Nanoparticles of Titanium and Zinc Oxides as Novel Agents in Tumor Treatment: a Review

Zinc nanoparticles coated with doxorubicin-conjugated alginate as a radiation sensitizer in triple-negative breast cancer cells

The main treatment modalities for breast cancer include surgery, chemotherapy, and radiotherapy, and each treatment will bring different side effects. Design and synthesizing a novel nanostructure for chemo-radiotherapy has been proposed as an effective method in consideration to enhance the drug efficiency as well as improve the effect of radiotherapy. This study aimed to synthesize zinc nanoparticles (ZnNPs) coated with alginate conjugated with Doxorubicin (Dox) drug and investigate its effects along with X-irradiation on MDA-MB-231 triple-negative breast cancer cell line. ZnNPs coated with alginate were synthesized and conjugated to Dox by covalent bonding and characterized using various physicochemical tests. A hemolysis test was used to assess blood biocompatibility. The radiosensitization properties and anti-cancer effects of the synthesized nanostructures were tested by cell uptake, cell viability, apoptosis, cell cycle, and scratch assays with and without radiation exposure. The physicochemical characterization results showed that the synthesis of nanostructures was successfully carried out. The obtained results from the cell uptake assay showed the effective absorption of nanostructures by the cells. The Zn@Alg-Dox NPs significantly reduced cell growth, increased apoptosis, inhibited cell migration, and led to the arrest of different cell cycle phases in both conditions with and without X-ray exposure. Coating ZnNPs with alginate and Doxorubicin conjugation leads to an increase the radiation sensitivity in radiotherapy as well as therapeutic efficiency. Therefore, Zn@Alg-Dox NPs can be used as radiosensitizing nanomedicine for in vivo studies in the future.

Ultrasound-augmented cancer immunotherapy

Cancer is a growing worldwide health problem with the most broadly studied treatments, in which immunotherapy has made notable advancements in recent years. However, innumerable patients have presented a poor response to immunotherapy and simultaneously experienced immune-related adverse events, with failed therapeutic results and increased mortality rates. Consequently, it is crucial to develop alternate tactics to boost therapeutic effects without producing negative side effects. Ultrasound is considered to possess significant therapeutic potential in the antitumor field because of its inherent characteristics, including cavitation, pyrolysis, and sonoporation. Herein, this timely review presents the comprehensive and systematic research progress of ultrasound-enhanced cancer immunotherapy, focusing on the various ultrasound-related mechanisms and strategies. Moreover, this review summarizes the design and application of current sonosensitizers based on sonodynamic therapy, with an attempt to provide guidance on new directions for future cancer therapy.

Albumin-coated green-synthesized zinc oxide nanoflowers inhibit skin melanoma cells growth via intra-cellular oxidative stress

Zinc oxide (ZnO) has attracted a substantial interest in cancer research owing to their promising utility in cancer imaging and therapy. This study aimed to synthesized ZnO nanoflowers coated with albumin to actively target and the inhibit skin melanoma cells. We synthesized bovine serum albumin (BSA)-coated ZnO nanoflowers (BSA@ZnO NFs) and evaluated it's in vitro and in vivo therapeutic efficacy for skin cancer cells. BSA@ZnO NFs were prepared via single-step reduction method in the presence of plant extract (Heliotropium indicum) act as a capping agent, and further the successful fabrication was established by various physico-chemical characterizations, such as scanning electron microscopy (SEM), Fourier transform infra-red (FT-IR) spectroscopy, and x-rays diffraction (XRD) analysis. The fabricated BSA@ZnO NFs appeared flower like with multiple cone-shaped wings and average hydration size of 220.8 ± 12.6 nm. Further, BSA@ZnO NFs showed enhanced cellular uptake and cytocidal effects against skin cancer cells by inhibiting their growth via oxidative stress compared uncoated ZnO NFs. Moreover, BSA@ZnO NFs showed enhance biosafety, blood circulation time, tumor accumulation and in vivo tumor growth inhibition compared to ZnO NFs. In short, our findings suggesting BSA@ZnO NFs as a promising candidate for various types of cancer treatment along with chemotherapy.

Brucine Entrapped Titanium Oxide Nanoparticle for Anticancer Treatment: An In Vitro Study

Backgroundand Objective. The public's health has been seriously threatened by cervical cancer during recent times. In terms of newly diagnosed cases worldwide, it ranks as the ninth most prevalent malignancy. Multiple investigations have proven that nanoparticles can effectively combat cancer due to their small dimensions and extensive surface area. In the meantime, bioactive compounds which are biocompatible are being loaded onto nanoparticles to promote cancer therapy. The current study investigates the anticancerous potential of Brucine-entrapped titanium oxide nanoparticles (TiO2 NPs) in cervical cancer cell line (HeLa). Materials and Methods. The physiochemical, structural, and morphological aspects of Brucine-entrapped TiO2 NPs were evaluated by UV-visible spectrophotometer, Fourier transform-infrared spectroscopy (FT-IR), dynamic light scattering (DLS), scanning electron microscopy (SEM), and energy dispersive X-ray (EDAX). The cytotoxic effect against the HeLa cell line was assessed using a tetrazolium-based colorimetric assay (MTT), a trypan blue exclusion (TBE) assay, phase contrast microscopic analysis, and a fluorescence assay including ROS and DAPI staining. Furthermore, estimation of antioxidant markers includes catalase (CAT), glutathione (GSH), and superoxide dismutase (SOD). Results. The UV spectrum at 266 nm revealed the formation of TiO NPs. The FT-IR peaks confirmed the effective entrapment of brucine with TiO2 NPs. The average size (100.0 nm) of Brucine-entrapped TiO2 NPs was revealed in DLS analysis. The micrograph of the SEM revealed the formation of ellipsoidal to tetragonal-shaped NPs. The Ti, O, and C signals were observed in EDAX. In MTT assay, Brucine-entrapped TiO2 NPs showed inhibition of cell proliferation in a dose-wise manner and IC50 was noticed at the concentration of 30 µg/mL. The percentage of viable cells gradually reduced in the trypan blue exclusion assay. The phase contrast microscopic analysis of Brucine-entrapped TiO2 NP-treated cells showed cell shrinkage, cell wall deterioration, and cell blebbing. The intracellular ROS level was increased in a dose-wise manner when compared to control cells in ROS staining. The condensed nuclei and apoptotic cells were increased in treated cells, as noted in DAPI staining. In treated cells, the antioxidant markers such as CAT, GSH, and SOD levels were substantially lower compared to the control cells. Conclusion. The synthesized Brucine entrapped TiO2 NPs exhibited remarkable anticancer activity against the HeLa cell line.

A Distinctive Insight into Inorganic Sonosensitizers: Design Principles and Application Domains

Sonodynamic therapy (SDT) as a promising non-invasive anti-tumor means features the preferable penetration depth, which nevertheless, usually can't work without sonosensitizers. Sonosensitizers produce reactive oxygen species (ROS) in the presence of ultrasound to directly kill tumor cells, and concurrently activate anti-tumor immunity especially after integration with tumor microenvironment (TME)-engineered nanobiotechnologies and combined therapy. Current sonosensitizers are classified into organic and inorganic ones, and current most reviews only cover organic sonosensitizers and highlighted their anti-tumor applications. However, there have few specific reviews that focus on inorganic sonosensitizers including their design principles, microenvironment regulation, etc. In this review, inorganic sonosensitizers are first classified according to their design rationales rather than composition, and the action rationales and underlying chemistry features are highlighted. Afterward, what and how TME is regulated based on the inorganic sonosensitizers-based SDT nanoplatform with an emphasis on the TME targets-engineered nanobiotechnologies are elucidated. Additionally, the combined therapy and their applications in non-cancer diseases are also outlined. Finally, the setbacks and challenges, and proposed the potential solutions and future directions is pointed out. This review provides a comprehensive and detailed horizon on inorganic sonosensitizers, and will arouse more attentions on SDT.

Progress of Piezoelectric Semiconductor Nanomaterials in Sonodynamic Cancer Therapy

Sonodynamic therapy is an emerging noninvasive tumor treatment method that utilizes ultrasound to stimulate sonosensitizers to produce a large amount of reactive oxygen species, inducing tumor cell death. Though sonodynamic therapy has very promising prospects in cancer treatment, the application of early organic sonosensitizers has been limited in efficacy due to the high blood clearance-rate, poor water solubility, and low stability. Inorganic sonosensitizers have thus been developed, among which piezoelectric semiconductor materials have received increasing attention in sonodynamic therapy due to their piezoelectric properties and strong stability. In this review, we summarized the designs, principles, modification strategies, and applications of several commonly used piezoelectric materials in sonodynamic therapy and prospected the future clinical applications for piezoelectric semiconductor materials in sonodynamic therapy.

Oxygen-Independent Synchronized ROS Generation and Hypoxia Prodrug Activation with Z-Scheme Heterostructure Sonosensitizer

Combination therapy has emerged as a promising approach for effective tumor treatment. However, the combination of sonodynamic therapy (SDT) and hypoxia-activated prodrugs (HAPs) has not been explored due to the contradictory requirement of oxygen (O2 ) for reactive oxygen species (ROS) generation and the necessity to avoid O2 for the activation of HAPs. In this study, this challenge is addressed by developing BiOCl-Au-Ag2 S Z-scheme heterostructure nanoparticles loaded with tirapazamine (TPZ) to achieve O2 -independent therapy. These nanoparticles demonstrate efficient electron-hole separation under ultrasound irradiation while maintaining a high redox potential. The generated holes react with water to efficiently produce hydroxyl radicals, while the electrons autonomously activate TPZ, negating the need for O2 . In vitro and in vivo assessments validate the effective tumor elimination by these Z-scheme nanoparticles without disrupting the hypoxic environment. This innovative design overcomes the limitations associated with O2 requirement in SDT and introduces a novel strategy for HAP activation and synergistic therapy between ROS and HAPs-based therapy.

Efficient sonochemical catalytic degradation of tetracycline using TiO2 fractured nanoshells

Overexposure to antibiotics originating in wastewater has profound environmental and health implications. Conventional treatment methods are not fully effective in removing certain antibiotics, such as the commonly used antibiotic, tetracycline, leading to its accumulation in water catchments. Alternative antibiotic removal strategies are garnering attention, including sonocatalytic oxidative processes. In this work, we investigated the degradation of tetracycline using a combination of TiO2 fractured nanoshells (TFNs) and an advanced sonochemical reactor design. The study encompassed an examination of multiple process parameters to understand their effects on the degradation of tetracycline. These included tetracycline adsorption on TFNs, reaction time, initial tetracycline concentration, solvent pH, acoustic pressure amplitude, number of acoustic cycles, catalyst dosage, TFNs' reusability, and the impact of adjuvants such as light and H2O2. Though TFNs adsorbed tetracycline, the addition of ultrasound was able to degrade tetracycline completely (with 100% degradation) within six minutes. Under the optimal operating conditions, the proposed sonocatalytic system consumed 80% less energy compared to the values reported in recently published sonocatalytic research. It also had the lowest CO2 footprint when compared to the other sono-/photo-based technologies. This study suggests that optimizing the reaction system and operating the reaction under low power and at a lower duty cycle are effective in achieving efficient cavitation for sonocatalytic reactions.

Prospects of nanoparticle-based radioenhancement for radiotherapy

Radiotherapy is a key pillar of solid cancer treatment. Despite a high level of conformal dose deposition, radiotherapy is limited due to co-irradiation of organs at risk and subsequent normal tissue toxicities. Nanotechnology offers an attractive opportunity for increasing the efficacy and safety of cancer radiotherapy. Leveraging the freedom of design and the growing synthetic capabilities of the nanomaterial-community, a variety of engineered nanomaterials have been designed and investigated as radiosensitizers or radioenhancers. While research so far has been primarily focused on gold nanoparticles and other high atomic number materials to increase the absorption cross section of tumor tissue, recent studies are challenging the traditional concept of high-Z nanoparticle radioenhancers and highlight the importance of catalytic activity. This review provides a concise overview on the knowledge of nanoparticle radioenhancement mechanisms and their quantification. It critically discusses potential radioenhancer candidate materials and general design criteria for different radiation therapy modalities, and concludes with research priorities in order to advance the development of nanomaterials, to enhance the efficacy of radiotherapy and to increase at the same time the therapeutic window.

Free zinc ions, as a major factor of ZnONP toxicity, disrupts free radical homeostasis in CCRF-CEM cells

Nanotechnology has become a ubiquitous part of our everyday life. Besides the already-known nanoparticles (NPs), plenty of new nanomaterials are being synthesized every day. Here, we explain the mechanism of the zinc oxide nanoparticles (ZnONPs) cytotoxicity in a cellular model of acute lymphoblastic leukaemia (CCRF-CEM). To do so, we investigated both possible hypotheses about the ZnONPs mechanism of toxicity: a free zinc ions release and/or reactive oxygen species (ROS) generation. Presented here results show that: Our results support the hypothesis that the mechanism of ZnONPs cytotoxicity is based on the release of free zinc ions. Nevertheless, both previously quoted hypotheses incompletely described the mechanism of action of ZnONPs. In this paper, we show that the mechanism of cytotoxicity of ZnONPs is based on the induction of reductive stress in CCRF-CEM cells, which is caused by free zinc ions released from ZnONPs. Therefore, the increase of oxidative stress markers is most likely a secondary response of the cells towards the Zn2+. These results provide a crucial expansion of the zinc ion hypothesis and thus explain the biphasic cellular response of CCRF-CEM cells treated with ZnONPs.

Inorganic Sonosensitizers for Sonodynamic Therapy in Cancer Treatment

The rapid development of nanomedicine and nanobiotechnology has allowed the emergence of various therapeutic modalities with excellent therapeutic efficiency and biosafety, among which, the sonodynamic therapy (SDT), a combination of low-intensity ultrasound and sonosensitizers, is emerging as a promising noninvasive treatment modality for cancer treatment due to its deeper penetration, good patient compliance, and minimal damage to normal tissue. The sonosensitizers are indispensable components in the SDT process because their structure and physicochemical properties are decisive for therapeutic efficacy. Compared to the conventional and mostly studied organic sonosensitizers, inorganic sonosensitizers (noble metal-based, transition metal-based, carbon-based, and silicon-based sonosensitizers) display excellent stability, controllable morphology, and multifunctionality, which greatly expand their application in SDT. In this review, the possible mechanisms of SDT including the cavitation effect and reactive oxygen species generation are briefly discussed. Then, the recent advances in inorganic sonosensitizers are systematically summarized and their formulations and antitumor effects, particularly highlighting the strategies for optimizing the therapeutic efficiency, are outlined. The challenges and future perspectives for developing state-of-the-art sonosensitizers are also discussed. It is expected that this review will shed some light on future screening of decent inorganic sonosensitizers for SDT.

Hybrid nanomaterial composed of chitosan, curcumin, ZnO and TiO2 for antibacterial therapies

Metal nanoparticles have been tremendously utilised, such as; antibacterial and anticancer agents. Although metal nanoparticles exhibits antibacterial and anticancer activity, but the drawback of toxicity on normal cells limits their clinical applications. Therefore, improving the bioactivity of hybrid nanomaterials (HNMs) and minimizing toxicity is of paramount importance for biomedical applications. Herein, a facile and simple double precipitation method was used to develop biocompatible and multifunctional HNM from antimicrobial chitosan, curcumin, ZnO and TiO₂. In HNM, biomolecules chitosan and curcumin were used to control the toxicity of ZnO and TiO₂ and improve their biocidal properties. The cytotxicological properties of the HNM was studied against human breast cancer (MDA-MB-231) and fibroblast (L929) cell lines. The antimicrobial activity of the HNM was examined against Escherichia coli and Staphylococcus aureus bacteria, via the well-diffusion method. In addition, the antioxidant property was evaluated by the radical scavenging method. These findings actively, support the ZTCC HNMs potential, as an innovative biocidal agent for applications in the clinical and healthcare sectors.

ROS-generating alginate-coated gold nanorods as biocompatible nanosonosensitisers for effective sonodynamic therapy of cancer

Sonodynamic therapy (SDT) emerges as a promising non-invasive alternative for eradicating malignant tumours. However, its therapeutic efficacy remains limited due to the lack of sonosensitisers with high potency and biosafety. Previously, gold nanorods (AuNRs) have been extensively studied for their applications in photodynamic or photothermal cancer therapy, but their sonosensitising properties are largely unexplored. Here, we reported the applicability of alginate-coated AuNRs (AuNRs^ALG) with improved biocompatibility profiles as promising nanosonosensitisers for SDT for the first time. AuNRs^ALG were found stable under ultrasound irradiation (1.0 W/cm², 5 min) and maintained structural integrity for 3 cycles of irradiation. The exposure of the AuNRs^ALG to ultrasound irradiation (1.0 W/cm², 5 min) was shown to enhance the cavitation effect significantly and generate a 3 to 8-fold higher amount of singlet oxygen (¹O₂) than other reported commercial titanium dioxide nanosonosensitisers. AuNRs^ALG exerted dose-dependent sonotoxicity on human MDA-MB-231 breast cancer cells in vitro, with ∼ 81% cancer cell killing efficacy at a sub-nanomolar level (IC₅₀ was 0.68 nM) predominantly through apoptosis. The protein expression analysis showed significant DNA damage and downregulation of anti-apoptotic Bcl-2, suggesting AuNRs^ALG induced cell death through the mitochondrial pathway. The addition of mannitol, a reactive oxygen species (ROS) scavenger, inhibited cancer-killing effect of AuNRs^ALG-mediated SDT, further verifying that the sonotoxicity of AuNRs^ALG is driven by the production of ROS. Overall, these results highlight the potential application of AuNRs^ALG as an effective nanosonosensitising agent in clinical settings.

Perovskite-Type Manganese Vanadate Sonosensitizers with Biodegradability for Enhanced Sonodynamic Therapy of Cancer

Sonodynamic therapy (SDT) has attracted intensive attention, but is still hindered by low sonosensitization and non-biodegradability of the traditional sonosensitizers. Herein, perovskite-type manganese vanadate (MnVO₃ ) sonosensitizers integrating high reactive oxide species (ROS) production efficiency and appropriate bio-degradability are developed for enhanced SDT. Taking advantage of the intrinsic properties of perovskites such as narrow bandgap and substantial oxygen vacancies, MnVO₃ shows a facile ultrasound (US)-triggered electrons-holes separation and restrained recombination, thus enhancing the ROS quantum yield in SDT. Furthermore, MnVO₃ exhibits a considerable chemodynamic therapy (CDT) effect under the acidic condition probably owing to the presence of manganese and vanadium ions. Due to the presence of high-valent vanadium, MnVO₃ can also eliminate glutathione (GSH) within the tumor microenvironment, which synergistically amplifies the efficacy of SDT and CDT. Importantly, the perovskite structure bestows MnVO₃ with superior biodegradability, which alleviates the long-term presence of residues in metabolic organs after therapeutic actions. Based on these characteristics, US-assisted MnVO₃ achieves an excellent antitumor outcome along with low systemic toxicity. Overall, perovskite-type MnVO₃ may be promising sonosensitizers for highly efficient and safe treatment of cancer. The work attempts to explore the potential utility of perovskites in the design of degradable sonosensitizers.

Functional bioinspired nanocomposites for anticancer activity with generation of reactive oxygen species

Cancer is a debilitating and deadly disease caused by the uncontrolled growth of aberrant cell populations. This disease cannot always be controlled with traditional therapies and medicines. Different medicines are being used for this purpose, however these medicines have their side effects and are harmful to healthy cells. A better way to cure cancer disease is by limiting the agglomeration of cancer cells, minimizing their growth and their population by destroying these harmful cells. This could be achieved by controlling the function of mitochondria and DNA in cancer cells with the use of biocompatible materials with tuneable physical properties. Accordingly, research is ongoing as to the use of nanomaterials and nanotechnology in medicine. Zinc oxide semiconductor nanoparticles have displayed good anticancer behaviour. They have unique properties such as biocompatibility, good stability, and are environmentally friendly. Owing to these characteristics, they are focused on biological applications such as drug delivery and cancer therapy. In the present research work, zinc oxide, titanium dioxide nanoparticles and titanium oxide-zinc oxide nanocomposites were successfully trailed for anti-cancer activity. Pure zinc oxide nanoparticles (ZnO NPs), titanium dioxide nanoparticles (TiO₂ NPs) and their nanocomposites (TiO₂+ZnO NPs) were prepared by the co-precipitation technique. The structural properties were investigated by X-ray diffraction, which confirmed the Wurtzite structure of pure ZnO NPs. The morphology of the NPs was checked by scanning electron microscopy. For incident light having a higher energy band gap of nanomaterials, the electrons are excited to the conduction band and these electrons generate reactive oxygen species (ROS). The efficacy of these nanomaterials was checked by exposing the NPs to the human liver cancer cell HepG2. The MTT assay describes anticancer activity via cell viability. The cell viability of composites was observed to be greater than pure ZnO NPs. Their results showed that the structure of ZnO NPs remains the same with composites of TiO₂ NPs, but the band gap of the composite was intermediate for individual samples. It also showed that the anticancer activity of composites was also less than pure ZnO NPs which is due to the reduction of ROS generation. This is observed that nanocomposites of ZnO and TiO₂ could be effective in the development of a treatment of human liver cancer cells.

Phytochemical and physiological reactions of feverfew (Tanacetum parthenium (L.) Schultz Bip) to TiO2 nanoparticles

Nanomaterials can be used as elicitors for improving the biosynthesis of secondary metabolites in medicinal plants. The present study was conducted to assay the titanium dioxide-nanoparticles (TiO₂-NPs) effects on feverfew (Tanacetum parthenium) as an anti-cancer plant. The study showed that TiO₂-NPs application increased the amounts of the main compounds and oxygenated monoterpene in essential oils, thereby causing an improvement in the quantity and quality of the essential oils compared to control. The highest effect was related to 1500 ppm TiO₂-NPs concentration. Regarding parthenolide, TiO₂-NPs had no positive effect on parthenolide content and the highest content was observed in control. Increasing the concentrations over 1500 ppm resulted in a decrease in chlorophyll content, capitule diameter, flower yield, and harvest index compared to other concentrations and control. Additionally, the results indicated that TiO₂-NPs foliar spray reduced flower number, biological yield, fresh weight, and dry weights compared with untreated plants. The increase in quality and content of essential oil and lack of increase in parthenolide content, and reproductive and vegetative characteristics showed that TiO₂-NPs mainly affected the content and composition of essential oil. Totally, the application of TiO2-NPs in terms of positive effect on the yield and metabolites (without damaging biological effects) can be recommended and followed up to the concentration of 1000 ppm. Overall, the results indicated that improving the synthesis of valuable medicinal metabolites using TiO₂-NPs has promising results depending on the type of species, concentration used and target metabolites.

Efficacy of Nanoparticles in dose enhancement with high dose rate of Iridium-192 and Cobalt-60 radionuclide sources in the Treatment of Cancer: A systematic review

ABSTRACTS

A key challenge in radiation therapy is to maximize the radiation dose to cancer cells while minimizing damage to healthy tissues. In recent years, the introduction of remote after-loading technology such as high-dose-rate (HDR) brachytherapy becomes the safest and more precise way of radiation delivery compared to classical low-dose-rate (LDR) brachytherapy. However, the axially symmetric dose distribution of HDR with single channel cylindrical applicator, the physical "dead-space" with multichannel applicators, and shielding material heterogeneities are the main challenges of HDR brachytherapy. Thus, this review aimed to quantitatively evaluate the dose enhancement factor (DEF) produced by high atomic number nanoparticles (NPs) which increases the interaction probability of photons mainly through the photoelectric effect induced in the great number of atoms contained in each nanoparticle. The NPs loaded to the target volume create a local intensification effect on the target tissue that allows imparting the prescribed therapeutic dose using lower fluxes of irradiation and spare the surrounding healthy tissues. An electronic database such as PubMed/Medline, Embase, Scopus, and Google Scholar was searched to retrieve the required articles. Unpublished articles were also reached by hand from available sources. The dose is increased using the high atomic number of nanoparticle elements under the high dose iridium radionuclide whereas the cobalt-60 radionuclide source did not. However, much work is required to determine the dose distribution outside the target organ or tumor to spare the surrounding healthy tissues for the iridium source and make compressive work to have more data for the cobalt source.

Synergistic chemotherapy and phototherapy based on red blood cell biomimetic nanomaterials

Novel drug delivery systems (DDSs) have become the mainstay of research in targeted cancer therapy. By combining different therapeutic strategies, potential DDSs and synergistic treatment approaches are needed to effectively deal with evolving drug resistance and the adverse effects of cancer. Nowadays, developing and optimizing human cell-based DDSs has become a new research strategy. Among them, red blood cells can be used as DDSs as they significantly enhance the pharmacokinetics of the transported drug cargo. Phototherapy, as a novel adjuvant in cancer treatment, can be divided into photodynamic therapy and photothermal therapy. Phototherapy using erythropoietic nanocarriers to mimic the unique properties of erythrocytes and overcome the limitations of existing DDSs shows excellent prospects in clinical settings. This review provides an overview of the development of photosensitizers and research on bio-nano-delivery systems based on erythrocytes and erythrocyte membranes that are used in achieving synergistic outcomes during phototherapy/chemotherapy.

The promising interplay between sonodynamic therapy and nanomedicine

Sonodynamic therapy (SDT) is a non-invasive approach for cancer treatment in which chemical compounds, named sonosensitizers, are activated by non-thermal ultrasound (US), able to deeply penetrate into the tissues. Despite increasing interest, the underlying mechanisms by which US triggers the sonosensitizer therapeutic activity are not yet clearly elucidate, slowing down SDT clinical application. In this review we will discuss the main mechanisms involved in SDT with particular attention to the sonosensitizers involved for each described mechanism, in order to highlight how much important are the physicochemical properties of the sonosensitizers and their cellular localization to predict their bioeffects. Moreover, we will also focus our attention on the pivotal role of nanomedicine providing the sonodynamic anticancer approach with the ability to shape US-responsive agents to enhance specific sonodynamic effects as the sonoluminescence-mediated anticancer effects. Indeed, SDT is one of the biomedical fields that has significantly improved in recent years due to the increased knowledge of nanosized materials. The shift of the nanosystem from a delivery system for a therapeutic agent to a therapeutic agent in itself represents a real breakthrough in the development of SDT. In doing so, we have also highlighted potential areas in this field, where substantial improvements may provide a valid SDT implementation as a cancer therapy.

Beneficial and toxicological aspects of zinc oxide nanoparticles in animals

Nanotechnology is a far‐reaching technology with tremendous applications in various aspects, including general medicine, veterinary medicine, agriculture, aquaculture, and food production. Nanomaterials have exceptional physicochemical characteristics, including increased intestinal absorption, biodistribution, bioavailability, and improved antimicrobial and catalytic properties. Although nanotechnology is gaining ground in animal management, husbandry, and production, its wide use is still hampered by occasional toxicity and side effects. Zinc oxide nanoparticles (ZnO‐NPs) have long been utilized in animal production, aquaculture, and pet animal medicine. However, the use ZnO‐NPs in animals has been associated with reports of toxicity and side effects. ZnO‐NPs may have shown numerous beneficial effects in animals; its use must be regulated with care to avoid unwanted consequences. Thus, this review emphasizes the usage of ZnO‐NPs in animal production and laboratory animals and the potential side effects associated with the use of nanoparticles as a feed supplement and therapeutic compound.

Rational design of ZnO-zeolite imidazole hybrid nanoparticles with reduced charge recombination for enhanced photocatalysis

Semiconducting zinc oxide nanoparticles (ZnO NPs) hold great potential as photocatalysts in wastewater treatment because of their favorable bandgap and cost-effectiveness. Unfortunately, ZnO NPs usually show rapid charge recombination that limits their photocatalytic efficacy significantly. Herein, we report a facile way of modifying ZnO NPs with zeolite imidazole framework-8 (ZIF8). A synergy between the two components may tackle the drawback of fast charge recombination for pristine ZnO NPs. Improved performance of photocatalytic degradation of methylene blue (MB) is confirmed by comparing with pristine ZnO and ZIF8 as the catalysts. The ZIF8 in the composite serves as a trap for photogenerated electrons, thus reducing the rate of charge recombination to enhance the photocatalysis rate. In addition, the hybridization process suppresses the aggregation of ZnO NPs, providing a large surface area and a greater number of active sites. Moreover, a small shift in the absorption band of ZnO@ZIF8 (10) NPs towards higher wavelength, also witnessed a little contribution towards enhanced photocatalytic properties. Mechanistic studies of the photocatalytic process of MB using ZnO@ZIF8 NPs catalyst reveal that hydroxyl radicals are the major reactive oxygen species. The facile hybridization of ZnO with ZIF8 provides a strategy for developing new photocatalysts with wide application potential.

Recent Advances in Near Infrared Upconverting Nanomaterials for Targeted Photodynamic Therapy of Cancer

Photodynamic therapy (PDT) is a well-established treatment of cancer that uses the toxic reactive oxygen species, including singlet oxygen (1O2), generated by photosensitiser drugs following irradiation of a specific wavelength to destroy the cancerous cells and tumours. Visible light is commonly used as the excitation source in PDT, which is not ideal for cancer treatment due to its reduced tissue penetration, and thus inefficiency to treat deep-lying tumours. Additionally, these wavelengths exhibit elevated autofluorescence background from the biological tissues which hinders optical biomedical imaging. An alternative to UV-Vis irradiation is the use of near infrared (NIR) excitation for PDT. This can be achieved using upconverting nanoparticles (UCNPs) functionalised with photosensitiser (PS) drugs where UCNPs can be used as an indirect excitation source for the activation of PS drugs yielding to the production of singlet 1O2 following NIR excitation. The use of nanoparticles for PDT is also beneficial due to their tumour targeting capability, either passively via the enhanced permeability and retention (EPR) effect or actively via stimuli-responsive targeting and ligand-mediated targeting (ie. using recognition units that can bind specific receptors only present or overexpressed on tumour cells). Here, we review recent advances in NIR upconverting nanomaterials for PDT of cancer with a clear distinction between those reported nanoparticles that could potentially target the tumour due to accumulation via the EPR effect (passive targeting) and nanoparticle-based systems that contain targeting agents with the aim of actively target the tumour via a molecular recognition process.

Recent advances in ZnO-based photosensitizers: Synthesis, modification, and applications in photodynamic cancer therapy

Zinc oxide nanoparticles (ZnO NPs) are important semiconductor materials with interesting photo-responsive properties. During the past, ZnO-based NPs have received considerable attention for photodynamic therapy (PDT) due to their biocompatibility and excellent potential of generating tumor-killing reactive oxygen species (ROS) through gentle photodynamic activation. This article provides a comprehensive review of the recent developments and improvements in optical properties of ZnO NPs as photosensitizers for PDT. The optical properties of ZnO-based photosensitizers are significantly dependent on their charge separation, absorption potential, band gap engineering, and surface area, which can be adjusted/tuned by doping, compositing, and morphology control. Here, we first summarize the recent progress in the charge separation capability, absorption potential, band gap engineering, and surface area of nanosized ZnO-based photosensitizers. Then, morphology control that is closely related to their synthesis method is discussed. Following on, the state-of-art for the ZnO-based NPs in the treatment of hypoxic tumors is comprehensively reviewed. Finally, we provide some outlooks on common targeted therapy methods for more effective tumor killing, including the attachment of small molecules, antibodies, ligands molecules, and receptors to NPs which further improve their selective distribution and targeting, hence improving the therapeutic effectiveness. The current review may provide useful guidance for the researchers who are interested in this promising dynamic cancer treatment technology.

Bismuth Oxychloride Nanomaterials Fighting for Human Health: From Photodegradation to Biomedical Applications

Environmental pollution and various diseases seriously affect the health of human beings. Photocatalytic nanomaterials (NMs) have been used for degrading pollution for a long time. However, the biomedical applications of photocatalytic NMs have only recently been investigated. As a typical photocatalytic NM, bismuth oxychloride (BiOCl) exhibits excellent photocatalytic performance due to its unique layered structure, electronic properties, optical properties, good photocatalytic activity, and stability. Some environmental pollutants, such as volatile organic compounds, antibiotics and their derivatives, heavy metal ions, pesticides, and microorganisms, could not only be detected but also be degraded by BiOCl-based NMs due to their excellent photocatalytic and photoelectrochemical properties. In particular, BiOCl-based NMs have been used as theranostic platforms because of their CT and photoacoustic imaging abilities, as well as photodynamic and photothermal performances. However, some reviews have only profiled the applications of dye degradation, hydrogen or oxygen production, carbon dioxide reduction, or nitrogen fixation of BiOCl NMs. There is a notable knowledge gap regarding the systematic study of the relationship between BiOCl NMs and human health, especially the biomedical applications of BiOCl-based NMs. As a result, in this review, the recent progress of BiOCl-based photocatalytic degradation and biomedical applications are summarized, and the improvement of BiOCl-based NMs in environmental and healthcare fields are also discussed. Finally, a few insights into the current status and future perspectives of BiOCl-based NMs are given.

Engineered titania nanomaterials in advanced clinical applications

Significant advancement in the field of nanotechnology has raised the possibility of applying potent engineered biocompatible nanomaterials within biological systems for theranostic purposes. Titanium dioxide (titanium(IV) oxide/titania/TiO₂) has garnered considerable attention as one of the most extensively studied metal oxides in clinical applications. Owing to the unique properties of titania, such as photocatalytic activity, excellent biocompatibility, corrosion resistance, and low toxicity, titania nanomaterials have revolutionized therapeutic approaches. Additionally, titania provides an exceptional choice for developing innovative medical devices and the integration of functional moieties that can modulate the biological responses. Thus, the current review aims to present a comprehensive and up-to-date overview of TiO₂-based nanotherapeutics and the corresponding future challenges.

Phototherapeutic anticancer strategies with first-row transition metal complexes: a critical review

Photodynamic therapy (PDT) and photoactivated chemotherapy (PACT) are therapeutic techniques based on a photosensitizer (PS) and light. These techniques allow the spatial and temporal control of the activation of drugs with light. Transition metal complexes are attractive compounds as photoactivatable prodrugs since their excited states can be appropriately designed by subtle modifications of the ligands, the metal centre, or the oxidation state. However, most metal-based PSs contain heavy metals such as Ru, Os, Ir, Pt or Au, which are expensive and non-earth-abundant, contrary to first-row transition metals. In this context, the exploration of the photochemical properties of complexes based on first-row transition metals appears to be extremely promising. This did encourage several groups to develop promising PSs based on these metals. This review presents up-to-date state-of-the-art information on first-row-transition metal complexes, from titanium to zinc in regard to their application as PSs for phototherapeutic applications.

2D Piezoelectric Bi2 MoO6 Nanoribbons for GSH-Enhanced Sonodynamic Therapy

Reducing the scavenging capacity of reactive oxygen species (ROS) and elevating ROS production are two primary goals of developing novel sonosensitizers for sonodynamic therapy (SDT). Hence, ultrathin 2D Bi₂ MoO₆ -poly(ethylene glycol) nanoribbons (BMO NRs) are designed as piezoelectric sonosensitizers for glutathione (GSH)-enhanced SDT. In cancer cells, BMO NRs can consume endogenous GSH to disrupt redox homeostasis, and the GSH-activated BMO NRs (GBMO) exhibit an oxygen-deficient structure, which can promote the separation of electron-hole pairs, thereby enhancing the efficiency of ROS production in SDT. The ultrathin GBMO NRs are piezoelectric, in which ultrasonic waves introduce mechanical strain to the nanoribbons, resulting in piezoelectric polarization and band tilting, thus accelerating toxic ROS production. The as-synthesized BMO NRs enable excellent computed tomography imaging of tumors and significant tumor suppression in vitro and in vivo. A piezoelectric Bi₂ MoO₆ sonosensitizer-mediated two-step enhancement SDT process, which is activated by endogenous GSH and amplified by exogenous ultrasound, is proposed. This process not only provides new options for improving SDT but also broadens the application of 2D piezoelectric materials as sonosensitizers in SDT.

Hafnium Oxide-Based Nanoplatform for Combined Chemoradiotherapy

Recently, the combined therapy has become one of the main approaches in cancer treatment. Combining different approaches may provide a significant outcome by triggering several death mechanisms or causing increased damage of tumor cells without hurting healthy ones. The supramolecular nanoplatform based on a high-Z metal reported here is a suitable system for the targeted delivery of chemotherapeutic compounds, imaging, and an enhanced radiotherapy outcome. HfO₂ nanoparticles coated with oleic acid and a monomethoxypoly(ethylene glycol)-poly(ε-caprolactone) copolymer shell (nanoplatform) are able to accumulate inside cancer cells and release doxorubicin (DOX) under specific conditions. Neither uncoated nor coated nanoparticles show any cytotoxicity in vitro. DOX loaded onto a nanoplatform demonstrates a lower IC₅₀ value than pure DOX. X-ray irradiation of cancer cells loaded with a nanoplatform shows a higher death rate than that for cells without nanoparticles. These results provide an important foundation for the development of complex nanoscale systems for combined cancer treatment.

Synergistic biocidal effects of metal oxide nanoparticles-assisted ultrasound irradiation: Antimicrobial sonodynamic therapy against Streptococcus mutans biofilms

BACKGROUND

Antimicrobial sonodynamic therapy (aSDT) is an adjunctive modality, which uses ultrasound irradiation to kill microbial cells by the activation of a sonosensitizer. The aim of this study was to evaluated the synergistic biocidal effects of zinc oxide nanoparticles (ZnO NPs) and titanium dioxide nanoparticles (TiO₂ NPs) as the metal oxide nanoparticles (MONPs)-assisted ultrasound irradiation against Streptococcus mutans biofilms.

MATERIALS AND METHODS

Following preparation and characterization of MONPs, cellular uptake and generation of intracellular reactive oxygen species (ROS) were assessed. After determination of the sub-significant reduction (SSR) doses of ZnO NPs, TiO₂ NPs, ZnO/TiO₂ NPs, and ultrasound intensity against S. mutans, anti-biofilm effects of aSDT were assessed using colorimetric assay, plate counting, and field emission scanning electron microscope (FESEM) analysis. Also, the metabolic activity of S. mutans and the expression levels of glucosyltransferase B (gtfB) as a main virulence factor of S. mutans were evaluated by XTT assay and quantitative real-time polymerase chain reaction following ZnO/TiO₂ NPs^SSR- mediated aSDT.

RESULTS

The finding of this study showed that an incubation time of 5 min was sufficient to achieve maximal uptake of MONPs. The ROS production following aSDT using ZnO NPs, TiO₂ NPs, and ZnO/TiO₂ NPs were ~ 4.1-, 5.6-, and 11.7-fold increase, respectively. The dose-dependent reduction in cell viability of S. mutans was revealed by increasing the concentrations of ZnO NPs, TiO₂ NPs, ZnO/TiO₂, as well as ultrasound intensities. According to the data, 1.5 µg/mL, 3.1 µg/mL, 25 µg/mL, and 0.75 W/cm² were considered as the SSR doses of ZnO/TiO₂ NPs, ZnO NPs, TiO₂ NPs, and ultrasound intensity, respectively (P>0.05). ZnO/TiO₂ NPs^SSR-mediated aSDT showed a significantly higher biofilm inhibitory activity than the other treatment groups (P<0.05). Based on the FE-SEM analysis, aSDT based on the ZnO/TiO₂ NPs^SSR had a strong anti-biofilm effect against preformed biofilms of S. mutans on the enamel slabs. Also, the metabolic activity of S. mutans and the expression levels of gtfB were significantly decreased to 85.5% and 12.3-fold, respectively following ZnO/TiO₂ NPs^SSR-mediated aSDT (P<0.05). No considerable difference was observed in anti-biofilm activity between ZnO/TiO₂ NPs^SSR- mediated aSDT and 0.2% CHX (P>0.05).

CONCLUSION

The results revealed anti-metabolic and anti-biofilm potential activities of ZnO/TiO₂ NPs-mediated aSDT against S. mutans with the highest cellular uptake and ROS generation.

Enhanced radiotherapy efficacy of breast cancer multi cellular tumor spheroids through in-situ fabricated chitosan-zinc oxide bio-nanocomposites as radio-sensitizing agents

Overwhelming evidence has shown that three-dimensional multicellular tumor spheroids (MCTSs) as a mimic of in-vivo tumor can accurately exhibit cellular responses to treatments. So, we compared the capability of pure zinc oxide nanoparticles (ZnO-NPs) and chitosan-ZnO bio-nanocomposites (CS-ZnO BNCs) for enhancing the radiosensitization of MDA-MB-231 breast cancer cells (BCCs) in the 3D-MCTSs model. ZnO-NPs and CS-ZnO BNCs were synthesized by a facile co-precipitation method. FE-SEM images revealed that the uniform spherical ZnO-NPs with an average diameter of 35 nm were successfully dispersed on chitosan. MDA-MB-231 MCTSs which were formed in a non-adherent culture plate, possessed functional features of in-vivo tumor. The priority of such culture method to conventionally used 2D monolayer (or parental) cell culture is the mimicking of tumor microenvironment. The toxicity of CS-ZnO BNCs and ZnO-NPs against the MDA-M-231 BCCs was evaluated using MTT-colorimetric assay, which demonstrated superior biocompatibility of CS-ZnO BNCs compared to pure ZnO-NPs (even at high concentration of 100 μg/mL). Survival fraction analysis of cells under clinical X-ray irradiation (6 MV) showed that MCTSs had a higher radioresistance compared to parental cells. Besides, the clonogenic potential of irradiated MCTSs was significantly decreased by the addition of CS-ZnO BNCs similar to that of monolayer cells. The sensitivity enhancement ratios (SER) for MCTSs and monolayer cells were calculated 1.5 and 1.63, respectively. Further, tracking of radiobiological properties and apoptosis induction of MCTSs showed that CS-ZnO BNCs not only could lead to the creation of higher radiation-induced complex DNA break and apoptosis death in MCTSs, but also weakened DNA repair mechanisms. It was found that non-toxic concentration of CS-ZnO BNCs has promising potential to enhance radiosensitivity of resistant-MCTSs as a superior in-vitro tumor model. So, CS-ZnO BNCs can be a prominent candidate for overcoming the resistance of BCCs to radiotherapy.

TiO2 nanoparticle coatings on glass surfaces for the selective trapping of leukemia cells from peripheral blood

Photodynamic therapy (PDT) using TiO₂ nanoparticles has become an important alternative treatment for different types of cancer due to their high photocatalytic activity and high absorption of UV-A light. To potentiate this treatment, we have coated commercial glass plates with TiO₂ nanoparticles prepared by the sol-gel method (TiO₂ -m), which exhibit a remarkable selectivity for the irreversible trapping of cancer cells. The physicochemical properties of the deposited TiO₂ -m nanoparticle coatings have been characterized by a number of complementary surface-analytical techniques and their interaction with leukemia and healthy blood cells were investigated. Scanning electron and atomic force microscopy verify the formation of a compact layer of TiO₂ -m nanoparticles. The particles are predominantly in the anatase phase and have hydroxyl-terminated surfaces as revealed by Raman, X-ray photoelectron, and infrared spectroscopy, as well as X-ray diffraction. We find that lymphoblastic leukemia cells adhere to the TiO₂ -m coating and undergo amoeboid-like migration, whereas lymphocytic cells show distinctly weaker interactions with the coating. This evidences the potential of this nanomaterial coating to selectively trap cancer cells and renders it a promising candidate for the development of future prototypes of PDT devices for the treatment of leukemia and other types of cancers with non-adherent cells.

Nanostructured TiO2 cavitation agents for dual-modal sonophotocatalysis with pulsed ultrasound

Current sonochemical methods rely on spatially uncontrolled cavitation for radical species generation to promote chemical reactions. To improve radical generation, sonosensitizers have been demonstrated to be activated by cavitation-based light emission (sonoluminescence). Unfortunately, this process remains relatively inefficient compared to direct photocatalysis, due to the physical separation between cavitation event and sonosensitizing agent. In this study, we have synthesized nanostructured titanium dioxide particles to couple the source for cavitation within a photocatalytic site to create a sonophotocatalyst. In doing so, we demonstrate that site-controlled cavitation from the nanoparticles using pulsed ultrasound at reduced acoustic powers resulted in the sonochemical degradation methylene blue at rates nearly three orders of magnitude faster than other titanium dioxide-based nanoparticles by conventional methods. Sonochemical degradation was directly proportional to the measured cavitation produced by these sonophotocatalysts. Our work suggests that simple nanostructuring of current sonosensitizers to enable on-site cavitation greatly enhances sonochemical reaction rates.

Promoting reactive oxygen species generation: a key strategy in nanosensitizer-mediated radiotherapy

The radiotherapy enhancement effect of numerous nanosensitizers is based on the excessive production of reactive oxygen species (ROS), and only a few systematic reviews have focused on the key strategy in nanosensitizer-mediated radiotherapy. To clarify the mechanism underlying this effect, it is necessary to understand the role of ROS in radiosensitization before clinical application. Thus, the source of ROS and their principle of tumor inhibition are first introduced. Then, nanomaterial-mediated ROS generation in radiotherapy is reviewed. The double-edged sword effect of ROS and the potential dangers they may pose to cancer patients are subsequently addressed. Finally, future perspectives regarding ROS-regulated nanosensitizer applications and development are discussed.

Stanene-Based Nanosheets for β-Elemene Delivery and Ultrasound-Mediated Combination Cancer Therapy

Ultrasound (US)-mediated sonodynamic therapy (SDT) has emerged as a superior modality for cancer treatment owing to the non-invasiveness and high tissue-penetrating depth. However, developing biocompatible nanomaterial-based sonosensitizers with efficient SDT capability remains challenging. Here, we employed a liquid-phase exfoliation strategy to obtain a new type of two-dimensional (2D) stanene-based nanosheets (SnNSs) with a band gap of 2.3 eV, which is narrower than those of the most extensively studied nano-sonosensitizers, allowing a more efficient US-triggered separation of electron (e^- )-hole (h⁺ ) pairs for reactive oxygen species (ROS) generation. In addition, we discovered that such SnNSs could also serve as robust near-infrared (NIR)-mediated photothermal therapy (PTT) agents owing to their efficient photothermal conversion, and serve as nanocarriers for anticancer drug delivery owing to the inherent 2D layered structure. This study not only presents general nanoplatforms for SDT-enhanced combination cancer therapy, but also highlights the utility of 2D SnNSs to the field of nanomedicine.

Applications of Micro/Nanotechnology in Ultrasound-based Drug Delivery and Therapy for Tumor

Ultrasound has been broadly used in biomedicine for both tumor diagnosis as well as therapy. The applications of recent developments in micro/nanotechnology promote the development of ultrasound-based biomedicine, especially in the field of ultrasound-based drug delivery and tumor therapy. Ultrasound can activate nano-sized drug delivery systems by different mechanisms for ultrasound- triggered on-demand drug release targeted only at the tumor sites. Ultrasound Targeted Microbubble Destruction (UTMD) technology can not only increase the permeability of vasculature and cell membrane via sonoporation effect but also achieve in situ conversion of microbubbles into nanoparticles to promote cellular uptake and therapeutic efficacy. Furthermore, High Intensity Focused Ultrasound (HIFU), or Sonodynamic Therapy (SDT), is considered to be one of the most promising and representative non-invasive treatment for cancer. However, their application in the treatment process is still limited due to their critical treatment efficiency issues. Fortunately, recently developed micro/nanotechnology offer an opportunity to solve these problems, thus improving the therapeutic effect of cancer. This review summarizes and discusses the recent developments in the design of micro- and nano- materials for ultrasound-based biomedicine applications.

Reactive Oxygen Species-Regulating Strategies Based on Nanomaterials for Disease Treatment

Reactive oxygen species (ROS) play an essential role in physiological and pathological processes. Studies on the regulation of ROS for disease treatments have caused wide concern, mainly involving the topics in ROS-regulating therapy such as antioxidant therapy triggered by ROS scavengers and ROS-induced toxic therapy mediated by ROS-elevation agents. Benefiting from the remarkable advances of nanotechnology, a large number of nanomaterials with the ROS-regulating ability are developed to seek new and effective ROS-related nanotherapeutic modalities or nanomedicines. Although considerable achievements have been made in ROS-based nanomedicines for disease treatments, some fundamental but key questions such as the rational design principle for ROS-related nanomaterials are held in low regard. Here, the design principle can serve as the initial framework for scientists and technicians to design and optimize the ROS-regulating nanomedicines, thereby minimizing the gap of nanomedicines for biomedical application during the design stage. Herein, an overview of the current progress of ROS-associated nanomedicines in disease treatments is summarized. And then, by particularly addressing these known strategies in ROS-associated therapy, several fundamental and key principles for the design of ROS-associated nanomedicines are presented. Finally, future perspectives are also discussed in depth for the development of ROS-associated nanomedicines.

Impact of zinc oxide nanoparticles and thymoquinone in Ehrlich ascites carcinoma induced in mice

BACKGROUND

The field of nanotechnology offers great opportunities for cancer therapy.

OBJECTIVE

This study aimed to compare the therapeutic impact of Zn oxide nanoparticles (ZnO NPs) and thymoquinone (TQ) alone or as cotherapy in Ehrlich ascites carcinoma (EAC) induced in mice.

MATERIALS AND METHODS

This study was performed on 75 female albino mice divided into Group I: EAC-bearing control group, Group II: EAC treated with TQ, Group III: EAC treated with low-dose ZnO NPs, Group IV: EAC treated with high-dose ZnO NPs, Group V: EAC treated with TQ and low-dose ZnO NPs. All groups were subjected to measurement of cell viability, ascites fluid volume, Bcl2 protein expression by Western blot analysis, cyclooxygenase 2 (COX2) gene expression by a real-time polymerase chain reaction, enzyme-linked immunosorbent assay levels of Beclin 1, interferon γ (INFγ), interleukin 13 (IL-13), and estimation of Zn concentrations in EAC cells and liver homogenate to evaluate its toxicity.

RESULTS

Cotherapy has an efficient anticancer effect by enhancing apoptosis and autophagy, resulting in reducing tumor cell viability and ascites fluid volume together with downregulation of Bcl2 protein expression. This cotherapy increases Beclin 1 and INFγ and decreases IL-13. ZnO NPs upregulate COX2 expression, whereas TQ downregulates its expression. High-dose ZnO NPs have more toxic effects on liver enzymes. Using TQ together with ZnO NPs can eliminate ZnO NPs liver toxicity.

CONCLUSION

The cotherapy has an efficient anticancer effect by enhancing apoptosis and autophagy. High-dose ZnO NPs have more toxic effects on liver enzymes. Using TQ together with ZnO NPs can eliminate ZnO NP liver toxicity.

External and Internal Stimuli-Responsive Metallic Nanotherapeutics for Enhanced Anticancer Therapy

Therapeutic, diagnostic, and imaging approaches based on nanotechnology offer distinct advantages in cancer treatment. Various nanotherapeutics have been presented as potential alternatives to traditional anticancer therapies such as chemotherapy, radiotherapy, and surgical intervention. Notably, the advantage of nanotherapeutics is mainly attributable to their accumulation and targeting ability toward cancer cells, multiple drug-carrying abilities, combined therapies, and imaging approaches. To date, numerous nanoparticle formulations have been developed for anticancer therapy and among them, metallic nanotherapeutics reportedly demonstrate promising cancer therapeutic and diagnostic efficiencies owing to their dense surface functionalization ability, uniform size distribution, and shape-dependent optical responses, easy and cost-effective synthesis procedure, and multiple anti-cancer effects. Metallic nanotherapeutics can remodel the tumor microenvironment by changing unfavorable therapeutic conditions into therapeutically accessible ones with the help of different stimuli, including light, heat, ultrasound, an alternative magnetic field, redox, and reactive oxygen species. The combination of metallic nanotherapeutics with both external and internal stimuli can be used to trigger the on-demand release of therapeutic molecules, augmenting the therapeutic efficacies of anticancer therapies such as photothermal therapy, photodynamic therapy, magnetic hyperthermia, sonodynamic therapy, chemodynamic therapy, and immunotherapy. In this review, we have summarized the role of different metallic nanotherapeutics in anti-cancer therapy, as well as their combinational effects with multiple stimuli for enhanced anticancer therapy.

K. PK, Lee J, Kim CH, You DG, Park JH. Recent advances in nanomaterial-based augmented sonodynamic therapy of cancer

This review focuses on recent advances in augmented sonodynamic therapy (SDT) using engineered nanomaterials, and the mechanism of SDT for discussing future perspectives.

Nanomedicine: Photo-activated nanostructured titanium dioxide, as a promising anticancer agent

The multivariate condition of cancer disease has been approached in various ways, by the scientific community. Recent studies focus on individualized treatments, minimizing the undesirable consequences of the conventional methods, but the development of an alternative effective therapeutic scheme remains to be held. Nanomedicine could provide a solution, filling this gap, exploiting the unique properties of innovative nanostructured materials. Nanostructured titanium dioxide (TiO₂) has a variety of applications of daily routine and of advanced technology. Due to its biocompatibility, it has also a great number of biomedical applications. It is now clear that photo-excited TiO₂ nanoparticles, induce generation of pairs of electrons and holes which react with water and oxygen to yield reactive oxygen species (ROS) that have been proven to damage cancer cells, triggering controlled cellular processes. The aim of this review is to provide insights into the field of nanomedicine and particularly into the wide context of TiO₂-NP-mediated anticancer effect, shedding light on the achievements of nanotechnology and proposing this nanostructured material as a promising anticancer photosensitizer.

Biomimetic Amorphous Titania Nanoparticles as Ultrasound Responding Agents to Improve Cavitation and ROS Production for Sonodynamic Therapy

Conventional therapies to treat cancer often exhibit low specificity, reducing the efficiency of the treatment and promoting strong side effects. To overcome these drawbacks, new ways to fight cancer cells have been developed so far focusing on nanosystems. Different action mechanisms to fight cancer cells have been explored using nanomaterials, being their remote activation one of the most promising. Photo- and sonodynamic therapies are relatively new approaches that emerged following this idea. These therapies are based on the ability of specific agents to generate highly cytotoxic reactive oxygen species (ROS) by external stimulation with light or ultrasounds (US), respectively. Crystalline (TiO2) and amorphous titania (a-TiO2) nanoparticles (NPs) present a set of very interesting characteristics, such as their photo-reactivity, photo stability, and effective bactericidal properties. Their production is inexpensive and easily scalable; they are reusable and demonstrated already to be nontoxic. Therefore, these NPs have been increasingly studied as promising photo- or sonosensitizers to be applied in photodynamic/sonodynamic therapies in the future. However, they suffer from poor colloidal stability in aqueous and biological relevant media. Therefore, various organic and polymer-based coatings have been proposed. In this work, the role of a-TiO2 based NPs synthesized through a novel, room-temperature, base-catalyzed, sol-gel protocol in the generation of ROS and as an enhancer of acoustic inertial cavitation was evaluated under ultrasound irradiation. A novel biomimetic coating based on double lipidic bilayer, self-assembled on the a-TiO2-propylamine NPs, is proposed to better stabilize them in water media. The obtained results show that the biomimetic a-TiO2-propylamine NPs are promising candidates to be US responding agents, since an improvement of the cavitation effect occurs in presence of the developed NPs. Further studies will show their efficacy against cancer cells.

Remotely Activated Nanoparticles for Anticancer Therapy

Cancer has nowadays become one of the leading causes of death worldwide. Conventional anticancer approaches are associated with different limitations. Therefore, innovative methodologies are being investigated, and several researchers propose the use of remotely activated nanoparticles to trigger cancer cell death. The idea is to conjugate two different components, i.e., an external physical input and nanoparticles. Both are given in a harmless dose that once combined together act synergistically to therapeutically treat the cell or tissue of interest, thus also limiting the negative outcomes for the surrounding tissues. Tuning both the properties of the nanomaterial and the involved triggering stimulus, it is possible furthermore to achieve not only a therapeutic effect, but also a powerful platform for imaging at the same time, obtaining a nano-theranostic application. In the present review, we highlight the role of nanoparticles as therapeutic or theranostic tools, thus excluding the cases where a molecular drug is activated. We thus present many examples where the highly cytotoxic power only derives from the active interaction between different physical inputs and nanoparticles. We perform a special focus on mechanical waves responding nanoparticles, in which remotely activated nanoparticles directly become therapeutic agents without the need of the administration of chemotherapeutics or sonosensitizing drugs.