Controllable Synthesis of Gold Nanorod/Conducting Polymer Core/Shell Hybrids Toward in Vitro and in Vivo near-Infrared Photothermal Therapy

Gold Nanorods Decorated by Conjugated Microporous Polymers for Infrared Responsive Cytostatic Drug Delivery

Near-infrared (NIR) controlled drug delivery systems have drawn a lot of attention throughout the past few decades due to the deep penetration depth and comparatively minor side effects of the stimulus. In this study, we introduce an innovative approach for gastric cancer treatment by combining photothermal infrared-sensitive gold nanorods (AuNRs) with a conjugated microporous polymer (CMP) to create a drug delivery system tailored for transporting the cytostatic drug 5-fluorouracil (5-FU). CMPs are fully conjugated networks with high internal surface areas that can be precisely tailored to the adsorption and transport of active compounds through the right choice of chemical functionalities. By incorporation of surfactant-stabilized AuNRs into the CMP synthesis in dimethylformamide (DMF) the surfactant shell is destabilized and subsequently replaced by the CMP. Particularly, low initial surfactant concentrations led to uniform distribution of the AuNRs in the polymer matrix. Importantly, the integrated AuNRs maintain their plasmonic properties, as was confirmed via electron energy loss spectroscopy. Therefore, the significant photothermal properties are translated to the hybrid material as shown in a proof-of-principle experiment. Further, in an approximated gastric environment, 5-FU release studies were conducted with and without NIR stimulus. Thereby it was observed that increased Brownian motion due to the NIR irradiation not only accelerates the release but also increases the total released amount by influencing the adsorption-desorption equilibrium. This remarkable level of control of the release process underlines the immense potential of this hybrid material for precise and targeted drug delivery.

Photochemical Synthesis of Sericin-Coated Gold Nanorods and Their Antibacterial Activity under Low-Level Near-Infrared Light

Gold nanorods (GNRs) are unique nanoparticles with easily functionalized surfaces, multiple synthesis methods, photothermal conversion, and surface plasmon resonance effects. These properties make GNRs suitable for various biological applications. However, a rapid synthesis of GNRs using less toxic chemicals is needed. The photochemical method is a viable option that can synthesize GNRs quickly while using fewer chemicals. A photochemical method is reported for the synthesis of GNRs using Irgacure-2959 as a reducing agent. This method could be used to synthesize GNRs with a rod-like shape within 30 min. Additionally, GNRs were coated with sericin (GNRs-SC) to further reduce their toxicity in human dermal fibroblast adult cells. Low-level near-infrared (NIR) light was applied to enhance the photothermal therapy of both GNRs and GNRs-SC. The results showed that GNRs and GNRs-SC under low-level NIR light have enhanced antibacterial activity against Staphylococcus aureus and Escherichia coli, as well as antibiofilm activity against S. aureus. Furthermore, GNRs-SC showed good biocompatibility with antibacterial and antibiofilm activities. These results indicate that GNRs-SC are good candidates for various biological applications.

Gold nanorods as biocompatible nano-agents for the enhanced photothermal therapy in skin disorders

Rod-shaped gold nanomaterials, known as gold nanorods (GNRs), may undergo specific surface alterations, because of their straightforward surface chemistry. This feature makes them appropriate for use as functional and biocompatible nano-formulations. By optimizing the absorption of longitudinally localized surface plasmon resonance (LSPR) in the near-infrared (NIR) region, which corresponds to the NIR bio-tissue window, GNRs with appropriate modifications may improve the results of photothermal treatment (PTT). In dermatology, potential noninvasive uses of GNRs to enhance wound healing, manage infections, combat cutaneous malignancies, and remodel skin tissues via PTT have attracted research attention in recent years. In this review, the basic properties of GNRs, such as shape, size, optical performance, photothermal efficiency, and metabolism, are discussed firstly. Then, the disadvantages of using these particles in photodynamic therapy (PDT) are proposed. Next, biological applications of GNRs-based PTT are summarized in detail. Finally, the limitations and future perspectives of this research are summarized, providing a comprehensive outlook for prospective GNRs with PTT.

Intercalation of V2O5 and Polypyrrole into a Graphene Oxide Layer: A Hybrid Multifunctional Photothermal Structure for Efficient Solar Evaporation, Water Purification, Disinfection, and Power Production

Development of a hybrid multifunctional photothermal structure with multifunctional capabilities is deliberated as an effective approach for harvesting abundant solar energy for sustainable environmental applications. Achieving enhanced solar to thermal conversion efficiency utilizing a suitably designed, environmentally compatible thermal management structure however remains a significant challenge. Herein, we report the intercalation of V2O5 and polypyrrole into a graphene oxide layer to design a hybrid photothermal assembly (PPy-V2O5-GO) and its multifunctional proficiencies. The hybrid photothermal structure demonstrated synergistic photothermal conversion, buoyant porous structure sustaining water transmission, and efficient steam release. V2O5 and polypyrrole-intercalated optimized graphene oxide structure attained an evaporation rate of 1.9 kg m-2 h-1 with a conversion efficiency of 92% under 1 sun solar radiation. At maximum, the assembly's surface temperature hit 64 ± 2 °C, suggesting its suitability as a solar water purifier. Outdoor experiments suggest the evaporator assembly's capability to accumulate a total output of 15 kg m-2 over a single day. Cell viability investigations revealed strong antimicrobial properties of PPy-V2O5-GO against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria, eliminating nearly all under 1 sun, making it a potential candidate for photothermal therapy. Furthermore, when combined with a commercial thermoelectric module, the framework displayed exceptional photothermal conversion efficiency, hinting at its potential for electrical power generation. The integration of PPy-V2O5-GO with a Bi2Te3-based thermoelectric module significantly boosted the thermoelectric generator's performance, offering an enhanced power output of 2.8 mW and a high power density of 1.24 mW/cm2, making them suitable for off-grid or remote-area application. Overall, the PPy-V2O5-GO photothermal assembly's stability, lack of leaching, effectiveness in producing pure water from seawater, antimicrobial efficacies, and recyclability make it an excellent choice for sustainable water treatment and power generation.

Research progress of nanoparticles in diagnosis and treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is among the most common malignant liver tumors. Despite progress in anticancer drugs and surgical approaches, early detection of HCC remains challenging, often leading to late-stage diagnosis where rapid disease progression precludes surgical intervention, leaving chemotherapy as the only option. However, the systemic toxicity, low bioavailability, and significant adverse effects of chemotherapy drugs often lead to resistance, rendering treatments ineffective for many patients. This article outlines how nanoparticles, following functional modification, offer high sensitivity, reduced drug toxicity, and extended duration of action, enabling precise targeting of drugs to HCC tissues. Combined with other therapeutic modalities and imaging techniques, this significantly enhances the diagnosis, treatment, and long-term prognosis of HCC. The advent of nanomedicine provides new methodologies and strategies for the precise diagnosis and integrated treatment of HCC.

Development of pH-responsive porphyran-coated gold nanorods for tumor photothermal and immunotherapy

Cancer poses a significant threat to human health, and monotherapy frequently fails to achieve optimal therapeutic outcomes. Based on this premise, porphyran (PHP), a marine polysaccharide with immunomodulatory function, was used as a framework to coat gold nanorods and construct a novel nanomedicine (PHP-MPBA-GNRs) combining photothermal therapy and immunotherapy. In this design, PHP not only maintained the dispersion stability and photothermal stability of gold nanorods but also could be released under weakly acidic conditions to activate anti-tumor immunity. In vivo studies have shown that PHP-MPBA-GNRs can effectively inhibit tumor cell proliferation and reduce metastasis under near-infrared (NIR) light irradiation. Preliminary mechanistic investigations revealed that PHP-MPBA-GNRs could increase reactive oxygen species (ROS) and induce apoptosis in cancer cells. The PHP in PHP-MPBA-GNRs can also activate dendritic cells and up-regulate the expression of co-stimulatory molecules and antigen-presenting complexes. All biological experiments, including in vivo tests, demonstrated that PHP-MPBA-GNRs achieved a combination of photothermal therapy and immunotherapy for tumors.

Shape-Regulated Photothermal-Catalytic Tumor Therapy Using Polydopamine@Pt Nanozymes with the Elicitation of an Immune Response

Recently, nanozyme-based photothermal-catalytic therapy has emerged as a promising strategy for antitumor treatment. Extensive research has focused on optimizing the catalytic activity and photothermal conversion performance of nanozymes through size, morphology, and surface property regulations. However, the biological effects of nanozymes, such as cellular uptake and cytotoxicity, resulting from their physicochemical properties, remain largely unexplored. In this study, two types of polydopamine/platinum (PDA@Pt) nanozymes, flower-like (FPDA@Pt) and mesoporous spherical-like (MPDA@Pt), to comprehensively compare their enzyme-mimicking activity, photothermal conversion capacity, and antitumor efficiency are designed. These findings revealed that FPDA@Pt exhibited superior peroxidase-like activity and higher photothermal conversion efficiency compared to MPDA@Pt. This led to enhanced production of reactive oxygen species (ROS) and increased heat generation at tumor sites. Importantly, it is observed thatthe flower-like structure of FPDA@Pt facilitated enhanced cellular uptake, leading to an increased accumulation of nanozymes within tumor cells. Furthermore, the light irradiation on tumors also triggered a series of anti-tumor immune responses, further enhancing the therapeutic efficacy. This work provides a possible design orientation for nanozyme-based photothermal-catalytic tumor therapy, highlighting the importance of considering the physicochemical properties of nanozymes to optimize their therapeutic potential in antitumor strategies.

Enhancing Phototoxicity in Human Colorectal Tumor Cells Through Nanoarchitectonics for Synergistic Photothermal and Photodynamic Therapies

Phototherapies are promising for noninvasive treatment of aggressive tumors, especially when combining heat induction and oxidative processes. Herein, we show enhanced phototoxicity of gold shell-isolated nanorods conjugated with toluidine blue-O (AuSHINRs@TBO) against human colorectal tumor cells (Caco-2) with synergic effects of photothermal (PTT) and photodynamic therapies (PDT). Mitochondrial metabolic activity tests (MTT) performed on Caco-2 cell cultures indicated a photothermal effect from AuSHINRs owing to enhanced light absorption from the localized surface plasmon resonance (LSPR). The phototoxicity against Caco-2 cells was further increased with AuSHINRs@TBO where oxidative processes, such as hydroperoxidation, were also present, leading to a cell viability reduction from 85.5 to 39.0%. The molecular-level mechanisms responsible for these effects were investigated on bioinspired tumor membranes using Langmuir monolayers of Caco-2 lipid extract. Polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS) revealed that the AuSHINRs@TBO incorporation is due to attractive electrostatic interactions with negatively charged groups of the Caco-2 lipid extract, resulting in the expansion of surface pressure isotherms. Upon irradiation, Caco-2 lipid extract monolayers containing AuSHINRs@TBO (1:1 v/v) exhibited ca. 1.0% increase in surface area. This is attributed to the generation of reactive oxygen species (ROS) and their interaction with Caco-2 lipid extract monolayers, leading to hydroperoxide formation. The oxidative effects are facilitated by AuSHINRs@TBO penetration into the polar groups of the extract, allowing oxidative reactions with carbon chain unsaturations. These mechanisms are consistent with findings from confocal fluorescence microscopy, where the Caco-2 plasma membrane was the primary site of the cell death induction process.

Photochemical outcomes triggered by gold shell-isolated nanorods on bioinspired nanoarchitectonics for bacterial membranes

Boosted by the indiscriminate use of antibiotics, multidrug-resistance (MDR) demands new strategies to combat bacterial infections, such as photothermal therapy (PTT) based on plasmonic nanostructures. PTT efficiency relies on photoinduced damage caused to the bacterial machinery, for which nanostructure incorporation into the cell envelope is key. Herein, we shall unveil the binding and photochemical mechanisms of gold shell-isolated nanorods (AuSHINRs) on bioinspired bacterial membranes assembled as Langmuir and Langmuir-Schaefer (LS) monolayers of DOPE, Lysyl-PG, DOPG and CL. AuSHINRs incorporation expanded the isotherms, with stronger effect on the anionic DOPG and CL. Indeed, FTIR of LS films revealed more modifications for DOPG and CL owing to stronger attractive electrostatic interactions between anionic phosphates and the positively charged AuSHINRs, while electrostatic repulsions with the cationic ethanolamine (DOPE) and lysyl (Lysyl-PG) polar groups might have weakened their interactions with AuSHINRs. No statistical difference was observed in the surface area of irradiated DOPE and Lysyl-PG monolayers on AuSHINRs, which is evidence of the restricted nanostructures insertion. In contrast, irradiated DOPG monolayer on AuSHINRs decreased 4.0 % in surface area, while irradiated CL monolayer increased 3.7 %. Such results agree with oxidative reactions prompted by ROS generated by AuSHINRs photoactivation. The deepest AuSHINRs insertion into DOPG may have favored chain cleavage while hydroperoxidation is the mostly like outcome in CL, where AuSHINRs are surrounding the polar groups. Furthermore, preliminary experiments on Escherichia coli culture demonstrated that the electrostatic interactions with AuSHINRs do not inhibit bacterial growth, but the photoinduced effects are highly toxic, resulting in microbial inactivation.

Redirecting Antigens by Engineered Photosynthetic Bacteria and Derived Outer Membrane Vesicles for Enhanced Cancer Immunotherapy

Significant strides have been made in the development of cancer vaccines to combat malignant tumors. However, the natural immunosuppressive environment within tumors, known as the tumor microenvironment (TME), hampers the uptake and presentation of antigens by antigen-presenting cells (APCs) within the tumor itself. This limitation results in inadequate activation of immune responses against cancer. In contrast, immune cells in peritumoral tissue maintain their normal functions. In this context, we present an interesting approach to enhance cancer immunotherapy by utilizing engineered photosynthetic bacteria (PSB) and their outer membrane vesicles (OMVPSB) to capture and transport antigens to the outer regions of the tumor. We modified PSB with maleimide (PSB-MAL), which, when exposed to near-infrared (NIR) laser-mediated photothermal therapy (PTT), induced extensive cancer cell death and the release of tumor antigens. Subsequently, the NIR-phototactic PSB-MAL transported these tumor antigens to the peripheral regions of the tumor under NIR laser exposure. Even more intriguingly, PSB-MAL-derived OMVPSB-MAL effectively captured and delivered antigens to tumor-draining lymph nodes (TDLNs). This facilitated enhanced antigen presentation by mature and fully functional APCs in the TDLNs. This intricate communication network between PSB-MAL, the OMVPSB-MAL, and APCs promoted the efficient presentation of tumor antigens in the tumor periphery and TDLNs. Consequently, there was a notable increase in the infiltration of cytotoxic T lymphocytes (CTLs) into the tumor, triggering potent antitumor immune responses in both melanoma and breast cancer models. This cascade of events resulted in enhanced suppression of tumor metastasis and recurrence, underscoring the robust efficacy of our approach. Our interesting study, harnessing the potential of bacteria and OMVs to redirect tumor antigens for enhanced cancer immunotherapy, provides a promising path toward the development of personalized cancer vaccination strategies.

Bioorthogonal Glycoengineering-Mediated Multifunctional Liquid Metal Nanoprobes for Highly Efficient Photoacoustic Imaging-Guided Photothermal/Chemotherapy of Tumor

The development of a multifunctional cancer diagnosis and treatment platform offers excellent prospects for the effective eradication of malignant solid tumors. Herein, a doxorubicin hydrochloride (DOX)-loaded tannic acid (TA)-coated liquid metal (LM) multifunctional nanoprobe was synthesized and applied as a highly efficient platform for the photoacoustic (PA) imaging-guided photothermal/chemotherapy of tumor. The multifunctional nanoprobes exhibited strong near-infrared absorption, a remarkable photothermal conversion efficiency (PCE) of 55%, and high DOX loading capacity. Combined with the large intrinsic thermal expansion coefficient of LM, highly efficient PA imaging and effective drug release were realized. The LM-based multifunctional nanoprobes were specifically adsorbed into the cancer cells and tumor tissues via glycoengineering biorthogonal chemistry. The in vitro and in vivo photothermal/chemo-anticancer activity confirmed their promising potential in cancer treatment. The subcutaneous breast tumor-bearing mice completely recovered in 5 days under light illumination with clear PA imaging presentation, which showed better antitumor outcomes than single-mode chemotherapy or photothermal therapy (PTT), while keeping side effects at a minimum. Such an LM-based PA imaging-guided photothermal/chemotherapy strategy provided a valuable platform for resistant cancer precise treatment and intelligent biomedicine.

Integrated Polypyrrole-Based Smart Clothing with Photothermal Conversion and Thermosensing Functions for Wearable Applications

Integrated smart clothing with photothermal conversion and thermosensing functions is highly desired for next-generation smart wearable applications. Conducting polymer is a promising material that possesses efficient photothermal conversion performance, great sensitivity to temperature change, and excellent processing properties. In this study, we report a new wearable material using the conducting polymer polypyrrole (PPy) as a photothermal and thermosensing layer and nonwoven fabric as flexible textiles to fabricate integrated PPy-based smart clothing (IPSC). The surface temperature of the prepared IPSC can be as high as 68.4 °C with 808 nm near-infrared (NIR) irradiation at a power destiny of 1 kW/m². Meanwhile, a temperature resolution of 1 °C can be achieved for IPSC. These superiorities are in favor of fabricating multifunctional smart wearables to satisfy the needs in future life.

Construction of core-in-shell Au@N-HCNs nanozymes for tumor therapy

Noble metals act as nanozymes that can generate reactive oxygen species (ROS) by catalysis to induce apoptosis of tumor cells for cancer therapy. But they are easy to aggregate, which will affect their further application. Carbon materials are often used as the carrier of noble metals to improve their catalytic performance. However, designing a composite structure to build an efficient carbon/noble metal hybrid nanozyme with high catalytic performance for tumor therapy is still a significant challenge. In this work, a core-in-shell structure nanozyme composed of gold nanoparticles (AuNPs) embedded in nitrogen-doped hollow carbon nanoshells (AuNPs@N-HCNs) were fabricated, which exhibited peroxidase-like (POD-like) and oxidase-like (OXD-like) activity. Compared with core-out-of-shell structure composite, the AuNPs@N-HCNs showed a better ability to generate ROS to kill tumor cells. Furthermore, AuNPs@N-HCNs also exhibited satisfactory photothermal conversion properties, which helped build a platform for photothermal therapy. Meanwhile, the enzyme activity produced by AuNPs@N-HCNs increased significantly under light irradiation. Comparing the size of AuNPs in carbon shell, 15 nm AuNPs were better than 2 nm in both enzyme-like activities and in vivo therapeutic effect. In vitro and in vivo studies demonstrated that under the synergistic effect of light-enhancing nanozyme catalysis and photothermal therapy, AuNPs@N-HCNs could induce cancer cell apoptosis and destroy tumors effectively, which provided evidence for the feasibility of tumor catalytic-photothermal treatment.

Supramolecular Core-Shell Nanoassemblies with Tumor Microenvironment-Triggered Size and Structure Switch for Improved Photothermal Therapy

Photothermal therapy (PTT) is demonstrated to be an effective methodology for cancer treatment. However, the relatively low photothermal conversion efficiency, limited tumor accumulation, and penetration still remain to be challenging issues that hinder the clinical application of PTT. Herein, the core-shell hierarchical nanostructures induced by host-guest interaction between water-soluble pillar[5]arene (WP5) and polyethylene glycol-modified aniline tetramer (TAPEG) are constructed. The pH-responsive performance endows the core-shell nanostructures with size switchable property, with an average diameter of 200 nm in the neutral pH and 60 nm in the acidic microenvironment, which facilitates not only tumor accumulation but also tumor penetration. Moreover, the structure switch of WP5⊃TAPEG under acidic microenvironment and the dual mechanism regulated extending of п conjugate, inclusion in the hydrophobic cavity of WP5 and the dense distribution in the core-shell structured assemblies, dramatically enhance the absorption in the near-infrared-II region and, further, the photothermal conversion efficiency (60.2%). The as-designed intelligent nanoplatform is demonstrated for improved antitumor efficacy via PTT.

Gold-Polymer Nanocomposites for Future Therapeutic and Tissue Engineering Applications

Gold nanoparticles (AuNPs) have been extensively investigated for their use in various biomedical applications. Owing to their biocompatibility, simple surface modifications, and electrical and unique optical properties, AuNPs are considered promising nanomaterials for use in in vitro disease diagnosis, in vivo imaging, drug delivery, and tissue engineering applications. The functionality of AuNPs may be further expanded by producing hybrid nanocomposites with polymers that provide additional functions, responsiveness, and improved biocompatibility. Polymers may deliver large quantities of drugs or genes in therapeutic applications. A polymer alters the surface charges of AuNPs to improve or modulate cellular uptake efficiency and their biodistribution in the body. Furthermore, designing the functionality of nanocomposites to respond to an endo- or exogenous stimulus, such as pH, enzymes, or light, may facilitate the development of novel therapeutic applications. In this review, we focus on the recent progress in the use of AuNPs and Au-polymer nanocomposites in therapeutic applications such as drug or gene delivery, photothermal therapy, and tissue engineering.

Gold nanorod@void@polypyrrole yolk@shell nanostructures: Synchronous regulation of photothermal and drug delivery performance for synergistic cancer therapy

Synergistic therapy has been emerging as new trend for effective tumor treatment due to synchronous function and cooperative reinforcement of multi therapeutic modalities. Herein, gold nanorods (GNRs) encapsulated into polypyrrole (PPy) shell with tunable void space (GNRs@Void@PPy) showing yolk@shell nanostructures were innovatively designed. The exploitation of dual near-infrared (NIR) absorptive species offered synergistic enhancement of photothermal performance. In addition, the manipulation of the void space between them provided additional benefits of high drug encapsulation efficiency (92.6%) and, interestingly, tumor microenvironment and NIR irradiation triggered targeted drug releasing. Moreover, the GNRs@Void@PPy exhibited excellent biocompatibility, and optimal curative effect by chemo-photothermal synergistic therapy was achieved through both in vitro and in vivo antitumor activity investigation.

Gold Nanorods: The Most Versatile Plasmonic Nanoparticles

Gold nanorods (NRs), pseudo-one-dimensional rod-shaped nanoparticles (NPs), have become one of the burgeoning materials in the recent years due to their anisotropic shape and adjustable plasmonic properties. With the continuous improvement in synthetic methods, a variety of materials have been attached around Au NRs to achieve unexpected or improved plasmonic properties and explore state-of-the-art technologies. In this review, we comprehensively summarize the latest progress on Au NRs, the most versatile anisotropic plasmonic NPs. We present a representative overview of the advances in the synthetic strategies and outline an extensive catalogue of Au-NR-based heterostructures with tailored architectures and special functionalities. The bottom-up assembly of Au NRs into preprogrammed metastructures is then discussed, as well as the design principles. We also provide a systematic elucidation of the different plasmonic properties associated with the Au-NR-based structures, followed by a discussion of the promising applications of Au NRs in various fields. We finally discuss the future research directions and challenges of Au NRs.

In situ hydrogen nanogenerator for bimodal imaging guided synergistic photothermal/hydrogen therapies

Multifunctional nanoagents integrating multiple therapeutic and imaging functions hold promise in the field of non-invasive and precise tumor therapies. However, the complex preparation process and uncertain drug metabolism of nanoagents loaded with various therapeutic agents or imaging agents greatly hinder its clinical applications. Developing simple and effective nanoagents that integrate multiple therapeutic and imaging functions remain a huge challenge. Therefore, a novel strategy based on in situ hydrogen release is proposed in this work: aminoborane (AB) was loaded onto mesoporous polydopamine nanoparticles (MPDA NPs) as a prodrug for hydrogen production, and then, PEG was modified on the surface of nanoparticles (represented as AB@MPDA-PEG). MPDA NPs not only act as photothermal agents (PTA) with high photothermal conversion efficiency (808 nm, η = 38.72%) but also as the carriers of AB accumulated in the tumor through enhanced permeability and retention (EPR) effect. H₂ gas generated by AB in the weak acid conditions of the tumor microenvironment (TME) not only was used to treat tumors via a combination of hydrogen and photothermal therapies but also serves as a US and CT contrast agent, providing accurate guidance for tumor treatment. Finally, in vivo and in vitro investigation suggest that the designed multifunctional nanosystem not only showed excellent properties such as high hydrogen-loading capacity, long-lasting sustained hydrogen release ability and excellent biocompatibility but also achieve selective PTT/hydrogen therapies and US/CT bimodal imaging functions, which can effectively guide antitumor therapies. The proposed hydrogen gas-based strategy for combination therapies and bimodal imaging integration holds promise as an efficient and safe tumor treatment for future clinical translation.

Nano-Carriers of Combination Tumor Physical Stimuli-Responsive Therapies

With the development of nanotechnology, Tumor Physical Stimuli-Responsive Therapies (TPSRTs) have reached a new stage because of the remarkable characteristics of nanocarriers. The nanocarriers enable such therapies to overcome the drawbacks of traditional therapies, such as radiotherapy or chemotherapy. To further explore the possibility of the nanocarrier-assisted TPSRTs, scientists have combined different TPSRTs via; the platform of nanocarriers into combination TPSRTs, which include Photothermal Therapy (PTT) with Magnetic Hyperthermia Therapy (MHT), PTT with Sonodynamic Therapy (SDT), MHT with Photodynamic Therapy (PDT), and PDT with PTT. To achieve such therapies, it requires to fully utilize the versatile functions of a specific nanocarrier, which depend on a pellucid understanding of the traits of those nanocarriers. This review covers the principles of different TPSRTs and their combinations, summarizes various types of combination TPSRTs nanocarriers and their therapeutic effects on tumors, and discusses the current disadvantages and future developments of these nanocarriers in the application of combination TPSRTs.

A mesoporous polydopamine nanoparticle enables highly efficient manganese encapsulation for enhanced MRI-guided photothermal therapy

Theranostic agents based on magnetic resonance imaging (MRI) and photothermal therapy (PTT) play an important role in tumor therapy. However, the available theranostic agents are facing great challenges such as biocompatibility, MRI contrast effect and photothermal conversion efficiency (η). In this work, mesoporous polydopamine nanoparticles (MPDAPs/Mn) were prepared on MRI and PTT combined theranostic nanoplatforms, of which the high loading manganese ions and specific surface areas enable good MRI contrast and excellent photothermal conversion efficiency, respectively. The MPDAPs/Mn have uniform morphology, good stability and biocompatibility. Meanwhile, in vitro and in vivo studies have confirmed their superior T₁-weighted MRI effect and photothermal conversion efficiency. Furthermore, MPDAPs/Mn have excellent antitumor efficacy in HeLa tumor-bearing mice. Therefore, this developed MPDAPs/Mn theranostic nanoplatform could be a promising candidate for MRI-guided photothermal cancer therapy.

Hybrid Nanosystems for Biomedical Applications

Inorganic/organic hybrid nanosystems have been increasingly developed for their versatility and efficacy at overcoming obstacles not readily surmounted by nonhybridized counterparts. Currently, hybrid nanosystems are implemented for gene therapy, drug delivery, and phototherapy in addition to tissue regeneration, vaccines, antibacterials, biomolecule detection, imaging probes, and theranostics. Though diverse, these nanosystems can be classified according to foundational inorganic/organic components, accessory moieties, and architecture of hybridization. Within this Review, we begin by providing a historical context for the development of biomedical hybrid nanosystems before describing the properties, synthesis, and characterization of their component building blocks. Afterward, we introduce the architectures of hybridization and highlight recent biomedical nanosystem developments by area of application, emphasizing hybrids of distinctive utility and innovation. Finally, we draw attention to ongoing clinical trials before recapping our discussion of hybrid nanosystems and providing a perspective on the future of the field.

Melt Electrospinning of Polymers: Blends, Nanocomposites, Additives and Applications

Melt electrospinning has been developed in the last decade as an eco-friendly and solvent-free process to fill the gap between the advantages of solution electrospinning and the need of a cost-effective technique for industrial applications. Although the benefits of using melt electrospinning compared to solution electrospinning are impressive, there are still challenges that should be solved. These mainly concern to the improvement of polymer melt processability with reduction of polymer degradation and enhancement of fiber stability; and the achievement of a good control over the fiber size and especially for the production of large scale ultrafine fibers. This review is focused in the last research works discussing the different melt processing techniques, the most significant melt processing parameters, the incorporation of different additives (e.g., viscosity and conductivity modifiers), the development of polymer blends and nanocomposites, the new potential applications and the use of drug-loaded melt electrospun scaffolds for biomedical applications.

Bistratal Au@Bi2S3 nanobones for excellent NIR-triggered/multimodal imaging-guided synergistic therapy for liver cancer

To fabricate a highly biocompatible nanoplatform enabling synergistic therapy and real-time imaging, novel Au@Bi2S3 core shell nanobones (NBs) (Au@Bi2S3 NBs) with Au nanorods as cores were synthesized. The combination of Au nanorods with Bi2S3 film made the Au@Bi2S3 NBs exhibit ultrahigh photothermal (PT) conversion efficiency, remarkable photoacoustic (PA) imaging and high computed tomography (CT) performance; these Au@Bi2S3 NBs thus are a promising nanotheranostic agent for PT/PA/CT imaging. Subsequently, poly(N-vinylpyrrolidone)-modified Au@Bi2S3 NBs (Au@Bi2S3-PVP NBs) were successfully loaded with the anticancer drug doxorubicin (DOX), and a satisfactory pH sensitive release profile was achieved, thus revealing the great potential of Au@Bi2S3-PVP NBs in chemotherapy as a drug carrier to deliver DOX into cancer cells. Both in vitro and in vivo investigations demonstrated that the Au@Bi2S3-PVP NBs possessed multiple desired features for cancer therapy, including extremely low toxicity, good biocompatibility, high drug loading ability, precise tumor targeting and effective accumulation. Highly efficient ablation of the human liver cancer cell HepG2 was achieved through Au@Bi2S3-PVP NB-mediated photothermal therapy (PTT). As both a contrast enhancement probe and therapeutic agent, Au@Bi2S3-PVP NBs provided outstanding NIR-triggered multi-modal PT/PA/CT imaging-guided PTT and effectively inhibited the growth of HepG2 liver cancer cells via synergistic chemo/PT therapy.

Nucleation Points: The Forgotten Parameter in the Synthesis of Hydrogel-Coated Gold Nanoparticles

The implementation of gold-hydrogel core-shell nanomaterials in novel light-driven technologies requires the development of well-controlled and scalable synthesis protocols with precisely tunable properties. Herein, new insights are presented concerning the importance of using the concentration of gold cores as a control parameter in the seeded precipitation polymerization process to modulate—regardless of core size—relevant fabrication parameters such as encapsulation yield, particle size and shrinkage capacity. Controlling the number of nucleation points results in the facile tuning of the encapsulation process, with yields reaching 99% of gold cores even when using different core sizes at a given particle concentration. This demonstration is extended to the encapsulation of bimodal gold core mixtures with equally precise control on the encapsulation yield, suggesting that this principle could be extended to encapsulating cores composed of other materials. These findings could have a significant impact on the development of stimuli-responsive smart materials.

Solvent Quality-Mediated Regioselective Modification of Gold Nanorods with Thiol-Terminated Polymers

Modification of nanorods (NRs) with functional polymer ligands is of great significance to enhance their surface chemistry and prompt their applications in many fields (e.g., photothermal therapy, bioimaging, and catalysis). However, the regioselective modification of AuNRs still remains a great challenge. Herein, we introduce a facile yet versatile strategy to achieve the regioselective modification of AuNRs through a solvent quality-mediated strategy. By employing a poor solvent of the original ligand cetyltrimethylammonium bromide (CTAB) as the medium in the modification, polymer ligands would selectively graft onto the two ends of AuNRs, while polymer ligands would graft onto the entire surface when employing a good solvent. This strategy demonstrates good reproducibility and is applicable to both hydrophilic and hydrophobic polymer ligand modifications. Moreover, by combing our strategy with the preoccupation route, the two ends and sidewall of AuNRs modified by two different polymers form an "ABA"-type building block, which can further self-assemble into well-ordered superstructures. Our finding provides a new opportunity for multifunctionalization of NRs.

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.

Stem Cell-Based Delivery of Gold/Chlorin e6 Nanocomplexes for Combined Photothermal and Photodynamic Therapy

Combining photothermal and photodynamic modalities has shown encouraging therapeutic efficacy against various malignant cancers. Developing a delivery method for targeting and penetrating tumors is still a major focus for advancing this therapeutic approach. Herein, we report a novel strategy involving the utilization of stem cells as a live carrier to codeliver photothermal and photodynamic agents for cancer therapy. To this end, a novel gold nanorod (AuNR)-PEG-PEI (APP)/chlorin e6 (Ce6)-loaded adipose-derived stem cell (ADSC) system is proposed in which AuNRs and Ce6 act as the photothermal and photodynamic agents, respectively. To integrate with stem cells, the APP/Ce6 nanocomplexes exhibit advantages of low drug leakage, low cytotoxicity, efficient cellular uptake, and redox-responsive release. After loading of APP/Ce6 nanocomplexes, the ADSCs still maintained good tumor tropism and were capable of penetrating into the tumor spheroids. The photothermal effect induced by exposure to near-infrared light irradiation at 808 nm promoted the release of Ce6 from the stem cells into the surroundings and hence increased its availability to treat cancer cells. APP/Ce6-loaded ADSCs exerted effective dose-dependent in vitro anticancer activities via anticipated photothermal and photodynamic effects. In a murine CT26 colon cancer model, APP/Ce6 delivered by ADSCs resulted in superior tumor suppression compared to other delivery strategies. It was also noted that in vivo applications of APP/Ce6-loaded ADSCs did not induce noticeable detrimental effects on normal tissues/organs.

Multilayer capsules encapsulating nimbin and doxorubicin for cancer chemo-photothermal therapy

Layer-by-layer (LbL) assembled poly(allylamine hydrochloride) (PAH) and poly(methacrylic acid) (PMA) microcapsules were designed to incorporate gold nanorods (NRs) and co-encapsulate and release two drugs for cancer therapy. Calcium carbonate (CaCO₃) microparticles modified with preformed NRs were used as sacrificial templates for the fabrication of hollow PAH/PMA/NR capsules incorporated with NRs. The hollow capsules were found to be 4.5 ± 0.5 µm in size and appeared with uniformly distributed NRs in the interior of the capsules. The morphology of the capsules transformed from pore free continuous structure to porous structure under laser light irradiation at 808 nm and 0.5 W cm^-2. The encapsulation experiments showed that the hydrophilic drug (doxorubicin hydrochloride, Dox) was encapsulated in the interior of the capsules while the hydrophobic drug (nimbin, NB) was entrapped in the porous polymeric network of the layer components. The encapsulation efficiency was found to be 30% for both Dox and NB. The release experiments showed an initial burst release followed by sustained release up to 3 h. Notably, the release was completed within 30 min under NIR irradiation at 808 nm. The estimated IC₅₀ values against THP-1 cells were 75 and 1.8 µM for NB and Dox, respectively. The dual drug loaded capsules showed excellent anticancer activity against THP-1 cells under NIR light exposure in in-vitro experiments. Thus, such remotely addressable dual-drug loaded capsules with the provision for encapsulation of natural drugs demonstrate high potential for use as theranostics in cancer therapy.

Biocompatible chitosan-carbon nanocage hybrids for sustained drug release and highly efficient laser and microwave co-irradiation induced cancer therapy

Graphitic carbon nanocages (GCNCs) are unique graphene-based nanomaterials that can be used for cancer photothermal therapy (PTT). However, low toxicity GCNC-based organic/inorganic hybrid biomaterials for microwave irradiation assisted PTT have not yet been reported. In the present study, chitosan (CS)-coated GCNCs (CS-GCNCs) loaded with 5-fluorouracil (5Fu) were used for cancer therapy when activated by 808-nm laser and microwave co-irradiation. The cytotoxicity of GCNCs was significantly reduced after coating with CS. For example, fewer cell-cycle defects were caused by CS-GCNCs in comparison with non-coated GCNCs. The release rate of 5Fu from CS-GCNCs was significantly slower than that of 5Fu from GCNCs, providing sustained release. The release rate could be accelerated by 808-nm laser and microwave co-irradiation. The 5Fu in CS-GCNCs retained high cancer cell killing bioactivity by enhancing the caspase-3 expression level. The cancer cell killing and tumor inhibition efficiencies of the 5Fu-loaded nanomaterials increased significantly under 808-nm laser and microwave co-irradiation. The strong cell killing and tumor ablation activities were due to the synergy of the enhanced GCNC thermal effect caused by laser and microwave co-irradiation and the chemotherapy of 5Fu. Our research opens a door for the development of drug-loaded GCNC-based nano-biomaterials for chemo-photothermal synergistic therapy with the assistance of microwave irradiation. STATEMENT OF SIGNIFICANCE: Graphitic carbon nanocages (GCNCs) are graphene-based nanomaterials that can be used for both drug loading and cancer photothermal therapy (PTT). Herein, we showed that chitosan (CS)-GCNCs hybrid biomaterials had very low cytotoxicity, high ability for loading drug, and exhibited sustained drug release. In particular, although low-power microwaves alone are unable to trigger cancer cell damage by GCNCs, the cell killing and mouse tumor inhibition efficiencies were significantly improved by near-infrared (NIR) laser and microwave co-irradiation compared with laser-triggered PTT alone. This combined use of laser and microwave co-irradiation promises essential therapeutic modality and opens a new avenue for PTT.

WS2 nanosheets functionalized by biomimetic lipids with enhanced dispersibility for photothermal and chemo combination therapy

A WS₂-lipid nanocarrier with enhanced stability and intratumoral accumulation was synthesized for photothermal-chemo combination therapy

Mesoporous Polydopamine Carrying Manganese Carbonyl Responds to Tumor Microenvironment for Multimodal Imaging‐Guided Cancer Therapy

Multifunctional nanodrugs integrating multiple therapeutic and imaging functions may find tremendous biomedical applications. However, the development of a simple yet potent theranostic nanosystem with a high payload and microenvironment responsiveness enhancing imaging‐guided cancer therapy is still a great challenge. Herein, a kind of MnCO‐entrapped mesoporous polydopamine nanoparticles are developed, which reach a 1.5 mg payload per gram carrier and exhibit marked theranostic capability through effective CO/Mn2+ generation and photothermal conversion inside the H+ and H2O2‐enriched tumor microenvironment, for a magnetic resonance/photoacoustic bimodal imaging‐guided tumor therapy. The multifunctional nanosystem exhibits a biocompatibility highly desirable for in vivo application and superior performance in inhibiting tumor growth and recurrence via combination CO and photothermal therapy.

Reusable Hollow Polymer Microreactors Incorporated with Anisotropic Nanoparticles for Catalysis Application

We report a methodology to encapsulate gold nanorods (AuNRs) and gold bipyramids (AuBPs) into polyelectrolyte capsules for catalytic application. Microreactors (capsules with encapsulated NRs or BPs) were fabricated by sequential deposition of poly(allylamine hydrochloride) and dextran sulfate on modified sacrificial template, followed by core dissolution. AuNRs and AuBPs of size 25-30 nm were successfully encapsulated in the fabricated polyelectrolyte capsules and were stable and distributed uniformly in the interior. Fabricated microreactors were investigated as catalysts for the reduction of p-nitrophenol to p-aminophenol in the presence of sodium borohydride in aqueous phase. Reaction parameters such as order, conversion, and rate constants were estimated for microreactors and compared to free anisotropic nanoparticles in suspension. The reaction rate was higher for NRs in both free and capsule forms compared to BPs. Microreactors demonstrated excellent catalytic activity even after three times of use. Such capsules have high potential for use as microreactors in applications such as catalysis, drug delivery, imaging, and cancer chemo-photothermal therapy.

Gold Nanorods/Polypyrrole/m-SiO2 Core/Shell Hybrids as Drug Nanocarriers for Efficient Chemo-Photothermal Therapy

Combination therapy as a novel strategy with the combination of photothermal therapy and chemotherapy (photothermal-chemotherapy) has aroused the tremendously increasing interest owing to the synergistic therapeutic effect on destroying cancer cells because the hyperthermia generated from photothermal therapy can promote drug delivery into tumors, which would highly increase therapeutic efficacy as compared to those sole treatments. Herein, we fabricated a novel nanomaterial-based carrier composed of gold nanorods (GNRs), polypyrrole (PPy), and mesoporous silica to form GNRs/PPy/m-SiO₂ core/shell hybrids. After loading the anticancer drug of doxorubicin (DOX), the photothermal effect and the drug-release behavior of GNRs/PPy@m-SiO₂-DOX hybrids were investigated. The in vitro and in vivo near-infrared (NIR) photothermal-chemotherapy were also revealed. The results indicated that the NIR-induced photothermal effect was beneficial to promote the release of the drug. In addition, combination therapy demonstrated the enhanced synergistic efficacy and excellent treatment efficacy for cancer therapy.

Studies on effectiveness of PTT on 3D tumor model under microfluidic conditions using aptamer-modified nanoshells

Herein, we present the research focused on the synthesis and application of aptamer-modified gold nanoshells for photothermal therapy (PTT). NIR-absorbing hollow gold nanoshells were synthetized and conjugated with anti-MUC1 aptamer (HGNs@anti-MUC1). MUC1 (Mucin 1) is a transmembrane glycoprotein, which is overexpressed in a variety of epithelial cancers (eg. breast, lung, pancreatic). In order to evaluate the efficiency of PTT with HGNs@anti-MUC1 we used 3D cell culture model - multicellular spheroids. The selected cell culture model is considered as the best in vitro model for cancer research (similar morphology, metabolite and oxygen gradients, cellular interactions and cell growth kinetics in the spheroids are similar to the early stage of a nonvascular tumor). We conducted our research on human normal (MRC-5, MCF-10A) and tumor (A549, MCF-7) cell lines using a microfluidic system. Aptamer-modified nanoparticles were accumulated selectively in tumor cells (A549, MCF-7) and this fact contributed to the reduction of tumor spheroids viability and size. It should be underlined, that it is the first example of photothermal therapy carried out in a microsystem on multicellular spheroids.