Accurate and Real-Time Temperature Monitoring during MR Imaging Guided PTT

Thermoelectric-Feedback Nanocomposite Hydrogel for Temperature-Synchronized Monitoring and Regulation in Accurate Photothermal Therapy

Photothermal therapy (PTT) is a promising approach for tumor ablation and cancer treatment. However, controlling the therapeutic temperature during treatment remains challenging, and imprecise thermal regulation can harm adjacent healthy tissues, reduce therapeutic accuracy, and promote the thermotolerance of cellular phenotypes, potentially leading to tumor invasion and recurrence. Although existing methods provide basic temperature control by adjusting irradiation power and photothermal agent dosing, they lack real-time temperature monitoring and feedback control capabilities, underscoring the urgent need for more integrated and precise PTT systems. In this context, an innovative photothermoelectric (PTE) cobalt-infused chitosan (CS) nanocomposite hydrogel (PTE-Co@CS) is developed for precise temperature-regulated PTT, exhibiting desirable mechanical properties and exceptional biocompatibility. Enhanced by embedded nanoparticles, PTE-Co@CS demonstrates superior photothermal conversion efficiency compared with existing methods, while also featuring thermoelectric responsiveness and increased sensitivity to photostimuli. Its advantageous PTE response characteristics ensure a linear correlation between temperature shifts and resistance changes (e.g., R2 = 0.99919 at 0.5 W cm⁻2), enabling synchronized qualitative and quantitative control of PTT temperature through electrical signal monitoring. This allows for real-time monitoring and regulation during PTT, effectively addressing the issue of uncontrollable temperatures and improving therapeutic efficacy.

Biomimetic MDSCs membrane coated black phosphorus nanosheets system for photothermal therapy/photodynamic therapy synergized chemotherapy of cancer

Photothermal therapy is favored by cancer researchers due to its advantages such as controllable initiation, direct killing and immune promotion. However, the low enrichment efficiency of photosensitizer in tumor site and the limited effect of single use limits the further development of photothermal therapy. Herein, a photo-responsive multifunctional nanosystem was designed for cancer therapy, in which myeloid-derived suppressor cell (MDSC) membrane vesicle encapsulated decitabine-loaded black phosphorous (BP) nanosheets (BP@ Decitabine @MDSCs, named BDM). The BDM demonstrated excellent biosafety and biochemical characteristics, providing a suitable microenvironment for cancer cell killing. First, the BDM achieves the ability to be highly enriched at tumor sites by inheriting the ability of MDSCs to actively target tumor microenvironment. And then, BP nanosheets achieves hyperthermia and induces mitochondrial damage by its photothermal and photodynamic properties, which enhancing anti-tumor immunity mediated by immunogenic cell death (ICD). Meanwhile, intra-tumoral release of decitabine induced G2/M cell cycle arrest, further promoting tumor cell apoptosis. In vivo, the BMD showed significant inhibition of tumor growth with down-regulation of PCNA expression and increased expression of high mobility group B1 (HMGB1), calreticulin (CRT) and caspase 3. Flow cytometry revealed significantly decreased infiltration of MDSCs and M2-macrophages along with an increased proportion of CD4+, CD8+ T cells as well as CD103+ DCs, suggesting a potentiated anti-tumor immune response. In summary, BDM realizes photothermal therapy/photodynamic therapy synergized chemotherapy for cancer.

Dressing and undressing MOF nanophotosensitizers to manipulate phototoxicity for precise therapy of tumors

Photodynamic therapy (PDT) is a clinically approved treatment for tumors, and it relies on the phototoxicity of photosensitizers by producing reactive oxygen species (ROS) to destroy cancer cells under light irradiation. However, such phototoxicity is a double-edged sword, which is also harmful to normal tissues. To manipulate phototoxicity and improve the therapy effect, herein we have proposed a dressing-undressing strategy for de-activating and re-activating therapy functions of photosensitizer nanoparticles. One kind of metal organic framework (PCN-224), which is composed of Zr(IV) cation and tetrakis (4-carboxyphenyl) porphyrin (TCPP), has been prepared as a model of photosensitizer, and it has size of ∼70 nm. These PCN-224 nanoparticles are subsequently coated with a mesoporous organic silica (MOS) shell containing tetrasulfide bonds (-S-S-S-S-), realizing the dressing of PCN-224. MOS shell has the thickness of ∼20 nm and thus can block 1O2 (diffusion distance: <10 nm), deactivating the phototoxicity and preventing the damage to skin and eyes. Furthermore, PCN-224@MOS can be used to load chemotherapy drug (DOX·HCl). When PCN-224@MOS-DOX are mixed with glutathione (GSH), MOS shell with -S-S-S-S- bonds can be reduced by GSH and then be decomposed, which results in the undressing and then confers the exposure of PCN-224 with good PDT function as well as the release of DOX. When PCN-224@MOS-DOX dispersion is injected into the mice and accumulated in the tumor, endogenous GSH also confers the undressing of PCN-224@MOS-DOX, realizing the in-situ activation of PDT and chemotherapy for tumor. Therefore, the present study not only demonstrates a general dressing-undressing strategy for manipulating phototoxicity of photosensitizers, but also provide some insights for precise therapy of tumors without side-effects. STATEMENT OF SIGNIFICANCE: Photosensitizers can generate reactive oxygen species (ROS) under light radiation to destroy cancer cells. However, this phototoxicity is a double-edged sword and also harmful to normal tissues such as the skin and eyes. To control phototoxicity and improve therapeutic efficacy, we prepared a PCN-224@MOS-DOX nanoplatform and proposed a dressing and undressing strategy to deactivate and reactivate the therapeutic function of the photosensitizer nanoparticles. The MOS shell can block the diffusion of 1O2, eliminate phototoxicity, and prevent damage to the skin and eyes. When injected into mice and accumulated in tumors, PCN-224@MOS-DOX dispersions are endowed with an endogenous GSH-driven undressing effect, achieving in situ activation of PDT and tumor chemotherapy.

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.

Marriage of a Dual-Plasmonic Interface and Optical Microfiber for NIR-II Cancer Theranostics

The use of light as a powerful tool for disease treatment has introduced a new era in tumor treatment and provided abundant opportunities for light-based tumor theranostics. This work reports a photothermal theranostic fiber integrating cancer detection and therapeutic functions. Its self-heating effect can be tuned at ultralow powers and used for self-heating detection and tumor ablation. The fiber, consisting of a dual-plasmonic nanointerface and an optical microfiber, can be used to distinguish cancer cells from normal cells, quantify cancer cells, perform hyperthermal ablation of cancer cells, and evaluate the ablation efficacy. Its cancer cell ablation rate reaches 89% in a single treatment. In vitro and in vivo studies reveal quick, deep-tissue photonic hyperthermia in the NIR-II window, which can markedly ablate tumors. The marriage of a dual-plasmonic nanointerface and an optical microfiber presents a novel paradigm in photothermal therapy, offering the potential to surmount the challenges posed by limited light penetration depth, nonspecific accumulation in normal tissues, and inadvertent damage in current methods. This work thus provides insight for the exploration of an integrated theranostic platform with simultaneous functions in cancer diagnostics, therapeutics, and postoperative monitoring for future practical applications.

Gold nanoparticle-mediated photothermal therapy guidance with multi-wavelength photomagnetic imaging

Difficulty in heating tumors with high spatial selectivity while protecting surrounding healthy tissues from thermal harm is a challenge for cancer photothermal treatment (PTT). To mitigate this problem, PTT mediated by photothermal agents (PTAs) has been established as a potential therapeutic technique to boost selectivity and reduce damage to surrounding healthy tissues. Various gold nanoparticles (AuNP) have been effectively utilized as PTAs, mainly using strategies to target cancerous tissue and increase selective thermal damage. Meanwhile, imaging can be used in tandem to monitor the AuNP distribution and guide the PTT. Mainly, the parameters impacting the induced temperature can be determined using simulation tools before treatment for effective PTT. However, accurate simulations can only be performed if the amount of AuNPs accumulated in the tumor is known. This study introduces Photo-Magnetic Imaging (PMI), which can appropriately recover the AuNP concentration to guide the PTT. Using multi-wavelength measurements, PMI can provide AuNP concentration based on their distinct absorption spectra. Tissue-simulating phantom studies are conducted to demonstrate the potential of PMI in recovering AuNP concentration for PTT planning. The recovered AuNP concentration is used to model the temperature increase accurately in a small inclusion representing tumor using a multiphysics solver that takes into account the light propagation and heat diffusion in turbid media.

Twisted Optical Micro/Nanofibers Enabled Detection of Subtle Temperature Variation

The detection of subtle temperature variation plays an important role in many applications, including proximity sensing in robotics, temperature measurements in microfluidics, and tumor monitoring in healthcare. Herein, a flexible miniaturized optical temperature sensor is fabricated by embedding twisted micro/nanofibers in a thin layer of polydimethylsiloxane. Enabled by the dramatic change of the coupling ratio under subtle temperature variation, the sensor exhibits an ultrahigh sensitivity (-30 nm/°C) and high resolution (0.0012 °C). As a proof-of-concept demonstration, a robotic arm equipped with our sensor can avoid undesired collisions by detecting the subtle temperature variation caused by the existence of a human. Moreover, benefiting from the miniaturized and engineerable sensing structure, real-time measurement of subtle temperature variation in microfluidic chips is realized. These initial results pave the way toward a category of optical sensing devices ranging from robotic skin to human-machine interfaces and implantable healthcare sensors.

Mesoporous polydopamine delivery system for intelligent drug release and photothermal-enhanced chemodynamic therapy using MnO2 as gatekeeper

The non-specific leakage of drugs from nanocarriers seriously weakened the safety and efficacy of chemotherapy, and it was very critical of constructing tumor microenvironment (TME)-responsive delivery nanocarriers, achieving the modulation release of drugs. Herein, using manganese dioxide (MnO2) as gatekeeper, an intelligent nanoplatform based on mesoporous polydopamine (MPDA) was developed to deliver doxorubicin (DOX), by which the DOX release was precisely controlled, and simultaneously the photothermal therapy (PTT) and chemodynamic therapy (CDT) were realized. In normal physiological environment, the stable MnO2 shell effectively avoided the leakage of DOX. However, in TME, the overexpressed glutathione (GSH) degraded MnO2 shell, which caused the DOX release. Moreover, the photothermal effect of MPDA and the Fenton-like reaction of the generated Mn2+ further accelerated the cell death. Thus, the developed MPDA-DOX@MnO2 nanoplatform can intelligently modulate the release of DOX, and the combined CDT/PTT/chemotherapy possessed high-safety and high-efficacy against tumors.

Nanomedicine-Enabled/Augmented Cell Pyroptosis for Efficient Tumor Nanotherapy

The terrible morbidity and mortality of malignant tumors urgently require innovative therapeutics, especially for apoptosis-resistant tumors. Pyroptosis, a pro-inflammatory form of programmed cell death (PCD), is featured with pore formation in plasma membrane, cell swelling with giant bubbles, and leakage of cytoplasmic pro-inflammatory cytokines, which can remodel the tumor immune microenvironment by stimulating a "cold" tumor microenvironment to be an immunogenic "hot" tumor microenvironment, and consequently augment the therapeutic efficiency of malignant tumors. Benefiting from current advances in nanotechnology, nanomedicine is extensively applied to potentiate, enable, and augment pyroptosis for enhancing cancer-therapeutic efficacy and specificity. This review provides a concentrated summary and discussion of the most recent progress achieved in this emerging field, highlighting the nanomedicine-enabled/augmented specific pyroptosis strategy for favoring the construction of next-generation nanomedicines to efficiently induce PCD. It is highly expected that the further clinical translation of nanomedicine can be accelerated by inducing pyroptotic cell death based on bioactive nanomedicines.

Photothermal conversion and transfer in photothermal therapy: From macroscale to nanoscale

Photothermal therapy (PTT) is a promising alternative therapy for benign or even malignant tumors. To improve the selective heating of tumor cells, target-specific photothermal conversion agents are often included, especially nanoparticles. Meanwhile, some indirect methods by manipulating the radiation and heat delivery are also adopted. Therefore, to gain a clear understanding of the mechanism, and to improve the controllability of PTT, a few issues need to be clarified, including bioheat and radiation transfer, localized and collective heating of nanoparticles, etc. In this review, we provide an introduction to the typical bioheat transfer and radiation transfer models along with the dynamic thermophysical properties of biological tissue. On this basis, we reviewed the most recent advances in the temperature control methods in PTT from macroscale to nanoscale. Most importantly, a comprehensive introduction of the localized and collective heating effects of nanoparticle clusters is provided to give a clear insight into the mechanism for PPT from the microscale and nanoscale point of view.

Nanocomposites based on lanthanide-doped upconversion nanoparticles: diverse designs and applications

Lanthanide-doped upconversion nanoparticles (UCNPs) have aroused extraordinary interest due to the unique physical and chemical properties. Combining UCNPs with other functional materials to construct nanocomposites and achieve synergistic effect abound recently, and the resulting nanocomposites have shown great potentials in various fields based on the specific design and components. This review presents a summary of diverse designs and synthesis strategies of UCNPs-based nanocomposites, including self-assembly, in-situ growth and epitaxial growth, as well as the emerging applications in bioimaging, cancer treatments, anti-counterfeiting, and photocatalytic fields. We then discuss the challenges, opportunities, and development tendency for developing UCNPs-based nanocomposites.

Near-Infrared Light-Activated Oxygen Generator a Multidynamic Photo-Nanoplatform for Effective Anti-Cutaneous Squamous Cell Carcinoma Treatment

Introduction

Nanophototherapy has emerged as a novel and promising therapeutic strategy for cancer treatment; however, its efficacy in dermatological tumors and precancerous lesions remains severely limited. This study aimed to use the gas-liquid injection technique to fully utilize the synergistic photodynamic therapy (PDT)/photothermal therapy (PTT) of nanomaterials to enhance the antitumor effect.

Methods

A novel oxygen-generating nanocomposite (TSL-IR820-CAT) was synthesized by encapsulating the photosensitizer IR820 and catalase (CAT) using a matrix encapsulation method based on thermosensitive liposomes (TSL).-The liquid injection technology enhances the treatment of cutaneous squamous cell carcinoma (cSCC). The combined PDT/PTT therapeutic effect of TSL-IR820-CAT on cSCC was investigated using in vivo and in vitro experiments.

Results

TSL-IR820-CAT, with good stability, efficient drug release, and photothermal conversion ability, was successfully developed. Nanoparticles injected through a needle-free syringe efficiently accumulate in the tumor tissue. As TSL-IR820-CAT was consumed by A431 cells, some of it localized to the mitochondria and produced oxygen to relieve hypoxia, thereby enhancing the efficacy of PDT. PDT/PTT combination therapy resulted in irreversible apoptosis and inhibited cSCC growth. TSL-IR820-CAT coupled with gas-liquid injection was free from apparent systemic side effects.

Conclusion

This article discusses new strategies and ideas for treating skin tumors and has significant application value.

Ultrasmall PEI-Decorated Bi2Se3 Nanodots as a Multifunctional Theranostic Nanoplatform for in vivo CT Imaging-Guided Cancer Photothermal Therapy

Bi-based nanomaterials, such as Bi2Se3, play an important part in biomedicine, such as photothermal therapy (PTT) and computed tomography (CT) imaging. Polyethylenimine (PEI)-modified ultrasmall Bi2Se3 nanodots were prepared using an ultrafast synthetic method at room temperature (25°C). Bi2Se3 nanodots exhibited superior CT imaging performance, and could be used as effective photothermal reagents owing to their broad absorption in the ultraviolet-visible-near infrared region. Under irradiation at 808 nm, PEI-Bi2Se3 nanodots exhibited excellent photothermal-conversion efficiency of up to 41.3%. Good biocompatibility and significant tumor-ablation capabilities were demonstrated in vitro and in vivo. These results revealed that PEI-Bi2Se3 nanodots are safe and a good nanotheranostic platform for CT imaging-guided PTT of cancer.

Manganese Ferrite Nanoparticles Encapsulated into Vitamin E/Sphingomyelin Nanoemulsions as Contrast Agents for High-Sensitive Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is one of the most powerful non-invasive imaging modalities used in clinics due to its great spatial resolution and excellent soft-tissue contrast, though still less sensitive than other techniques such as the nuclear imaging modalities. This lack of sensitivity can be improved with the use of contrast agents based on nanomaterials. In recent years, researchers have focused on the development of magnetic nanoparticles, given their role as enhancers of the contrast signal based on the magnetic resonance. Manganese ferrite nanoparticles stand out, given their high magnetic susceptibility and magnetic soft nature. Herein, 10 nm MnFe₂ O₄ nanoparticles, functionalized with the natural antioxidant vitamin E (VitE-MFO) are encapsulated into simple, biodegradable and non-toxic nanoemulsions (NEs), by a reproducible one-step method obtaining stable 150 nm-sized magnetic nanoemulsions (VitE-MFO-NEs). After encapsulation, the superparamagnetic properties of VitE-MFO are maintained and MR imaging studies reveal an extremely high transverse relaxivity for VitE-MFO-NEs (652.9 × 10^-3  m^-1  s^-1 ), twofold higher than VitE-MFO value. Moreover, VitE-MFO-NEs show great in vivo biocompatibility and good signal in in vivo and ex vivo MRI, which indicates their great potential for biomedical imaging enhancing the negative MR contrast and significantly improving the sensitivity of MRI.

Selenium Vacancy Engineering Using Bi2Se3 Nanodots for Boosting Highly Efficient Photonic Hyperthermia

Despite bismuth-based energy conversion nanomaterials having attracted extensive attention for nanomedicine, the nanomaterials suffer from major shortcomings including low tumor accumulation, long internal retention time, and undesirable photothermal conversion efficiency (PCE). To combat these challenges, bovine serum albumin and folic acid co-modified Bi2Se3 nanomedicine with rich selenium vacancies (abbreviated as VSe-BS) was fabricated for the second near-infrared (NIR-II) light-triggered photonic hyperthermia. More importantly, selenium vacancies on the crystal planes (0 1 5) and (0 1 11) of VSe-BS with similar formation energies could be distinctively observed via aberration-corrected scanning transmission electron microscopy images. The defect engineering endows VSe-BS with enhanced conductivity, making VSe-BS possess outstanding PCE (54.1%) in the NIR-II biowindow and desirable photoacoustic imaging performance. Tumor ablation studies indicate that VSe-BS possesses satisfactory therapeutic outcomes triggered by NIR-II light. These findings give rise to inspiration for further broadening the biological applications of defect engineering bismuth-based nanomaterials.

Rapidly clearable MnCo2O4@PAA as novel nanotheranostic agents for T1/T2 bimodal MRI imaging-guided photothermal therapy

Integrating multi-modal imaging and therapy functions into a nanoplatform has been recognized as a promising strategy for cancer theranostics with high accuracy and efficiency. However, there are still some challenges, such as the complicated synthesis process and instability. Herein, we successfully prepared clearable MnCo₂O₄ nanodots modified with polyacrylic acid (MnCo₂O₄@PAA) as nanoagents for T₁/T₂ bimodal MRI imaging-guided PTT. Owing to their intrinsic magnetic properties, single MnCo₂O₄@PAA nanomaterials can serve as contrasts for T₁/T₂ bimodal MRI, providing precise diagnotic information. Moreover, excellent absorption in the NIR biowindow endows MnCo₂O₄@PAA with good photothermal performance, and the ultrasmall size of MnCo₂O₄@PAA allows them to penetrate deeply into tumors, resulting in a good anticancer effect in vitro and in vivo. What is more, MnCo₂O₄@PAA can almost be completely cleared from mice at 7 d postinjection, implying their negligible long-term toxicity. These findings demonstrate that MnCo₂O₄@PAA are promising nanoagents for cancer diagnosis and treatment, which have great potential for clinical applications.

A natural anthocyanin-based multifunctional theranostic agent for dual-modal imaging and photothermal anti-tumor therapy

Nowadays, cancer is one of the most serious diseases threatening the health of human beings, and imaging-guided photothermal therapy (PTT) is rapidly emerging as a potent oncotherapy strategy due to its unique advantages of high efficiency, noninvasiveness, visualization, and accuracy. In this study, a multifunctional nanoplatform based on gadolinium ion chelated natural anthocyanins (ACNs) is reported, which can be used not only as an excellent photoacoustic/magnetic resonance (PA/MR) dual-modal contrast agent but also for imaging-guided tumor PTT. The nanoparticles obtained have a suitable size, good dispersity, and physiological stability. The excellent biocompatibility and remarkable photothermal effect of the nanoparticles in vitro were demonstrated by CCK-8 assays and co-staining experiments. Moreover, the magnetic resonance imaging (MRI) and photoacoustic imaging (PAI) results obtained in vivo showed that the nanoparticles were ideal dual-modal contrast agents whether given by intravenous or intratumoral injection. After intratumoral injection, the dual-modal PAI/MRI was used for determining the maximum diffusion time of the probe in the tumor site to guide laser treatment, achieving complete tumor elimination without normal tissue injury. Importantly, ACN is a natural compound extracted from black carrots, possessing native biocompatibility and biodegradability, which was further proved by the results of the detailed safety evaluation. Overall, the as-prepared nanoparticles displayed significant tumor diagnosis and treatment effects while mitigating biosafety concerns, and thus this was found to be a promising nanotherapeutic method for cancer treatment.

Thermal analysis of laser irradiation-gold nanorod combinations at 808 nm, 940 nm, 975 nm and 1064 nm wavelengths in breast cancer model

Background

Photothermal therapy is currently under the spotlight to improve the efficacy of minimally invasive thermal treatment of solid tumors. The interplay of several factors including the radiation wavelengths and the nanoparticle characteristics underlie the thermal outcome. However, a quantitative thermal analysis in in vivo models embedding nanoparticles and under different near-infrared (NIR) wavelengths is missing.

Purpose

We evaluate the thermal effects induced by different combinations of NIR laser wavelengths and gold nanorods (GNRs) in breast cancer tumor models in mice.

Materials and methods

Four laser wavelengths within the therapeutic window, i.e., 808, 940, 975, and 1064 nm were employed, and corresponding GNRs were intratumorally injected. The tissue thermal response was evaluated in terms of temperature profile and time constants, considering the step response of a first-order system as a model.

Results

The 808 nm and 1064 nm lasers experienced the highest temperature enhancements (>24%) in presence of GNRs compared to controls; conversely, 975 nm and 940 nm lasers showed high temperatures in controls due to significant tissue absorption and the lowest temperature difference with and without GNRs (temperature enhancement <10%). The presence of GNRs resulted in small time constants, thus quicker laser-induced thermal response (from 67 s to 33 s at 808 nm).

Conclusions

The thermal responses of different GNR-laser wavelength combinations quantitatively validate the widespread usage of 808 nm laser for nanoparticle-assisted photothermal procedures. Moreover, our results provide insights on other usable wavelengths, toward the identification of an effective photothermal treatment strategy for the removal of focal malignancies.

How do bismuth-based nanomaterials function as promising theranostic agents for the tumor diagnosis and therapy?

The complexity of tumor microenvironment and the diversity of tumors seriously affect the therapeutic effect, the focus, therefore, has gradually been shifted from monotherapy to combination therapy in clinical research in order to improve the curative effect. The synergistic enhancement interactions among multiple monotherapies majorly contribute to the birth of the multi-mode cooperative therapy, whose effect of the treatment is clearly stronger than that of any single therapy. In addition, the accurate diagnosis of the tumour location is also crucial to the treatment. Bismuth-based nanomaterials (NMs) hold great properties as promising theranostic platforms based on their many unique features that include low toxicity, excellent photothermal conversion efficiency as well as high ability of X-ray computed tomography imaging and photoacoustic imaging. In this review, we will introduce briefly the main features of tumor microenvironment first and its effect on the mechanism of nanomedicine actions and present the recent advances of bismuth-based NMs for diagnosis and photothermal therapy-based combined therapies using bismuth-based NMs are presented, which may provide a new way for overcoming drug resistance and hypoxia. At the end, further challenges and outlooks regarding this promising field are discussed accompanied with some design tips for bismuth-based NMs, hoping to provide researchers some inspirations to design safe and effective nanotherapeutic agents for the clinical treatments of cancers.

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

OBJECTIVE

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

OBJECTIVE

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

OBJECTIVE

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

OBJECTIVE

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

An efficient strategy for cancer therapy using a tumor- and lysosome-targeted organic photothermal agent

A dual-targeted organic photothermal agent for tumor cells and lysosomes was developed. In vitro and in vivo experiments demonstrated that it possessed low cytotoxicity, good biological compatibility, and tumor inhibitory effects.

Phenolic-enabled nanotechnology: versatile particle engineering for biomedicine

Phenolics are ubiquitous in nature and have gained immense research attention because of their unique physiochemical properties and widespread industrial use. In recent decades, their accessibility, versatile reactivity, and relative biocompatibility have catalysed research in phenolic-enabled nanotechnology (PEN) particularly for biomedical applications which have been a major benefactor of this emergence, as largely demonstrated by polydopamine and polyphenols. Therefore, it is imperative to overveiw the fundamental mechanisms and synthetic strategies of PEN for state-of-the-art biomedical applications and provide a timely and comprehensive summary. In this review, we will focus on the principles and strategies involved in PEN and summarize the use of the PEN synthetic toolkit for particle engineering and the bottom-up synthesis of nanohybrid materials. Specifically, we will discuss the attractive forces between phenolics and complementary structural motifs in confined particle systems to synthesize high-quality products with controllable size, shape, composition, as well as surface chemistry and function. Additionally, phenolic's numerous applications in biosensing, bioimaging, and disease treatment will be highlighted. This review aims to provide guidelines for new scientists in the field and serve as an up-to-date compilation of what has been achieved in this area, while offering expert perspectives on PEN's use in translational research.

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.

Biomimetic magnetofluorescent ferritin nanoclusters for magnetic resonance and fluorescence-dual modal imaging and targeted tumor therapy

Multiple imaging by combining magnetic resonance (MR) and fluorescence imaging into a single nanosystem displays distinctive merits, which is desirable for precise in vivo imaging. In this work, we proposed a new tumor-targeting dual-modal diagnosis strategy by designing and fabricating a biocompatible nano-erythrocyte and successfully delivering it into in vivo tumors. The novel nano-contrast agent (CMR) was prepared by encapsulating human heavy-chain ferritin (HFn) nanoparticles with Cy5.5 binding and mineralized iron oxide nanoparticles (Fe3O4 NPs) into erythrocyte membranes (RBCs). We demonstrated that the as-prepared CMR displayed excellent biocompatibility with low hepatotoxicity and long blood circulation time. More importantly, by functionalizing the CMR with different types of targeting moieties, the nanosystem could precisely target both subcutaneous and orthotopic tumors, and exhibited excellent MR and fluorescence dual-model imaging ability. Moreover, we demonstrated that the CMR was able to modulate the tumor microenvironment to achieve an efficient antitumor effect.

Inorganic-inorganic nanohybrids for drug delivery, imaging and photo-therapy: recent developments and future scope

Advanced nanotechnology has been emerging rapidly in terms of novel hybrid nanomaterials that have found various applications in day-to-day life for the betterment of the public. Specifically, gold, iron, silica, hydroxy apatite, and layered double hydroxide based nanohybrids have shown tremendous progress in biomedical applications, including bio-imaging, therapeutic delivery and photothermal/dynamic therapy. Moreover, recent progress in up-conversion nanohybrid materials is also notable because they have excellent NIR imaging capability along with therapeutic benefits which would be useful for treating deep-rooted tumor tissues. Our present review highlights recent developments in inorganic-inorganic nanohybrids, and their applications in bio-imaging, drug delivery, and photo-therapy. In addition, their future scope is also discussed in detail.

A biodegradable bismuth–gadolinium-based nano contrast agent for accurate identification and imaging of renal insufficiency in vivo

A biodegradable gadolinium-doped mesoporous bismuth-based nanomaterial is used to diagnose kidneys with dysfunction accurately via magnetic resonance imaging in vivo.

One-for-all intelligent core-shell nanoparticles for tumor-specific photothermal-chemodynamic synergistic therapy

Reasonable management of the one-for-all nanoplatform can facilitate improved cancer therapy. Here, the metal-organic frameworks (MOFs) based on iron(iii) carboxylate material (MIL-101-NH₂) were in situ decorated on stabilized polydopamine nanoparticles (PDANPs), which subsequently loaded glucose oxidase (GOx) via hyaluronic acid (HA) coating to structure the one-for-all intelligent core-shell nanoparticles (HG-MIL@PDANPs). Because of the inner PDANPs, the HG-MIL@PDANPs could realize near-infrared (NIR)-controllable site-specific photothermal therapy (PTT). Additionally, the core-shell nanoparticles exhibited a pH-triggered and NIR-reinforced release of Fe³⁺ and GOx owing to the controllable degradation of the outer shell. Hydroxyl radicals (˙OH) were produced for chemodynamic therapy (CDT) employing the Fe²⁺-driven Fenton reaction, which could be greatly promoted by Fe³⁺-involved glutathione (GSH) depletion and GOx-catalyzed acidity recovery and H₂O₂ self-sufficiency. Moreover, the HA ligand could enhance the tumor accumulation of the HG-MIL@PDANPs through the long blood circulation time and CD44-targeted cell recognition. The ingenious integration of PTT and CDT in one fully equipped system presented excellent synergistic antitumor efficiency in vitro and in vivo with favorable biosafety. The one-for-all intelligent core-shell nanoparticles with CD44 targeting provide a new avenue for engineering on-demand tumor-specific therapy.

Functional gadolinium-based nanoscale systems for cancer theranostics

Cancer theranostics is a new strategy for combating cancer that integrates cancer imaging and treatment through theranostic agents to provide an efficient and safe way to improve cancer prognosis. Design and synthesis of these cancer theranostic agents are crucial since these agents are required to be biocompatible, tumor-specific, imaging distinguishable and therapeutically efficacious. In this regard, several types of gadolinium (Gd)-based nanomaterials have been introduced to combine different therapeutic agents with Gd to enhance the efficacy of therapeutic agents. At the same time, the entire treatment procedure could be monitored via imaging tools due to incorporation of Gd ions, Gd chelates and Gd/other imaging probes in the theranostic agents. This review aims to overview recent advances in the Gd-based nanomaterials for cancer theranostics and perspectives for Gd nanomaterial-based cancer theranostics are provided.