A Smart Nanoreactor Based on an O2-Economized Dual Energy Inhibition Strategy Armed with Dual Multi-stimuli-Responsive "Doorkeepers" for Enhanced CDT/PTT of Rheumatoid Arthritis.

Activated fibroblast-like synovial (FLS) cells are regarded as an important target for rheumatoid arthritis (RA) treatment via starvation therapy mediated by glucose oxidase (GOx). However, the hypoxic RA-FLS environment greatly reduces the oxidation process of glucose and leads to a poor therapeutic effect of the GOx-based starvation therapy. In this work, we designed a hollow mesoporous copper sulfide nanoparticles (CuS NPs)-based smart GOx/atovaquone (ATO) codelivery system (named as V-HAGC) targeting RA-FLS cells to realize a O2-economized dual energy inhibition strategy to solve the limitation of GOx-based starvation therapy. V-HAGC armed with dual multi-stimuli-responsive "doorkeepers" can guard drugs intelligently. Once under the stimulation of photothermal and acidic conditions at the targeted area, the dual intelligent responsive "doors" would orderly open to realize the controllable release of drugs. Besides, the efficacy of V-HAGC would be much improved by the additional chemodynamic therapy (CDT) and photothermal therapy (PTT) stimulated by CuS NPs. Meanwhile, the upregulated H2O2 and acid levels by starvation therapy would promote the Fenton-like reaction of CuS NPs under O2-economized dual energy inhibition, which could enhance the PTT and CDT efficacy as well. In vitro and in vivo evaluations revealed V-HAGC with much improved efficacy of this combination therapy for RA. In general, the smart V-HAGC based on the O2-economized dual energy inhibition strategy combined with enhanced CDT and PTT has the potential to be an alternative methodology in the treatment of RA.

An Assessment of In-vitro and In-vivo Evaluation Methods for Theranostic Nanomaterials.

Nanoparticles (NPs) as nanocarriers have emerged as novel and promising theranostic agents. The term theranostics revealed the properties of NPs capable of diagnosing the disease at an early stage and/or treating the disease. Such NPs are usually developed employing a surface engineering approach. The theranostic agents comprise NPs loaded with a drug/diagnostic agent that delivers it precisely to the target site. Theranostics is a field with promising results in enhancing therapeutic efficacy facilitated through higher payload at the targeted tissue, reduced dose, and dose-dependent side effects. However, controversies in terms of toxicity and size-dependent properties have often surfaced for NPs. Thus, a stringent in-vitro and in-vivo evaluation is required to develop safe and non-toxic NPs as theranostic agents. The review also focuses on the various entry points of NPs in the human system and their outcomes, including toxicity. It elaborates the evaluation criteria to ensure the safe use of NPs for diagnostic and therapeutic purposes.

Assessment of the protective effect of yeast cell wall ß-glucan encapsulating humic acid nanoparticles as an aflatoxin B1 adsorbent in vivo.

This study aimed to assess the protective effect of encapsulating humic acid-iron complexed nanoparticles (HA-Fe NPs) inside glucanmannan lipid particles (GMLPs) extracted from yeast cell wall against aflatoxin B (AFB1 ) toxicity in vivo. Four groups of male Sprague-Dawley rats were treated orally for 2 weeks included the control group, AFB1 treated group (80 µg/kg b.w); GMLP/HA-Fe NPs treated group (0.5 mg/kg b.w), and the group treated with AFB1 plus GMLP/HA-Fe NPs. GMLPs are empty 3-4 micron permeable microspheres that provide an efficient system for the synthesis and encapsulation of AFB1 -absorbing nanoparticles (NPs). Humic acid nanoparticles (HA-NPs) were incorporated inside the GMLP cavity by complexation with ferric chloride. In vivo study revealed that AFB1 significantly elevated serum alanine aminotransferase, aspartate aminotransferase, creatinine, uric acid, urea, cholesterol, triglycerides, LDL, malondialdehyde, and nitric oxide. It significantly decreased total protein, high-density lipoprotein, hepatic and renal CAT and glutathione peroxidase content and induced histological changes in the liver and kidney (p ≤ 0.05). The coadministration of the synthesized formulation GMLP/HA-Fe NPs with AFB1 has a protective effect against AFB1 -induced hepato-nephrotoxicity, oxidative stress and histological alterations in the liver and kidney.

Bench-to-Bedside in Vascular Medicine: Optimizing the Translational Pipeline for Patients With Peripheral Artery Disease.

Peripheral arterial disease is a growing worldwide problem with a wide spectrum of clinical severity and is projected to consume >$21 billion per year in the United States alone. While vascular researchers have brought several therapies to the clinic in recent years, few of these approaches have leveraged advances in high-throughput discovery screens, novel translational models, or innovative trial designs. In the following review, we discuss recent advances in unbiased genomics and broader omics technology platforms, along with preclinical vascular models designed to enhance our understanding of disease pathobiology and prioritize targets for additional investigation. Furthermore, we summarize novel approaches to clinical studies in subjects with claudication and ischemic ulceration, with an emphasis on streamlining and accelerating bench-to-bedside translation. By providing a framework designed to enhance each aspect of future clinical development programs, we hope to enrich the pipeline of therapies that may prevent loss of life and limb for those with peripheral arterial disease.

In vitro anti-leukemic assessment and sustained release behaviour of cytarabine loaded biodegradable polymer based nanoparticles.

AIMS: The study aimed to develop, characterize, and evaluate poly (ɛ-caprolactone) (PCL) based nanoparticles for the sustained release behaviour of cytarabine and to investigate the in vitro anti-cancer influence on KG-1 leukemic cell line. MATERIALS AND METHODS: Nanoprecipitation method was used for the preparation of cytarabine loaded PCL nanoparticles. The developed nanoparticles were characterized for physicochemical properties and the anti-leukemic effect on the KG-1 cell line was evaluated. KEY FINDINGS: A total number of five formulations were prepared with size range from 120.5 ± 1.18 to 341.5 ± 3.02, entrapment efficiency (41.31 ± 0.49 to 62.28 ± 0.39%), spherical morphology, negative zeta potentials, considerable particle size distribution, compatibility between the drug and excipients and thermal stability. X-ray diffraction analysis confirmed the successful incorporation of cytarabine in PCL polymer. In vitro drug release in phosphate buffer saline (pH 7.4) showed initial burst release followed by sustained release up to 48 h. The sustained release behaviour efficiently increased the toxicity of cytarabine-loaded PCL nanoparticles to KG-1 (leukemic) and MCF-7 (breast cancer) cell lines in time dependent manner with lower IC50 values than that of drug solution. The flow cytometry study revealed the better apoptotic activity of cytarabine loaded PCL nanoparticle against treated KG-1 cell line. The western blot analysis confirmed the upregulation of cleaved caspase-3 and downregulation of Bcl-2 protein. SIGNIFICANCE: The experimental results suggest that cytarabine loaded PCL nanoparticles is an efficient carrier to prevent the dose associated toxicity while providing sustained release pattern to ensure maximum anti-cancer influence.

Self-Delivery Nanomedicine for O2-Economized Photodynamic Tumor Therapy.

Tumor hypoxia is the Achilles heel of oxygen-dependent photodynamic therapy (PDT), and tremendous challenges are confronted to reverse the tumor hypoxia. In this work, an oxidative phosphorylation inhibitor of atovaquone (ATO) and a photosensitizer of chlorine e6 (Ce6)-based self-delivery nanomedicine (designated as ACSN) were prepared via π-π stacking and hydrophobic interaction for O2-economized PDT against hypoxic tumors. Specifically, carrier-free ACSN exhibited an extremely high drug loading rate and avoided the excipient-induced systemic toxicity. Moreover, ACSN not only dramatically improved the solubility and stability of ATO and Ce6 but also enhanced the cellular internalization and intratumoral permeability. Abundant investigations confirmed that ACSN effectively suppressed the oxygen consumption to reverse the tumor hypoxia by inhibiting mitochondrial respiration. Benefiting from the synergistic mechanism, an enhanced PDT effect of ACSN was observed on the inhibition of tumor growth. This self-delivery system for oxygen-economized PDT might be a potential appealing clinical strategy for tumor eradication.

Photoacoustic ratiometric assessment of mitoxantrone release from theranostic ICG-conjugated mesoporous silica nanoparticles.

A theranostic nanosystem based on indocyanine green (ICG) covalently conjugated to mesoporous silica nanoparticles (MSNs) loaded with the anticancer drug mitoxantrone (MTX) is proposed as an innovative photoacoustic probe. Taking advantage of the characteristic PA signal displayed by both ICG and MTX, a PA-ratiometric approach was applied to assess the drug release profile from the MSNs. After complete in vitro characterization of the nanoprobe, a proof-of-concept study has been carried out in tumour-bearing mice to evaluate in vivo its effectiveness for cancer imaging and chemotherapeutic agent delivery.

An in vitro Assessment of Thermo-Reversible Gel Formulation Containing Sunitinib Nanoparticles for Neovascular Age-Related Macular Degeneration.

Anti-vascular endothelial growth factor agents have been widely used to treat several eye diseases including age-related macular degeneration (AMD). An approach to maximize the local concentration of drug at the target site and minimize systemic exposure is to be sought. Sunitinib malate, a multiple receptor tyrosine kinase inhibitor was encapsulated in poly(lactic-co-glycolic acid) nanoparticles to impart sustained release. The residence time in vitreal fluid was further increased by incorporating nanoparticles in thermo-reversible gel. Nanoparticles were characterized using TEM, DSC, FTIR, and in vitro drug release profile. The cytotoxicity of the formulation was assessed on ARPE-19 cells using the MTT assay. The cellular uptake, wound scratch assay, and VEGF expression levels were determined in in vitro settings. The optimized formulation had a particle size of 164.5 nm and zeta potential of - 18.27 mV. The entrapment efficiency of 72.0% ± 3.5% and percent drug loading of 9.1 ± 0.7% were achieved. The viability of ARPE-19 cells was greater than 90% for gel loaded, as such and blank nanoparticles at 10 µM and 20 µM concentration tested, whereas for drug solution viability was found to be 83% and 71% respectively at above concentration. The cell viability results suggest the compatibility of the developed formulation. Evaluation of cellular uptake, wound scratch assay, and VEGF expression levels for the developed formulations indicated that the formulation had higher uptake, superior anti-angiogenic potential, and prolonged inhibition of VEGF activity compared with drug solution. The results showed successful development of sunitinib-loaded nanoparticle-based thermo-reversible gel which may be used for the treatment of neovascular AMD.

Tumor Homing Reactive Oxygen Species Nanoparticle for Enhanced Cancer Therapy.

Multifunctional nanoparticles that carry chemotherapeutic agents can be innovative anticancer therapeutic options owing to their tumor-targeting ability and high drug-loading capacity. However, the nonspecific release of toxic DNA-intercalating anticancer drugs from the nanoparticles has significant side effects on healthy cells surrounding the tumors. Herein, we report a tumor homing reactive oxygen species nanoparticle (THoR-NP) platform that is highly effective and selective for ablating malignant tumors. Sodium nitroprusside (SNP) and diethyldithiocarbamate (DDC) were selected as an exogenous reactive oxygen species (ROS) generator and a superoxide dismutase 1 inhibitor, respectively. DDC-loaded THoR-NP, in combination with SNP treatment, eliminated multiple cancer cell lines effectively by the generation of peroxynitrite in the cells (>95% cell death), as compared to control drug treatments of the same concentration of DDC or SNP alone (0% cell death). Moreover, the magnetic core (ZnFe2O4) of the THoR-NP can specifically ablate tumor cells (breast cancer cells) via magnetic hyperthermia, in conjunction with DDC, even in the absence of any exogenous RS supplements. Finally, by incorporating iRGD peptide moieties in the THoR-NP, integrin-enriched cancer cells (malignant tumors, MDA-MB-231) were effectively and selectively killed, as opposed to nonmetastatic tumors (MCF-7), as confirmed in a mouse xenograft model. Hence, our strategy of using nanoparticles embedded with ROS-scavenger-inhibitor with an exogenous ROS supplement is highly selective and effective cancer therapy.

Brain-targeted glycyrrhizic-acid-loaded surface decorated nanoparticles for treatment of cerebral ischaemia and its toxicity assessment.

OBJECTIVE: Enhancement of CS-GA-PCL-NPs (Glycyrrhizic Acid-encapsulated-chitosan-coated-PCL-Nanoparticles) bioavailability in brain. METHODS: Double emulsification solvent evaporation method in order to develop CS-PCL-NPs (Chitosan-coated-PCL-Nanoparticles) followed by characterization of particle size and distribution, zeta potential, encapsulation efficiency and drug release (in vitro). To determine drug-uptake and its pharmacokinetic profile in brain as well as plasma, UHPLC (triple quadrupole Q-trap) MS/MS method was developed and optimized for CS-GA-PCL-NPs as well as to follow-up examined effective role of optimized NPs in reduction of all brain injury parameters after MCAO through the grip strength, locomotor activity, inflammatory cytokines levels, measurement of infarction volume and histopathological changes in neurons with safety/toxicity after i.n. in animals. RESULTS: The developed NPs showed an average particle size, entrapment efficiency with PDI (polydispersity index) of 201.3 ± 4.6 nm, 77.94 ± 5.01% and 0.253 ± 0.019, respectively. Higher mucoadhesive property for CS-GA-PCL-NPs as compared to conventional and homogenized nanoformulations was observed whereas an elution time of 0.37 min and m/z of 821.49/113.41 for GA along with an elution time of 1.94 min and m/z of 363.45/121.40 was observed for hydrocortisone i.e. Internal standard (IS). Similarly, %CV i.e. inter and intra assay i.e. 0.49-4.41%, linear dynamic range (10-2000 ng/mL) and % accuracy of 90.00-99.09% was also observed. AUC0-24 with augmented Cmax was noted (**p < .01), in Wistar rat brain as compared to i.v. treated group during pharmacokinetics studies. In MCA-occluded rats, enhanced neurobehavioral activity i.e. locomotor and grip strength along with a decrease in cytokines level (TNF-α and IL-1ß) was observed, following i.n. administration. CONCLUSIONS: CS-coated-GA-loaded-PCL-NPs when administered i.n. enhanced the bioavailability of the drug in rat brain as compared to i.v. administration. The observation from toxicity study concludes; the developed NPS are safe and free of any health associated risk.

Novel, cost-effective, Cu-doped calcium silicate nanoparticles for bone fracture intervention: Inherent bioactivity and in vivo performance.

Copper (Cu)-doped calcium silicate nanoparticles were synthesized by a wet precipitation method as economical bone fracture filler. The aim was to improve the overall physicochemical properties, bioactivity, and biological performance of the bone fracture filler prepared herein. The synthesized nanoparticles were evaluated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM). The bioactivity of the prepared nanoparticles was investigated after immersion in simulated body fluid (SBF) by means of inductively coupled plasma (ICP), SEM coupled with energy dispersive X-rays (EDX), and FTIR. The size and bioactivity of the prepared nanoparticles after 15 days of immersion in SBF was dependent on the Cu concentrations. The fracture healing ability of the fabricated nanoparticles on adult aged male Wistar rats was enhanced by the presence of copper. All the obtained results are of high relevance for fabricating improved Cu-doped calcium silicate nanoparticles (∼50 nm) as low cost bone fracture filler. In addition, the in vivo study presented complete healing of the tibiae bone with normal architecture of bone tissue specifically calcium silicate nanoparticles doped with 3% and 5% Cu. Hence, the presence of copper is a promising tactic for improving the biological properties of calcium silicate. Therefore, the designed nanoparticles have huge potential for the treatment of bone fractures. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 388-399, 2019.

Reflections on FDA Draft Guidance for Products Containing Nanomaterials: Is the Abbreviated New Drug Application (ANDA) a Suitable Pathway for Nanomedicines?

The US Food and Drug Administration (FDA) recently released a draft guidance for industry titled "Drug Products, Including Biological Products, that Contain Nanomaterials." The FDA's attention to the unique safety and efficacy aspects of drugs containing nanomaterials is commendable. This Draft Guidance succeeds in acknowledging the complexity of these products, as well as the challenges associated with approving safe and therapeutically equivalent complex generic versions. However, the challenge posed by the manufacturing process for drugs containing nanomaterials is insufficiently addressed. The critical quality attributes of such products cannot be properly defined, and therefore it is not possible to design informative comparative physicochemical assessments for equivalence. As a consequence, the 505(j) Abbreviated New Drug Application (ANDA) pathway, currently advised as the standard from the FDA, is not suitable for the approval of complex generic products. Drawing from the successful story of biologics, we propose instead a stepwise totality-of-evidence approach, demonstrating similarity and including clinical studies when deemed necessary, as an appropriate alternative to the 505(j) ANDA pathway.

Paclitaxel as Albumin-Bound Nanoparticles with Gemcitabine for Untreated Metastatic Pancreatic Cancer: An Evidence Review Group Perspective of a NICE Single Technology Appraisal.

As part of the single technology appraisal (STA) process, the National Institute for Health and Care Excellence (NICE) invited Celgene Ltd to submit clinical and cost-effectiveness evidence for paclitaxel as albumin-bound nanoparticles (Nab-Pac) in combination with gemcitabine (Nab-Pac + Gem) for patients with untreated metastatic pancreatic cancer. The STA was a review of NICE's 2015 guidance (TA360) in which Nab-Pac + Gem was not recommended for patients with untreated metastatic pancreatic cancer. The review was prompted by a proposed Patient Access Scheme (PAS) discount on the price of Nab-Pac and new evidence that might lead to a change in the guidance. The Liverpool Reviews and Implementation Group at the University of Liverpool was the Evidence Review Group (ERG). This article summarises the ERG's review of the company's evidence submission for Nab-Pac + Gem, and the Appraisal Committee (AC) decision. The final scope issued by NICE listed three comparators: gemcitabine monotherapy (Gem), gemcitabine in combination with capecitabine (Gem + Cap), and a combination of oxaliplatin, irinotecan, leucovorin and fluorouracil (FOLFIRINOX). Clinical evidence for the comparison of Nab-Pac + Gem versus Gem was from the phase III CA046 randomized controlled trial. Analysis of progression-free survival (PFS) and overall survival (OS) showed statistically significant improvement for patients treated with Nab-Pac + Gem versus Gem. Clinical evidence for the comparison of Nab-Pac + Gem versus FOLFIRINOX and versus Gem + Cap was derived from a network meta-analysis (NMA). Results of the NMA did not indicate a statistically significant difference in OS or PFS for the comparison of Nab-Pac + Gem versus either Gem + Cap or FOLFIRINOX. The ERG's main concerns with the clinical effectiveness evidence were difficulties in identifying the patient population for whom treatment with Nab-Pac + Gem is most appropriate, and violation of the proportional hazards (PH) assumption in the CA046 trial. The ERG highlighted methodological issues in the cost-effectiveness analysis pertaining to the modelling of survival outcomes, estimation of drug costs and double counting of adverse-event disutilities. The AC accepted all the ERG's amendments to the company's cost-effectiveness model; however, these did not make important differences to the incremental cost-effectiveness ratios (ICERs). The company's base-case ICER was £46,932 per quality-adjusted life-year (QALY) gained for the comparison of Nab-Pac + Gem versus Gem. Treatment with Nab-Pac + Gem was dominated both by treatment with Gem + Cap and with FOLFIRINOX in the company's base case. The AC concluded that the most plausible ICER for treatment with Nab-Pac + Gem versus Gem was in the range of £41,000-£46,000 per QALY gained. The AC concluded that Nab-Pac + Gem was not cost effective compared with Gem + Cap or FOLFIRINOX, and accepted that treatment with Nab-Pac + Gem met the end-of-life criteria versus Gem but did not consider Nab-Pac + Gem to meet the end-of-life criteria compared with Gem + Cap or FOLFIRINOX. The AC also concluded that although patients who would receive Nab-Pac + Gem rather than FOLFIRINOX or Gem + Cap were difficult to distinguish, they were identifiable in clinical practice. The AC recommended treatment with Nab-Pac + Gem for patients with untreated metastatic pancreatic cancer for whom other combination chemotherapies were unsuitable and who would otherwise receive Gem.

Albumin-Assisted Method Allows Assessment of Release of Hydrophobic Drugs From Nanocarriers.

Polymeric nanoparticles have been extensively studied as drug delivery vehicles both in vitro and in vivo for the last two decades. In vitro methods to assess drug release profiles usually utilize degradation of nanoparticles in aqueous medium, followed by the measurement of the concentration of the released drug. This method, however, is difficult to use for drugs that are poorly water soluble. In this study, a protocol for measuring drug release kinetic using albumin solution as the medium is described. Albumin is a major blood transport protein, which mediates transport of many lipid soluble compounds including fatty acids, hormones, and bilirubin. The use of a dialysis-based system utilizing albumin dialysate solution allows hydrophobic drug release from a diverse set of drug delivery modalities is demonstrated. The method using liposomes and PLGA nanoparticles as drug carriers, and two model hydrophobic drugs, 17ß-estradiol, and dexamethasone is validated.

Reactogenicity and safety assessment of an attenuated nanovaccine against scorpion envenomation: Preclinical study.

An attenuated nanovaccine (Nps - V∗) has been developed to protect humans from fatal scorpion envenomation in at-risk regions. This study was conducted to evaluate the toxicity and the local reactogenicity of the Nps - V∗ nanovaccine developed against Androctonus australis hector (Aah) venom. Assessment of the systemic inflammatory response and serum cytokine levels were evaluated in vaccinated mice with 100µg of irradiated Aah venom (V∗) encapsulated or not into polymeric calcium-alginate nanoparticles (Nps) and injected by subcutaneous (s.c) route. The local reactogenicity was evaluated by dermal Draize observations and skin tissue analysis at the injection site of vaccinated rabbits with 250 or 500µg of V∗-loaded into Nps. All animals gained weight and had normal food consumption during the study. Additionally, results showed that the nanoformulation Nps - V∗ did not cause clinical evidence of systemic toxicity in mice or rabbits, a transient edema/erythema at the injection site was only recorded as treatment-related reactogenicity. These results indicated a favorable safety profile for Nps - V∗ and supported its use in superior animal tests, then in a Phase 1 clinical trial.

Adjuvants for allergy immunotherapeutics.

Allergic diseases are reaching epidemic proportions in developed countries. In particular, food allergy is increasing in prevalence and severity, thus becoming an important socioeconomic burden. Numerous cell types and cell populations, which form an intricate and balanced network, are involved in an immune response. This balance is occasionally disturbed, leading to the onset of different diseases, such as allergic diseases. Antihistamines and corticosteroids provide some degree of relief from the symptoms of allergic conditions. However, the only treatment that can revert the disease is immunotherapy. Nevertheless, specific immunotherapy has at least 2 major drawbacks: it is time-consuming, and it can produce local and even systemic allergic side effects. Immunotherapy's potential goes beyond our current knowledge of the immune response; nevertheless, we can still design strategies to reach a safer immune modulation for treating allergies. This review deals with the use of adjuvants to reduce the undesirable side effects associated with specific allergen immunotherapy. For example, nanoparticles used as immunoadjuvants are offering promising results in preclinical assays.

Updated Regulatory Considerations for Nanomedicines.

BACKGROUND: Nanomedicine is a branch which deals with medicinal products, devices, nonbiological complex drugs and antibody-nanoparticle conjugates and general health products that are manufactured using nanotechnology. OBJECTIVE: Nano-medicine provides the same efficacies as traditional medicines owing to their improved solubility and bioavailability with reduced dosages. However, there are currently safety concerns due to the difficulties related to nanomaterial characterization; this might be the reason for unawareness of such medicines among the patients. The absence of clear regulatory guidelines further complicates matters, as it makes the path to registering them with regulatory bodies difficult. However, some products have overcome these obstacles and have been registered. While there are many international initiatives to harmonize the regulatory requirements and helps the industry to determine the most important characteristics that influence in vivo product performance. CONCLUSION: This review focuses on the various types of nanopharmaceuticals, and developments process with strategies tailored to upcoming regulations may satisfy the patients' needs.

Characterization and cellular studies of molecular nanoparticle of iron (III)-tannic complexes; toward a low cost magnetic resonance imaging agent.

Herein, a new magnetic resonance imaging (MRI) agent based on molecular nanoparticles of iron(III)-tannic complexes (Fe-TA NPs) is reported. The paramagnetic and molecularlike Fe-TA NPs were successfully synthesized at room temperature within a few minutes without the use of any toxic agents or expensive equipment. The coordination states of the Fe-TA NPs were pH-dependent. The r1 relaxivity values of the bis-dominated and tris-dominated structures of the Fe-TA NPs were determined to be 6.31 and 5.24 mM-1 s-1, respectively, by using a Philips Achieva 1.5T MRI scanner. The Fe-TA NPs were 177 ± 12 nm in diameter (hydrodynamic size) with a zeta potential value of -28 ± 0.9 mV, dispersing very well in aqueous solution and were highly stable in phosphate buffered saline buffer (pH 7.4) containing competitive ligands and metals. From in vitro studies, it was evident that the Fe-TA NPs exhibited good biocompatibility, with high cellular uptake in HepG2 cells. Clearly, the Fe-TA NPs were found to induce signal enhancement in the T1-weighted image of the HepG2 cells. As a result, it can be stated that the Fe-TA NPs may have the potential for being developed as low-cost and clinically translatable magnetic resonance imaging agents in the near future.

Ethical issues in nanomedicine: Tempest in a teapot?

Nanomedicine offers remarkable options for new therapeutic avenues. As methods in nanomedicine advance, ethical questions conjunctly arise. Nanomedicine is an exceptional niche in several aspects as it reflects risks and uncertainties not encountered in other areas of medical research or practice. Nanomedicine partially overlaps, partially interlocks and partially exceeds other medical disciplines. Some interpreters agree that advances in nanotechnology may pose varied ethical challenges, whilst others argue that these challenges are not new and that nanotechnology basically echoes recurrent bioethical dilemmas. The purpose of this article is to discuss some of the ethical issues related to nanomedicine and to reflect on the question whether nanomedicine generates ethical challenges of new and unique nature. Such a determination should have implications on regulatory processes and professional conducts and protocols in the future.

PAMAM dendrimers: destined for success or doomed to fail? Plain and modified PAMAM dendrimers in the context of biomedical applications.

PAMAM (polyamidoamine) dendrimers are commonly considered promising polymers that can be successfully used in various biomedical applications. Nevertheless, direct clinical adaptations of plain unmodified PAMAM dendrimers may be limited at present, mainly because of their toxicity, unpredictable behavior in living organisms, unknown bioavailability, biocompatibility or pharmacokinetic profile, problematic therapeutic dose selection, or high cost of production. On the basis of our studies concerning the possible use of unmodified PAMAM dendrimers as the scavengers of glucose and carbonyl stress in animal models of human pathology, as well as considering available literature on experimental data of other researchers, we have prepared the brief critical review of the biomedical activities of these unmodified compounds and their most alluring derivatives, especially in the context of possible future perspectives of PAMAMs. Thus, on the pages of this review, we made an attempt to briefly summarize obstacles, emerging from experimental, technical, and human limitations, that may, to some extent, restrain our belief in a brighter future of plain amine-terminated PAMAM dendrimers.