Nanomedicine for Spontaneous Brain Tumors: A Companion Clinical Trial

Receptor Ligand-Free Mesoporous Silica Nanoparticles: A Streamlined Strategy for Targeted Drug Delivery across the Blood-Brain Barrier

Mesoporous silica nanoparticles (MSNs) represent a promising avenue for targeted brain tumor therapy. However, the blood-brain barrier (BBB) often presents a formidable obstacle to efficient drug delivery. This study introduces a ligand-free PEGylated MSN variant (RMSN25-PEG-TA) with a 25 nm size and a slight positive charge, which exhibits superior BBB penetration. Utilizing two-photon imaging, RMSN25-PEG-TA particles remained in circulation for over 24 h, indicating significant traversal beyond the cerebrovascular realm. Importantly, DOX@RMSN25-PEG-TA, our MSN loaded with doxorubicin (DOX), harnessed the enhanced permeability and retention (EPR) effect to achieve a 6-fold increase in brain accumulation compared to free DOX. In vivo evaluations confirmed the potent inhibition of orthotopic glioma growth by DOX@RMSN25-PEG-TA, extending survival rates in spontaneous brain tumor models by over 28% and offering an improved biosafety profile. Advanced LC-MS/MS investigations unveiled a distinctive protein corona surrounding RMSN25-PEG-TA, suggesting proteins such as apolipoprotein E and albumin could play pivotal roles in enabling its BBB penetration. Our results underscore the potential of ligand-free MSNs in treating brain tumors, which supports the development of future drug-nanoparticle design paradigms.

Interplay of Oxidative Stress, Inflammation, and Autophagy in RAW 264.7 Murine Macrophage Cell Line Challenged with Si/SiO2 Quantum Dots

Quantum dots (QDs) with photostable fluorescence are recommended for imaging applications; however, their effect on living cells is incompletely understood. We aimed to elucidate the RAW 264.7 murine macrophage cell line's response to the Si/SiO₂ QDs challenge. Cells were exposed to 5 and 15 μg/mL Si/SiO₂ QDs for 6 h, 12 h, and 24 h. Cell metabolic activity and viability were assessed by MTT, live/dead, and dye-exclusion assays. Oxidative stress and membrane integrity were assessed by anion superoxide, malondialdehyde, and lactate dehydrogenase activity evaluations. Antioxidative enzyme activities were analyzed by kinetic spectrophotometric methods. Cytokines were analyzed with an antibody-based magnetic bead assay, PGE2 was assessed by ELISA, and Nrf-2, Bcl-2, Beclin 1, and the HSPs were analyzed by western blot. Autophagy levels were highlighted by fluorescence microscopy. The average IC50 dose for 6, 12, and 24 h was 16.1 ± 0.7 μg/mL. Although glutathione S-transferase and catalase were still upregulated after 24 h, superoxide dismutase was inhibited, which together allowed the gradual increase of malondialdehyde, anion superoxide, nitric oxide, and the loss of membrane integrity. G-CSF, IL-6, TNF-α, MIP-1β, MCP-1, Nrf-2, PGE2, and RANTES levels, as well as autophagy processes, were increased at all time intervals, as opposed to caspase 1 activity, COX-2, HSP60, and HSP70, which were only upregulated at the 6-h exposure interval. These results underscore that Si/SiO₂ QDs possess significant immunotoxic effects on the RAW 264.7 macrophage cell line and stress the importance of developing effective strategies to mitigate their adverse impact.

Silica nanoparticles for brain cancer

INTRODUCTION

Brain cancer is a debilitating disease with a poor survival rate. There are significant challenges for effective treatment due to the presence of the blood-brain barrier (BBB) and blood-tumor barrier (BTB) which impedes drug delivery to tumor sites. Many nanomedicines have been tested in improving both the survival and quality of life of patients with brain cancer with the recent focus on inorganic nanoparticles such as silica nanoparticles (SNPs). This review examines the use of SNPs as a novel approach for diagnosing, treating, and theranostics of brain cancer.

AREAS COVERED

The review provides an overview of different brain cancers and current therapies available. A special focus on the key functional properties of SNPs is discussed which makes them an attractive material in the field of onco-nanomedicine. Strategies to overcome the BBB using SNPs are analyzed. Furthermore, recent advancements in active targeting, combination therapies, and innovative nanotherapeutics utilizing SNPs are discussed. Safety considerations, toxicity profiles, and regulatory aspects are addressed to provide an understanding of SNPs' translational potential.

EXPERT OPINION

SNPs have tremendous prospects in brain cancer research. The multifunctionality of SNPs has the potential to overcome both the BBB and BTB limitations and can be used for brain cancer imaging, drug delivery, and theranostics. The insights provided will facilitate the development of next-generation, innovative strategies, guiding future research toward improved diagnosis, targeted therapy, and better outcomes in brain cancer patients.

The Blood-Brain Barrier: Implications for Experimental Cancer Therapeutics

The blood-brain barrier is critically important for the treatment of both primary and metastatic cancers of the central nervous system (CNS). Clinical outcomes for patients with primary CNS tumors are poor and have not significantly improved in decades. As treatments for patients with extracranial solid tumors improve, the incidence of CNS metastases is on the rise due to suboptimal CNS exposure of otherwise systemically active agents. Despite state-of-the art surgical care and increasingly precise radiation therapy, clinical progress is limited by the ability to deliver an effective dose of a therapeutic agent to all cancerous cells. Given the tremendous heterogeneity of CNS cancers, both across cancer subtypes and within a single tumor, and the range of diverse therapies under investigation, a nuanced examination of CNS drug exposure is needed. With a shared goal, common vocabulary, and interdisciplinary collaboration, the field is poised for renewed progress in the treatment of CNS cancers.

Design and Synthesis of SERS Materials for In Vivo Molecular Imaging and Biosensing

Surface-enhanced Raman scattering (SERS) is a feasible and ultra-sensitive method for biomedical imaging and disease diagnosis. SERS is widely applied to in vivo imaging due to the development of functional nanoparticles encoded by Raman active molecules (SERS nanoprobes) and improvements in instruments. Herein, the recent developments in SERS active materials and their in vivo imaging and biosensing applications are overviewed. Various SERS substrates that have been successfully used for in vivo imaging are described. Then, the applications of SERS imaging in cancer detection and in vivo intraoperative guidance are summarized. The role of highly sensitive SERS biosensors in guiding the detection and prevention of diseases is discussed in detail. Moreover, its role in the identification and resection of microtumors and as a diagnostic and therapeutic platform is also reviewed. Finally, the progress and challenges associated with SERS active materials, equipment, and clinical translation are described. The present evidence suggests that SERS could be applied in clinical practice in the future.

Raman Spectroscopy on Brain Disorders: Transition from Fundamental Research to Clinical Applications

Brain disorders such as brain tumors and neurodegenerative diseases (NDs) are accompanied by chemical alterations in the tissues. Early diagnosis of these diseases will provide key benefits for patients and opportunities for preventive treatments. To detect these sophisticated diseases, various imaging modalities have been developed such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). However, they provide inadequate molecule-specific information. In comparison, Raman spectroscopy (RS) is an analytical tool that provides rich information about molecular fingerprints. It is also inexpensive and rapid compared to CT, MRI, and PET. While intrinsic RS suffers from low yield, in recent years, through the adoption of Raman enhancement technologies and advanced data analysis approaches, RS has undergone significant advancements in its ability to probe biological tissues, including the brain. This review discusses recent clinical and biomedical applications of RS and related techniques applicable to brain tumors and NDs.

Tumor vascular heterogeneity and the impact of subtumoral nanoemulsion biodistribution

Aim: Investigate the heterogeneous tumor tissue organization and examine how this condition can interfere with the passive delivery of a lipid nanoemulsion in two breast cancer preclinical models (4T1 and Ehrlich). Materials & methods: The authors used in vivo image techniques to follow the nanoemulsion biodistribution and microtomography, as well as traditional histopathology and electron microscopy to evaluate the tumor structural characteristics. Results & conclusion: Lipid nanoemulsion was delivered to the tumor, vascular organization depends upon the subtumoral localization and this heterogeneous organization promotes a nanoemulsion biodistribution to the highly vascular peripherical region. Also, the results are presented with a comprehensive mathematical model, describing the differential biodistribution in two different breast cancer models, the 4T1 and Ehrlich models.

Advancements in drug delivery methods for the treatment of brain disease

The blood-brain barrier (BBB) presents a formidable obstacle to the effective delivery of systemically administered pharmacological agents to the brain, with ~5% of candidate drugs capable of effectively penetrating the BBB. A variety of biomaterials and therapeutic delivery devices have recently been developed that facilitate drug delivery to the brain. These technologies have addressed many of the limitations imposed by the BBB by: (1) designing or modifying the physiochemical properties of therapeutic compounds to allow for transport across the BBB; (2) bypassing the BBB by administration of drugs via alternative routes; and (3) transiently disrupting the BBB (BBBD) using biophysical therapies. Here we specifically review colloidal drug carrier delivery systems, intranasal, intrathecal, and direct interstitial drug delivery methods, focused ultrasound BBBD, and pulsed electrical field induced BBBD, as well as the key features of BBB structure and function that are the mechanistic targets of these approaches. Each of these drug delivery technologies are illustrated in the context of their potential clinical applications and limitations in companion animals with naturally occurring intracranial diseases.

Remotely controlled near-infrared-triggered photothermal treatment of brain tumours in freely behaving mice using gold nanostars

Current clinical brain tumour therapy practices are based on tumour resection and post-operative chemotherapy or X-ray radiation. Resection requires technically challenging open-skull surgeries that can lead to major neurological deficits and, in some cases, death. Treatments with X-ray and chemotherapy, on the other hand, cause major side-effects such as damage to surrounding normal brain tissues and other organs. Here we report the development of an integrated nanomedicine-bioelectronics brain-machine interface that enables continuous and on-demand treatment of brain tumours, without open-skull surgery and toxicological side-effects on other organs. Near-infrared surface plasmon characteristics of our gold nanostars enabled the precise treatment of deep brain tumours in freely behaving mice. Moreover, the nanostars' surface coating enabled their selective diffusion in tumour tissues after intratumoral administration, leading to the exclusive heating of tumours for treatment. This versatile remotely controlled and wireless method allows the adjustment of nanoparticles' photothermal strength, as well as power and wavelength of the therapeutic light, to target tumours in different anatomical locations within the brain.

Extracellular vesicles for improved tumor accumulation and penetration

Extracellular vesicles (EVs), including microparticles and exosomes, have emerged as potential tools for tumor targeting delivery during the past years. Recently, mass of strategies are applied to assist EVs to accumulate and penetrate into deep tumor sites. In this review, EVs from different cells with unique innate characters and engineered approaches (e.g. chemical engineering, genetical engineering and biomimetic engineering) as drug delivery systems to enhance tumor accumulation and penetration are summarized. Meanwhile, efficient biological function modulation (e.g. extracellular matrix degradation, mechanical property regulation and transcytosis) is introduced to facilitate tumor accumulation and penetration of EVs. Finally, the prospects and challenges on further clinical applications of EVs are discussed.

Intraoperative imaging in pathology-assisted surgery

The pathological assessment of surgical specimens during surgery can reduce the incidence of positive resection margins, which otherwise can result in additional surgeries or aggressive therapeutic regimens. To improve patient outcomes, intraoperative spectroscopic, fluorescence-based, structural, optoacoustic and radiological imaging techniques are being tested on freshly excised tissue. The specific clinical setting and tumour type largely determine whether endogenous or exogenous contrast is to be detected and whether the tumour specificity of the detected biomarker, image resolution, image-acquisition times or penetration depth are to be prioritized. In this Perspective, we describe current clinical standards for intraoperative tissue analysis and discuss how intraoperative imaging is being implemented. We also discuss potential implementations of intraoperative pathology-assisted surgery for clinical decision-making.

Targeted Delivery of DNA Topoisomerase Inhibitor SN38 to Intracranial Tumors of Glioblastoma Using Sub-5 Ultrafine Iron Oxide Nanoparticles

Effectively delivering therapeutics for treating brain tumors is hindered by the physical and biological barriers in the brain. Even with the compromised blood-brain barrier and highly angiogenic blood-tumor barrier seen in glioblastoma (GBM), most drugs, including nanomaterial-based formulations, hardly reach intracranial tumors. This work investigates sub-5 nm ultrafine iron oxide nanoparticles (uIONP) with 3.5 nm core diameter as a carrier for delivering DNA topoisomerase inhibitor 7-ethyl-10-hydroxyl camptothecin (SN38) to treat GBM. Given a higher surface-to-volume ratio, uIONP shows one- or three-folds higher SN38 loading efficiency (48.3 ± 6.1%, mg/mg Fe) than those with core sizes of 10 or 20 nm. SN38 encapsulated in the coating polymer exhibits pH sensitive release with <10% over 48 h at pH 7.4, but 86% at pH 5, thus being protected from converting to inactive glucuronide by UDP-glucuronosyltransferase 1A1. Conjugating α_v β₃ -integrin-targeted cyclo(Arg-Gly-Asp-D-Phe-Cys) (RGD) as ligands, RGD-uIONP/SN38 demonstrates targeted cytotoxicity to α_v β₃ -integrin-overexpressed U87MG GBM cells with a half-maximal inhibitory concentration (IC₅₀ ) of 30.9 ± 2.2 nm. The efficacy study using an orthotopic mouse model of GBM reveals tumor-specific delivery of 11.5% injected RGD-uIONP/SN38 (10 mg Fe kg^-1 ), significantly prolonging the survival in mice by 41%, comparing to those treated with SN38 alone (p < 0.001).

Nanomedicine for brain cancer

CNS tumors remain among the deadliest forms of cancer, resisting conventional and new treatment approaches, with mortality rates staying practically unchanged over the past 30 years. One of the primary hurdles for treating these cancers is delivering drugs to the brain tumor site in therapeutic concentration, evading the blood-brain (tumor) barrier (BBB/BBTB). Supramolecular nanomedicines (NMs) are increasingly demonstrating noteworthy prospects for addressing these challenges utilizing their unique characteristics, such as improving the bioavailability of the payloadsviacontrolled pharmacokinetics and pharmacodynamics, BBB/BBTB crossing functions, superior distribution in the brain tumor site, and tumor-specific drug activation profiles. Here, we review NM-based brain tumor targeting approaches to demonstrate their applicability and translation potential from different perspectives. To this end, we provide a general overview of brain tumor and their treatments, the incidence of the BBB and BBTB, and their role on NM targeting, as well as the potential of NMs for promoting superior therapeutic effects. Additionally, we discuss critical issues of NMs and their clinical trials, aiming to bolster the potential clinical applications of NMs in treating these life-threatening diseases.

Liposomal-Based Formulations: A Path from Basic Research to Temozolomide Delivery Inside Glioblastoma Tissue

Glioblastoma (GBM) is a lethal brain cancer with a very difficult therapeutic approach and ultimately frustrating results. Currently, therapeutic success is mainly limited by the high degree of genetic and phenotypic heterogeneity, the blood brain barrier (BBB), as well as increased drug resistance. Temozolomide (TMZ), a monofunctional alkylating agent, is the first line chemotherapeutic drug for GBM treatment. Yet, the therapeutic efficacy of TMZ suffers from its inability to cross the BBB and very short half-life (~2 h), which requires high doses of this drug for a proper therapeutic effect. Encapsulation in a (nano)carrier is a promising strategy to effectively improve the therapeutic effect of TMZ against GBM. Although research on liposomes as carriers for therapeutic agents is still at an early stage, their integration in GBM treatment has a great potential to advance understanding and treating this disease. In this review, we provide a critical discussion on the preparation methods and physico-chemical properties of liposomes, with a particular emphasis on TMZ-liposomal formulations targeting GBM developed within the last decade. Furthermore, an overview on liposome-based formulations applied to translational oncology and clinical trials formulations in GBM treatment is provided. We emphasize that despite many years of intense research, more careful investigations are still needed to solve the main issues related to the manufacture of reproducible liposomal TMZ formulations for guaranteed translation to the market.

In vivo micro computed tomography detection and decrease in amyloid load by using multifunctionalized gold nanorods: a neurotheranostic platform for Alzheimer's disease

The development and use of nanosystems is an emerging strategy for the diagnosis and treatment of a broad number of diseases, such as Alzheimer's disease (AD). Here, we developed a neurotheranostic nanosystem based on gold nanorods (GNRs) that works as a therapeutic peptide delivery system and can be detected in vivo for microcomputed tomography (micro-CT), being a diagnostic tool. GNRs functionalized with the peptides Ang2 (a shuttle to the Central Nervous System) and D1 (that binds to the Aβ peptide, also inhibiting its aggregation) allowed detecting differences in vivo between wild type and AD mice (APPswe/PSEN1dE9) 15 minutes after a single dose by micro-CT. Moreover, after a recurrent treatment for one month with GNRs-D1/Ang2, we observed a diminution of amyloid load and inflammatory markers in the brain. Thus, this new designed nanosystem exhibits promising properties for neurotheranostics of AD.

Translational oncotargets for immunotherapy: From pet dogs to humans

Preclinical studies in rodent models have been a pivotal role in human clinical research, but many of them fail in the translational process. Spontaneous tumors in pet dogs have the potential to bridge the gap between preclinical models and human clinical trials. Their natural occurrence in an immunocompetent system overcome the limitations of preclinical rodent models. Due to its reasonable cellular, molecular, and genetic homology to humans, the pet dog represents a valuable model to accelerate the translation of preclinical studies to clinical trials in humans, actually with benefits for both species. Moreover, their unique genetic features of breeding and breed-related mutations have contributed to assess and optimize therapeutics in individuals with different genetic backgrounds. This review aims to outline four main immunotherapy approaches - cancer vaccines, adaptive T-cell transfer, antibodies, and cytokines -, under research in veterinary medicine and how they can serve the clinical application crosstalk with humans.

Adsorption of bovine serum albumin on gold nanoprisms: interaction and effect of NIR irradiation on protein corona

Because of their photothermal properties, gold nanoparticles (AuNPs) have gained attention regarding their use in drug delivery and therapeutic applications. In this sense, it is interesting to consider their interactions with biologically available proteins, such as serum albumin, as well as the effects of irradiation and photothermal conversion on the protein structure that can lead to a loss of function or generate an immune response. Gold nanoprisms (AuNPrs) have gained interest due to their low toxicity, ease of synthesis, and excellent stability, promoting their use in bioapplications such as surface-enhanced Raman spectroscopy (SERS), drug delivery, and photothermal therapy. The interaction between AuNPrs, with plasmon bands centred in the near-infrared region (NIR), and bovine serum albumin (BSA) has not been explored yet. UV-Vis spectroscopy, dynamic light scattering (DLS) and fluorescence spectroscopy were used to study the interaction between AuNPrs and BSA in addition to estimation of the adsorption rate and kinetic and thermodynamic parameters (K, ΔH°, ΔG°, ΔS°, and Ea) using adsorption isotherms and Langmuir and Freundlich models. The results suggest spontaneous cooperative binding in multilayer adsorption, achieved by the chemisorption of BSA on the AuNPr surface through the S-Au interaction, as confirmed by Raman spectroscopy. On the other hand, the photothermal conversion efficiency (PE) of the coated nanoparticles after NIR irradiation was assessed, resulting in a slight decrease in the PE of BSA coated on AuNPrs in comparison with that of noncapped nanoparticles. The effect of the irradiation on the protein conformation of capped nanoparticles was also assessed; circular dichroism showed BSA unfolding upon interaction with AuNPrs, with a decrease in the α-helix and β-sheet contents, as well as an increase in random coil conformations. Changes in the Raman spectrum suggest a modification of the disposition of the protein residues exposed to the gold surface after NIR irradiation; but at the secondary structure level, no relevant changes were observed. This provides possibilities for the use of NPs-BSA for bioapplications based on the photothermal effect promoted by laser irradiation, since the biological identity of the protein is preserved after NIR irradiation.

Exploring valence states of abnormal mineral deposits in biological tissues using correlative microscopy and spectroscopy techniques: A case study on ferritin and iron deposits from Alzheimer's disease patients

Abnormal accumulation of inorganic trace elements in a human brain, such as iron, zinc and aluminum, oftentimes manifested as deposits and accompanied by a chemical valence change, is pathologically relevant to various neurodegenerative diseases. In particular, Fe²⁺ has been hypothesized to produce free radicals that induce oxidative damage and eventually cause Alzheimer's disease (AD). However, traditional biomedical techniques, e.g. histology staining, are limited in studying the chemical composition and valence states of these inorganic deposits. We apply commonly used physical (phys-) science methods such as X-ray energy dispersive spectroscopy (EDS), focused-ion beam (FIB) and electron energy loss spectroscopy (EELS) in transmission electron microscopy in conjunction with magnetic resonance imaging (MRI), histology and optical microscopy (OM) to study the valence states of iron deposits in AD patients. Ferrous ions are found in all deposits in brain tissues from three AD patients, constituting 0.22-0.50 of the whole iron content in each specimen. Such phys-techniques are rarely used in medical science and have great potential to provide unique insight into biomedical problems.

Ultrahigh Penetration and Retention of Graphene Quantum Dot Mesoporous Silica Nanohybrids for Image Guided Tumor Regression

So far, near-infrared (NIR) light responsive nanostructures have been well-defined in cancer nanomedicine. However, poor penetration and retention in tumors are the limiting factors. Here, we report the ultrahigh penetration and retention of carbanosilica (graphene quantum dots, GQDs embedded mesoporous silica) in solid tumors. After NIR light exposure, quick (0.5 h) emission from the tumor area is observed that is further retained up to a week (tested up to 10 days) with a single dose administration of nanohybrids. Emissive and photothermally active GQDs and porous silica shell (about 31% drug loading) make carbanosilica a promising nanotheranostic agent exhibiting 68.75% tumor shrinking compared to without NIR light exposure (34.48%). Generated heat (∼52 °C) alters the permeability of tumor enhancing the accumulation of nanotheranostics into the tumor environment. Successive tumor imaging ensures the prolonged follow-up of image guided tumor regression due to synergistic therapeutic effect of nanohybrids.

Targeted brain tumor imaging by using discrete biopolymer-coated nanodiamonds across the blood-brain barrier

Short circulation lifetime, poor blood-brain barrier (BBB) permeability and low targeting specificity limit nanovehicles from crossing the vascular barrier and reaching the tumor site. Consequently, the precise diagnosis of malignant brain tumors remains a great challenge. This study demonstrates the imaging of photostable biopolymer-coated nanodiamonds (NDs) with tumor targeting properties inside the brain. NDs are labeled with PEGylated denatured bovine serum albumin (BSA) and tumor vasculature targeting tripeptides RGD. The modified NDs show high colloidal stability in different buffer systems. Moreover, it is found that discrete dcBSA-PEG-NDs cross the in vitro BBB model more effectively than aggregated NDs. Importantly, compared with the non-targeting NDs, RGD-dcBSA-PEG-NDs can selectively target the tumor site in U-87 MG bearing mice after systemic injection. Overall, this discrete ND system enables efficacious brain tumor visualization with minimal toxicity to other major organs, and is worthy of further investigation into the applications as a unique platform for noninvasive theragnostics and/or thermometry at different stages of human diseases in the brain.

Comparative electron and photon excitation of localized surface plasmon resonance in lithographic gold arrays for enhanced Raman scattering

The ability to tune the localized surface plasmon resonance (LSPR) of nanostructures is desirable for surface enhanced Raman spectroscopy (SERS), plasmon-assisted chemistry and other nanophotonic applications. Although historically the LSPR is mainly studied by optical techniques, with the recent advancement in electron monochromators and correctors, it has attracted considerable attention in transmission electron microscopy (TEM). Here, we use electron energy loss spectroscopy (EELS) in a scanning TEM to study individual gold nanodiscs and bowties in lithographic arrays with variable LSPRs by adjusting the size, interspacing, shape and dielectric environment during the nanofabrication process. We observe the strongest Raman signal enhancement when the LSPR frequency is close to the incident laser frequency in Raman spectroscopy. A simplified harmonic oscillator model is used to estimate SERS enhancement factor (EF) from EELS, bridging the connection between electron and photon excitation of plasmonic arrays. This work demonstrates that STEM-EELS shows promise for revealing the contributions of specific LSPR modes to SERS EF. Our results provide guidelines to fine-tune nanoparticle parameters to deliver the maximum signal enhancement in biosensing applications, such as early cancer detection.

Citric acid coated ultrasmall superparamagnetic iron oxide nanoparticles conjugated with lactoferrin for targeted negative MR imaging of glioma

The proposed study was to develop the preparation of ultrasmall superparamagnetic iron oxide nanoparticles (USPIONs) modified with citric acid, with surface conjugated with lactoferrin (Lf), which used as a potential targeted contrast agent for magnetic resonance imaging (MRI) of brain glioma. USPIONs were prepared by the thermal decomposition method. The hydrophobic USPIONs were coated with citric acid by the ligand exchange method. Then, Lf was conjugated into the surface of USPIONs. The obtained Lf-USPIONs were analyzed by fourier transform infrared (FTIR) spectroscopy and polyacrylamide gel electrophoresis. The size, size distribution, shape and superparamagnetic property of Lf-USPIONs were investigated with TEM and vibrating sample magnetometer (VSM). Both FTIR and electrophoresis analysis demonstrated the successful conjugation of Lf to the surface of USPIONs. The average size of Lf-USPIONs was about 8.4 ± 0.5 nm, which was determined using the statistics of measured over 100 nanoparticles in the TEM image, with a negative charge of -7.3 ± 0.2 mV. TEM imaging revealed that Lf-USPIONs were good in dispersion and polygonal in morphology. VSM results indicated that Lf-USPIONs were superparamagnetic and the saturated magnetic intensity was about 69.8 emu/g. The Lf-USPIONs also showed good biocompatibility in hemolysis, cytotoxicity, cell migration and blood biochemistry studies. MR imaging results in vitro and in vivo indicated that Lf-USPIONs exhibited good negative contrast enhancement. Taken together, Lf-USPIONs hold great potential for brain gliomas MR imaging as a nanosized targeted contrast agent.

Advances in nanomedicines for diagnosis of central nervous system disorders

In spite of a great improvement in medical health services and an increase in lifespan, we have witnessed a skyrocket increase in the incidence of central nervous system (CNS) disorders including brain tumors, neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease), ischemic stroke, and epilepsy, which have seriously undermined the quality of life and substantially increased economic and societal burdens. Development of diagnostic methods for CNS disorders is still in the early stage, and the clinical outcomes suggest these methods are not ready for the challenges associated with diagnosis of CNS disorders, such as early detection, specific binding, sharp contrast, and continuous monitoring of therapeutic interventions. Another challenge is to overcome various barrier structures during delivery of diagnostic agents, especially the blood-brain barrier (BBB). Fortunately, utilization of nanomaterials has been pursued as a potential and promising strategy to address these challenges. This review will discuss anatomical and functional structures of BBB and transport mechanisms of nanomaterials across the BBB, and special emphases will be placed on the state-of-the-art advances in the development of nanomedicines from a variety of nanomaterials for diagnosis of CNS disorders. Meanwhile, current challenges and future perspectives in this field are also highlighted.

Controlled Drug Delivery Vehicles in Veterinary Oncology: State-of-the-Art and Future Directions

Controlled drug delivery systems can be used to carry several anticancer agents, including classical chemotherapeutic agents such as doxorubicin, paclitaxel or cisplatin, and are also used for the encapsulation of tyrosine kinase inhibitors and monoclonal antibodies. Usually, the controlled systems are used to decrease drug toxicity, increase local drug concentration or target specific organs or systems. In dogs, liposomal doxorubicin is the most known controlled drug delivery vehicle in veterinary medicine. However, several antitumor drugs can be encapsulated within these systems. Since the delivery vehicles are a relatively new topic in veterinary oncology, this review aims to discuss the current knowledge regarding the controlled drug delivery vehicles and discuss the current challenges and future direction of its use in veterinary oncology.

Whole genome sequencing for mutation discovery in a single case of lysosomal storage disease (MPS type 1) in the dog

Mucopolysaccharidosis (MPS) is a metabolic storage disorder caused by the deficiency of any lysosomal enzyme required for the breakdown of glycosaminoglycans. A 15-month-old Boston Terrier presented with clinical signs consistent with lysosomal storage disease including corneal opacities, multifocal central nervous system disease and progressively worsening clinical course. Diagnosis was confirmed at necropsy based on histopathologic evaluation of multiple organs demonstrating accumulation of mucopolysaccharides. Whole genome sequencing was used to uncover a frame-shift insertion affecting the alpha-L-iduronidase (IDUA) gene (c.19_20insCGGCCCCC), a mutation confirmed in another Boston Terrier presented 2 years later with a similar clinical picture. Both dogs were homozygous for the IDUA mutation and shared coat colors not recognized as normal for the breed by the American Kennel Club. In contrast, the mutation was not detected in 120 unrelated Boston Terriers as well as 202 dogs from other breeds. Recent inbreeding to select for recessive and unusual coat colors may have concentrated this relatively rare allele in the breed. The identification of the variant enables ante-mortem diagnosis of similar cases and selective breeding to avoid the spread of this disease in the breed. Boston Terriers carrying this variant represent a promising model for MPS I with neurological abnormalities in humans.

Dual Imaging Gold Nanoplatforms for Targeted Radiotheranostics

Gold nanoparticles (AuNPs) are interesting for the design of new cancer theranostic tools, mainly due to their biocompatibility, easy molecular vectorization, and good biological half-life. Herein, we report a gold nanoparticle platform as a bimodal imaging probe, capable of coordinating Gd³⁺ for Magnetic Resonance Imaging (MRI) and ⁶⁷Ga³⁺ for Single Photon Emission Computed Tomography (SPECT) imaging. Our AuNPs carry a bombesin analogue with affinity towards the gastrin releasing peptide receptor (GRPr), overexpressed in a variety of human cancer cells, namely PC3 prostate cancer cells. The potential of these multimodal imaging nanoconstructs was thoroughly investigated by the assessment of their magnetic properties, in vitro cellular uptake, biodistribution, and radiosensitisation assays. The relaxometric properties predict a potential T₁- and T₂- MRI application. The promising in vitro cellular uptake of ⁶⁷Ga/Gd-based bombesin containing particles was confirmed through biodistribution studies in tumor bearing mice, indicating their integrity and ability to target the GRPr. Radiosensitization studies revealed the therapeutic potential of the nanoparticles. Moreover, the DOTA chelating unit moiety versatility gives a high theranostic potential through the coordination of other therapeutically interesting radiometals. Altogether, our nanoparticles are interesting nanomaterial for theranostic application and as bimodal T₁- and T₂- MRI / SPECT imaging probes.

From single cells to complex tissues in applications of surface-enhanced Raman scattering

This tutorial review explores how three of the most common methods for introducing nanoparticles to single cells for surface-enhanced Raman scattering measurements can be adapted for experiments with complex tissues.

Issues affecting nanomedicines on the way from the bench to the market

The development of innovative nanomedicine has raised the standards over the last few decades.

Nanocarrier-based drug combination therapy for glioblastoma

The current achievements in treating glioblastoma (GBM) patients are not sufficient because many challenges exist, such as tumor heterogeneity, the blood brain barrier, glioma stem cells, drug efflux pumps and DNA damage repair mechanisms. Drug combination therapies have shown increasing benefits against those challenges. With the help of nanocarriers, enhancement of the efficacy and safety could be gained using synergistic combinations of different therapeutic agents. In this review, we will discuss the major issues for GBM treatment, the rationales of drug combinations with or without nanocarriers and the principle of enhanced permeability and retention effect involved in nanomedicine-based tumor targeting and promising nanodiagnostics or -therapeutics. We will also summarize the recent progress and discuss the clinical perspectives of nanocarrier-based combination therapies. The goal of this article was to provide better understanding and key considerations to develop new nanomedicine combinations and nanotheranostics options to fight against GBM.

Experimental investigation of parameters influencing plasmonic nanoparticle-mediated bubble generation with nanosecond laser pulses

Plasmonic nanoparticles (PNPs) continue to see increasing use in biophotonics for a variety of applications, including cancer detection and treatment. Several PNP-based approaches involve the generation of highly transient nanobubbles due to pulsed laser-induced vaporization and cavitation. While much effort has been devoted to elucidating the mechanisms behind bubble generation with spherical gold nano particles, the effects of particle shape on bubble generation thresholds are not well understood, especially in the nanosecond pulse regime. Our study aims to compare the bubble generation thresholds of gold nanospheres, gold nanorods, and silica-core gold nanoshells with different sizes, resonances, and surface coatings. Bubble generation is detected using a multimodality microscopy platform for simultaneous, nanosecond resolution pump-probe imaging, integrated scattering response, and acoustic transient detection. Nanoshells and large (40-nm width) nanorods were found to have the lowest thresholds for bubble generation, and in some cases they generated bubbles at radiant exposures below standard laser safety limits for skin exposure. This has important implications for both safety and performance of techniques employing pulsed lasers and PNPs.

Surface-Enhanced Raman Scattering Tags for Three-Dimensional Bioimaging and Biomarker Detection

We have recently witnessed a major improvement in the quality of nanoparticles encoded with Raman-active molecules (SERS tags). Such progress relied mainly on a major improvement of fabrication methods for building-blocks, resulting in widespread application of this powerful tool in various fields, with the potential to replace commonly used techniques, such as those based on fluorescence. We present hereby a brief Perspective on surface enhanced Raman scattering (SERS) tags, regarding their composition, morphology, and structure, and describe our own selection from the current state-of-the-art. We then focus on the main bioimaging applications of SERS tags, showing a gradual evolution from two-dimensional studies to three-dimensional analysis. Recent improvements in sensitivity and multiplexing ability have enabled great advancements toward in vivo applications, e.g., highlighting tumor boundaries to guide surgery. In addition, the high level of biomolecule sensitivity reached by SERS tags promises an expansion toward biomarker detection in cases for which traditional methods offer limited reliability, as a consequence of the frequently low analyte concentrations.