Advances in the field of nanooncology

Biosynthesized metallic nanoparticles: A new era in cancer therapy

Cancer remains a global health crisis, claiming countless lives throughout the years. Traditional cancer treatments like chemotherapy and radiation often bring about severe side effects, underscoring the pressing need for innovative, more efficient, and less toxic therapies. Nanotechnology has emerged as a promising technology capable of producing environmentally friendly anticancer nanoparticles. Among various nanoparticle types, metal-based nanoparticles stand out due to their exceptional performance and ease of use in methods of imaging. The widespread accessibility of biological precursors for synthesis based on plants of metal nanoparticles has made large-scale, eco-friendly production feasible. This evaluation provides a summary of the green strategy for synthesizing metal-based nanoparticles and explores their applications. Moreover, this review delves into the potential of phyto-based metal nanoparticles in combating cancer, shedding light on their probable mechanisms of action. These insights are invaluable for enhancing both biomedical and environmental applications. The study also touches on the numerous potential applications of nanotechnology in the field of medicine. Consequently, this research offers a concise and well-structured summary of nanotechnology, which should prove beneficial to researchers, engineers, and scientists embarking on future research endeavors.

Tumor-Homing Peptides as Crucial Component of Magnetic-Based Delivery Systems: Recent Developments and Pharmacoeconomical Perspective

According to data from the World Health Organization (WHO), cancer is considered to be one of the leading causes of death worldwide, and new therapeutic approaches, especially improved novel cancer treatment regimens, are in high demand. Considering that many chemotherapeutic drugs tend to have poor pharmacokinetic profiles, including rapid clearance and limited on-site accumulation, a combined approach with tumor-homing peptide (THP)-functionalized magnetic nanoparticles could lead to remarkable improvements. This is confirmed by an increasing number of papers in this field, showing that the on-target peptide functionalization of magnetic nanoparticles improves their penetration properties and ensures tumor-specific binding, which results in an increased clinical response. This review aims to highlight the potential applications of THPs in combination with magnetic carriers across various fields, including a pharmacoeconomic perspective.

Superparamagnetic Hybrid Nanospheres Based on Chitosan Obtained by Double Crosslinking in a Reverse Emulsion for Cancer Treatment

Nowadays, the Magnetically Targeted Drug Delivery System (MTDDS) is among the most attractive and promising strategies for delivering drugs to the target site. The present study aimed to obtain a biopolymer-magnetite-drug nanosystem via a double crosslinking (ionic and covalent) technique in reverse emulsion, which ensures the mechanical stability of the polymer support in the form of original hybrid nanospheres (NSMs) loaded with biologically active principles (the 5-Fluorouracil (5-FU)) as a potential treatment for cancer. Obtained NSMs were characterized in terms of structure (FT-IR), size (DLS), morphology (SEM), swelling, and 5-FU entrapment/release properties, which were dependent on the synthesis parameters (polymer concentration, dispersion speed, and amount of ionic crosslinking agent). SEM analysis results revealed that NSMs presented a spherical shape and are homogeneous and separated. Moreover, NSMs' ability to load/release 5-FU was tested in vitro, the results confirming, as expected, their dependence on the varied synthesis process and NSM swelling ability in physiological liquids. The drug transport mechanism through the polymer matrix of its release is the Fickian type. The morphological, bio-material characteristics and the ability to include and release an antitumor drug highlight the utility of the NSMs obtained for targeting and treating some tumor diseases.

Advances in Pancreatic Cancer Treatment by Nano-Based Drug Delivery Systems

Pancreatic cancer represents one of the most lethal cancer types worldwide, with a 5-year survival rate of less than 5%. Due to the inability to diagnose it promptly and the lack of efficacy of existing treatments, research and development of innovative therapies and new diagnostics are crucial to increase the survival rate and decrease mortality. Nanomedicine has been gaining importance as an innovative approach for drug delivery and diagnosis, opening new horizons through the implementation of smart nanocarrier systems, which can deliver drugs to the specific tissue or organ at an optimal concentration, enhancing treatment efficacy and reducing systemic toxicity. Varied materials such as lipids, polymers, and inorganic materials have been used to obtain nanoparticles and develop innovative drug delivery systems for pancreatic cancer treatment. In this review, it is discussed the main scientific advances in pancreatic cancer treatment by nano-based drug delivery systems. The advantages and disadvantages of such delivery systems in pancreatic cancer treatment are also addressed. More importantly, the different types of nanocarriers and therapeutic strategies developed so far are scrutinized.

Radiosensitization effect of radiofrequency hyperthermia in the presence of PEGylated-gold nanoparticles on the MCF-7 breast cancer cells under 6 MeV electron irradiation

Purpose

The purpose of the study was to investigate the radiosensitization effect of radiofrequency (RF) hyperthermia in combination with PEGylated gold nanoparticles (PEG-GNPs) on MCF-7 breast cancer cells under electron beam radiotherapy (EBRT) based on the clonogenic assay.

Materials and Methods

The cell death of MCF-7 breast cancer cells treated with 13.56 MHz capacitive RF hyperthermia (power: 150W) for 2, 5, 10, and 15 min combined with 6 MeV EBRT, with a dose of 2 Gy, was evaluated in the presence of 20 nm PEG-GNPs with a low nontoxic concentration (20 mg/l). All the treatment groups were incubated for 14 days. Thereafter, survival fractions and viability of the cells were calculated and analyzed against the control group.

Results

The presence of PEG-GNPs inside the MCF-7 cancer cells during electron irradiation decreased cell survival significantly (16.7%) compared to irradiated cells without GNPs. Applying hyperthermia before electron irradiation with a capacitive RF system decreased cell survival by about 53.7%, while hyperthermia without irradiation did not show any significant effect on cell survival. Combining the hyperthermia with the presence of PEG-GNPs in the cells decreased the cell survival by about 67% at the electron irradiation, showing their additive radiosensitization effect.

Conclusion

Low nontoxic concentration of 20 nm PEG-GNPs increases the radiosensitization effect of combining 6 MeV EBRT and RF hyperthermia on MCF-7 cancer cells. Combining hyperthermia with PEG-GNPs in electron radiotherapy could be an appropriate method for enhancing radiotherapy effectiveness on cancerous cells which can be studied on different cells and electron energies in future research.

Craniofacial therapy: advanced local therapies from nano-engineered titanium implants to treat craniofacial conditions

Nano-engineering-based tissue regeneration and local therapeutic delivery strategies show significant potential to reduce the health and economic burden associated with craniofacial defects, including traumas and tumours. Critical to the success of such nano-engineered non-resorbable craniofacial implants include load-bearing functioning and survival in complex local trauma conditions. Further, race to invade between multiple cells and pathogens is an important criterion that dictates the fate of the implant. In this pioneering review, we compare the therapeutic efficacy of nano-engineered titanium-based craniofacial implants towards maximised local therapy addressing bone formation/resorption, soft-tissue integration, bacterial infection and cancers/tumours. We present the various strategies to engineer titanium-based craniofacial implants in the macro-, micro- and nano-scales, using topographical, chemical, electrochemical, biological and therapeutic modifications. A particular focus is electrochemically anodised titanium implants with controlled nanotopographies that enable tailored and enhanced bioactivity and local therapeutic release. Next, we review the clinical translation challenges associated with such implants. This review will inform the readers of the latest developments and challenges related to therapeutic nano-engineered craniofacial implants.

Glutamate from nerve cells promotes perineural invasion in pancreatic cancer by regulating tumor glycolysis through HK2 mRNA-m6A modification

BACKGROUND

Perineural invasion (PNI) has a high incidence and poor prognosis in pancreatic ductal adenocarcinoma (PDAC). Our study aimed to identify the underlying molecular mechanism of PNI and propose effective intervention strategies.

METHODS

To observe PNI in vitro and in vivo, a Matrigel/ dorsal root ganglia (DRG) model and a murine sciatic nerve invasion model were respectively used. Magnetic resonance (MR) imaging and positron emission tomography/computed tomography (PET-CT) imaging were also used to evaluate tumor growth. Publicly available datasets and PDAC tissues were used to verify how the nerve cells regulate PDAC cells' PNI.

RESULTS

Our results showed that glutamate from nerve cells could cause calcium influx in PDAC cells via the N-methyl-d-aspartate receptor (NMDAR), subsequently activating the downstream Ca²⁺ dependent protein kinase CaMKII/ERK-MAPK pathway and promoting the mRNA transcription of gene METTL3. Next, METTL3 upregulates the expression of hexokinase 2 (HK2) through N6-methyladenosine (m6A) modification in mRNA, enhances the PDAC cells' glycolysis, and promotes PNI. Furthermore, the IONPs-PEG-scFvCD44v6-scAbNMDAR2B nanoparticles dual targeting CD44 variant isoform 6 (CD44v6) and t NMDAR subunit 2B (NMDAR2B) on PDAC cells were synthesized and verified showing a satisfactory blocking effect on PNI.

CONCLUSIONS

Here, we firstly provided evidence that glutamate from the nerve cells could upregulate the expression of HK2 through mRNA m6A modification via NMDAR2B and downstream Ca²⁺ dependent CaMKII/ERK-MAPK pathway, enhance the glycolysis in PDAC cells, and ultimately promote PNI. In addition, the dual targeting nanoparticles we synthesized were verified to block PNI effectively in PDAC.

Plant-inspired Pluronic-gallol micelles with low critical micelle concentration, high colloidal stability, and protein affinity

Polymeric micelles are the most common carriers used for hydrophobic drug delivery. However, they are vulnerable to physiological barriers, such as temperature changes and enzymatic degradation, and can be easily disassembled upon dilution below the critical micelle concentration (CMC) by body fluids after an intravenous injection. Here, we report that Pluronic® micelles with octyl gallate, which is a surfactant containing gallol moieties widely found in antioxidative plant polyphenols, have a low CMC, which improves their colloidal stability without the need for covalent crosslinking. Furthermore, the incorporated gallol moieties provide enzymatic degradation resistance to the micelles owing to their protein affinity, maintaining the hydrophobic cavity of unmodified Pluronic®. Thus, plant-inspired polymeric micelles with low CMC and bioavailability are promising multifunctional vehicles for drug delivery.

Emerging Applications of Nanotechnology in Healthcare Systems: Grand Challenges and Perspectives

Healthcare, as a basic human right, has often become the focus of the development of innovative technologies. Technological progress has significantly contributed to the provision of high-quality, on-time, acceptable, and affordable healthcare. Advancements in nanoscience have led to the emergence of a new generation of nanostructures. Each of them has a unique set of properties that account for their astonishing applications. Since its inception, nanotechnology has continuously affected healthcare and has exerted a tremendous influence on its transformation, contributing to better outcomes. In the last two decades, the world has seen nanotechnology taking steps towards its omnipresence and the process has been accelerated by extensive research in various healthcare sectors. The inclusion of nanotechnology and its allied nanocarriers/nanosystems in medicine is known as nanomedicine, a field that has brought about numerous benefits in disease prevention, diagnosis, and treatment. Various nanosystems have been found to be better candidates for theranostic purposes, in contrast to conventional ones. This review paper will shed light on medically significant nanosystems, as well as their applications and limitations in areas such as gene therapy, targeted drug delivery, and in the treatment of cancer and various genetic diseases. Although nanotechnology holds immense potential, it is yet to be exploited. More efforts need to be directed to overcome these limitations and make full use of its potential in order to revolutionize the healthcare sector in near future.

Targeted nanomedicine modalities for prostate cancer treatment

Prostate cancer (PC) is the second most common cause of death amongst men in the USA. Therapy of PC has been transformed in the past decade by introducing novel therapeutics, advanced functional imaging and diagnostic approaches, next generation sequencing, as well as improved application of existing therapies in localized PC. Treatment of PC at the different stages of the disease may include surgery, androgen deprivation therapy (ADT), chemotherapy and radiation therapy. However, although ADT has proven efficacious in PC treatment, its effectiveness may be temporary, as these tumors frequently develop molecular mechanisms of therapy resistance, which allow them to survive and proliferate even under conditions of testosterone deprivation, inhibition of androgen receptor signaling, or cytotoxic drug treatment. Importantly, ADT was found to induce key alterations which frequently result in the formation of metastatic tumors displaying a therapy refractory phenotype. Hence, to overcome these serious therapeutic impediments, novel PC cell-targeted therapeutic strategies are being developed. These include diverse platforms enabling specific enhanced antitumor drug uptake and increased intracellular accumulation. Studies have shown that these novel treatment modalities lead to enhanced antitumor activity and diminished systemic toxicity due to the use of selective targeting and decreased drug doses. The underlying mechanism of targeting and internalization is based upon the interaction between a selective ligand, conjugated to a drug-loaded nanoparticle or directly to an anti-cancer drug, and a specific plasma membrane biomarker, uniquely overexpressed on the surface of PC cells. Another targeted therapeutic approach is the delivery of unique anti-oncogenic signaling pathway-based therapeutic drugs, which are selectively cytotoxic to PC cells. The current paper reviews PC targeted modalities reported in the past 6 years, and discusses both the advantages and limitations of the various targeted treatment strategies.

Nano-Biomaterials for the Delivery of Therapeutic and Monitoring Cues for Aortic Diseases

The aorta is the largest artery in the body, so any diseases or conditions which could cause damage to the aorta would put patients at considerable and life-threatening risk. In the management of aortic diseases, the major treatments include drug therapy, endovascular treatment, and surgical treatment, which are of great danger or with a poor prognosis. The delivery of nano-biomaterials provides a potential development trend and an emerging field where we could monitor patients’ conditions and responses to the nanotherapeutics. One of the putative applications of nanotechnology is ultrasensitive monitoring of cardiovascular markers by detecting and identifying aneurysms. Moreover, the use of nanosystems for targeted drug delivery can minimize the systemic side effects and enhance drug positioning and efficacy compared to conventional drug therapies. This review shows some examples of utilizing nano-biomaterials in in vitro organ and cell culture experiments and explains some developing technologies in delivering and monitoring regenerative therapeutics.

The Therapeutic Potential of Nanobodies

Today, bio-medical efforts are entering the subcellular level, which is witnessed with the fast-developing fields of nanomedicine, nanodiagnostics and nanotherapy in conjunction with the implementation of nanoparticles for disease prevention, diagnosis, therapy and follow-up. Nanoparticles or nanocontainers offer advantages including high sensitivity, lower toxicity and improved safety—characteristics that are especially valued in the oncology field. Cancer cells develop and proliferate in complex microenvironments leading to heterogeneous diseases, often with a fatal outcome for the patient. Although antibody-based therapy is widely used in the clinical care of patients with solid tumours, its efficiency definitely needs improvement. Limitations of antibodies result mainly from their big size and poor penetration in solid tissues. Nanobodies are a novel and unique class of antigen-binding fragments, derived from naturally occurring heavy-chain-only antibodies present in the serum of camelids. Their superior properties such as small size, high stability, strong antigen-binding affinity, water solubility and natural origin make them suitable for development into next-generation biodrugs. Less than 30 years after the discovery of functional heavy-chain-only antibodies, the nanobody derivatives are already extensively used by the biotechnology research community. Moreover, a number of nanobodies are under clinical investigation for a wide spectrum of human diseases including inflammation, breast cancer, brain tumours, lung diseases and infectious diseases. Recently, caplacizumab, a bivalent nanobody, received approval from the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) for treatment of patients with thrombotic thrombocytopenic purpura.

Antitumoral Drug: Loaded Hybrid Nanocapsules Based on Chitosan with Potential Effects in Breast Cancer Therapy

Cancer remains one of the world's most devastating diseases and is responsible for more than 20% of all deaths. It is defined as uncontrolled proliferation of cells and spreads rapidly to healthy tissue. Controlled drug delivery systems offers great opportunities for the development of new non-invasive strategies for the treatment of cancers. The main advantage of these systems is their capacity to accumulate in tumors via enhanced permeability and retention effects. In the present study, an innovative hybrid drug delivery system based on nanocapsules obtained from the interfacial condensation between chitosan and poly(N-vinyl pyrrolidone-alt-itaconic anhydride) and containing both magnetic nanoparticles and an antitumoral drug was developed in order to improve the efficiency of the antitumoral treatment. Using dynamic light scattering, it was observed that the mean diameter of these hybrid nanocapsules was in the range of 43 to 142 nm. SEM confirmed their nanometric size and their well-defined spherical shape. These nanocapsules allowed the encapsulation of an increased amount of 5-fluorouracil and provided controlled drug release. In vitro studies have revealed that these drug-loaded hybrid nanocapsules were able to induce a cytostatic effect on breast carcinoma MCF-7 cell lines (Human Caucasian breast adenocarcinoma - HTB-22) comparable to that of the free drug.

The programmed site-specific delivery of the angiostatin sunitinib and chemotherapeutic paclitaxel for highly efficient tumor treatment

Malignant solid tumors are composed of tumor cells, stromal cells and the complex networks of the tumor microenvironment (TME), which is the underlying cause of the unsatisfactory outcome of conventional chemotherapy approaches only aimed at cancer cell killing. In this study, a novel TME-responsive polymeric micelle has been developed for the programmed site-specific delivery of the angiostatin sunitinib and chemotherapeutic paclitaxel (PTX). The pH-sensitive micelle core encapsulates PTX, while β-cyclodextrin molecules being conjugated to the micelle shell via matrix metalloproteinase 2 (MMP-2) sensitive peptides include sunitinib. Following the pH and MMP-2 dual sensitive structure design, the micelle may sequentially release sunitinib inside the tumor extracellular matrix and PTX into cancer cells through responding to enriched MMP-2 levels and decreased pH, respectively. Consequently, the anti-angiogenesis effect of sunitinib and tumor cell-killing effect of PTX synergize, resulting in highly efficient tumor treatment.

pH-Responsive Lignin-Based Nanomicelles for Oral Drug Delivery

A pH-stimuli amphiphilic lignin-based copolymer was prepared, and it could self-assemble to form spherical nanomicelles with the addition of "switching" water. The morphology, structure, and physical properties of micelles were characterized with transmission electron microscopy (TEM), nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), particle-size analysis, and zeta-potential measurement. In vitro drug release exemplified that the micelles were pH-sensitive, retaining more than 84.36% ibuprofen (IBU) in simulated gastric fluid (pH 1.5) and presenting a smooth release of 81.81% IBU in simulated intestinal fluid (pH 7.4) within 72 h. Cell culture studies showed that the nanomicelles were biocompatible and boosted the proliferation of human bone marrow stromal cells hBMSC and mouse embryonic fibroblast cells NIH-3T3. Interestingly, the nanomicelles inhibited the survival of human colon cancer cells HT-29 with a final survival rate of only 5.34%. Therefore, this work suggests a novel strategy to synthesize intelligent lignin-based nanomicelles that show a great potential as oral drug carriers.

Toxicity of Carbon Nanotubes as Anti-Tumor Drug Carriers

Nanoparticle drug formulations have enormous application prospects owing to achievement of targeted and sustained release drug delivery, improvement in drug solubility and reduction of adverse drug reactions. Recently, a variety of efficient drug nanometer carriers have been developed, among which carbon nanotubes (CNT) have been increasingly utilized in the field of cancer therapy. However, these nanotubes exert various toxic effects on the body due to their unique physical and chemical properties. CNT-induced toxicity is related to surface modification, degree of aggregation in vivo, and nanoparticle concentration. This review has focused on the potential toxic effects of CNTs utilized as anti-tumor drug carriers. The main modes by which CNTs enter target sites, the toxicity expressive types and the factors affecting toxicity are discussed.

Diaphragmatic recovery in rats with cervical spinal cord injury induced by a theophylline nanoconjugate: Challenges for clinical use

Context: Following a spinal cord hemisection at the second cervical segment the ipsilateral hemidiaphragm is paralyzed due to the disruption of the rostral ventral respiratory group (rVRG) axons descending to the ipsilateral phrenic motoneurons (PN). Systemically administered theophylline activates a functionally latent crossed phrenic pathway (CPP) which decussates caudal to the hemisection and activates phrenic motoneurons ipsilateral to the hemisection. The result is return of function to the paralyzed hemidiaphragm. Unfortunately, in humans, systemically administered theophylline at a therapeutic dose produces many unwanted side effects.Design and setting: A tripartite nanoconjugate was synthesized in which theophylline was coupled to a neuronal tracer, wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP), using gold nanoparticles as the coupler. Following intradiaphragmatic injection of the nanoconjugate, WGA-HRP selectively targets the theophylline-bound nanoconjugate to phrenic motoneurons initially, followed by neurons in the rVRG by retrograde transsynaptic transport.Participants: (N/A)Interventions: (N/A)Outcome Measures: Immunostaining, Electromyography (EMG).Results: Delivery of the theophylline-coupled nanoconjugate to the nuclei involved in respiration induces a return of respiratory activity as detected by EMG of the diaphragm and a modest return of phrenic nerve activity.Conclusion: In addition to the modest return of phrenic nerve activity, there were many difficulties using the theophylline nanoconjugate because of its chemical instability, which suggests that the theophylline nanoconjugate should not be developed for clinical use as explained herein.

Cancer Therapy Based on Smart Drug Delivery with Advanced Nanoparticles

Background:

Cancer, as one of the most dangerous disease, causes millions of deaths every year. The main reason is the absence of an effective and thorough treatment. Drug delivery systems have significantly reduced the side-effect of chemotherapy. Combined with nanotechnology, smart drug delivery systems including many different nanoparticles can reduce the side-effect of chemotherapy better than traditional drug delivery systems.

Methods:

In this article, we will describe in detail the different kinds of nanoparticles and their mechanisms emphasizing the triggering factors in drug delivery. Besides, the application of smart drug delivery systems in imaging will be introduced.

Results:

Combined with nanotechnology, smart drug delivery systems including many different nanoparticles can reduce the side-effect of chemotherapy better than traditional drug delivery systems.

Conclusion:

Despite considerable progress in nanoparticle research over the past decade, such as smart drug delivery systems for the treatment of cancer, molecular imaging probes and the like. The range of nanoparticles used in multifunction systems for imaging and drug delivery continues to grow and we expect this dilatation to continue. But to make nanoparticles truly a series of clinical products to complement and replace current tools, constant exploration efforts and time are required. Overall, the future looks really bright.

Nanotechnology Meets Oncology: Nanomaterials in Brain Cancer Research, Diagnosis and Therapy

Advances in technology of the past decades led to development of new nanometer scale diagnosis and treatment approaches in cancer medicine leading to establishment of nanooncology. Inorganic and organic nanomaterials have been shown to improve bioimaging techniques and targeted drug delivery systems. Their favorable physico-chemical characteristics, like small sizes, large surface area compared to volume, specific structural characteristics, and possibility to attach different molecules on their surface transform them into excellent transport vehicles able to cross cell and/or tissue barriers, including the blood–brain barrier. The latter is one of the greatest challenges in diagnosis and treatment of brain cancers. Application of nanomaterials can prolong the circulation time of the drugs and contrasting agents in the brain, posing an excellent opportunity for advancing the treatment of the most aggressive form of the brain cancer—glioblastomas. However, possible unwanted side-effects and toxicity issues must be considered before final clinical translation of nanoparticles.

Delivery of Sesamol Using Polyethylene-Glycol-Functionalized Selenium Nanoparticles in Human Liver Cells in Culture

Anticancer nanoparticles were fabricated by linking the nanoparticles of two known anticancer agents, sesamol and selenium, using polyethylene glycol (PEG). The successful fabrication of the sesamol-PEG-selenium nanoparticles (PEG-SeNPs), which had a sesamol loading efficiency of 10.0 ± 0.5 wt %, was demonstrated using different spectroscopic techniques. The impact of the nanoparticles on model cancer cells (HepG2) was established using the cell activity test, morphological observation, and fluorescent staining, which all showed that nanoparticles effectively inhibited the HepG2 cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays showed that the concentration of the sample that inhibits 50% of the cells of PEG-SeNPs and sesamol-PEG-SeNPs on HepG2 cells was 413.8 and 68.7 μg/mL, respectively, which indicated the synergistic inhibition between sesamol and selenium nanoparticles. Furthermore, flow cytometry showed that sesamol-PEG-SeNPs exhibited higher apoptosis than either sesamol or PEG-SeNPs alone. Finally, western blot confirmed that the apoptostic ability of sesamol-PEG-SeNPs was associated with downregulation of Bcl-2 and procaspase-3, upregulation of Bax and PARP, and discharge of cytochrome c into the cytosol. Our findings suggest the novel sesamol nanoparticles may be efficient anticancer agents.

Size effect of mesoporous organosilica nanoparticles on tumor penetration and accumulation

The size effect of mesoporous organosilica nanoparticles (MONs) on tumor penetration and accumulation remains poorly understood, which strongly affects the tumor therapeutic efficacy.

External stimulus responsive inorganic nanomaterials for cancer theranostics

Cancer is a highly intelligent system of cells, that works together with the body to thrive and subsequently overwhelm the host in order for its survival. Therefore, treatment regimens should be equally competent to outsmart these cells. Unfortunately, it is not the case with current therapeutic practices, the reason why it is still one of the most deadly adversaries and an imposing challenge to healthcare practitioners and researchers alike. With rapid nanotechnological interventions in the medical arena, the amalgamation of diagnostic and therapeutic functionalities into a single platform, theranostics provides a never before experienced hope of enhancing diagnostic accuracy and therapeutic efficiency. Additionally, the ability of these nanotheranostic agents to perform their actions on-demand, i.e. can be controlled by external stimulus such as light, magnetic field, sound waves and radiation has cemented their position as next generation anti-cancer candidates. Numerous reports exist of such stimuli-responsive theranostic nanomaterials against cancer, but few have broken through to clinical trials, let alone clinical practice. This review sheds light on the pros and cons of a few such theranostic nanomaterials, especially inorganic nanomaterials which do not require any additional chemical moieties to initiate the stimulus. The review will primarily focus on preclinical and clinical trial approved theranostic agents alone, describing their success or failure in the respective stages.

The treatment value of IL-1β monoclonal antibody under the targeting location of alpha-methyl-L-tryptophan and superparamagnetic iron oxide nanoparticles in an acute temporal lobe epilepsy model

BACKGROUND

Temporal lobe epilepsy (TLE) is a common and often refractory brain disease that is closely correlated with inflammation. Alpha-methyl-L-tryptophan (AMT) is recognized as a surrogate marker for epilepsy, characterized by high uptake in the epileptic focus. There are many advantages of using the magnetic targeting drug delivery system of superparamagnetic iron oxide nanoparticles (SPIONs) to treat many diseases, including epilepsy. We hypothesized that AMT and an IL-1β monoclonal antibody (anti-IL-1β mAb) chelated to SPIONs would utilize the unique advantages of SPIONs and AMT to deliver the anti-IL-1β mAb across the blood-brain barrier (BBB) as a targeted therapy.

METHODS

Acute TLE was induced in 30 rats via treatment with lithium-chloride pilocarpine. The effects of plain-SPIONs, anti-IL-1β-mAb-SPIONs, or AMT-anti-IL-1β-mAb-SPIONs on seizure onset were assessed 48 h later. Perl's iron staining, Nissl staining, immunofluorescence staining and western blotting were performed after magnetic resonance imaging examination.

RESULTS

The imaging and histopathology in combination with the molecular biology findings showed that AMT-anti-IL-1β-mAb-SPIONs were more likely to penetrate the BBB in the acute TLE model to reach the targeting location and deliver a therapeutic effect than plain-SPIONs and anti-IL-1β-mAb-SPIONs.

CONCLUSIONS

This study demonstrated the significance of anti-IL-1β-mAb treatment in acute TLE with respect to the unique advantages of SPIONs and the active location-targeting characteristic of AMT.

Epidermal Growth Factor Receptor-Targeting Peptide Nanoparticles Simultaneously Deliver Gemcitabine and Olaparib To Treat Pancreatic Cancer with Breast Cancer 2 ( BRCA2) Mutation

Pancreatic cancer (PCa) is one of the most lethal malignancies, with a 5 year survival rate of less than 8%. Current treatment regiments have a low response rate in unselected patients. However, the subgroup of PCa patients with BRCA mutations may benefit from poly-ADP-ribose polymerase inhibitors (PARPi) due to their biological properties in DNA repair. Dose-limiting toxicity in normal tissues is frequently observed when PARPi are combined with other chemotherapies, and the co-delivery of two drugs to tumor sites at an adequate concentration is challenging. To address this issue, we have engineered an epidermal growth factor receptor (EGFR) targeting (with GE11 peptide) self-assembly amphiphilic peptide nanoparticle (GENP) to co-deliver gemcitabine and the PARPi olaparib to treat BRCA mutant PCa. The GENP was relatively stable, exhibited high encapsulation efficiency, and could coordinately release the two drugs in tumor milieu. Gemcitabine and olaparib showed strong synergistic actions in optimized conditions in vitro. The nanoparticle prolonged the half-life of both drugs and resulted in their tumor accumulation at the optimal therapeutic ratio in vivo. The drug-loaded nanoparticles were able to significantly suppress tumor growth in a murine PCa model with minimal side effects. Drug co-delivery of DNA damaging agents and PARP inhibitors via the GENP represents a promising approach for treatment of pancreatic cancers with molecular defects in the DNA repair pathway.

Plasmonic photothermal therapy: Approaches to advanced strategy

BACKGROUND

The analysis of recent studies on plasmonic photothermal therapy (PPT) after intravenous administration of gold nanorods (GNRs) has demonstrated that the effectiveness of nanoparticle-assisted laser hyperthermia depends on a correct dosage strategy of nanoparticle administration. Accumulation of GNRs in tumor tissue dramatically increases the local heating of the tumor without damage to healthy tissues. However, the optimal doses of GNR intravenous injections (IVIs) for effective accumulation in tumors, and optimal protocols of PPT are not designed yet. The current study aims to improve the efficacy of PPT in tumor-bearing rats using multiple fractional intravenous administration of GNRs.

MATERIALS AND METHODS

For PPT experiments, the GNRs with aspect ratio of 4.1 were functionalized with thiolated polyethylene glycol (PEG) and their suspensions were used for multiple fractional intravenous administration in outbred albino male rats with experimental model of rat liver cancer (cholangiocarcinoma line PC-1). Doppler ultrasonography was performed to characterize the vascularity of transplanted rat tumors before any treatment. After a final injection of GNRs, tumor was irradiated during 15 minutes by 808-nm NIR diode laser at a power density 2.3 W/cm² . The animals were withdrawn from the experiment and sampling of tissues for morphological study and gold accumulation was performed 24 hours and 3 weeks after PPT.

RESULTS

The multiple IVIs of gold nanorods and further PPT of transplanted cholangiocarcinoma provided significant damage to tumor tissue resulting in pronounced necrotic mass and retardation of the tumor growth. More importantly, the proposed PPT protocol had low toxicity as evidenced by histological examination of internal organs. The efficiency of PPT depends on the presence of newly formed vasculature as revealed by the Doppler ultrasound investigation.

CONCLUSION

The repeatable IVIs promote greater of GNR accumulation within the tumor thus resulting in higher PPT efficacy. Accompanying ultrasonography can be useful for prognosis and monitoring of treatment. Lasers Surg. Med. 50:1025-1033, 2018. © 2018 Wiley Periodicals, Inc.

Liposomal 64Cu-PET Imaging of Anti-VEGF Drug Effects on Liposomal Delivery to Colon Cancer Xenografts

Liposomes (LP) deliver drug to tumors due to enhanced permeability and retention (EPR). LP were labeled with ⁶⁴Cu for positron emission tomography (PET) to image tumor localization. Bevacizumab (bev), a VEGF targeted antibody, may modify LP delivery by altering tumor EPR and this change can also be imaged.

Objective: Assess the utility of ⁶⁴Cu-labeled LP for PET in measuring altered LP delivery early after treatment with bev.

Methods: HT-29 human colorectal adenocarcinoma tumors were grown subcutaneously in SCID mice. Empty LP MM-DX-929 (Merrimack Pharmaceuticals, Inc. Cambridge, MA) were labeled with ⁶⁴CuCl₂ chelated with 4-DEAP-ATSC. Tumor-bearing mice received ~200-300 μCi of ⁶⁴Cu-MM-DX-929 and imaged with microPET. All mice were scanned before and after the treatment period, in which half of the mice received bev for one week. Scans were compared for changes in LP accumulation during this time. Initially, tissues were collected after the second PET for biodistribution measurements and histological analysis. Subsequent groups were divided for further treatment. Tumor growth following bev treatment, with or without LP-I, was assessed compared to untreated controls.

Results: PET scans of untreated mice showed increased uptake of ⁶⁴Cu-MM-DX-929, with a mean change in tumor SUV_max of 43.9%±6.6% (n=10) after 7 days. Conversely, images of treated mice showed that liposome delivery did not increase, with changes in SUV_max of 7.6%±4.8% (n=12). Changes in tumor SUV_max were significantly different between both groups (p=0.0003). Histology of tumor tissues indicated that short-term bev was able to alter vessel size. Therapeutically, while bev monotherapy, LP-I monotherapy, and treatment with bev followed by LP-I all slowed HT-29 tumor growth compared to controls, combination provided no therapeutic benefit.

Conclusions: PET with tracer LP ⁶⁴Cu-MM-DX-929 can detect significant differences in LP delivery to colon tumors treated with bev when compared to untreated controls. Imaging with ⁶⁴Cu-MM-DX-929 is sensitive enough to measure drug-induced changes in LP localization which can have an effect on outcomes of treatment with LP.

Quantum dots: from fluorescence to chemiluminescence, bioluminescence, electrochemiluminescence, and electrochemistry

During the past decade, nanotechnology has become one of the major forces driving basic and applied research. As a novel class of inorganic fluorochromes, research into quantum dots (QDs) has become one of the fastest growing fields of nanotechnology today. QDs are made of a semiconductor material with tunable physical dimensions as well as unique optoelectronic properties, and have attracted multidisciplinary research efforts to further their potential bioanalytical applications. Recently, numerous optical properties of QDs, such as narrow emission band peaks, broad absorption spectra, intense signals, and remarkable resistance to photobleaching, have made them biocompatible and sensitive for biological assays. In this review, we give an overview of these exciting materials and describe their potential, especially in biomolecules analysis, including fluorescence detection, chemiluminescence detection, bioluminescence detection, electrochemiluminescence detection, and electrochemical detection. Finally, conclusions are made, including highlighting some critical challenges remaining and a perspective of how this field can be expected to develop in the future.

A multifunctional lipid nanoparticle for co-delivery of paclitaxel and curcumin for targeted delivery and enhanced cytotoxicity in multidrug resistant breast cancer cells

The objective of the work was to develop a multifunctional nanomedicine based on a folate-conjugated lipid nanoparticles loaded with paclitaxel and curcumin. The novel system combines therapeutic advantageous of efficient targeted delivery via folate and timed-release of curcumin and paclitaxel via 2-hydroxypropyl-ß-cyclodextrin, thereby overcoming multidrug resistance in breast cancer cells (MCF-7/ADR). The faster release of curcumin from the folate-conjugated curcumin and paclitaxel-loaded lipid nanoparticles enables sufficient p-glycoprotein inhibition, which allows increased cellular uptake and cytotoxicity of paclitaxel. In western blot assay, curcumin can efficiently inhibit the expression of p-glycoprotein, conformed the enhancement of cytotoxicity by paclitaxel. Furthermore, folate-conjugated curcumin and paclitaxel-loaded lipid nanoparticles exhibited increased uptake of paclitaxel and curcumin into MCF-7/ADR cells through the folate receptor-mediated internalization. Taken together, these results indicate that folate-conjugated curcumin and paclitaxel-loaded lipid nanoparticles enables the enhanced, folate-targeted delivery of multiple anticancer drugs by inhibiting the multi-drug resistance efficiently, which may also serve as a useful nano-system for co-delivery of other anticancer drugs.

Formation and Stability of Bulk Nanobubbles Generated by Ethanol-Water Exchange

Bulk nanobubbles have unique properties and find potential applications in many important processes. However, their stability or long lifetime still needs to be understood and has attracted much attention from researchers. Bulk nanobubbles are generated based on ethanol-water exchange, a method that is generally used in the study of surface nanobubbles. Their formation and stability is further studied by using a new type of dynamic light scattering known as NanoSight. The results show that the concentration of the bulk nanobubbles produced by this method is about five times greater than that in the degassed group, which indicates the existence of bulk gas nanobubbles. The effects of ethanol/water ratios and temperature on the stability of the bulk nanobubbles have also been studied and their numbers reach a maximum at a ratio of about 1:10 (v/v).

Use of Nanoparticles As Contrast Agents for the Functional and Molecular Imaging of Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is a degenerative disease of the aorta common in adults older than 65 years of age. AAA is usually imaged using ultrasound or computed tomography. Molecular imaging technologies employing nanoparticles (NPs) have been proposed as novel ways to quantify pathological processes, such as inflammation, within AAAs as a means to identify the risk of rapid progression or rupture. This article reviews the current evidence supporting the role of NP-based imaging in the management of AAA. Currently, ultrasmall superparamagnetic NPs enhanced magnetic resonance imaging appears to hold the greatest potential for imaging macrophage-mediated inflammation in human AAA.

Methods for Generation and Detection of Nonstationary Vapor Nanobubbles Around Plasmonic Nanoparticles

Laser pulse-induced vapor nanobubbles are nonstationary nanoevents that offer a broad range of applications, especially in the biomedical field. Plasmonic (usually gold) nanoparticles have the highest energy efficacy of the generation of vapor nanobubbles and such nanobubbles were historically named as plasmonic nanobubbles. Below we review methods (protocols) for generating and detecting plasmonic nanobubbles in liquids. The biomedical applications of plasmonic nanobubbles include in vivo and in vitro detection and imaging, gene transfer, micro-surgery, drug delivery, and other diagnostic, therapeutic, and theranostic applications.

Synthesis, characterization, DNA binding, cleavage activity, cytotoxicity and molecular docking of new nano water-soluble [M(5-CH₂PPh₃-3,4-salpyr)](ClO₄)₂ (M = Ni, Zn) complexes

Some new water soluble complexes [N,N'-bis{5-[(triphenyl phosphonium chloride)-methyl]salicylidine}-3,4-diaminopyridine] M(ii), which are formulated as nano-[Zn(5-CH2PPh3-3,4-salpyr)](ClO4)2 (), [Zn(5-CH2PPh3-3,4-salpyr)](ClO4)2 (), nano-[Ni(5-CH2PPh3-3,4-salpyr)](ClO4)2 (), [Ni(5-CH2PPh3-3,4-salpyr)](ClO4)2 (), and [N,N'-bis{5-[(triphenyl phosphonium chloride)-methyl]salicylidine}-2,3-diaminopyridine]Ni(ii) [Ni(5-CH2PPh3-2,3-salpyr)](ClO4)2 () have been isolated and characterized by elemental analysis, FT-IR, (1)H NMR, (13)C NMR, (31)P NMR, and UV-vis spectroscopy. The morphology and size of the nano complexes were determined using FE-SEM and TEM. In vitro DNA binding studies were investigated by UV-vis absorption spectroscopy, viscosity measurements, CD spectroscopy, cyclic voltammetry, emission spectra and gel electrophoresis, which suggest that the metal complexes act as efficient DNA binders. The absorption spectroscopy of the compounds with DNA reveals that the DNA binding affinity (Kb) has this order: > > > > > Ligand. The metal complexes show DNA binding stronger than the ligand, which is expected due to the nature of the metal. The nano complexes display DNA binding stronger than the other complexes which is related to the effect of size on binding affinity and the Ni(ii) complexes reveal DNA binding stronger than the corresponding Zn(ii) analogues, which is expected due to their z* effect and geometry. The prominent double strand DNA cleavage abilities of compound are observed in the absence of H2O2 with efficiencies of more than 50% even at 70 μM complex concentration. Surprisingly, Zn(ii) complexes (compounds & ) exhibit a higher cytotoxicity (IC50: 7.3 & 10.9 μM at 24 h; IC50: 4.6 & 8.7 μM at 48 h) against human hepatoma (HepG2) and HeLa cell lines than the Ni(ii) complexes (compounds , & ) and 5-fluorouracil as control in spite of their inability to cleave DNA. Finally, DNA binding interactions were performed by docking studies. Density functional theory (DFT) studies were performed using the GAUSSIAN 03 program. The DFT method with B3LYP functional, LANL2DZ basis set for metal centers and 6-311g* for other atoms was used. The synthesized compounds and DNA were simulated by molecular docking to explore more details of the ligands conformation and their orientations in the active site of the receptor.

Tumor-targeted nanotherapeutics: overcoming treatment barriers for glioblastoma

Glioblastoma (GBM) is a highly aggressive and lethal form of primary brain cancer. Numerous barriers exist to the effective treatment of GBM including the tightly controlled interface between the bloodstream and central nervous system termed the 'neurovascular unit,' a narrow and tortuous tumor extracellular space containing a dense meshwork of proteins and glycosaminoglycans, and genomic heterogeneity and instability. A major goal of GBM therapy is achieving sustained drug delivery to glioma cells while minimizing toxicity to adjacent neurons and glia. Targeted nanotherapeutics have emerged as promising drug delivery systems with the potential to improve pharmacokinetic profiles and therapeutic efficacy. Some of the key cell surface molecules that have been identified as GBM targets include the transferrin receptor, low-density lipoprotein receptor-related protein, α_v β₃ integrin, glucose transporter(s), glial fibrillary acidic protein, connexin 43, epidermal growth factor receptor (EGFR), EGFR variant III, interleukin-13 receptor α chain variant 2, and fibroblast growth factor-inducible factor 14. However, most targeted therapeutic formulations have yet to demonstrate improved efficacy related to disease progression or survival. Potential limitations to current targeted nanotherapeutics include: (1) adhesive interactions with nontarget structures, (2) low density or prevalence of the target, (3) lack of target specificity, and (4) genetic instability resulting in alterations of either the target itself or its expression level in response to treatment. In this review, we address these potential limitations in the context of the key GBM targets with the goal of advancing the understanding and development of targeted nanotherapeutics for GBM. WIREs Nanomed Nanobiotechnol 2017, 9:e1439. doi: 10.1002/wnan.1439 For further resources related to this article, please visit the WIREs website.

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.

A multifunctional poly(curcumin) nanomedicine for dual-modal targeted delivery, intracellular responsive release, dual-drug treatment and imaging of multidrug resistant cancer cells

A multifunctional anti-cancer nanomedicine based on a biotin-poly(ethylene glycol)-poly(curcumin-dithio dipropionic acid) (Biotin-PEG-PCDA) polymeric nanocarrier loaded with paclitaxel (PTX), magnetic nanoparticles (MNPs) and quantum dots (QDs) is developed. It combines advantageous properties of efficient targeted delivery and uptake (via biotin and MNP), intracellular responsive release (via cleavable PCDA polymer), fluorescence imaging (via QD) and combined PTX-curcumin dual-drug treatment, allowing for overcoming drug resistance mechanisms of model multidrug resistant breast cancer cells (MCF-7/ADR). The PTX/MNPs/QDs@Biotin-PEG-PCDA nanoparticles are highly stable under physiological conditions, but are quickly disassembled to release their drug load in the presence of 10 mM glutathione (GSH). The nanoparticles show high uptake by tumour cells from a combined effect of magnet targeting and biotin receptor-mediated internalization. Moreover, curcumin, an intracellularly cleaved product of PCDA, can effectively down regulate the expression of drug efflux transporters such as P-glycoprotein (P-gp) to increase PTX accumulation within target cancer cells, thereby enhancing PTX induced cytotoxicity and therapeutic efficacy against MCF-7/ADR cells. Taken together, this novel tumour-targeting and traceable multifunctional nanomedicine is highly effective against model MDR cancer at the cellular level.

Evaluation of toxic effects of CdTe quantum dots on the reproductive system in adult male mice

Fluorescent quantum dots (QDs) are highly promising nanomaterials for various biological and biomedical applications because of their unique optical properties, such as robust photostability, strong photoluminescence, and size-tunable fluorescence. Several studies have reported the in vivo toxicity of QDs, but their effects on the male reproduction system have not been examined. In this study, we investigated the reproductive toxicity of cadmium telluride (CdTe) QDs at a high dose of 2.0 nmol per mouse and a low dose of 0.2 nmol per mouse. Body weight measurements demonstrated there was no overt toxicity for both dose at day 90 after exposure, but the high dose CdTe affected body weight up to 15 days after exposure. CdTe QDs accumulated in the testes and damaged the tissue structure for both doses on day 90. Meanwhile, either of two CdTe QDs treatments did not significantly affect the quantity of sperm, but the high dose CdTe significantly decreased the quality of sperm on day 60. The serum levels of three major sex hormones were also perturbed by CdTe QDs treatment. However, the pregnancy rate and delivery success of female mice that mated with the treated male mice did not differ from those mated with untreated male mice. These results suggest that CdTe QDs can cause testes toxicity in a dose-dependent manner. The low dose of CdTe QDs is relatively safe for the reproductive system of male mice. Our preliminary result enables better understanding of the reproductive toxicity induced by cadmium-containing QDs and provides insight into the safe use of these nanoparticles in biological and environmental systems.

The Extraordinary Progress in Very Early Cancer Diagnosis and Personalized Therapy: The Role of Oncomarkers and Nanotechnology

The impact of nanotechnology on oncology is revolutionizing cancer diagnosis and therapy and largely improving prognosis. This is mainly due to clinical translation of the most recent findings in cancer research, that is, the application of bio- and nanotechnologies. Cancer genomics and early diagnostics are increasingly playing a key role in developing more precise targeted therapies for most human tumors. In the last decade, accumulation of basic knowledge has resulted in a tremendous breakthrough in this field. Nanooncology, through the discovery of new genetic and epigenetic biomarkers, has facilitated the development of more sensitive biosensors for early cancer detection and cutting-edge multifunctionalized nanoparticles for tumor imaging and targeting. In the near future, nanooncology is expected to enable a very early tumor diagnosis, combined with personalized therapeutic approaches.

Polymeric Nanoparticles for Cancer Photodynamic Therapy

In chemotherapy a fine balance between therapeutic and toxic effects needs to be found for each patient, adapting standard combination protocols each time. Nanotherapeutics has been introduced into clinical practice for treating tumors with the aim of improving the therapeutic outcome of conventional therapies and of alleviating their toxicity and overcoming multidrug resistance. Photodynamic therapy (PDT) is a clinically approved, minimally invasive procedure emerging in cancer treatment. It involves the administration of a photosensitizer (PS) which, under light irradiation and in the presence of molecular oxygen, produces cytotoxic species. Unfortunately, most PSs lack specificity for tumor cells and are poorly soluble in aqueous media, where they can form aggregates with low photoactivity. Nanotechnological approaches in PDT (nanoPDT) can offer a valid option to deliver PSs in the body and to solve at least some of these issues. Currently, polymeric nanoparticles (NPs) are emerging as nanoPDT system because their features (size, surface properties, and release rate) can be readily manipulated by selecting appropriate materials in a vast range of possible candidates commercially available and by synthesizing novel tailor-made materials. Delivery of PSs through NPs offers a great opportunity to overcome PDT drawbacks based on the concept that a nanocarrier can drive therapeutic concentrations of PS to the tumor cells without generating any harmful effect in non-target tissues. Furthermore, carriers for nanoPDT can surmount solubility issues and the tendency of PS to aggregate, which can severely affect photophysical, chemical, and biological properties. Finally, multimodal NPs carrying different drugs/bioactive species with complementary mechanisms of cancer cell killing and incorporating an imaging agent can be developed. In the following, we describe the principles of PDT use in cancer and the pillars of rational design of nanoPDT carriers dictated by tumor and PS features. Then we illustrate the main nanoPDT systems demonstrating potential in preclinical models together with emerging concepts for their advanced design.

New synthesis and biodistribution of the D-amino acid oxidase-magnetic nanoparticle system

Background:

Application of nanoenzymes, based on D-amino acid oxidase (DAAO) conjugated to magnetic nanoparticles (NPs), as anticancer system requires improvement of the synthesis protocol and in vivo distribution evaluation.

Results:

A new and more efficient synthesis via EDC-NHS produced an Fe₃O₄NP-APTES-DAAO system with a specific activity of 7 U/mg NPs. IR spectroscopy showed that all Fe₃O₄ NP sites are saturated with APTES and all available NH₂ sites with DAAO. The acute cytotoxicity of the new system does not differ from that of the previous one. In vivo experiments showed that the system did not cause adverse effects, cross the brain–blood barrier and accumulate in the heart.

Conclusions:

Our results support the possibility to use enzymes conjugated to magnetic NPs for cancer treatment. Besides, we think that enzymes and other biological molecules efficiently conjugated to magnetic NPs might constitute a category of ‘bionanoparticles’ to be exploited, not only in medical, but also in industrial biotechnology.

Lay abstract: We have linked magnetic nanoparticles to D-amino acid oxidase, an enzyme capable of producing, in the presence of its substrate, reactive oxygen species. The scope is to use the magnetic properties of the enzyme-nanoparticle system to direct it to a desired area where its cytotoxicity can be controlled by the addition of exogenous substrate. Besides the possible applications in cancer therapy, we think that enzymes and other biological molecules linked to magnetic nanoparticles might also be exploited in industrial biotechnology.