Synthesis and Characterization of Calcium Alginate-Based Microspheres Entrapped with TiO2 Nanoparticles and Cinnamon Essential Oil Targeting Clinical Staphylococcus aureus.

It is important to create new generations of materials that can destroy multidrug-resistant bacterial strains, which are a serious public health concern. This study focused on the biosynthesis of an essential oil entrapped in titanium dioxide (TiO2) calcium alginate-based microspheres. In this research, calcium alginate-based microspheres with entrapped TiO2 nanoparticles and cinnamon essential oil (CI-TiO2-MSs) were synthesized, using an aqueous extract of Nigella sativa seeds for TiO2 nanoparticle preparation, and the ionotropic gelation method for microsphere preparation. The microspheres obtained were spherical, uniformly sized, microporous, and rough surfaced, and they were fully loaded with cinnamon essential oil and TiO2 nanoparticles. The synthesized microspheres were analyzed for antibacterial activity against the clinical multidrug-resistant strain of Staphylococcus aureus. Disc diffusion and flow cytometry analysis revealed strong antibacterial activity by CI-TiO2-MSs. The synthesized CI-TiO2-MSs were characterized by the SEM/EDX, X-ray diffraction, and FTIR techniques. Results showed that the TiO2 nanoparticles were spherical and 99 to 150 nm in size, whereas the CI-TiO2-MSs were spherical and rough surfaced. Apoptosis analysis and SEM micrography revealed that the CI-TiO2-MSs had strong bactericidal activity against S. aureus. The in vitro antibacterial experiments proved that the encapsulated CI-TiO2-MSs had strong potential for use as a prolonged controlled release system against multidrug-resistant clinical S. aureus.

Targeting microbial biofilms: by Arctium lappa l. synthesised biocompatible CeO2-NPs encapsulated in nano-chitosan.

This study is planned to synthesise new biocompatible, nano antimicrobial formulation against biofilm producing strains. Aqueous root extract of Arctium lappa l. was used to synthesise ceria nanoparticles (CeO2-NPs). The synthesised nanoparticles were encapsulated with nano-chitosan by sol-gel method and characterised using standard techniques. Gas chromatography-mass spectrometer of Arctium lappa l. revealed the presence of ethanol, acetone, 1- propanol, 2-methylethane, 1,1-di-ethoxy, 1-Butanol, and oleic acid acted as reducing and surface stabilising agents for tailoring morphology of CeO2-NPs. Erythrocyte integrity after treatment with synthesised nanomaterials was evaluated by spectrophotometer measurement of haemoglobin release having biocompatibility. Scanning electron microscopy revealed the formation of mono dispersed beads shaped particles with mean particle size of 26.2 nm. X-ray diffractometry revealed cubic crystalline structure having size of 28.0 nm. After encapsulation by nano-chitosan, the size of CeO2-NPs enhances to 48.8 nm making average coverage of about 22.6 nm. The synthesised nanomaterials were found effective to disrupt biofilm of S. aureus and P. aeruginosa. Interestingly, encapsulated CeO2-NPs revealed powerful antibacterial and biofilm disruption activity examined by fluorescent live/dead staining using confocal laser scanning microscopy. The superior antibacterial activities exposed by encapsulated CeO2-NPs lead to the conclusion that they could be useful for controlling biofilm producing multidrug resistance pathogens.

In vitro antifungal activity of 9, 10-dihydrophenanthrene-2-carboxylic acid isolated from a marine bacterium: Pseudomonas putida.

An antifungal compound 9, 10-dihydrophenanthrene - 2 - carboxylic acid was isolated from a marine derived bacterium Pseudomonas putida isolated from surface water samples of Karachi fish harbor coast line. The structure was explored using extensive 1D- and 2D-NMR spectroscopic techniques. The compound was found to be active against fungal strains obtained from clinical samples whereas strong activity was noted against Candida albicans with a MIC value of 20µg/ml, as the purified compound showed promising anticandidal activity a multidisciplinary approach is needed to explore further this compound as potential pharmacological lead compound against Candida spp and will add in the global hunt for clinically functional antifungal agents.

Synthesis, characterization and evaluation of antibacterial activity of copper oxide nanoparticles against clinical strains of Staphylococcus aureus.

Bacterial resistance is spreading globally due to excessive use of antibiotics, making it one of our times biggest challenges. To address this issue present study was conducted to evaluate the antibacterial activity of copper oxide nanoparticles against methicillin-resistant S. aureus (MRSA). Copper oxide nanoparticles were synthesized by chemical precipitation method and were characterized by UV-Visible, FT-IR spectroscopy, X-ray diffraction (XRD) and Scanning Electron Microscopy. These nanoparticles of 27nm were assessed for antibacterial activity using disc diffusion method. Our results showed superb inhibitory effects of CuO nanoparticles with increase in concentration and complete inhibition was recorded against tested strains of S. aureus at 100µl/ml and 125µl/ml concentration. The study concludes that the drugs which do not show any inhibitory effects against resistant bugs could be augmented with CuO nanoparticles to achieve the treatment goal.

Isolation and characterization of antibiotic producing bacterial strains from red soil of Himalayan region of Pakistan.

The emergence of multi drug resistant microbial pathogens has become a global health challenge and set a dire requirement of searching new effective antimicrobials. Soil is an ultimate reservoir of biologically active micro flora, which harbors trillions of microbial strains producing compounds of commercial interest. Hence aim of the present study was an attempt to isolate and identify the antibiotic producing microbial strains from the red soil of Himalayan an unexplored region of Pakistan. In this study from 10 different soil samples only one bacterial strain was isolated capable of antimicrobial activity. Strain was identified by biochemical characteristics and final identification was done by API 20 NE kit which showed 99% homology with P. aeruginosa. Hence the strain was identified as P. aeruginosa S2. Antibacterial and antifungal activity of the P. aeruginosa S2 showed that Staphylococcus aureus was extremely sensitive to it with a zone of inhibition of 42mm. Staphylococcus epidermidis, Enterobacter aerogenes, Aspergillus fumigatus and Candida albicans were also inhibited by the isolated strain. Effect of Glycerol, Copper sulphate (CuSo4), Sodium sulphate (Na2SO4) and Glycerol on antibiotic production was also evaluated by supplementing growth media with these chemicals. Pseudomonas aeruginosa was grown in bulk quantity using solid state fermentation and crude extract was prepared using organic solvents and subjected to silica gel column chromatography for purification of active compound. Purified compound showed antibacterial against human pathogens. The unexplored Kashmir Himalayas are of great significance because of its richness in biodiversity and need to be explored for isolation and characterization of native microbes for biologically active secondary metabolites. This untouched region may be considered as hub of new antimicrobials and may have applications in natural product-based drug discovery.

Essential oils showing in vitro anti MRSA and synergistic activity with penicillin group of antibiotics.

This study was planned in order to investigate effective essential oils to inhibit in-vitro growth of Methicillin resistant Staphylococcus aureus (MRSA). In this study using disc diffusion method anti MRSA activity of ten diverse essential oils extracted from traditional plants namely Thymus vulgaris L, Mentha pulegium, Ocimum sanctum, Mentha piperita, Cymbopogon citratus, Rosmarinus officinalis L., Cortex cinnamom, Citrus nobilis x Citrus deliciosa, Origanum vulgare and Mentha sp. was examined. All the essential oils inhibited growth of S. aureus to different extent, by exhibiting moderate to elevated zones of inhibitions. Essential oils of cinnamon (Cortex cinnamomi) and thyme (Thymus vulgaris L) were observed to be the most powerful against MRSA strains used in this study. At lowest concentration of 25µl/ml essential oils comprehensible zone of inhibition was found 9±0.085mm and 8±0.051mm respectively, and at elevated concentrations there was a total decline in growth of MRSA and a very clear zone of inhibition was observed. A synergistic effect of essential oils in amalgamation with amoxicillin a Penicillin group of antibiotic was also examined. Interestingly a strong synergism was observed with oregano (Origanum vulgare) and pennyroyal mint (Mentha pulegium) essential oils, which were not so effective alone driven out to be important synergistic candidate. Our results demonstrated that essential oils of cinnamon and thyme can be used as potential antimicrobial agent against the Methicillin-resistant Staphylococcus aureus infections and Amoxicillin antibacterial activity can be enhanced using active constituents present in oregano and pennyroyal mint essential oils.

Anterior arch crowding--a possible predictor for mandibular third molar impaction.

BACKGROUND: Impaction of the 3rd molar is a high incident problem occurring in up to 73% of young adults in Europe. Appropriate follow-up routines and optimal timing for surgical removal of the 3rd molars can be established in patients judged to be at increased risk of impaction. The purpose of this study was to identify risk factors for mandibular 3rd molar impaction in adolescent orthodontic patients and to establish anterior arch crowding as a predictive model for mandibular 3rd molar impaction. METHODS: Pre-treatment Orthopantomogram (OPG) of 158 orthodontic patients with the evidence of anterior arch crowding on pre-treatment study models were evaluated for mandibular third molar position. RESULTS: Out of 158 patients, 45 were male and 113 were female. Ninety-seven (61%) of the patients showed anterior arch crowding with a space discrepancy of 5-10 mm calculated on the pretreatment study models. Fifty-seven patients showed 107 third molar impactions. Anterior arch crowding in these patients was ranging from 7-10 mm. Out of 107 impacted third molars 73 were Mesioangular 14 were Distoangular 6 were Vertical and 14 were Horizontal. CONCLUSION: If the arch size is smaller as compared to the tooth size the evidence of lack of space would be there in anterior segment as crowding and in posterior segment as 3rd molar impaction.