Gold Nanoparticles in Parkinson's Disease Therapy: A Focus on Plant-Based Green Synthesis.

Parkinson's disease (PD) is a progressive neurodegenerative disease that affects approximately 1% of people over the age of 60 and 5% of those over the age of 85. Current drugs for Parkinson's disease mainly affect the symptoms and cannot stop its progression. Nanotechnology provides a solution to address some challenges in therapy, such as overcoming the blood-brain barrier (BBB), adverse pharmacokinetics, and the limited bioavailability of therapeutics. The reformulation of drugs into nanoparticles (NPs) can improve their biodistribution, protect them from degradation, reduce the required dose, and ensure target accumulation. Furthermore, appropriately designed nanoparticles enable the combination of diagnosis and therapy with a single nanoagent. In recent years, gold nanoparticles (AuNPs) have been studied with increasing interest due to their intrinsic nanozyme activity. They can mimic the action of superoxide dismutase, catalase, and peroxidase. The use of 13-nm gold nanoparticles (CNM-Au8®) in bicarbonate solution is being studied as a potential treatment for Parkinson's disease and other neurological illnesses. CNM-Au8® improves remyelination and motor functions in experimental animals. Among the many techniques for nanoparticle synthesis, green synthesis is increasingly used due to its simplicity and therapeutic potential. Green synthesis relies on natural and environmentally friendly materials, such as plant extracts, to reduce metal ions and form nanoparticles. Moreover, the presence of bioactive plant compounds on their surface increases the therapeutic potential of these nanoparticles. The present article reviews the possibilities of nanoparticles obtained by green synthesis to combine the therapeutic effects of plant components with gold.

Computational, In Vitro, and In Vivo Models for Nose-to-Brain Drug Delivery Studies.

Direct nose-to-brain drug delivery offers the opportunity to treat central nervous system disorders more effectively due to the possibility of drug molecules reaching the brain without passing through the blood-brain barrier. Such a delivery route allows the desired anatomic site to be reached while ensuring drug effectiveness, minimizing side effects, and limiting drug losses and degradation. However, the absorption of intranasally administered entities is a complex process that considerably depends on the interplay between the characteristics of the drug delivery systems and the nasal mucosa. Various preclinical models (in silico, in vitro, ex vivo, and in vivo) are used to study the transport of drugs after intranasal administration. The present review article attempts to summarize the different computational and experimental models used so far to investigate the direct delivery of therapeutic agents or colloidal carriers from the nasal cavity to the brain tissue. Moreover, it provides a critical evaluation of the data available from different studies and identifies the advantages and disadvantages of each model.

Temperature limits during irradiation in laser-assisted treatment of peri-implantitis - labo-ratory research.

INTRODUCTION: Peri-implantitis is a relatively new and difficult disease that is becoming more common. Of the different therapeutic options to manage this condition, lasers show certain advantages over other therapeutic alternatives because of their antibacterial potential. AIM: The aim of the present study was to investigate the temperature rise of implant surfaces, soft tissues, and bone during irradiation with diode, CO2, and Er:YAG lasers. MATERIALS AND METHODS: Ten implants inserted in biological models were irradiated with three laser systems with different parameters: a diode laser (980 nm) with power levels of 0.75 W and 1.6 W; a CO2 laser (10600 nm) with power levels of 252 W and 241 W; and an Er:YAG laser (2940 nm) with power levels of 1.5 W, 6.8 W, and 7.5 W. The temperature rise was measured using a specially designed thermal probe (type K thermocouple) with accuracy of ±0.1°C over the range from 20°C to 80°C. The temperature was measured at 5 points - in the implant body, in the mucosa, in the middle part of the implant, in the implant apex, and in the bone around the implant apex. Measurements were obtained at 1 minute working interval. RESULTS: Diode and CO2 lasers with both parameters used increased significantly the temperature of more than 46°C, whereas the temperature in the Er:YAG laser group was less than 30°C. There was a statistically significant difference between diode, CO2, and Er:YAG lasers in favor of the erbium laser. CONCLUSIONS: The Er:YAG laser demonstrates the best thermal properties during irradiation of the implant surface. The three working modes tested - 1.5 W, 6.8 W, and 7.5 W - provide safe intervention on both the soft and bone tissues of the implant interface and on the implant itself.

Casein-Based Nanoparticles: A Potential Tool for the Delivery of Daunorubicin in Acute Lymphocytic Leukemia.

The aim of this study was to develop casein-based nanoscale carriers as a potential delivery system for daunorubicin, as a pH-responsive targeting tool for acute lymphocytic leukemia. A coacervation technique followed by nano spray-drying was used for the preparation of drug-loaded casein nanoparticles. Four batches of drug-loaded formulations were developed at varied drug-polymer ratios using a simple coacervation technique followed by spray-drying. They were further characterized using scanning electron microscopy, dynamic light scattering, FTIR spectroscopy, XRD diffractometry, and differential scanning calorimetry. Drug release was investigated in different media (pH 5 and 7.4). The cytotoxicity of the daunorubicin-loaded nanoparticles was compared to that of the pure drug. The influence of the polymer-to-drug ratio on the nanoparticles' properties such as their particle size, surface morphology, production yield, drug loading, entrapment efficiency, and drug release behavior was studied. Furthermore, the cytotoxicity of the drug-loaded nanoparticles was investigated confirming their potential as carriers for daunorubicin delivery.

SEM analysis of the endodontic cavity wall after removal of restorative materials used as temporary restoration.

AIM: The aim of the present in vitro study was to analyze the endodontic cavity walls for presence of remnants of conventional glass ionomer cement and flowable light cure composite used as temporary restorative materials of endodontically treated teeth. The dentine surface of the access cavity was observed with scanning electron microscopy after the final removal of the temporary restoration using high-speed turbine and diamond bur or ultrasonic device and diamond tip.

Alzheimer's disease: the hypotheses, known and unknown connections between UV-radiation, mtDNA haplotypes and life span - a review.

Alzheimer's disease (AD) is the most common neurodegenerative disease with controversial etiology. One theory claims that AD is due to brain aging affecting mainly the functions of mitochondria, therefore, the factors leading to mitochondrial ageing should lead to the development of Alzheimer's disease. Another theory is that different mitochondrial DNA haplogroups can be predisposition for the onset of the condition. Here we focused on the possible connection between AD and UV radiation using the data on the monthly UV index in Europe, its correlation with mortality rate due to AD and mitochondrial DNA haplogroups distribution. If a link between the two theories is proved, it will mean that UV radiation is a risk factor not only for skin cancer but also for a large group of neurodegenerative diseases amongst which is the Alzheimer's disease.

The Photobiomodulation of MAO-A Affects the Contractile Activity of Smooth Muscle Gastric Tissues.

Nowadays, the utilized electromagnetic radiation (ER) in modalities such as photobiomodulation (PBM) finds broader applications in medical practice due to the promising results suggested by numerous reports. To date, the published data do not allow for the in-depth elucidation of the molecular mechanisms through which ER impacts the human organism. Furthermore, there is a total lack of evidence justifying the relation between the enzymatic activity of monoamine oxidase A (MAO-A) and the effect of 5-hydroxytryptamine (5-HT) on the spontaneous contractile activity of smooth muscle gastric tissues exposed to various light sources. We found that exposure of these tissues to lamps, emitting light with wavelengths of 254 nm and 350 nm, lasers, emitting light with 532 nm and 808 nm, and light-emitting diodes (LEDs) with ER at a wavelength of 660 nm, increased the 5-HT effect on the contractility. On the other hand, LEDs at 365 nm and 470 nm reduced it. The analysis of MAO-A enzymatic activity after exposure to the employed light emitters endorsed these findings. Furthermore, MAOA gene expression studies confirmed the possibility of its optogenetic regulation. Therefore, we concluded that the utilized emitters could alternate the functions of significant neuromediators by modulating the activity and gene transcription levels of enzymes that degrade them. Our investigations will help to disclose the selective conditions upon which PBM can effectively treat gastrointestinal and neurological disorders.

Amination of Graphene Oxide Leads to Increased Cytotoxicity in Hepatocellular Carcinoma Cells.

Clinically, there is an urgent need to identify new therapeutic strategies for selectively treating cancer cells. One of the directions in this research is the development of biocompatible therapeutics that selectively target cancer cells. Here, we show that novel aminated graphene oxide (haGO-NH2) nanoparticles demonstrate increased toxicity towards human hepatocellular cancer cells compared to pristine graphene oxide(GO). The applied novel strategy for amination leads to a decrease in the size of haGO-NH2 and their zeta potential, thus, assuring easier penetration through the cell membrane. After characterization of the biological activities of pristine and aminated GO, we have demonstrated strong cytotoxicity of haGO-NH2 toward hepatic cancer cells - HepG2 cell line, in a dose-dependent manner. We have presented evidence that the cytotoxic effects of haGO-NH2 on hepatic cancer cells were due to cell membrane damage, mitochondrial dysfunction and increased reactive oxygen species (ROS) production. Intrinsically, our current study provides new rationale for exploiting aminated graphene oxide as an anticancer therapeutic.

Etifoxine does not impair muscle tone and motor function in rats as assessed by in vivo and in vitro methods.

The purpose of our study is to evaluate the effects of the translocator protein (TSPO) ligand etifoxine on muscle tone and locomotor activity. In addition, the mechanism of action of etifoxine on the presynaptic membrane and neuromuscular junction is investigated. These effects of etifoxine were examined employing the following methods: 1) in vivo experiments using bar holding test and activity cage test, and 2) comparative in vitro studies with nifedipine on indirectly-elicited twitches of striated abdominal muscle preparations. Etifoxine in doses 50 mg/kg and 100 mg/kg i.p. does not produce any significant changes in locomotor activity and muscle tone of intact rats. Nifedipine (10-5 М) induces a significant decrease in the muscle force of striated muscle preparations. Etifoxine (10-8-10-4 М) has no significant effect on indirectly-elicited twitch tension. Results show that the TSPO ligand etifoxine has no myorelaxant effect. The activation of TSPO is not associated with a reduction in muscle tone and motor impairment. Etifoxine does not affect the presynaptic membrane and its influence on L-type Ca2+-channels is insignificant. Etifoxine does not act as a competitive antagonist of acetylcholine and does not impair the impulse transmission in the neuromuscular junction.

Linker histones and chromatin remodelling complexes maintain genome stability and control cellular ageing.

Linker histones are major players in chromatin organization and per se are essential players in genome homeostasis. As the fifth class of histone proteins the linker histones not only interact with DNA and core histones but also with other chromatin proteins. These interactions prove to be essential for the higher levels of chromatin organization like chromatin loops, transcription factories and chromosome territories. Our recent results have proved that Saccharomyces cerevisiae linker histone - Hho1p, physically interacts with the actin-related protein 4 (Arp4) and that the abrogation of this interaction through the deletion of the gene for the linker histone in arp4 mutant cells leads to global changes in chromatin compaction. Here, we show that the healthy interaction between the yeast linker histone and Arp4p is critical for maintaining genome stability and for controlling cellular sensitivity to different types of stress. The abolished interaction between the linker histone and Arp4p leads the mutant yeast cells to premature ageing phenotypes. Cells die young and are more sensitive to stress. These results unambiguously prove the role of linker histones and chromatin remodelling in ageing by their cooperation in pertaining higher-order chromatin compaction and thus maintaining genome stability.

Effects of Low Level Laser Therapy on Erosive-atrophic Oral Lichen Planus.

BACKGROUND: The erosive-atrophic form of oral lichen planus (OLP) is associated with severe pain and burning sensation and is often unresponsive to treatment. Topical corticosteroids are considered as a medication of first choice but they can produce adverse effects. Therefore, new therapeutic approaches are required. AIM: The aim of this study was to investigate the effectiveness of biomodulation with diode laser in patients presenting with long-standing erosive-atrophic OLP. MATERIALS AND METHODS: Twelve patients, clinically and histologically diagnosed with OLP, participated in this study. The level of pain and the clinical scores of total 59 lesions were recorded before treatment using visual analog scale and Thongprasom sign scoring system respectively. All patients received low level laser therapy (LLLT) with diode laser (810 nm) with parameters (0.5 W, 30 s, 1.2 J/cm2) three times weekly for a month. The response rate was assessed according to the decrease in pain and sign scores. Treatment efficacy index was calculated. RESULTS: There was a significant reduction in pain after LLLT (p<0.0001). Improvement in clinical signs was achieved in 59.3% of the lesions. At the end of the treatment 5.1% of the lesions exhibited score 5; 6.8% - score 4, 11.9% of the lesions were scored 3 and 8.5% and 30.5% showed score 2 and score 1, respectively. Complete resolution was revealed in 37.3% of the lesions. All patients experienced some degree of improvement. Most of the cases showed moderate recovery. CONCLUSION: The present results indicate that LLLT is an effective and harmless modality for management of erosive-atrophic OLP.

Oral Lichen Planus - Known and Unknown: a Review.

Lichen planus is a chronic mucocutaneous inflammatory disease aff ecting 1-2% of the general population with maximum prevalence of the disease in women above the age of 40. Its aetiology remains unclear and the pathogenesis is still the object of much speculation. It is considered to be an autoimmune disorder mediated mainly by the T-lymphocytes. The present paper presents the most well-known external agents (viruses in particular), internal agents like stress, and the heat shock protein thought to be trigger factors and describes the action of diff erent cells and proteins associated with the development of that disease. Diagnosis is based on clinical and histopathologic evidence; direct and indirect immunofluorescence techniques can also be of use. Despite the wide variety of therapeutic modalities, treatment outcomes are often insufficient. Currently, topical corticosteroids are widely accepted as a standard therapy, but also retinoids, calcineurin inhibitors and other immunosuppressants can be administered. Because of the aspect relevant to these drugs, priority is given to alternative harmless methods such as LLLT and PDLT. There is an ongoing controversy in the literature about the possible premalignant character of oral lichen planus, however, periodic followup is recommended.

In vivo investigation of antihyperalgesic and antinociceptive effects of peat formulations.

The aim of this study is to evaluate the antihyperalgesic and antinociceptive effects of two formulations containing peat water extracts using a model of carrageenan-induced hyperalgesia, combined with a test with a mechanical stimulus, and a hot plate test. Rats were divided into seven groups (n = 6) and received local treatment with two peat formulations and two diclofenac formulations dissolved in carbopol gel and Wolff® basis creme, respectively. Carbopol gel, Wolff® basis creme and 0.9 % NaCl without tested substances were used as controls. Both peat formulations exerted an unambiguous antihyperalgesic effect 60 minutes after the treatment. In the hot plate test, the rats treated with the Wolff® basis creme peat formulation showed a tendency to prolonged latency on the first hour. The results could be explained by partial activation of peripheral α2-adrenoceptors and the possible COX-2 suppressive activity.

Retigabine diminishes the effects of acetylcholine, adrenaline and adrenergic agonists on the spontaneous activity of guinea pig smooth muscle strips in vitro.

PURPOSE: The aim of this study is to evaluate the effect of retigabine on the smooth muscle response to acetylcholine, adrenaline, α-and ß-adrenoceptor agonists. METHODS: We studied the change in the spontaneous smooth muscle contraction of guinea pig gastric corpus strips before and after 20-min treatment with 2µM retigabine. We also evaluated the effect of retigabine on the smooth muscle response to 10µM acetylcholine, 1 and 10µM adrenaline, 1µM methoxamine, 0.1µM p-iodoclonidine and 10µM isoproterenol. RESULTS: We observed a significant reduction in the effects of all studied mediators and agonists when they were added to organ baths in the presence of retigabine. Retigabine diminished the effect of acetylcholine on the spontaneous smooth muscle activity. The effect was fully antagonized by XE-991 (Kv7 channel blocker), which supports our hypothesis about the role of KCNQ channels in the registered changes. The increase in the contraction force after adding of 1µM adrenaline, methoxamine, and 0.1µM p-iodoclonidine was also significantly smaller in presence of retigabine. However, comparing the effect of 10µM adrenaline on the contractility before and after treatment with retigabine, we observed increased contractility when retigabine was present in the organ baths. CONCLUSION: A possible explanation for the observed diminished effects of mediators and receptor agonists is that the effect of retigabine on smooth muscle contractility is complex. The membrane hyperpolarization, the interaction between Kv7 channels and adrenoceptors, and the influence on signaling pathways may contribute to the summary smooth muscle response.

In Vitro Study of Temperature Changes in Pulp Chamber During Root Planing Procedure Using Er:YAG Laser.

AIM: To assess temperature changes at specified time intervals during Er:YAG laser scaling and root planing of surfaces with dental calculus. MATERIALS AND METHODS: Fifteen single-rooted teeth with advanced periodontal disease were extracted and fixed in a cylinder thermostat filled with distilled water at constant temperature (35.5°C). A specially designed thermal probe (type K thermocouple) accurate to ±0.1°C over the range from 20°C to 80°C was fitted into the pulp chamber of tooth sample. Scaling and root planing of the mesial and distal root surfaces was performed using an Er:YAG laser (Lite Touch, Syneron Dental, Israel) with a wavelength of 2940 nm, provided with a chisel tip, and at the following settings: output energy 100 mJ and 50 Hz, duration of irradiation - 40 sec, the tip in contact mode oblique to the root surface at an angle of approximately 10-15 degrees and water spray level 5-6. The temperature inside the pulp chamber was measured every 10 sec. RESULTS: The temperature in the pulp chamber taken every 10 seconds and compared with the temperature of 35.5°C at baseline decreased by 1.6°C, 2.4°C, 2.5°C, and 2.5°C for the first, second, third and fourth measurement, respectively. These changes did not reach statistical significance. CONCLUSION: The Er:YAG laser does not increase the temperature inside the pulp chamber. The assessed changes do not depend on the duration of irradiation which was kept within 40 seconds. Therefore, this treatment modality causes no thermal damage to the pulp under the above defined conditions and can be considered safe.

Random, double- and single-strand DNA breaks can be differentiated in the method of Comet assay by the shape of the comet image.

Comet assay is an invaluable tool in DNA research. It is widely used to detect DNA damage as an indicator of exposure to genotoxic stress. A canonical set of parameters and specialized software programs exist for Comet assay data quantification and analysis. None of them so far has proven its potential to employ a computer-based algorithm for assessment of the shape of the comet as an indicator of the exact mechanism by which the studied genotoxins cut in the molecule of DNA. Here, we present 14 unique measurements of the comet image based on the comet morphology. Their mathematical derivation and statistical analysis allowed precise description of the shape of the comet image which in turn discriminated the cause of genotoxic stress. This algorithm led to the development of the "CometShape" software which allowed easy discrimination among different genotoxins depending on the type of DNA damage they induce.

Formulation and performance evaluation of betahistine dihydrochloride microspheres as sustained release systems.

UNLABELLED: Betahistine dihydrochloride is a histamine-like drug widely used in relieving the symptoms associated with Ménière's syndrome. Pharmacokinetic studies of betahistine have demonstrated that it has a short plasma half-life of 3-4 hours. In such cases frequent administration of the drug is required in order to keep plasma concentration within the therapeutic range. However, this may lead to noncompliance and aggravate patients' comfort. An advanced approach for achieving sustained release of drugs is their incorporation in microparticulate carriers. AIM: To design a sustained release microsphere formulation of betahistine providing reduced dose frequency and lower risk of side effects occurrence. MATERIALS AND METHODS: Betahistine-loaded chitosan microspheres were obtained via W/O emulsion solvent evaporation technique and were characterized for particle size, drug loading and entrapment efficiency. Drug release into phosphate buffer saline pH 7.4 was performed and dissolution profiles of the formulations were obtained. To study the mechanism of drug release from the microspheres the dissolution data was fitted to various mathematic models. RESULTS: Betahistine-loaded microspheres were produced with a high drug loading and entrapment efficiency. The microcarriers were spherical in shape with mean particle size of 3.82 µm to 7.69 µm. Betahistine release studies from the microspheres showed similar and slightly increasing dissolution profiles. The drug release proceeded in a controlled manner following Fickian diffusion. CONCLUSION: The obtained results suggest that betahistine-loaded chitosan microspheres prepared by solvent evaporation method are capable of sustained release of drugs and therefore can be used as drug delivery systems in the treatment of Ménière's syndrome.

Production of metabolites with antioxidant and emulsifying properties by antarctic strain Sporobolomyces salmonicolor AL1.

The Sporobolomyces salmonicolor AL(1) Antarctic strain was cultivated and two bioproducts were obtained: exopolysaccharide and biomass. The biologically active substances ergosterol, torularhodin, torulene, ß-carotene and CoQ(10) were extracted from the biomass and were quantified as follows: ergosterol 5.2 ± 0.2 mg/g, torularhodin 458.3 ± 24.5 µg/g, torulene 273.7 ± 14.5 µg/g, ß-carotene 129.2 ± 7.3 µg/g and coenzyme Q(10) (CoQ(10)) 236.1 ± 12.1 µg/g. Their antioxidant activity was estimated according to the cathode voltammetry method. The most pronounced antioxidant activity (according to trolox) was exhibited by ß-carotene 3.78, followed by CoQ(10) 3.60, both of them being the main contributors to the total extract activity of 3.19. The biologically active metabolites in combination with exoglucomannan as emulsifier were used for the creation of model emulsion systems characterised by great stability. The absorption of UVA rays by the model emulsions was studied.

Synthesis and contractile activity of substituted 1,2,3,4-tetrahydroisoquinolines.

A series of different 1-monosubstituted and 1,1-disubstituted 1,2,3,4-tetrahydro-isoquinolines was synthesized in high yields from different ketoamides. We have developed a convenient method for the synthesis of disubstituted derivatives by interaction of ketoamides with organomagnesium compounds, followed by cyclization in the presence of catalytic amounts of p-toluenesulfonic acid (PTSA). A number of substituents at the C-1 in the isoquinoline skeleton were introduced varying either carboxylic acid or organomagnesium compound. Some of the obtained 1,1-dialkyl-1,2,3,4-tetrahydro-isoquinolines possess contractile activity against guinea pig's gastric smooth muscle preparations.

Synthesis of coenzyme Q10 and beta-carotene by yeasts isolated from antarctic soil and lichen in response to ultraviolet and visible radiations.

The effect of different doses of visible (Vis), ultraviolet-capital A, Cyrillic (UVA), and mixed light (UVA + Vis) upon coenzyme Q(10) (CoQ(10)) and beta-carotene synthesis and biomass yield by the Sporobolomyces salmonicolor AL(1), Cryptococcus albidus AS(55), Cryptococcus laurentii AS(56), and C. laurentii AS(58) strains isolated from Antarctic samples was investigated. The beta-carotene concentration in the red strain biomass increased by 52% under irradiation with 11 J/cm(2) Vis, and the CoQ(10) concentration rose by 37% in relation to the control quantity obtained through dark cultivation. Under irradiation with 6 J/cm(2) UVA, the S. salmonicolor AL(1) strain synthesized 15% more beta-carotene; C. albidus AS(55), 22%; C. laurentii AS(56), 44%; and C. laurentii AS(58), 35% in relation to the control quantity. Irradiation with a low UVcapital A, Cyrillic + Vis dose significantly stimulated beta-carotene biosynthesis by the strains of the Cryptococcus genus (87%, 138%, and 100%), whereas S. salmonicolor AL(1) increased the beta-carotene content to a smaller degree (55%). Higher doses of all three irradiation types inhibited beta-carotene accumulation. Vis suppressed CoQ(10) biosynthesis in the Cryptococcus strains, whereas UVcapital A, Cyrillic and UVcapital A, Cyrillic + Vis inhibited it in all four strains. The S. salmonicolor AL(1) strain pre-treated with 0.02 J/cm(2) UVA synthesized twice as much CoQ(10) and beta-carotene when cultivated in the presence of Vis light in an 11-J/cm(2) dose.