Tumour-specific hybrid nanoparticles in therapy of breast cancer

In this study, salicylic acid (SA) dopped into poly(3-hydroxybutyrate) (PHB) and prepared nanoparticles (NPs) to increase encapsulation efficiency, anti-cancer activity of caffeic acid (Caff), and folic acid (FA) for breast cancer treatment. NPs were prepared by solvent evaporation method and characterised by FTIR, DSC, SEM, and entrapment-loading efficiencies. The mean diameter, polydispersity index (PDI), and zeta potential (ZP) were evaluated by dynamic light scattering (DLS). In vitro release and stability studies were done via eppendorf method. The cytotoxicity, cell dead and internalisation of NPs were shown by MTT, fluorescein and confocal microscopy. The diameter and ZP of NPs were 172 ± 7 nm and -29 ± 0.38 mV. The entrapment efficiencies of 5 and 10 Caff NPs were 79 ± 0.23% and 70 ± 0.42%. NPs showed good stability within 30 d and sustained release over 25 d. FA-5Caff NPs showed 37 ± 0.3% viability on MCF-7. FA-Caff NPs were identified as promising carrier system for breast cancer therapy.

Effectiveness of carbonic anhydrase inhibitor loaded nanoparticles in the treatment of diabetic retinopathy

Diabetic Retinopathy (DRP) is a disease consisting of all the structural and functional changes that develop in the retinal layer of the eye due to diabetes. DRP is the most important cause of blindness between the ages of 20-74 in the world, and the most successful standard treatment option in the treatment of DRP is intravitreal injections. To synthesize acetazolamide loaded nanoparticles to be applied intravitreal treatment of DRP and to examine thein vitroefficacy of the nanoparticles. ACZ loaded PHBV nanoparticles (PHBV-ACZ NPs) formulations were prepared. Nanoparticles with a particle size of 253.20 ± 0.55 nm. A DRP model was established and characterized in HRMEC cells. The effect of the nanoparticles on permeability has been investigated and carrier proteins in BRB due to the development of DRP has been investigated. To establish thein vitroDRP model, HRMEC was stimulated with Recombinant human 165 Vascular Endothelial Growth Factor (VEGF), thereby temporarily reducing the expression levels of endothelial junction proteins, increasing the number of intercellular spaces in the monolayers of HRMECs. It was determined that after the cells were exposed to Carbonic anhydrase inhibitors (CAI) loaded nanoparticles, permeability decreased and protein expression increased.

Ocular pharmacokinetics and toxicity of nanoparticular acetazolamide: In vivo distribution and safety of PHBV-ACZ nanoparticle

Diabetic macular edema (DME) is defined as fluid accumulation in the macular region, between the retinal layers, due to many diseases, especially diabetes. DME is one of the major complications of diabetic retinopathy (DRP). Carbonic anhydrase inhibitors (CAI) are a pharmaceutical agent used in different fields, especially glaucoma treatment. Acetazolamide (ACZ), which is a CAI, is an active substance that has been used off-label for many years in the treatment of macular edema due to diabetes and many other diseases. The low solubility and bioavailability of ACZ limit its use in the treatment of DME. In this study, a nanoparticulate formulation was developed that would increase the solubility and bioavailability of ACZ and allow it to be administered intravitreally. ACZ was loaded on poly(3-hydroxybutyrate-co-3-Hydroxyvalerate) (PHBV) nanoparticles and the loading efficiency was 71.58 ± 1.22%. Toxicity of nanoparticles after intravitreal application was evaluated with anterior segment and posterior segment examination findings, intraocular pressure (IOP) measurements and electrophysiological tests. At the end of the 3-month follow-up, electroretinography (ERG) measurements demonstrated that ACZ loaded PHBV (PHBV-ACZ) nanoparticles did not cause loss of function in retinal cells. On histological examination, rare degenerative changes were observed in several cell groups. In addition, pharmacokinetic studies were performed to determine the tissue distribution of ACZ at various periods. ACZ was identified in vitreous humor and retina at the highest concentration. Based on our results, the prepared nanoparticle formulation can release long-term CAI for DRP therapy and accordingly can reduce the need for monthly intravitreal injections.

Biological Activities and Biocompatibility Properties of Eu(OH)3 and Tb(OH)3 Nanorods: Evaluation for Wound Healing Applications

Rare earth elements have shown promising results in both bio-imaging and therapy applications due to their superior magnetic, catalytic, and optical properties. In recent years, since lanthanide-based nanomaterials have effective results in wound healing, it has become necessary to investigate the different properties of these nanoparticles. The aim of this study is to investigate the antimicrobial, antibiofilm, and biocompability of Eu(OH)₃ and Tb(OH)₃ nanorods, which have a high potential by triggering angiogenesis and providing ROS activity, especially in wound healing. For this purpose, nanorods were obtained by the microwave-assisted synthesis method. Structural characterizations of Eu(OH)₃ and Tb(OH)₃ nanorods were performed by FT-IR, XRD, and TG-DTA methods, and morphological characterizations were performed by SEM-EDX. Microorganisms that are likely to be present in the wound environment were selected for the antimicrobial activities of the nanorods. The highest efficiency of nanorods with the disc diffusion method was shown against Pseudomonas aeruginosa ATCC 27,853 and Candida albicans ATCC 10,231 microorganisms. One of the problems frequently encountered in an infected wound environment is the formation of bacterial biofilm. Eu(OH)₃ nanorods inhibited 77.5 ± 0.43% and Tb(OH)₃ nanorods 76.16 ± 0.60% of Pseudomonas aeruginosa ATCC 27,853 biofilms. These results show promise for the development of biomaterials with superior properties by adding these nanorods to wound dressings that will be developed especially for wounds with microbial infection. Eu(OH)₃ nanorods are more toxic than Tb(OH)₃ nanorods on NCTC L929 cells. At concentrations of 500 µg/ml and above, both nanorods are toxic to cells.

Evaluation of sphingolipid metabolism on diabetic retinopathy

Purpose:

To evaluate the aqueous and serum levels of sphingolipid metabolism mediators such as sphingosine 1 phosphate (S1P), sphingosine kinase 1 (SK1), sphingosine kinase 2 (SK2), ceramide kinase (CK), and acid sphingomyelinase (ASM) which are thought to take part in diabetic retinopathy (DR) pathogenesis, and development and severity of diabetic retinopathy (DR) in patients with type 2 diabetes.

Methods:

A prospective cross-sectional study was conducted on type 2 diabetic and control patients who underwent cataract surgery. Three different subgroups, namely, non-diabetic retinopathy (NDR), non-proliferative diabetic retinopathy (NPDR), and proliferative diabetic retinopathy (PDR), were allocated and the S1P, SK1, SK2, CK, and ASM levels in the serum and aqueous humor samples of diabetic and control patients were evaluated. Kolmogorov-Smirnov test, Student's t-test, and Mann-Whitney U test were used for the statistical analysis of the study.

Results:

Among a total of 45 patients, including diabetic and control patients, the mean aqueous levels of SK1 (P < 0.001), SK2 (P = 0.012), ASM (P = 0.006), and CK (P = 0.002) were higher in all diabetic patients. The mean aqueous level of S1P was significantly higher in the PDR group than in other groups (P = 0.003). The mean aqueous levels of SK2 and ASM also increased in the NDR, NPDR, and PDR subgroups, respectively (P < 0.001). In addition, the mean serum levels of S1P, SK1, and ASM were higher in the diabetic patients (P = 0.015, P = 0.034, and P = 0.006, respectively).

Conclusion:

According to our findings, both aqueous and serum levels of S1P, SK1, and ASM and only the aqueous levels of SK2 and CK were higher in diabetic patients. This study suggested that sphingolipid metabolism may play an important role in DR pathogenesis.

Three-dimensional MRI-based treatment planning approach for non-invasive ocular proton therapy

PURPOSE

To develop a high-resolution three-dimensional (3D) magnetic resonance imaging (MRI)-based treatment planning approach for uveal melanomas (UM) in proton therapy.

MATERIALS/METHODS

For eight patients with UM, a segmentation of the gross tumor volume (GTV) and organs-at-risk (OARs) was performed on T1- and T2-weighted 7 Tesla MRI image data to reconstruct the patient MR-eye. An extended contour was defined with a 2.5-mm isotropic margin derived from the GTV. A broad beam algorithm, which we have called πDose, was implemented to calculate relative proton absorbed doses to the ipsilateral OARs. Clinically favorable gazing angles of the treated eye were assessed by calculating a global weighted-sum objective function, which set penalties for OARs and extreme gazing angles. An optimizer, which we have named OPT'im-Eye-Tool, was developed to tune the parameters of the functions for sparing critical-OARs.

RESULTS

In total, 441 gazing angles were simulated for every patient. Target coverage including margins was achieved in all the cases (V95%  > 95%). Over the whole gazing angles solutions space, maximum dose (Dmax ) to the optic nerve and the macula, and mean doses (Dmean ) to the lens, the ciliary body and the sclera were calculated. A forward optimization was applied by OPT'im-Eye-Tool in three different prioritizations: iso-weighted, optic nerve prioritized, and macula prioritized. In each, the function values were depicted in a selection tool to select the optimal gazing angle(s). For example, patient 4 had a T2 equatorial tumor. The optimization applied for the straight gazing angle resulted in objective function values of 0.46 (iso-weighted situation), 0.90 (optic nerve prioritization) and 0.08 (macula prioritization) demonstrating the impact of that angle in different clinical approaches.

CONCLUSIONS

The feasibility and suitability of a 3D MRI-based treatment planning approach have been successfully tested on a cohort of eight patients diagnosed with UM. Moreover, a gaze-angle trade-off dose optimization with respect to OARs sparing has been developed. Further validation of the whole treatment process is the next step in the goal to achieve both a non-invasive and a personalized proton therapy treatment.

Evaluation of electrocardiographic ventricular repolarization parameters in extreme obesity

BACKGROUND AND OBJECTIVES

The risk of sudden death and cardiac arrhythmia increases in morbidly obese patients. We aimed to evaluate the marker of arrhythmias such as Tp-e/QT, Tp-e/QTc, Tp-e/JT and Tp-e/JTc ratios in extreme obesity.

METHODS

The study included 41 extremely obese patients and 41 control subjects. QTmax, QTmin, QRS, JT and Tp-e intervals were measured od 12‑lead electrocardiographies. In addition, Tp-e/QT, Tp-e/QTc, Tp-e/JT and Tp-e/JTc rates and QTc, cQTd and JTc intervals were calculated.

RESULTS

Tp-e interval (79.2 ± 9.7 ms (milisecond) vs. 68.6 ± 8.1, p < 0.001), QTc interval (395.9 ± 18.8 vs. 377.9 ± 19.3 ms, p < 0.001), JTc interval (317.1 ± 27.0 vs. 297.4 ± 23.2 ms, p = 0.001), Tp-e/QT ratio (0.22 ± 0.03vs. 0.19 ± 0.02, p < 0.001), Tp-e/QTc ratio (0.20 ± 0.26vs. 0.18 ± 0.02, p = 0.001), Tp-e/JT ratio (0.29 ± 0.04 vs. 0.25 ± 0.03, p < 0.001), TPe/JTc ratio (0.25 ± 0.04 vs. 0.23 ± 0.03, p = 0.018), QTd (32.8 ± 10 vs.15 ± 6.4 ms, p < 0.001) and cQTd (70.0 ± 30.1 vs. 31.3 ± 22.4 ms, p < 0.001) were significantly higher in obese patients.

CONCLUSION

Compared to healthy subjects potential ECG repolarization predictors were significantly increased in extremely obese patients.

A Comparative Study of Receptor-Targeted Magnetosome and HSA-Coated Iron Oxide Nanoparticles as MRI Contrast-Enhancing Agent in Animal Cancer Model

Magnetosomes are specialized organelles arranged in intracellular chains in magnetotactic bacteria. The superparamagnetic property of these magnetite crystals provides potential applications as contrast-enhancing agents for magnetic resonance imaging. In this study, we compared two different nanoparticles that are bacterial magnetosome and HSA-coated iron oxide nanoparticles for targeting breast cancer. Both magnetosomes and HSA-coated iron oxide nanoparticles were chemically conjugated to fluorescent-labeled anti-EGFR antibodies. Antibody-conjugated nanoparticles were able to bind the MDA-MB-231 cell line, as assessed by flow cytometry. To compare the cytotoxic effect of nanoparticles, MTT assay was used, and according to the results, HSA-coated iron oxide nanoparticles were less cytotoxic to breast cancer cells than magnetosomes. Magnetosomes were bound with higher rate to breast cancer cells than HSA-coated iron oxide nanoparticles. While 250 μg/ml of magnetosomes was bound 92 ± 0.2%, 250 μg/ml of HSA-coated iron oxide nanoparticles was bound with a rate of 65 ± 5%. In vivo efficiencies of these nanoparticles on breast cancer generated in nude mice were assessed by MRI imaging. Anti-EGFR-modified nanoparticles provide higher resolution images than unmodified nanoparticles. Also, magnetosome with anti-EGFR produced darker image of the tumor tissue in T2-weighted MRI than HSA-coated iron oxide nanoparticles with anti-EGFR. In vivo MR imaging in a mouse breast cancer model shows effective intratumoral distribution of both nanoparticles in the tumor tissue. However, magnetosome demonstrated higher distribution than HSA-coated iron oxide nanoparticles according to fluorescence microscopy evaluation. According to the results of in vitro and in vivo study results, magnetosomes are promising for targeting and therapy applications of the breast cancer cells.

Antisense oligonucleotide delivery to cancer cell lines for the treatment of different cancer types

Amphiphilic poly(3-hydroxylalkanoate) (PHA) copolymers find interesting applications in drug delivery. The aim of this study was to prepare nucleic acid adsorbed on (PHB-b-PEG-NH₂) nanoparticle platform for gene delivery. For this purpose, PHB-b-PEG-NH₂ block copolymers were synthesized via transesterification reactions. The copolymers obtained were characterized by Proton Nuclear Magnetic Resonance (¹H-NMR), Fourier Transform Infrared Spectrometer (FTIR), Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) techniques. The cytotoxic, apoptotic and necrotic effects of these nanoparticles in the MDA 231 human breast cancer cell, the A549 human lung cancer cell and the L929 fibroblast cell lines were also investigated.

Aligned bacterial PHBV nanofibrous conduit for peripheral nerve regeneration

The conventional method of peripheral nerve gap treatment is autografting. This method is limited. In this study, an aligned nanofibrous graft was formed using microbial polyester, Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). The regenerative effect of the graft was compared with that of autografting in vivo. To determine the regenerative effect, rats were assessed with sciatic nerve functional index, electromyographic evaluation, and histological evaluation. Results found in this study include PHBV grafts stimulated progressive nerve regeneration, although regeneration was not comparable with that of autografting. We conclude that the study results were promising for aligned bacterial polymeric grafts for peripheral nerve regeneration.

Titania nanotubes with adjustable dimensions for drug reservoir sites and enhanced cell adhesion

This study aims to generate a bactericidal agent releasing surface via nanotube layer on titanium metal and to investigate how aspect ratio of nanotubes affects drug elution time and cell proliferation. Titania nanotube layers were generated on metal surfaces by anodic oxidation at various voltage and time parameters. Gentamicin loading was carried out via simple pipetting and the samples were tested against S. aureus for the efficacy of the applied modification. Drug releasing time and cell proliferation were also tested in vitro. Titania nanotube layers with varying diameters and lengths were prepared after anodization and anodizing duration was found as the most effective parameter for amount of loaded drug and drug releasing time. Drug elution lasted up to 4 days after anodizing for 80 min of the samples, whereas release completed in 24 h when the samples were anodized for 20 min. All processed samples had bactericidal properties against S. aureus organism except unmodified titanium, which was also subjected to drug incorporation step. The anodization also enhanced water wettability and cell adhesion results. Anodic oxidation is an effective surface modification to enhance tissue-implant interactions and also resultant titania layer can act as a drug reservoir for the release of bactericidal agents. The use of implants as local drug eluting devices is promising but further in vivo testing is required.

Preparation and characterization of magnetically responsive bacterial polyester based nanospheres for cancer therapy

Polyhydroxyalkanoates (PHA) are natural, thermoplastic polyesters and due to their biocompatible and biodegradable properties they are good alternatives for the production of scaffolds for engineered tissues or nanoparticles for drug delivery. As a member of polyhydroxyalkanoate family, polyhydroxybutyrates (PHB) have been widely used as a biomaterial for in vitro and in vivo studies since their mechanical properties are very similar to conventional plastics. By using multi-emulsion technique, iron oxide particles were coated with polyhydroxybutyrate (PHB) polymer synthesized from Alcaligenes eutrophus bacteria and the magnetic carrier system was prepared accordingly. The bare nanoparticles and magnetic nanoparticles were morphologically, structurally and magnetically characterized by using Scanning electron microscope (SEM) and Atomic force microscope (AFM); Fourier Transform Infrared Spectrometry (FTIR), and Electron Spin Resonance (ESR) and Vibrating Sample Magnetometer (VSM) techniques, respectively. Particle size of PHB nanoparticles was determined by Zeta Sizer. It was found that the smallest particles were in the range of 239.43 +/- 5.25 nm in diameter. Concanavalin-A (Con-A) was used for targeting the cancer cells while etoposide was used as drug. Con-A and etoposide were loaded onto the particles. Release studies of etoposide were evaluated and the system was optimized for the further in vivo applications. Finally different formulation magnetic PHB nanoparticles cytotoxicity were evaluated in cell culture studies and used HeLa cell line (cervical cancer cells) as a cancer cells and L929 cells (mouse fibroblast cells) as a non-cancer cell line.

Recognition and management of overweight and obese children: a questionnaire survey of general practitioners and parents in England

AIMS

To (i) compare the views of general practitioners (GPs) and parents about the causes, consequences and management of childhood overweight/obesity; and (ii) explore the extent to which they can identify overweight/obesity in children.

METHODS

A questionnaire was mailed to all GPs in one Primary Care Trust and all parents in one primary school in southern England, 2008. Information was gathered on socio-demographic background, views about causes, consequences and management of childhood overweight/obesity; judgements about the weight status of 14 images of children (seven boys, seven girls) in the Children's Body Image Scale (CBIS). Comparisons were made between GP and parents' responses using unpaired bivariate tests.

RESULTS

The response rate was 33%. Differences exist between the views of GPs and parents about childhood weight management: 86.4% of parents felt GPs should be involved, compared to 73.3% of GPs (P < 0.001). Parents thought GPs should be more proactive than the GPs stated they would be. GPs were significantly more likely than parents to see a role for school nurses and dieticians. One third of respondents thought GPs lacked expertise in child weight management. Most GPs and parents correctly identified obese children from the images, but inaccuracies occurred at category margins.

CONCLUSIONS

Childhood overweight/obesity is a serious public health concern, and primary care has a role to play in tackling it. GPs in England need more training in childhood overweight/obesity management. Their role needs to be clarified in the context of multiagency approaches.

Mutation analysis of the Vangl2 coding region revealed no common cause for Tetralogy of Fallot

Vangl2 (Van Gogh-like 2) protein acts via non-canonical Wnt signalling to regulate polarized cell movements during development of the proximal outflow tract in vertebrate embryos. Recently, it has been shown that mutations of the Vangl2 gene cause aortic arch defects that are characteristic of the loop-tail (Lp) mouse and they have also became a strong candidate for causing congenital outflow tract defects in humans. Thus, in this study Tetralogy of Fallot (ToF), which comprises a group of syndromes that constitutes the most frequent cause of congenital cardiac outflow abnormalities in humans, was analysed for mutations within all coding regions of the Vangl2 gene. Based on direct sequencing data from a combination of 20 patients with ToF and 22 healthy people, three polymorphisms have been identified in exon 6 and exon 7 which do not change the amino acid sequence. It was concluded, therefore, that there is no specific mutation responsible for the ToF phenotype in the Vangl2 gene.

Association of T102C polymorphism of the 5-HT2A receptor gene with psychiatric status in fibromyalgia syndrome

Serotonin (5-HT) is a key neurotransmitter in the central nervous system. It is suggested that serotonergic dysfunction may be involved in the pathophysiology of fibromyalgia syndrome (FS). In this study, we aimed to investigate T102C polymorphism of the 5-HT2A receptor gene in FS. Fifty-eight patients with FS and 58 unrelated healthy volunteer controls were included in the study. In both groups, the C/C, C/T, and T/T genotypes of the 5-HT gene were represented in 31% (22.4% in controls), 50% (53.4%), and 19% (24.1%), respectively. The 5-HT2A receptor gene polymorphism results were not significantly different between patients and controls (chi squared test, P>0.05). There was a significant correlation between patients with the T/T genotype and the subgroup according to the SCL-90-R test, (analysis of variance, P<0.05). We also saw that patients with the T/T genotype had the lowest pain threshold. CONCLUSION. T102C polymorphism of the 5-HT2A receptor gene is not associated with the etiology of FS. Our results also indicate that the T/T genotype may be responsible for psychiatric symptoms of FS.

Possible association of temporomandibular joint pain and dysfunction with a polymorphism in the serotonin transporter gene

The purpose of this study was to evaluate the relationship between temporomandibular joint pain and dysfunction and serotonin transporter (5-HTT) gene polymorphism. Forty-eight patients with temporomandibular joint pain and 111 healthy control subjects were examined. The results for the patients and control subjects were not significantly different (P >.05). The analysis of genotype distribution (homozygous for STin 2.10 genotypes of the variable-number tandem-repeat polymorphism) showed significant differences between the patients and control subjects (P =.003). ST 2.10 allele was more frequent in the patients with temporomandibular joint pain and dysfunction. In the control group, however, STin 2.12/12 genotype was significantly higher (P =.017). In the patients who were homozygous or heterozygous for variable-number tandem-repeat variants of 5-HTT STin 2.12 copies, the average scores of somatization and anger were significantly higher than those who were homozygous for STin 2.10 variant (P <.05). The patients who were homozygous for STin 2.10 genotype were also homozygous for "L" genotype (P =.019). However, this was not the condition in the control subjects. This study does not provide evidence to support the involvement of 5-HTT gene-linked polymorphic region in temporomandibular joint pain and dysfunction. Our findings indicated that only the presence of the homozygous STin 2.10 genotype of variable-number tandem-repeat is likely to play a substantial role in the genetic predisposition to temporomandibular joint pain and dysfunction and that the STin 2.12/12 genotype may have a protective role against temporomandibular joint pain and dysfunction.

Processing of tetanus and botulinum A neurotoxins in isolated chromaffin cells

Tetanus and botulinum A neurotoxins were introduced into the cytosol of chromaffin cells by means of an electric field in which the plasma membrane is forced to form pores of approximately 1 micron at the sites facing the electrodes. As demonstrated by electron microscopy, both [125I] and gold-labelled tetanus toxin (TeTx) diffuse through these transient openings. Dichain-TeTx, with its light chain linked to the heavy chain by means of a disulfide bond, causes the block of exocytosis to develop more slowly than does the purified light chain. The disulfide bonds, which in both toxins hold the subunits together, were cleaved by the intrinsic thioredoxin-reductase system. Single chain TeTx, in which the heavy and light chains are interconnected by an additional peptide bond, was far less effective than dichain-TeTx at blocking exocytosis, which indicates that proteolysis is the rate-limiting step. The toxins were degraded further to low-molecular weight fragments which, together with intact toxins and subunits, were released by the cells. The intracellular half-life of [125I] dichain-TeTx was approximately three days. The number of light-chain molecules required to maintain exocytosis block in a single cell, as calculated by two different methods, was less than 10. The long duration of tetanus poisoning may result from the persistence of intracellular toxin due to scarcity of free cytosolic proteases. This may also hold for the slow recovery from botulism.