Targeted micelles with chemotherapeutics and gene drugs to inhibit the G1/S and G2/M mitotic cycle of prostate cancer

BACKGROUND

Chemotherapy and gene therapy are used in clinical practice for the treatment of castration-resistant prostate cancer. However, the poor efficiency of drug delivery and serious systemic side effects remain an obstacle to wider application of these drugs. Herein, we report newly designed PEO-PCL micelles that were self-assembled and modified by spermine ligand, DCL ligand and TAT peptide to carry docetaxel and anti-nucleostemin siRNA.

RESULTS

The particle size of the micelles was 42 nm, the zeta potential increased from - 12.8 to 15 mV after grafting with spermine, and the optimal N/P ratio was 25:1. Cellular MTT experiments suggested that introduction of the DCL ligand resulted in high toxicity toward PSMA-positive cells and that the TAT peptide enhanced the effect. The expression of nucleostemin was significantly suppressed in vitro and in vivo, and the tumour-inhibition experiment showed that the dual-drug delivery system suppressed CRPC tumour proliferation.

CONCLUSIONS

This targeted drug delivery system inhibited the G1/S and G2/M mitotic cycle via synergistic interaction of chemotherapeutics and gene drugs.

Ethidium bromide-bridged mesoporous silica hybrid nanocarriers for fluorescence cell imaging and drug delivery applications

We report the fabrication of mesoporous organosilica hybrid nanocarriers with red-fluorescence behaviour under UV-light for pH-responsive drug delivery and red-fluorescence-based bioimaging applications in cancer therapy.

Visible-to-NIR-Light Activated Release: From Small Molecules to Nanomaterials

Photoactivatable (alternatively, photoremovable, photoreleasable, or photocleavable) protecting groups (PPGs), also known as caged or photocaged compounds, are used to enable non-invasive spatiotemporal photochemical control over the release of species of interest. Recent years have seen the development of PPGs activatable by biologically and chemically benign visible and near-infrared (NIR) light. These long-wavelength-absorbing moieties expand the applicability of this powerful method and its accessibility to non-specialist users. This review comprehensively covers organic and transition metal-containing photoactivatable compounds (complexes) that absorb in the visible- and NIR-range to release various leaving groups and gasotransmitters (carbon monoxide, nitric oxide, and hydrogen sulfide). The text also covers visible- and NIR-light-induced photosensitized release using molecular sensitizers, quantum dots, and upconversion and second-harmonic nanoparticles, as well as release via photodynamic (photooxygenation by singlet oxygen) and photothermal effects. Release from photoactivatable polymers, micelles, vesicles, and photoswitches, along with the related emerging field of photopharmacology, is discussed at the end of the review.

Comparative study of two poly(amino acid)-based photosensitizer-delivery systems for photodynamic therapy

The photosensitizers (PS) play a vital role in photodynamic therapy (PDT), but the clinical therapeutic effect is limited by its low solubility, easy aggregation and lack of selective tumor uptake. Hence, some biocompatible materials such as poly(amino acid) have been chosen to deliver PS to solve these problems. In this study, we fabricated two kind of poly(amino acid)-based PS delivery systems by using poly (_L-glutamic acid) (PLG) as the backbone material to physically encapsulate (P(T)) and chemically conjugate PS (PT), respectively. Moreover, the anticancer effect of these two PS delivery systems had been comparatively investigated. In vitro experiments verified that the delivery system of PT exhibited more effective treatment effect than that of P(T) because PS was chemically conjugated with PLG in PT which could obviously avoid the π-π stacking effect of PS and induced the aggregation. The less aggregation avoiding the quenching effect could result in an enhanced generation ability of reactive oxygen species to improve PDT treatment effect. Contrarily, the treatment effect of P(T) was lower due to the rigid structure and hydrophobic π-π stacking effect, in which the physically encapsulated PS was easier to aggregate and quench. Hence, the way how to combine carrier with drug is significant for satisfied treatment effect.

Four-Channel Photothermal Plate Reader for High-Throughput Nanoparticle-Amplified Immunoassay

We enhanced the sample throughput of microplate-based photothermal detection by using a semicylindrical prism to expand a point laser source to a long beam for illuminating multiple wells. Coupled with four epoxy-coated thermocouples in alignment with wells on a 96-well microplate, four parallel immunoassays of C-reaction protein (CRP) with antibody-conjugated gold nanoparticles can be simultaneously performed. The sample throughput is further increased by mounting the Styrofoam-enclosed microplate onto a translational/elevator stage so that immunoassays and thermocouple rinse/drying cycles can be implemented in a programmed fashion. The automated assay with three rinse/drying cycles takes only 34.5 min for four samples or 8.62 min/sample, whereas the manual mode with a single thermocouple and a point light source requires at least 66 min for just one sample. With careful calibration of the energy distribution of the expanded laser beam and controllable immersion of the thermocouples, excellent well-to-well (RSD = 1.3%) and cycle-to-cycle (RSD = 4.0%) reproducibility can be attained. The temperature changes can be correlated with the CRP concentration by the Langmuir isotherm, and the low limit of detection, 0.52 ng/mL or 4.33 pM, is well below the plasma CRP levels of both healthy people (<5 μg/mL) and patients (10-500 μg/mL). The serum CRP concentrations quantified by our plate reader are in excellent agreement with the immunoturbidimetric results, demonstrating that this cost-effective, robust, and high-throughput mode for microplate-based immunoassays is amenable to detecting biomarkers in many clinical samples.

Designing Metallogelators Derived from NSAID-based Zn(II) Coordination Complexes for Drug-Delivery Applications

A crystal engineering approach has been invoked to design a new series of eight Zn(II) coordination complexes derived from various non-steroidal anti-inflammatory drugs (NSAIDs), namely diclofenac (DIC), ibuprofen (IBU), naproxen (NAP), flufenamic acid (FLU) and meclofenamic acid (MEC), and two co-ligands, namely N-phenyl-3-pyridylamide (3-Py) and N-phenyl-4-pyridylamide (4-Py), and Zn(NO₃ )₂ as potential supramolecular gelators. Half of the coordination complexes thus synthesized were able to form aqueous gels (MG-3-PyMEC, MG-3-PyDIC, MG-4-PyNAP and MG-4-PyMEC). Single-crystal structures of all eight complexes revealed that they possessed a gelation-inducing 1D hydrogen-bonded network including amide…amide synthon in some cases, which supported strongly the design principles based on which these complexes were synthesized. Interestingly, one such metallogelator complex, namely 3-PyMEC, showed an intriguing anticancer property against a human breast cancer cell line (MDA-MB-231), as revealed by both MTT and cell migration assays.

Metal-Organic Framework (MOF)-Based Drug Delivery

Background:

Developing a controllable drug delivery system is imperative and important to reduce side effects and enhance the therapeutic efficacy of drugs. Metal-organic frameworks (MOFs) an emerging class of hybrid porous materials built from metal ions or clusters bridged by organic linkers have attracted increasing attention in the recent years owing to the unique physical structures possessed, and the potential for vast applications. The superior properties of MOFs, such as well-defined pore aperture, tailorable composition and structure, tunable size, versatile functionality, high agent loading, and improved biocompatibility, have made them promising candidates as drug delivery hosts. MOFs for drug delivery is of great interest and many very promising results have been found, indicating that these porous solids exhibit several advantages over existing systems.

Objective:

This review highlights the latest advances in the synthesis, functionalization, and applications of MOFs in drug delivery, and has classified them using drug loading strategies. Finally, challenges and future perspectives in this research area are also outlined.

Nanoplatform-based cascade engineering for cancer therapy

Various therapeutic techniques have been studied for treating cancer precisely and effectively, such as targeted drug delivery, phototherapy, tumor-specific catalytic therapy, and synergistic therapy, which, however, evoke numerous challenges due to the inherent limitations of these therapeutic modalities and intricate biological circumstances as well. With the remarkable advances of nanotechnology, nanoplatform-based cascade engineering, as an efficient and booming strategy, has been tactfully introduced to optimize these cancer therapies. Based on the designed nanoplatforms, pre-supposed cascade processes could be triggered under specific conditions to generate/deliver more therapeutic species or produce stronger tumoricidal effects inside tumors, aiming to achieve cancer therapy with increased anti-tumor efficacy and diminished side effects. In this review, the recent advances in nanoplatform-based cascade engineering for cancer therapy are summarized and discussed, with an emphasis on the design of smart nanoplatforms with unique structures, compositions and properties, and the implementation of specific cascade processes by means of endogenous tumor microenvironment (TME) resources and/or exogenous energy inputs. This fascinating strategy presents unprecedented potential in the enhancement of cancer therapies, and offers better controllability, specificity and effectiveness of therapeutic functions compared to the corresponding single components/functions. In the end, challenges and prospects of such a burgeoning strategy in the field of cancer therapy will be discussed, hopefully to facilitate its further development to meet the personalized treatment demands.

A review on nanotoxicity and nanogenotoxicity of different shapes of nanomaterials

Nanomaterials (NMs) generally display fascinating physical and chemical properties that are not always present in bulk materials; therefore, any modification to their size, shape, or coating tends to cause significant changes in their chemical/physical and biological characteristics. The dramatic increase in efforts to use NMs renders the risk assessment of their toxicity highly crucial due to the possible health perils of this relatively uncharted territory. The different sizes and shapes of the nanoparticles are known to have an impact on organisms and an important place in clinical applications. The shape of nanoparticles, namely, whether they are rods, wires, or spheres, is a particularly critical parameter to affect cell uptake and site-specific drug delivery, representing a significant factor in determining the potency and magnitude of the effect. This review, therefore, intends to offer a picture of research into the toxicity of different shapes (nanorods, nanowires, and nanospheres) of NMs to in vitro and in vivo models, presenting an in-depth analysis of health risks associated with exposure to such nanostructures and benefits achieved by using certain model organisms in genotoxicity testing. Nanotoxicity experiments use various models and tests, such as cell cultures, cores, shells, and coating materials. This review article also attempts to raise awareness about practical applications of NMs in different shapes in biology, to evaluate their potential genotoxicity, and to suggest approaches to explain underlying mechanisms of their toxicity and genotoxicity depending on nanoparticle shape.

Fatty Acid Remodeling of Membrane Glycerophospholipids Induced by Bleomycin and Iron Oxide Nanoparticles in Human Embryonic Kidney Cells

Bleomycin has a long-studied mechanism of action through the formation of a complex with metals, such as iron. The bleomycin-iron complex was recently shown to induce membrane damage by free radical reactivity. Because the use of Fe nanoparticles is spreading for drug delivery strategies, molecular mechanisms of cell damage must include different compartments in order to observe the progression of the cell reactivity. In this study, human embryonic kidney (HEK-293) cells were exposed for 24 h to bleomycin and polymeric iron oxide nanoparticles (Fe-NPs), alone or in combination. The fatty acid-based membrane lipidomic analysis evidenced the fatty acid remodeling in response to the treatments. Bleomycin alone caused the increase of saturated fatty acid (SFA) moieties in cell membrane glycerophospholipids with concomitant diminution of monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acid levels. Under Fe-NPs treatment, omega-6 PUFA decreased and trans fatty acid isomers increased. Under coadministration bleomycin and Fe-NPs, all membrane remodeling changes disappeared compared to those of the controls, with only an increase of omega-6 PUFA that elevates peroxidation index remaining. Our results highlight the important role of fatty-acid-based membrane lipidome monitoring to follow up the fatty acid reorganization induced by the drug, to be considered as a side effect of the pharmacological activity, suggesting the need of an integrated approach for the investigation of drug and carrier molecular mechanisms.

Biosensing: The best alternative for conventional methods in detection of Alzheimer's disease biomarkers

Conceivably the imperative reason for the absence of appropriate treatment for Alzheimer's disease (AD) is the late onset of clinical symptoms followed by late treatment. Specific biomarkers play a vital role in this area. The amyloid-beta peptide, tau protein and micRNA, are the most important biomarker associated in AD. There are many routine methods for identifying these biomarkers which molecular based methods with a high accuracy and sensitivity have been considered. These methods have some limitations such as; false positive and negative results, problem on the interpretation, complexity and time-consuming, high cost instruments and etc. To overcome these limitations, bioassays were developed extensively. There exist a multitude of possible applications for Alzheimer's disease biomarkers by using biosensors. This review mainly focuses on major biomarkers in Alzheimer's disease, routine and old methods in identifying biomarkers of AD and their advantages and limitation, and biosensors to the identification of amyloid beta, tau protein and micRNAs biomarkers. Furthermore, evaluation the strengths and weaknesses of the developed bioassays and introduce leading challenges are considered in this review.

Albumin-based nanoparticles as contrast medium for MRI: vascular imaging, tissue and cell interactions, and pharmacokinetics of second-generation nanoparticles

This multidisciplinary study examined the pharmacokinetics of nanoparticles based on albumin-DTPA-gadolinium chelates, testing the hypothesis that these nanoparticles create a stronger vessel signal than conventional gadolinium-based contrast agents and exploring if they are safe for clinical use. Nanoparticles based on human serum albumin, bearing gadolinium and designed for use in magnetic resonance imaging, were used to generate magnet resonance images (MRI) of the vascular system in rats ("blood pool imaging"). At the low nanoparticle doses used for radionuclide imaging, nanoparticle-associated metals were cleared from the blood into the liver during the first 4 h after nanoparticle application. At the higher doses required for MRI, the liver became saturated and kidney and spleen acted as additional sinks for the metals, and accounted for most processing of the nanoparticles. The multiple components of the nanoparticles were cleared independently of one another. Albumin was detected in liver, spleen, and kidneys for up to 2 days after intravenous injection. Gadolinium was retained in the liver, kidneys, and spleen in significant concentrations for much longer. Gadolinium was present as significant fractions of initial dose for longer than 2 weeks after application, and gadolinium clearance was only complete after 6 weeks. Our analysis could not account quantitatively for the full dose of gadolinium that was applied, but numerous organs were found to contain gadolinium in the collagen of their connective tissues. Multiple lines of evidence indicated intracellular processing opening the DTPA chelates and leading to gadolinium long-term storage, in particular inside lysosomes. Turnover of the stored gadolinium was found to occur in soluble form in the kidneys, the liver, and the colon for up to 3 weeks after application. Gadolinium overload poses a significant hazard due to the high toxicity of free gadolinium ions. We discuss the relevance of our findings to gadolinium-deposition diseases.

Morin hydrate loaded solid lipid nanoparticles: Characterization, stability, anticancer activity, and bioavailability

Nanotechnology has come up as a protean field integrating concepts of alternate drug delivery systems using nanocarriers. The idea of encapsulating a drug molecule into a colloidal carrier like solid lipid nanoparticle has been a promising approach for development of nanomedicines. In this research work, a hydrophobic, natural, and an anticancer bioflavonoid, morin hydrate (MH) was encapsulated into solid lipid nanoparticles to overcome the issues of its poor aqueous solubility and low oral bioavailability. The prepared morin hydrate loaded solid lipid nanoparticles (MSN) were characterized by DLS, FTIR, and DSC analysis. The MSN showed nanoscale size, good steric stability, and release in simulated intestinal fluid. The in-vitro anticancer studies against human cervical cancer cells revealed the higher cytotoxicity of encapsulated MH than free or pure MH. MSN also demonstrated a significant improvement in pharmacokinetics of encapsulated MH.

Computational Insights into the Binding of Monolayer-Capped Gold Nanoparticles onto Amyloid-β Fibrils

Amyloids-β (Aβ) fibrils are involved in several neurodegenerative diseases. In this study, atomistic molecular dynamics simulations have been used to investigate how monolayer-protected gold nanoparticles interact with Aβ(1-40) and Aβ(1-42) fibrils. Our results show that small gold nanoparticles bind with the external side of amyloid-β fibrils that is involved in the fibrillation process. The binding affinity, studied for both kinds of fibrils as a function of the monolayer composition and the nanoparticle diameter, is modulated by hydrophobic interactions and ligand monolayer conformation. Our findings thus show that monolayer-protected nanoparticles are good candidates to prevent fibril aggregation and secondary nucleation or to deliver drugs to specific fibril regions.

Recent Advances in Nanomedicine for the Diagnosis and Therapy of Liver Fibrosis

Liver fibrosis, a reversible pathological process of inflammation and fiber deposition caused by chronic liver injury and can cause severe health complications, including liver failure, liver cirrhosis, and liver cancer. Traditional diagnostic methods and drug-based therapy have several limitations, such as lack of precision and inadequate therapeutic efficiency. As a medical application of nanotechnology, nanomedicine exhibits great potential for liver fibrosis diagnosis and therapy. Nanomedicine enhances imaging contrast and improves tissue penetration and cellular internalization; it simultaneously achieves targeted drug delivery, combined therapy, as well as diagnosis and therapy (i.e., theranostics). In this review, recent designs and development efforts of nanomedicine systems for the diagnosis, therapy, and theranostics of liver fibrosis are introduced. Relative to traditional methods, these nanomedicine systems generally demonstrate significant improvement in liver fibrosis treatment. Perspectives and challenges related to these nanomedicine systems translated from laboratory to clinical use are also discussed.

Anticancer Properties of Platinum Nanoparticles and Retinoic Acid: Combination Therapy for the Treatment of Human Neuroblastoma Cancer

Neuroblastoma is the most common extracranial solid tumor in childhood. The different treatments available for neuroblastoma are challenged by high rates of resistance, recurrence, and progression, most notably in advanced cases and highly malignant tumors. Therefore, the development of more targeted therapies, which are biocompatible and without undesired side effects, is highly desirable. The mechanisms of actions of platinum nanoparticles (PtNPs) and retinoic acid (RA) in neuroblastoma have remained unclear. In this study, the anticancer effects of PtNPs and RA on neuroblastoma were assessed. We demonstrated that treatment of SH-SY5Y cells with the combination of PtNPs and RA resulted in improved anticancer effects. The anticancer effects of the two compounds were mediated by cytotoxicity, oxidative stress (OS), mitochondrial dysfunction, endoplasmic reticulum stress (ERS), and apoptosis-associated networks. Cytotoxicity was confirmed by leakage of lactate dehydrogenase (LDH) and intracellular protease, and oxidative stress increased the level of reactive oxygen species (ROS), 4-hydroxynonenal (HNE), malondialdehyde (MDA), and nitric oxide (NO), and protein carbonyl content (PCC). The combination of PtNPs and RA caused mitochondrial dysfunction by decreasing the mitochondrial membrane potential (MMP), adenosine triphosphate (ATP) content, number of mitochondria, and expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). Endoplasmic reticulum-mediated stress and apoptosis were confirmed by upregulation of protein kinase RNA-like endoplasmic reticulum kinase (PERK), inositol-requiring enzyme 1 (IRE1), activating transcription factor 6 (ATF6), activating transcription factor 4 (ATF4), p53, Bax, and caspase-3 and down regulation of B-cell lymphoma 2 (BCl-2). PtNPs and RA induced apoptosis, and oxidative DNA damage was evident by the accumulation of 8-hydroxy-2-deoxyguanosine (8-OHdG) and 8-hydroxyguanosine (8-OHG). Finally, PtNPs and RA increased the differentiation and expression of differentiation markers. Differentiated SH-SY5Y cells pre-treated with PtNPs or RA or the combination of both were more sensitive to the cytotoxic effect of cisplatin than undifferentiated cells. To our knowledge, this is the first study to demonstrate the effect of the combination of PtNPs and RA in neuroblastoma cells. PtNPs may be a potential preconditioning or adjuvant compound in chemotherapeutic treatment. The results of this study provide a rationale for clinical evaluation of the combination of PtNPs and RA for the treatment of children suffering from high-risk neuroblastoma.

Mesoporous Silica Nanoparticles in Bioimaging

A biomedical contrast agent serves to enhance the visualisation of a specific (potentially targeted) physiological region. In recent years, mesoporous silica nanoparticles (MSNs) have developed as a flexible imaging platform of tuneable size/morphology, abundant surface chemistry, biocompatibility and otherwise useful physiochemical properties. This review discusses MSN structural types and synthetic strategies, as well as methods for surface functionalisation. Recent applications in biomedical imaging are then discussed, with a specific emphasis on magnetic resonance and optical modes together with utility in multimodal imaging.

The double life of conductive nanopipette: a nanopore and an electrochemical nanosensor

The continuing interest in nanoscale research has spurred the development of nanosensors for liquid phase measurements. These include nanopore-based sensors typically employed for detecting nanoscale objects, such as nanoparticles, vesicles and biomolecules, and electrochemical nanosensors suitable for identification and quantitative analysis of redox active molecules. In this Perspective, we discuss conductive nanopipettes (CNP) that can combine the advantages of single entity sensitivity of nanopore detection with high selectivity and capacity for quantitative analysis offered by electrochemical sensors. Additionally, the small physical size and needle-like shape of a CNP enables its use as a tip in the scanning electrochemical microscope (SECM), thus, facilitating precise positioning and localized measurements in biological systems.

Polyvinyl Alcohol/Sodium Alginate Hydrogels Incorporated with Silver Nanoclusters via Green Tea Extract for Antibacterial Applications

Silver-based nanoparticles and biomaterials have extensive biomedical applications owing to their unique antimicrobial properties. Thus, green and facile synthesis of such materials is highly desirable. This study reports an antibacterial hydrogel based on polyvinyl alcohol/sodium alginate network with the incorporation of silver nanoparticles (AgNPs), which is greenly synthesized by reductive metabolites obtained from the leaves of green tea. The 'flower-shape' AgNPs were acquired, it formed a mono-disperse system with a distinct uniform interparticle separation. The average size of AgNPs varied from 129.5 to 243.6 nm, which could be regulated by using different volumes of the green tea extract. Zeta potentials of the AgNPs were from -39.3 mV to -20.3 mV, indicating the moderate stability of the particles in water. In the next stage, the antibacterial polyvinyl alcohol/sodium alginate hydrogels were fabricated by incorporating prepared AgNPs. Scanning Electron Microscopy (SEM) images showed that the porous structure was obtained, and Energy Dispersive X-Ray (EDX) analysis confirmed that the AgNPs were uniformly dispersed in the polymer network. The hydrogels exhibited superior water absorption properties, which were characterized by a high swelling ratio (500-900%) and fast equilibrium. The hydrogels also exhibited good antimicrobial activity in assays with Gram-positive bacteria Escherichia coli and Gram-negative bacteria Staphylococcus aureus. To sum up, a process for the green preparation of antibacterial hydrogels based on AgNPs derived from tea leaves as a conveniently available cheap local agricultural product was established.

Anti-Leukemia Activity of Au/CuO/ZnO Nanoparticles Synthesized used Verbena officinalis Extract

As biological synthesis has become an alternative to chemical and physical methods for synthesizing nanoparticles, this work describes the synthesis of Au/CuO/ZnO nanoparticles using Verbena officinalis extract. The synthesized Au/CuO/ZnO nanoparticles were characterized using Ultraviolet–Visible, Fourier Transform-Infrared, Transmission Electron Microscopy and Atomic Force Microscopy. The influence of Au/CuO/ZnO nanoparticles on cell viability was evaluated in vitro, using the established cell line – Jurkat (ATCC® TIB-152™). The Annexin V binding test confirmed the previous results of the MTT assay, which indicate that the studied complex of Au/CuO/ZnO nanoparticles has a strong cytotoxic effect on the Jurkat cell line. The type of death and the effectiveness of cell elimination depended both on the concentration of the complex and the duration of culture.

Acid-sensitive PEGylated paclitaxel prodrug nanoparticles for cancer therapy: Effect of PEG length on antitumor efficacy

Paclitaxel is one of the most widely used anticancer agents, but strong side effects and low bioavailability limit its clinical efficacy. The use of tumor microenvironment-responsive prodrugs is promising to solve these problems, and a smart linkage is crucial to achieve the efficient release of paclitaxel from such prodrugs in tumor. Herein, an acid-responsive acetone-based acyclic ketal linkage is used to construct paclitaxel prodrugs with different length of poly(ethylene glycol) (PEG). The PEGylated acetone-based acyclic-ketal-linked prodrugs of paclitaxel (PKPs) self-assembled into nanoparticles that were stable in normal physiological environment but released paclitaxel rapidly in mildly acidic environment in tumor. The length of PEG had considerable impact on size and critical micelle concentration of PKP nanoparticles, thereby affecting prodrug hydrolysis kinetics, pharmacokinetics, biodistribution, and antitumor activity for PKP nanoparticles. In an A2780 xenograft mouse model, PKP nanoparticles displayed improved pharmacokinetics and superior antitumor efficacy against Taxol. Our results demonstrate that acyclic-ketal-based prodrugs are useful for the development of acid-responsive anticancer nanomedicines.

Engineering Delivery of Nonbiologics Using Poly(lactic-co-glycolic acid) Nanoparticles for Repair of Disrupted Brain Endothelium

Traumatic brain injury (TBI) is known to alter the structure and function of the blood-brain barrier (BBB). Blunt force or explosive blast impacting the brain can cause neurological sequelae through the mechanisms that remain yet to be fully elucidated. For example, shockwaves propagating through the brain have been shown to create a mechanical trauma that may disrupt the BBB. Indeed, using tissue engineering approaches, the shockwave-induced mechanical injury has been shown to modulate the organization and permeability of the endothelium tight junctions. Because an injury to the brain endothelium typically induces a high expression of E-selectin, we postulated that upregulation of this protein after an injury can be exploited for diagnosis and potential therapy through targeted nanodelivery to the injured brain endothelium. To test this hypothesis, we engineered poly(lactic-co-glycolic acid) (PLGA) nanoparticles to encapsulate therapeutic nonbiologics and decorated them with ligands to specifically target the E-selectin. A high level of the conjugated nanoparticles was found inside the injured cells. Repair of the injury site was then quantitatively measured and analyzed. To summarize, exploiting the tunable properties of PLGA, a targeted drug delivery strategy has been developed and validated, which combines the specificity of ligand/receptor interaction with therapeutic reagents. Such a strategy could be used to provide a potential theragnostic approach for the treatment of modulated brain endothelium associated with TBI.

SiO2@Cu7S4 nanotubes for photo/chemodynamic and photo-thermal dual-mode synergistic therapy under 808 nm laser irradiation

Photodynamic therapy (PDT) is a light-based modality for tumor treatment that involves the generation of reactive oxygen species (ROS) by the combination of light, a photosensitizer, and molecular oxygen. Nevertheless, the therapeutic effects of PDT are limited by hypoxic conditions that worsen with oxygen consumption during the PDT process. Photo/chemodynamic therapy (PCDT) based on the Fenton reaction is one strategy to improve ROS generation, provided a highly effective Fenton reagent is developed. In this research, SiO₂@Cu₇S₄ nanotubes (NTs) were synthesized as a PCDT agent. This double-valence metal-sulfide composite material can react with H₂O₂ at the tumor site. SiO₂@Cu₇S₄ NTs can produce more ROS than the traditional PDT agents, and besides, they can also be used as a photothermal therapy (PTT) agent. SiO₂@Cu₇S₄ NTs will trigger the PTT effect under 808 nm irradiation and generate a large amount of heat to eradicate cancer cells. This heat will also promote the PCDT effect by increasing the reaction rate. Thus, the SiO₂@Cu₇S₄ NT is a suitable material for PCDT and PTT synergistic oncotherapy. The 808 nm laser is selected as the appropriate excitation source, providing adequate penetration and minimal harm to normal cells. The experimental data presented herein demonstrate the promising photosensitive, Fenton-like, and photothermal performance of SiO₂@Cu₇S₄ NTs. Furthermore, the findings could promote the development of PCDT and PTT synergistic therapy. Thus, this research provides a feasible method to design a single, multifunctional material for cancer treatment.

Genetically modified Pichia pastoris, a powerful resistant factory for gold and palladium bioleaching and nanostructure heavy metal biosynthesis

A metal-resistant engineered Pichia pastoris was developed here to fulfil the metal bioleaching in aqueous conditions. Parent and recombinant yeasts were grown in YPD medium containing different concentrations of ion metals. XRD, electron microscopy and particle size analyser were used for the characterisation and the nanoparticle analyses. The nanoparticle production kinetics were studied by ICP-OES. The cytotoxicity of nanoparticles was assayed against human cell lines. Media colours changed to a range from purplish-brown to grey during early fermentation stages. The maximum biosorption capacities were recorded 81.23 and 493.35 mg/g for gold and palladium in batch conditions, respectively. Various physical investigations proved monodispersed spherical nanoparticles around 100 nm in size. Pure palladium nanoparticles and PdCl₂ represented the least cytotoxic potency towards T47D and EPG85.257 cells. The results demonstrated that the genetically modified yeast is a cost-effective, high-throughput, robust, and facile system for metal biosorption.

Lipid Chemical Structure Modulates the Disruptive Effects of Nanomaterials on Membrane Models

Understanding the mechanisms by which engineered nanomaterials disrupt the cell plasma membrane is crucial in advancing the industrial and biomedical applications of nanotechnology. While the role of nanoparticle properties in inducing membrane damage has received significant attention, the role of the lipid chemical structure in regulating such interactions is less explored. Here, we investigated the role of the lipid chemical structure in the disruption of lipid vesicles by unmodified silica, carboxyl-modified silica, and unmodified polystyrene nanoparticles (50 nm). The role of the lipid headgroup was examined by comparing nanoparticle effects on vesicles composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) vs an inverse phosphocholine (PC) with the same acyl chain structure. The role of acyl chain saturation was examined by comparing nanoparticle effects on saturated vs unsaturated PCs and sphingomyelins. Nanoparticle effects on PCs (glycerol backbone) vs sphingomyelins (sphingosine backbone) were also examined. Results showed that the lipid headgroup, backbone, and acyl chain saturation affect nanoparticle binding to and disruption of the membranes. A low headgroup tilt angle and the presence of a trimethylammonium moiety at the vesicle surface are required for unmodified nanoparticles to induce membrane disruption. Lipid backbone structure significantly affects nanoparticle-membrane interactions, with carboxyl-modified particles only disrupting lipids containing cis unsaturation and a sphingosine backbone. Acyl chain saturation makes vesicles more resistant to particles by increasing lipid packing in vesicles, impeding molecular interactions. Finally, nanoparticles were capable of changing the lipid packing, resulting in pore formation in the process. These observations are important in interpreting nanoparticle toxicity to biological membranes.

Influence of the Surface Functionalization on the Fate and Performance of Mesoporous Silica Nanoparticles

Mesoporous silica nanoparticles have been broadly applied as drug delivery systems owing to their exquisite features, such as excellent textural properties or biocompatibility. However, there are various biological barriers that prevent their proper translation into the clinic, including: (1) lack of selectivity toward tumor tissues, (2) lack of selectivity for tumoral cells and (3) endosomal sequestration of the particles upon internalization. In addition, their open porous structure may lead to premature drug release, consequently affecting healthy tissues and decreasing the efficacy of the treatment. First, this review will provide a comprehensive and systematic overview of the different approximations that have been implemented into mesoporous silica nanoparticles to overcome each of such biological barriers. Afterward, the potential premature and non-specific drug release from these mesoporous nanocarriers will be addressed by introducing the concept of stimuli-responsive gatekeepers, which endow the particles with on-demand and localized drug delivery.

Identifying the Red-Luminophore-Forming Domain in Serum Albumin-Gold Complexes

Serum albumin-gold complexes exhibit UV-excitable red luminescence (λ_em = 640 nm) with unusual Stokes shifts compared with the innate UV/blue fluorescence arising from the aromatic residues. In order to understand the mechanism of this luminescence, we employed limited proteolysis and molecular cloning techniques and assessed the domain containing the red luminophore in bovine serum albumin (BSA) and human serum albumin (HSA). We identified that the luminophore is localized in a domain of serum albumin, residing within the N-terminus half.

Osteotropic Radiolabeled Nanophotosensitizer for Imaging and Treating Multiple Myeloma

Rapid liver and spleen opsonization of systemically administered nanoparticles (NPs) for in vivo applications remains the Achilles' heel of nanomedicine, allowing only a small fraction of the materials to reach the intended target tissue. Although focusing on diseases that reside in the natural disposal organs for nanoparticles is a viable option, it limits the plurality of lesions that could benefit from nanomedical interventions. Here we designed a theranostic nanoplatform consisting of reactive oxygen (ROS)-generating titanium dioxide (TiO2) NPs, coated with a tumor-targeting agent, transferrin (Tf), and radiolabeled with a radionuclide (89Zr) for targeting bone marrow, imaging the distribution of the NPs, and stimulating ROS generation for cell killing. Radiolabeling of TiO2 NPs with 89Zr afforded thermodynamically and kinetically stable chelate-free 89Zr-TiO2-Tf NPs without altering the NP morphology. Treatment of multiple myeloma (MM) cells, a disease of plasma cells originating in the bone marrow, with 89Zr-TiO2-Tf generated cytotoxic ROS to induce cancer cell killing via the apoptosis pathway. Positron emission tomography/X-ray computed tomography (PET/CT) imaging and tissue biodistribution studies revealed that in vivo administration of 89Zr-TiO2-Tf in mice leveraged the osteotropic effect of 89Zr to selectively localize about 70% of the injected radioactivity in mouse bone tissue. A combination of small-animal PET/CT imaging of NP distribution and bioluminescence imaging of cancer progression showed that a single-dose 89Zr-TiO2-Tf treatment in a disseminated MM mouse model completely inhibited cancer growth at euthanasia of untreated mice and at least doubled the survival of treated mice. Treatment of the mice with cold Zr-TiO2-Tf, 89Zr-oxalate, or 89Zr-Tf had no therapeutic benefit compared to untreated controls. This study reveals an effective radionuclide sensitizing nanophototherapy paradigm for the treatment of MM and possibly other bone-associated malignancies.

Preparation of Peptide and Recombinant Tissue Plasminogen Activator Conjugated Poly(Lactic-Co-Glycolic Acid) (PLGA) Magnetic Nanoparticles for Dual Targeted Thrombolytic Therapy

Recombinant tissue plasminogen activator (rtPA) is the only thrombolytic agent that has been approved by the FDA for treatment of ischemic stroke. However, a high dose intravenous infusion is required to maintain effective drug concentration, owing to the short half-life of the thrombolytic drug, whereas a momentous limitation is the risk of bleeding. We envision a dual targeted strategy for rtPA delivery will be feasible to minimize the required dose of rtPA for treatment. For this purpose, rtPA and fibrin-avid peptide were co-immobilized to poly(lactic-co-glycolic acid) (PLGA) magnetic nanoparticles (PMNP) to prepare peptide/rtPA conjugated PMNPs (pPMNP-rtPA). During preparation, PMNP was first surface modified with avidin, which could interact with biotin. This is followed by binding PMNP-avidin with biotin-PEG-rtPA (or biotin-PEG-peptide), which was prepared beforehand by binding rtPA (or peptide) to biotin-PEG-maleimide while using click chemistry between maleimide and the single -SH group in rtPA (or peptide). The physicochemical property characterization indicated the successful preparation of the magnetic nanoparticles with full retention of rtPA fibrinolysis activity, while biological response studies underlined the high biocompatibility of all magnetic nanoparticles from cytotoxicity and hemolysis assays in vitro. The magnetic guidance and fibrin binding effects were also confirmed, which led to a higher thrombolysis rate in vitro using PMNP-rtPA or pPMNP-rtPA when compared to free rtPA after static or dynamic incubation with blood clots. Using pressure-dependent clot lysis model in a flow system, dual targeted pPMNP-rtPA could reduce the clot lysis time for reperfusion by 40% when compared to free rtPA at the same drug dosage. From in vivo targeted thrombolysis in a rat embolic model, pPMNP-rtPA was used at 20% of free rtPA dosage to restore the iliac blood flow in vascular thrombus that was created by injecting a blood clot to the hind limb area.

A Microfluidic Platform to design Multimodal PEG - crosslinked Hyaluronic Acid Nanoparticles (PEG-cHANPs) for diagnostic applications

The combination of different imaging modalities can allow obtaining simultaneously morphological and functional information providing a more accurate diagnosis. This advancement can be reached through the use of multimodal tracers, and nanotechnology-based solutions allow the simultaneous delivery of different diagnostic compounds moving a step towards their safe administration for multimodal imaging acquisition. Among different processes, nanoprecipitation is a consolidate method for the production of nanoparticles and its implementation in microfluidics can further improve the control over final product features accelerating its potential clinical translation. A Hydrodynamic Flow Focusing (HFF) approach is proposed to produce through a ONE-STEP process Multimodal Pegylated crosslinked Hyaluronic Acid NanoParticles (PEG-cHANPs). A monodisperse population of NPs with an average size of 140 nm is produced and Gd-DTPA and ATTO488 compounds are co-encapsulated, simultaneously. The results showed that the obtained multimodal nanoparticle could work as MRI/Optical imaging probe. Furthermore, under the Hydrodenticity effect, a boosting of the T1 values with respect to free Gd-DTPA is preserved.

Individually cultured bovine embryos produce extracellular vesicles that have the potential to be used as non-invasive embryo quality markers

Extracellular vesicles (EVs) are membrane-bound biological nanoparticles (NPs) and have gained wide attention as potential biomarkers. We aimed to isolate and characterize EVs from media conditioned by individually cultured preimplantation bovine embryos and to assess their relationship with embryo quality. Presumptive zygotes were cultured individually in 60 μl droplets of culture media, and 50 μl of media were collected from the droplets either on day 2, 5 or 8 post-fertilization. After sampling, the embryo cultures were continued in the remaining media until day 8, and the embryo development was evaluated at day 2 (cleavage), day 5 (morula stage) and day 8 (blastocyst stage). EVs were isolated using qEVsingle® columns and characterized. Based on EV Array, EVs isolated from embryo conditioned media were strongly positive for EV-markers CD9 and CD81 and weakly positive for CD63 and Alix among others. They had a cup-like shape typical to EVs as analyzed by transmission electron microscopy and spherical shape in scanning electron microscopy, and hence regarded as EVs. However, the NPs isolated from control media were negative for EV markers. Based on nanoparticle tracking analysis, at day 2, the mean concentration of EVs isolated from media conditioned by embryos that degenerated after cleaving (8.25 × 10⁸/ml) was higher compared to that of embryos that prospectively developed to blastocysts (5.86 × 10⁸/ml, p < 0.05). Moreover, at day 8, the concentration of EVs isolated from media conditioned by degenerating embryos (7.17 × 10⁸/ml) was higher compared to that of blastocysts (5.68 × 10⁸/ml, p < 0.05). Furthermore, at day 8, the mean diameter of EVs isolated from media conditioned by degenerating embryos (153.7 nm) was smaller than EVs from media conditioned by blastocysts (163.5 nm, p < 0.05). In conclusion, individually cultured preimplantation bovine embryos secrete EVs in the culture media and their concentration and size are influenced by embryo quality and may indicate their prospective development potential.

A Multiparametric Evaluation of Quantum Dot Size and Surface-Grafted Peptide Density on Cellular Uptake and Cytotoxicity

Despite the progress in nanotechnology for biomedical applications, great efforts are still being employed in optimizing nanoparticle (NP) design parameters to improve functionality and minimize bionanotoxicity. In this study, we developed CdSe/CdS/ZnS core/shell/shell quantum dots (QDs) that are compact ligand-coated and surface-functionalized with an HIV-1-derived TAT cell-penetrating peptide (CPP) analog to improve both biocompatibility and cellular uptake. Multiparametric studies were performed in different mammalian and murine cell lines to compare the effects of varying QD size and number of surface CPPs on cellular uptake, viability, generation of reactive oxygen species, mitochondrial health, cell area, and autophagy. Our results showed that the number of cell-associated NPs and their respective toxicity are higher for the larger QDs. Meanwhile, increasing the number of surface CPPs also enhanced cellular uptake and induced cytotoxicity through the generation of mitoROS and autophagy. Thus, here we report the optimal size and surface CPP combinations for improved QD cellular uptake.

Augmented interaction of multivalent arginine coated gold nanoclusters with lipid membranes and cells

A library of ultra-small red photoluminescent gold nanoclusters (Au NCs) were synthesized with an increasing amount of positive charges provided by the addition of mono-, di- or trivalent-glutathione modified arginine peptides. We then studied how the arginine content impacted on the interaction of Au NCs with negatively charged artificial lipid bilayers and cell membranes. Results indicated that increasing the arginine content enhanced Au NCs' adsorption on lipid bilayers and on cell membranes followed by an increased cellular uptake in melanoma cells (COLO 829). Surprisingly, the presence of up to 40% serum for highly positively charged Au NCs did not hinder their interaction with lipid bilayers that contain glycolipids, suggesting a reduced opsonization of these Au NCs. In addition, these Au NCs are usually not toxic, except those with the highest arginine contents. Thus, controlled grafting of arginine peptides onto Au NCs is an elegant strategy to improve their binding and internalization by tumor cells while still keeping their anti-fouling properties.

An Atomistic Molecular Dynamics Study of Titanium Dioxide Adhesion to Lipid Bilayers

Titanium dioxide (TiO₂) nanoparticles are found in an array of consumer and industrial products, and human exposure to these nanoparticles involves interaction with biological membranes. To understand the effect of the membrane lipid composition on bilayer perturbation by TiO₂, we performed all-atom molecular dynamics simulations of nanosized TiO₂ interacting with three single component bilayers differing only in their headgroup composition: the zwitterionic DOPC, which is overall neutral containing negatively charged phosphate and positively charged choline in its head, DOPG, which is overall anionic containing negatively charged phosphate and neutral glycerol, and the anionic DOPS, containing negatively charged phosphate attached to the hydroxyl side-chain of the amino acid, serine containing negatively charged carboxyl and positively charged ammonium. The nanoparticle adheres to all three bilayers causing a negative curvature on their top leaflet. However, the local deformation of DOPG was more pronounced than DOPC and DOPS. The anionic DOPG, which is the thinnest of the three bilayers, interacted most strongly with the TiO₂. DOPS has the next strongest interaction; however, its high bending modulus enables it to resist deformation by the nanoparticle. DOPC has the weakest interaction with the nanoparticle of the three as it has the highest bending modulus and its zwitterionic head groups have strong cohesive interactions. We also observed a nonuniform response of the bilayers: the orientational order of the lipids near the nanoparticle decreases, while that of the lipids away from the nanoparticle increases. The overall thickness and bending modulus of DOPG increased upon contact with the nanoparticle owing to overall stiffening of the bilayer despite local softening, while the average structural and mechanical properties of DOPC and DOPS remain unchanged, which can be explained in part by the greater bilayer bending elasticicty of DOPC and DOPS. The above findings suggest that regions of biological membranes populated by anionic lipids with weaker bending elasticity will be more susceptible to perturbation by TiO₂ nanoparticles than zwitterionic-rich regions.

Semiconductor Quantum Dots as Components of Photoactive Supramolecular Architectures

Luminescent quantum dots (QDs) are colloidal semiconductor nanocrystals consisting of an inorganic core covered by a molecular layer of organic surfactants. Although QDs have been known for more than thirty years, they are still attracting the interest of researchers because of their unique size-tunable optical and electrical properties arising from quantum confinement. Moreover, the controlled decoration of the QD surface with suitable molecular species enables the rational design of inorganic-organic multicomponent architectures that can show a vast array of functionalities. This minireview highlights the recent progress in the use of surface-modified QDs - in particular, those based on cadmium chalcogenides - as supramolecular platforms for light-related applications such as optical sensing, triplet photosensitization, photocatalysis and phototherapy.

Versatile enzymatic assays by switching on the fluorescence of gold nanoclusters

Herein we present a general and turn-on strategy for enzymatic bioassays on the basis of redox state dependent emission of gold nanoclusters (AuNCs). The photoluminescence of AuNCs was quenched obviously by the oxidative ferricyanide while unaffected by its corresponding reduced state, i.e., ferrocyanide. The distinctive quenching abilities for AuNCs by the redox couple (ferricyanide/ferrocyanide) enabled their utility as new fluorescent sensing platforms to detect redox-related phenomena. The proposed protocols were conducted by using the model oxidoreductases of glucose oxidase (GOx) and the enzyme cascade of lactate dehydrogenase (LDH)/diaphorase to catalytically convert ferricyanide to ferrocyanide, which switched on fluorescence of the detection systems. The detection limit for glucose and lactate was found to be as low as 0.12 and 0.09 μM, respectively. This work features the first use of the redox couple of ferricyanide/ferrocyanide in fluorescent bioanalysis, which enables versatile, signal on and highly sensitive/selective detections as compared to the state of the art fluorescently enzymatic sensing platforms. Importantly, considering the significance of ferricyanide/ferrocyanide involves in numerous other oxidoreductases mediated biocatalysis, this protocol has wide versatility that enables combination with oxidoreductases related reactions for biosensing.

Small Peptide-Doxorubicin Co-Assembly for Synergistic Cancer Therapy

Design of elaborated nanomaterials to improve the therapeutic efficacy and mitigate the side effects of chemotherapeutic anticancer drugs, such as Doxorubicin (Dox), is significant for cancer treatment. Here, we describe a co-assembled strategy, where amphiphile short peptides are co-assembled with Doxorubicin to form nanoscale particles for enhanced delivery of Dox. Two kinds of short peptides, Fmoc-FK (FK) and Fmoc-FKK (FKK), are synthesized. Through adjusting the component ratio of peptide and Dox, we obtain two kinds of co-assembled nanoparticles with homogeneous size distributions. These nanoparticles show several distinct characteristics. First, they are pH-responsive as they are stable in alkaline and neutral conditions, however, de-assembly at acidic pH enables selective Dox release in malignant cancer cells. Second, the nanoparticles show an average size of 50–100 nm with positive charges, making them effective for uptake by tumor cells. Moreover, the side effects of Dox on healthy cells are mitigated due to decreased exposure of free-Dox to normal cells. To conclude, the co-assembled peptide-Dox nanoparticles exhibit increased cellular uptake compared to free-Dox, therefore causing significant cancer cell death. Further apoptosis and cell cycle analysis indicates that there is a synergistic effect between the peptide and Doxorubicin.

Mesoporous Silica Nanoparticles for the Treatment of Complex Bone Diseases: Bone Cancer, Bone Infection and Osteoporosis

Bone diseases, such as bone cancer, bone infection and osteoporosis, constitute a major issue for modern societies as a consequence of their progressive ageing. Even though these pathologies can be currently treated in the clinic, some of those treatments present drawbacks that may lead to severe complications. For instance, chemotherapy lacks great tumor tissue selectivity, affecting healthy and diseased tissues. In addition, the inappropriate use of antimicrobials is leading to the appearance of drug-resistant bacteria and persistent biofilms, rendering current antibiotics useless. Furthermore, current antiosteoporotic treatments present many side effects as a consequence of their poor bioavailability and the need to use higher doses. In view of the existing evidence, the encapsulation and selective delivery to the diseased tissues of the different therapeutic compounds seem highly convenient. In this sense, silica-based mesoporous nanoparticles offer great loading capacity within their pores, the possibility of modifying the surface to target the particles to the malignant areas and great biocompatibility. This manuscript is intended to be a comprehensive review of the available literature on complex bone diseases treated with silica-based mesoporous nanoparticles-the further development of which and eventual translation into the clinic could bring significant benefits for our future society.

Rare-earth metal–organic frameworks: from structure to applications

In the past 30 years, rare-earth metal–organic frameworks (MOFs) have been gaining attention owing to their diverse chemical structures, and tunable properties.

The influence of structural gradients in large pore organosilica materials on the capabilities for hosting cellular communities

Cells exist in the so-called extracellular matrix (ECM) in their native state, and numerous future applications require reliable and potent ECM-mimics. A perspective, which goes beyond ECM emulation, is the design of a host-material with features which are not accessible in the biological portfolio. Such a feature would, for instance, be the creation of a structural or chemical gradient, and to explore how this special property influences the biological processes. First, we wanted to test if macroporous organosilica materials with appropriate surface modification can act as a host for the implementation of human cells like HeLa or LUHMES. It was possible to use a commercially available polymeric foam as a scaffold and coat it with a thiophenol-containing organosilica layer, followed by biofunctionalization with biotin using click chemistry and the subsequent coupling of streptavidin–fibronectin to it. More importantly, deformation of the scaffold allowed the generation of a permanent structural gradient. In this work, we show that the structural gradient has a tremendous influence on the capability of the described material for the accommodation of living cells. The introduction of a bi-directional gradient enabled the establishment of a cellular community comprising different cell types in spatially distinct regions of the material. An interesting perspective is to study communication between cell types or to create cellular communities, which can never exist in a natural environment.

Chemical and structural gradients in biofunctionalized organosilica–polymer nanocomposites control cell adhesion properties and open perspectives for artificial cellular community systems.