Composite photothermal platform of polypyrrole-enveloped Fe₃O₄ nanoparticle self-assembled superstructures

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.

Nanomaterial-Enabled Photothermal Heating and Its Use for Cancer Therapy via Localized Hyperthermia

Photothermal therapy (PTT), which employs nanoscale transducers delivered into a tumor to locally generate heat upon irradiation with near-infrared light, shows great potential in killing cancer cells through hyperthermia. The efficacy of such a treatment is determined by a number of factors, including the amount, distribution, and dissipation of the generated heat, as well as the type of cancer cell involved. The amount of heat generated is largely controlled by the number of transducers accumulated inside the tumor, the absorption coefficient and photothermal conversion efficiency of the transducer, and the irradiance of the light. The efficacy of treatment depends on the distribution of the transducers in the tumor and the penetration depth of the light. The vascularity and tissue thermal conduction both affect the dissipation of heat and thereby the distribution of temperature. The successful implementation of PTT in the clinic setting critically depends on techniques for real-time monitoring and management of temperature.

Biocompatible Ferrofluid-Based Millirobot for Tumor Photothermal Therapy in Near-Infrared-II Window

Ferrofluidic robots with excellent deformability and controllability have been intensively studied recently. However, most of these studies are in vitro and the use of ferrofluids for in vivo medicinal applications remains a big challenge. The application of ferrofluidic robots to the body requires the solution of many key problems. In this study, biocompatibility, controllability, and tumor-killing efficacy are considered when creating a ferrofluid-based millirobot for in vivo tumor-targeted therapy. For biocompatibility problems, corn oil is used specifically for the ferrofluid robot. In addition, a control system is built that enables a 3D magnetic drive to be implemented in complex biological media. Using the photothermal conversion property of 1064 nm, the ferrofluid robot can kill tumor cells in vitro; inhibit tumor volume, destroy the tumor interstitium, increase tumor cell apoptosis, and inhibit tumor cell proliferation in vivo. This study provides a reference for ferrofluid-based millirobots to achieve targeted therapies in vivo.

Engineering Platelet Membrane Imitating Nanoparticles for Targeted Therapeutic Delivery

Platelet Membrane Imitating Nanoparticles (PMINs) is a novel drug delivery system that imitates the structure and functionality of platelet membranes. PMINs imitate surface markers of platelets to target specific cells and transport therapeutic cargo. PMINs are engineered by incorporating the drug into the platelet membrane and encapsulating it in a nanoparticle scaffold. This allows PMINs to circulate in the bloodstream and bind to target cells with high specificity, reducing off-target effects and improving therapeutic efficacy. The engineering of PMINs entails several stages, including the separation and purification of platelet membranes, the integration of therapeutic cargo into the membrane, and the encapsulation of the membrane in a nanoparticle scaffold. In addition to being involved in a few pathological conditions including cancer, atherosclerosis, and rheumatoid arthritis, platelets are crucial to the body's physiological processes. This study includes the preparation and characterization of platelet membrane-like nanoparticles and focuses on their most recent advancements in targeted therapy for conditions, including cancer, immunological disorders, atherosclerosis, phototherapy, etc. PMINs are a potential drug delivery system that combines the advantages of platelet membranes with nanoparticles. The capacity to create PMMNs with particular therapeutic cargo and surface markers provides new possibilities for targeted medication administration and might completely change the way that medicine is practiced. Despite the need for more studies to optimize the engineering process and evaluate the effectiveness and safety of PMINs in clinical trials, this technology has a lot of potential.

High-Strength Magnetic Hydrogels with Photoweldability Made by Stepwise Assembly of Magnetic-Nanoparticle-Integrated Aramid Nanofiber Composites

Hydrogels capable of transforming in response to a magnetic field hold great promise for applications in soft actuators and biomedical robots. However, achieving high mechanical strength and good manufacturability in magnetic hydrogels remains challenging. Here, inspired by natural load-bearing soft tissues, a class of composite magnetic hydrogels is developed with tissue-mimetic mechanical properties and photothermal welding/healing capability. In these hydrogels, a hybrid network involving aramid nanofibers, Fe₃O₄ nanoparticles, and poly(vinyl alcohol) is accomplished by a stepwise assembly of the functional components. The engineered interactions between nanoscale constituents enable facile materials processing and confer a combination of excellent mechanical properties, magnetism, water content, and porosity. Furthermore, the photothermal property of Fe₃O₄ nanoparticles organized around the nanofiber network allows near-infrared welding of the hydrogels, providing a versatile means to fabricate heterogeneous structures with custom designs. Complex modes of magnetic actuation are made possible with the manufactured heterogeneous hydrogel structures, suggesting opportunities for further applications in implantable soft robots, drug delivery systems, human-machine interactions, and other technologies.

A Multifunctional, Highly Biocompatible, and Double-Triggering Caramelized Nanotheranostic System Loaded with Fe3O4 and DOX for Combined Chemo-Photothermal Therapy and Real-Time Magnetic Resonance Imaging Monitoring of Triple Negative Breast Cancer

Purpose

Owing to lack of specific molecular targets, the current clinical therapeutic strategy for triple negative breast cancer (TNBC) is still limited. In recent years, some nanosystems for malignancy treatment have received considerable attention. In this study, we prepared caramelized nanospheres (CNSs) loaded with doxorubicin (DOX) and Fe₃O₄ to achieve the synergistic effect of combined therapy and real-time magnetic resonance imaging (MRI) monitoring, so as to improve the diagnosis and therapeutic effect of TNBC.

Methods

CNSs with biocompatibility and unique optical properties were prepared by hydrothermal method, DOX and Fe₃O₄ were loaded on it to obtain Fe₃O₄/DOX@CNSs nanosystem. Characteristics including morphology, hydrodynamic size, zeta potentials and magnetic properties of Fe₃O₄/DOX@CNSs were evaluated. The DOX release was evaluated by different pH/near-infrared (NIR) light energy. Biosafety, pharmacokinetics, MRI and therapeutic treatment of Fe₃O₄@CNSs, DOX and Fe₃O₄/DOX@CNSs were examined in vitro or in vivo.

Results

Fe₃O₄/DOX@CNSs has an average particle size of 160 nm and a zeta potential of 27.5mV, it demonstrated that Fe₃O₄/DOX@CNSs is a stable and homogeneous dispersed system. The hemolysis experiment of Fe₃O₄/DOX@CNSs proved that it can be used in vivo. Fe₃O₄/DOX@CNSs displayed high photothermal conversion efficiency, extensive pH/heat-induced DOX release. 70.3% DOX release is observed under the 808 nm laser in the pH = 5 PBS solution, obviously higher than pH = 5 (50.9%) and pH = 7.4 (less than 10%). Pharmacokinetic experiments indicated the t1/2β, and AUC_0-t of Fe₃O₄/DOX@CNSs were 1.96 and 1.31 -fold higher than those of DOX solution, respectively. Additionally, Fe₃O₄/DOX@CNSs with NIR had the greatest tumor suppression in vitro and in vivo. Moreover, this nanosystem demonstrated distinct contrast enhancement on T2 MRI to achieve real-time imaging monitoring during treatment.

Conclusion

Fe₃O₄/DOX@CNSs is a highly biocompatible, double-triggering and improved DOX bioavailability nanosystem that combines chemo-PTT and real-time MRI monitoring to achieve integration of diagnosis and treatment of TNBC.

Iron-rich coal fly ash-polydopamine-silver nanocomposite (IRCFA-PDA-Ag NPs): tailored material for remediation of methylene blue dye from aqueous solution

Water pollution has become one of the most acute environmental problems. One of the pollutants coming to water bodies from industries are dyes, which are harmful to human health, living organisms, and the esthetic appearance of water. Most dyes are toxic, carcinogenic, rarely biodegradable, and highly soluble in water. Therefore, industrial wastewater treatment has become important. Adsorption technique of removal of dyes from water is simple, efficient, and inexpensive as compared to other techniques. Adsorption efficiency depends on the type and surface area of adsorbents. Iron-rich coal fly ash (IRCFA)-Polydopamine (PDA)@ Silver (Ag) nanocomposite was prepared by separating the iron-rich part (IRCFA) from coal fly ash and coated with polydopamine. IRCFA was mixed with 10 mM tris buffer solution containing 1 g dopamine. The prepared IRCFA-PDA was added to an aqueous solution of silver nitrate, heated at 60 °C, and then 30 mL of flower waste extract was added to this solution. Solid IRCFA-PDA@Ag was obtained, and the prepared nanocomposite was used for the removal of methylene blue (MB) dye from water. The nanocomposite used was prepared by a cost-effective method and has high reusability, separability, and fast regeneration ability. The mechanism of removal of MB dye has been discussed in detail.

Simultaneous Enhancement of Magnetothermal and Photothermal Responses by Zn, Co Co-Doped Ferrite Nanoparticles

Reducing nanoparticle (NP) dosage for hyperthermia therapy has remained a great challenge. In this work, efficiencies of alternating current (AC) magnetic field and near-infrared (NIR) heating are simultaneously enhanced by Zn and Co co-doping of magnetite NPs. The optimum magnetic anisotropy for maximized loss power under each magnetic field is achieved by tuning the doping concentration. The specific loss power of Zn_0.3 Co_0.08 Fe_2.62 O₄ @SiO₂ NPs reaches 2428 W g^-1 under an AC field of 27 kA m^-1 at 430 kHz; 12 296 W g^-1 under NIR laser irradiation at 808 nm and 2.5 W cm^-2 ; and an unprecedented value of 14 724 W g^-1 under dual mode. These values far exceed what has been achieved previously in iron oxide NPs. Ex vivo experiments on sacrificial mice show that while the NP dosage is substantially reduced to that used for magnetic resonance imaging, the surface body temperature of the mice reaches 50 °C after exposure to both AC field and laser irradiation under field parameters and laser intensity below safety limits. This nanoplatform is thus promising for multi-modal local hyperthermia therapy.

In vivo photoacoustic image-guided tumor photothermal therapy and real-time temperature monitoring using a core-shell polypyrrole@CuS nanohybrid

Near-infrared (NIR) laser triggered theranostic platforms are increasingly used in clinical nanomedicine applications. In this work, a core-shell composite consisting of polypyrrole (PPy) coated copper sulfide (CuS) nanospheres with high photothermal efficiency and good photostability has been fabricated via a facile interfacial polymerization. The PPy@CuS nanohybrid had a hydrodynamic diameter of 58.5 nm with a CuS core and PPy shell and exhibited strong optical absorption and photon-to-heat conversion in the NIR region, leading to a sufficient photohyperthermic effect under irradiation with a 808 nm continuous wave laser. In vivo studies showed that the Ppy@CuS nanohybrids produced significant photoacoustic signals and exhibited remarkable photothermal therapeutic efficacy. Furthermore, the core-shell composites exhibited improved temperature elevation and photostability. The temperature-induced changes can be detected and monitored using photoacoustic imaging, thus allowing the control of the thermal dose while minimizing photothermal damage to surrounding healthy tissues. In summary, this study demonstrates that this novel platform could potentially be used for photoacoustic image-guided photothermal therapy and real-time temperature monitoring in cancer theranostics.

Tumor acidity-activatable photothermal/Fenton nanoagent for synergistic therapy

Intracellular formation of therapeutic agents has become one of the effective ways for cancer-specific treatment. Herein, a tumor acidity-activatable photothermal/Fenton nanoagent (denoted as CoPy) was constructed based on oxidized zeolitic imidazolate framework-67 (oxZIF-67) nanosheet and pyrrole (Py) monomer for synergistic therapy. The CoPy showed negligible toxicity to normal cell models RAW264.7 and 3T3 cell lines, and could be degraded by ascorbic acid in normal physiological conditions. However, once uptaken by 4T1 cells, the acidic pH led to the release of Co³⁺, which served as a strong oxidant to induce the polymerization of Py to form polypyrrole (PPy) for site-specific photothermal therapy (PTT). Most appealingly, the PPy could chelate the generated Co²⁺ in the polymerization process to initiate the Fenton-like reaction, which was more capable to produce highly toxic hydroxyl radical (•OH) for chemodynamic therapy (CDT) compared to the free Co²⁺ ones. In vitro and in vivo experiments demonstrated that all functionalities on CoPy worked collaboratively, and 78% of tumors were inhibited through cooperative PTT/CDT. Such a novel therapeutic nanoagent with tumor selectivity opens new opportunities for combinational treatment paradigms.

Preparation and synergistic chemo-photothermal therapy of redox-responsive carboxymethyl cellulose/chitosan complex nanoparticles

Chemo-photothermal combination therapy has great promise for enhanced tumor treatment. Hereby, we developed a complex nanoparticle using electrostatic absorption method, in which the inner chitosan (CS) NPs loaded polypyrrole (PPy) nanoparticles and 5-fluorouracil (5Fu), the outer shell was carboxymethyl cellulose (CMC) crosslinked with disulfide. The drug loaded polysaccharide complex nanoparticles displayed good photothermal effects, and the drug release would be triggered by multi-model response of NIR irradiation, high glutathione (GSH) and weak acidity in tumor environment. In vitro biological studies indicated the nanopartiles could be effectively internalized by HepG2 cancer cells. Moreover, the remarkable inhibition of the CMC complex PPy and 5Fu loaded CS nanoparticles (CMC/CS@PPy + 5Fu NPs) against tumor growth was achieved in HepG2-bearing mice model, suggesting its great potential for synergetic chemo-photothermal therapy.

Advances in photothermal nanomaterials for biomedical, environmental and energy applications

Materials that exhibit photothermal effect have attracted enormous research interests due to their ability to strongly absorb light and effectively transform it into heat for a wide range of applications in biomedical, environmental and energy related fields. The past decade has witnessed significant advances in the preparation of a variety of photothermal materials, mainly due to the emergence of many nano-enabled new materials, such as plasmonic metals, stoichiometric/non-stoichiometric semiconductors, and the newly emerging MXenes. These photothermal nanomaterials can be hybridized with other constituents to form functional hybrids or composites for achieving enhanced photothermal performance. In this review, we present the fundamental insight of inorganic photothermal materials, including their photothermal conversion mechanisms/properties as well as their potential applications in various fields. Emphasis is placed on strategic approaches for improving their light harvesting and photothermal conversion capabilities through engineering their nanostructured size, shape, composition, bandgap and so on. Lastly, the underlying challenges and perspectives for future development of photothermal nanomaterials are proposed.

Condensed Clustered Iron Oxides for Ultrahigh Photothermal Conversion and In Vivo Multimodal Imaging

Magnetic iron oxide nanocrystals (MIONs) are established as potent theranostic nanoplatforms due to their biocompatibility and the multifunctionality of their spin-active atomic framework. Recent insights have also unveiled their attractive near-infrared photothermal properties, which are, however, limited by their low near-infrared absorbance, resulting in noncompetitive photothermal conversion efficiencies (PCEs). Herein, we report on the dramatically improved photothermal conversion of condensed clustered MIONs, reaching an ultrahigh PCE of 71% at 808 nm, surpassing the so-far MION-based photothermal agents and even benchmark near-infrared photothermal nanomaterials. Moreover, their surface passivation is achieved through a simple self-assembly process, securing high colloidal stability and structural integrity in complex biological media. The bifunctional polymeric canopy simultaneously provided binding sites for anchoring additional cargo, such as a strong near-infrared-absorbing and fluorescent dye, enabling in vivo optical and photoacoustic imaging in deep tissues, while the iron oxide core ensures detection by magnetic resonance imaging. In vitro studies also highlighted a synergy-amplified photothermal effect that significantly reduces the viability of A549 cancer cells upon 808 nm laser irradiation. Integration of such-previously elusive-photophysical properties with simple and cost-effective nanoengineering through self-assembly represents a significant step toward sophisticated nanotheranostics, with great potential in the field of nanomedicine.

Dual-Targeting Glycol Chitosan/Heparin-Decorated Polypyrrole Nanoparticle for Augmented Photothermal Thrombolytic Therapy

Near-infrared (NIR)-light-modulated photothermal thrombolysis has been investigated to overcome the hemorrhage danger posed by clinical clot-busting substances. A long-standing issue in thrombosis fibrinolytics is the lack of lesion-specific therapy, which should not be ignored. Herein, a novel thrombolysis therapy using photothermal disintegration of a fibrin clot was explored through dual-targeting glycol chitosan/heparin-decorated polypyrrole nanoparticles (GCS-PPY-H NPs) to enhance thrombus delivery and thrombolytic therapeutic efficacy. GCS-PPY-H NPs can target acidic/P-selectin high-expression inflammatory endothelial cells/thrombus sites for initiating lesion-site-specific thrombolysis by hyperthermia using NIR irradiation. A significant fibrin clot-clearance rate was achieved with thrombolysis using dual-targeting/modality photothermal clot disintegration in vivo. The molecular level mechanisms of the developed nanoformulations and interface properties were determined using multiple surface specific analytical techniques, such as particle size distribution, zeta potential, electron microscopy, Fourier-transform infrared spectroscopy (FTIR), wavelength absorbance, photothermal, immunofluorescence, and histology. Owing to the augmented thrombus delivery of GCS-PPY-H NPs and swift treatment time, dual-targeting photothermal clot disintegration as a systematic treatment using GCS-PPY-H NPs can be effectively applied in thrombolysis. This novel approach possesses a promising future for thrombolytic treatment.

Superparamagnetic Nanoparticles with Efficient Near-Infrared Photothermal Effect at the Second Biological Window

Superparamagnetic nanoparticles (iron oxide nanoparticles-IONs) are suitable for hyperthermia after irradiating with radiofrequency radiation. Concerning the suitability for laser ablation, IONs present a low molar absorption coefficient in the near-infrared region close to 800 nm. For this reason, they are combined with other photothermal agents into a hybrid composite. Here, we show that IONs absorb and convert into heat the infrared radiation characteristic of the so-called second-biological window (1000-1350 nm) and, in consequence, they can be used for thermal ablation in such wavelengths. To the known excellent water solubility, colloidal stability and biocompatibility exhibited by IONs, an outstanding photothermal performance must be added. For instance, a temperature increase of 36 °C was obtained after irradiating at 8.7 W cm^-2 for 10 min a suspension of IONs at iron concentration of 255 mg L^-1. The photothermal conversion efficiency was ~72%. Furthermore, IONs showed high thermogenic stability during the whole process of heating/cooling. To sum up, while the use of IONs in the first bio-window (700-950 nm) presents some concerns, they appear to be good photothermal agents in the second biological window.

Magnetite Nanoparticles and Spheres for Chemo- and Photothermal Therapy of Hepatocellular Carcinoma in vitro

Introduction

We present a multimodal nanoplatforms for the treatment of hepatocellular carcinoma (HCC) in vitro. The nanoplatforms are based on polydopamine (PDA)-coated magnetite nanoparticles (NPs) and spheres (sMAG) with PAMAM dendrimers and functionalized with NHS-PEG-Mal (N-hydroxysuccinimide–polyethylene glycol–maleimide) linker, which allows their functionalization with a folic acid derivative. The nanomaterials bearing a folic acid-targeting moiety show high efficiency in killing cancer cells in the dual chemo- and photothermal therapy (CT-PTT) of the liver cancer cells in comparison to modalities performed separately.

Materials and Methods

All materials are characterized in detail with transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, zeta potential and magnetic measurements. Also, photothermal properties were determined under irradiation of nanoparticles with laser beam of 2 W/cm². The nontoxicity of nanoparticles with doxorubicin and without was checked by WST and LIVE/DEAD assay. Those tests were also used to evaluate materials bearing folic acid and anticancer drug in combined chemo- and photothermal therapy of HCC. Further, the generation of reactive oxygen species profile was also evaluated using flow cytometry test.

Results

Both NPs and sMAG showed high photothermal properties. Nevertheless, the higher photothermal response was found for magnetic spheres. Materials of concentration above 10 µg/mL reveal that their activity was comparable to free doxorubicin. It is worth highlighting that a functionalized magnetic sphere with DOXO more strongly affected the HepG2 cells than smaller functionalized nanoparticles with DOXO in the performed chemotherapy. This can be attributed to the larger size of particles and a different method of drug distribution. In the further stage, both materials were assessed in combined chemo- and photothermal therapy (CT-PTT) which revealed that magnetic spheres were also more effective in this modality than smaller nanoparticles.

Conclusion

Here, we present two types of nanomaterials (nanoparticles and spheres) based on polydopamine and PAMAM dendrimers g.5.0 functionalized with NHS-PEG-Mal linker terminated with folic acid for in vitro hepatocellular carcinoma treatment. The obtained materials can serve as efficient agents for dual chemo- and photothermal therapy of HCC. We also proved that PDA-coated magnetic spheres were more efficient in therapies based on near-infrared irradiation because determined cell viabilities for those materials are lower than for the same concentrations of nanomaterials based on small magnetic nanoparticles.

Multifunctional magnetic iron oxide nanoparticles: an advanced platform for cancer theranostics

Multifunctional magnetic nanoparticles and derivative nanocomposites have aroused great concern for multimode imaging and cancer synergistic therapies in recent years. Among the rest, functional magnetic iron oxide nanoparticles (Fe3O4 NPs) have shown great potential as an advanced platform because of their inherent magnetic resonance imaging (MRI), biocatalytic activity (nanozyme), magnetic hyperthermia treatment (MHT), photo-responsive therapy and drug delivery for chemotherapy and gene therapy. Magnetic Fe3O4 NPs can be synthesized through several methods and easily surface modified with biocompatible materials or active targeting moieties. The MRI capacity could be appropriately modulated to induce response between T1 and T2 modes by controlling the size distribution of Fe3O4 NPs. Besides, small-size nanoparticles are also desired due to the enhanced permeation and retention (EPR) effect, thus the imaging and therapeutic efficiency of Fe3O4 NP-based platforms can be further improved. Here, we firstly retrospect the typical synthesis and surface modification methods of magnetic Fe3O4 NPs. Then, the latest biomedical application including responsive MRI, multimodal imaging, nanozyme, MHT, photo-responsive therapy and drug delivery, the mechanism of corresponding treatments and cooperation therapeutics of multifunctional Fe3O4 NPs are also be explained. Finally, we also outline a brief discussion and perspective on the possibility of further clinical translations of these multifunctional nanomaterials. This review would provide a comprehensive reference for readers to understand the multifunctional Fe3O4 NPs in cancer diagnosis and treatment.

Platelet membrane-coated nanoparticles for targeted drug delivery and local chemo-photothermal therapy of orthotopic hepatocellular carcinoma

Specific targeted drug delivery and controllable release of drugs at tumor regions are two of the main challenges for hepatocellular carcinoma (HCC) therapy, particularly post metastasis. Herein, we present a platelet membrane-facilitated local chemo-photothermal therapy strategy, in which polypyrrole (PPy) nanoparticles act as photothermal agents and along with antitumor drug doxorubicin (DOX) are encapsulated into platelet membranes (PLT-PPy-DOX). The particles are endowed with immune evasiveness and tumor targeting abilities from platelet membranes, and are then intravenously injected into an orthotopic mouse model of HCC. As expected, the PLT-PPy-DOX nanoplatforms were abundant in the tumor tissues. Hyperthermia was generated under laser irradiation (808 nm) not only to ablate tumor cells directly but also to increase the triggered release of DOX. This combination of local chemotherapy and photothermal therapy demonstrated excellent antitumor efficiency in suppressing primary tumor growth and inhibiting tumor metastases. This localized therapy which adopts biocompatible natural cell membranes and good biodegradable organic photothermal agents may provide new insights into designing biomimetic nano-vehicles for personalized therapy of HCC.

Nano-crystalline cellulose-coated magnetic nanoparticles for affinity adsorption of glycoproteins

A new core–shell structured nanomaterial based on Fe₃O₄ nanoparticles and 2,3-dialdehyde nanocrystalline cellulose (DAC) coatings and its high efficiency in the preconcentration of glycoproteins were described in this work.

Targeted multifunctional nanomaterials with MRI, chemotherapy and photothermal therapy for the diagnosis and treatment of bladder cancer

Folate-modified vincristine-loaded polydopamine-coated Fe₃O₄ superparticles are designed as multifunctional nanomaterials for the imaging and treatment of bladder cancer.

Superparamagnetic iron oxide nanoparticulate system: synthesis, targeting, drug delivery and therapy in cancer

Cancer is a global epidemic and is considered a leading cause of death. Various cancer treatments such as chemotherapy, surgery, and radiotherapy are available for the cure but those are generally associated with poor long-term survival rates. Consequently, more advanced and selective methods that have better outcomes, fewer side effects, and high efficacies are highly in demand. Among these is the use of superparamagnetic iron oxide nanoparticles (SPIONs) which act as an innovative kit for battling cancer. Low cost, magnetic properties and toxicity properties enable SPIONs to be widely utilized in biomedical applications. For example, magnetite and maghemite (Fe3O4 and γ-Fe2O3) exhibit superparamagnetic properties and are widely used in drug delivery, diagnosis, and therapy. These materials are termed SPIONs when their size is smaller than 20 nm. This review article aims to provide a brief introduction on SPIONs, focusing on their fundamental magnetism and biological applications. The quality and surface chemistry of SPIONs are crucial in biomedical applications; therefore an in-depth survey of synthetic approaches and surface modifications of SPIONs is provided along with their biological applications such as targeting, site-specific drug delivery and therapy.

A composite of Fe3O4@C and multilevel porous carbon as high-rate and long-life anode materials for lithium ion batteries

The iron oxide-based anode materials are widely studied and reported due to their abundance, low cost, high energy density and environmental friendliness for lithium ion batteries (LIBs). However, the application of LIBs is always limited by the poor rate capability and stability. In order to tackle these issues, a novel material with carbon-encapsulated Fe₃O₄ nanorods stuck together by multilevel porous carbon (Fe₃O₄@C/PC) is prepared through directly carbonizing the Fe-based metal-organic framework under a nitrogen atmosphere. This novel material shows a high specific capacity and rate performance. The initial specific capacity can reach 1789 mAh g^-1 at a current density of 0.1 A g^-1, and the specific capacity still remains 1105.3 mAh g^-1 and 783.5 mAh g^-1 after 150 cycles at the current densities of 0.1 A g^-1 and 1 A g^-1, respectively. Even under a current density as high as 12 A g^-1, the specific capacity can achieve 309 mAh g^-1 after 2000 cycles with an average attenuation rate of 0.019% per cycle. Overall, the simple strategy, low cost and high capacity can make the practical application possible.

Polydopamine-decorated tobacco mosaic virus for photoacoustic/magnetic resonance bimodal imaging and photothermal cancer therapy

Nanotheranostic reagents that integrate magnetic resonance imaging (MRI) and photothermal therapy (PTT) offer a promising strategy for the treatment of human disease. However, classic gadolinium (Gd)-based T1-MRI contrast agents are limited by their low relaxivity. To address this, we produced Gd-loaded Tobacco mosaic virus (TMV) particles coated with the mussel-inspired biopolymer polydopamine (PDA). Such biocompatible nanotheranostic reagents can be used to facilitate PTT, guided by multimodal magnetic resonance/photoacoustic imaging. The r1-relaxivity of the Gd-TMV-PDA particles at 60 MHz was ∼80 mM-1 s-1, compared to 13.63 mM-1 s-1 for the uncoated Gd-TMV particles. The Gd-TMV-PDA particles also promoted strong near-infrared absorption with high photothermal conversion efficiency (28.9%) and demonstrated excellent photoacoustic contrast. Multimodal imaging and PTT resulted in the effective killing of PC-3 prostate cancer cells. Gd-TMV-PDA nanoparticles therefore offer a promising theranostic approach that can now be tested in vivo in cancer models.

Iron oxide nanoparticles promote the migration of mesenchymal stem cells to injury sites

Background

Developing new methods to deliver cells to the injured tissue is a critical factor in translating cell therapeutics research into clinical use; therefore, there is a need for improved cell homing capabilities.

Materials and methods

In this study, we demonstrated the effects of labeling rat bone marrow-derived mesenchymal stem cells (MSCs) with fabricated polydopamine (PDA)-capped Fe₃O₄ (Fe₃O₄@PDA) superparticles employing preassembled Fe₃O₄ nanoparticles as the cores.

Results

We found that the Fe₃O₄@PDA composite superparticles exhibited no adverse effects on MSC characteristics. Moreover, iron oxide nanoparticles increased the number of MSCs in the S-phase, their proliferation index and migration ability, and their secretion of vascular endothelial growth factor relative to unlabeled MSCs. Interestingly, nanoparticles not only promoted the expression of C-X-C chemokine receptor 4 but also increased the expression of the migration-related proteins c-Met and C-C motif chemokine receptor 1, which has not been reported previously. Furthermore, the MSC-loaded nanoparticles exhibited improved homing and anti-inflammatory abilities in the absence of external magnetic fields in vivo.

Conclusion

These results indicated that iron oxide nanoparticles rendered MSCs more favorable for use in injury treatment with no negative effects on MSC properties, suggesting their potential clinical efficacy.

Multifunctional NaYF4:Yb,Er@PE3@Fe3O4 nanocomposites for magnetic-field-assisted upconversion imaging guided photothermal therapy of cancer cells

Magnetic-field-assisted sensitive upconversion luminescence imaging and enhanced photothermal therapeutic efficacy were achieved with multifunctional NaYF₄:Yb,Er@PE3@Fe₃O₄ nanocomposites.

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.

Hollow Polypyrrole Nanospindles for Highly Effective Cancer Therapy

Polypyrrole (PPy) hollow nanostructures continue to attract the interest researchers because of their good biocompatibility, high photothermal conversion efficiency, and excellent stability. The preparation of PPy hollow nanostructures by the hard templating method without complicated post-synthetic treatment and additional oxidizing agents remains a challenge. In this work, we report a facile and novel hard templating method to fabricate hollow PPy nanospindles in which MIL-88(Fe) serves as the template. Fe³⁺ centers in MIL-88(Fe) could induce the polymerization of pyrrole to construct the shell, and MIL-88(Fe) would be decomposed by solvent water. This method did not require any extra oxidizing agents and post-synthetic treatment. Hollow PPy nanospindles exhibit excellent photothermal and drug loading ability, and the therapy effect of cancer was significant. This method provides a new hard templating approach for the synthesis of polymer hollow nanostructures.

One-Step Synthesis of Iodinated Polypyrrole Nanoparticles for CT Imaging Guided Photothermal Therapy of Tumors

Theranostic materials are of great significance to a personalized precise medicine. However, conventional theranostic agents are mainly fabricated by combining presynthesized independent imaging probes and therapeutic agents, suffering from multiple synthesis procedures, poor morphological control, and time/reagent-consuming process. Herein, iodinated polypyrrole (I-PPy) nanoparticles are fabricated via a one-step synthesis strategy combining chemical oxidation and iodination for computed tomography (CT) imaging-guided photothermal therapy. Iodic acid with a high standard electrode potential enables the chemical oxidation polymerization of pyrrole monomers. Meanwhile, the iodination of PPy induced by the corresponding reduction product I₂ takes place during the polymerization process to generate I-PPy nanoparticles. The prepared I-PPy nanoparticles possess a uniform size, excellent colloidal stability, intense near-infrared absorption, strong X-ray attenuation ability, and favorable biocompatibility. The as-synthesized I-PPy nanoparticles not only guarantee remarkable contrast-enhanced CT imaging of blood pool and tumors, but also realize effective tumor suppression in vitro and in vivo by I-PPy nanoparticles-mediated CT imaging-guided photothermal therapy. To the best of the authors' knowledge, it is the first time that multifunctional PPy nanoparticles are fabricated through a one-step synthesis process. The proposed strategy opens up a new way for the fabrication of high-performance theranostic agents via a one-step strategy under mild conditions.

BSA-IrO2 : Catalase-like Nanoparticles with High Photothermal Conversion Efficiency and a High X-ray Absorption Coefficient for Anti-inflammation and Antitumor Theranostics

Intrinsically integrating precise diagnosis, effective therapy, and self-anti-inflammatory action into a single nanoparticle is attractive for tumor treatment and future clinical application, but still remains a great challenge. In this study, bovine serum albumin-iridium oxide nanoparticles (BSA-IrO₂ NPs) with extraordinary photothermal conversion efficiency, good photocatalytic activity, and a high X-ray absorption coefficient were prepared through one-step biomineralization. The nanoparticles allow tumor phototherapy and simultaneous photoacoustic/thermal imaging and computed tomography. More importantly, BSA-IrO₂ NPs can also act as a catalase to protect normal cells against H₂ O₂ -induced reactive oxygen pressure and inflammation while significantly enhancing photoacoustic imaging through microbubble-based inertial cavitation. These remarkable features may open up the exploration iridium-based nanomaterials in theranostics.

Iron Oxide Nanoparticles in Photothermal Therapy

Photothermal therapy is a kind of therapy based on increasing the temperature of tumoral cells above 42 °C. To this aim, cells must be illuminated with a laser, and the energy of the radiation is transformed in heat. Usually, the employed radiation belongs to the near-infrared radiation range. At this range, the absorption and scattering of the radiation by the body is minimal. Thus, tissues are almost transparent. To improve the efficacy and selectivity of the energy-to-heat transduction, a light-absorbing material, the photothermal agent, must be introduced into the tumor. At present, a vast array of compounds are available as photothermal agents. Among the substances used as photothermal agents, gold-based compounds are one of the most employed. However, the undefined toxicity of this metal hinders their clinical investigations in the long run. Magnetic nanoparticles are a good alternative for use as a photothermal agent in the treatment of tumors. Such nanoparticles, especially those formed by iron oxides, can be used in combination with other substances or used themselves as photothermal agents. The combination of magnetic nanoparticles with other photothermal agents adds more capabilities to the therapeutic system: the nanoparticles can be directed magnetically to the site of interest (the tumor) and their distribution in tumors and other organs can be imaged. When used alone, magnetic nanoparticles present, in theory, an important limitation: their molar absorption coefficient in the near infrared region is low. The controlled clustering of the nanoparticles can solve this drawback. In such conditions, the absorption of the indicated radiation is higher and the conversion of energy in heat is more efficient than in individual nanoparticles. On the other hand, it can be designed as a therapeutic system, in which the heat generated by magnetic nanoparticles after irradiation with infrared light can release a drug attached to the nanoparticles in a controlled manner. This form of targeted drug delivery seems to be a promising tool of chemo-phototherapy. Finally, the heating efficiency of iron oxide nanoparticles can be increased if the infrared radiation is combined with an alternating magnetic field.

Near-Infrared-Light-Activatable Nanomaterial-Mediated Phototheranostic Nanomedicines: An Emerging Paradigm for Cancer Treatment

Cancer is one of the most deadly diseases threatening the lives of humans. Although many treatment methods have been developed to tackle cancer, each modality of cancer treatment has its own limitations and drawbacks. The development of minimally invasive treatment modalities for cancers remains a great challenge. Near-infrared (NIR) light-activated nanomaterial-mediated phototherapies, including photothermal and photodynamic therapies, provide an alternative means for spatially and temporally controlled minimally invasive treatments of cancers. Nanomaterials can serve as nanocargoes for the delivery of chemo-drugs, diagnostic contrast reagents, and organic photosensitizers, and can be used to directly generate heat or reactive oxygen species for the treatment of tumors without the need for organic photosensitizers with NIR-light irradiation. Here, current progress in NIR-light-activated nanomaterial-mediated photothermal therapy and photodynamic therapy is summarized. Furthermore, the effects of size, shape, and surface functionalities of nanomaterials on intracellular uptake, macrophage clearance, biodistribution, cytotoxicities, and biomedical efficacies are discussed. The use of various types of nanomaterials, such as gold nanoparticles, carbon nanotubes, graphene, and many other inorganic nanostructures, in combination with diagnostic and therapeutic modalities for solid tumors, is briefly reviewed.

Multifunctional hybrids with versatile types of nanoparticles via self-assembly for complementary tumor therapy

Self-assembly is a promising method for the construction of multifunctional nanohybrids for biomedical application. In this work, self-assembled multifunctional nanohybrids with a controllable disassembly property have been successfully fabricated. By modification with cyclodextrin (CD)-decorated ethylenediamine-functionalized poly(glycidyl methacrylate) (PGED), CD groups and polycations were conjugated onto Au nanorods (Au NRs) or Fe3O4 nanoparticles (denoted as Au-PGED-CD or Fe3O4-PGED-CD), and different SiO2@Fe3O4-PGED (SFP) or SiO2@Au-PGED (SAP) nanohybrids were readily fabricated by the host-guest interaction between Au-PGED-CD or Fe3O4-PGED-CD and adamantyl (Ad)-functionalized chiral silica NRs under mild conditions. The DNA condensation ability of the polycation, the photothermal effects of Au NRs or Fe3O4 nanoparticles, as well as the unique structure of chiral silica NRs were integrated into one nanohybrid. Such nanohybrids have high gene transfection efficiency and low cytotoxicity. The photothermal effects of the nanohybrids could be utilized for photothermal therapy, and also could induce the disassembly of the nanohybrids, which is beneficial for DNA release. The nanohybrids with good transfection performance and excellent photothermal effects were further applied for multimodal therapy. This work presents a flexible strategy for the fabrication of multifunctional nanoplatforms with integration of the advantages of various types of nanoparticles.

Polydopamine-Derivated Hierarchical Nanoplatforms for Efficient Dual-Modal Imaging-Guided Combination in Vivo Cancer Therapy

Exploring multifunctional nanomaterials from biocompatible constituents, with integrated imaging and targeted combination therapeutic modalities of tumors in vivo, provides great prospects for clinical cancer theranostic applications. Here, we report a combination strategy for functionalization of polydopamine (PDA) nanohosts with magnetic response and stimuli-controlled drug release capabilities for in vivo cancer theranostic. The high processability of PDA as nanotemplates and surface coating layers as well as its natural affinity to metals facilitated the sandwich of a compact iron oxide nanoparticle layer into the PDA matrix, realizing enhanced near-infrared (NIR) photothermal conversion and strong superparamagnetic responsiveness. Additionally, the high reactivity of the PDA surface allowed facile linkage with reduction-responsive prodrugs and polyethylene glycol chains for in vivo chemotherapy of cancer. Under the magnetic resonance imaging/photoacoustic imaging dual-modal tumor imaging and active magnetic tumor targeting of the nanoagents in vivo, the effective tumor eradication was achieved via synergetic NIR photothermal ablation and anticancer drug delivery.

Radiotherapy-Sensitized Tumor Photothermal Ablation Using γ-Polyglutamic Acid Nanogels Loaded with Polypyrrole

Development of versatile nanoscale platforms for cancer diagnosis and therapy is of great importance for applications in translational medicine. In this work, we present the use of γ-polyglutamic acid (γ-PGA) nanogels (NGs) to load polypyrrole (PPy) for thermal/photoacoustic (PA) imaging and radiotherapy (RT)-sensitized tumor photothermal therapy (PTT). First, a double emulsion approach was used to prepare the cystamine dihydrochloride (Cys)-cross-linked γ-PGA NGs. Next, the cross-linked NGs served as a reactor to be filled with pyrrole monomers that were subjected to in situ oxidation polymerization in the existence of Fe(III) ions. The formed uniform PPy-loaded NGs having an average diameter of 38.9 ± 8.6 nm exhibited good water-dispersibility and colloid stability. The prominent near-infrared (NIR) absorbance feature due to the loaded PPy endowed the NGs with contrast enhancement in PA imaging. The hybrid NGs possessed excellent photothermal conversion efficiency (64.7%) and stability against laser irradiation, and could be adopted for PA imaging and PTT of cancerous cells and tumor xenografts. Importantly, we also explored the cooperative PTT and X-ray radiation-mediated RT for enhanced tumor therapy. We show that PTT of tumors can be more significantly sensitized by RT using the sequence of laser irradiation followed by X-ray radiation as compared to using the reverse sequence. Our study suggests a promising theranostic platform of hybrid NGs that may be potentially utilized for PA imaging and combination therapy of different types of tumors.

Fabricating High-Performance T2-Weighted Contrast Agents via Adjusting Composition and Size of Nanomagnetic Iron Oxide

Magnetic relaxation switch demonstrated that the aggregated nanomagnetic iron oxide (NMIO) nanocrystal possessed a lower T₂ value and better relaxivity compared with monodispersed NMIO nanocrystal. However, we found that NMIO nanoclusters (NMIONCs) showed a different magnetic resonance (MR) imaging property in comparison with NMIO nanocrystals. Herein, three types of NMIONCs were used to explore the effects of size and compositions on the variations of magnetism and MR contrast ability. It was found that the transverse relaxation rate (r₂) of NMIONCs depended on the contact area between particles and water molecules. The smaller size and higher solubility could carry out higher contact area between NMIONCs and water molecules. Therefore, the monodispersed NMIONC showed a better T₂ contrast ability in comparison with the aggregated NMIONC. In addition, for NMIONCs with the same composition, the magnetism and contrast ability gradually increased with the particle size decreasing. In vivo, NMIONCs that possessed the best solubility and the smallest size showed the most effective MR contrast effect for the liver region of mice. As a result, the size and composition of NMIONCs played important roles for enhancing contrast behavior. This study provides a new idea to develop high-performance T₂ contrast agents by modulating the size and composition of particles.

Tuning the Distance of Rattle-Shaped IONP@Shell-in-Shell Nanoparticles for Magnetically-Targeted Photothermal Therapy in the Second Near-Infrared Window

Construction of multifunctional nanoparticles (NPs) with near-infrared (NIR) plasmonic responses is considered a versatile and multifaceted platform for several biomedical applications. Herein, a double layer of Au/Ag alloy on the surface of truncated octahedral iron oxide NPs (IONPs) was prepared and the distance between the layers was controlled to exhibit broad and strong NIR absorption. The rattle-shaped IONP@shell-in-shell nanostructure showed light-response to the NIR biological window from 650 to 1300 nm for photothermal therapy (PTT) and magnetic guidance for hyperthermia and magnetic resonance imaging (MRI) diagnosis. Exposing the aqueous solution of IONP@shell-in-shell to a 1064 nm diode laser, its heat conversion efficiency was ∼28.3%. The in vitro cell viability at a gold concentration of 100 ppm was ∼85%, and decreased to ∼16% when the cells were treated with the NIR irradiation and magnetic attraction. T₂-weighted MRI images showed a clear accumulation of IONP@shell-in-shell at the tumor site with magnetic attraction. In vivo luminescence tumor images explained that the IONP@shell-in-shell could reduce the U87MG-luc2 cancer cell proliferation in mice with the NIR irradiation and magnetic attraction. These results indicate the IONP@shell-in-shell as a promising nanomedicine for PTT, magnetic targeting, and magnetic resonance imaging (MRI).