Tumor ablation and nanotechnology

Image-guided Ablative Procedures

Various image-guided ablative procedures include chemical and thermal ablation techniques and irreversible electroporation. These have been used for curative intent for small tumours and palliative intent for debulking, immunogenicity and pain control. Understanding these techniques is critical to avoiding complications and achieving superior clinical outcomes. Additionally, combination with immunotherapy and chemotherapies is rapidly evolving. There are numerous opportunities in interventional radiology to advance ablation techniques and seamlessly integrate into current treatment regimens for both benign and malignant tumours.

Nanoparticle-mediated thermal Cancer therapies: Strategies to improve clinical translatability

Despite significant advances, cancer remains a leading global cause of death. Current therapies often fail due to incomplete tumor removal and nonspecific targeting, spurring interest in alternative treatments. Hyperthermia, which uses elevated temperatures to kill cancer cells or boost their sensitivity to radio/chemotherapy, has emerged as a promising alternative. Recent advancements employ nanoparticles (NPs) as heat mediators for selective cancer cell destruction, minimizing damage to healthy tissues. This approach, known as NP hyperthermia, falls into two categories: photothermal therapies (PTT) and magnetothermal therapies (MTT). PTT utilizes NPs that convert light to heat, while MTT uses magnetic NPs activated by alternating magnetic fields (AMF), both achieving localized tumor damage. These methods offer advantages like precise targeting, minimal invasiveness, and reduced systemic toxicity. However, the efficacy of NP hyperthermia depends on many factors, in particular, the NP properties, the tumor microenvironment (TME), and TME-NP interactions. Optimizing this treatment requires accurate heat monitoring strategies, such as nanothermometry and biologically relevant screening models that can better mimic the physiological features of the tumor in the human body. This review explores the state-of-the-art in NP-mediated cancer hyperthermia, discussing available nanomaterials, their strengths and weaknesses, characterization methods, and future directions. Our particular focus lies in preclinical NP screening techniques, providing an updated perspective on their efficacy and relevance in the journey towards clinical trials.

Advances in Nanomaterials for Immunotherapeutic Improvement of Cancer Chemotherapy

Immuno-stimulative effect of chemotherapy (ISECT) is recognized as a potential alternative to conventional immunotherapies, however, the clinical application is constrained by its inefficiency. Metronomic chemotherapy, though designed to overcome these limitations, offers inconsistent results, with effectiveness varying based on cancer types, stages, and patient-specific factors. In parallel, a wealth of preclinical nanomaterials holds considerable promise for ISECT improvement by modulating the cancer-immunity cycle. In the area of biomedical nanomaterials, current literature reviews mainly concentrate on a specific category of nanomaterials and nanotechnological perspectives, while two essential issues are still lacking, i.e., a comprehensive analysis addressing the causes for ISECT inefficiency and a thorough summary elaborating the nanomaterials for ISECT improvement. This review thus aims to fill these gaps and catalyze further development in this field. For the first time, this review comprehensively discusses the causes of ISECT inefficiency. It then meticulously categorizes six types of nanomaterials for improving ISECT. Subsequently, practical strategies are further proposed for addressing inefficient ISECT, along with a detailed discussion on exemplary nanomedicines. Finally, this review provides insights into the challenges and perspectives for improving chemo-immunotherapy by innovations in nanomaterials.

Computer simulation-based nanothermal field and tissue damage analysis for cardiac tumor ablation

Radiofrequency ablation is a nominally invasive technique to eradicate cancerous or non-cancerous cells by heating. However, it is still hampered to acquire a successful cell destruction process due to inappropriate RF intensities that will not entirely obliterate tumorous tissues, causing in treatment failure. In this study, we are acquainted with a nanoassisted RF ablation procedure of cardiac tumor to provide better outcomes for long-term survival rate without any recurrences. A three-dimensional thermo-electric energy model is employed to investigate nanothermal field and ablation efficiency into the left atrium tumor. The cell death model is adopted to quantify the degree of tissue injury while injecting the Fe3O4 nanoparticles concentrations up to 20% into the target tissue. The results reveal that when nanothermal field extents as a function of tissue depth (10 mm) from the electrode tip, the increasing thermal rates were approximately 0.54362%, 3.17039%, and 7.27397% for the particle concentration levels of 7%, 10%, and 15% compared with no-particle case. In the 7% Fe3O4 nanoparticles, 100% fractional damage index is achieved after ablation time of 18 s whereas tissue annihilation approach proceeds longer to complete for no-particle case. The outcomes indicate that injecting nanoparticles may lessen ablation time in surgeries and prevent damage to adjacent healthy tissue.

Ultrasound contrast agent assisted ultrasonography guidance percutaneous nephrostomy for non-hydronephrotic kidney

BACKGROUND

Given the limited success rate and considerable challenges associated with conventional ultrasonography (US) guidance for percutaneous nephrostomy (PCN) in non-hydronephrotic kidneys, this study proposed a solution with ultrasound contrast agent to enhance the success rate and mitigate the difficulties.

MATERIALS AND METHODS

From January 2017 to August 2023, a total of thirteen patients diagnosed with non-hydronephrotic kidney were included in the study. Following routine ultrasonography examination, no significant dilatation of the renal collecting system was observed. US-guided percutaneous nephrostomy PCN was performed with the assistance of ultrasound contrast agent (UCA). The patients were subsequently monitored to assess the improvement of symptoms and postoperative recovery.

RESULTS

The success rate was found to be 100% for all patients (13/13) and kidneys (20/20). The average volume of UCA solution used was 19 ± 6.7 mL (range, 11-35 mL), while the mean duration of the operation was 18.92 ± 8.96 min (range, 7-36 min). A majority of the patients (12/13) underwent a single puncture procedure. Throughout the follow-up period, no serious complications were observed, and surgery resulted in significant alleviation of symptoms in all patients.

CONCLUSION

The use of UCA-assisted US guidance PCN has been shown to be effective in achieving urinary diversion and alleviating associated clinical symptoms in non-hydronephrotic kidneys. In comparison to traditional methods, this approach demonstrates a high success rate and safety profile, while also offering a simplified operative procedure. Consequently, it presents a novel method and concept for managing non-hydronephrotic kidneys afflicted by urine leakage.

Boosting Microwave Thermo-Dynamic Cancer Therapy of TiMOF via COF-Coating

Microwave (MW) dynamic therapy (MDT) can efficiently eliminate tumor residue resulting from MW thermal therapy. However, MDT is currently in its infancy, and luck of effective MDT sensiters severely limits its clinical therapeutic effect. Herein, based on TiMOF (TM), a high-efficiency MW sensitizer is designed for MW thermo-dynamic therapy. TM can generate heat and cytotoxic reacyive oxygen species (ROS) under MW irradiation and has the potential to be used as an MW sensitizer, while the suboptimal MW dynamic sensitization effect of TM limits its application. Inorder to improve the MW dynamic sensitization performance, a covalent organic framework (COF) with good stability and a large conjugate system is used to cover TM, which is conductive to electron and energy transfer, thus increasing the ROS generation rate and prolonging the ROS lifetime. In addition, loading Ni NPs endow nanomaterials with magnetic resonance imaging capabilities. Therefore, this work develops an MW sensitizer based on TM for the first time, and the mechanism of COF coating to enhance the MW dynamic sensitization of TM is preliminarily explored, which provides a new idea for the further development of MW sensitizer with great potential.

A review on radiofrequency, laser, and microwave ablations and their thermal monitoring through fiber Bragg gratings

Thermal ablation of tumors aims to apply extreme temperatures inside the target tissue to achieve substantial tumor destruction in a minimally invasive manner. Several techniques are comprised, classified according to the type of energy source. However, the lack of treatment selectivity still needs to be addressed, potentially causing two risks: i) incomplete tumor destruction and recurrence, or conversely, ii) damage of the surrounding healthy tissue. Therefore, the research herein reviewed seeks to develop sensing systems based on fiber Bragg gratings (FBGs) for thermal monitoring inside the lesion during radiofrequency, laser, and microwave ablation. This review shows that, mainly thanks to multiplexing and minimal invasiveness, FBGs provide an optimal sensing solution. Their temperature measurements are the feedback to control the ablation process and allow to investigate different treatments, compare their outcomes, and quantify the impact of factors such as proximity to thermal probe and blood vessels, perfusion, and tissue type.

Application of nanotechnology in breast cancer screening under obstetrics and gynecology through the use of CNN and ANFIS

Breast cancer is the leading reason of death among women aged 35 to 54. Breast cancer diagnosis still presents significant challenges, and preventing the disease's most severe symptoms requires early detection. The role of nanotechnology in the tumor-treatment has recently attracted a lot of interest. In cancer therapies, nanotechnology plays a major role in the medication distribution process. Nanoparticles have the ability to target tumors. Nanoparticles are favorable and maybe preferable for usage in tumor detection and imaging due to their incredibly small size. Quantum dots, semiconductor crystals with increased labeling and imaging capabilities for cancer cells, are one of the particles that have received the most research attention. The design of the research is cross-sectional and descriptive. From April through September of 2020, data were gathered at the State Hospital. All pregnant women who came to the hospital throughout the first and second trimesters of the research's data collection were included in the study population. 100 pregnant women between the ages of 20 and 40 who had not yet had a mammogram comprised the research sample. 1100 digitized mammography images are included in the dataset, which was obtained from a hospital. Convolutional neural networks (CNN) were used to scan all images, and breast masses and mass comparisons were made using the malignant-benign categorization. The adaptive neuro-fuzzy inference system (ANFIS) then examined all of the data obtained by CNN in order to identify breast cancer early using inputs based on the nine different inputs. The precision of the mechanism used in this technique to determine the ideal radius value is significantly impacted by the radius value. Nine variables that define breast cancer indicators were utilized as inputs to the ANFIS classifier, which was then used to identify breast cancer. The parameters were given the necessary fuzzy functions, and the combined dataset was applied to train the method. Testing was initially performed by 30% of dataset that was later done with the real data obtained from the hospital. The accuracy of the results for 30% data was 84% (specificity =72.7%, sensitivity =86.7%) and the results for the real data was 89.8% (sensitivity =82.3%, specificity =75.9%), respectively.

Enhanced thrombolytic effect induced by acoustic cavitation generated from nitrogen-doped annealed nanodiamond particles

In biomedical research, ultrasonic cavitation, especially inertial cavitation (IC) has attracted extensive attentions due to its ability to induce mechanical, chemical and thermal effects. Like ultrasound contrast agent (UCA) microbubbles or droplets, acoustic cavitation can be effectively triggered beyond a certain pressure threshold through the interaction between ultrasound and nucleation particles, leading to an enhanced thrombolytic effect. As a newly developed nanocarbon material, nitrogen-doped annealed nanodiamond (N-AND) has shown promising catalytic performance. To further explore its effects on ultrasonic cavitation, N-AND was synthesized at the temperature of 1000 °C. After systematic material characterization, the potential of N-AND to induce enhanced IC activity was assessed for the first time by using passive cavitation detection (PCD). Based on experiments performed at varied material suspension concentration and cycle number, N-AND demonstrated a strong capability to generate significant cavitation characteristics, indicating the formation of stable bubbles from the surface of the materials. Furthermore, N-AND was applied in the in vitro thrombolysis experiments to verify its contribution to ultrasound thrombolysis. The influence of surface hydrophobicity on the cavitation potentials of ND and N-AND was innovatively discussed in combination with the theory of mote-induced nucleation. It is found that the cavitation stability of N-AND was better than that of the commercial UCA microbubbles. This study would provide better understanding of the potential of novel carbonous nanomaterials as cavitation nuclei and is expected to provide guidance for their future biomedical and industrial applications.

Targeted therapy of breast tumor by PLGA-based nanostructures: The versatile function in doxorubicin delivery

Breast carcinoma is a molecularly diverse illness, and it is among the most prominent and often reported malignancies in female across the globe. Surgical intervention, chemotherapy, immunotherapy, gene therapy, and endocrine treatment are among the currently viable treatment options for the carcinoma of breast. Chemotherapy is among the most prevalent cancer management strategy. Doxorubicin (DOX) widely employed as a cytostatic medication for the treatment of a variety of malignancies. Despite its widespread acceptance and excellent efficacy against an extensive line up of neoplasia, it has a variety of shortcomings that limit its therapeutic potential in the previously mentioned indications. Employment of nanoparticulate systems has come up as a unique chemo medication delivery strategy and are being considerably explored for the amelioration of breast carcinoma. Polylactic-co-glycolic acid (PLGA)-based nano systems are being utilized in a number of areas within the medical research and medication delivery constitutes one of the primary functions for PLGA given their inherent physiochemical attributes, including their aqueous solubility, biocompatibility, biodegradability, versatility in formulation, and limited toxicity. Herein along with the different application of PLGA-based nano formulations in cancer therapy, the present review intends to describe the various research investigations that have been conducted to enumerate the effectiveness of DOX-encapsulated PLGA nanoparticles (DOX-PLGA NPs) as a feasible treatment option for breast cancer.

Photodynamic therapy: Innovative approaches for antibacterial and anticancer treatments

Photodynamic therapy is an alternative treatment mainly for cancer but also for bacterial infections. This treatment dates back to 1900 when a German medical school graduate Oscar Raab found a photodynamic effect while doing research for his doctoral dissertation with Professor Hermann von Tappeiner. Unexpectedly, Raab revealed that the toxicity of acridine on paramecium depends on the intensity of light in his laboratory. Photodynamic therapy is therefore based on the administration of a photosensitizer with subsequent light irradiation within the absorption maxima of this substance followed by reactive oxygen species formation and finally cell death. Although this treatment is not a novelty, there is an endeavor for various modifications to the therapy. For example, selectivity and efficiency of the photosensitizer, as well as irradiation with various types of light sources are still being modified to improve final results of the photodynamic therapy. The main aim of this review is to summarize anticancer and antibacterial modifications, namely various compounds, approaches, and techniques, to enhance the effectiveness of photodynamic therapy.

Photodynamic therapy in oral cancer: a review of clinical studies

A significant mortality rate is associated with oral cancer, particularly in cases of late-stage diagnosis. Since the last decades, oral cancer survival rates have only gradually improved despite advances in treatment. This poor success rate is mainly due to the development of secondary tumors, local recurrence, and regional failure. Invasive treatments frequently have a negative impact on the aesthetic and functional outcomes of survivors. Novel approaches are thus needed to manage this deadly disease in light of these statistics. In photodynamic therapy (PDT), a light-sensitive medication called a photosensitizer is given first, followed by exposure to light of the proper wavelength that matches the absorbance band of the photosensitizer. The tissue oxygen-induced cytotoxic free radicals kill tumor cells directly, harm the microvascular structure, and cause inflammatory reactions at the targeted sites. In the case of early lesions, PDT can be used as a stand-alone therapy, and in the case of advanced lesions, it can be used as adjuvant therapy. The current review article discussed the uses of PDT in oral cancer therapy based on recent advances in this field.

Recent Trend of Ultrasound-Mediated Nanoparticle Delivery for Brain Imaging and Treatment

In view of the fact that the blood-brain barrier (BBB) prevents the transport of imaging probes and therapeutic agents to the brain and thus hinders the diagnosis and treatment of brain-related disorders, methods of circumventing this problem (e.g., ultrasound-mediated nanoparticle delivery) have drawn much attention. Among the related techniques, focused ultrasound (FUS) is a favorite means of enhancing drug delivery via transient BBB opening. Photoacoustic brain imaging relies on the conversion of light into heat and the detection of ultrasound signals from contrast agents, offering the benefits of high resolution and large penetration depth. The extensive versatility and adjustable physicochemical properties of nanoparticles make them promising therapeutic agents and imaging probes, allowing for successful brain imaging and treatment through the combined action of ultrasound and nanoparticulate agents. FUS-induced BBB opening enables nanoparticle-based drug delivery systems to efficiently access the brain. Moreover, photoacoustic brain imaging using nanoparticle-based contrast agents effectively visualizes brain morphologies or diseases. Herein, we review the progress in the simultaneous use of nanoparticles and ultrasound in brain research, revealing the potential of ultrasound-mediated nanoparticle delivery for the effective diagnosis and treatment of brain disorders.

PLGA-based nanoparticles for the treatment of cancer: current strategies and perspectives

Research on cancer treatment is always of great importance because of the extensive and difficult treatment options and side effects of chemotherapeutic agents. Due to this, novel techniques for cancer treatment are the need of the day. Nowadays, nanotechnology is of great interest for its applications as diagnostic tools, theragnostic, contrasting agents, and vehicles for delivering drugs. Nanoparticles (NPs) are made up of biocompatible and biodegradable polymers that improve the pharmacokinetic and pharmacodynamic properties of drugs, reduce side effects, improve stability, prolong the release of drug, and reduce the dosing frequency. Poly (lactic-co-glycolic acid) (PLGA) is FDA-approved synthetic polymer which can be used to formulate NPs that can be targeted to a specific site for the safe and effective delivery of drugs. PLGA-based NPs can be used for a variety of cancer therapies including tumor-targeted drug delivery, gene therapy, hyperthermia, and photodynamic therapy. This article discusses the method of preparation, characterization, encapsulation of chemotherapeutic drugs, effect of physicochemical properties of PLGA- based NPs, and how we can exploit these aspects through various methods of preparation for drug loading, biodistribution, target specificity, and their use in cancer treatment. Along with these targeting strategies, gene therapy, cancer immunotherapy, and various applications have also been discussed. This article also aims to discuss the incorporation of diagnostic tools and therapeutic moiety in one versatile formulation of PLGA-NPs and the difficulties faced in translating this promising tool to clinical use.

Zinc Oxide Nanoparticles: A Review on Its Applications in Dentistry

Nanotechnology in modern material science is a research hot spot due to its ability to provide novel applications in the field of dentistry. Zinc Oxide Nanoparticles (ZnO NPs) are metal oxide nanoparticles that open new opportunities for biomedical applications that range from diagnosis to treatment. The domains of these nanoparticles are wide and diverse and include the effects brought about due to the anti-microbial, regenerative, and mechanical properties. The applications include enhancing the anti-bacterial properties of existing restorative materials, as an anti-sensitivity agent in toothpastes, as an anti-microbial and anti-fungal agent against pathogenic oral microflora, as a dental implant coating, to improve the anti-fungal effect of denture bases in rehabilitative dentistry, remineralizing cervical dentinal lesions, increasing the stability of local drug delivery agents and other applications.

Green-Synthesized Silver Nanoparticle-Assisted Radiofrequency Ablation for Improved Thermal Treatment Distribution

Thermal ablation therapy is known as an advantageous alternative to surgery allowing the treatment of multiple tumors located in hard-to-reach locations or treating patients with medical conditions that are not compatible with surgery. Appropriate heat propagation and precise control over the heat propagation is considered a weak point of thermal ablation therapy. In this work, silver nanoparticles (AgNPs) are used to improve the heat propagation properties during the thermal ablation procedure. Green-synthesized silver nanoparticles offer several attractive features, such as excellent thermal conductivity, biocompatibility, and antimicrobial activity. A distributed multiplexed fiber optic sensing system is used to monitor precisely the temperature change during nanoparticle-assisted radiofrequency ablation. An array of six MgO-based nanoparticles doped optical fibers spliced to single-mode fibers allowed us to obtain the two-dimensional thermal maps in a real time employing optical backscattering reflectometry at 2 mm resolution and 120 sensing points. The silver nanoparticles at 5, 10, and 20 mg/mL were employed to investigate their heating effects at several positions on the tissue regarding the active electrode. In addition, the pristine tissue and tissue treated with agarose solution were also tested for reference purposes. The results demonstrated that silver nanoparticles could increase the temperature during thermal therapies by propagating the heat. The highest temperature increase was obtained for 5 mg/mL silver nanoparticles introduced to the area close to the electrode with a 102% increase of the ablated area compared to the pristine tissue.

Deep neural networks for magnetic resonance elastography acceleration in thermal ablation monitoring

PURPOSE

To develop a deep neural network for accelerating magnetic resonance elastography (MRE) acquisition, to validate the ability to generate reliable MRE results with the down-sampled k-space data, and to demonstrate the feasibility of the proposed method in monitoring the stiffness changes during thermal ablation in a phantom study.

MATERIALS AND METHODS

MRE scans were performed with 60 Hz excitation on porcine ex-vivo liver gel phantoms in a 0.36T MRI scanner to generate the training dataset. The acquisition protocol was based on a spin-echo MRE pulse sequence with tailored motion-sensitive gradients to reduce echo time (TE). A U-Net based deep neural network was developed and trained to interpolate the missing data from down-sampled k-space. We calculated the errors of 80 sets magnitude/phase images reconstructed from the zero-filled, compressive sensing (CS) and deep learning (DL) method for comparison. The peak signal-to-noise rate (PSNR) and structural similarity (SSIM) of the magnitude/phase images were also calculated for comparison. The stiffness changes were recorded before, during, and after ablation. The mean stiffness values over the region of interest (ROI) were compared between the elastograms reconstructed from the fully-sampled k-space and interpolated k-space after thermal ablation.

RESULTS

The mean absolute error (MAE), PSNR, and SSIM of the proposed deep learning approach were significantly better than the results from the zero-filled method (p<0.0001) and CS (p<0.0001). The stiffness changes before and after thermal ablation assessed by the proposed approach (before: 7.7±1.1 kPa, after: 11.9±4.0 kPa, 4.2-kPa increase) gave close agreement with the values calculated from the fully-sampled data (before: 8.0±1.0 kPa, after: 12.6±4.2 kPa, 4.6-kPa increase). In contrast, the stiffness changes computed from the zero-filled method (before: 4.9±1.4 kPa, after: 5.6±2.8 kPa, 0.7-kPa increase) were substantially underestimated.

CONCLUSION

This study demonstrated the capability of the proposed deep learning method for rapid MRE acquisition and provided a promising solution for monitoring the MRI-guided thermal ablation. This article is protected by copyright. All rights reserved.

Multifunctional Iron Oxide Magnetic Nanoparticles for Biomedical Applications: A Review

Due to their good magnetic properties, excellent biocompatibility, and low price, magnetic iron oxide nanoparticles (IONPs) are the most commonly used magnetic nanomaterials and have been extensively explored in biomedical applications. Although magnetic IONPs can be used for a variety of applications in biomedicine, most practical applications require IONP-based platforms that can perform several tasks in parallel. Thus, appropriate engineering and integration of magnetic IONPs with different classes of organic and inorganic materials can produce multifunctional nanoplatforms that can perform several functions simultaneously, allowing their application in a broad spectrum of biomedical fields. This review article summarizes the fabrication of current composite nanoplatforms based on integration of magnetic IONPs with organic dyes, biomolecules (e.g., lipids, DNAs, aptamers, and antibodies), quantum dots, noble metal NPs, and stimuli-responsive polymers. We also highlight the recent technological advances achieved from such integrated multifunctional platforms and their potential use in biomedical applications, including dual-mode imaging for biomolecule detection, targeted drug delivery, photodynamic therapy, chemotherapy, and magnetic hyperthermia therapy.

ROS Pleiotropy in Melanoma and Local Therapy with Physical Modalities

Metabolic energy production naturally generates unwanted products such as reactive oxygen species (ROS), causing oxidative damage. Oxidative damage has been linked to several pathologies, including diabetes, premature aging, neurodegenerative diseases, and cancer. ROS were therefore originally anticipated as an imperative evil, a product of an imperfect system. More recently, however, the role of ROS in signaling and tumor treatment is increasingly acknowledged. This review addresses the main types, sources, and pathways of ROS in melanoma by linking their pleiotropic roles in antioxidant and oxidant regulation, hypoxia, metabolism, and cell death. In addition, the implications of ROS in various physical therapy modalities targeting melanoma, such as radiotherapy, electrochemotherapy, hyperthermia, photodynamic therapy, and medical gas plasma, are also discussed. By including ROS in the main picture of melanoma skin cancer and as an integral part of cancer therapies, a greater understanding of melanoma cell biology is presented, which ultimately may elucidate additional clues on targeting therapy resistance of this most deadly form of skin cancer.

MoS2-based nanocomposites for cancer diagnosis and therapy

Molybdenum is a trace dietary element necessary for the survival of humans. Some molybdenum-bearing enzymes are involved in key metabolic activities in the human body (such as xanthine oxidase, aldehyde oxidase and sulfite oxidase). Many molybdenum-based compounds have been widely used in biomedical research. Especially, MoS2-nanomaterials have attracted more attention in cancer diagnosis and treatment recently because of their unique physical and chemical properties. MoS2 can adsorb various biomolecules and drug molecules via covalent or non-covalent interactions because it is easy to modify and possess a high specific surface area, improving its tumor targeting and colloidal stability, as well as accuracy and sensitivity for detecting specific biomarkers. At the same time, in the near-infrared (NIR) window, MoS2 has excellent optical absorption and prominent photothermal conversion efficiency, which can achieve NIR-based phototherapy and NIR-responsive controlled drug-release. Significantly, the modified MoS2-nanocomposite can specifically respond to the tumor microenvironment, leading to drug accumulation in the tumor site increased, reducing its side effects on non-cancerous tissues, and improved therapeutic effect. In this review, we introduced the latest developments of MoS2-nanocomposites in cancer diagnosis and therapy, mainly focusing on biosensors, bioimaging, chemotherapy, phototherapy, microwave hyperthermia, and combination therapy. Furthermore, we also discuss the current challenges and prospects of MoS2-nanocomposites in cancer treatment.

Development and application of ultrasound contrast agents in biomedicine

With the rapid development of molecular imaging, ultrasound (US) medicine has evolved from traditional imaging diagnosis to integrated diagnosis and treatment at the molecular level. Ultrasound contrast agents (UCAs) play a crucial role in the integration of US diagnosis and treatment. As the micro-bubbles (MBs) in UCAs can enhance the cavitation effect and promote the biological effect of US, UCAs have also been studied in the fields of US thrombolysis, mediated gene transfer, drug delivery, and high intensity focused US. The application range of UCAs is expanding, and the value of their applications is improving. This paper reviews the development and application of UCAs in biomedicine in recent years, and the existing problems and prospects are pointed out.

Advances in Cancer Therapeutics: Conventional Thermal Therapy to Nanotechnology-Based Photothermal Therapy

In this review, advancement in cancer therapy that shows a transition from conventional thermal therapies to laser-based photothermal therapies is discussed. Laser-based photothermal therapies are gaining popularity in cancer therapeutics due to their overall outcomes. In photothermal therapy, light is converted into heat to destruct the various types of cancerous growth. The role of nanoparticles as a photothermal agent is emphasized in this review article. Magnetic, as well as non-magnetic, nanoparticles have been effectively used in the photothermal-based cancer therapies. The discussion includes a critical appraisal of in vitro and in vivo, as well as the latest clinical studies completed in this area. Plausible evidence suggests that photothermal therapy is a promising avenue in the treatment of cancer.

Distributed Sensing Network Enabled by High-Scattering MgO-Doped Optical Fibers for 3D Temperature Monitoring of Thermal Ablation in Liver Phantom

Thermal ablation is achieved by delivering heat directly to tissue through a minimally invasive applicator. The therapy requires a temperature control between 50-100 °C since the mortality of the tumor is directly connected with the thermal dosimetry. Existing temperature monitoring techniques have limitations such as single-point monitoring, require costly equipment, and expose patients to X-ray radiation. Therefore, it is important to explore an alternative sensing solution, which can accurately monitor temperature over the whole ablated region. The work aims to propose a distributed fiber optic sensor as a potential candidate for this application due to the small size, high resolution, bio-compatibility, and temperature sensitivity of the optical fibers. The working principle is based on spatial multiplexing of optical fibers to achieve 3D temperature monitoring. The multiplexing is achieved by high-scattering, nanoparticle-doped fibers as sensing fibers, which are spatially separated by lower-scattering level of single-mode fibers. The setup, consisting of twelve sensing fibers, monitors tissue of 16 mm × 16 mm × 25 mm in size exposed to a gold nanoparticle-mediated microwave ablation. The results provide real-time 3D thermal maps of the whole ablated region with a high resolution. The setup allows for identification of the asymmetry in the temperature distribution over the tissue and adjustment of the applicator to follow the allowed temperature limits.

Recent advances in innovative strategies for enhanced cancer photodynamic therapy

Photodynamic therapy (PDT), a non-invasive therapeutic modality, has received increasing attention owing to its high selectivity and limited side effects. Although significant clinical research progress has been made in PDT, the breadth and depth of its clinical application have not been fully realized due to the limitations such as inadequate light penetration depth, non-targeting photosensitizers (PSs), and tumor hypoxia. Consequently, numerous investigations put their emphasis on innovative strategies to overcome the aforementioned limitations and enhance the therapeutic effect of PDT. Herein, up-to-date advances in these innovative methods for PDT are summarized by introducing the design of PS systems, their working mechanisms and application examples. In addition, current challenges of these innovative strategies for clinical application, and future perspectives on further improvement of PDT are also discussed.

Three Birds with One Stone: Injectable CaC2 Nanobombs with Triple Effects for Minimally Invasive Tumor Chemical Ablation

Percutaneous chemical ablation (PCA) is the oldest and most established technique for treating small solid tumors in organs. It has been widely used in clinics even on an outpatient basis. However, compared with the emerging microwave or magnetic hyperthermal ablation, PCA is faced with relatively poor necrosis results and needs to repeat multiple sessions. Inspired by the three effects in the bomb's explosive process, we herein expect to combine calcium carbide (CaC₂) nanoparticles into the PCA technique to generate local explosion within tumor tissues, leading to three killing effects against tumors to further improve the ablation efficacy of PCA. Through an efficient wet milling procedure with poly(ethylene glycol), three kinds of nanobombs including CaC₂, calcium oxide (CaO), and calcium hydroxide (Ca(OH)₂) were fabricated, and they all exhibited desirable suspension stability. Among these nanobombs, in particular CaC₂ nanobombs showed a synergistic effect that the generation of ethyne gas bubbles could facilitate the most rapid diffusion of hyperthermia. Also, CaC₂ nanobombs offered the powerful ability to cause the sudden rise of local high temperature and pH value. According to the in vivo mice tumor excision trial, the tumors of 75% of cases that received CaC₂ treatment were destroyed and eradicated, exhibiting the excellent ablation ability of CaC₂ nanobombs against small solid tumors planted in mice.

PLGA-Based Drug Delivery Systems for Remotely Triggered Cancer Therapeutic and Diagnostic Applications

Intelligent drug delivery systems based on nanotechnology have been widely developed and investigated in the field of nanomedicine since they were able to maximize the therapeutic efficacy and minimize the undesirable adverse effects. Among a variety of organic or inorganic nanomaterials available to fabricate drug delivery systems (DDSs) for cancer therapy and diagnosis, poly(D,L-lactic-co-glycolic acid) (PLGA) has been extensively employed due to its biocompatibility and biodegradability. In this paper, we review the recent status of research on the application of PLGA-based drug delivery systems (DDSs) in remotely triggered cancer therapy and the strategies for tumor imaging provided by PLGA-based DDSs. We firstly discuss the employment of PLGA-based DDSs for remotely triggered cancer therapy, including photo-triggered, ultrasound-triggered, magnetic field-triggered, and radiofrequency-triggered cancer therapy. Photo-triggered cancer therapy involves photodynamic therapy (PDT), photothermal therapy (PTT), and photo-triggered chemotherapeutics release. Ultrasound-triggered cancer therapy involves high intensity focused ultrasound (HIFU) treatment, ultrasound-triggered chemotherapeutics release, and ultrasound-enhanced efficiency of gene transfection. The strategies which endows PLGA-based DDSs with imaging properties and the PLGA-based cancer theranostics are further discussed. Additionally, we also discuss the targeting strategies which provide PLGA-based DDSs with passive, active or magnetic tumor-targeting abilities. Numerous studies cited in our review demonstrate the great potential of PLGA-based DDSs as effective theranostic agent for cancer therapy and diagnosis.

Nano-Enhanced Drug Delivery and Therapeutic Ultrasound for Cancer Treatment and Beyond

While ultrasound is most widely known for its use in diagnostic imaging, the energy carried by ultrasound waves can be utilized to influence cell function and drug delivery. Consequently, our ability to use ultrasound energy at a given intensity unlocks the opportunity to use the ultrasound for therapeutic applications. Indeed, in the last decade ultrasound-based therapies have emerged with promising treatment modalities for several medical conditions. More recently, ultrasound in combination with nanomedicines, i.e., nanoparticles, has been shown to have substantial potential to enhance the efficacy of many treatments including cancer, Alzheimer disease or osteoarthritis. The concept of ultrasound combined with drug delivery is still in its infancy and more research is needed to unfold the mechanisms and interactions of ultrasound with different nanoparticles types and with various cell types. Here we present the state-of-art in ultrasound and ultrasound-assisted drug delivery with a particular focus on cancer treatments. Notably, this review discusses the application of high intensity focus ultrasound for non-invasive tumor ablation and immunomodulatory effects of ultrasound, as well as the efficacy of nanoparticle-enhanced ultrasound therapies for different medical conditions. Furthermore, this review presents safety considerations related to ultrasound technology and gives recommendations in the context of system design and operation.

Enhancement of Photodynamic Cancer Therapy by Physical and Chemical Factors

The viable use of photodynamic therapy (PDT) in cancer therapy has never been fully realized because of its undesirable effects on healthy tissues. Herein we summarize some physicochemical factors that can make PDT a more viable and effective option to provide future oncological patients with better-quality treatment options. These physicochemical factors include light sources, photosensitizer (PS) carriers, microwaves, electric fields, magnetic fields, and ultrasound. This Review is meant to provide current information pertaining to PDT use, including a discussion of in vitro and in vivo studies. Emphasis is placed on the physicochemical factors and their potential benefits in overcoming the difficulty in transitioning PDT into the medical field. Many advanced techniques, such as employing X-rays as a light source, using nanoparticle-loaded stem cells and bacteriophage bio-nanowires as a photosensitizer carrier, as well as integration with immunotherapy, are among the future directions.

Application of Nanoparticles and Nanomaterials in Thermal Ablation Therapy of Cancer

Cancer is one of the major health issues with increasing incidence worldwide. In spite of the existing conventional cancer treatment techniques, the cases of cancer diagnosis and death rates are rising year by year. Thus, new approaches are required to advance the traditional ways of cancer therapy. Currently, nanomedicine, employing nanoparticles and nanocomposites, offers great promise and new opportunities to increase the efficacy of cancer treatment in combination with thermal therapy. Nanomaterials can generate and specifically enhance the heating capacity at the tumor region due to optical and magnetic properties. The mentioned unique properties of nanomaterials allow inducing the heat and destroying the cancerous cells. This paper provides an overview of the utilization of nanoparticles and nanomaterials such as magnetic iron oxide nanoparticles, nanorods, nanoshells, nanocomposites, carbon nanotubes, and other nanoparticles in the thermal ablation of tumors, demonstrating their advantages over the conventional heating methods.

Nanoparticles and cancer therapy: Perspectives for application of nanoparticles in the treatment of cancers

Rapid growth in nanotechnology toward the development of nanomedicine agents holds massive promise to improve therapeutic approaches against cancer. Nanomedicine products represent an opportunity to achieve sophisticated targeting strategies and multifunctionality. Nowadays, nanoparticles (NPs) have multiple applications in different branches of science. In recent years, NPs have repetitively been reported to play a significant role in modern medicine. They have been analyzed for different clinical applications, such as drug carriers, gene delivery to tumors, and contrast agents in imaging. A wide range of nanomaterials based on organic, inorganic, lipid, or glycan compounds, as well as on synthetic polymers has been utilized for the development and improvement of new cancer therapeutics. In this study, we discuss the role of NPs in treating cancer among different drug delivery methods for cancer therapy.

Aggregation Behavior of Nanoparticle-Peptide Systems Affects Autophagy

The aggregation of nanoparticle colloidal dispersions in complex biological environments changes the nanoparticle properties, such as size and surface area, thus affecting the interaction of nanoparticles at the interface with cellular components and systems. We investigated the effect of nanoparticle aggregation on autophagy, the main catabolic pathway that mediates degradation of nanosized materials and that is activated in response to internalization of foreign nanosized materials. We used carboxylated polystyrene nanoparticles (100 nm) and altered the nanoparticle aggregation behavior through addition of a multidomain peptide, thus generating a set of nanoparticle-peptide mixtures with variable aggregation properties. Specifically, modulating the peptide concentration resulted in nanoparticle-peptide mixtures that are well dispersed extracellularly but aggregate upon cellular internalization. We monitored the effect of internalization of nanoparticle-peptide mixtures on a comprehensive set of markers of the autophagy pathway, ranging from transcriptional regulation to clearance of autophagic substrates. The nanoparticle-peptide mixtures were found to activate the transcription factor EB, a master regulator of autophagy and lysosomal biogenesis. We also found that intracellular aggregation of nanoparticle colloidal dispersions causes blockage of autophagic flux. This study provides important insights on the effect of the aggregation properties of nanoparticles on cells and, particularly, on the main homeostatic pathway activated in response to nanoparticle internalization. These results also point to the need to control the colloidal stability of nanoparticle systems for a variety of biomedical applications.

Synthesis and Enhanced Cellular Uptake In Vitro of Anti-HER2 Multifunctional Gold Nanoparticles

Nanoparticle carriers offer the possibility of enhanced delivery of therapeutic payloads in tumor tissues due to tumor-selective accumulation through the enhanced permeability and retention effect (EPR). Gold nanoparticles (AuNP), in particular, possess highly appealing features for development as nanomedicines, such as biocompatibility, tunable optical properties and a remarkable ease of surface functionalization. Taking advantage of the latter, several strategies have been designed to increase treatment specificity of gold nanocarriers by attaching monoclonal antibodies on the surface, as a way to promote selective interactions with the targeted cells—an approach referred to as active-targeting. Here, we describe the synthesis of spherical gold nanoparticles surface-functionalized with an anti-HER2 antibody-drug conjugate (ADC) as an active targeting agent that carries a cytotoxic payload. In addition, we enhanced the intracellular delivery properties of the carrier by attaching a cell penetrating peptide to the active-targeted nanoparticles. We demonstrate that the antibody retains high receptor-affinity after the structural modifications performed for drug-conjugation and nanoparticle attachment. Furthermore, we show that antibody attachment increases cellular uptake in HER2 amplified cell lines selectively, and incorporation of the cell penetrating peptide leads to a further increase in cellular internalization. Nanoparticle-bound antibody-drug conjugates retain high antimitotic potency, which could contribute to a higher therapeutic index in high EPR tumors.

The Effects of Mobile Phone Radiofrequency Electromagnetic Fields on β-Amyloid-Induced Oxidative Stress in Human and Rat Primary Astrocytes

Amyloid beta peptide (Aβ) is implicated in the development of pathological reactions associated with Alzheimer's disease (AD), such as oxidative stress, neuro-inflammation and death of brain cells. Current pharmacological approaches to treat AD are not able to control the deposition of Aβ and suppression of Aβ-induced cellular response. There is a growing body of evidence that exposure to radiofrequency electromagnetic field (RF-EMF) causes a decrease of beta-amyloid deposition in the brains and provides cognitive benefits to Alzheimer's Tg mice. Herein, we investigated the effects of mobile phone radiofrequency EMF of 918 MHz on reactive oxygen species (ROS) formation, mitochondrial membrane potential (MMP), activity of NADPH-oxidase, and phosphorylation of p38MAPK and ERK1/2 kinases in human and rat primary astrocytes in the presence of Aβ₄₂ and H₂O₂. Our data demonstrate that EMF is able to reduce Aβ₄₂- and H₂O₂-induced cellular ROS, abrogate Aβ₄₂-induced production of mitochondrial ROS and the co-localization between the cytosolic (p47-phox) and membrane (gp91-phox) subunits of NADPH oxidase, while increasing MMP, and inhibiting H₂O₂-induced phosphorylation of p38MAPK and ERK1/2 in primary astrocytes. Yet, EMF was not able to modulate alterations in the phosphorylation state of the MAPKs triggered by Aβ₄₂. Our findings provide an insight into the mechanisms of cellular and molecular responses of astrocytes on RF-EMF exposure and indicate the therapeutic potential of RF-EMF for the treatment of Alzheimer's disease.

Lipid-Wrapped Upconversion Nanoconstruct/Photosensitizer Complex for Near-Infrared Light-Mediated Photodynamic Therapy

Photodynamic therapy (PDT) is a noninvasive medical technology that has been applied in cancer treatment where it is accessible by direct or endoscope-assisted light irradiation. To lower phototoxicity and increase tissue penetration depth of light, great effort has been focused on developing new sensitizers that can utilize red or near-infrared (NIR) light for the past decades. Lanthanide-doped upconversion nanoparticles (UCNPs) have a unique property to transduce NIR excitation light to UV-vis emission efficiently. This property allows some low-cost, low-toxicity, commercially available visible light sensitizers, which originally are not suitable for deep tissue PDT, to be activated by NIR light and have been reported extensively in the past few years. However, some issues still remain in the UCNP-assisted PDT platform such as colloidal stability, photosensitizer loading efficiency, and accessibility for targeting ligand installation, despite some advances in this direction. In this study, we designed a facile phospholipid-coated UCNP method to generate a highly colloidally stable nanoplatform that can effectively load a series of visible light sensitizers in the lipid layers. The loading stability and singlet oxygen generation efficiency of this sensitizer-loaded lipid-coated UCNP platform were investigated. We also have demonstrated the enhanced cellular uptake efficiency and tumor cell selectivity of this lipid-coated UCNP platform by changing the lipid dopant. On the basis of the evidence of our results, the lipid-complexed UCNP nanoparticles could serve as an effective photosensitizer carrier for NIR light-mediated PDT.

A repertoire of biomedical applications of noble metal nanoparticles

The emerging properties of noble metal nanoparticles are attracting huge interest from the translational scientific community. In this feature article, we highlight recent advances in the adaptation of noble metal nanomaterials and their biomedical applications in therapeutics, diagnostics and sensing.

Nanoparticle-Mediated Acoustic Cavitation Enables High Intensity Focused Ultrasound Ablation Without Tissue Heating

While thermal ablation of various solid tumors has been demonstrated using high intensity focused ultrasound (HIFU), the therapeutic outcomes of this technique are still unsatisfactory because of common recurrence of thermally ablated cancers and treatment side effects due to the high ultrasound intensity and acoustic pressure requirements. More precise ablation of tumors can be achieved by generating cavitating bubbles in the tissue using shorter pulses with higher acoustic pressures, which induce mechanical damage rather than thermal. However, it has remained as a challenge to safely deliver the acoustic pressures required for mechanical ablation of solid tumors. Here, we report a method to achieve mechanical ablation at lower acoustic pressures by utilizing phospholipid-stabilized hydrophobic mesoporous silica nanoparticles (PL-hMSN). The PL-hMSNs act as seeds for nucleation of cavitation events and thus significantly reduce the peak negative pressures and spatial-average temporal-average HIFU intensities needed to achieve mechanical ablation. Substantial mechanical damage was observed in the red blood cell or tumor spheroid containing tissue mimicking phantoms at PL-hMSN concentrations as low as 10 μg mL^-1, after only 5 s of HIFU treatment with peak negative pressures ∼11 MPa and duty cycles ∼0.01%. Even the application of HIFU (peak negative pressure of 16.8 MPa and duty cycle of 0.017%) for 1 min in the presence of PL-hMSN (200 μg mL^-1) did not cause any detectable temperature increase in tissue-mimicking phantoms. In addition, the mechanical effects of cavitation promoted by PL-hMSNs were observed up to 0.5 mm from the center of the cavitation events. This method may thus also improve delivery of therapeutics or nanoparticles to tumor environments with limited macromolecular transport.

The Influence of Dynamic Tissue Properties on HIFU Hyperthermia: A Numerical Simulation Study

Accurate temperature and thermal dose prediction are crucial to high-intensity focused ultrasound (HIFU) hyperthermia, which has been used successfully for the non-invasive treatment of solid tumors. For the conventional method of prediction, the tissue properties are usually set as constants. However, the temperature rise induced by HIFU irradiation in tissues will cause changes in the tissue properties that in turn affect the acoustic and temperature field. Herein, an acoustic–thermal coupling model is presented to predict the temperature and thermal damage zone in tissue in terms of the Westervelt equation and Pennes bioheat transfer equation, and the individual influence of each dynamic tissue property and the joint effect of all of the dynamic tissue properties are studied. The simulation results show that the dynamic acoustic absorption coefficient has the greatest influence on the temperature and thermal damage zone among all of the individual dynamic tissue properties. In addition, compared with the conventional method, the dynamic acoustic absorption coefficient leads to a higher focal temperature and a larger thermal damage zone; on the contrary, the dynamic blood perfusion leads to a lower focal temperature and a smaller thermal damage zone. Moreover, the conventional method underestimates the focal temperature and the thermal damage zone, compared with the simulation that was performed using all of the dynamic tissue properties. The results of this study will be helpful to guide the doctors to develop more accurate clinical protocols for HIFU treatment planning.

Roles of Textural and Surface Properties of Nanoparticles in Ultrasound-Responsive Systems

Acoustic inertial cavitation (IC) is a crucial phenomenon for many ultrasound (US)-related applications. This study aimed to investigate the roles of textural and surface properties of NPs in IC generation by combining typical IC detection methods with various types of silica model NPs. Acoustic passive cavitation detection, optical high-speed photography, and US imaging have been used to quantify IC activities (referred to as the IC dose, ICD) and describe the physical characteristics of IC activities from NPs. The results showed that the ICDs from NPs were positively correlated to their surface hydrophobicity and that their external surface hydrophobicity plays a much more crucial role than do the textural properties. The high-speed photography revealed that the sizes of IC-generated bubbles from superhydrophobic NPs ranged from 20-40 μm at 4-6 MPa and collapsed in several microseconds. Bubble clouds monitored with US imaging showed that IC from NPs was consistent with the surface hydrophobicity. The simulation results based on the crevice model of cavitation nuclei correlated well with the experimental results. This study has demonstrated that the surface property, instead of the textural property, of NPs dominated the IC generation, and surface nanobubbles adsorbed on the NP surface have been proposed to be cavitation nuclei.

MoS2 nanosheets encapsulated in sodium alginate microcapsules as microwave embolization agents for large orthotopic transplantation tumor therapy

In recent years, it is prevalent to treat various kinds of the tumors through microwave ablation method. However, it is still very difficult to ablate large tumors by the traditional microwave ablation therapy. In this work, an effective microwave embolization agent designed by encapsulating molybdenum sulfide nanosheets in the sodium alginate microcapsules, denoted as MSMCs, was prepared for the effective therapy of large tumor. The toxicity evaluation showed that MSMC had a good biocompatibility in vitro. The in vitro and in vivo experiments demonstrated that the MSMC was an excellent embolic and microwave susceptible agent that could be used for dual-enhanced microwave ablation therapy. As such, the MSMC showed excellent tumor therapeutic effect with 5 times larger ablation zone observed by magnetic resonance (MR) imaging than the microwave alone after 3 days treating. Besides, the tumor is nearly completely ablated and can not be recurrent due to the persistent hyperthermia. Moreover, MSMCs have a good biocompatibility and can be degraded and cleared from the body. It is believed that the MSMC is demonstrated to be a promising multifunctional theranostic agent used for treating the larger tumor via the synergistic therapy of enhanced microwave ablation and transcatheter arterial embolization (TAE).

Diels Alder-mediated release of gemcitabine from hybrid nanoparticles for enhanced pancreatic cancer therapy

Hybrid nanoparticles (HNPs) have shown huge potential as drug delivery vehicles for pancreatic cancer. Currently, the first line treatment, gemcitabine, is only effective in 23.8% of patients. To improve this, a thermally activated system was developed by introducing a linker between HNPs and gemcitabine. Whereby, heat generation resulting from laser irradiation of the HNPs promoted linker breakdown resulting in prodrug liberation. In vitro evaluation in pancreatic adenocarcinoma cells, showed the prodrug was 4.3 times less cytotoxic than gemcitabine, but exhibited 11-fold improvement in cellular uptake. Heat activation of the formulation led to a 56% rise in cytotoxicity causing it to outperform gemcitabine by 26%. In vivo the formulation outperformed free gemcitabine with a 62% reduction in tumor weight in pancreatic xenografts. This HNP formulation is the first of its kind and has displayed superior anti-cancer activity as compared to the current first line drug gemcitabine after heat mediated controlled release.

Phospholipid Capped Mesoporous Nanoparticles for Targeted High Intensity Focused Ultrasound Ablation

The mechanical effects of cavitation can be effective for therapy but difficult to control, thus potentially leading to off-target side effects in patients. While administration of ultrasound active agents such as fluorocarbon microbubbles and nanodroplets can locally enhance the effects of high intensity focused ultrasound (HIFU), it has been challenging to prepare ultrasound active agents that are small and stable enough to accumulate in tumors and internalize into cancer cells. Here, this paper reports the synthesis of 100 nm nanoparticle ultrasound agents based on phospholipid-coated, mesoporous, hydrophobically functionalized silica nanoparticles that can internalize into cancer cells and remain acoustically active. The ultrasound agents produce bubbles when subjected to short HIFU pulses (≈6 µs) with peak negative pressure as low as ≈7 MPa and at particle concentrations down to 12.5 µg mL-1 (7 × 109 particles mL-1 ). Importantly, ultrasound agents are effectively uptaken by cancer cells without cytotoxic effects, but HIFU insonation causes destruction of the cells by the acoustically generated bubbles, as demonstrated by (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) and lactate dehydrogenase assays and flow cytometry. Finally, it is showed that the HIFU dose required to effectively eliminate cancer cells in the presence of ultrasound agents causes only a small temperature increase of ≈3.5 °C.

Multicomponent nanocrystals with anti-Stokes luminescence as contrast agents for modern imaging techniques

Lanthanide-doped upconversion nanoparticles (UCNPs) have recently attracted great attention in theranostics due to their exceptional optical and physicochemical properties, which enable the design of a novel UCNP-based nanoplatform for luminescent imaging, temperature mapping, sensing, and therapy. In addition, UCNPs are considered to be ideal building blocks for development of multimodal probes for cells and whole body imaging, exploiting simple variation of host matrix, dopant ions, and surface chemistry. Modalities responsible for magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography (PET)/single-photon emission computed tomography (SPECT) are embedded in a single UC nanocrystal, providing integrating effect over any modality alone in terms of the efficiency and sensitivity for clinical innovative diagnosis through multimodal bioimaging. In particular, we demonstrate applications of UCNPs as a new nanoplatform for optical and multimodal cancer imaging in vitro and in vivo and extend discussions to delivery of UCNP-based therapeutic agents for photodynamic and photothermal cancer treatments.