Indocyanine Green-Loaded Silver Nanoparticle@Polyaniline Core/Shell Theranostic Nanocomposites for Photoacoustic/Near-Infrared Fluorescence Imaging-Guided and Single-Light-Triggered Photothermal and Photodynamic Therapy

Spectroscopic, electrical, and cytocompatibility properties of luminescent (metal nanoparticle/polyaniline) composites

In recent years, the integration of metallic nanoparticles with conductive polymers has gained significant attention for biomedical applications, including biosensors and therapeutic agents. Here, we synthesized hybrid nanocomposites of polyaniline (PANI) with copper (Cu) and silver (Ag) nanoparticles using a straightforward and scalable one-pot synthesis method. These composites were characterized by a range of techniques, including UV-vis, Fourier Transform Infrared (FTIR) spectroscopy, Zeta Potential measurements, Dynamic Light Scattering (DLS), and photoluminescence (PL). Our analysis confirmed that the composites consist of the leucoemeraldine form of PANI, which exhibited dual fluorescence emission at 342 nm (UV region) and 667 nm (visible region), highlighting a synergistic interaction between the metal nanoparticles and PANI chains. The fluorescence quantum yield was determined to be 8.80 % for Cu/PANI and 10.05 % for Ag/PANI, indicating efficient luminescence and tunability based on the metal used. The cytocompatibility was evaluated through MTT assays on four cell lines (Vero cells, macrophages, HeLa cells, and fibroblasts), showing favorable biocompatibility across most cell types. Notably, macrophages (CC50 = 353.4 μg/mL) and Vero cells (CC50 = 324.5 μg/mL) showed higher sensitivity to Cu/PANI treatment, suggesting selective interactions compared to Ag/PANI and other similar composites reported in the literature. These results demonstrate that Cu/PANI and Ag/PANI composites combine promising fluorescence properties with cytocompatibility, making them suitable candidates for diverse biomedical applications, such as fluorescent markers, biosensors, and therapeutic agents.

Photothermal/photodynamic synergistic antibacterial Nanocellulose film modified with antioxidant MXene-PANI Nanosheets

TEMPO-CNF film modified by two-dimension transition metal MXene has certain antibacterial properties. However, the problem of long-lasting stability greatly restricts the feasibility of long-term use of the composite film. Here, we introduced polyaniline (PANI) as a modifying molecule, which was electrostatically adsorbed on the surface of the MXene nanosheets to prevent its self-stacking and delay its oxidation. The modified MXene could still maintain >85 % stability after 30 days of room temperature storage. The MXene-PANI nanocellulose (MXP/CNF) film was further prepared by combining electrostatic attraction and hydrogen bonding interactions. Thanks to the synergistic effects of the photothermal conversion and photodynamic of MXene and PANI themselves, as well as the high light-trapping properties of the heterostructures, the photothermal and photodynamic efficiencies of the MXP/CNF film were greatly improved. Under the irradiation of 808 nm near-infrared light at 1.5 W/cm2, the MXP/CNF film reached a temperature of 132.9 °C within 20 s. Meanwhile, reactive oxygen species are generated to degrade 55 % of crystalline violet by modified MXene composite film under light irradiation. Compared to 15 % bacterial survival on cellulose film not modified with PANI, S. aureus and E. coli were completely killed on MXP/CNF film under light conditions. The prepared thin film materials exhibit low cytotoxicity, highlighting their potential applications in biomedicine and desalination.

Advanced Nanomaterials for Cancer Therapy: Gold, Silver, and Iron Oxide Nanoparticles in Oncological Applications

Cancer remains one of the most challenging health issues globally, demanding innovative therapeutic approaches for effective treatment. Nanoparticles, particularly those composed of gold, silver, and iron oxide, have emerged as promising candidates for changing cancer therapy. This comprehensive review demonstrates the landscape of nanoparticle-based oncological interventions, focusing on the remarkable advancements and therapeutic potentials of gold, silver, and iron oxide nanoparticles. Gold nanoparticles have garnered significant attention for their exceptional biocompatibility, tunable surface chemistry, and distinctive optical properties, rendering them ideal candidates for various cancer diagnostic and therapeutic strategies. Silver nanoparticles, renowned for their antimicrobial properties, exhibit remarkable potential in cancer therapy through multiple mechanisms, including apoptosis induction, angiogenesis inhibition, and drug delivery enhancement. With their magnetic properties and biocompatibility, iron oxide nanoparticles offer unique cancer diagnosis and targeted therapy opportunities. This review critically examines the recent advancements in the synthesis, functionalization, and biomedical applications of these nanoparticles in cancer therapy. Moreover, the challenges are discussed, including toxicity concerns, immunogenicity, and translational barriers, and ongoing efforts to overcome these hurdles are highlighted. Finally, insights into the future directions of nanoparticle-based cancer therapy and regulatory considerations, are provided aiming to accelerate the translation of these promising technologies from bench to bedside.

Photocatalytic Degradation of Methylene Blue Dye using PANI-CuFe2O4 Nano Composite

The present perspective accentuates the synthesis of PANI-CuFe2O4 (PCF) nanocomposite, and photocatalytic degradation of methylene blue (MB) dye using a synthesized composite. The stable PCF is confirmed and characterized by analytical techniques, namely, fourier transform infrared (FTIR) and X-ray photoelectron (XPS) spectroscopy, X-ray diffraction (XRD), energy-dispersive X-ray (EDX), scanning electron microscopy (SEM), and vibrating sample magnetometry (VSM) analysis. The synthesized PCF nanocomposites are significantly crystalline in nature, having magnetic saturation of 10.47 emu g-1, and monoclinic crystalline structure as well as the size of nanocomposite is 39.54 nm verified by XRD pattern. SEM analysis revealed a regular porous and rough surface of nanocomposite. In addition, the nanocomposite divulged the remarkable efficient elimination of MB dye with maximum removal of 96% with good fitting of Langmuir isotherm, indication of monolayer formation on the catalyst surface through the interaction between nanocomposite and dye molecule. The adsorption kinetics bolstered the pseudo-second-order kinetic model, suggesting the adsorption process proceeded by chemisorption. The most notable feature of the nanocomposite is the reusability and good stability after several cycles, maintaining 90% after five cycles.

Tailoring Indocyanine Green J-Aggregates for Imaging, Cancer Phototherapy, and Drug Delivery: A Review

Indocyanine green J-aggregates (ICG-Jagg) have emerged as a significant subject of interest in biomedical applications due to their unique optical properties, tunable size, and excellent biocompatibility. This comprehensive review aims to provide an in-depth exploration of ICG-Jagg, with a focus on elucidating the diverse facets of their preparation and the factors that influence the preparation process. Additionally, the review discusses their applications in biomedical diagnostics, such as imaging and contrast agents, as well as their utilization in drug delivery and various phototherapeutic interventions.

A comprehensive review on singlet oxygen generation in nanomaterials and conjugated polymers for photodynamic therapy in the treatment of cancer

A key role in lessening humanity's continuous fight against cancer could be played by photodynamic therapy (PDT), a minimally invasive treatment employed in the medical care of a range of benign disorders and malignancies. Cancerous tissue can be effectively removed by using a light source-excited photosensitizer. Singlet oxygen and reactive oxygen species are produced via the photosensitizer as a result of this excitation. In the recent past, researchers have put in tremendous efforts towards developing photosensitizer molecules for photodynamic treatment (PDT) to treat cancer. Conjugated polymers, characterized by their efficient fluorescence, exceptional photostability, and strong light absorption, are currently under scrutiny for their potential applications in cancer detection and treatment through photodynamic and photothermal therapy. Researchers are exploring the versatility of these polymers, utilizing sophisticated chemical synthesis and adaptable polymer structures to create new variants with enhanced capabilities for generating singlet oxygen in photodynamic treatment (PDT). The incorporation of photosensitizers into conjugated polymer nanoparticles has proved to be beneficial, as it improves singlet oxygen formation through effective energy transfer. The evolution of nanotechnology has emerged as an alternative avenue for enhancing the performance of current photosensitizers and overcoming significant challenges in cancer PDT. Various materials, including biocompatible metals, polymers, carbon, silicon, and semiconductor-based nanomaterials, have undergone thorough investigation as potential photosensitizers for cancer PDT. This paper outlines the recent advances in singlet oxygen generation by investigators using an array of materials, including graphene quantum dots (GQDs), gold nanoparticles (Au NPs), silver nanoparticles (Ag NPs), titanium dioxide (TiO2), ytterbium (Yb) and thulium (Tm) co-doped upconversion nanoparticle cores (Yb/Tm-co-doped UCNP cores), bismuth oxychloride nanoplates and nanosheets (BiOCl nanoplates and nanosheets), and others. It also stresses the synthesis and application of systems such as amphiphilic block copolymer functionalized with folic acid (FA), polyethylene glycol (PEG), poly(β-benzyl-L-aspartate) (PBLA10) (FA-PEG-PBLA10) functionalized with folic acid, tetra(4-hydroxyphenyl)porphyrin (THPP-(PNIPAM-b-PMAGA)4), pyrazoline-fused axial silicon phthalocyanine (HY-SiPc), phthalocyanines (HY-ZnPcp, HY-ZnPcnp, and HY-SiPc), silver nanoparticles coated with polyaniline (Ag@PANI), doxorubicin (DOX) and infrared (IR)-responsive poly(2-ethyl-2-oxazoline) (PEtOx) (DOX/PEtOx-IR NPs), particularly in NIR imaging-guided photodynamic therapy (fluorescent and photoacoustic). The study puts forward a comprehensive summary and a convincing justification for the usage of the above-mentioned materials in cancer PDT.

Platelet membrane-coated bio-nanoparticles of indocyanine green/elamipretide for NIR diagnosis and antioxidant therapy in acute kidney injury

Acute kidney injury (AKI) is a prevalent condition in critically ill patients that is often associated with significant morbidity and mortality. As the lack of effective early diagnosis methods often delays AKI treatment, there is currently no definitive clinical intervention available. In this study, we aimed to address these challenges by developing a nano-system called Platelet membranes-ICG-SS31-PLGA (PISP), which was designed to selectively target to the kidney site, taking advantage of the natural tendency of platelets to accumulate at sites of vascular injury. This approach allowed for the accumulation of PISP within the kidney as the disease progresses. By incorporating ICG, the in vivo distribution of PISP can be observed for NIR diagnosis of AKI. This non-invasive imaging technique holds great promise for early detection and monitoring of AKI. Furthermore, Elamipretide (SS31) acts as a mitochondria-targeted antioxidant that protects against mitochondrial damage and reduces oxidative stress, inflammation, and apoptosis. The combination of diagnostic and therapeutic capabilities within a single nano-system makes the PISP approach a valuable tool for addressing AKI. This intervention helps to prevent the deterioration of AKI and promotes the recovery. STATEMENT OF SIGNIFICANCE.

ICG-based laser treatments for ophthalmic diseases: Toward their safe and rapid strategy

The eye is a very important organ, and keratitis, corneal neovascularization, floaters, age-related macular degeneration, and other vision problems have seriously affected people's quality of life. Among the ophthalmic treatments, laser photocoagulations have been proposed and have shown therapeutic effects in clinical settings. However, corneal thinning and bleeding lesions induced by laser damage have led to limit its applications. To treat the issues of traditional hyperthermia treatments, photosensitizers [e.g., indocyanine green (ICG)] have been investigated to increase the therapeutic effects of corneal neovascularization and choroidal neovascularization. In the recent study, with the help of ICG, laser-induced nanobubble was proposed to treat vitreous opacities. The developed strategies could enlarge the effect of laser irradiation and reduce the side effects, so as to expand the scope of laser treatments in clinical ophthalmic diseases.

Assembly of fluorophore J-aggregates with nanospacer onto mesoporous nanoparticles for enhanced photoacoustic imaging

Many fluorophores, such as indocyanine green (ICG), have poor photostability and low photothermal efficiency hindering their wide application in photoacoustic (PA) tomography. In the present study, a supramolecular assembly approach was used to develop the hybrid nanoparticles (Hy NPs) of ICG and porous silicon (PSi) as a novel contrast agent for PA tomography. ICG was assembled on the PSi NPs to form J-aggregates within 30 min. The Hy NPs presented a red-shifted absorption, improved photothermal stability, and enhanced PA performance. Furthermore, 1-dodecene (DOC) was assembled into the NPs as a 'nanospacer', which enhanced non-radiative decay for increased thermal release. Compared to the Hy NPs, adding DOC into the Hy NPs (DOC-Hy) increased the PA signal by 83%. Finally, the DOC-Hy was detectable in PA tomography at 1.5 cm depth in tissue phantom even though its concentration was as low as 6.25 µg/mL, indicating the potential for deep tissue PA imaging.

Near-infrared photodynamic and photothermal co-therapy based on organic small molecular dyes

Near-infrared (NIR) organic small molecule dyes (OSMDs) are effective photothermal agents for photothermal therapy (PTT) due to their advantages of low cost and toxicity, good biodegradation, and strong NIR absorption over a wide wavelength range. Nevertheless, OSMDs have limited applicability in PTT due to their low photothermal conversion efficiency and inadequate destruction of tumor regions that are nonirradiated by NIR light. However, they can also act as photosensitizers (PSs) to produce reactive oxygen species (ROS), which can be further eradicated by using ROS-related therapies to address the above limitations of PTT. In this review, the synergistic mechanism, composition, and properties of photodynamic therapy (PDT)-PTT nanoplatforms were comprehensively discussed. In addition, some specific strategies for further improving the combined PTT and PDT based on OSMDs for cancer to completely eradicate cancer cells were outlined. These strategies include performing image-guided co-therapy, enhancing tumor infiltration, increasing H2O2 or O2 in the tumor microenvironment, and loading anticancer drugs onto nanoplatforms to enable combined therapy with phototherapy and chemotherapy. Meanwhile, the intriguing prospects and challenges of this treatment modality were also summarized with a focus on the future trends of its clinical application.

Design and synthesis of cancer-cell-membrane-camouflaged hemoporfin-Cu9S8 nanoagents for homotypic tumor-targeted photothermal-sonodynamic therapy

Multimodal therapies have aroused great interest in tumor therapy due to their highly effective antitumor effect. However, immune clearance limits the practical application of nanoagents-based multimodal therapies. To solve this problem, we have designed hemoporfin-Cu₉S₈ hollow nanospheres camouflaged with the CT26 cell membrane (CCM) as a model of multifunctional agents, achieving homologous-targeted synergistic photothermal therapy (PTT) and sonodynamic therapy (SDT). Hollow Cu₉S₈ as photothermal agents and carriers have been obtained through sulfurizing cuprous oxide (Cu₂O) nanoparticles through "Kirkendall effect", and they exhibit hollow nanospheres structure with a size of ∼200 nm. Then, Cu₉S₈ nanospheres could be used to load with hemoporfin sonosensitizers, and then hemoporfin-Cu₉S₈ nanospheres (abbreviated as H-Cu₉S₈) can be further surface-camouflaged with CCM. H-Cu₉S₈@CCM nanospheres exhibit a broad photoabsorption in the range of 700-1100 nm and high photothermal conversion efficiency of 39.8% under 1064 nm laser irradiation for subsequent PTT. In addition, under the excitation of ultrasound, the loaded hemoporfin could generate ¹O₂ for subsequent SDT. Especially, H-Cu₉S₈@CCM NPs are featured with biocompatibility and homologous targeting capacity. When intravenously (i.v.) injected into mice, H-Cu₉S₈@CCM NPs display a higher blood circulation half-life (3.17 h, 6.47 times) and tumor accumulation amount (18.75% ID/g, 1.94 times), compared to H-Cu₉S₈ NPs (0.49 h, 9.68% ID/g) without CCM. In addition, upon 1064 nm laser and ultrasound irradiation, H-Cu₉S₈@CCM NPs can inhibit tumor growth more efficiently due to high accumulation efficiency and synergistic PTT-SDT functions. Therefore, the present study provides some insight into the design of multifunctional efficient agents for homotypic tumor-targeted therapy.

Visible Light-Responsive Selenium Nanoparticles Combined with Sonodynamic Therapy to Promote Wound Healing

In this paper, we synthesized selenium nanoparticles (SeNPs) that could be effectively excited by pure yellow light (YL) source to enhance antibacterial ability. Meanwhile, YL could also play the role of anti-inflammatory and promote wound healing. In addition, in order to overcome the problem of low penetration depth of photodynamic therapy (PDT), SeNPs were encapsulated with polyethylenimine (PEI), then modified with the sound sensitive agent indocyanine green (ICG), realizing the combined photoacoustic therapy to promote the healing of wounds infected by drug-resistant bacteria. The antibacterial efficiency of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli) reached more than 99% in in vitro and in vivo experiments within 10 min, which could safely and quickly kill drug-resistant bacteria to repair and heal wounds.

Nanocomposite multifunctional hyaluronic acid hydrogel with photothermal antibacterial and antioxidant properties for infected wound healing

Bacterial infection and subsequent reactive oxygen species (ROS) damage are major factors that delay wound healing in infected skin. Recently, photothermal therapy (PTT), as a new antibacterial method, has shown great advantages in the treatment of infected skin wound. Antibacterial and antioxidant hydrogels can reduce bacterial colonization and infection, scavenge ROS, relieve inflammation, and accelerate wound healing. In this study, an enzyme-crosslinked hyaluronic acid-tyramine (HT) hydrogel loaded with antioxidant and photothermal silver nanoparticles (AgNPs), named HTA, was developed as functional wound dressing to promote the infected skin wound healing. Natural antioxidant tannic acids (TA) were used as both reducing and stabilizing agents to facilely synthesize the silver nanoparticles capped with TA (AgNPs@TA). The incorporation of AgNPs@TA significantly enhanced the antioxidant, antibacterial, photothermal antibacterial, adhesive, and hemostatic abilities of the resulted HTA hydrogel. Besides, HTA hydrogel has rapid gelation, well injection and biocompatibility. In vivo results on the Staphylococcus aureus and Escherichia coli co-infected mouse skin wound model showed that HTA_0.4 (containing 0.4 mg/mL AgNPs@TA) hydrogel combined with near infrared ray radiation highly alleviated inflammation, promoted angiogenesis, and accelerated the healing process. Therefore, this nanocomposite hydrogel wound dressing with antibacterial and antioxidant capabilities has great application potential in the treatment of infected skin wounds.

Photothermally Controlled Drug Release of Poly(d,l-lactide) Nanofibers Loaded with Indocyanine Green and Curcumin for Efficient Antimicrobial Photodynamic Therapy

Chronic wound infections with antibiotic-resistant bacteria have become a significant problem for modern healthcare systems since they are often associated with high costs and require profound topical wound management. Successful wound healing is achieved by reducing the bacterial load of the wound and providing an environment that enhances cell growth. In this context, nanofibers show remarkable success because their structure offers a promising drug delivery platform that can mimic the native extracellular matrix and accelerate cell proliferation. In our study, single-needle electrospinning, a versatile and cost-efficient technique, was used to shape polymers into an applicable and homogeneous fleece capable of a photothermally triggered drug release. It was combined with antimicrobial photodynamic therapy, a promising procedure against resistant bacteria. Therefore, poly(d,l-lactide) nanofibers loaded with curcumin and indocyanine green (ICG) were produced for local antimicrobial treatment. The mesh had a homogeneous structure, and the nanofibers showed a smooth surface. Recordings with a thermal camera showed that near-infrared light irradiation of ICG increased the temperature (>44 °C) in the surrounding medium. Release studies confirmed more than 29% enhanced curcumin release triggered by elevated temperature. The antimicrobial activity was tested against the gram-positive strain Staphylococcus saprophyticus subsp. bovis and the gram-negative strain Escherichia coli DH5 alpha. The nanofibers loaded with both photosensitizers and irradiated with both wavelengths reduced the bacterial viability (~4.4 log₁₀, 99.996%) significantly more than the nanofibers loaded with only one photosensitizer (<1.7 log₁₀, 97.828%) or irradiated with only one wavelength (<2.0 log₁₀, 98.952%). In addition, our formulation efficiently eradicated persistent adhered bacteria by >4.3 log₁₀ (99.995%), which was also confirmed visually. Finally, the produced nanofibers showed good biocompatibility, proven by the cellular viability of mouse fibroblasts (L929). The data demonstrate that we have developed a new economic nanofiber formulation, which offers a triggered drug release, excellent antimicrobial properties, and good biocompatibility.

Review on Metal-Based Theranostic Nanoparticles for Cancer Therapy and Imaging

Theranostic agents are promising due to their ability to diagnose, treat and monitor different types of cancer using a variety of imaging modalities. The advantage specifically of nanoparticles is that they can accumulate easily at the tumor site due to the large gaps in blood vessels near tumors. Such high concentration of theranostic agents at the target site can lead to enhancement in both imaging and therapy. This article provides an overview of nanoparticles that have been used for cancer theranostics, and the different imaging, treatment options and signaling pathways that are important when using nanoparticles for cancer theranostics. In particular, nanoparticles made of metal elements are emphasized due to their wide applications in cancer theranostics. One important aspect discussed is the ability to combine different types of metals in one nanoplatform for use as multimodal imaging and therapeutic agents for cancer.

Micropattern of Silver/Polyaniline Core-Shell Nanocomposite Achieved by Maskless Optical Projection Lithography

With the development of device miniaturization, a flexible and fast preparation method is in demand for achieving microstructures with desired patterns. We develop a novel photoreduction-polymerization method for preparing conductive metal-polymer patterns. Ag/polyaniline (PANI) nanocomposites have been successfully synthesized by maskless optical projection lithography (MOPL) technology, which is based on multiphoton absorption and the localized surface plasmon resonance (LSPR) effect. The individualized design and synthesis of the nanocomposite patterns at the micro-nano scale are flexibly realized on a variety of substrates. The surface-enhanced Raman scattering (SERS) effect of Rhodamine 6G (R6G) is demonstrated on the microstructure of a square maze-shaped Ag/PANI nanocomposite. The electrical conductivity of the as-prepared nanocomposite is obtained. The preparation protocol proposed in this study opens up new avenues for the fabrication of micro-nano devices such as sensors and detectors.

Indocyanine Green Performance Enhanced System for Potent Photothermal Treatment of Bacterial Infection

The instability in solution and aggregation-induced self-quenching of indocyanine green (ICG) have weakened its fluorescence and photothermal properties, thus inhibiting its application in practice. In this study, the cationic and anionic liposomes containing ICG were prepared based on 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-glycerol (DPPG), respectively. Molecular dynamics (MD) simulations demonstrate that ICG molecules are better distributed in the membranes of cationic DOTAP-based liposomes, leading to a superior fluorescence and photothermal performance. The liposomal ICG also shows the physical and photothermal stability during irradiation and long-term storage. On this basis, the prepared DOTAP-based liposomal ICG was encapsulated in the self-healing hydrogel formed by guar gum through the borate/diol interaction. The proposed liposomal ICG-loaded hydrogel can not only convert near-infrared (NIR) light into heat effectively but also repair itself without external assistance, which will realize potent photothermal therapy (PTT) against bacterial infection and provide the possibility for meeting the rapidly growing needs of modern medicine.

Acidity-Activatable Nanoparticles with Glucose Oxidase-Enhanced Photoacoustic Imaging and Photothermal Effect, and Macrophage-Related Immunomodulation for Synergistic Treatment of Biofilm Infection

The pH-responsive theragnostics exhibit great potential for precision diagnosis and treatment of diseases. Herein, acidity-activatable nanoparticles of GB@P based on glucose oxidase (GO) and polyaniline are developed for treatment of biofilm infection. Catalyzed by GO, GB@P triggers the conversion of glucose into gluconic acid and hydrogen peroxide (H₂ O₂ ), enabling an acidic microenvironment-activated simultaneously enhanced photothermal (PT) effect/amplified photoacoustic imaging (PAI). The synergistic effects of the enhanced PT efficacy of GB@P and H₂ O₂ accelerate biofilm eradication because the penetration of H₂ O₂ into biofilm improves the bacterial sensitivity to heat, and the enhanced PT effect destroys the expressions of extracellular DNA and genomic DNA, resulting in biofilm destruction and bacterial death. Importantly, GB@P facilitates the polarization of proinflammatory M1 macrophages that initiates macrophage-related immunity, which enhances the phagocytosis of macrophages and secretion of proinflammatory cytokines, leading to a sustained bactericidal effect and biofilm eradication by the innate immunomodulatory effect. Accordingly, the nanoplatform of GB@P exhibits the synergistic effects on the biofilm eradication and bacterial residuals clearance through a combination of the enhanced PT effect with immunomodulation. This study provides a promising nanoplatform with enhanced PT efficacy and amplified PAI for diagnosis and treatment of biofilm infection.

H2O2/pH Dual-Responsive Biomimetic Nanoenzyme Drugs Delivery System for Enhanced Tumor Photodynamic Therapy

Phototherapy has been recognized as a photochemical process to treat tumor via induce cancer cells necrosis and death, with minimal invasiveness, higher selectivity, and few side effects. However, the therapy effects of phototherapy are often compromised by the hypoxia, high levels of hydrogen peroxide, and glutathione of tumor microenvironment (TME). Therefore, we constructed a catalase-like activity bionic metal-organic framework drugs delivery system (FA-EM@MnO₂/ZIF-8/ICG) with tumor microenvironment controllable releasing. In this system, photosensitizer indocyanine green (ICG) was introduced into zeolite imidazole salt skeleton 8 (ZIF-8) by one-step methods, forming ZIF-8/ICG nano-platform, which can effectively avoid ICG-induced phototoxicity and aggregation-induced quenching during transport. MnO₂ with catalase-like activity was coated on the surface of ZIF-8/ICG nano-platform, which made it have the ability of self-supplying O₂ under the condition of H₂O₂ in TME. Exposure under near-infrared light can alleviate the anoxic TME, thus improving the phototherapy efficiency. In addition, folate-functionalized erythrocyte membrane is coated on the surface of MnO₂/ZIF-8/ICG, which can endow FA-EM@MnO₂/ZIF-8/ICG with the ability of targeted drug administration and immune elimination avoidance. Therefore, FA-EM@MnO₂/ZIF-8/ICG nano-platform has the catalase-like activity, which can alleviate the oxidative stress state of TME and provide a beneficial environment for photodynamic therapy of tumor.

SPECT/CT Imaging of 111Ag for the Preclinical Evaluation of Silver-Based Antimicrobial Nanomedicines

With the growing interest in developing silver-based antimicrobials, there is a need to better understand the behavior of silver within biological systems. To address this, we showed that single-photon emission computed tomography (SPECT) is a suitable method to noninvasively image 111Ag-labeled compounds in mice. Formed by neutron irradiation of palladium foil, 111Ag can be rapidly isolated with a high degree of purity and stably incorporated into antimicrobial silver nanoparticles. The imaging showed that nanoparticles are retained in the lungs for up to 48 h following intratracheal instillation, with limited uptake into the systemic circulation or organs of the reticuloendothelial system. Furthermore, in a mouse model of pulmonary Pseudomonas aeruginosa infection, the nanoparticles reduced the bacterial burden by 11.6-fold without inducing the production of pro-inflammatory mediators. Overall, SPECT imaging with 111Ag is a useful tool for noninvasively visualizing the biodistribution of silver-containing compounds in rodents. This knowledge of how silver nanoparticles distribute in vivo can be used to predict their therapeutic efficacy.

An efficient aggregation-induced electrochemiluminescent immunosensor by using TiO2 nanoparticles as coreaction accelerator and energy donor for aflatoxin B1 detection

Herein, we fabricated a label-free ECL immunosensor for aflatoxin B₁ (AFB₁) detection. In this system, a small organic aggregation-induced electrochemiluminescence luminophore, 2,5-di-tetraphenylethylene-ylthiazolo [5,4-d] thiazole, was designed, named TPETTZ. Polyaniline-wrapped TiO₂ nanoparticles (PANI/TiO₂ NPs) complex was synthesized through one-step in situ oxidation polymerization of aniline, and performed excellent electrical conductivity and abundant amino groups. As an ECL accelerator, TiO₂ nanoparticles (TiO₂ NPs) promoted the oxidation of tri-n-propylamine (TPA) to generate more TPA^•; in addition, it also acted as a donor to improve the ECL intensity of TPETTZ (acceptor) through electrochemiluminescence resonance energy transfer (ECL-RET). Encouraged by the above, under the existence of TPA, TPETTZ displayed a strong and continuously stable ECL_anode signal due to the introduction of PANI/TiO₂ NPs. Therefore, the immunosensor was constructed for AFB₁ detection based on the quenching effect of target on the ECL signal, and a linearly decreasing ECL signal was obtained as the increasement of AFB₁ in the range of 75 fg/mL to 100 ng/mL, with a lower detection limit of 27.5 fg/mL. Moreover, the as-prepared sensing platform performed a satisfactory anti-interference, stability, and reproducibility, and appeared a good accuracy in walnut sample analysis, presenting a promising application in the future.

Contact-Free Remote Manipulation of Hydrogel Properties Using Light-Triggerable Nanoparticles: A Materials Science Perspective for Biomedical Applications

Considerable progress has been made in synthesizing "intelligent", biodegradable hydrogels that undergo rapid changes in physicochemical properties once exposed to external stimuli. These advantageous properties of stimulus-triggered materials make them highly appealing to diverse biomedical applications. Of late, research on the incorporation of light-triggered nanoparticles (NPs) into polymeric hydrogel networks has gained momentum due to their ability to remotely tune hydrogel properties using facile, contact-free approaches, such as adjustment of wavelength and intensity of light source. These multi-functional NPs, in combination with tissue-mimicking hydrogels, are increasingly being used for on-demand drug release, preparing diagnostic kits, and fabricating smart scaffolds. Here, the authors discuss the atomic behavior of different NPs in the presence of light, and critically review the mechanisms by which NPs convert light stimuli into heat energy. Then, they explain how these NPs impact the mechanical properties and rheological behavior of NPs-impregnated hydrogels. Understanding the rheological behavior of nanocomposite hydrogels using different sophisticated strategies, including computer-assisted machine learning, is critical for designing the next generation of drug delivery systems. Next, they highlight the salient strategies that have been used to apply light-induced nanocomposites for diverse biomedical applications and provide an outlook for the further improvement of these NPs-driven light-responsive hydrogels.

NIR and Reduction Dual-Sensitive Polymeric Prodrug Nanoparticles for Bioimaging and Combined Chemo-Phototherapy

The combination of chemotherapy, photothermal therapy (PTT) and photodynamic therapy (PDT) based on a single nanosystem is highly desirable for cancer treatment. In this study, we developed a versatile Pt(IV) prodrug-based nanodrug, PVPt@Cy NPs, to realize synchronous chemotherapy, PDT and PTT and integrate cancer treatment with bioimaging. To construct PVPt@Cy NPs, the amphiphilic Pt(IV)-based polymeric prodrug PVPt was synthesized by a facile one-pot coupling reaction, and then it was used to encapsulate an optotheranostic agent (HOCyOH, Cy) via hydrophobic interaction-induced self-assembly. These NPs would disaggregate under acidic, reductive conditions and NIR irradiation, which are accompanied by photothermal conversion and reactive oxygen species (ROS) generation. Moreover, the PVPt@Cy NPs exhibited an enhanced in vitro anticancer efficiency with 808-nm light irradiation. Furthermore, the PVPt@Cy NPs showed strong NIR fluorescence and photothermal imaging in H22 tumor-bearing mice, allowing the detection of the tumor site and monitoring of the drug biodistribution. Therefore, PVPt@Cy NPs displayed an enormous potential in combined chemo-phototherapy.

Biodegradable mesoporous nanocomposites with dual-targeting function for enhanced anti-tumor therapy

Tumor-associated macrophages (TAMs), the main components of infiltrating leukocytes in tumors, often play a key role in promoting cancer development and progression. The tumor-specific microenvironment forces the phenotype of tumor-infiltrating to evolve in a direction favorable to tumor development, that is, the generation of M2-like TAMs. Consequently, the dual intervention of cancer cells and tumor microenvironment has become a research hotspot in the field of tumor immunotherapy. In this contribution, we developed pH-sensitive mesoporous calcium silicate nanocomposites (MCNs) encapsulated with indocyanine green (ICG) to enable the effective combination of photothermal therapy (PTT) and photodynamic therapy (PDT) triggered by the 808 nm near-infrared (NIR) light. The mannose and hyaluronic acid-grafted MCNs specifically targeted TAMs and tumor cells and promoted cell apoptosis both in vitro and in vivo. This paper revealed that irradiation of ICG loaded MCNs with NIR can produce a potent hyperthermia and induce abundant intracellular singlet oxygen generation in the target cells. These results suggest that the novel nanoplatform is believed to facilitate the delivery of chemotherapeutic agents to the tumor microenvironment (TME) to enhance the effects of tumor treatment.

Biocompatible Nanocarriers for Enhanced Cancer Photodynamic Therapy Applications

In recent years, the role of nanotechnology in drug delivery has become increasingly important, and this field of research holds many potential benefits for cancer treatment, particularly, in achieving cancer cell targeting and reducing the side effects of anticancer drugs. Biocompatible and biodegradable properties have been essential for using a novel material as a carrier molecule in drug delivery applications. Biocompatible nanocarriers are easy to synthesize, and their surface chemistry often enables them to load different types of photosensitizers (PS) to use targeted photodynamic therapy (PDT) for cancer treatment. This review article explores recent studies on the use of different biocompatible nanocarriers, their potential applications in PDT, including PS-loaded biocompatible nanocarriers, and the effective targeting therapy of PS-loaded biocompatible nanocarriers in PDT for cancer treatment. Furthermore, the review briefly recaps the global clinical trials of PDT and its applications in cancer treatment.

Preclinical Cancer Theranostics—From Nanomaterials to Clinic: The Missing Link

Nanomaterials with cancer‐imaging and therapeutic properties have emerged as the principal focus of nanotheranostics. The past decade has experienced a significant increase in research in the design, formulation, and preclinical and clinical trials of theranostic nanosystems. However, current theranostic nanoformulations have yet to be approved by the FDA for clinical use. Consequently, the present review focuses on the importance of the careful examination of the in vivo preclinical status of specific nanotheranostic materials as a prerequisite for their clinical translation. The scope of coverage is structured according to all of the major organic, inorganic, 2D, and hybrid nanotheranostic materials and their in vivo preclinical status. The therapeutic advantages and limitations of these materials in animal models are considered and the various strategies to enhance the biocompatibility of theranostic nanoparticles are summarized.

Optical-Property-Enhancing Novel Near-Infrared Active Niosome Nanoformulation for Deep-Tissue Bioimaging

Indocyanine green (ICG) is a clinically approved near-infrared (NIR) contrast agent used in medical diagnosis. However, ICG has not been used to its fullest for biomedical imaging applications due to its low fluorescence quantum yield, aqueous instability, concentration-dependent aggregation, and photo and thermal degradations, leading to quenching of its fluorescence emission. In the present study, a nanosized niosomal formulation, ICGNiosomes (ICGNios), is fabricated to encapsulate and protect ICG from degradation. Interestingly, compared to free ICG, the ICGNios exhibited higher fluorescence quantum yield and fluorescence emission with a bathochromic shift. Also, ICGNios nanoparticles are biocompatible, biodegradable, and readily uptaken by the cells. Furthermore, ICGNios show more enhanced fluorescence intensity through ∼1 cm thick chicken breast tissue compared to free ICG, which showed minimal emission through the same thickness of tissue. Our results suggest that ICGNios could offer a promising platform for deep-tissue NIR in vivo imaging to visualize inaccessible tissue microstructures for disease diagnosis and therapeutics.

A new biocompatible silver/polypyrrole composite with in vitro antitumor activity

We used an in situ chemical oxidation method to prepare a new composite of silver nanoparticles (AgNPs) with polypyrrole (PPy), whose properties were optimized through a 2³-factorial design of the synthesis conditions. The successful formation of the AgNPs/PPy composite was confirmed by UV-Visible and FTIR spectroscopies. Transmission electron microscopy revealed the presence of AgNPs smaller than 100 nm, dispersed into the PPy matrix. This hybrid composite exhibits a blue fluorescence emission after excitation in the ultraviolet region. In MTT assays, the AgNPs/PPy composite exhibited low cytotoxicity toward non-tumoral cell lines (fibroblast, Vero, and macrophages) and selectively inhibited the viability of HeLa cells. The AgNPs/PPy composite induces ultrastructural changes in HeLa cells that are consistent with the noticeable selectivity exhibited toward them when compared to its action against non-tumoral cell lineages. Also, the AgNPs/PPy exhibited a hemolytic activity below 14% for all blood groups tested, at concentrations up to 125 μg/mL. These results suggest that the AgNPs/PPy composite has a promising potential for use as an antitumoral agent.

Folate receptor-targeting semiconducting polymer dots hybrid mesoporous silica nanoparticles against rheumatoid arthritis through synergistic photothermal therapy, photodynamic therapy, and chemotherapy

With ideal optical properties, semiconducting polymer quantum dots (SPs) have become a research focus in recent years; a considerable number of studies have been devoted to the application of SPs in non-invasive and biosafety phototherapy with near-infrared (NIR) lasers. Nevertheless, the relatively poor stability of SPs in vitro and in vivo remains problematic. PCPDTBT was chosen to synthesize photothermal therapy (PTT) and photodynamic therapy (PDT) dual-model SPs, considering its low band gap and desirable absorption in the NIR window. For the first time, cetrimonium bromide was used as a stabilizer to guarantee the in vitro stability of SPs, and as a template to prepare SP hybrid mesoporous silica nanoparticles (SMs) to achieve long-term stability in vivo. The mesoporous structure of SMs was used as a reservoir for the hypoxia-activated prodrug Tirapazamine (TPZ). SMs were decorated with polyethylene glycol-folic acid (SMPFs) to specifically target activated macrophages in rheumatoid arthritis (RA). Upon an 808 nm NIR irradiation, the SMPFs generate intracellular hyperthermia and excessive singlet oxygen. Local hypoxia caused by molecular oxygen consumption simultaneously activates the cytotoxicity of TPZ, which effectively kills activated macrophages and inhibits the progression of arthritis. This triple PTT-PDT-chemo synergistic treatment suggests that SMPFs realize the in vivo application of SPs and may be a potential nano-vehicle for RA therapy with negligible side-toxicity.

Antibacterial Activity of Porous Gold Nanocomposites via NIR Light-Triggered Photothermal and Photodynamic Effects

Phototherapeutic approaches, including photothermal therapy (PTT) and photodynamic therapy (PDT), have become a promising strategy to combat microbial pathogens and tackle the crisis brought about by antibiotic-resistant strains. Herein, porous gold nanoparticles (AuPNs) were synthesized as photothermal agents and loaded with indocyanine green (ICG), a common photosensitizer for PDT, to fabricate a nanosystem presenting near-infrared (NIR) light-triggered synchronous PTT and PDT effects. The AuPNs can not only convert NIR light into heat with a high photothermal conversion efficiency (50.6-68.5%), but also provide a porous structure to facilely load ICG molecules. The adsorption of ICG onto AuPNs was mainly driven by electrostatic and hydrophobic interactions with the surfactant layer of AuPNs, and the aggregate state of ICG significantly enhanced its generation of reactive oxygen species. Moreover, taking advantage of its synergistic PTT and PDT effect, the hybrid nanocomposites displayed a remarkable antibacterial effect to the gram-positive pathogen Staphylococcus aureus (S. aureus) upon 808 nm laser irradiation.

Potential of Cyanine Derived Dyes in Photodynamic Therapy

Photodynamic therapy (PDT) is a method of cancer treatment that leads to the disintegration of cancer cells and has developed significantly in recent years. The clinically used photosensitizers are primarily porphyrin, which absorbs light in the red spectrum and their absorbance maxima are relatively short. This review presents group of compounds and their derivatives that are considered to be potential photosensitizers in PDT. Cyanine dyes are compounds that typically absorb light in the visible to near-infrared-I (NIR-I) spectrum range (750-900 nm). This meta-analysis comprises the current studies on cyanine dye derivatives, such as indocyanine green (so far used solely as a diagnostic agent), heptamethine and pentamethine dyes, squaraine dyes, merocyanines and phthalocyanines. The wide array of the cyanine derivatives arises from their structural modifications (e.g., halogenation, incorporation of metal atoms or organic structures, or synthesis of lactosomes, emulsions or conjugation). All the following modifications aim to increase solubility in aqueous media, enhance phototoxicity, and decrease photobleaching. In addition, the changes introduce new features like pH-sensitivity. The cyanine dyes involved in photodynamic reactions could be incorporated into sets of PDT agents.

In Situ Imaging of Cellular Reactive Oxygen Species and Caspase-3 Activity Using a Multifunctional Theranostic Probe for Cancer Diagnosis and Therapy

In this work, a multifunctional theranostic nanoprobe (Au-Ag-HM) was skillfully designed for simultaneous imaging of intracellular reactive oxygen species (ROS) and caspase-3 activity. The Au-Ag-HM was fabricated by coloading of silver nanoparticles (AgNPs) and hematoporphyrin monomethyl ether (HMME) to Au nanoflowers (AuNFs). When Au-Ag-HM was devoured by cancer cells, HepG2 cells were used as the model, and under laser irradiation, the photogenerated intracellular ROS by the photosensitizer HMME would induce the apoptosis of cancer cells. Meanwhile, the intracellular ROS triggered the oxidative etching of AgNPs on Au-Ag-HM, which led to a tremendous localized surface plasmon resonance response and scattering color changes in Au-Ag-HM, allowing in situ dark-field imaging of the ROS level in cancer cells. On the other hand, the ROS-induced activation of cellular caspase-3, which cleaved the C-peptide-containing caspase-3-specific recognition sequence (DEVD) and allowed HMME to release from the nanoprobe, resulted in a significant fluorescence recovery related to caspase-3 activity. Both photogenerated ROS and enhanced caspase-3 activity contributed to the synergistic effect of laser-mediated chemotherapy and photodynamic therapy. Therefore, the as-prepared theranostic probe could be used for simultaneous detection of cellular ROS and caspase-3 activity, distinguishing between tumor cells and normal cells, inducing the apoptosis of cancer cells, and providing a new method for diagnosis and therapy of cancer.

Multifunctional theranostic nanoparticles for biomedical cancer treatments - A comprehensive review

Modern-day search for the novel agents (their preparation and consequent implementation) to effectively treat the cancer is mainly fuelled by the historical failure of the conventional treatment modalities. Apart from that, the complexities such as higher rate of cell mutations, variable tumor microenvironment, patient-specific disparities, and the evolving nature of cancers have made this search much stronger in the latest times. As a result of this, in about two decades, the theranostic nanoparticles (TNPs) - i.e., nanoparticles that integrate therapeutic and diagnostic characteristics - have been developed. The examples for TNPs include mesoporous silica nanoparticles, luminescence nanoparticles, carbon-based nanomaterials, metal nanoparticles, and magnetic nanoparticles. These TNPs have emerged as single and powerful cancer-treating multifunctional nanoplatforms, as they widely provide the necessary functionalities to overcome the previous/conventional limitations including lack of the site-specific delivery of anti-cancer drugs, and real-time continuous monitoring of the target cancer sites while performing therapeutic actions. This has been mainly possible due to the association of the as-developed TNPs with the already-available unique diagnostic (e.g., luminescence, photoacoustic, and magnetic resonance imaging) and therapeutic (e.g., photothermal, photodynamic, hyperthermia therapy) modalities in the biomedical field. In this review, we have discussed in detail about the recent developments on the aforementioned important TNPs without/with targeting ability (i.e., attaching them with ligands or tumor-specific antibodies) and also the strategies that are implemented to increase their tumor accumulation and to enhance their theranostic efficacies for effective biomedical cancer treatments.

Electron Donor-Acceptor Effect-Induced Organic/Inorganic Nanohybrids with Low Energy Gap for Highly Efficient Photothermal Therapy

For the design and optimization of near-infrared photothermal nanohybrids, tailoring the energy gap of nanohybrids plays a crucial role in attaining a satisfactory photothermal therapeutic efficacy for cancer and remains a challenge. Herein, we report an electron donor-acceptor effect-induced organic/inorganic nanohybrid with a low energy gap (denoted as ICG/Ag/LDH) by the in situ deposition of Ag nanoparticles onto the CoAl-LDH surface, followed by the coupling of ICG. A combination study verifies that the supported Ag nanoparticles as the electron donor (D) push electrons into the conjugated system of ICG by the electronic interaction between ICG and Ag, while OH groups of LDHs as the electron acceptor (A) pull electrons from the conjugated system of ICG by hydrogen bonding (N···H-O). This induces the formation of the D-A conjugated π-system and has a strong influence on the π-conjugated system of ICG, thus leading to a prominent decrease toward the energy gap and correspondingly an ultra-long redshift (∼115 nm). The resulting ICG/Ag/LDHs show an enhanced photothermal conversion efficiency (∼45.5%) at 808 nm laser exposure, which is ∼1.6 times larger than that of ICG (∼28.4%). Such a high photothermal performance is attributed to the fact that ICG/Ag/LDHs possess a D-π-A hybrid structure and a resulting lower energy gap, thus effectively promoting nonradiative transitions and leading to enhancement of the photothermal effect. Both in vitro and in vivo results confirm the good biocompatible properties and capability of the ICG/Ag/LDHs for NIR-triggered cancer treatment. This research demonstrates a successful paradigm for the rational design and preparation of new nanohybrids through the modulation of electron donor-acceptor effect, which offers a new avenue to achieve efficient phototherapeutic agent for improving the cancer therapeutic outcomes.

Polyaniline@Au organic-inorganic nanohybrids with thermometer readout for photothermal immunoassay of tumor marker

A photothermal immunoassay using a thermometer as readout based on polyaniline@Au organic-inorganic nanohybrids was built. Temperature output is acquired due to the photothermal effect of the photothermal nanomaterial. Polyaniline@Au organic-inorganic nanohybrids were synthesized by interfacial reactions with high photothermal conversion efficiency. A sandwich structure of the immunocomplex was prepared on a microplate for determination of carcinoembryonic antigen (CEA) by polyaniline@Au organic-inorganic nanohybrids as nanolabel. The released heat based on light-to-heat conversion from the photothermal nanolabel under NIR irradiation is detectable using the thermometer. The increased temperature is directly proportional to CEA concentration. The linear range of the photothermal immunoassay is 0.20 to 25 ng mL-1 with determination limit of 0.17 ng mL-1. Polyaniline@Au organic-inorganic nanohybrids with high photothermal conversion efficiency was synthesized as labels to construct photothermal immunosensor. The sandwich-type immunoassay was built on 96 hole plate based on specific binding of antigen and antibody. Carcinoembryonic antigen in sample was detected quantitatively by thermometer readout.

Polyaniline-Coated TiO2 Nanorods for Photocatalytic Degradation of Bisphenol A in Water

Polyaniline (PANI)-wrapped TiO₂ nanorods (PANI/TiO₂), obtained through the oxidative polymerization of aniline at the surface of hydrothermally presynthesized TiO₂ nanorods, were evaluated as photocatalysts for the degradation of Bisphenol A (BPA). Fourier-transform infrared spectroscopy analysis revealed the successful incorporation of PANI into TiO₂ by the appearance of peaks at 1577 and 1502 cm^-1 that are due to the C=C and C-N stretch of the benzenoid or quinoid ring in PANI. Brunauer-Emmett-Teller analysis revealed that PANI/TiO₂ had almost double the surface area of TiO₂ (44.8999 m²/g vs 28.2179 m²/g). Transmission electron microscopy (TEM) analysis showed that TiO₂ nanorods with different diameters were synthesized. The TEM analysis showed that a thin layer of PANI wrapped the TiO₂ nanorods. X-ray photon spectroscopy survey scan of the PANI/TiO₂ nanocomposite revealed the presence of C, O, Ti, and N. Photocatalytic activity evaluation under UV radiation through the effect of key parameters, including pH, contact time, dosage, and initial concentration of BPA, was carried out in batch studies. Within 80 min, 99.7% of 5 ppm BPA was attained using the 0.2 g/L PANI/TiO₂ photocatalyst at pH 10. The quantum yield (QY) of these photocatalysts was evaluated to be 9.86 × 10^-5 molecules/photon and 2.82 × 10^-5 molecules/photon for PANI/TiO₂ and TiO₂, respectively. PANI/TiO₂ showed better performance than as-synthesized TiO₂ with a rate constant of 4.46 × 10^-2 min^-1 compared to 2.18 × 10^-2 min^-1. The rate of degradation of PANI/TiO₂ was also superior to that of TiO₂ (150 mmol/g/h vs 74.89 mmol/g/h). Nitrate ions increased the rate of degradation of BPA, while humic acid consistently inhibited the degradation of BPA. LC-MS analysis identified degradation products with m/z 213.1, 135.1, and 93.1. The PANI/TiO₂ nanocomposite was reused up to five cycles with a removal of at least 80% in the fifth cycle. LC-MS results revealed three possible BPA degradation intermediates. LC-MS analysis identified degradation products which included protonated BPA, [C₁₄H₁₃O₂ ⁺], and [C₉H₁₁O⁺]. The PANI/TiO₂ nanocomposite demonstrated superior photocatalytic activity with respect to improved QY and figure of merit and lower energy consumption.

On/off switchable epicatechin-based ultra-sensitive MRI-visible nanotheranostics - see it and treat it

Nanotechnology has a remarkable impact on the preclinical development of future medicines. However, the complicated preparation and systemic toxicity to living systems prevent them from translation to clinical applications. In the present report, we developed a polyepicatechin-based on/off switchable ultra-sensitive magnetic resonance imaging (MRI) visible theranostic nanoparticle (PEMN) for image-guided photothermal therapy (PTT) using our strategy of integrating polymerization and biomineralization into the protein template. We have exploited natural polyphenols as the near infra-red (NIR) switchable photothermal source and MnO₂ for the MRI-guided theranostics. PEMN demonstrates excellent MRI contrast ability with a longitudinal relaxivity value up to 30.01 mM^-1 s^-1. PEMN has shown great tumor inhibition on orthotopic breast tumors and the treatment could be made switchable with an on/off interchangeable mode as needed. PEMN was found to be excretable mainly through the kidneys, avoiding potential systemic toxicity. Thus, PEMN could be extremely useful for developing on-demand therapeutics via'see it and treat it' means with distinguished MRI capability and on/off switchable photothermal properties.

Recent Advances of Polyaniline-Based Biomaterials for Phototherapeutic Treatments of Tumors and Bacterial Infections

Conventional treatments fail to completely eradicate tumor or bacterial infections due to their inherent shortcomings. In recent years, photothermal therapy (PTT) has emerged as an attractive treatment modality that relies on the absorption of photothermal agents (PTAs) at a specific wavelength, thereby transforming the excitation light energy into heat. The advantages of PTT are its high efficacy, specificity, and minimal damage to normal tissues. To this end, various inorganic nanomaterials such as gold nanostructures, carbon nanostructures, and transition metal dichalcogenides have been extensively explored for PTT applications. Subsequently, the focus has shifted to the development of polymeric PTAs, owing to their unique properties such as biodegradability, biocompatibility, non-immunogenicity, and low toxicity when compared to inorganic PTAs. Among various organic PTAs, polyaniline (PANI) is one of the best-known and earliest-reported organic PTAs. Hence, in this review, we cover the recent advances and progress of PANI-based biomaterials for PTT application in tumors and bacterial infections. The future prospects in this exciting area are also addressed.

A novel multifunctional FePt/BP nanoplatform for synergistic photothermal/photodynamic/chemodynamic cancer therapies and photothermally-enhanced immunotherapy

A new multi-modal therapy agent, FePt/BP-PEI-FA nanoplatform, with FePt nanoparticles (FePt NPs) loaded onto ultrathin black phosphorus nanosheets (BPNs), has been constructed to enhance synergistic photothermal therapy (PTT), photodynamic therapy (PDT), and chemodynamic therapy (CDT) that target primary tumors. In this work, BPNs exhibit excellent photothermal and photodynamic behaviors under different wavelength laser irradiation. After polyethylenimine (PEI) modification, FePt NPs with sizes of 3-4 nm are uniformly attached onto the surface of modified BPNs via electrostatic adsorption. FePt NPs, as a ferroptosis agent, can transform endogenous H₂O₂ into reactive oxygen species (ROS) through the Fenton reaction, ultimately inducing cell death. Based on magnetic resonance imaging (MR) and thermal imaging, the as-prepared FePt/BP-PEI-FA NCs can inhibit tumor growth by achieving synergistic therapies. More significantly, combined with cytotoxic T lymphocyte-associated protein 4 (CTLA-4) checkpoint blockade, FePt/BP-PEI-FA NC-induced PTT can control both primary and untreated distant tumors' growth. Therefore, FePt/BP-PEI-FA NCs is a potential multifunctional nanoagent for effective anti-tumor applications.

Mitochondria-Targeting Organic Nanoparticles for Enhanced Photodynamic/Photothermal Therapy

Organelle-targeting techniques have been proved to be promising approaches for enhanced cancer treatment, especially phototherapy, because it can greatly improve the efficiency of photosensitizers. In this work, we designed and synthesized a mitochondria-targeting diketopyrrolopyrrole-based photosensitizer (DPP2+) for synergistic photodynamic/photothermal therapy upon irradiation. The obtained mitochondria-targeting nanoparticles (DPP2+ NPs) could produce thermal energy and singlet oxygen under 635 nm laser irradiation with ideal cytocompatibility. Importantly, DPP2+ NPs are more likely to enter the cells and target mitochondria. In in vitro and in vivo antitumor experiments, DPP2+ NPs showed highly effective antitumor effects, suggesting that mitochondria-targeting photosensitizers have potential for cancer treatment. The present work provides an alternative strategy to mitochondria-targeting molecular engineering and highlights the potential of organic nanomaterials in biomedical fields and cancer treatment.

Microcellular Environmental Regulation of Silver Nanoparticles in Cancer Therapy: A Critical Review

Silver nanoparticles (AgNPs) play significant roles in various cancer cells such as functional heterogeneity, microenvironmental differences, and reversible changes in cell properties (e.g., chemotherapy). There is a lack of targets for processes involved in tumor cellular heterogeneity, such as metabolic clampdown, cytotoxicity, and genotoxicity, which hinders microenvironmental biology. Proteogenomics and chemical metabolomics are important tools that can be used to study proteins/genes and metabolites in cells, respectively. Chemical metabolomics have many advantages over genomics, transcriptomics, and proteomics in anticancer therapy. However, recent studies with AgNPs have revealed considerable genomic and proteomic changes, particularly in genes involved in tumor suppression, apoptosis, and oxidative stress. Metabolites interact biochemically with energy storage, neurotransmitters, and antioxidant defense systems. Mechanobiological studies of AgNPs in cancer metabolomics suggest that AgNPs may be promising tools that can be exploited to develop more robust and effective adaptive anticancer therapies. Herein, we present a proof-of-concept review for AgNPs-based proteogenomics and chemical metabolomics from various tumor cells with the help of several technologies, suggesting their promising use as drug carriers for cancer therapy.