Reduction in Pathogenic Biofilms by the Photoactive Composite of Bacterial Cellulose and Nanochitosan Dots under Blue and Green Light

In this study, nanochitosan dots (ChiDs) were synthesized using gamma rays and encapsulated in bacterial cellulose (BC) polymer matrix for antibiofilm potential in photodynamic therapy. The composites were analyzed for structural changes using SEM, AFM, FTIR, XRD, EPR, and porosity measurements. Additionally, ChiD release was assessed. The results showed that the chemical composition remained unaltered, but ChiD agglomerates embedded in BC changed shape (1.5–2.5 µm). Bacterial cellulose fibers became deformed and interconnected, with increased surface roughness and porosity and decreased crystallinity. No singlet oxygen formation was observed, and the total amount of released ChiD was up to 16.10%. Antibiofilm activity was higher under green light, with reductions ranging from 48 to 57% under blue light and 78 to 85% under green light. Methicillin-resistant Staphylococcus aureus was the most sensitive strain. The new photoactive composite hydrogels show promising potential for combating biofilm-related infections

The role of a pharmacist in pharmacovigilance system

Introduction: Although they represent an important mediator between patients and National Pharmacovigilance Centre, pharmacists still don't participate enough in system of reporting adverse drug reactions (ADR). By reporting ADR both quality of therapy and quality of patient's life are improving, and pharmaceutical industry is also encouraged to invent and produce new formulations which will be better beared and whose use will significantly improve risk-benefi t ratio. Aim: The aim of this work is that by collecting information about ADRs, based on direct contact of a pharmacist and patients, explain and improve the role of a pharmacist in pharmacovigilance system. Subjects and Methods: Information about adverse reactions were being collected in three private pharmacies in Inđija and in one private pharmacy in Sombor. In period from 20.12.2017.-10.01.2018. pharmacists collected data about adverse reactions of medicines. In period from 11.01.-01.02.2018. patients were additionally informed about unexpected and adverse drug reactions. The standard form for reporting an adverse reaction, which was taken from the site of Medicines and Medical Devices Agency of Serbia (ALIMS), was fi lled for each reported case and sent to National Pharmacovigilance Center (NPC). Suspect drugs were classified in categories according to Anatomical-Therapeutic-Chemical classification (ATC). Results: In first period, there were 19 reported reactions. After additional information given to patients, there were 33 reported adverse reactions. The most numerous adverse drug reactions were reported for the group of cardiovascular drugs (32.7%), the group of anti-infective drugs with systemic effects (15.4%) and for group of drugs which affect nervous system (13.5%). After analyzing reported reactions, according to NPC all of reactions were expected (52), but 3 of them fulfilled criteria of seriousness. Conclusions: Thanks to additional information and direct communication between a pharmacist and patients, reporting unexpected and adverse drug reactions is significantly improving

Influence of immediate release tablet formulation on dissolution profile of paracetamol

Introduction: Paracetamol is analgesic and antipyretic, which is usually in the form of an immediate release tablet formulations. Therapeutic effects in terms of the speed and intensity of the analgesic effect is dependent on speed of liberation from formulation. Aim: The aim of this work was to determine and compare dissolution profiles of 4 paracetamol immediate release tablet formulations and to determine influence of excipients on kinetic of paracetamol dissolution. Materials and Methods: Dissolution profiles of paracetamol tablets were determined using method with paddles and phosphate buffer pH 6.8 as a medium. Release of paracetamol was followed 60 minutes (using 6 time points). Concentration of paracetamol was measured using UV/Vis spectrophotometric method (243 nm). Dissolution profiles were compared using model-independent method (difference factor and similarity factor), statistic method (ANOVA-based method and pair Student's T-test, p<0.05) and model dependent methods (to determinate the release kinetics of paracetamol). Results: All formulations in the first 45 minutes liberated more than 85 % of the labled content. Formulation D, which contained superdesintegrator, released 90% of the content in the first 5 minutes. Though based on values of difference and similarity factors formulations are, not significantly different, ANOVA-based method showed that formulation A and B, B and C, as well as formulation B and D do statistically differ in all 6 time points, meaning they have parallel profiles. The release of paracetamol from formulations A and D is best described by the first order kinetic model, while the release of formulations B and C by the logistic model. Conclusions: The release kinetic of paracetamol is mostly influenced by the type of superdisintegrants and lubricants. Formulation with superdisintegrant technology OptiZorb® demonstrated fastes release rate and thus it is expected to produce the fastest pharmacodynamic effect.

Employing Gamma-Ray-Modified Carbon Quantum Dots to Combat a Wide Range of Bacteria

Nowadays, it is a great challenge to develop new medicines for treating various infectious diseases. The treatment of these diseases is of utmost interest to further prevent the development of multi-drug resistance in different pathogens. Carbon quantum dots, as a new member of the carbon nanomaterials family, can potentially be used as a highly promising visible-light-triggered antibacterial agent. In this work, the results of antibacterial and cytotoxic activities of gamma-ray-irradiated carbon quantum dots are presented. Carbon quantum dots (CQDs) were synthesized from citric acid by a pyrolysis procedure and irradiated by gamma rays at different doses (25, 50, 100 and 200 kGy). Structure, chemical composition and optical properties were investigated by atomic force microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, UV-Vis spectrometry and photoluminescence. Structural analysis showed that CQDs have a spherical-like shape and dose-dependent average diameters and heights. Antibacterial tests showed that all irradiated dots had antibacterial activity but CQDs irradiated with dose of 100 kGy had antibacterial activity against all seven pathogen-reference bacterial strains. Gamma-ray-modified CQDs did not show any cytotoxicity toward human fetal-originated MRC-5 cells. Moreover, fluorescence microscopy showed excellent cellular uptake of CQDs irradiated with doses of 25 and 200 kGy into MRC-5 cells

Drugs with the highest drug expenditure in the Republic of Serbia

Introduction: The policy concerning drugs represents a concentrated effort to achieve better health outcomes for all, with a particular focus on people's access to and rational use of medications. On the basis of pharmacoeconomic analyses, it is possible to modify established prescribing habits, it is possible to influence the creation of guidelines, development strategy and long-term health care planning. Aim: The aim of the work was to determine drugs with the highest expenditure in the Republic of Serbia, and to compare the results obtained in three consecutive years 2016, 2017 and 2018. Also, to analyze which are the most expensive medications listed in the National Register of Medications and what is the trend of changing them. Material and methods: The drug expenditure was monitored using the ATC/DDD methodology. It implies the classification of medications according to the internationally accepted ATC classification of drugs, while DDD, i.e. defined daily dose, is used as a statistical unit for consumption monitoring. The number of DDD/1,000 inhabitants per day provides an insight into how many inhabitants (out of 1,000 of them) used the observed medication and were exposed to its effects during one day. Results: The trend of expenditure of these medications was growing exponentially from 2016 to 2018. The most expensive medications per box are from group J - anti-infective drugs for systemic use and L - antineoplastics and immunomodulators, but their expenditure in the Republic of Serbia is very low. The drugs with the highest price per 1 DDD are: enzymes imiglucerase, laronidase and the biological medication basiliximab in all three years, but considering the indications and rare prescribing, the total cost for these drugs is not high. The largest funds in the Republic of Serbia for the mentioned period were spent on drugs such as: acetylsalicylic acid, paracetamol in combinations, trastuzumab, pantoprazole, amlodipine and rosuvastatin. Comparing the spending on L group of drugs in 2017 compared to 2016, there was a significant increase. Conclusion: The medications with the highest expenditure in the Republic of Serbia are used very little compared to countries with good pharmacotherapy practice. The most expensive drugs are those that are used for special and rare indications, and large amounts of money are not allocated for them as for some cheaper, but more frequently prescribed drugs

Bactericidal and antioxidant bacterial cellulose hydrogels doped with chitosan as potential urinary tract infection biomedical agent

Therapy of bacterial urinary tract infections (UTIs) and catheter associated urinary tract infections (CAUTIs) is still a great challenge because of the resistance of bacteria to nowadays used antibiotics and encrustation of catheters. Bacterial cellulose (BC) as a biocompatible material with a high porosity allows incorporation of different materials in its three dimensional network structure. In this work a low molecular weight chitosan (Chi) polymer is incorporated in BC with different concentrations. Different characterization techniques are used to investigate structural and optical properties of these composites. Radical scavenging activity test shows moderate antioxidant activity of these biocompatible composites whereasin vitrorelease test shows that 13.3% of chitosan is released after 72 h. Antibacterial testing of BC-Chi composites conducted on Gram-positive and Gram-negative bacteria causing UTIs and CAUTIs (Escherichia coli,Pseudomonas aeruginosa,Klebsiella pneumoniae) and encrustation (Proteus mirabilis) show bactericidal effect. The morphology analysis of bacteria after the application of BC-Chi shows that they are flattened with a rough surface, with a tendency to agglomerate and with decreased length and width. All obtained results show that BC-Chi composites might be considered as potential biomedical agents in treatment of UTIs and CAUTIs and as a urinary catheter coating in encrustation prevention

Photoactive and antioxidant nanochitosan dots/biocellulose hydrogels for wound healing treatment

Bacterial infection and their resistance to known antibiotics delays wound healing. In this study, nanochitosan dots (nChiD) produced by gamma irradiation have been encapsulated in bacterial cellulose (BC) polymer matrix to study the antibacterial potentials of these nanocomposites and their possible usage in wound healing treatment (scratch assay). Detailed analyses show that nChiDs have disc-like shape and average diameter in the range of 40 to 60 nm depending of the applied dose. All nChiDs as well as BC-nChiD nanocomposites emit green photoluminescence independently on the excitation wavelengths. The new designed nanocomposites do not have a cytotoxic effect; antioxidant analysis shows their moderate radical scavenging activity whereas antibacterial properties show significant growth inhibition of strains mostly found in difficult-to-heal wounds. The obtained results confirm that new designed BC-nChiD nanocomposites might be potential agent in wound healing treatment.Supplementary material: [http://aspace.agrif.bg.ac.rs/handle/123456789/5993