolecules with attomolar sensitivity by using a photothermal effect. A photothermal effect exploits a strong light-to-heat energy conversion of plasmonic metallic nanoparticles at localized surface plasmon resonance. The key innovation is to utilize the cotton thread to realize this sensor and the use of chitosan modification for enhancing the microfluidic properties, for improving the efficiency of photothermal conversion, and for sensor stability. The developed μTAD sensor consists of (i) a sample zone, (ii) a conjugation zone coated with gold nanoparticles bound with an antibody (AuNPs-Ab2), and (iii) a test zone immobilized with a capture antibody (anti-Ab1). The prepared μTAD is assembled in a custom three-dimensional (3D) printed device which holds the laser for illumination and the thermometer for readout. The 3D-printed supportive device enhances signal response by focusing light and localizing the heat generated. For proof of concept, simultaneous sensing of two key stress and inflammation biomarkers, namely, cortisol and interleukin-6 (IL-6), are monitored using this technique. Under optimization, this device exhibited a detection linear range of 2.0-14.0 ag/mL (R2 = 0.9988) and 30.0-360.0 fg/mL (R2 = 0.9942) with a detection limit (LOD) of 1.40 ag/mL (∼3.86 amol/L) and 20.0 fg/mL (∼950.0 amol/L) for cortisol and IL-6, respectively. Furthermore, the analysis of both biomolecules in human samples indicated recoveries in the range of 98.8%-102.88% with the highest relative standard deviation being 3.49%, offering great accuracy and precision. These results are the highest reported sensitivity for these analytes using an immunoassay method. Our PT-μTAD strategy is therefore a promising approach for detecting biomolecules in resource-limited point-of-care settings.

Surface Functionalization of Gold Nanoparticles for Targeting the Tumor Microenvironment to Improve Antitumor Efficiency

Gold nanoparticles (AuNPs) have undergone significant research for their use in the treatment of cancer. Numerous researchers have established their potent antitumor properties, which have greatly impacted the treatment of cancer. AuNPs have been used in four primary anticancer treatment modalities, namely radiation, photothermal therapy, photodynamic therapy, and chemotherapy. However, the ability of AuNPs to destroy cancer is lacking and can even harm healthy cells without the right direction to transport them to the tumor microenvironment. Consequently, a suitable targeting technique is needed. Based on the distinct features of the human tumor microenvironment, this review discusses four different targeting strategies that target the four key features of the tumor microenvironment, including abnormal vasculature, overexpression of specific receptors, an acidic microenvironment, and a hypoxic microenvironment, to direct surface-functionalized AuNPs to the tumor microenvironment and increase antitumor efficacies. In addition, some current completed or ongoing clinical trials of AuNPs will also be discussed below to further reinforce the concept of using AuNPs in anticancer therapy.

Combinations of Photodynamic Therapy with Other Minimally Invasive Therapeutic Technologies against Cancer and Microbial Infections

The rapid rise in research and development following the discovery of photodynamic therapy to establish novel photosensitizers and overcome the limitations of the technology soon after its clinical translation has given rise to a few significant milestones. These include several novel generations of photosensitizers, the widening of the scope of applications, leveraging of the offerings of nanotechnology for greater efficacy, selectivity for the disease over host tissue and cells, the advent of combination therapies with other similarly minimally invasive therapeutic technologies, the use of stimulus-responsive delivery and disease targeting, and greater penetration depth of the activation energy. Brought together, all these milestones have contributed to the significant enhancement of what is still arguably a novel technology. Yet the major applications of photodynamic therapy still remain firmly located in neoplasms, from where most of the new innovations appear to launch to other areas, such as microbial, fungal, viral, acne, wet age-related macular degeneration, atherosclerosis, psoriasis, environmental sanitization, pest control, and dermatology. Three main value propositions of combinations of photodynamic therapy include the synergistic and additive enhancement of efficacy, the relatively low emergence of resistance and its rapid development as a targeted and high-precision therapy. Combinations with established methods such as chemotherapy and radiotherapy and demonstrated applications in mop-up surgery promise to enhance these top three clinical tools. From published in vitro and preclinical studies, clinical trials and applications, and postclinical case studies, seven combinations with photodynamic therapy have become prominent research interests because they are potentially easily applied, showing enhanced efficacy, and are rapidly translating to the clinic. These include combinations with chemotherapy, photothermal therapy, magnetic hyperthermia, cold plasma therapy, sonodynamic therapy, immunotherapy, and radiotherapy. Photochemical internalization is a critical mechanism for some combinations.

Gold nanoparticles and gold nanorods in the landscape of cancer therapy

Cancer is a grievous disease whose treatment requires a more efficient, non-invasive therapy, associated with minimal side effects. Gold nanoparticles possessing greatly impressive optical properties have been a forerunner in bioengineered cancer therapy. This theranostic system has gained immense popularity and finds its application in the field of molecular detection, biological imaging, cancer cell targeting, etc. The photothermal property of nanoparticles, especially of gold nanorods, causes absorption of the light incident by the light source, and transforms it into heat, resulting in tumor cell destruction. This review describes the different optical features of gold nanoparticles and summarizes the advance research done for the application of gold nanoparticles and precisely gold nanorods for combating various cancers including breast, lung, colon, oral, prostate, and pancreatic cancer.

Enhanced Nanobubble Formation: Gold Nanoparticle Conjugation to Qβ Virus-like Particles

Plasmonic gold nanostructures are a prevalent tool in modern hypersensitive analytical techniques such as photoablation, bioimaging, and biosensing. Recent studies have shown that gold nanostructures generate transient nanobubbles through localized heating and have been found in various biomedical applications. However, the current method of plasmonic nanoparticle cavitation events has several disadvantages, specifically including small metal nanostructures (≤10 nm) which lack size control, tuneability, and tissue localization by use of ultrashort pulses (ns, ps) and high-energy lasers which can result in tissue and cellular damage. This research investigates a method to immobilize sub-10 nm AuNPs (3.5 and 5 nm) onto a chemically modified thiol-rich surface of Qβ virus-like particles. These findings demonstrate that the multivalent display of sub-10 nm gold nanoparticles (AuNPs) caused a profound and disproportionate increase in photocavitation by upward of 5-7-fold and significantly lowered the laser fluency by 4-fold when compared to individual sub-10 nm AuNPs. Furthermore, computational modeling showed that the cooling time of QβAuNP scaffolds is significantly extended than that of individual AuNPs, proving greater control of laser fluency and nanobubble generation as seen in the experimental data. Ultimately, these findings showed how QβAuNP composites are more effective at nanobubble generation than current methods of plasmonic nanoparticle cavitation.

Folic acid-maltodextrin polymer coated magnetic graphene oxide as a NIR-responsive nano-drug delivery system for chemo-photothermal synergistic inhibition of tumor cells

The combination of chemo-photothermal therapy with high efficiency and fewer side effects has a good application prospect in cancer treatment. It is of great significance to construct a nano-drug delivery system with cancer cell targeting, high drug loading and excellent photothermal conversion efficiency. Therefore, a novel nano-drug carrier MGO-MDP-FA was successfully constructed by coating folic acid-grafted maltodextrin polymers (MDP-FA) on the surface of Fe₃O₄-modified graphene oxide (MGO). The nano-drug carrier combined the cancer cell targeting of FA and the magnetic targeting of MGO. A large amount of anti-cancer drug doxorubicin (DOX) was loaded by π-π interaction, hydrogen bond interaction and hydrophobic interaction, with the maximum loading amount and loading capacity of 657.9 mg g^-1 and 39.68 wt%, respectively. Based on the excellent photothermal conversion efficiency of MGO, MGO-MDP-FA showed good thermal ablation effect of tumor cells in vitro under NIR irradiation. In addition, MGO-MDP-FA@DOX showed excellent chemo-photothermal synergistic tumor inhibition in vitro (tumor cell killing rate reached 80%). In conclusion, the novel nano-drug delivery system MGO-MDP-FA constructed in this paper provides a promising nano-platform for chemo-photothermal synergistic treatment of cancer.

Plasmonic nanotechnology for photothermal applications - an evaluation

The application of plasmonic nanoparticles is motivated by the phenomenon of surface plasmon resonance. Owing to the tunability of optothermal properties and enhanced stability, these nanostructures show a wide range of applications in optical sensors, steam generation, water desalination, thermal energy storage, and biomedical applications such as photothermal (PT) therapy. The PT effect, that is, the conversion of absorbed light to heat by these particles, has led to thriving research regarding the utilization of plasmonic nanoparticles for a myriad of applications. The design of conventional nanomaterials for PT conversion has focussed predominantly on the manipulation of photon absorption through bandgap engineering, doping, incorporation, and modification of suitable matrix materials. Plasmonic nanomaterials offer an alternative and attractive approach in this regard, through the flexibility in the excitation of surface plasmons. Specific advantages are the considerable improved bandwidth of the absorption, a higher efficiency of photon absorption, facile tuning, as well as flexibility in the synthesis of plasmonic nanomaterials. This review of plasmonic PT (PPT) research begins with a theoretical discussion on the plasmonic properties of nanoparticles by means of the quasi-static approximation, Mie theory, Gans theory, generic simulations on common plasmonic material morphologies, and the evaluation processes of PT performance. Further, a variety of nanomaterials and material classes that have potential for PPT conversion are elucidated, such as plasmonic metals, bimetals, and metal-metal oxide nanocomposites. A detailed investigation of the essential, but often ignored, concept of thermal, chemical, and aggregation stability of nanoparticles is another part of this review. The challenges that remain, as well as prospective directions and chemistries, regarding nanomaterials for PT conversion are pondered on in the final section of the article, taking into account the specific requirements from different applications.

Inorganic Nanomaterials Used in Anti-Cancer Therapies:Further Developments

In this article, we provide an overview of the progress of scientists working to improve the quality of life of cancer patients. Among the known methods, cancer treatment methods focusing on the synergistic action of nanoparticles and nanocomposites have been proposed and described. The application of composite systems will allow precise delivery of therapeutic agents to cancer cells without systemic toxicity. The nanosystems described could be used as a high-efficiency photothermal therapy system by exploiting the properties of the individual nanoparticle components, including their magnetic, photothermal, complex, and bioactive properties. By combining the advantages of the individual components, it is possible to obtain a product that would be effective in cancer treatment. The use of nanomaterials to produce both drug carriers and those active substances with a direct anti-cancer effect has been extensively discussed. In this section, attention is paid to metallic nanoparticles, metal oxides, magnetic nanoparticles, and others. The use of complex compounds in biomedicine is also described. A group of compounds showing significant potential in anti-cancer therapies are natural compounds, which have also been discussed.

Gold nanorods assisted photothermal therapy of bladder cancer in mice: A computational study on the effects of gold nanorods distribution at the centre, periphery, and surface of bladder cancer

BACKGROUND AND OBJECTIVES

Gold nanorod-assisted photothermal therapy (GNR-PTT) is a cancer treatment whereby GNRs incorporated into the tumour act as photo-absorbers to elevate the thermal destruction effect. In the case of bladder, there are few possible routes to target the tumour with GNRs, namely peri/intra-tumoural injection and intravesical instillation of GNRs. These two approaches lead to different GNR distribution inside the tumour and can affect the treatment outcome.

METHODOLOGY

The present study investigates the effects of heterogeneous GNR distribution in a typical setup of GNR-PTT. Three cases were considered. Case 1 considered the GNRs at the tumour centre, while Case 2 represents a hypothetical scenario where GNRs are distributed at the tumour periphery; these two cases represent intratumoural accumulation with different degree of GNR spread inside the tumour. Case 3 is achieved when GNRs target the exposed tumoural surface that is invading the bladder wall, when they are delivered by intravesical instillation.

RESULTS

Results indicate that for a laser power of 0.6 W and GNR volume fraction of 0.01%, Case 2 and 3 were successful in achieving complete tumour eradication after 330 and 470 s of laser irradiation, respectively. Case 1 failed to form complete tumour damage when the GNRs are concentrated at the tumour centre but managed to produce complete tumour damage if the spread of GNRs is wider. Results from Case 2 also demonstrated a different heating profile from Case 1, suggesting that thermal ablation during GNR-PTT is dependant on the GNRs distribution inside the tumour. Case 3 shows similar results to Case 2 whereby gradual but uniform heating is observed. Cases 2 and 3 show that uniformly heating the tumour can reduce damage to the surrounding tissues.

CONCLUSIONS

Different GNR distribution associated with the different methods of introducing GNRs to the bladder during GNR-PTT affect the treatment outcome of bladder cancer in mice. Insufficient spreading during intratumoural injection of GNRs can render the treatment ineffective, while administered via intravesical instillation. GNR distribution achieved through intravesical instillation present some advantages over intratumoural injection and is worthy of further exploration.

Carbohydrate ligands-directed active tumor targeting of combinatorial chemotherapy/phototherapy-based nanomedicine: A review

Phototherapies or light mediated therapies, including mutually photothermal and photodynamic therapy that encompass irradiation of the target organs with light, have been widely employed as minimally invasive approach associated with negligible drug resistance for eradicating multiple tumors with minimal hazards to normal organs. Despite all these advantages, many obstacles in phototherapy hinder progress toward clinical application. Therefore, researchers have developed nano-particulate delivery systems integrated with phototherapy and therapeutic cytotoxic drugs to overcome these obstacles and achieve maximum efficacy in cancer treatment. Active targeting ligands were integrated into their surfaces to improve the selectivity and tumor targeting ability, enabling easy binding and recognition by cellular receptors overexpressed on the tumor tissue compared to normal ones. This enhances intratumoral accumulation with minimal toxicity on the adjacent normal cells. Various active targeting ligands, including antibodies, aptamers, peptides, lactoferrin, folic acid and carbohydrates, have been explored for the targeted delivery of chemotherapy/phototherapy-based nanomedicine. Among these ligands, carbohydrates have been applied due to their unique features that ameliorate the bioadhesive, noncovalent conjugation to biological tissues. In this review, the up-to-date techniques of employing carbohydrates active targeting ligands will be highlighted concerning the surface modification of the nanoparticles for ameliorating the targeting ability of the chemo/phototherapy.

Manipulating Host-Guest Charge Transfer of a Water-Soluble Double-Cavity Cyclophane for NIR-II Photothermal Therapy

Water-soluble small organic photothermal agents (PTAs) over NIR-II biowindow (1000-1350 nm) are highly desirable, but the rarity greatly limits their applications. Based on a water-soluble double-cavity cyclophane GBox-4⁴⁺ , we report a class of host-guest charge transfer (CT) complexes as structurally uniform PTAs for NIR-II photothermal therapy. As a result of its high electron-deficiency, GBox-4⁴⁺ can bind different electron-rich planar guests with a 1 : 2 host/guest stoichiometry to readily tune the CT absorption band that extends to the NIR-II region. When using a diaminofluorene guest substituted with an oligoethylene glycol chain, the host-guest system realized both good biocompatibility and enhanced photothermal conversion at 1064 nm, and was then exploited as a high-efficiency NIR-II PTA for cancer cell and bacterial ablation. This work broadens the potential applications of host-guest cyclophane systems and provides a new access to bio-friendly NIR-II photoabsorbers with well-defined structures.

Triphenylphosphonium conjugated gold nanotriangles impact Pi3K/AKT pathway in breast cancer cells: a photodynamic therapy approach

Although gold nanoparticles based photodynamic therapy (PDT) were reported to improve efficacy and specificity, the impact of surface charge in targeting cancer is still a challenge. Herein, we report gold nanotriangles (AuNTs) tuned with anionic and cationic surface charge conjugating triphenylphosphonium (TPP) targeting breast cancer cells with 5-aminoleuvinic acid (5-ALA) based PDT, in vitro. Optimized surface charge of AuNTs with and without TPP kill breast cancer cells. By combining, 5-ALA and PDT, the surface charge augmented AuNTs deliver improved cellular toxicity as revealed by MTT, fluorescent probes and flow cytometry. Further, the 5-ALA and PDT treatment in the presence of AuNTs impairs cell survival Pi3K/AKT signaling pathway causing mitochondrial dependent apoptosis. The cumulative findings demonstrate that, cationic AuNTs with TPP excel selective targeting of breast cancer cells in the presence of 5-ALA and PDT.

Cancer Treatment Using Different Shapes of Gold-Based Nanomaterials in Combination with Conventional Physical Techniques

The conventional methods of cancer treatment and diagnosis, such as radiotherapy, chemotherapy, and computed tomography, have developed a great deal. However, the effectiveness of such methods is limited to the possible failure or collateral effects on the patients. In recent years, nanoscale materials have been studied in the field of medical physics to develop increasingly efficient methods to treat diseases. Gold nanoparticles (AuNPs), thanks to their unique physicochemical and optical properties, were introduced to medicine to promote highly effective treatments. Several studies have confirmed the advantages of AuNPs such as their biocompatibility and the possibility to tune their shapes and sizes or modify their surfaces using different chemical compounds. In this review, the main properties of AuNPs are analyzed, with particular focus on star-shaped AuNPs. In addition, the main methods of tumor treatment and diagnosis involving AuNPs are reviewed.

Plasmonic hot carrier injection from single gold nanoparticles into topological insulator Bi2Se3 nanoribbons

Plasmonic gold nanoparticles injecting hot carriers into the topological insulator (TI) interface of Bi₂Se₃ nanoribbons are studied by resonant Raman spectroscopy. We resolve the impact of individual gold particles with sizes ranging from 140 nm down to less than 40 nm on the topological surface states of the nanoribbons. In resonance at 1.96 eV (633 nm), we find distinct phonon renormalization in the E_g²- and A_1g²-modes that can be associated with plasmonic hot carrier injection. The phonon modes are strongly enhanced by a factor of 350 when tuning the excitation wavelengths into interband transition and in resonance with the surface plasmon of gold nanoparticles. At 633 nm wavelength, a plasmonic enhancement factor of 18 is observed indicating a contribution of hot carriers injected from the gold nanoparticles into the TI interface. Raman studies as a function of gold nanoparticle size reveal the strongest hot carrier injection for particles with size of 108 nm in agreement with the resonance energy of its surface plasmon. Hot carrier injection opens the opportunity to locally control the electronic properties of the TI by metal nanoparticles attached to the surface of nanoribbons.

Antibody-modified Gold Nanobiostructures: Advancing Targeted Photodynamic Therapy for Improved Cancer Treatment

Photodynamic therapy (PDT) is an innovative, non-invasive method of treating cancer that uses light-activated photosensitizers to create reactive oxygen species (ROS). However, challenges associated with the limited penetration depth of light and the need for precise control over photosensitizer activation have hindered its clinical translation. Nanomedicine, particularly gold nanobiostructures, offers promising solutions to overcome these limitations. This paper reviews the advancements in PDT and nanomedicine, focusing on applying antibody-modified gold nanobiostructures as multifunctional platforms for enhanced PDT efficacy and improved cancer treatment outcomes. The size, shape, and composition of gold nanobiostructures can significantly influence their PDT efficacy, making synthetic procedures crucial. Functionalizing the surface of gold nanobiostructures with various molecules, such as antibodies or targeting agents, bonding agents, PDT agents, photothermal therapy (PTT) agents, chemo-agents, immunotherapy agents, and imaging agents, allows composition modification. Integrating gold nanobiostructures with PDT holds immense potential for targeted cancer therapy. Antibody-modified gold nanobiostructures, in particular, have gained significant attention due to their tunable plasmonic characteristics, biocompatibility, and surface functionalization capabilities. These multifunctional nanosystems possess unique properties that enhance the efficacy of PDT, including improved light absorption, targeted delivery, and enhanced ROS generation. Passive and active targeting of gold nanobiostructures can enhance their localization near cancer cells, leading to efficient eradication of tumor tissues upon light irradiation. Future research and clinical studies will continue to explore the potential of gold nanobiostructures in PDT for personalized and effective cancer therapy. The synthesis, functionalization, and characterization of gold nanobiostructures, their interaction with light, and their impact on photosensitizers' photophysical and photochemical properties, are important areas of investigation. Strategies to enhance targeting efficiency and the evaluation of gold nanobiostructures in vitro and in vivo studies will further advance their application in PDT. The integrating antibody-modified gold nanobiostructures in PDT represents a promising strategy for targeted cancer therapy. These multifunctional nanosystems possess unique properties that enhance PDT efficacy, including improved light absorption, targeted delivery, and enhanced ROS generation. Continued research and development in this field will contribute to the advancement of personalized and effective cancer treatment approaches.

Photoresponsive Inorganic Nanomaterials in Oncology

The diagnosis and treatment of cancer are continuously evolving in search of more efficient, safe, and personalized approaches. Therapies based on nanoparticles or physical stimuli-responsive substances have shown great potential to overcome the inherent shortcomings of conventional cancer therapies. In fact, nanoparticles may increase the half-life of chemotherapeutic agents or promote the targeting in cancer tissues while physical stimuli-responsive substances are more effective and safer with respect to traditional chemotherapeutic agents because of the possibility to be switched on only when needed. These 2 approaches can be combined by exploiting the ability of some inorganic nanomaterials to be activated by light, ultrasounds, magnetic fields, or ionizing radiations. Albeit the development of stimuli-responsive materials is still at the early stages, research in this field is rapidly growing since they have important advantages with respect to organic nanoparticles or molecular substances, like higher stability, and higher efficiency in converting the stimulus in heat or, in some cases, reactive oxygen species. On the other hand, the translation process is slowed down by issues related to safety and quality of the formulations. This literature review summarizes the current advancements in this research field, analysing the most promising materials and applications.

Development of a Novel Electrochemical Sensor Based on Gold Nanoparticle-Modified Carbon-Paste Electrode for the Detection of Congo Red Dye

In this study, gold nanoparticles (AuNPs) were electrodeposited on samples of a carbon-paste electrode (CPE) with different thicknesses. The prepared AuNPs were characterized using different analysis techniques, such as FTIR, UV-Vis, SEM, EDX, TEM images, and XRD analysis. The fabricated modified electrode AuNPs/CPE was used for the sensitive detection of Congo red (CR) dye. Electrochemical sensing was conducted using square-wave voltammetry (SWV) in a 0.1 M acetate buffer solution at pH 6.5. The proposed sensor exhibited high efficiency for the electrochemical determination of CR dye with high selectivity and sensitivity and a low detection limit of 0.07 μM in the concentration range of 1-30 μM and 0.7 μM in the concentration range of 50-200 μM. The practical application of the AuNPs/CPE was verified by detecting CR dye in various real samples involving jelly, candy, wastewater, and tap water. The calculated recoveries (88-106%) were within the acceptable range.

Nanoparticles in Drug Delivery: From History to Therapeutic Applications

Current research into the role of engineered nanoparticles in drug delivery systems (DDSs) for medical purposes has developed numerous fascinating nanocarriers. This paper reviews the various conventionally used and current used carriage system to deliver drugs. Due to numerous drawbacks of conventional DDSs, nanocarriers have gained immense interest. Nanocarriers like polymeric nanoparticles, mesoporous nanoparticles, nanomaterials, carbon nanotubes, dendrimers, liposomes, metallic nanoparticles, nanomedicine, and engineered nanomaterials are used as carriage systems for targeted delivery at specific sites of affected areas in the body. Nanomedicine has rapidly grown to treat certain diseases like brain cancer, lung cancer, breast cancer, cardiovascular diseases, and many others. These nanomedicines can improve drug bioavailability and drug absorption time, reduce release time, eliminate drug aggregation, and enhance drug solubility in the blood. Nanomedicine has introduced a new era for drug carriage by refining the therapeutic directories of the energetic pharmaceutical elements engineered within nanoparticles. In this context, the vital information on engineered nanoparticles was reviewed and conferred towards the role in drug carriage systems to treat many ailments. All these nanocarriers were tested in vitro and in vivo. In the coming years, nanomedicines can improve human health more effectively by adding more advanced techniques into the drug delivery system.

Efficient progressive algorithm for light scattering of a multilayered concentric nanoparticle

An efficient progressive methodology is presented for the computation of multi-scattering of electromagnetic waves by a multilayered concentric nanoparticle. Instead of solving a large set of system equations as reported in other works, the proposed approach utilizes a progressive algorithm which considers two adjacent shell layers at a time, marching progressively from the innermost to the outmost layer, and requires only multiplication of 4×4 matrices. The progressive algorithm yields the analytical expression for the scattering parameter of the concentric particle. Moreover, the progressive algorithm allows the scattering coefficients of a specific internal layer to be computed selectively, rather than having to calculate those of all layers of the entire particle as required by other algorithms. We show that the presented progressive method has equivalent accuracy to the well-known recursive algorithm, but it is more attractive due to its lower complexity in implementation. It is shown that light scattering of both a single solid sphere and two-layered concentric shell are special cases of the proposed methodology. Case study demonstrates that the presented methodology is useful in assisting the design of a multilayered core/shell structure with maximum forward scattering feature, indicating it is applicable to the exploration of optical phenomena of nanoparticles with numerous layers. Moreover, the present progressive algorithm is further extended to the electromagnetic scattering by an eccentric multilayered particle with inner cores displaced along a line defined by the centers of the spheres, which provides extra freedoms for the design of optical core shell spherical particles.

Diffusive Formation of Au/Ag Alloy Nanoparticles of Governed Composition in Glass

For the first time we show that the introduction of silver ions in the glass containing gold nanoparticles (NPs) and additional heat treatment of the glass in the air lead to the formation of Au/Ag alloy NPs. The proposed approach makes it possible to position localized surface plasmon resonance of the NPs by selecting the heat treatment temperature, which determines the silver proportion in the alloy NPs. This allows for expanding customizability of NPs for applications in surface-enhanced Raman scattering spectroscopy, catalysis and biochemistry. Developed technique benefits from the presence of silver in the glass in ionic form, which prevents the oxidation of silver and provides stable preparation of Au/Ag alloy NPs.

Thermochromic Smart Windows Assisted by Photothermal Nanomaterials

Thermochromic smart windows are optical devices that can regulate their optical properties actively in response to external temperature changes. Due to their simple structures and as they do not require other additional energy supply devices, they have great potential in building energy-saving. However, conventional thermochromic smart windows generally have problems with high response temperatures and low response rates. Owing to their great effect in photothermal conversion, photothermal materials are often used in smart windows to assist phase transition so that they can quickly achieve the dual regulation of light and heat at room temperature. Based on this, research progress on the phase transition of photothermal material-assisted thermochromic smart windows is summarized. In this paper, the phase transition mechanisms of several thermochromic materials (VO₂, liquid crystals, and hydrogels) commonly used in the field of smart windows are introduced. Additionally, the applications of carbon-based nanomaterials, noble metal nanoparticles, and semiconductor (metal oxygen/sulfide) nanomaterials in thermochromic smart windows are summarized. The current challenges and solutions are further indicated and future research directions are also proposed.

Icosahedral gold nanoparticles decorated with hexon protein: a surrogate for adenovirus serotype 5

Abstract

The development of synthetic particles that emulate real viruses in size, shape, and chemical composition is vital to the development of imprinted polymer-based sorbent materials (molecularly imprinted polymers, MIPs). In this study, we address surrogates for adenovirus type 5 (Adv 5) via the synthesis and subsequent modification of icosahedral gold nanoparticles (iAuNPs) decorated with the most abundant protein of the Adv 5 (i.e., hexon protein) at the surface. CTAB-capped iAuNPs with dimensions in the range of 40–90 nm were synthesized, and then CTAB was replaced by a variety of polyethylene glycols (PEGs) in order to introduce suitable functionalities serving as anchoring points for the attachment of the hexon protein. The latter was achieved by non-covalent linking of the protein to the iAuNP surface using a PEG without reactive termination (i.e., methoxy PEG thiol, mPEG-SH, Mn=800). Alternatively, covalent anchoring points were generated by modifying the iAuNPs with a bifunctional PEG (i.e., thiol PEG amine, SH-PEG-NH₂) followed by the addition of glutaraldehyde. X-ray photoelectron spectroscopy (XPS) confirmed the formation of the anchoring points at the iAuNP surface. Next, the amino groups present in the amino acids of the hexon protein interacted with the glutaraldehyde. iAuNPs before and after PEGylation were characterized using dynamic light scattering (DLS), XPS, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and UV–Vis spectroscopy, confirming the CTAB–PEG exchange. Finally, the distinct red shift obtained in the UV–Vis spectra of the pegylated iAuNPs in the presence of the hexon protein, the increase in the hydrodynamic diameter, the change in the zeta potential, and the selective binding of the hexon-modified iAuNPs towards a hexon-imprinted polymer (HIP) confirmed success in both the covalent and non-covalent attachment at the iAuNP surface.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00216-022-04368-x.

Conjugation of Hypericin to Gold Nanoparticles for Enhancement of Photodynamic Therapy in MCF-7 Breast Cancer Cells

Breast cancer, among the different types of cancer, is one of the most diagnosed cancers and the leading cause of mortalities amongst women. Factors, including genetic and epigenetic alterations in tumors, make it resistant to therapies, which results in treatment failures and/or recurrence. Furthermore, the existing therapies have many unfavorable side effects leading to poor prognosis and reduced therapeutic outcomes. Photodynamic therapy (PDT) is one of the most effective cancer therapies with increased selectivity and specificity toward cancer cells. As a result, the use of gold nanoparticles (AuNP) further improves the effectiveness of PDT by increasing the drug loading capacity into the cells. In this study, hypericin (Hyp) photosensitizer (PS) was adsorbed on gold nanoparticles (AuNPs) by sonication to achieve physical adsorption of the PS to AuNP. The resulting compound was characterized by FTIR, Zeta potential, UV-Vis spectroscopy, and TEM. The compound was used for the PDT treatment of MCF-7 human breast cancer in vitro. Cellular responses at 12 h post-PDT at 10 J/cm2 were observed. Cellular morphology, LDH membrane integrity, ATP luminescence assay, and Annexin V/PI staining were performed. The results demonstrated typical cell death morphological features while the biochemical responses indicated increased LDH and decreased ATP levels. In conclusion, this study presents an insight into the application of advanced PDT in breast cancer cells by inducing cancer cell death in vitro via apoptosis.

Nanotechnology Advances in the Detection and Treatment of Cancer: An Overview

Over the last few years, progress has been made across the nanomedicine landscape, in particular, the invention of contemporary nanostructures for cancer diagnosis and overcoming complexities in the clinical treatment of cancerous tissues. Thanks to their small diameter and large surface-to-volume proportions, nanomaterials have special physicochemical properties that empower them to bind, absorb and transport high-efficiency substances, such as small molecular drugs, DNA, proteins, RNAs, and probes. They also have excellent durability, high carrier potential, the ability to integrate both hydrophobic and hydrophilic compounds, and compatibility with various transport routes, making them especially appealing over a wide range of oncology fields. This is also due to their configurable scale, structure, and surface properties. This review paper discusses how nanostructures can function as therapeutic vectors to enhance the therapeutic value of molecules; how nanomaterials can be used as medicinal products in gene therapy, photodynamics, and thermal treatment; and finally, the application of nanomaterials in the form of molecular imaging agents to diagnose and map tumor growth.

Recent Advances in Functionalized Nanoparticles in Cancer Theranostics

Cancer theranostics is the combination of diagnosis and therapeutic approaches for cancer, which is essential in personalized cancer treatment. The aims of the theranostics application of nanoparticles in cancer detection and therapy are to reduce delays in treatment and hence improve patient care. Recently, it has been found that the functionalization of nanoparticles can improve the efficiency, performance, specificity and sensitivity of the structure, and increase stability in the body and acidic environment. Moreover, functionalized nanoparticles have been found to possess a remarkable theranostic ability and have revolutionized cancer treatment. Each cancer treatment modality, such as MRI-guided gene therapy, MRI-guided thermal therapy, magnetic hyperthermia treatment, MRI-guided chemotherapy, immunotherapy, photothermal and photodynamic therapy, has its strengths and weaknesses, and combining modalities allows for a better platform for improved cancer control. This is why cancer theranostics have been investigated thoroughly in recent years and enabled by functionalized nanoparticles. In this topical review, we look at the recent advances in cancer theranostics using functionalized nanoparticles. Through understanding and updating the development of nanoparticle-based cancer theranostics, we find out the future challenges and perspectives in this novel type of cancer treatment.

Surface modification of gold nanoparticles with 6-mercapto-1-hexanol to facilitate dual conjugation of protoporphyrin IX and folic acid for improving the targeted photochemical internalization

Objective(s):

Photochemical internalization (PCI) is an important type of photodynamic therapy for delivering macromolecules into the cytosol by the endocytosis process. In this study, 6-mercapto-1-hexanol (MH) was used to functionalize the gold nanostructure as a primer for surface modification to improve conjugation of multi-agents such as protoporphyrin IX (Pp-IX) and folic acid with gold nanoparticles (PpIX/FA-MH-AuNP) to facilitate the photochemical internalization.

Materials and Methods:

After surface modification of AuNPs with MH, PpIX and FA are bonded to the surface of the MH-AuNPs through the coupling reaction to produce the desired conjugated AuNPs. In the next step, the synthesized nanostructures were characterized by different methods. Finally, after selecting specific concentrations, light treatments were applied and cell survival was measured based on MTT analysis. Also, in order to better study the morphology of the cells, they were stained by the Giemsa method. The SPSS 16 software was used for data analysis

Results:

By surface modification of the nanostructure with MH and then conjugation of FA to it, the incubation time of the drug in PpIX/FA-MH-AuNP was reduced from 3 hr to 30 min. Also, at each light dose, cell death in the presence of PpIX/FA-MH-AuNP was significantly reduced compared with unconjugated conditions (P<0.001). Under these conditions, the ED50 for PpIX and PpIX-MH-AuNP and PpIX/FA-MH-AuNP at a concentration of 2.5 μg/ml is 8.9, 9.1, and 6.17 min, respectively.

Conclusion:

The results show that the PCI of PpIX/FA-MH-AuNP increases the selective phototoxicity efficiency on cancer cells compared with the conventional process of photodynamic therapy.

Fundamentals and applications of metal nanoparticle- enhanced singlet oxygen generation for improved cancer photodynamic therapy

The introduction of nanotechnology in the field of Photodynamic Therapy (PDT) has proven to have great potential to overcome some of the challenges associated with traditional organic photosensitizers (PS) with respect to their solubility, drug delivery, distribution and site-specific targeting. Other focused areas in PDT involve high singlet oxygen production capability and excitability of PS by deep tissue penetrating light wavelengths. Owing to their very promising optical and surface plasmon resonance properties, combination of traditional PSs with plasmonic metallic nanoparticles like gold and silver nanoparticles results in remarkably high singlet oxygen production and extended excitation property from visible and near-infrared lights. This review summarizes the importance, fundamentals and applications of on plasmonic metallic nanoparticles in PDT. Lastly, we highlight the future prospects of these plasmonic nanoengineering strategies with or without PS combination, to have a significant impact in improving the therapeutic efficacy of cancer PDT.