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Significance We constructed simple cells (SimCells) whose native chromosomes were removed and replaced by synthetic genetic circuits. The chromosome-free SimCells can process designed DNA and express target genes for an extended period of time. The strategy of SimCell generation is applicable to most bacteria, creating a universal platform for reprogramming bacteria. We demonstrated that SimCells can be designed as safe agents for bacterial therapy through synthesis and delivery of a potent anticancer drug against a variety of cancer cell lines. This showed that the nonreplicating and programmable property of SimCells is advantageous for applications in sensitive environments. The results of this work will both improve our understanding of natural living systems and simultaneously lay the foundations for future advances in synthetic biology., A type of chromosome-free cell called SimCells (simple cells) has been generated from Escherichia coli, Pseudomonas putida, and Ralstonia eutropha. The removal of the native chromosomes of these bacteria was achieved by double-stranded breaks made by heterologous I-CeuI endonuclease and the degradation activity of endogenous nucleases. We have shown that the cellular machinery remained functional in these chromosome-free SimCells and was able to process various genetic circuits. This includes the glycolysis pathway (composed of 10 genes) and inducible genetic circuits. It was found that the glycolysis pathway significantly extended longevity of SimCells due to its ability to regenerate ATP and NADH/NADPH. The SimCells were able to continuously express synthetic genetic circuits for 10 d after chromosome removal. As a proof of principle, we demonstrated that SimCells can be used as a safe agent (as they cannot replicate) for bacterial therapy. SimCells were used to synthesize catechol (a potent anticancer drug) from salicylic acid to inhibit lung, brain, and soft-tissue cancer cells. SimCells represent a simplified synthetic biology chassis that can be programmed to manufacture and deliver products safely without interference from the host genome.

The aim of this Special Issue, “Nanoparticles for cancer therapy”, was to offer readers a comprehensive and up-to-date insight into the various applications of nanoparticles in cancer treatments [...]

Nanomedicines have received considerable interest for the past few decades, and consequently, millions of funding for research have been allotted in this field. However, its industrial transformation still remains limited. The limitation is mostly due to various pharmacological effects produced by the interactions of nanomedicine with biological entities. Major dropout of the nanomedicine resulted at preclinical or clinical states due to unwanted, undesired interaction of nanomedicine with intended target site or interacting with altogether different targets. The interaction of nanomedicines with undesired targets results in a serious decrease in efficiency (when compared to laboratory values in the absence of biological barriers). Although laboratory developed surface functionalized biocompatible nanomedicine has shown some promise in the diagnosis and imaging of cancer, it has the disadvantage of rapid clearance by the immune system.

Recent clinical cohort studies have highlighted that there is a three-fold greater SARS-Cov-2 infection risk in cancer patients, and overall mortality in individuals with tumours is increased by 41% with respect to general COVID-19 patients. Thus, access to therapeutics and intensive care is compromised for people with both diseases (comorbidity) and there is risk of delayed access to diagnosis. This comorbidity has resulted in extensive burden on the treatment of patients and health care system across the globe; moreover, mortality of hospitalized patients with comorbidity is reported to be 30% higher than for individuals affected by either disease. In this data-driven review, we aim specifically to address drug discoveries and clinical data of cancer management during the COVID-19 pandemic. The review will extensively address the treatment of COVID-19/cancer comorbidity; treatment protocols and new drug discoveries, including the description of drugs currently available in clinical settings; demographic features; and COVID-19 outcomes in cancer patients worldwide.

‘Bioinks’ are important tools for the fabrication of artificial living-tissue constructs that are able to mimic all properties of native tissues via 3D bioprinting technologies. Bioinks are most commonly made by incorporating live cells of interest within a natural or synthetic biocompatible polymeric matrix. In oncology research, the ability to recreate atumor microenvironment(TME) using by 3D bioprinting constitutes a promising approach for drug development, screening, andin vitrocancer modeling. Here, we review the different types of bioink used for 3D bioprinting, with a focus on its application in cancer management. In addition, we consider the fabrication of bioink using customized materials/cells and their properties in the field of cancer drug discovery.

Nanomaterials have outstanding applications in biomedical areas, such as drug delivery agents, nanoparticles-based imaging, magnetic fluid hyperthermia, and tissue regeneration. In the line of extensive development in nanomaterials-aided drug delivery platforms, pharmacokinetic assessments have achieved greater consideration from scientists and pharmacists as a fundamental component of the study of these nanosystems. Pharmacokinetics is nothing but the study of liberation, absorption, distribution, metabolization, and excretion (i.e., LADME) of the particular drug at the molecule scale, which provides significant information about drug response and associated side effects. The utilization of nano platforms in the delivery of drugs explores new possibilities to deliver drugs in the form of particulates, which specifically alters the LADME profile. The proper information of the pharmacokinetics aspects associated with the LADME plays a vital role in designing appropriate nanomaterials-based drug delivery systems for final clinical assessments. The pharmacokinetics of the nanomaterials is primarily dependent on the adsorption of proteins, which is consecutively decided by the physicochemical properties of the nanomaterials. Thus, more insights into the interrelation between the physicochemical properties of nanomaterials and their interface with body is required to recognize and envisage thein vivoresponse of the nanomaterials. In this chapter, we highlight some of the recent insights of the pharmacokinetic investigations of nanomaterials. We also provide the correlation between the physicochemical properties of the nanoscale materials and their biological behavior.

Human exposure to engineered nanomaterials (ENMs) is growing rapidly but their effects on human health are still largely unknown. In the last decade, we have witnessed a tremendous increase in the use of nanoparticles and nanomaterials in several areas of human life such as food, cosmetic, medicine, and agriculture. However, this rise in use increases the laboratory synthesis and industrial production of ENMs and is the cause of potential exposure of humans to ENMs. It is expected that human exposure to ENMs will continue to increase in the near future. So, the potential human health effects need to be evaluated. Therefore there is a need for better tools to evaluate the safety of ENMs. The purpose of this chapter is to present the current scenarios regarding the potential routes of human exposure to ENMs and their subsequent health effects. The chapter mainly focuses on the different release mechanisms of ENMs in human environment, their possible routes of exposure and health effects associated with their exposure to humans.

Ophiobolin A is a secondary phytotoxic metabolite produced by some pathogenic fungal species responsible for severe plant diseases, considered to play a role in disease development and symptom appearance. Herein we investigated whether the phytotoxic activities of ophiobolin A against weed species could be improved by nanoencapsulation. Given the rapid natural degradation of the compound, it was hoped that nanoencapsulation would prolong the phytotoxic effects or enhance the bioactivity, thus leading to improved weed control capabilities. This article presents an assessment of the effectiveness of encapsulated ophiobolin A on 11 commonly found weed species, compared to the pure ophiobolin, to the particle alone, and a combination of mixed particles and ophiobolin A, by applying the solution droplets to both intact or injured leaf surface, on the adaxial or abaxial side. The bioassays showed the improved efficacy of the encapsulated ophiobolin, and the need for leaf lesions to diffuse the particles into the tissues.[Formula: see text].

Rhabdomyosarcoma (RMS) is a rare type of soft tissue sarcoma most commonly found in pediatric patients. Despite progress, new and improved drug regimens are needed to increase survival rates. Citral, a natural product plant oil can induce cell death in cancer cells. Another compound, metformin, isolated originally from French lilac and used by diabetics, has been shown to reduce the incidence of cancer in these patients. Application of citral to RMS cells showed increase in cell death, and RD and RH30 cells showed half maximal inhibitory concentration (IC50) values as low as 36.28 μM and 62.37 μM, respectively. It was also shown that the citral initiated cell apoptosis through an increase in reactive oxygen species (ROS) and free calcium. In comparison, metformin only showed moderate cell death in RMS cell lines at a very high concentration (1,000 μM). Combinatorial experiments, however, indicated that citral and metformin worked antagonistically when used together. In particular, the ability of metformin to quench the ROS induced by citral could lead to the suppression of activity. These results clearly indicate that while clinical use of citral is a promising anti-tumor therapy, caution should be exercised in patients using metformin for diabetes.

Plant volatile organic compounds (volatiles) are secondary plant metabolites that play crucial roles in the reproduction, defence, and interactions with other vegetation. They have been shown to exhibit a broad range of biological properties and have been investigated for antimicrobial and anticancer activities. In addition, they are thought be more environmentally friendly than many other synthetic chemicals 1. Despite these facts, their applications in the medical, food, and agricultural fields are considerably restricted due to their volatilities, instabilities, and aqueous insolubilities. Nanoparticle encapsulation of plant volatile organic compounds is regarded as one of the best strategies that could lead to the enhancement of the bioavailability and biological activity of the volatile compounds by overcoming their physical limitations and promoting their controlled release and cellular absorption. In this review, we will discuss the biosynthesis and analysis of plant volatile organic compounds, their biological activities, and limitations. Furthermore, different types of nanoparticle platforms used to encapsulate the volatiles and the biological efficacies of nanoencapsulated volatile organic compounds will be covered.

Cancer cell resistance to chemotherapeutics (chemoresistance) poses a significant clinical challenge that oncology research seeks to understand and overcome. Multiple anticancer drugs and targeting agents can be incorporated in nanomedicines, in addition to different treatment modalities, forming a single nanoplatform that can be used to address tumor chemoresistance. Nanomedicine-driven molecular assemblies using nucleic acids, small interfering (si)RNAs, miRNAs, and aptamers in combination with stimuli-responsive therapy improve the pharmacokinetic (PK) profile of the drugs and enhance their accumulation in tumors and, thus, therapeutic outcomes. In this review, we highlight nanomedicine-driven molecular targeting and therapy combination used to improve the 3Rs (right place, right time, and right dose) for chemoresistant tumor therapies.

Biogenic silver nanoparticles are used for a number of applications due to their size, surface characteristics and strong antimicrobial properties. The present study aimed to investigate the synthesis of silver nanoparticles from the indigenous bacterial strain Bacillus sp. MB353 (PRJNA357966). Detailed characterization of silver nanoparticles was performed by UV–vis Spectrophotometer, FTIR, SEM and XRD. Biogenic silver nanoparticles were crystalline with average size 49−53 nm. These silver nanoparticles demonstrated good antibacterial activity against Gram-positive and Gram-negative bacteria (E. coli, Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumoniae, Enterococcus faecium, Enterococcus faecalis and Streptomyces laurentii). The nanoparticles also showed excellent antifungal activity against Aspergillus niger, Aspergillus fumigatus, Fusarium soleni. The silver nanoparticles showed negligible antioxidant activity, but ROS generation pointed to a possible mode of antimicrobial activity. Incubation of silver nanoparticles with mammalian cell lines (Rhabdomyosarcomas and fibroblast) showed cell death and inhibition of proliferation. Cytotoxicity was most likely a result of ROS generation and changes in intracellular calcium levels. These findings suggested that biogenic silver nanoparticles could be used as alternative agents for biomedical purposes such as antibacterial and antifungal agents. However, given the effects on normal mammalian cells, it is probable that they could be used as anticancer agents if applied in targeted therapies.

To date, various chemically synthesized and biosynthesized nanoparticles, or hybrid nanosystems and/or nanoplatforms, have been developed under the umbrella of nanomedicine. These can be introduced into the body orally, nasally, intratumorally or intravenously. Successfully translating hybrid nanoplatforms from preclinical proof-of-concept to therapeutic value in the clinic is challenging. Having made significant advances with drug delivery technologies, we must learn from other areas of oncology drug development, where patient stratification and target-driven design have improved patient outcomes. This review aims to identify gaps in our understanding of the current strengths of nanomedicine platforms in drug delivery and cancer theranostics. We report on the current approaches of nanomedicine at preclinical and clinical stages.

Glioblastoma is a heterogeneous disease with multiple genotypic origins. Despite treatment protocols such as surgery, radiotherapy and chemotherapy, the prognosis for patients remains poor. This study investigates the cytotoxic and radiation dose-enhancing and radiosensitizing ability of five rare earth oxide nanoparticles, in two different immortalized mammalian cell lines; U-87 MG and Mo59K. Significant cytotoxicity was observed in U-87 MG cells when exposed to Nd

Essential oils are volatile plant compounds that are biologically active and play an important role in natural plant protection. There are currently ∼3000 essential oils known, of which over 300 are commercially important for a variety of industries. In fact, the essential oil global market has been estimated to reach 13.94 billion USD with a demand of over 370,000 tons by 2024. These compounds have a wide variety of applications in agriculture, food and beverage, cosmetics, medicine, amongst other industries. A promising application of essential oils is as antimicrobials to target the vast number of diseases affecting crops. However, their volatile nature limits their effective use as free agents. To overcome this, we have investigated the use of mesoporous silica nanoparticles to protect essential oils from evaporation and degradation and to enhance their antimicrobial activity against bacterial phytopathogens. Silica nanoparticles were used due to their potential to be produced at an industrial scale and their biocompatibility. As a proof of concept, we evaluated 41 essential oils against bacterial phytopathogen Pseudomonas syringae pv. pisi, causative agent of pea bacterial blight. Additionally, we compared the effect of such essential oils against Pectobacterium carotovorum subsp. carotovorum and Pseudomonas fluorescens. Two of the most effective antimicrobials, cinnamon (Cinnamomum zeylanicum) and mustard (Brassica nigra) oils, were able to inhibit bacterial growth after 24 h at a concentration as low as 0.016% (v/v). Besides efficacy, the species-specificity of essential oils was demonstrated with >67% of oils tested displaying specificity towards pathogenic P. syringae pv. pisi over non-pathogenic Pseudomonas fluorescens. Furthermore, the encapsulation of essential oils into mesoporous silica nanoparticles (MSNPs) as a means of extending and improving their antimicrobial effect was found to enable a 10-fold increase in potency compared to the free essential oil. Cinnamaldehyde immobilised onto MSNPs proved to be the most effective antimicrobial, eliminating >99.8%, >99.9%, and >95% bacterial growth of P. fluorescens, P. syringae pv. pisi and P. carotovorum subsp. carotovorum, respectively. This system has the potential to be used to treat and prevent bacterial infections in crops and to enable a more controlled and effective exploitation of volatile compounds as antimicrobials.

Rachel A Morrison,1,* Malgorzata J Rybak-Smith,1,* James M Thompson,2 Bénédicte Thiebaut,3 Mark A Hill,2 Helen E Townley1,4 1Department of Engineering Science, 2Gray Laboratories, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, 3Johnson Matthey, Technology Centre, Reading, Berkshire, 4Nuffield Department of Obstetrics and Gynaecology, John Radcliffe Hospital, University of Oxford, Oxford, UK *These authors have contributed equally to this work Abstract: The aim of this study was to develop a manufacturing protocol for large-scale production of doped titania radiosensitizing nanoparticles (NPs) to establish their activity under hypoxia and to produce a multimodal radiosensitizing embolic particle for cancer treatment. We have previously shown that radiosensitizing NPs can be synthesized from titania doped with rare earth elements, especially gadolinium. To translate this technology to the clinic, a crucial step is to find a suitable, scalable, high-throughput method. Herein, we have described the use of flame spray pyrolysis (FSP) to generate NPs from titanium and gadolinium precursors to produce titania NPs doped with 5at% gadolinium. The NPs were fully characterized, and their capacity to act as radiosensitizers was confirmed by clonogenic assays. The integrity of the NPs in vitro was also ascertained due to the potentially adverse effects of free gadolinium in the body. The activity of the NPs was then studied under hypoxia since this is often a barrier to effective radiotherapy. In vitro radiosensitization experiments were performed with both the hypoxia mimetics deferoxamine and cobalt chloride and also under true hypoxia (oxygen concentration of 0.2%). It was shown that the radiosensitizing NPs were able to cause a significant increase in cell death even after irradiation under hypoxic conditions such as those found in tumors. Subsequently, the synthesized NPs were used to modify polystyrene embolization microparticles. The NPs were sintered to the surface of the microparticles by heating at 230°C for 15minutes. This resulted in a good coverage of the surface and to generate embolization particles that were shown to be radiosensitizing. Such multimodal particles could therefore result in occlusion of the tumor blood vessels in conjunction with localized reactive oxygen species generation, even under hypoxic conditions such as those found in the center of tumors. Keywords: cancer, ROS, reactive oxygen species, titania, multimodal

Nanoparticles may be used in vaccinology as an antigen delivery and/or an immunostimulant to enhance immunity. Porous silica has been identified as an effective adjuvant for more than a decade, and we have therefore investigated the take up rate by an immortalized macrophage-like cell line of a number of mesoporous silica nanoparticles (MSNPs) with differing diameter and pore size. The MSNPs were synthesized using a sol-gel reaction and post-synthesis removal of the template. The MSNPs showed a clear distribution in take up rate peaking at 217 nm, whereas a comparison with solid spherical nanoparticles showed a similar distribution peaking at 377 nm. The MSNPs were investigated before and after loading with antigen. Diphtheria toxoid was used as a proof-of-concept antigen and showed a peak macrophage internalization of 53.42% for loaded LP3 particles which had a diameter of 217.75 ± 5.44 nm and large 16.5 nm pores. Optimal MSNP sizes appeared to be in the 200–400 nm range, and larger pores showed better antigen loading. The mesoporous silica particles were shown to be generally biocompatible, and cell viability was not altered by the loading of particles with or without antigen.

In this review, we intend to highlight the progress which has been made in recent years around different types of smart activation nanosystems for cancer treatment. Conventional treatment methods, such as chemotherapy or radiotherapy, suffer from a lack of specific targeting and consequent off-target effects. This has led to the development of smart nanosystems which can effect specific regional and temporal activation. In this review, we will discuss the different methodologies which have been designed to permit activation at the tumour site. These can be divided into mechanisms which take advantage of the differences between healthy cells and cancer cells to trigger activation, and those which activate by a mechanism extrinsic to the cell or tumour environment.

Dysregulation of iron metabolism is a common characteristic of cancer cells. The rapid proliferation of the tumour cells means that there is an increased dependence upon iron compared to healthy cells. Chelation of iron can be undertaken with a number of different compounds, however, simply lowering systemic iron levels to control tumour growth is not possible since iron is essential for cellular metabolism in the rest of the body. Nanoparticulate iron chelators could overcome this difficulty by targeting to the tumour either by the passive enhanced permeation and retention effect, or by targeting ligands on the surface. Nanoparticles were prepared from melanin, which is a naturally occurring pigment that is widely distributed within the body, but that can chelate iron. The prepared nanoparticles were shown to be ~220 nm, and could adsorb 16.45 mmoles iron/g melanin. The nanoparticles showed no affect on control fibroblast cells at a concentration of 200 μM, whereas the immortalised cancer cell lines showed at least 56% reduction in cell growth. At a concentration of 1 mM melanin nanoparticles the cell growth could be reduced by 99% compared to the control. The nanoparticles also show no significant haemotoxicity, even at concentration of 500 μM. Melanin nanoparticles are therefore a viable prospect for destroying cancer cells via iron starvation.

Drug delivery using synthetic mesoporous nanomaterials, including porous silicon, has been extensively used to ameliorate the constraints currently experienced with conventional chemotherapy. Owing to the amazing potential, the silica based nanomaterials have been used widely. Nevertheless, synthetic nanomaterial involves high cost, lack of scalability, and the use of toxic substances limits its utilization. These issues can be overcome by the use of nature generated nanoscale materials, such as diatoms would serve as a boon for pharmaceutical industries. In this study we investigate the use of a mesoporous, biodegradable nanomaterial obtained from the natural silica found in the diatom species Amphora subtropica (AMPS) for drug delivery applications. AMPS cultures cleaned and chemically treated to obtain Amphora frustules (exoskeleton) (AF), followed by surface functionalization with chitosan (Chi). Results of our experiments demonstrate high drug loading, strong luminescence, biodegradable and biocompatible nature of the doxorubicin tethered diatom. Further, toxicity studies employing immortalized lung cancer cell line (A549) indicates sustained drug delivery and less toxic compared to the free doxorubicin (DOX), suggesting AF could be an excellent substitute for synthetic nanomaterials used in drug delivery applications.

Natural biocides, such as cinnamon (Cinnamomum zeylanicum) bark essential oil, have enormous potential as antimicrobials but are limited by their volatility and rapid degradation. To counteract this and to prolong the efficacy of the biocide, cinnamaldehyde (CNAD, the main bioactive compound of cinnamon essential oil) was encapsulated into mesoporous silica nanoparticles (MSNPs). The synthesised CNAD-MSNPs can be used to tackle the issue of global crop loss; every year, more than 40% of global food production (estimated at $500 billion USD) is lost to diseases. This is despite the annual use of over two million tonnes of pesticides. To address seed borne diseases, CNAD-MSNPs were incorporated into a sodium alginate seed coating. As a proof of concept, this system was tested against Pseudomonas syringae pv. pisi, the causative agent of pea bacterial blight, and demonstrated to increase the number of symptomless plants by 143.58% twenty days after sowing. Additionally, the concentration of CNAD present in the alginate coating was estimated to be

This study describes a system for quantifying paclitaxel activity using the C-terminus of α-tubulin as a biomarker. Following stabilization of microtubules with paclitaxel, a specific detyrosination reaction occurs at the C-terminus of α-tubulin which could be used to assess efficacy. A fluorescence resonance energy transfer (FRET) based biosensor was synthesized comprising a short peptide that corresponded to the C-terminus of α-tubulin, a fluorophore (Abz), and a quencher (Dnp). The fluorophore added to the end of the peptide can be released upon enzymatic detyrosination. In addition, a single fluorophore-tagged peptide was also conjugated to mesoporous silica nanoparticles to examine the feasibility of combining the drug with the peptide biomarker. As a proof of concept, we found that the degree of peptide cleavage, and therefore enzymatic activity, was directly correlated with exogenous bovine carboxypeptidase (CPA) an enzyme that mimics endogenous detyrosination. In addition, we show that cell lysates obtained from paclitaxel-treated cancer cells competed with exogenous CPA for biosensor cleavage in a paclitaxel dose-dependent manner. Our work provides strong evidence for the feasibility of combining paclitaxel with a novel biosensor in a multi-load nanoparticle.

Benjamin White,1 Anna Evison,1 Eszter Dombi,1 Helen E Townley1,2 1Nuffield Department of Obstetrics and Gynaecology, Women’s Centre, John Radcliffe Hospital, 2Department of Engineering Science, Oxford University, Oxford, UK Abstract: Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children, with a 5-year survival rate of between 30 and 65%. Standard treatment involves surgery, radiation treatment, and chemotherapy. However, there is a high recurrence rate, particularly from locoregional spread. We investigated the use of the natural compound citral (3,7-dimethyl-2,6-octadienal), which can be found in a number of plants, but is particularly abundant in lemon grass (Cymbopogon citratus) oil, for activity against immortalized RMS cells. Significant cancer cell death was seen at concentrations above 150 μM citral, and mitochondrial morphological changes were seen after incubation with 10 μM citral. However, since citral is a highly volatile molecule, we prepared albumin particles by a desolvation method to encapsulate citral, as a means of stabilization. We then further incorporated the loaded nanoparticles into a biodegradable polyanhydride wafer to generate a slow release system. The wafers were shown to degrade by 50% over the course of 25 days and to release the active compound. We therefore propose the use of the citral-nanoparticle-polymer wafers for implantation into the tumor bed after surgical removal of a sarcoma as a means to control locoregional spread due to any remaining cancerous cells. Keywords: citral, nanoparticle, wafer, biodegradable, mitochondria, toroidal, cancer, rhabdomyosarcoma, Cymbopogon citratus

The prognosis of brain cancer glioblastoma (GBM) is poor, and despite intense research, there have been no significant improvements within the last decade. This stasis implicates the need for more novel therapeutic investigation. One such option is the use of nanoparticles (NPs), which can be beneficial due to their ability to penetrate the brain, overcome the blood–brain barrier and take advantage of the enhanced permeation and retention effect of GBM to improve specificity. Rare earth elements possess a number of interesting natural properties due to their unique electronic configuration, which may prove therapeutically advantageous in an NP formulation. The underexplored exciting potential for rare earth elements to augment the therapeutic potential of NPs in GBM treatment is discussed in this review.

During radiotherapy, the reaction of radiation energy with the aqueous environment of the cell results in the generation of redox-active products. The addition of radiosensitizers can potentially amplify the effects of radiotherapy. Here, we investigated the X-ray-induced generation of reactive oxygen species (ROS) from rare earth doped titania nanoparticles. The rare earth element(s) and the levels of doping and co-doping were assessed for their ability to generate ROS. Subsequently, cellular responses to the nanoparticles were determined. As such, an increase in cellular ROS and lipid peroxidation was seen in the presence of nanoparticles. Thus, in this study, we have shown that after irradiation, the nanoparticles generate ROS and cause an upregulation in cellular ROS due to a cascade effect.

peer-reviewed Physically or externally stimulated nanostructures often employ multimodality and show encouraging results at preclinical stage in cancer therapy. Specially designed smart nanostructures such as hybrid nanostructures are responsive to external physical stimuli such as light, magnetic field, electric, ultrasound, radio frequency, X-ray, etc. These physically responsive nanostructures have been widely explored as nonconventional innovative “nanotheranostics” in cancer therapies. Physically stimulated (particularly magnetic and light) nanotheranostics provide a unique combination of important properties to address key challenges in modern cancer therapy: (i) an active tumor targeting mechanism of therapeutic drugs driven by a physical force rather than passive antibody matching, (ii) an externally/remotely controlled drugs on-demand release mechanism, and (iii) a capability for advanced image guided tumor therapy and therapy monitoring. Although primarily addressed to the scientific community, this review offers valuable and accessible information for a wide range of readers interested in the current technological progress with direct relevance to the physics, chemistry, biomedical field, and theranostics. We herein cover magnetic and light-triggered modalities currently being developed for nonconventional cancer treatments. The physical basis of each modality is explained; so readers with a physics or, materials science background can easily grasp new developments in this field.

Nanoparticulate delivery of biocides has the potential to decrease levels of exposure to non-target organisms, and miminize long-term exposure that can promote the development of resistance. Silica nanoparticles are an ideal vehicle since they are inert, biocompatible, biodegradable, and thermally and chemically stable. Encapsulation of biocides within nanoparticulates can improve their stability and longevity and maximize the biocidal potential of hydrophobic volatile compounds. Herein, we have shown that the plant secondary metabolites allyl isothiocyanate and cinnamaldehyde demonstrated increased antimicrobial activity against Escherichia coli in planktonic form, when packaged into mesoporous silica nanoparticles. Furthermore, the biocide-loaded nanoparticles showed activity against Pseudomonas aeruginosa biofilms that have inherent resistance to antimicrobial agents. The delivery platform can also be expanded to traditional biocides and other non-conventional antimicrobial agents.

Extended Abstract The current lack of preventive and treatment measures available against bacterial diseases affecting crops is an important problem in agriculture. The use of antibiotics and copper compounds is restricted and can cause bacterial resistance and negative impacts on the environment [1, 2]. Nevertheless, other successful treatment methods have not been fully established. Promising natural compounds exist which have been proven to have strong antimicrobial properties, such as essential oils, and could be used to target bacterial phytopathogens. However, the volatile nature of these compounds limits their application and use in agriculture and a suitable delivery method is extremely desirable. The aim of this study is to evaluate the use of mesoporous silica nanoparticles (MSNPs) to encapsulate essential oils and be used as a preventive and control measure against Pseudomonas syringae pv. pisi, the causative agent of pea bacterial blight [3]. MSNPs allow for a targeted and controlled delivery of the essential oil in the presence of the bacterial pathogen. Essential oils are an environmentally-friendly and safe alternative to antibiotics and other antibacterial agents and the use of nanoparticles as a delivery vehicle allows the oils to be maintained in their active form for long periods of time until their release is needed. MSNPs can protect the loaded biocide from evaporation or degradation while improving their stability and miscibility in aqueous solutions. Additionally, silica is a safe, biodegradable and biocompatible material [4] that is naturally present in plant systems and has been shown to have mainly positive effects on plant growth and development [5, 6, 7, 8]. The present study evaluated the effect of 41 essential oils against P. syringae pv. pisi and compared it to the effect on two other bacterial strains; Pectobacterium carotovorum and Pseudomonas fluorescens. The effect was shown to be strainspecific and one of the most effective oils against P. syringae pv. pisi, ajwain oil, was selected for encapsulation into the MSNPs, which were then incorporated into an alginate seed coating to treat the seeds prior to sowing. Using a seed treatment as a biocide application method reduces the quantity of antimicrobials needed, as well as the amount of nanoparticles released to the environment, when compared to other methods such as soil or foliar applications. This decreases the risk of microbial resistance to biocides while increasing the safety and efficacy of the product. The effect of different alginate formulations on the plant’s germination, growth and development was studied to assess the influence of MSNPs and the use of this technology as a seed treatment against seed-borne pathogens. Peas coated with loaded MSNPs appeared to better resist infection and grow taller than control seeds. Further experiments will be performed to optimise the loading of the MSNPs and maximise the killing efficacy against the pathogens. Additionally, the applications of this study can be extended to both other pathogens as well as other host plants. To our knowledge, this is the first report of MSNPs loaded with a natural biocide and incorporated into an alginate seed coating to protect peas from bacterial phytopathogen Pseudomonas syringae pv pisi. The development of novel and safe biocide delivery methods is essential to optimise food production and achieve a sustainable agriculture in the future.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma that is found in children and has a poor outcome for those with metastatic disease. Two histological groups have been distinguished - embryonal (ERMS) and alveolar (ARMS) forms. The ARMS subtype has higher rates of metastasis, as well as higher levels of ELMO1, which is thought to be involved in cell migration. Therefore, the knock-down of ELMO1 by targeted siRNA could provide a mechanism to prevent the metastatic behaviour of ARMS cells. However, challenges still lie in the delivery of nucleotides to a tumour site. Herein, we have described the use of a variety of mesoporous silica nanoparticles as a delivery system for siRNA that is specific for ELMO1 and shown the effective reduction in cell invasive behaviour in these cells.

Diatoms are single-celled microalgae with rigid walls (frustules) composed of amorphous silica. The intricate 3D microstructure of diatoms results in a high surface area formed by myriad pores and channels. The combination of the silica chemistry of the frustule coupled with the high surface area makes it particularly suitable for applications such as microscale total analysis systems. Here it is demonstrated that the diatom frustule can be chemically modified for the attachment of antibodies, and that the attached antibodies retain biological activity. These modified structures have potential applications in antibody arrays and may have use in techniques such as immunoprecipitation. These silica structures are produced in diatoms using only light and minimal nutrients and, therefore, generate an exceptionally cheap and renewable material.

Aim: This study aimed to investigate the effects of actively targeting mesoporous silica nanoparticles (MSNPs) toward mammalian sperm with a cell-penetrating peptide (C105Y), with subsequent analysis of binding rates and nano-safety profiles. Materials & methods: Boar sperm were exposed in vitro to C105Y-functionalized MSNPs or free C105Y, in a series of increasing doses for up to 2 h, followed by the evaluation of sperm motility, kinematic parameters, acrosome morphology, MSNP-sperm binding and cell fluorescence levels. Results: C105Y-functionalized MSNPs preserved their biocompatibility with sperm, and exhibited an approximately fourfold increase in affinity toward gametes, compared with unmodified MSNPs, during the early stages of incubation. Conclusion: Our findings support the application of MSNPs and active targeting to sperm as valuable tools for reproductive biology.

The synthetic transcription factor LhG4 has been used in numerous mis-expression studies in plants. We show that the sequence encoding the LhG4 activation domain, derived from Saccharomyces cerevisiae GAL4, contains several cryptic polyadenylation signals in Arabidopsis. The GAL4-derived sequence was modified according to preferred Arabidopsis codon usage, generating LhG4AtO which was faithfully transcribed in Arabidopsis plants. In protoplasts, LhG4AtO achieved maximum transactivation of the pOp promoter with 10-fold less input DNA than LhG4. The same methods were used to compare 10 other LhG4 derivatives that carried alternative natural or synthetic activation domains. Lh214 and Lh314, which contain synthetic activation domains comprising trimers of a core acidic activation domain, directed threefold more GUS expression from the pOp promoter with 20-fold less input DNA than LhG4. In contrast, when expressed from the CaMV 35S promoter in transgenic plants carrying a pOp-GUS reporter, Lh214 and Lh314 yielded transformants with substantially lower GUS activities than other constructs including LhG4AtO and LhG4 which performed similarly. When incorporated into an enhancer-trapping vector, however, LhG4AtO and Lh314 yielded enhancer traps with approximately twice the frequency of LhG4, suggesting that the modified activation domains offer improved performance when expressed from weaker transcription signals. To increase the number of LhG4 patterns available for mis-expression studies, we describe a population of enhancer-trap lines obtained with LhG4AtO in a pOp-GUS background. We show that enhancer-trap lines can transactivate an unlinked pOp-green fluorescent protein (pOp-GFP) reporter in the pattern predicted by staining for GUS activity.

To facilitate glucocorticoid-inducible transgene expression from the pOp promoter in Arabidopsis the ligand-binding domain of a rat glucocorticoid receptor (GR LBD) was fused to the amino terminus of the synthetic transcription factor LhG4 to generate LhGR-N. Fusions bearing the GR LBD at other positions in LhG4 exhibited incomplete repression or inefficient induction. LhGR-N was stringently repressed in the absence of exogenous glucocorticoid but was fully activated by addition of 2 microm dexamethasone which resulted in 1000-fold increase in GUS reporter activity. Half maximal induction was achieved with 0.2 microm dexamethasone. Reporter transcripts were detectable within 2 h of dexamethasone application and peaked 4-10 h later. Neither LhGR-N nor dexamethasone affected seedling development although ethanol retarded development when used as a solvent for dexamethasone. The efficiency of the pOp target promoter was improved 10- to 20-fold by incorporating six copies of the ideal lac operator with sufficient inter-operator spacing to allow simultaneous occupancy. Introduction of the TMV Omega sequence into the 5'UTR resulted in a further 10-fold increase in dexamethasone-inducible reporter activity and an increase in the induction factor to 10(4). Although promoters containing the TMV Omega sequence exhibited slightly increased basal expression levels in the absence of dexamethasone, stringent regulation of the cytokinin biosynthetic gene ipt was achieved with all promoters. Despite the severity of the induced ipt phenotypes, transcripts for the KNOX homoeodomain transcription factors BREVIPEDICELLUS and SHOOTMERISTEMLESS were not significantly increased within 48 h of dexamethasone application to seedlings.

Previous studies have implicated calmodulin as a signaling component required for the cold induction of COR ( c old o n r egulated) genes in Arabidopsis ([Braam and Davis, 1990][1]; [Tahtiharju et al., 1997][2]). Here, we present data that show that overexpression of calmodulin in planta causes

We report significant and controlled cell death using novel x-ray-activatable titania nanoparticles (NPs) doped with lanthanides. Preferential incorporation of such materials into tumor tissue can enhance the effect of radiation therapy. Herein, the incorporation of gadolinium into the NPs is designed to optimize localized energy absorption from a conventional medical x-ray. This result is further optimized by the addition of other rare earth elements. Upon irradiation, energy is transferred to the titania crystal structure, resulting in the generation of reactive oxygen species (ROS). From the Clinical Editor The authors report significant and controlled cell death using x-ray-activated titania nanoparticles doped with lanthanides as enhancers. Upon irradiation X-ray energy is transferred to the titania crystal structure, resulting in the generation of reactive oxygen species.

Diatoms are unicellular photosynthetic eurkaryotes within the class Bacillariophyceae whose peculiarity amongst other microalgae is a siliceous cell wall (Round et al., 1990). Traditionally, diatoms have been subdivided into two major groups based upon their symmetry: the centrales have radial symmetry, whilst the pennales have bilateral symmetry. Diatoms are found in both freshwater and marine environments, as well as in soil, and on moist surfaces. Individual diatoms vary in size from 2 nm up to several mm in size, although only a few species are larger than 200 mm.

We describe here a vector system that allows dexamethasone-inducible RNAi against plant genes. The system utilizes a modified pHELLSGATE vector, under the control of the pOp6 promoter, and the synthetic transcription factor, LhGR. We demonstrate that the production of RNAi-inducing hairpin RNA from this system can be regulated by the application and removal of dexamethasone. Silencing of a target gene encoding phytoene desaturase was highly effective 24 h after application of dexamethasone. In the presence of the hormone silencing was maintained for at least 5 days while removal of the inducer resulted in significant recovery within 24 h. A transgene encoding luciferase was silenced with similar speed and efficiency following application of dexamethasone but unlike phytoene desaturase, mRNA levels did not recover within 10 days after dexamethasone was removed. Insertion of target gene sequences into this vector is mediated by Gateway recombination, facilitating its use for high-throughput applications, such as gene discovery or validation. The inducibility of RNAi from this system may be useful in helping to identify the functions of genes which when constitutively silenced give embryo lethality or pleiotropic phenotypes. A modified version of this system may also be used for tissue-specific hairpin RNA expression.

While the role of C2-ceramide in the induction of programmed cell death (PCD) in animal systems has been well documented, little is known of its role in plant cells. Here we show that C2-ceramide induces PCD inArabidopsissuspension cultures, which is preceded by the generation of a calcium transient and an increase in reactive oxygen species (ROS). Inhibition of the calcium transient prevented cell death, whereas inhibition of ROS had no effect on cell survival. These observations suggest that calcium signalling plays a role in ceramide-induced PCD but is independent of the generation of ROS.

It is widely believed that protochlorophyllide reductase is a flavoenzyme effecting catalysis by a radical mechanism. Here the cyanobacterial reductase has been isolated from Escherichia coli overexpressing the Synechocystis gene. The purified enzyme, while retaining full activity, has no detectable flavine. No radical derived ESR signal was observed during catalysis or on photoexcitation under non-catalytic conditions. Mechanistic implications of the findings are discussed.

Radiation therapy is often limited by damage to healthy tissue and associated side-effects; restricting radiation to ineffective doses. Preferential incorporation of materials into tumour tissue can enhance the effect of radiation. Titania has precedent for use in photodynamic therapy (PDT), generating reactive oxygen species (ROS) upon photoexcitation, but is limited by the penetration depth of UV light. Optimization of a nanomaterial for interaction with X-rays could be used for deep tumour treatment. As such, titania nanoparticles were doped with gadolinium to optimize the localized energy absorption from a conventional medical X-ray, and further optimized by the addition of other rare earth (RE) elements. These elements were selected due to their large X-ray photon interaction cross-section, and potential for integration into the titania crystal structure. Specific activation of the nanoparticles by X-ray can result in generation of ROS leading to cell death in a tumour-localized manner. We show here that intratumoural injection of RE doped titania nanoparticles can enhance the efficacy of radiotherapy in vivo.

In this paper we demonstrate how the photonic properties of a diatom can be altered by growth with a metal pollutant. Both the optical and physical properties of the silica frustule of the diatom Coscinodiscus wailesii were affected by the presence of nickel sulfate in sea water. It was found that a sublethal concentration of the metal both significantly modified the size of the pores of the valves and quenched the intrinsic PL of the amorphous silica. Since cytoplasmic structures may be involved in determining the frustule architecture, we also present TEMs of nickel-grown diatoms and show the affected organelles. The ability to modify the properties of the frustule shows that mechanisms exist for the alteration of existing structures in nature to optimize specific characteristics for exploitation in biotechnological applications.