Stimuli-responsive nanoscale drug delivery systems for cancer therapy

Stimuli-responsive delivery systems using carbohydrate polymers: A review

Carbohydrate polymers, including Chitosan, Cellulose, Starch, Dextran, Pectin, Alginate, and Hyaluronic Acid, have been considered as stimuli-responsive biopolymers demonstrating significant potential for drug delivery approaches. Relying on the specific design and fabrication, such biopolymers are able to respond to fluctuations in pH, temperature, or enzymatic activity. This review investigates stimuli-responsive biopolymers, known as carbohydrate polymers, mainly chitosan, cellulose, and alginate, utilized as drug delivery approaches, emphasizing that these stimuli-responsive biopolymers accelerate controlled drug release. The pH-responsive delivery systems selectively target acidic tumor microenvironments, while temperature-responsive materials provide precise control for drug release produced by hyperthermia. Light-responsive biopolymers provide spatial and temporal control, providing appropriate for targeted therapy. Redox-responsive structures are especially efficient in responding to elevated glutathione (GSH) in tumor microenvironment, facilitating targeted drug release. Electro- and magnetic-responsive systems provide remote control functionalities, improving the accuracy of drug administration. The incorporation of multi-stimuli-responsive mechanisms implies a remarkable progression in drug delivery, providing a more versatile and adaptable framework for therapeutic applications. Accordingly, the future research on carbohydrate polymer-based stimuli-responsive delivery systems should focus on improving the responsiveness and targeting efficacy through complicated optimization of features and performance of carbohydrate polymers, where the integration of multifunctional moieties facilitates transformation of targeted drugs for broader biological functions.

Cancer theragnostics: closing the loop for advanced personalized cancer treatment through the platform integration of therapeutics and diagnostics

Cancer continues to be one of the leading causes of death worldwide, and conventional cancer therapies such as chemotherapy, radiation therapy, and surgery have limitations. RNA therapy and cancer vaccines hold considerable promise as an alternative to conventional therapies for their ability to enable personalized therapy with improved efficacy and reduced side effects. The principal approach of cancer vaccines is to induce a specific immune response against cancer cells. However, a major challenge in cancer immunotherapy is to predict which patients will respond to treatment and to monitor the efficacy of the vaccine during treatment. Theragnostics, an integration of diagnostic and therapeutic capabilities into a single hybrid platform system, has the potential to address these challenges by enabling real-time monitoring of treatment response while allowing endogenously controlled personalized treatment adjustments. In this article, we review the current state-of-the-art in theragnostics for cancer vaccines and RNA therapy, including imaging agents, biomarkers, and other diagnostic tools relevant to cancer, and their application in cancer therapy development and personalization. We also discuss the opportunities and challenges for further development and clinical translation of theragnostics in cancer vaccines.

Exploiting lignin-based nanomaterials for enhanced anticancer therapy: A comprehensive review and future direction

Lignin, a renewable and abundant natural polymer, has emerged as a promising candidate for anticancer therapy due to its unique properties and biocompatibility. This review provides a comprehensive overview of recent advancements in the utilization of lignin-based nanomaterials for enhancing anticancer drug delivery and therapeutic outcomes. A detailed examination of the literature reveals several synthesis methods, including nanoprecipitation, microemulsion, and solvent exchange, which produce lignin nanoparticles with improved drug solubility and bioavailability. The anticancer mechanisms of lignin nanoparticles, such as the generation of reactive oxygen species (ROS), induction of apoptosis, and enhanced cellular uptake, are also explored. Lignin nanoparticles loaded with drugs like curcumin, doxorubicin, camptothecin, and resveratrol have demonstrated the ability to improve drug efficacy, selectively target cancer cells, overcome multidrug resistance, and minimize toxicity in both in vitro and in vivo studies. These nanoparticles have shown significant potential in suppressing tumor growth, inducing cell death through apoptotic pathways, and enhancing the synergistic effects of combination therapies, such as chemo-phototherapy. Future research directions include optimizing lignin nanoparticle formulations for clinical applications, refining targeted delivery mechanisms to cancer cells, and conducting thorough biocompatibility and toxicity assessments. Overall, this review highlights the significant progress made in utilizing lignin-based nanomaterials for cancer therapy and outlines promising areas for further exploration in this rapidly evolving field.

Strategies for the development of metalloimmunotherapies

Metal ions play crucial roles in the regulation of immune pathways. In fact, metallodrugs have a long record of accomplishment as effective treatments for a wide range of diseases. Here we argue that the modulation of interactions of metal ions with molecules and cells involved in the immune system forms the basis of a new class of immunotherapies. By examining how metal ions modulate the innate and adaptive immune systems, as well as host-microbiota interactions, we discuss strategies for the development of such metalloimmunotherapies for the treatment of cancer and other immune-related diseases.

Biomedical applications of stimuli-responsive nanomaterials

Nanomaterials have aroused great interests in drug delivery due to their nanoscale structure, facile modifiability, and multifunctional physicochemical properties. Currently, stimuli-responsive nanomaterials that can respond to endogenous or exogenous stimulus display strong potentials in biomedical applications. In comparison with conventional nanomaterials, stimuli-responsive nanomaterials can improve therapeutic efficiency and reduce the toxicity of drugs toward normal tissues through specific targeting and on-demand drug release at pathological sites. In this review, we summarize the responsive mechanism of a variety of stimulus, including pH, redox, and enzymes within pathological microenvironment, as well as exogenous stimulus such as thermal effect, magnetic field, light, and ultrasound. After that, biomedical applications (e.g., drug delivery, imaging, and theranostics) of stimuli-responsive nanomaterials in a diverse array of common diseases, including cardiovascular diseases, cancer, neurological disorders, inflammation, and bacterial infection, are presented and discussed. Finally, the remaining challenges and outlooks of future research directions for the biomedical applications of stimuli-responsive nanomaterials are also discussed. We hope that this review can provide valuable guidance for developing stimuli-responsive nanomaterials and accelerate their biomedical applications in diseases diagnosis and treatment.

Regulating Drug Release Performance of Acid-Triggered Dimeric Prodrug-Based Drug Self-Delivery System by Altering Its Aggregation Structure

Dimeric prodrugs have been investigated intensely as carrier-free drug self-delivery systems (DSDSs) in recent decades, and their stimuli-responsive drug release has usually been controlled by the conjugations between the drug molecules, including the stimuli (pH or redox) and responsive sensitivity. Here, an acid-triggered dimeric prodrug of doxorubicin (DOX) was synthesized by conjugating two DOX molecules with an acid-labile ketal linker. It possessed high drug content near the pure drug, while the premature drug leakage in blood circulation was efficiently suppressed. Furthermore, its aggregation structures were controlled by fabricating nanomedicines via different approaches, such as fast precipitation and slow self-assembly, to regulate the drug release performance. Such findings are expected to enable better anti-tumor efficacy with the desired drug release rate, beyond the molecular structure of the dimeric prodrug.

Chitosan-based nanosystems for cancer diagnosis and therapy: Stimuli-responsive, immune response, and clinical studies

Cancer, a global health challenge of utmost severity, necessitates innovative approaches beyond conventional treatments (e.g., surgery, chemotherapy, and radiation therapy). Unfortunately, these approaches frequently fail to achieve comprehensive cancer control, characterized by inefficacy, non-specific drug distribution, and the emergence of adverse side effects. Nanoscale systems based on natural polymers like chitosan have garnered significant attention as promising platforms for cancer diagnosis and therapy owing to chitosan's inherent biocompatibility, biodegradability, nontoxicity, and ease of functionalization. Herein, recent advancements pertaining to the applications of chitosan nanoparticles in cancer imaging and drug/gene delivery are deliberated. The readers are introduced to conventional non-stimuli-responsive and stimuli-responsive chitosan-based nanoplatforms. External triggers like light, heat, and ultrasound and internal stimuli such as pH and redox gradients are highlighted. The utilization of chitosan nanomaterials as contrast agents or scaffolds for multimodal imaging techniques e.g., magnetic resonance, fluorescence, and nuclear imaging is represented. Key applications in targeted chemotherapy, combination therapy, photothermal therapy, and nucleic acid delivery using chitosan nanoformulations are explored for cancer treatment. The immunomodulatory effects of chitosan and its role in impacting the tumor microenvironment are analyzed. Finally, challenges, prospects, and future outlooks regarding the use of chitosan-based nanosystems are discussed.

Highly Efficient Photoswitchable Smart Polymeric Nanovehicle for Gene and Anticancer Drug Delivery in Triple-Negative Breast Cancer

Over the past few decades, there has been significant interest in smart drug delivery systems capable of carrying multiple drugs efficiently, particularly for treating genetic diseases such as cancer. Despite the development of various drug delivery systems, a safe and effective method for delivering both anticancer drugs and therapeutic genes for cancer therapy remains elusive. In this study, we describe the synthesis of a photoswitchable smart polymeric vehicle comprising a photoswitchable spiropyran moiety and an amino-acid-based cationic monomer-based block copolymer using reversible addition-fragmentation chain transfer (RAFT) polymerization. This system aims at diagnosing triple-negative breast cancer and subsequently delivering genes and anticancer agents. Triple-negative breast cancer patients have elevated concentrations of Cu2+ ions, making them excellent targets for diagnosis. The polymer can detect Cu2+ ions with a low limit of detection value of 9.06 nM. In vitro studies on doxorubicin drug release demonstrated sustained delivery at acidic pH level similar to the tumor environment. Furthermore, the polymer exhibited excellent blood compatibility even at the concentration as high as 500 μg/mL. Additionally, it displayed a high transfection efficiency of approximately 82 ± 5% in MDA-MB-231 triple-negative breast cancer cells at an N/P ratio of 50:1. It is observed that mitochondrial membrane depolarization and intracellular reactive oxygen species generation are responsible for apoptosis and the higher number of apoptotic cells, which occurred through the arrest of the G2/M phase of the cell cycle were observed. Therefore, the synthesized light-responsive cationic polymer may be an effective system for diagnosis, with an efficient anticancer drug and gene carrier for the treatment of triple-negative breast cancer in the future.

Physicochemical Stimulus-Responsive Systems Targeted with Antibody Derivatives

The application of monoclonal antibodies and antibody fragments with the advent of recombinant antibody technology has made notable progress in clinical trials to provide a regulated drug release and extra targeting to the special conditions in the function site. Modification of antibodies has facilitated using mAbs and antibody fragments in numerous models of therapeutic and detection utilizations, such as stimuliresponsive systems. Antibodies and antibody derivatives conjugated with diverse stimuliresponsive materials have been constructed for drug delivery in response to a wide range of endogenous (electric, magnetic, light, radiation, ultrasound) and exogenous (temperature, pH, redox potential, enzymes) stimuli. In this report, we highlighted the recent progress on antibody-conjugated stimuli-responsive and dual/multi-responsive systems that affect modern medicine by improving a multitude of diagnostic and treatment strategies.

Recent advances of polymeric nanoplatforms for cancer treatment: smart delivery systems (SDS), nanotheranostics and multidrug resistance (MDR) inhibition

Nanotheranostics is a promising field that combines the benefits of diagnostic and treatment into a single nano-platform that not only administers treatment but also allows for real-time monitoring of therapeutic response, decreasing the possibility of under/over-drug dosing. Furthermore, developing smart delivery systems (SDSs) for cancer theranostics that can take advantage of various tumour microenvironment (TME) conditions (such as deformed tumour vasculature, various over-expressed receptor proteins, reduced pH, oxidative stress, and resulting elevated glutathione levels) can aid in achieving improved pharmacokinetics, higher tumour accumulation, enhanced antitumour efficacy, and/or decreased side effects and multidrug resistance (MDR) inhibition. Polymeric nanoparticles (PNPs) are being widely investigated in this regard due to their unique features such as small size, passive/active targeting possibility, better pharmaceutical kinetics and biological distribution, decreased adverse reactions of the established drugs, inherent inhibitory properties to MDR efflux pump proteins, as well as the feasibility of delivering numerous therapeutic substances in just one design. Hence in this review, we have primarily discussed PNPs based targeted and/or controlled SDSs in which we have elaborated upon different TME mediated nanotheranostic platforms (NTPs) including active/passive/magnetic targeting platforms along with pH/ROS/redox-responsive platforms. Besides, we have elucidated different imaging guided cancer therapeutic platforms based on four major cancer imaging techniques i.e., fluorescence/photo-acoustic/radionuclide/magnetic resonance imaging, Furthermore, we have deliberated some of the most recently developed PNPs based multimodal NTPs (by combining two or more imaging or therapy techniques on a single nanoplatform) in cancer theranostics. Moreover, we have provided a brief update on PNPs based NTP which are recently developed to overcome MDR for effective cancer treatment. Additionally, we have briefly discussed about the tissue biodistribution/tumour targeting efficiency of these nanoplatforms along with recent preclinical/clinical studies. Finally, we have elaborated on various limitations associated with PNPs based nanoplatforms.

Biodegradable polyester-based nano drug delivery system in cancer chemotherapy: a review of recent progress (2021-2023)

Cancer presents a formidable threat to human health, with the majority of cases currently lacking a complete cure. Frequently, chemotherapy drugs are required to impede its progression. However, these drugs frequently suffer from drawbacks such as poor selectivity, limited water solubility, low bioavailability, and a propensity for causing organ toxicity. Consequently, a concerted effort has been made to seek improved drug delivery systems. Nano-drug delivery systems based on biodegradable polyesters have emerged as a subject of widespread interest in this pursuit. Extensive research has demonstrated their potential for offering high bioavailability, effective encapsulation, controlled release, and minimal toxicity. Notably, poly (ε-caprolactone) (PCL), poly (lactic-co-glycolic acid) (PLGA), and polylactic acid (PLA) have gained prominence as the most widely utilized options as carriers of the nano drug delivery system. This paper comprehensively reviews recent research on these materials as nano-carriers for delivering chemotherapeutic drugs, summarizing their latest advancements, acknowledging their limitations, and forecasting future research directions.

Targeted drug delivery systems for elemene in cancer therapy: The story thus far

Elemene (ELE) is a group of broad-spectrum anticancer active ingredients with low toxicity extracted from traditional Chinese medicines (TCMs), such as Curcumae Rhizoma and Curcuma Radix, which can exert antitumour activities by regulating various signal pathways and targets. However, the strong hydrophobicity, short half-life, low bioavailability and weak in vivo targeting ability of ELE restrict its use. Targeted drug delivery systems based on nanomaterials are among the most viable methods to overcome these shortcomings. In this review, we first summarize recent studies on the clinical uses of ELE as an adjunct antitumour drug. ELE-based combination strategies have great promise for enhancing efficacy, reducing adverse reactions, and improving patients' quality of life and immune function. Second, we summarize recent studies on the antitumour mechanisms of ELE and ELE-based combination strategies. The potential mechanisms include inducing pyroptosis and ferroptosis, promoting senescence, regulating METTL3-mediated m6A modification, suppressing the Warburg effect, and inducing apoptosis and cell cycle arrest. Most importantly, we comprehensively summarize studies on the combination of targeted drug delivery systems with ELE, including passively and actively targeted drug delivery systems, stimuli-responsive drug delivery systems, and codelivery systems for ELE combined with other therapies, which have great promise in improving drug bioavailability, increasing drug targeting ability, controlling drug release, enhancing drug efficacy, reducing drug adverse effects and reversing MDR. Our summary will provide a reference for the combination of TCMs such as ELE with advanced targeted drug delivery systems in the future.

The synthesis and development of poly(ε-caprolactone) conjugated polyoxyethylene sorbitan oleate-based micelles for curcumin drug release: an in vitro study on breast cancer cells

BACKGROUND

it is now known that curcumin (Cur) has a broad range of biological properties; however, photosensitivity, as well as low bioavailability and short half-life, have limited its clinical application. To overcome these problems the synthesis of poly(ε-caprolactone)-Tween 80 (PCL-T) copolymers was performed.

METHODS

the copolymers of PCL-T were created using the solvent evaporation/extraction technique. Then Cur was loaded in PCL-T micelles (PCL-T-M) by a self-assembly method. The characterization of copolymer and micelles was assessed by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (1HNMR), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and dynamic light scattering (DLS) methods. The MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay was used to indicate the cytotoxicity of the free Cur, PCL-T-M, and Cur-loaded PCL-T-M.

RESULTS

TEM analysis showed monodispersed and spherical shapes with a size of about 90 nm. Cur was released from PCL-T-M at pH 7.4 (45%) and 5.5 (90%) during 6 days. After 24 and 48 h, the IC50 of the free Cur, PCL-T-M, and Cur-loaded PCL-T-M on MCF-7 cells were 80.86 and 54.45 μg mL-1, 278.30 and 236.19 μg mL-1, 45.47 and 19.05 μg mL-1, respectively.

CONCLUSION

this study showed that, in the same concentration, the effectiveness of the Cur-loaded PCL-T-M is more than the free Cur, and the nano-system has been able to overcome delivery obstacles of Cur drug. Thus, PCL-T-M can be a candidate as a drug carrier for the delivery of Cur and future therapeutic investigations on breast cancer.

Current Principles, Challenges, and New Metrics in pH-Responsive Drug Delivery Systems for Systemic Cancer Therapy

The paradigm of drug delivery via particulate formulations is one of the leading ideas that enable overcoming limitations of traditional chemotherapeutic agents. The trend toward more complex multifunctional drug carriers is well-traced in the literature. Nowadays, the prospectiveness of stimuli-responsive systems capable of controlled cargo release in the lesion nidus is widely accepted. Both endogenous and exogenous stimuli are employed for this purpose; however, endogenous pH is the most common trigger. Unfortunately, scientists encounter multiple challenges on the way to the implementation of this idea related to the vehicles' accumulation in off-target tissues, their immunogenicity, the complexity of drug delivery to intracellular targets, and finally, the difficulties in the fabrication of carriers matching all imposed requirements. Here, we discuss fundamental strategies for pH-responsive drug delivery, as well as limitations related to such carriers' application, and reveal the main problems, weaknesses, and reasons for poor clinical results. Moreover, we attempted to formulate the profiles of an "ideal" drug carrier in the frame of different strategies drawing on the example of metal-comprising materials and considered recently published studies through the lens of these profiles. We believe that this approach will facilitate the formulation of the main challenges facing researchers and the identification of the most promising trends in technology development.

Trends and perspectives on the commercialization of bioactive glasses

At least 25 bioactive glass (BG) medical devices have been approved for clinical use by global regulatory agencies. Diverse applications include monolithic implants, bone void fillers, dentin hypersensitivity agents, wound dressing, and cancer therapeutics. The morphology and delivery systems of bioactive glasses have evolved dramatically since the first devices based on 45S5 Bioglass®. The particle size of these devices has generally decreased with the evolution of bioactive glass technology but primarily lies in the micron size range. Morphologies have progressed from glass monoliths to granules, putties, and cements, allowing medical professionals greater flexibility and control. Compositions of these commercial materials have primarily relied on silicate-based systems with varying concentrations of sodium, calcium, and phosphorus. Furthermore, therapeutic ions have been investigated and show promise for greater control of biological stimulation of genetic processes and increased bioactivity. Some commercial products have exploited the borate and phosphate-based compositions for soft tissue repair/regeneration. Mesoporous BGs also promise anticancer therapies due to their ability to deliver drugs in combination with radiotherapy, photothermal therapy, and magnetic hyperthermia. The objective of this article is to critically discuss all clinically approved bioactive glass products. Understanding essential regulatory standards and rules for production is presented through a review of the commercialization process. The future of bioactive glasses, their promising applications, and the challenges are outlined. STATEMENT OF SIGNIFICANCE: Bioactive glasses have evolved into a wide range of products used to treat various medical conditions. They are non-equilibrium, non-crystalline materials that have been designed to induce specific biological activity. They can bond to bone and soft tissues and contribute to their regeneration. They are promising in combating pathogens and malignancies by delivering drugs, inorganic therapeutic ions, and heat for magnetic-induced hyperthermia or laser-induced phototherapy. This review addresses each bioactive glass product approved by regulatory agencies for clinical use. A review of the commercialization process is also provided with insight into critical regulatory standards and guidelines for manufacturing. Finally, a critical evaluation of the future of bioactive glass development, applications, and challenges are discussed.

Ultrasound-mediated nano drug delivery for treating cancer: Fundamental physics to future directions

The application of biocompatible nanocarriers in medicine has provided several benefits over conventional treatment methods. However, achieving high treatment efficacy and deep penetration of nanocarriers in tumor tissue is still challenging. To address this, stimuli-responsive nano-sized drug delivery systems (DDSs) are an active area of investigation in delivering anticancer drugs. While ultrasound is mainly used for diagnostic purposes, it can also be applied to affect cellular function and the delivery/release of anticancer drugs. Therapeutic ultrasound (TUS) has shown potential as both a stand-alone anticancer treatment and a method to induce targeted drug release from nanocarrier systems. TUS approaches have been used to overcome various physiological obstacles, including endothelial barriers, the tumor microenvironment (TME), and immunological hurdles. Combining nanomedicine and ultrasound as a smart DDS can increase in situ drug delivery and improve access to impermeable tissues. Furthermore, smart DDSs can perform targeted drug release in response to distinctive TMEs, external triggers, or dual/multi-stimulus. This results in enhanced treatment efficacy and reduced damage to surrounding healthy tissue or organs at risk. Integrating DDSs and ultrasound is still in its early stages. More research and clinical trials are required to fully understand ultrasound's underlying physical mechanisms and interactions with various types of nanocarriers and different types of cells and tissues. In the present review, ultrasound-mediated nano-sized DDS, specifically focused on cancer treatment, is presented and discussed. Ultrasound interaction with nanoparticles (NPs), drug release mechanisms, and various types of ultrasound-sensitive NPs are examined. Additionally, in vitro, in vivo, and clinical applications of TUS are reviewed in light of the critical challenges that need to be considered to advance TUS toward an efficient, secure, straightforward, and accessible cancer treatment. This study also presents effective TUS parameters and safety considerations for this treatment modality and gives recommendations about system design and operation. Finally, future perspectives are considered, and different TUS approaches are examined and discussed in detail. This review investigates drug release and delivery through ultrasound-mediated nano-sized cancer treatment, both pre-clinically and clinically.

Low-dimensional nanomaterials as an emerging platform for cancer diagnosis and therapy

The burden of cancer is increasing, being widely recognized as one of the main reasons for deaths among humans. Despite the tremendous efforts that have been made worldwide to stem the progression and metastasis of cancer, morbidity and mortality in malignant tumors have been clearly rising and threatening human health. In recent years, nanomedicine has come to occupy an increasingly important position in precision oncotherapy, which improves the diagnosis, treatment, and long-term prognosis of cancer. In particular, LDNs with distinctive physicochemical capabilities have provided great potential for advanced biomedical applications, attributed to their large surface area, abundant surface binding sites, and good cellular permeation properties. In addition, LDNs can integrate CT/MR/US/PAI and PTT/PDT/CDT/NDDS into a multimodal theranostic nanoplatform, enabling targeted therapy and efficacy assessments for cancer. This review attempts to concisely summarize the classification and major properties of LDNs. Simultaneously, we particularly emphasize their applications in the imaging, diagnosis, and treatment of cancerous diseases.

Graphene Nanoplatelets-Based Textured Polymeric Fibrous Fabrics for the Next-Generation Devices

Graphene is a 2D crystal composed of carbon atoms in a hexagonal arrangement. From their isolation, graphene nanoplatelets (nCD) have revolutionized material science due to their unique properties, and, nowadays, there are countless applications, including drug delivery, biosensors, energy storage, and tissue engineering. Within this work, nCD were combined with PLA, a widely used and clinically relevant thermoplastic polymer, to produce advanced composite texturized electrospun fabric for the next-generation devices. The electrospinning manufacturing process was set-up by virtue of a proper characterization of the composite raw material and its solution. From the morphological point of view, the nCD addition permitted the reduction of the fiber diameter while the texture allowed more aligned fibers. After that, mechanical features of fabrics were tested at RT and upon heating (40 °C, 69 °C), showing the reinforcement action of nCD mainly in the texturized mats at 40 °C. Finally, mats' degradation in simulated physiological fluid was minimal up to 30 d, even if composite mats revealed excellent fluid-handling capability. Moreover, no toxic impurities and degradation products were pointed out during the incubation. This work gains insight on the effects of the combination of composite carbon-based material and texturized fibers to reach highly performing fabrics.

Insights into stimuli-responsive diselenide bonds utilized in drug delivery systems for cancer therapy

Due to the complexity and particularity of cancer cell microenvironments, redox responsive drug delivery systems (DDSs) for cancer therapy have been extensively explored. Compared with widely reported cancer treatment systems based on disulfide bonds, diselenide bonds have better redox properties and greater anticancer efficiency. In this review, the significance and application of diselenide bonds in DDSs are summarized, and the stimulation sensitivity of diselenide bonds is comprehensively reported. The potential and prospects for the application of diselenide bonds in next-generation anticancer drug treatment systems are extensively discussed.

Physically stimulus-responsive nanoparticles for therapy and diagnosis

Nanoparticles offer numerous advantages in various fields of science, particularly in medicine. Over recent years, the use of nanoparticles in disease diagnosis and treatments has increased dramatically by the development of stimuli-responsive nano-systems, which can respond to internal or external stimuli. In the last 10 years, many preclinical studies were performed on physically triggered nano-systems to develop and optimize stable, precise, and selective therapeutic or diagnostic agents. In this regard, the systems must meet the requirements of efficacy, toxicity, pharmacokinetics, and safety before clinical investigation. Several undesired aspects need to be addressed to successfully translate these physical stimuli-responsive nano-systems, as biomaterials, into clinical practice. These have to be commonly taken into account when developing physically triggered systems; thus, also applicable for nano-systems based on nanomaterials. This review focuses on physically triggered nano-systems (PTNSs), with diagnostic or therapeutic and theranostic applications. Several types of physically triggered nano-systems based on polymeric micelles and hydrogels, mesoporous silica, and magnets are reviewed and discussed in various aspects.

Non-melanoma skin cancers: physio-pathology and role of lipid delivery systems in new chemotherapeutic treatments

Non-melanoma carcinoma has high incidence rates and has two most common subtypes: basal cell carcinoma and squamous cell carcinoma. This type of carcinoma is usually not fatal; however, it can destroy sensory organs such as the nose, ears, and lips. The treatment of these injuries using non-invasive methods is thus strongly recommended. Some treatments for non-melanoma carcinoma are already well defined, such as surgery, cryosurgery, curettage and electrode section, and radiotherapy; however, these conventional treatments cause inflammation and scarring. In the non-surgical treatment of non-melanoma carcinoma, the topical administration of chemotherapeutic drugs contributes for an effective treatment with reduced side effects. However, the penetration of anticancer drugs in the deeper layers of the skin is required. Lipid delivery systems (liposomes, solid lipid nanoparticles, nanostructured lipid carriers) have been developed to overcome epidermal barrier of the skin and to allow the drugs to reach tumor cells. These lipid nanoparticles contribute to control the release profile of the loaded chemotherapeutic drugs, maintaining their stability and increasing death of tumor cells. In this review, the characteristics of non-melanoma carcinoma will be discussed, describing the main existing treatments, together with the contribution of lipid delivery systems as an innovative approach to increase the effectiveness of topical therapies for non-melanoma carcinomas.

Taxanes prodrug-based nanomedicines for cancer therapy

Malignant tumor remains a huge threat to human health and chemotherapy still occupies an important place in clinical tumor treatment. As a kind of potent antimitotic agent, taxanes act as the first-line broad-spectrum cancer drug in clinical use. However, disadvantages such as prominent hydrophobicity, severe off-target toxicity or multidrug resistance lead to unsatisfactory therapeutic effects, which restricts its wider usage. The efficient delivery of taxanes is still quite a challenge despite the rapid developments in biomaterials and nanotechnology. Great progress has been made in prodrug-based nanomedicines (PNS) for cancer therapy due to their outstanding advantages such as high drug loading efficiency, low carrier induced immunogenicity, tumor stimuli-responsive drug release, combinational therapy and so on. Based on the numerous developments in this filed, this review summarized latest updates of taxanes prodrugs-based nanomedicines (TPNS), focusing on polymer-drug conjugate-based nanoformulations, small molecular prodrug-based self-assembled nanoparticles and prodrug-encapsulated nanosystems. In addition, the new trends of tumor stimuli-responsive TPNS were also discussed. Moreover, the future challenges of TPNS for clinical translation were highlighted. We here expect this review will inspire researchers to explore more practical taxanes prodrug-based nano-delivery systems for clinical use.

Current trends of targeted therapy for oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a malignant disease in the world which has a profound effect on human health and life quality. According to tumor stage and pathological diagnosis, OSCC is mainly treated by combinations of surgery, radiotherapy and chemotherapy. However, traditional treatment methods suffer from some limitations, such as systemic toxicity, limited therapeutic effect and drug resistance. With the rapid development of nanotechnology, nanodrug delivery systems (DDSs) and intelligent DDSs have been widely used in targeted therapy for OSCC. Meanwhile, the newly developed therapeutic techniques such as immunotherapy, gene therapy and bionic technology provide the possibility to realize the active targeted therapy. Here, the latest advances of target therapy for OSCC are reviewed, and their therapeutic remarks, current limits and future prospects are also systematically interpreted. It is believed that active and passive targeted therapies have great potentials for clinical transformation and application of OSCC, which will greatly improve human quality of life.

NIR Light-Triggered Quantitative Pulsed Drug Release

Quantitative drug release is important for improving therapeutic efficiency and avoiding side effects. While using long-term delivery system for repeated therapies, it is indispensable but challenging to accurately control the drug dosing. Here, a photocleavable prodrug loaded hydrogel is proposed for near infrared (NIR) light-triggered quantitative pulsed drug release. IR783, a commercially available NIR fluorescent dye, is conjugated with methyl honokiol (mHNK) to give a photocleavable IR783-mHNK prodrug. Injectable glycol chitosan (GC) hydrogel is chosen as a reservoir, in which IR783-mHNK can be efficiently loaded via electrostatic and hydrophobic interactions. Upon 680 nm light-emitting diode (LED) light irradiation, IR783-mHNK cleaves and mHNK is released. Notably, it is found that IR783-mHNK presents synchronous photocleavage-fluorescence bleaching phenomenon. The released amount of mHNK is visible by measuring the residual fluorescent intensity of hydrogel. Quantitative drug release is achieved by controlling irradiation duration and the drug release process is visible by fluorescence imaging. The prodrug-loaded hydrogel shows good stability, minimum leakage and efficient light responsibility both in vitro and in vivo. After light triggering, monitorable quantitative mHNK release and on-demand sleep-promotiing effect are verified in mice without toxicities.

Hollow Mesoporous Manganese Oxides: Application in Cancer Diagnosis and Therapy

The precision, minimal invasiveness, and integration of diagnosis and treatment are critical factors for tumor treatment at the present. Although nanomedicine has shown the potential in tumor precision treatment, nanocarriers with high efficiency, excellent targeting, controlled release, and good biocompatibility still need to be further explored. Hollow mesoporous manganese oxides nanomaterials (HM-MONs), as an efficient drug delivery carrier, have attracted substantial attention in applications of tumor diagnosis and therapy due to their unique properties, such as tumor microenvironment stimuli-responsiveness, prominent catalytic activity, excellent biodegradation, and outstanding magnetic resonance imaging ability. The HM-MONs can not only enhance the therapeutic efficiency but also realize multimodal diagnosis of tumors. Consequently, it is necessary to introduce applications based on HM-MONs in cancer diagnosis and therapy. In this review, the representative progress of HM-MONs in synthesis is discussed. Then, several promising applications in drug delivery, bio-imaging, and bio-detection are highlighted. Finally, the challenges and perspectives of the anticancer applications are summarized, which is expected to provide meaningful guidance on further research.

Semi-Continuous Heterophase Polymerization to Synthesize Poly(methacrylic acid)-Based Nanocomposites for Drug Delivery

The design of nanocomposites with the potential for drug delivery is a topic of great interest. In this work, the synthesis of nanocomposites of poly(methacrylic acid) (PMAA) grafted onto carbon nanotubes (CNTs) functionalized with poly(amidoamine) (PAMAM) dendrimer by semicontinuous heterophase polymerization SHP, at three different methacrylic acid (MAA) dosing rates, is reported. SHP is a polymerization technique poorly used to prepare nanocomposites containing CNTs and has the potential to produce more ordered alkyl methacrylic polymer chains, which could favor the obtaining of a homogenous nanocomposite. For the nanocomposites synthesized, a lowest addition rate monomer-starved condition was reached. Analysis by X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA) demonstrate that functionalized CNTs are grafted onto the PMAA matrix. The ability of prepared nanocomposites to deliver hydrocortisone was evaluated by ultraviolet-visible spectroscopy (UV-Vis). The hydrocortisone release profiles of pure PMAA and of their nanocomposites prepared at the lowest monomer fed rate were fitted with Higuchi and Korsmeyer–Peppas models, successfully. Functionalized CNTs have a crucial role to induce an effective release of hydrocortisone from the prepared nanocomposites.

A biocompatible bismuth based metal-organic framework as efficient light-sensitive drug carrier

The low toxicity and good photo active property endow bismuth based metal-organic frameworks (MOFs) potential candidates for efficient light-sensitive drug carrier. In this work, SU-101, composed of Bi and ellagic acid (EA), is found to display high ciprofloxacin (CIP) loading ratio (85.8%) and controlled CIP release under light illumination (the maximum CIP release ratio is 95.56%). Further investigations suggest that hydrogen bond between the CO group in EA and the -OH group in CIP is responsible for above behavior. Light irradiation decreases the electron density around the CO group in EA, which consequently leads to the broken of the hydrogen bond and therefore the release of CIP. Further investigations suggest that SU-101 is universal for other drugs, such as norfloxacin (NOR), amoxicillin (AMO), tetracycline (TET) and doxorubicinhydrochloride (DOX), since all of them can form hydrogen bond with SU-101. This work suggests that SU-101 holds great potential as efficient light-sensitive drug carrier, and the investigation of other Bi based MOFs as drug carrier is under investigation.

Non-Viral Vectors for Delivery of Nucleic Acid Therapies for Cancer

The research and development of non-viral gene therapy has been extensive over the past decade and has received a big push thanks to the recent successful approval of non-viral nucleic acid therapy products. Despite these developments, nucleic acid therapy applications in cancer have been limited. One of the main causes of this has been the imbalance in development of delivery vectors as compared with sophisticated nucleic acid payloads, such as siRNA, mRNA, etc. This paper reviews non-viral vectors that can be used to deliver nucleic acids for cancer treatment. It discusses various types of vectors and highlights their current applications. Additionally, it discusses a perspective on the current regulatory landscape to facilitate the commercial translation of gene therapy.

Lipid based nanoparticles as a novel treatment modality for hepatocellular carcinoma: a comprehensive review on targeting and recent advances

Liver cancer is considered one of the deadliest diseases with one of the highest disease burdens worldwide. Among the different types of liver cancer, hepatocellular carcinoma is considered to be the most common type. Multiple conventional approaches are being used in treating hepatocellular carcinoma. Focusing on drug treatment, regular agents in conventional forms fail to achieve the intended clinical outcomes. In order to improve the treatment outcomes, utilizing nanoparticles-specifically lipid based nanoparticles-are considered to be one of the most promising approaches being set in motion. Multiple forms of lipid based nanoparticles exist including liposomes, solid lipid nanoparticles, nanostructured lipid carriers, microemulsion, nanoemulsion, phytosomes, lipid coated nanoparticles, and nanoassemblies. Multiple approaches are used to enhance the tumor uptake as well tumor specificity such as intratumoral injection, passive targeting, active targeting, and stimuli responsive nanoparticles. In this review, the effect of utilizing lipidic nanoparticles is being discussed as well as the different tumor uptake enhancement techniques used.

Recent Advancements of Stimuli-Responsive Targeted Liposomal Formulations for Cancer Drug Delivery

Liposomes have gained attention as a well-accepted nanocarrier for several chemotherapeutic drugs and are considered a drug delivery system of choice for a wide range of products. These amphipathic spherical vesicles primarily consist of one or more phospholipid bilayers, showing promise for drug delivery of both hydrophilic and hydrophobic components in addition to unique properties such as biocompatibility, biodegradability, low toxicity, and non-immunogenicity. Recent advances in liposomes are mainly centered on chemical and structural modification with the multifunctional approach to target the cancer cells activating the offensive mechanisms within the proximity of the tumors. Stimuli-responsive liposomes are a precisive approach to deliver and release chemotherapeutic drugs in the tumor site in a controlled fashion, thus reducing damage to normal tissues and preventing the side effects of the conventional chemotherapy regimen. The unique characteristics in the tumor microenvironment facilitate applying an endogenous stimulus (pH, redox potential, or enzymatic activity) to trigger the release of the drug, or external stimulus (heat or light) could be applied to tailor the drug release from liposomes. This review focuses on newer developments in stimuli-sensitive liposomal drug delivery systems designed to apply either exogenous (temperature, light, and magnetic field) or endogenous (pH changes, enzymatic triggers, or redox potential) approaches.

Apoferritin and Dps as drug delivery vehicles: Some selected examples in oncology

BACKGROUND

The ideal nanoparticle should be able to encapsulate either pharmaceutical agents or imaging probes so that it could treat or image clinical tumours by targeting the cancer site efficiently. Further, it would be an added advantage if it demonstrates: small size, built in targeting, biocompatibility and biodegradability. Ferritin, which is an endogenous self-assembling protein, stores iron and plays a role in iron homeostasis. When iron atoms are removed apoferritin (AFt) is formed which consists of a hollow shell where it can be used to load guest molecules. Due to its unique architecture, AFt has been investigated as a versatile carrier for tumour theranostic applications. DNA-binding protein from starved cells (Dps), which also belongs to the ferritin family, is a protein found only in prokaryotes. It is used to store iron and protect chromosomes from oxidative damage; because of its architecture, Dps could also be used as a delivery vehicle.

CONCLUSIONS

Both these nano particles are promising in the field of oncology, especially due to their stability, solubility and biocompatibility features. Further their exterior surface can be modified for better tumour-targeting ability. More studies, are warranted to determine the immunogenicity, biodistribution, and clearance from the body.

GENERAL PERSPECTIVE

This review discusses a few selected examples of the remarkable in vitro and in vivo studies that have been carried out in the recent past with the use of AFt and Dps in targeting and delivery of various pharmaceutical agents, natural products and imaging probes in the field of oncology.

Smart Drug Delivery Strategies for Cancer Therapy

Chemotherapy is one of the most widely used strategies to fight cancer, although it has disadvantages such as accumulation in healthy organs and lack of specificity by cancer cells (non-targeted molecules), among others, resulting in adverse effects on patients that limit the dose or follow-up with the same. However, the treatment can also fail due to the resistance mechanisms that cancer cells have to these agents. Because of these limitations, smart drug delivery strategies have been developed to overcome treatment challenges. These smart drug strategies are made with the aim of passively or actively releasing the drug into the tumor environment, increasing the uptake of the chemotherapeutic agent by the cancer cells, thus reducing the adverse effects on other vital organs. Also, these strategies can be guided with molecules on their surface that interact with the tumor microenvironment or with specific receptors on the cancer cell membrane, thus conferring high affinity. This mini review summarizes advances in the development of drug delivery techniques for cancer treatment, including different smart nanocarriers with single or multifunctional stimuli responsiveness. At the same time, we highlight the toxicity and delivery of these strategies in in vivo models. Despite innovation in smart delivery techniques, there are still biodistribution and customization challenges to be overcome in future research.

Stimuli-responsive drug delivery systems for head and neck cancer therapy

Head and neck cancer (HNC) is among the most common malignancy that has a profound impact on human health and life quality. The treatment for HNC, especially for the advanced cancer is stage-dependent and in need of combined therapies. Various forms of adjuvant treatments such as chemotherapy, phototherapy, hyperthermia, gene therapy have been included in the HNC therapy. However, there are still restrictions with traditional administration such as limited in situ therapeutic effect, systemic toxicity, drug resistance, etc. In recent years, stimuli-responsive drug delivery systems (DDSs) have attracted the great attention in HNC therapy. These intelligent DDSs could respond to unique tumor microenvironment, external triggers or dual/multi stimulus with more specific drug delivery and release, leading to enhanced treatment efficiency and less reduced side effects. In this article, recent studies on stimuli-responsive DDSs for HNC therapy were summarized, which could respond to endogenous and exogenous triggers including pH, matrix metalloproteinases (MMPs), reactive oxygen species (ROS), redox condition, light, magnetic field and multi stimuli. Their therapeutic remarks, current limits and future prospect for these intelligent DDSs were discussed. Furthermore, multifunctional stimuli-responsive DDSs have also been reviewed. With the modification of drug carriers or co-loading with therapeutic agents. Those intelligent DDSs showed more biofunctions such as combined therapeutic effects or integration of diagnosis and treatment for HNC. It is believed that stimuli-responsive drug delivery systems showed great potential for future clinic translation and application for the treatment of HNC.

Recent Progress in Polymeric AIE-Active Drug Delivery Systems: Design and Application

Aggregation-induced emission (AIE) provides a new opportunity to overcome the drawbacks of traditional aggregation-induced quenching of chromophores. The applications of AIE-active fluorophores have spread across various fields. In particular, the employment of AIEgens in drug delivery systems (DDSs) can achieve imaging-guided therapy and pharmacodynamic monitoring. As a result, polymeric AIE-active DDSs are attracting increasing attention due to their obvious advantages, including easy fabrication and tunable optical properties by molecular design. Additionally, the design of polymeric AIE-active DDSs is a promising method for cancer therapy, antibacterial treatment, and pharmacodynamic monitoring, which indeed helps improve the effectiveness of related disease treatments and confirms its potential social importance. Here, we summarize the current available polymeric AIE-active DDSs from design to applications. In the design section, we introduce synthetic strategies and structures of AIE-active polymers, as well as responsive strategies for specific drug delivery. In the application section, typical polymeric AIE-active DDSs used for cancer therapy, bacterial treatment, and drug delivery monitoring are summarized with selected examples to elaborate on their wide applications.

One-Pot Synthesis of Multiple Stimuli-Responsive Magnetic Nanomaterials Based on the Biomineralization of Elastin-like Polypeptides

Synthesis of multiple stimuli-responsive magnetic nanomaterials in a green way remains as a big challenge currently. Herein, temperature-responsive elastin-like polypeptides (ELPs) were designed to involve in the biomimetic mineralization and successfully prepared magnetic nanoparticles (MNPs) (named ELPs-MNPs) with multiple responsiveness (temperature, magnetic, and biomimetic silicification responsiveness) in one pot. ELPs-MNPs were identified as cubic nanomaterials with an average size of about 32 nm and in line with the classic ferromagnetic behavior. Interestingly, ELPs-MNPs show clearly lower critical solution temperature phase behavior with a transition temperature of 36 °C. Moreover, ELPs-MNPs can spontaneously trigger the biosilicification of tetramethyl orthosilicate (TMOS) to entrap themselves into silicon oxide as proved by the Fourier transform infrared spectra (FTIR) and elemental mapping of transmission electron microscopy (TEM), with an average size of about 62 nm. The possible role of ELPs in the biomimetic preparation of the multiple stimuli-responsive MNPs was also addressed. The proposed novel and simple one-pot strategy to synthesize multifunctional nanomaterials with higher effectiveness is the first report for preparing MNPs with multiple stimuli response. This strategy conforms to the concept of green chemistry and will pave a new way for the design of smart biomaterials, which may have great potentials for different fields.

Advances in smart delivery of food bioactive compounds using stimuli-responsive carriers: Responsive mechanism, contemporary challenges, and prospects

Many important food bioactive compounds are plant secondary metabolites that have traditional applications for health promotion and disease prevention. However, the chemical instability and poor bioavailability of these compounds represent major challenges to researchers. In the last decade, therefore, major impetus has been given for the research and development of advanced carrier systems for the delivery of natural bioactive molecules. Among them, stimuli-responsive carriers hold great promise for simultaneously improving stability, bioavailability, and more importantly delivery and on-demand release of intact bioactive phytochemicals to target sites in response to certain stimuli or combination of them (e.g., pH, temperature, oxidant, enzyme, and irradiation) that would eventually enhance therapeutic outcomes and reduce side effects. Hybrid formulations (e.g., inorganic-organic complexes) and multi-stimuli-responsive formulations have demonstrated great potential for future studies. Therefore, this review systematically compiles and assesses the recent advances on the smart delivery of food bioactive compounds, particularly quercetin, curcumin, and resveratrol through stimuli-responsive carriers, and critically reviews their functionality, underlying triggered-release mechanism, and therapeutic potential. Finally, major limitations, contemporary challenges, and possible solutions/future research directions are highlighted. Much more research is needed to optimize the processing parameters of existing formulations and to develop novel ones for lead food bioactive compounds to facilitate their food and nutraceutical applications.

Stimuli-Responsive Nanoplatform-Assisted Photodynamic Therapy Against Bacterial Infections

Bacterial infections are common diseases causing tremendous deaths in clinical settings. It has been a big challenge to human beings because of the antibiotics abuse and the newly emerging microbes. Photodynamic therapy (PDT) is a reactive oxygen species-based therapeutic technique through light-activated photosensitizer (PS). Recent studies have highlighted the potential of PDT as an alternative method of antibacterial treatment for its broad applicability and high efficiency. However, there are some shortcomings due to the low selectivity and specificity of PS. Growing evidence has shown that drug delivery nanoplatforms have unique advantages in enhancing therapeutic efficacy of drugs. Particularly, stimuli-responsive nanoplatforms, as a promising delivery system, provide great opportunities for the effective delivery of PS. In the present mini-review, we briefly introduced the unique microenvironment in bacterial infection tissues and the application of PDT on bacterial infections. Then we review the stimuli-responsive nanoplatforms (including pH-, enzymes-, redox-, magnetic-, and electric-) used in PDT against bacterial infections. Lastly, some perspectives have also been proposed to further promote the future developments of antibacterial PDT.

Stimuli-responsive graphene oxide and methotrexate-loaded magnetic nanoparticles for breast cancer-targeted therapy

Aim: Nanocomposites of graphene oxide (GO) loaded with PEGylated superparamagnetic iron oxide nanoparticles and grafted with methotrexate and stimuli-responsive linkers (GO-SPION-MTX) were developed for photothermal and chemotherapy of breast cancer. Methods: PEGylated SPIONs were synthesized and conjugated with chemotherapeutic targeting agent MTX, which were then loaded on GO to prepare GO-SPION-MTX nanocomposites. To evaluate the photothermal effect of the nanocomposites, they were examined in breast cancer cell lines with low doses of near-infrared (NIR) laser radiation with/without acetazolamide. Results: The GO-SPION-MTX nanocomposites were found to be internalized by the folate-receptor-positive cancer cells and induce high cytotoxicity on exposure to NIR laser rays. Conclusion: Our findings suggest that the GO-SPION-MTX nanocomposite can potentially be used as a multimodal nanomedicine/theranostic against breast cancer.

Application of glutathione depletion in cancer therapy: Enhanced ROS-based therapy, ferroptosis, and chemotherapy

Glutathione (GSH) is an important member of cellular antioxidative system. In cancer cells, a high level of GSH is indispensable to scavenge excessive reactive oxygen species (ROS) and detoxify xenobiotics, which make it a potential target for cancer therapy. Plenty of studies have shown that loss of intracellular GSH makes cancer cells more susceptible to oxidative stress and chemotherapeutic agents. GSH depletion has been proved to improve the therapeutic efficacy of ROS-based therapy (photodynamic therapy, sonodynamic therapy, and chemodynamic therapy), ferroptosis, and chemotherapy. In this review, various strategies for GSH depletion used in cancer therapy are comprehensively summarized and discussed. First, the functions of GSH in cancer cells are analyzed to elucidate the necessity of GSH depletion in cancer therapy. Then, the synthesis and metabolism of GSH are briefly introduced to bring up some crucial targets for GSH modulation. Finally, different approaches to GSH depletion in the literature are classified and discussed in detail according to their mechanisms. Particularly, functional materials with GSH-consuming ability based on nanotechnology are elaborated due to their unique advantages and potentials. This review presents the ingenious application of GSH-depleting strategy in cancer therapy for improving the outcomes of various therapeutic regimens, which may provide useful guidance for designing intelligent drug delivery system.

Drug Delivery by Ultrasound-Responsive Nanocarriers for Cancer Treatment

Conventional cancer chemotherapies often exhibit insufficient therapeutic outcomes and dose-limiting toxicity. Therefore, there is a need for novel therapeutics and formulations with higher efficacy, improved safety, and more favorable toxicological profiles. This has promoted the development of nanomedicines, including systems for drug delivery, but also for imaging and diagnostics. Nanoparticles loaded with drugs can be designed to overcome several biological barriers to improving efficiency and reducing toxicity. In addition, stimuli-responsive nanocarriers are able to release their payload on demand at the tumor tissue site, preventing premature drug loss. This review focuses on ultrasound-triggered drug delivery by nanocarriers as a versatile, cost-efficient, non-invasive technique for improving tissue specificity and tissue penetration, and for achieving high drug concentrations at their intended site of action. It highlights aspects relevant for ultrasound-mediated drug delivery, including ultrasound parameters and resulting biological effects. Then, concepts in ultrasound-mediated drug delivery are introduced and a comprehensive overview of several types of nanoparticles used for this purpose is given. This includes an in-depth compilation of the literature on the various in vivo ultrasound-responsive drug delivery systems. Finally, toxicological and safety considerations regarding ultrasound-mediated drug delivery with nanocarriers are discussed.

Graphene-based nanomaterials for breast cancer treatment: promising therapeutic strategies

Breast cancer is the most common malignancy in women, and its incidence increases annually. Traditional therapies have several side effects, leading to the urgent need to explore new smart drug-delivery systems and find new therapeutic strategies. Graphene-based nanomaterials (GBNs) are potential drug carriers due to their target selectivity, easy functionalization, chemosensitization and high drug-loading capacity. Previous studies have revealed that GBNs play an important role in fighting breast cancer. Here, we have summarized the superior properties of GBNs and modifications to shape GBNs for improved function. Then, we focus on the applications of GBNs in breast cancer treatment, including drug delivery, gene therapy, phototherapy, and magnetothermal therapy (MTT), and as a platform to combine multiple therapies. Their advantages in enhancing therapeutic effects, reducing the toxicity of chemotherapeutic drugs, overcoming multidrug resistance (MDR) and inhibiting tumor metastasis are highlighted. This review aims to help evaluate GBNs as therapeutic strategies and provide additional novel ideas for their application in breast cancer therapy.

Sialic Acid-Modified Nanoparticles-New Approaches in the Glioma Management-Perspective Review

The cell surface is covered by a dense and complex network of glycans attached to the membrane proteins and lipids. In gliomas, the aberrant sialylation, as the final stage of glycosylation, is an important regulatory mechanism of malignant cell behavior and correlates with worse prognosis. Better understanding of the role of sialylation in cellular and molecular processes opens a new way in the development of therapeutic tools for human brain tumors. According to the recent clinical observation, the cellular heterogeneity, activity of brain cancer stem cells (BCSCs), immune evasion, and function of the blood–brain barrier (BBB) are attractive targets for new therapeutic strategies. In this review, we summarize the importance of sialic acid-modified nanoparticles in brain tumor progression.

An understanding of mitochondria and its role in targeting nanocarriers for diagnosis and treatment of cancer

Nanotechnology has changed the entire paradigm of drug targeting and has shown tremendous potential in the area of cancer therapy due to its specificity. In cancer, several targets have been explored which could be utilized for the better treatment of disease. Mitochondria, the so-called powerhouse of cell, portrays significant role in the survival and death of cells, and has emerged as potential target for cancer therapy. Direct targeting and nanotechnology based approaches can be tailor-made to target mitochondria and thus improve the survival rate of patients suffering from cancer. With this backdrop, in present review, we have reemphasized the role of mitochondria in cancer progression and inhibition, highlighting the different targets that can be explored for targeting of disease. Moreover, we have also summarized different nanoparticulate systems that have been used for treatment of cancer via mitochondrial targeting.

Azo modified hyaluronic acid based nanocapsules: CD44 targeted, UV-responsive decomposition and drug release in liver cancer cells

Herein, we demonstrate a novel UV-induced decomposable nanocapsule of natural polysaccharide (HA-azo/PDADMAC). The nanocapsules are fabricated based on layer-by-layer co-assembly of anionic azobenzene functionalized hyaluronic acid (HA-azo) and cationic poly diallyl dimethylammonium chloride (PDADMAC). When the nanocapsules are exposed to 365 nm light, ultraviolet photons can trigger the photo-isomerization of azobenzene groups in the framework. The nanocapsules could decompose from large-sized nanocapsules to small fragments. Due to their optimized original size (~180 nm), the nanocapsules can effectively avoid biological barriers, provide a long blood circulation and achieve high tumor accumulation. It can fast eliminate nanocapsules from tumor and release the loaded drugs for chemotherapy after UV-induced dissociation. Besides, HA is an endogenous polysaccharide that shows intrinsic targetability to CD44 receptors on surface of cancer cells. The intracellular experiment shows that the HA-azo/PDADMAC nanocapsules with CD44 targeting ability and UV-controlled intracellular drug release are promising for cancer chemotherapy.

Synthesis and surface modification of mesoporous metal-organic framework (UiO-66) for efficient pH-responsive drug delivery and lung cancer treatment

This paper applied mesoporous metal-organic frameworks (MOFs) of UiO-66 particles for pH-responsive doxorubicin (DOX) delivery and cancer treatment. Mesoporous structured UiO-66 MOFs were synthesized, and carboxymethylcellulose (CMC) was loaded for sensitive pH response and also as a linker to encapsulate the chemotherapeutic drug of DOX. The composite of UiO-66/CMC@DOX was synthesized, and the loading capacity was as high as 45μg DOX per mg of the carrier. The structure and crystalization of the UiO-66 MOFs were determined by the Transmitting Electron Microscope (TEM) and x-ray diffraction methods, while the loading of CMC and DOX was inspected by Fourier Transform InfraRed (FT-IR) and UV-vis spectroscopy. The DOX release from UiO-66/CMC@DOX was tested under different pH at 37 °C. The DOX accumulative release could reach 78% under the pH of 5. A lower pH was more favorable for DOX release due to the CMC shrinking and higher DOX solubility in an acidic environment. The cytotoxicity study indicated that, under the DOX concentration of 4μg ml^-1, the A549 cell (Lung Carcinoma Cell Line) viability of UiO-66/CMC was 28%, which was lower than that from free DOX solution (47%). UiO-66 MOFs were demonstrated to be an efficient drug delivery carrier for chemotherapeutic drug and release.