Realizing the clinical potential of cancer nanotechnology by minimizing toxicologic and targeted delivery concerns

Nanozymes and their biomolecular conjugates as next-generation antibacterial agents: A comprehensive review

Antimicrobial resistance (AMR), the ability of bacterial species to develop resistance against exposed antibiotics, has gained immense global attention in the past few years. Bacterial infections are serious health concerns affecting millions of people annually worldwide. Therefore, developing novel antibacterial agents that are highly effective and avoid resistance development is imperative. Among various strategies, recent developments in nanozyme technology have shown promising results as antibacterials in several antibiotic-sensitive and resistant bacterial species. Nanozymes offer several advantages over corresponding natural enzymes, such as inexpensive, stable, multifunctional, tunable catalytic properties, etc. Although the use of nanozymes as antibacterial agents has provided promising results, the specific biomolecule-conjugated nanozymes have shown further improvement in catalytic performance and associated antibacterial efficacy. The exclusive design of functional nanozymes with theranostic potential is found to simultaneously inhibit the growth and image of AMR bacterial species. This review comprehensively summarizes the history of nanozymes, their classification, biomolecules conjugated nanozyme, and their mechanism of enzyme-mimetic activity and associated antibacterial activity in antibiotic-sensitive and resistant species. The futureneeds to effectively engineer the existing or new nanozymes to curb AMR have also been discussed.

Nanomedicine as a multimodal therapeutic paradigm against cancer: on the way forward in advancing precision therapy

Recent years have witnessed dramatic improvements in nanotechnology-based cancer therapeutics, and it continues to evolve from the use of conventional therapies (chemotherapy, surgery, and radiotherapy) to increasingly multi-complex approaches incorporating thermal energy-based tumor ablation (e.g. magnetic hyperthermia and photothermal therapy), dynamic therapy (e.g. photodynamic therapy), gene therapy, sonodynamic therapy (e.g. ultrasound), immunotherapy, and more recently real-time treatment efficacy monitoring (e.g. theranostic MRI-sensitive nanoparticles). Unlike monotherapy, these multimodal therapies (bimodal, i.e., a combination of two therapies, and trimodal, i.e., a combination of more than two therapies) incorporating nanoplatforms have tremendous potential to improve the tumor tissue penetration and retention of therapeutic agents through selective active/passive targeting effects. These combinatorial therapies can correspondingly alleviate drug response against hypoxic/acidic and immunosuppressive tumor microenvironments and promote/induce tumor cell death through various multi-mechanisms such as apoptosis, autophagy, and reactive oxygen-based cytotoxicity, e.g., ferroptosis, etc. These multi-faced approaches such as targeting the tumor vasculature, neoangiogenic vessels, drug-resistant cancer stem cells (CSCs), preventing intra/extravasation to reduce metastatic growth, and modulation of antitumor immune responses work complementary to each other, enhancing treatment efficacy. In this review, we discuss recent advances in different nanotechnology-mediated synergistic/additive combination therapies, emphasizing their underlying mechanisms for improving cancer prognosis and survival outcomes. Additionally, significant challenges such as CSCs, hypoxia, immunosuppression, and distant/local metastasis associated with therapy resistance and tumor recurrences are reviewed. Furthermore, to improve the clinical precision of these multimodal nanoplatforms in cancer treatment, their successful bench-to-clinic translation with controlled and localized drug-release kinetics, maximizing the therapeutic window while addressing safety and regulatory concerns are discussed. As we advance further, exploiting these strategies in clinically more relevant models such as patient-derived xenografts and 3D organoids will pave the way for the application of precision therapy.

Antioxidant nanozymes as next-generation therapeutics to free radical-mediated inflammatory diseases: A comprehensive review

Recent developments in exploring the biological enzyme mimicking properties in nanozymes have opened a separate avenue, which provides a suitable alternative to the natural antioxidants and enzymes. Due to high and tunable catalytic activity, low cost of synthesis, easy surface modification, and good biocompatibility, nanozymes have garnered significant research interest globally. Several inorganic nanomaterials have been investigated to exhibit catalytic activities of some of the key natural enzymes, including superoxide dismutase (SOD), catalase, glutathione peroxidase, peroxidase, and oxidase, etc. These nanozymes are used for diverse biomedical applications including therapeutics, imaging, and biosensing in various cells/tissues and animal models. In particular, inflammation-related diseases are closely associated with reactive oxygen and reactive nitrogen species, and therefore effective antioxidants could be excellent therapeutics due to their free radical scavenging ability. Although biological enzymes and other artificial antioxidants could perform well in scavenging the reactive oxygen and nitrogen species, however, suffer from several drawbacks such as the requirement of strict physiological conditions for enzymatic activity, limited stability in the environment beyond their optimum pH and temperature, and high cost of synthesis, purification, and storage make then unattractive for broad-spectrum applications. Therefore, this review systematically and comprehensively presents the free radical-mediated evolution of various inflammatory diseases (inflammatory bowel disease, mammary gland fibrosis, and inflammation, acute injury of the liver and kidney, mammary fibrosis, and cerebral ischemic stroke reperfusion) and their mitigation by various antioxidant nanozymes in the biological system. The mechanism of free radical scavenging by antioxidant nanozymes under in vitro and in vivo experimental models and catalytic efficiency comparison with corresponding natural enzymes has also been presented.

Nanotherapeutic Approach to Delivery of Chemo- and Gene Therapy for Organ-Confined and Advanced Castration-Resistant Prostate Cancer

Treatments for late-stage prostate cancer (CaP) have not been very successful. Frequently, advanced CaP progresses to castration-resistant prostate cancer (CRPC), with 50#37;-70% of patients developing bone metastases. CaP with bone metastasis-associated clinical complications and treatment resistance presents major clinical challenges. Recent advances in the formulation of clinically applicable nanoparticles (NPs) have attracted attention in the fields of medicine and pharmacology with applications to cancer and infectious and neurological diseases. NPs have been rendered biocompatible, pose little to no toxicity to healthy cells and tissues, and are engineered to carry large therapeutic payloads, including chemo- and genetic therapies. Additionally, if required, targeting specificity can be achieved by chemically coupling aptamers, unique peptide ligands, or monoclonal antibodies to the surface of NPs. Encapsulating toxic drugs within NPs and delivering them specifically to their cellular targets overcomes the problem of systemic toxicity. Encapsulating highly labile genetic therapeutics such as RNA within NPs provides a protective environment for the payload during parenteral administration. The loading efficiencies of NPs have been maximized while the controlled their therapeutic cargos has been released. Theranostic ("treat and see") NPs have developed combining therapy with imaging capabilities to provide real-time, image-guided monitoring of the delivery of their therapeutic payloads. All of these NP accomplishments have been applied to the nanotherapy of late-stage CaP, offering a new opportunity for a previously dismal prognosis. This article gives an update on current developments in the use of nanotechnology for treating late-stage, castration-resistant CaP.

Surface decorated quantum dots: Synthesis, properties and role in herbal therapy

Quantum dots are the serendipitous outcome of materials research. It is the tiny carbonaceous nanoparticles with diameters ranging from 1 to 10 nm. This review is a brief discussion of the synthesis, properties, and biomedical applicability of quantum dots, especially in herbal therapy. As quantum dots are highly polar, they can be surface decorated with several kinds of polar functionalities, such as polymeric molecules, small functional molecules, and so on. The review also consists of the basic physical and optical properties of quantum dots and their excitation-dependent properties in the application section. We focus on therapeutics, where quantum dots are used as drugs or imaging probes. Nanoprobes for several diagnostics are quite new in the biomedical research domain. Quantum dot-based nanoprobes are in high demand due to their excellent fluorescence, non-bleaching nature, biocompatibility, anchoring feasibility for several analytes, and fast point-of-care sensibility. Lastly, we also included a discussion on quantum dot-based drug delivery as phytomedicine.

3D-Printed Oxygen-Carrying Nanocomposite Hydrogels for Enhanced Cell Viability under Hypoxic and Normoxic Conditions

Insufficient and heterogeneous oxygen (O₂) distribution within engineered tissues results in hypoxic conditions. Hypoxia is one of the characteristics of solid tumors. To date, very few studies have used an O₂-deliverable injectable hydrogel for cancer treatment under hypoxic conditions. In this field, we describe a new O₂-carrying nanomaterial and an injectable nanocomposite hydrogel (PMOF and AlgL-PMOF, respectively) that can provide extended oxygen levels for cell survival under hypoxia. Particularly, PMOF and AlgL-PMOF enhance cell viability under hypoxic and normoxic cell culturing conditions. Moreover, sustained oxygen availability in the presence of an anticancer drug within the 3D network of AlgL-PMOF results in a decrease in the viability of malignant and immortal cells, while the viability of healthy cells increases.

Research progress on the biomedical application of microalgae

Microalgae is an easy-to-obtain natural biological material with many varieties and abundant natural reserves. Microalgae are rich in natural fluorescein, which can be used as a contrast agent for fluorescence imaging and photoacoustic imaging for medical imaging. With its active surface, microalgae can effectively adsorb functional molecules, metal elements, etc., and have good application prospects in the field of drug delivery. Microalgae can generate oxygen through photosynthesis to increase local oxygen concentration, reverse local hypoxia to enhance the efficacy of hypoxic tumors and promote wound healing. In addition, microalgae have good biocompatibility, and different administration methods have no obvious toxicity. This paper reviews the research progress on the biomedical application of microalgae in bioimaging, drug delivery, hypoxic tumor treatment, wound healing.

New Strategies for Safe Cancer Therapy Using Electrospun Nanofibers: A Short Review

Electrospun nanofibers regarding their special features, including high drug loading capacity, high surface to volume area, flexibility, and ease of production and operation, are of great interest for being used in tissue engineering, and drug delivery approaches. In this context, several studies have been done for the production of biodegradable and biocompatible scaffolds containing different anticancer agents for fighting with solid tumors. Surprisingly, these scaffolds are able to deliver different combinations of drugs and agents, such as nanoparticles and release them in a time dependent manner. Here in this review, we summarize the principles of electrospinning and their uses in entrapment of drugs and anti-proliferative agents suitable for cancer therapy. The latest studies performed on treating cancer using electrospinning are mentioned and their advantages and disadvantages over conventional treatment methods are discussed.

Two-Photon Fluorescent Nanomaterials and Their Applications in Biomedicine

In recent years, two-photon excited (TPE) materials have attracted great attentions because of their excellent advantages over conventional one-photon excited (OPE) materials, such as deep tissue penetration, three-dimensional spatial selectivity and low phototoxicity. Also, they have been widely applied in lots of field, such as biosensing, imaging, photo-catalysis, photoelectric conversion, and therapy. In this article, we review recent advances in vibrant topic of two-photon fluorescent nanomaterials, including organic molecules, quantum dots (QDs), carbon dots (CDs) and metal nanoclus-ters (MNCs). The optical properties, synthetic methods and important applications of TPE nanomaterials in biomedical field, such as biosensing, imaging and therapy are introduced. Also, the probable challenges and perspectives in the forthcoming development of two-photon fluorescent nanomaterials are addressed.

PSMA conjugated combinatorial liposomal formulation encapsulating genistein and plumbagin to induce apoptosis in prostate cancer cells

Although the biomedical sciences have achieved tremendous success in developing novel approaches to managing prostate cancer, this disease remains one of the major health concerns among men worldwide. Liposomal formulations of single drugs have shown promising results in cancer treatment; however, the use of multi drugs has shown a better therapeutic index than individual drugs. The identification of cancer-specific receptors has added value to design targeted drug delivering nanocarriers. We have developed genistein and plumbagin co-encapsulating liposomes (∼120 nm) with PSMA specific antibodies to target prostate cancer cells selectively in this work. These liposomes showed >90 % decrease in PSMA expressing prostate cancer cell proliferation without any appreciable toxicity to healthy cells and human red blood cells. Release of plumbagin and genistein was found to decrease the expression of PI3/AKT3 signaling proteins and Glut-1 receptors (inhibited glucose uptake and metabolism), respectively. The decrease in migration potential of cells and induced apoptosis established the observed anti-proliferative effect in prostate cancer cell lines. The discussed strategy of developing novel, non-toxic, and PSMA specific antibody conjugated liposomes carrying genistein and plumbagin drugs may also be used for encapsulating other drugs and inhibit the growth of different types of cancers.

Co-delivery of AKT3 siRNA and PTEN Plasmid by Antioxidant Nanoliposomes for Enhanced Antiproliferation of Prostate Cancer Cells

Globally, prostate cancer is the fifth major cancer type and the second leading cause of cancer-related death in men. In 2018, about 1.3 million prostate cancer cases were reported worldwide. It is reported that loss of PTEN (tumor suppressor gene) expression leads to hyperactivation of the PI3K/AKT pathway and thus induces uncontrolled cell proliferation. Loss or mutation in regular PTEN expression is reported to occur in ∼30% of primary prostate cancer cases and ∼65% of metastatic cancer cases. Restoring the PTEN expression could inhibit the PI3K/AKT/mTOR signaling pathway, thus avoid the growth of prostate cancer cells. In this work, we have synthesized a multifunctional nanoliposomal formulation incorporating PTEN plasmid, AKT3 siRNA, and antioxidant cerium oxide nanoparticles (CeNPs). The nanoliposomes were able to successfully internalize in prostate cancer (PC-3) cells, restore the expression of PTEN protein, and knock down AKT3 mRNA. Further, the multifunctional nanoliposomes induce DNA damage and apoptosis in prostate cancer cells. The investigation of the PI3K/AKT/mTOR signaling pathway revealed that PTEN protein and apoptosis-specific proteins are overexpressed, leading to the inhibition of oncoproteins and, thus, prostate cancer.

Engineered algae: A novel oxygen-generating system for effective treatment of hypoxic cancer

Microalgae, a naturally present unicellular microorganism, can undergo light photosynthesis and have been used in biofuels, nutrition, etc. Here, we report that engineered live microalgae can be delivered to hypoxic tumor regions to increase local oxygen levels and resensitize resistant cancer cells to both radio- and phototherapies. We demonstrate that the hypoxic environment in tumors is markedly improved by in situ-generated oxygen through microalgae-mediated photosynthesis, resulting in notably radiotherapeutic efficacy. Furthermore, the chlorophyll from microalgae produces reactive oxygen species during laser irradiation, further augmenting the photosensitizing effect and enhancing tumor cell apoptosis. Thus, the sequential combination of oxygen-generating algae system with radio- and phototherapies has the potential to create an innovative treatment strategy to improve the outcome of cancer management. Together, our findings demonstrate a novel approach that leverages the products of photosynthesis for treatment of tumors and provide proof-of-concept evidence for future development of algae-enhanced radio- and photodynamic therapy.

Recent strategies towards the surface modification of liposomes: an innovative approach for different clinical applications

Liposomes are very useful biocompatible tools used in diverse scientific disciplines, employed for the vehiculation and delivery of lipophilic, ampiphilic or hydrophilic compounds. Liposomes have gained the importance as drug carriers, as the drugs alone have limited targets, higher toxicity and develop resistance when used in higher doses. Conventional liposomes suffer from several drawbacks like encapsulation inefficiencies and partially controlled particle size. The surface chemistry of liposome technology started from simple conventional vesicles to second generation liposomes by modulating their lipid composition and surface with different ligands. Introduction of polyethylene glycol to lipid anchor was the first innovative strategy which increased circulation time, delayed clearance and opsonin resistance. PEGylated liposomes have been found to possess higher drug loading capacity up to 90% or more and some drugs like CPX-1 encapsuled in such liposomes have increased the disease control up to 73% patients suffering from colorectal cancer. The surface of liposomes have been further liganded with small molecules, vitamins, carbohydrates, peptides, proteins, antibodies, aptamers and enzymes. These advanced liposomes exhibit greater solubility, higher stability, long-circulating time and specific drug targeting properties. The immense utility and demand of surface modified liposomes in different areas have led their way to the modern market. In addition to this, the multi-drug carrier approach of targeted liposomes is an innovative method to overcome drug resistance while treating ceratin tumors. Presently, several second-generation liposomal formulations of different anticancer drugs are at various stages of clinical trials. This review article summarizes briefly the preparation of liposomes, strategies of disease targeting and exclusively the surface modifications with different entities and their clinical applications especially as drug delivery system.

Magnetic Nanoparticles: Current Trends and Future Aspects in Diagnostics and Nanomedicine

Background:

Biomedical applications of Magnetic Nanoparticles (MNPs) are creating a major impact on disease diagnosis and nanomedicine or a combined platform called theranostics. A significant progress has been made to engineer novel and hybrid MNPs for their multifunctional modalities such as imaging, biosensors, chemotherapeutic or photothermal and antimicrobial agents. MNPs are successfully applied in biomedical applications due to their unique and tunable properties such as superparamagnetism, stability, and biocompatibility. Approval of ferumoxytol (feraheme) for MRI and the fact that several Superparamagnetic Iron Oxide Nanoparticles (SPIONs) are currently undergoing clinical trials have paved a path for future MNPs formulations. Intensive research is being carried out in designing and developing novel nanohybrids for multiple applications in nanomedicine.

Objective:

The objective of the present review is to summarize recent developments of MNPs in imaging modalities like MRI, CT, PET and PA, biosensors and nanomedicine including their role in targeting and drug delivery. Relevant theory and examples of the use of MNPs in these applications have been cited and discussed to create a thorough understanding of the developments in this field.

Conclusion:

MNPs have found widespread use as contrast agents in imaging modalities, as tools for bio-sensing, and as therapeutic and theranostics agents. Multiple formulations of MNPs are in clinical testing and may be accepted in clinical settings in near future.

Anti-leishmanial Nanotherapeutics: A Current Perspective

Background:

Leishmaniasis is a dreaded disease caused by protozoan parasites belonging to the genus Leishmania which results in significant morbidity and mortality worldwide. There are no vaccines available currently for the treatment of Leishmaniasis and chemotherapy still remains the mainstay for anti-leishmanial therapeutics. However, toxicity, reduced bioavailability, high cost and chemoresistance are the principal problems which limit the use of the available drugs. In this context, anti-leishmanial nanotherapeutics may show the way for effective treatment of this dreaded disease.

Methods:

We carried out extensive literature search of bibliographic database using keywords strictly within the scope of the present study for peer reviewed research articles. We focused specifically on articles related to the application of nanotechnology in drug development, drug delivery and vaccine delivery for anti-leishmanial therapeutics.

Results:

This study shows the immense potential of the application of nanotechnology in the field of anti-leishmanial therapeutics. This will aid the targeted delivery of different drugs which is expected to increase the bioavailability, reduce toxicity and also address the problem of chemoresistance.

Conclusion:

We surmise that exciting research in the field of anti-leishmanial nanotherapeutics is already showing the promise for effective applicability. Though direct use of nanoparticles as therapeutic agents does not seem to be a good option, the application of nanotechnology in this field for vaccine development is still in its early days. The nano based drug delivery system for anti-leishmanial therapeutics has evolved considerably over the past ten years and holds the potential to drastically change the landscape of anti-leishmanial therapeutics.

Nanodrugs used in cancer therapy

Cancer despite the introduction of new targeted therapy remains for many patients a fatal disease. Nanotechnology in cancer medicine has emerged as a promising approach to defeat cancer. Targeted delivery of anti-cancer drugs by different nanosystems promises enhanced drug efficacy, selectivity, better safety profile and reduced systemic toxicity. The article presents an overview of recent developments in cancer nanomedicine. We focus on approved anti-cancer medical products and on the results of clinical studies, highlighting that liposomal and micellar cytostatics or albumin-based nanoparticles have less side effects and are more efficient than "free" drugs. In addition, we discuss results of in vitro and in vivo preclinical studies with lipid, inorganic and polymer nanosystems loaded by anticancer drugs which according to our meaning are important for development of new nanodrugs. Pharmacokinetic characteristics of nanodrugs are discussed and characterization of major nanotechnology systems used for cancer nanomedicine is presented.

Redox-dependent catalase mimetic cerium oxide-based nanozyme protect human hepatic cells from 3-AT induced acatalasemia

Recently, CeNPs have emerged as an effective therapeutic agent due to their redox-active nature encompassing the ability to switch between +4 or +3 oxidation states of surface "Ce" atoms. CeNPs with predominantly high Ce +4 oxidation state have been shown to exhibit biological catalase enzyme-like activity. Catalase enzyme is naturally present in mammalian cells and facilitates the protection from reactive oxygen species (ROS), generated due to decomposition of hydrogen peroxide (H₂O₂). Inactivation of cellular catalase enzyme is known to cause several diseases such as acatalasemia, type 2 diabetes mellitus, and vitiligo. In this study, we have artificially inhibited the activity of cellular catalase enzyme from human liver cells (WRL-68) using 3-Amino-1,2,4-Triazole (3-AT). Further, CeNPs was used for imparting protective effect against the deleterious effects of elevated cellular H₂O₂ concentration. Our results suggest that CeNPs (+4) can protect hepatic cells from cytotoxicity and genetic damage from the high concentrations of H₂O₂ in the absence of functional catalase enzyme. CeNPs were efficiently internalized in WRL-68 cells and effectively scavenge the free radicals generated due to elevated H₂O₂ inside the cells. Additionally, CeNPs were also shown to protect cells from undergoing early apoptosis and DNA damage induced due to the 3-AT exposure. Moreover, CeNPs did not elicit the natural antioxidant defense system of the cells even in the absence of functional catalase enzyme, suggesting that the observed protection was due to the H₂O₂ degradation activity of CeNPs (+4). Our finding substantiates the reinforcement of CeNPs as pharmacological agents for the treatment of diseases related to nonfunctional biological catalase enzyme in the mammalian cells.

Molecular simulation and in vitro evaluation of chitosan nanoparticles as drug delivery systems for the controlled release of anticancer drug cytarabine against solid tumours

The present work is an attempt to integrate the molecular simulation studies with in vitro cytotoxicity of cytarabine-loaded chitosan nanoparticles and exploring the potential of this formulation as therapeutics for treating solid tumours. The molecular simulation was performed using GROMACS v5.4 in which, chitosan polymer (CHT; six molecules) was used to study the encapsulation and release of a single molecule of cytarabine. Root Mean Square Deviation (RMSD) of the Cα atom of cytarabine (CBR) molecule shows that CBR starts to diffuse out of the CHT polymer binding pocket around 10.2 ns, indicated by increased fluctuation of RMSD at pH 6.4, while the drug diffusion is delayed at pH 7.4 and starts diffusing around 17.5 ns. Cytarabine-loaded chitosan nanoparticles (CCNP), prepared by ionic gelation method were characterized for encapsulation efficiency, particle size and morphology, zeta potential, crystallinity and drug release profile at pH 6.4 and 7.4. CCNPs showed 64% encapsulation efficiency with an average diameter of 100 nm and zeta potential of + 53.9 mV. It was found that cytarabine existed in amorphous state in nanoformulation. In vitro release studies showed 70% cytarabine was released from the chitosan-based nanoformulation release at pH 6.4, which coincides with the pH of tumour microenvironment. Cytotoxicity against breast cancer cell line (MCF 7) was higher for nanoformulation compared to free cytarabine. Haemocompatibility studies showed that chitosan-based nanoformulation is safe, biocompatible and nonhaemolytic in nature; hence, can be used as a safe drug delivery system. Taken together, our study suggests that chitosan nanoformulation would be an effective strategy for the pH-dependent release of cytarabine against solid tumours and might impart better therapeutic efficiency.

Prostate cancer: updates on current strategies for screening, diagnosis and clinical implications of treatment modalities

Prostate cancer is the most common cancer in men by way of diagnosis and a leading cause of cancer-related deaths. Early detection and intervention remains key to its optimum clinical management. This review provides the most updated information on the recent methods of prostate cancer screening, imaging and treatment modalities. Wherever possible, clinical trial data has been supplemented to provide a comprehensive overview of current prostate cancer research and development. Considering the recent success of immunotherapy in prostate cancer, we discuss cell, DNA and viruses based, as well as combinatorial immunotherapeutic strategies in detail. Furthermore, the potential of nanotechnology is increasingly being realized, especially in prostate cancer research, and we provide an overview of nanotechnology-based strategies, with special emphasis on nanotheranostics and multifunctional nanoconstructs. Understanding these recent developments is critical to the design of future therapeutic strategies to counter prostate cancer.

Multifunctional antioxidant nanoliposome-mediated delivery of PTEN plasmids restore the expression of tumor suppressor protein and induce apoptosis in prostate cancer cells

Prostate cancer is the second leading cause of cancer death in men and about one in nine will be diagnosed in his lifetime. Loss of PTEN has been considered as one of the major factors leading to the origin of prostate cancer through modulating PI3K/AKT signaling pathways. In this study, we have prepared a multifunctional antioxidant nanoliposome containing PTEN plasmid and cerium oxide nanoparticles (CeNPs). The efficient delivery of PTEN plasmid to human prostate cancer cells (PC-3) leads to restoration of the expression of lost PTEN protein in the cell cytoplasm. The delivered superoxide dismutase (SOD)-mimetic CeNPs were also found to decrease the cytoplasmic free radical levels in prostate cancer cells. The above two activities induced DNA fragmentation and micronucleus formation in prostate cancer cells. Furthermore, it was also found that these multifunctional antioxidant nanoliposomes inhibit the PI3K/AKT signaling pathway to negatively regulate the cell viability of prostate cancer cells. The mRNA expression pattern of other relevant proteins predominantly involved in cancer cell proliferation and apoptosis suggested that the high PTEN expression could control the synthesis of oncogenic proteins. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 3152-3164, 2018.

Liposome encapsulation of doxorubicin and celecoxib in combination inhibits progression of human skin cancer cells

Therapeutic agents aimed at inhibiting a single molecular target have not been successful in cancer therapy, but rather they impart resistance. However, multi-target inhibitors have shown promising results in circumventing the development of resistance and inducing apoptosis in cancer cells/tissues. In this study, we encapsulated doxorubicin and celecoxib in a single liposome at a ratio of 1:10. These dual drug-encapsulated liposomes showed excellent anticancer activity compared to individually encapsulated liposomes. The expression of key proteins such as AKT and COX-2 was suppressed, which suggests that doxorubicin and celecoxib synergistically inhibit multiple key signaling pathways.

Guidelines for Rational Cancer Therapeutics

Traditionally, cancer therapy has relied on surgery, radiation therapy, and chemotherapy. In recent years, these interventions have become increasingly replaced or complemented by more targeted approaches that are informed by a deeper understanding of the underlying biology. Still, the implementation of fully rational patient-specific drug design appears to be years away. Here, we present a vision of rational drug design for cancer that is defined by two major components: modularity and image guidance. We suggest that modularity can be achieved by combining a nanocarrier and an oligonucleotide component into the therapeutic. Image guidance can be incorporated into the nanocarrier component by labeling with a specific imaging reporter, such as a radionuclide or contrast agent for magnetic resonance imaging. While limited by the need for additional technological advancement in the areas of cancer biology, nanotechnology, and imaging, this vision for the future of cancer therapy can be used as a guide to future research endeavors.

Redox-Sensitive Cerium Oxide Nanoparticles Protect Human Keratinocytes from Oxidative Stress Induced by Glutathione Depletion

Cerium oxide nanoparticles (CeNPs) have gathered much attention in the biomedical field due to its unique antioxidant property. It can protect cells and tissues from oxidative stress induced damage due to its autoregenerative redox cycle. Our study explores the antioxidant and antigenotoxic behavior of PEGylated CeNPs toward oxidative insult produced by buthionine sulfoximine (BSO) in human keratinocytes (HaCaT cells). BSO inhibits the γ-glutamylcysteinesynthetase (γ-GCS) enzyme and thus acts as a glutathione (GSH) depleting agent to modulate the cellular redox potential. GSH is a natural ROS scavenger present in the mammalian cells, and its depletion causes generation of reactive oxygen species (ROS). In this study, we challenged HaCaT cells (keratinocytes) with BSO to alter the redox potential within the cell and monitored toxicity, ROS generation, and nuclear fragmentation. We also followed changes in expressions of related proteins and genes. We found that PEGylated CeNPs can protect HaCaT cells from BSO-induced oxidative damage. BSO-exposed cells, preincubated with PEGylated CeNPs, showed better cell survival and significant decrease in the intracellular levels of ROS. We also observed decrease in lactate dehydrogenase (LDH) release and nuclear fragmentation in CeNP-treated cells that were challenged with BSO as compared to treatment with BSO alone. Exposure of HaCaT cells with BSO leads to altered expression of antioxidant genes and proteins, i.e., thioredoxin reductase (TrxR) and peroxiredoxin 6 (Prx6) whereas, in our study, pretreatment of PEGylated CeNPs reduces the need for induction of genes that produce enzymes involved in the defense against oxidative stress. Since, growing evidence argued the involvement of ROS in mediating death of mammalian cells in several ailments, our finding reinforces the use of PEGylated CeNPs as a potent pharmacological agent under the lower cellular GSH/GSSG ratios for the treatment of diseases mediated by free radicals.

Liver-targeting liposome drug delivery system and its research progress in liver diseases

Liposome-based targeted therapy is mainly divided into active targeting, passive targeting, and physical and chemical targeting. In terms of liver targeting, because of specificity, active liver-targeting liposomes have received more and more attention, and these types of liposomes can be used in liver fibrosis, hepatitis and other chronic liver diseases. In addition, the particle size could control the passive liver targeting of liposomes, while the liver-targeted liposomes of the physical and chemical targeting type have advantages in treating hepatic carcinoma. In this paper, we focus on the basics and application of liver-targeting liposome drug delivery system in hepatic diseases.

In vivo assessment of bone marrow toxicity by gold nanoparticle-based bioconjugates in Crl:CD1(ICR) mice

Introduction

The present study aimed at evaluating the biodistribution of Tween^® 20-gold nanoparticle (GNP) conjugates and their potential toxicity on the bone marrow before moving on to Phase I clinical trials.

Materials and methods

Tween^® 20-conjugated GNPs were injected intravenously for 21 days in male Crl:CD1(ICR) mice. Body weight of the mice was evaluated each day. After the sub-chronic Tween^® 20-GNPs administration, blood samples were harvested, and a full blood count was done individually. Total Au quantity from all major organs was assessed using inductively coupled plasma mass spectrometry. One femur and the sternum obtained from each animal were used for histological assessment.

Results

Our data showed that the Tween^® 20-GNP conjugates were found in large quantities in the bladder. Au was shown to accumulate in the hematopoietic bone tissue, with significant side effects such as leucopoiesis and megakaryopoiesis. The mice had a higher white blood cell and platelet count as opposed to the control group. This suggested that the previously described leukopenic effects of isoflurane were overridden by the leucopoietic effects of Tween^® 20-GNPs.

Conclusion

It was uncertain whether the mice were reactive to Au as it is a foreign substance to the tissues or whether the side effects observed were a precursor condition of a more severe hematological condition. Au was found to be hepatotoxic, urging the need for further studies in order to achieve better in vivo compliance and exploit the immense potential of GNPs in cancer pharmacology.

Effect of gold nanoparticle size and surface coating on human red blood cells

This paper reports the impact of bovine serum albumin (BSA) coating on gold (Au) nanoparticles (NPs) with sizes of 15, 30, 50 and 70 nm on cellular uptake and haemolysis of human red blood cells (RBCs). BSA coating on gold NPs imparts extra stability in high-glutathione-containing medium, which is a major prerequisite for NPs being developed for delivery applications. BSA coating on gold NPs was characterised by Fourier transform infrared spectroscopy, whereas cellular uptake was estimated by ultraviolet–visible spectrophotometry and flow cytometry. The cellular uptake results show that the internalisation of bare gold NPs is size dependent; however, upon BSA conjugation, uptake becomes independent of particle size. Cytocompatibility of bare and BSA-coated gold NPs was assessed by MTT assay, a common method to evaluate the biocompatibility of nanomaterials, and found non-toxic. However, when bare gold NPs were exposed to human RBCs, the NPs exerted significant haemolysis, which suggests that bare gold NPs which are considered as non-toxic to mammalian cells, can be harmful to RBCs. Interestingly, BSA-coated gold NPs showed significantly lower haemolysis at similar concentrations, suggesting that BSA-coated gold NPs could be of great importance in biomedical applications.

Nanomedicine to Overcome Current Parkinson's Treatment Liabilities: A Systematic Review

Nanoparticles might be produced and manipulated to present a large spectrum of properties. The physicochemical features of the engineered nanomaterials confer to them different features, including the ability to cross the blood-brain barrier. The main objective of this review is to present the state-of-art research in nano manipulation concerning Parkinson's disease (PD). In the past few years, the association of drugs with nanoparticles solidly improved treatment outcomes. We systematically reviewed 28 studies, describing their potential contributions regarding the role of nanomedicine to increase the efficacy of known pharmacological strategies for PD treatment. Data from animal models resulted in the (i) improvement of pharmacological properties, (ii) more stable drug concentrations, (iii) longer half-live and (iv) attenuation of pharmacological adverse effects. As this approach is recent, with many of the described works being published less than 5 years ago, the expectancy is that this knowledge gives support to an improvement in the current clinical methods to the management of PD and other neurodegenerative diseases.

Emerging Therapeutic Potential of Nanoparticles in Pancreatic Cancer: A Systematic Review of Clinical Trials

Pancreatic cancer is an aggressive disease with a five year survival rate of less than 5%, which is associated with late presentation. In recent years, research into nanomedicine and the use of nanoparticles as therapeutic agents for cancers has increased. This article describes the latest developments in the use of nanoparticles, and evaluates the risks and benefits of nanoparticles as an emerging therapy for pancreatic cancer. The Preferred Reporting Items of Systematic Reviews and Meta-Analyses checklist was used. Studies were extracted by searching the Embase, MEDLINE, SCOPUS, Web of Science, and Cochrane Library databases from inception to 18 March 2016 with no language restrictions. Clinical trials involving the use of nanoparticles as a therapeutic or prognostic option in patients with pancreatic cancer were considered. Selected studies were evaluated using the Jadad score for randomised control trials and the Therapy CA Worksheet for intervention studies. Of the 210 articles found, 10 clinical trials including one randomised control trial and nine phase I/II clinical trials met the inclusion criteria and were analysed. These studies demonstrated that nanoparticles can be used in conjunction with chemotherapeutic agents increasing their efficacy whilst reducing their toxicity. Increased efficacy of treatment with nanoparticles may improve the clinical outcomes and quality of life in patients with pancreatic cancer, although the long-term side effects are yet to be defined. The study registration number is CRD42015020009.

Failures in Phase III: Causes and Consequences

Phase III randomized controlled trials (RCT) in oncology fail to lead to registration of new therapies more often than RCTs in other medical disciplines. Most RCTs are sponsored by the pharmaceutical industry, which reflects industry's increasing responsibility in cancer drug development. Many preclinical models are unreliable for evaluation of new anticancer agents, and stronger evidence of biologic effect should be required before a new agent enters the clinical development pathway. Whenever possible, early-phase clinical trials should include pharmacodynamic studies to demonstrate that new agents inhibit their molecular targets and demonstrate substantial antitumor activity at tolerated doses in an enriched population of patients. Here, we review recent RCTs and found that these conditions were not met for most of the targeted anticancer agents, which failed in recent RCTs. Many recent phase III RCTs were initiated without sufficient evidence of activity from early-phase clinical trials. Because patients treated within such trials can be harmed, they should not be undertaken. The bar should also be raised when making decisions to proceed from phase II to III and from phase III to marketing approval. Many approved agents showed only better progression-free survival than standard treatment in phase III trials and were not shown to improve survival or its quality. Introduction of value-based pricing of new anticancer agents would dissuade the continued development of agents with borderline activity in early-phase clinical trials. When collaborating with industry, oncologists should be more critical and better advocates for cancer patients.

Zwitterionic-Modified Starch-Based Stealth Micelles for Prolonging Circulation Time and Reducing Macrophage Response

Over the last few decades, nanoparticles have been emerging as useful means to improve the therapeutic efficacy of drug delivery and medical diagnoses. However, the heterogeneity and complexity of blood as a medium is a fundamental problem; large amounts of protein can be adsorbed onto the surface of nanoparticles and cause their rapid clearance before reaching their target sites, resulting in the failure of drug delivery. To overcome this challenge, we present a rationally designed starch derivative (SB-ST-OC) with both a superhydrophilic moiety of zwitterionic sulfobetaine (SB) and a hydrophobic segment of octane (OC) as functional groups, which can self-assemble into "stealth" micelles (SSO micelles). The superhydrophilic SB kept the micelles stable against aggregation in complex media and imbued them with "stealth" properties, eventually extending their circulation time in blood. In stability and hemolysis tests the SSO micelles showed excellent protein resistance properties and hemocompatibility. Moreover, a phagocytosis test and cytokine secretion assay confirmed that the SSO micelles had less potential to trigger the activation of macrophages and were more suitable as a drug delivery candidate in vivo. On the basis of these results, doxorubicin (DOX), a hydrophobic drug, was used to investigate the potential application of this novel starch derivative in vivo. The results of the pharmacokinetic study showed that the values of the plasma area under the concentration curve (AUC) and elimination half-life (T1/2) of the SSO micelles were higher than those of micelles without SB modifications. In conclusion, the combination of excellent protein resistance, lower macrophage activation, and longer circulation time in vivo makes this synthesized novel starch derivative a promising candidate as a hydrophobic drug carrier for long-term circulation in vivo.

Metal-based quantum dots: synthesis, surface modification, transport and fate in aquatic environments and toxicity to microorganisms

The intense interest in metal-based QDs is diluted by the fact that they cause risks to aquatic environments.

Multisensitive drug-loaded polyurethane/polyurea nanocapsules with pH-synchronized shell cationization and redox-triggered release

A one-pot versatile method for the preparation of sub-30 nm multisensitive polyurethane/polyurea nanocapsules with pH-synchronized shell cationization is presented. The nanocapsules have been loaded with different drugs which are released through a redox-triggered mechanism.

Docetaxel-conjugated monomethoxy-poly(ethylene glycol)-b-poly(lactide) (mPEG-PLA) polymeric micelles to enhance the therapeutic efficacy in oral squamous cell carcinoma

In this study, docetaxel (DTX) was successfully conjugated to the monomethoxy-poly(ethylene glycol)-b-poly(lactide) (mPEG-PLA) polymer block via an ester linkage (DTX-PM).

Interactions between nanosized materials and the brain

The current rapid development of nanotechnologies and engineered nanomaterials (ENM) will impact the society in a major fashion during the coming decades. This development also causes substantial safety concerns. Among the many promising applications of ENM, products that can be used for diagnosis and treatment of diseases, including conditions that affect the nervous system, are under development. ENM can pass the blood brain barrier (BBB) and accumulate within the brain. It seems that the nano-form rather than the bulk form of the chemicals pass the BBB, and that there is an inverse relationship between particle size and the ability to penetrate the BBB. Although translocation of ENM to the brain is possible during experimental conditions, the health relevance for real-life situations is far from clear. One major reason for this is that studies have been using nanoparticle concentrations that are far higher than the ones that can be expected during realistic exposures. However, very high exposure to the CNS can cause effects on neurotransmission, redox homeostasis and behavior. Available studies have been focusing on possible effects of the first generation of ENM. It will be necessary to study possible health effects also of expected novel sophisticated materials, independent of the outcome of present studies. The prospects for intended or targeted medical applications are promising since it has been shown that ENM can be made to pass the BBB and reach specific regions or cells within the brain.

pHe-induced charge-reversible NIR fluorescence nanoprobe for tumor-specific imaging

Inspired by the specificity of acid tumor microenvironment, we constructed a flexible charge-reversible near-infrared (NIR) fluorescence nanoprobe in response to tumor extracellular pH (pHe) for effective tumor-specific imaging. The nanoprobe consists of an NIR-emitted CuInS2/ZnS quantum dot (CIS/ZS QDs) core and a tailored lauric acid and 2,3-dimethylmaleic anhydride modified ε-polylysine (ε-PL-g-LA/DMA) shell, which provides not only a dense protective layer for the QDs but also the ability of pHe-induced positive charge-mediated endocytosis into tumor cells. The results showed that the QDs@ε-PL-g-LA/DMA nanoprobe with a uniform size of 40 nm had high chemical stability at pH 7.4 and excellent optical properties. Especially, it swiftly reversed its surface charge to positive in 20 min when exposed to pHe due to the cleavage of the β-carboxyl amide bond of ε-PL-g-LA/DMA. Moreover, the cell uptake of the pHe-sensitive QDs nanoprobe exposed at pH 6.8 into HeLa cells is much more significant than that at pH 7.4, which further verified the availability of the electrostatic adsorptive endocytosis facilitated targeting ability. The pHe-induced targeting imparted the QDs nanoprobe a broad targeting ability in a variety of solid tumors. Furthermore, as an effective alternative mechanism for tumor targeting, responsive charge reversion is also universally applicable to other cancer theranostics agent.

Short-term changes in intracellular ROS localisation after the silver nanoparticles exposure depending on particle size

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Exposing cells to nanosilver particles (AgNPs) immediately induces ROS.

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Smaller AgNPs induce mitochondrial ROS production.

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AgNP-induced mitochondrial ROS are independent of particle internalisation.

Silver nanoparticles (AgNPs) induce the production of reactive oxygen species (ROS) and apoptosis. These effects are enhanced by smaller particles. Using live-cell imaging, we show that AgNPs induced ROS production rapidly in a size-dependent manner after exposure of cells to 70-nm and 1-nm AgNPs (AgNPs-70, AgNPs-1), but not AgNO₃. Exposure of cells to 5 μg/mL each of AgNPs-70, AgNPs-1 or AgNO₃ for 1 h decreased the cell viability by approximately 40%, 100% and 20%, respectively. ROS were rapidly induced after 5 and 60 min by AgNPs-1 and AgNPs-70, respectively, whereas AgNO₃ had no detectable effect. ROS production detected using the reporter dichlorodihydrofluorescein was observed in whole cells and mitochondria 5 and 60 min after exposure to AgNPs-1. The present study is the first, to our knowledge, to report the temporal expression and intracellular localisation of ROS induced by AgNPs.

Surface functionalization of quantum dots for biological applications

Quantum dots are a group of inorganic nanomaterials exhibiting exceptional optical and electronic properties which impart distinct advantages over traditional fluorescent organic dyes in terms of tunable broad excitation and narrow emission spectra, signal brightness, high quantum yield and photo-stability. Aqueous solubility and surface functionalization are the most common problems for QDs employed in biological research. This review addresses the recent research progress made to improve aqueous solubility, functionalization of biomolecules to QD surface and the poorly understood chemistry involved in the steps of bio-functionalization of such nanoparticles.

Sequence-defined oligoaminoamides for the delivery of siRNAs

Since it was found that synthetic small interfering RNA (siRNA) can invoke RNA interference (RNAi) responses in mammalian cells, it has gained enormous attention as a tool for gene silencing in basic science and as a novel therapeutic modality. To develop carriers for cytosolic and systemic siRNA delivery, our laboratory has recently developed a sequence-defined polymer platform compatible with solid-phase-supported synthesis. These polymers have displayed efficient siRNA-mediated gene silencing in vitro and in vivo. In this chapter, we provide a brief background on the special features of these polymers and detailed protocols to evaluate polyplex formation, gene silencing efficiency, and cytotoxicity of siRNA-containing polyplexes.

Selective inhibition of liver cancer growth realized by the intrinsic toxicity of a quantum dot-lipid complex

Using the intrinsic toxicity of nanomaterials for anticancer therapy is an emerging concept. In this work, we discovered that CdTe/CdS quantum dots, when coated with lipids (QD-LC) instead of popular liposomes, polymers, or dendrimers, demonstrated extraordinarily high specificity for cancer cells, which was due to the difference in the macropinocytosis uptake pathways of QD-LC between the cancer cells and the normal cells. QD-LC-induced HepG2 cell apoptosis was concomitant with the activation of the JNK/caspase-3 signaling pathway. Moreover, QD-LC treatment resulted in a delay in the latent period for microtumor formation of mouse hepatocarcinoma H22 cells and inhibited tumor growth, with a reduction of 53.2% in tumor volume without toxicity in major organs after intratumoral administrations to tumor-bearing mice. Our results demonstrate that QD-LC could be a very promising theranostic agent against liver cancer.

Closing the gap: accelerating the translational process in nanomedicine by proposing standardized characterization techniques

On the cusp of widespread permeation of nanomedicine, academia, industry, and government have invested substantial financial resources in developing new ways to better treat diseases. Materials have unique physical and chemical properties at the nanoscale compared with their bulk or small-molecule analogs. These unique properties have been greatly advantageous in providing innovative solutions for medical treatments at the bench level. However, nanomedicine research has not yet fully permeated the clinical setting because of several limitations. Among these limitations are the lack of universal standards for characterizing nanomaterials and the limited knowledge that we possess regarding the interactions between nanomaterials and biological entities such as proteins. In this review, we report on recent developments in the characterization of nanomaterials as well as the newest information about the interactions between nanomaterials and proteins in the human body. We propose a standard set of techniques for universal characterization of nanomaterials. We also address relevant regulatory issues involved in the translational process for the development of drug molecules and drug delivery systems. Adherence and refinement of a universal standard in nanomaterial characterization as well as the acquisition of a deeper understanding of nanomaterials and proteins will likely accelerate the use of nanomedicine in common practice to a great extent.