Confocal Laser Scanning Microscopy Studies Research Articles

Highly Stable Core-Shell Nanocolloids: Synergy between Nano-Silver and Natural Polymers to Prevent Biofilm Formation.

Active investment in research time in the development and study of novel unconventional antimicrobials is trending for several reasons. First, it is one of the ways which might help to fight antimicrobial resistance and bacterial contamination due to uncontrolled biofilm growth. Second, minimizing harmful environmental outcomes due to the overuse of toxic chemicals is one of the highest priorities nowadays. We propose the application of two common natural compounds, chitosan and tannic acid, for the creation of a highly crosslinked polymer blend with not only intrinsic antimicrobial properties but also reducing and stabilizing powers. Thus, the fast and green synthesis of fine spherically shaped Ag nanoparticles and further study of the composition and properties of the colloids took place. A positively charged core-shell nanocomposition, with an average size in terms of the metal core of 17 ± 4 nm, was developed. Nanoantimicrobials were characterized by several spectroscopic (UV-vis and FTIR) and microscopic (transmission and scanning electron microscopies) techniques. The use of AgNPs as a core and an organic polymer blend as a shell potentially enable a synergistic long-lasting antipathogen effect. The antibiofilm potential was studied against the food-borne pathogens Salmonella enterica and Listeria monocytogenes. The antibiofilm protocol efficiency was evaluated by performing crystal violet assay and optical density measurements, direct visualization by confocal laser scanning microscopy and morphological studies by SEM. It was found that the complex nanocomposite has the ability to prevent the growth of biofilm. Further investigation for the potential application of this stable composition in food packaging will be carried out.

Cyclodextrin Nanosponge Based Babchi Oil Hydrogel Ameliorates Imiquimod-induced Psoriasis in Swiss Mice: An Impact on Safety and Efficacy

Background: Psoriasis, a chronic autoimmune disease, involves the integration of biological and molecular events by hyperproliferation of the epidermal keratinocytes and generation of inflammation markers. Owing to severe complications of synthetic corticosteroids, there is a strong need for a potential and safe alternative. Babchi oil (natural essential oil; BO) may prove to be a promising natural agent for psoriasis. Objective: The aim of the present work was to investigate the safety and efficacy of cyclodextrin nanosponge based babchi oil (BONS) hydrogel on skin annexes. Methods: Babchi Oil Nanosponge Hydrogel (BONS-HG) was fabricated and evaluated. Cell viability studies have been carried out on THP1 cell lines to evaluate cytocompatibility. Irritation potential and in vivo visualization of cutaneous uptake of BONS-HG were carried out using Hen’s Egg Chorioallantoic Membrane Test (HET-CAM) and Confocal Laser Scanning Microscopy (CLSM), respectively. The nano hydrogel was tested in vivo using imiquimod-induced psoriasis mouse model. Results: The in vitro irritation potential of BONS-HG indicated no sign of erythema or irritation, suggesting the safety of prepared hydrogel as topical formulation. CLSM studies advocated targeting of BO to epidermis and dermis. Along with histopathological assessment, evaluation of oxidative stress markers revealed the significant antipsoriatic activity (p< 0.001) of the prepared BONS-HG. Conclusion: The present study amalgamated the advantages of natural essential oil with this approach for skin targeting and provided an effective and safe topical alternative for psoriasis.

Intratubular penetration capacity of HiFlow bioceramic sealer used with warm obturation techniques and single cone: A confocal laser scanning microscopic study

ObjectiveThe aim of this paper was to evaluate the intratubular penetration area of a bioceramic sealer, using continuous wave (CW), vertical condensation (VC) with two different types of gutta-percha (conventional (NG) and bioceramic-coated (BG)) and single cone (SC) technique with BG gutta-percha, in different root thirds. MethodsA total of 150 mature single-root human teeth (including incisors, canines and premolars) were prepared and randomly divided into five groups (n = 30). Teeth were filled using a bioceramic sealer (TotalFill BC Sealer HiFlow ®) and two different types of gutta-percha, with CW and VC techniques, the teeth in the control group were filled with SC technique and BG gutta-percha. The teeth were sectioned and evaluated as one-third portions in each case under a confocal laser microscope. The penetration area measurements were carried out with the Autocad ® programme. Data was analyzed using the one-factor ANOVA test (p < 0.05) and Post Hoc Test (p < 0.05). ResultsThe ANOVA Test showed significant differences in the penetration areas of the five obturation techniques (P < 0.05). The Post Hoc Test exhibited significant differences in multiple comparisons (P < 0.05). There was more dentinal tubule penetration in the coronal third than in the apical third in all techniques. ConclusionsThe intratubular penetration of the bioceramic sealer was influenced by the obturation techniques tested, but not by the different gutta-percha tested. There was more penetration of sealer in the warm obturation techniques than the SC, regardless of the type of gutta-percha used.

Anti-virulence properties of catechin-in-cyclodextrin-in-phospholipid liposome through down-regulation of gene expression in MRSA strains

Methicillin resistant Staphylococcus aureus (MRSA) is a prime pathogen responsible for various infections in human beings. Expression of virulence factors is a biggest challenge in MRSA, which results in failure of conventional antibiotic therapy. In connection to the search for natural and safe anti-virulence compounds, the present study focused to evaluate the anti-virulence potential of catechin-in-cyclodextrin-in-phospholipid liposome (CCPL) on MRSA strains. CCPL inhibited young biofilm (64.15–72.70%) as well degraded mature biofilm (55.60–63.65%) at ½ and ¼ MIC doses, which was further confirmed by scanning electron microscopy and confocal laser scanning microscope studies. CCPL was capable enough to modify the surface hydrophobicity (40.26–48.59%), reduce the EPS production (1.71–2.25 folds) and bacterial motility. In addition, CCPL inhibited the synthesis of virulence factors like slime production (0.40–0.50 folds), DNase production, hemolytic activity (28.08–49.07%), proteolytic production (14.65–18.04%), lipase production, autolysis and cell auto-aggregation. CCPL prevented the staphyloxanthin production and thereby increased the susceptibility of MRSA strains towards H2O2. Further, CCPL significantly down-regulated the virulence genes (agrA, agrC, clfA, clfB, fnbA, fnbB, icaA, icaD, hla, hld, rna III, atlA, sarA, sigB & geh). Thus, the results of present study revealed that the CCPL can effectively reduce the virulence properties and its application could inhibit the pathogenicity and also prevents the development of drug-resistance in MRSA strains.

Comparison of bioceramic and epoxy resin sealers in terms of marginal adaptation and tubular penetration depth with different obturation techniques in premolar teeth: A scanning electron microscope and confocal laser scanning microscopy study.

ABSTRACTIntroduction and ObjectiveThe proper performance of a sealer in root canal treatment depends on its physical properties. The aim of this study was to investigate the effect of two bioceramic and epoxy resin sealers in terms of marginal adaptation and tubular penetration depth in different obturation methods of human premolar teeth.Materials and MethodsA total of 82 premolar teeth extracted due to caries and gum disease were used in the present in vitro experimental study. Two types of sealers, epoxy resin (AH-Plus, Dentsply, Germany) and bioceramic (Endosequence BC sealer, Brasseler, Savannah, GA, USA), were used in this research. Lateral compaction and single-cone techniques were used for filling the teeth. Marginal adaptation and tubular penetration depth were measured by scanning electron microscopy (SEM) and confocal laser scanning microscope (CLSM), respectively. Statistical analysis of data was performed by repeated-measures ANOVA. The significance level was considered as P < 0.05.ResultsThe marginal adaptation and tubular penetration depth in all three coronal, middle, and apical regions were better in bioceramic sealer (P < 0.001). The marginal adaptation and tubular penetration depth in all regions were not affected by the filling method and the interaction between the sealer type and the obturation technique.ConclusionBased on the results of this study, the use of bioceramic sealer caused better depth of tubular penetration and marginal adaptation compared to epoxy resin. Further studies and the use of different filling techniques are necessary to achieve a three-dimensional sealing in curved root canals.

Pollen characters and their evolutionary and taxonomic significance: using light and confocal laser scanning microscope to study diverse plant pollen taxa from central India

Increasing the taxonomic resolution of fossil pollen identification and establishing the kinship and similarity among phylogenetically related plant groups are inevitable for advancing the Quaternary palaeoecological, palaeoclimatological and palaeoenvironmental research. We, in the present study, examined and determined the pollen morphological characteristics of nine plant taxa belonging to seven families from central India by a combined light microscopic (LM) and confocal laser scanning microscopic (CLSM) study. The prime object was to observe, document and describe, as well as illustrate the prevalent variation in pollen shape, size, aperture number and diameter, diameter of the polar axis and equatorial distance, as well as exine thickness and pattern (i.e. pollen wall architecture) of the studied plant taxa. Pollen identification key was developed to demonstrate variations in pollen features and delimit taxa for correct identification. Principal component analysis (PCA) suggests exine and aperture number as dominant characters, as well as hierarchical clustering analysis (HCA), applied to the pollen morphological characters of nine plant taxa to understand the variability among the taxa, and to cluster them, respectively, suggest three clusters. The cophenetic correlation coefficient also substantiates the three group of clustering. The present study has significance in taxonomy and systematics, as well as in phylogeny and evolution. In addition, the preservation potential of different pollen grains has been ascertained, based on the pollen wall architecture. The study, moreover, will improve the precise fossil pollen identification, which is critical for advancing Quaternary palaeoecology in India and also in similar tropical and subtropical areas of the globe.

Fluorescein/gold nanoparticles conjugated EGFR antibody for imaging and P53 upregulation in hamster mucosal cells carcinoma

The epidermal growth factor receptor (EGFR) has an imperative role in cancer evolution and progression. Gold nanoparticles (GNPs) have outstanding utilization in targeting, and diagnosis of cancers, especially when coupled with antibodies. In this study, the GNPs were conjugated with Anti-EGFR then labeled with fluorescein isothiocyanate (FITC) for targeting tumor-induced in hamster mucosal cells using a confocal laser scanning microscope (CLSM). Anti-EGFR-GNPs-FITC was prepared by mixing 10 mL of the gold solution with 1 mL antibody solution then 0.5 mL of 1% polyethylene glycol (PEG) was added to the mixture to prevent aggregation. FITC was added to the previous solution and stirred overnight. Characterization of GNPs and Anti-EGFR-GNPs-FITC was done by UV–Vis, TEM, and Zeta potential. CLSM study of tissue treated with Anti-EGFR-GNPs-FITC reveals the successful distribution and bioconjugation of Anti-EGFR-GNPs-FITC in tumor cells. The best time for distribution in tumor tissue was between 6 and 8 h. In addition, a real-time PCR study showed an increase in mean values of P53 (tumor suppressor gene) expression in both normal and tumor-induced cells. The up-regulation in gene expression of P53 means using Anti-EGFR-GNPs-FITC will help in suppressing the tumor cells growth. This study acquaints an innovative GNPs antibody assemblage (Anti-EGFR-GNPs-FITC) that was successful in both bioconjugation and tumor suppression in mucosal cells.

Experimental Designs to Study the Aggregation and Colonization of Biofilms by Video Microscopy With Statistical Confidence.

The goal of this study was to quantify the variability of confocal laser scanning microscopy (CLSM) time-lapse images of early colonizing biofilms to aid in the design of future imaging experiments. To accomplish this a large imaging dataset consisting of 16 independent CLSM microscopy experiments was leveraged. These experiments were designed to study interactions between human neutrophils and single cells or aggregates of Staphylococcus aureus (S. aureus) during the initial stages of biofilm formation. Results suggest that in untreated control experiments, variability differed substantially between growth phases (i.e., lag or exponential). When studying the effect of an antimicrobial treatment (in this case, neutrophil challenge), regardless of the inoculation level or of growth phase, variability changed as a frown-shaped function of treatment efficacy (i.e., the reduction in biofilm surface coverage). These findings were used to predict the best experimental designs for future imaging studies of early biofilms by considering differing (i) numbers of independent experiments; (ii) numbers of fields of view (FOV) per experiment; and (iii) frame capture rates per hour. A spreadsheet capable of assessing any user-specified design is included that requires the expected mean log reduction and variance components from user-generated experimental results. The methodology outlined in this study can assist researchers in designing their CLSM studies of antimicrobial treatments with a high level of statistical confidence.

Nanostructured lipid carrier for transdermal gliclazide delivery: development and optimization by Box-Behnken design

The aim of current study was to prepare and optimize the nanostructured lipid carrier (NLC) for transdermal gliclazide (GCZ) delivery. The melt emulsification followed by ultrasonication technique was utilized to prepare GCZ–loaded-NLC. The optimization of NLC was achieved by Box-Behnken design. The surfactant (Tween 20) % (X1), total lipid (glyceryl monostearate + Lauroglycol™ 90) % (X2), and sonication time (min) (X3) were chosen as independent variables, while particles size (Y1), polydispersity index (Y2), and entrapment efficiency (Y3) were selected as response. Further, the prepared NLC was estimated for in vitro drug release study, ex vivo skin permeation and confocal laser scanning microscopy (CLSM) studies. Results of present study demonstrated that the optimized GCZ loaded NLC formulation presented the particles size, polydispersity index, zeta potential, and entrapment efficiency of 120.4 nm, 0.316, −5.58 mV, and 87.32% respectively. The in vitro drug release study indicated drug release of 68.27 ± 2.98% and 45.87 ± 2.85% for GCZ-NLC and conventional GCZ dispersion respectively. The GCZ-NLC-Gel formulation exhibited transdermal drug permeation of 76.89 ± 2.52% as compared to conventional gel (45.65 ± 2.79%). The CLSM of rat skin treated with NLC gel exhibited a deeper permeation (35 μm) in comparison to the conventional gel (15 μm). In conclusion, GCZ loaded NLC was successfully optimized using Box-Behnken design that contributed many advantages over conventional formulation and thus demonstrating NLC as propitious carriers for the transdermal GCZ delivery.

Value addition property of a cationic surfactant on endodontic irrigant: A confocal laser scanning microscope study.

Introduction:Chlorhexidine (CHX) is a commonly used root canal irrigant with high surface tension which prevents its penetration into the isthmus and fins of the root canal. Surfactants have known to reduce the surface tension of the liquid. Cetylpyridinium chloride (CPC) is a cationic surfactant. The aim of this study is to assess the contact angle formed and depth of penetration of the endodontic irrigant with and without the addition of surfactant.Methods:Contact angle analysis – Ninety-nine freshly extracted and cleaned single-rooted mandibular premolars were obtained. Thirty-three teeth were sectioned longitudinally and then transversely. The sections were mounted on an acrylic block, polished to obtain a flat dentin surface. Five microliter of Group 1: 2% CHX as control, Group 2: 2% CHX + 0.1% CPC, and Group 3: 2% CHX + 0.2% CPC were placed on the dentin surface and subjected to contact angle analysis. Depth of penetration – Access cavity was prepared in sixty-six teeth and instrumented to working length till Protaper Gold F2. The samples were assigned to Groups 1, 2, and 3 and irrigated accordingly, and subjected to a confocal laser scanning Microscopy. Data were analyzed using one-way ANOVA and Tukey multiple comparison test. Karl Pearson's correlation test was performed to analyze the correlation between the two.Results:Group 3 had the lowest contact angle (12.82°) and the highest depth of penetration (222.74 μm) when compared to Group 1 and Group 2. Karl Pearson's correlation showed no correlation between the contact angle and the depth of penetration.Conclusion:Higher the concentration of CPC, lower is the contact angle formed with the dentin and higher is the depth of penetration into the dentinal tubule.

Carnosic Acid as an intracanal medicament performs better than triple antibiotic paste and calcium hydroxide to eradicate Enterococcus faecalis from root canal: An in vitro confocal laser scanning microscopic study.

Background:Carnosic acid is an herbal derivative with potent antioxidant, anti-inflammatory, antimicrobial, and anticancer properties.Aim:Comparative evaluation of the antimicrobial potential of carnosic acid, calcium hydroxide, and triple antibiotic paste as intracanal medicaments against Enterococcus faecalis.Settings and Design:Department of Conservative Dentistry and Microbiology, an in vitro study.Materials and Methods:Fifty-two extracted single-rooted human teeth were decoronated and chemomechanical preparation was performed. The specimens were secured in the center of screw-capped vials and autoclaved. A strain of E. faecalis was inoculated into the canals and grown for 72 h. The teeth were divided into: Group I-Ca(OH)2, Group II- triple antibiotic paste (TAP), Group III-Carnosic acid, and Group IV-Negative control. The medicaments were applied in the canal and left for 14 days. The specimens were sectioned transversely at three levels to create dentinal discs and observed under the confocal laser scanning microscopic (CLSM). Images were analyzed, and quantification of bacteria was done using the Image J software.Statistical Analysis:Mean percentage of live/dead bacteria was analyzed using One-way ANOVA and Post hoc Tukey test.Results:Mean percentages of live and dead bacteria were seen under CLSM in Group I, Group II, and Group III were (4.44 ± 2.87, 4.56 ± 2.93, 1.61 ± 1.90), and (4.59 ± 3.04, 4.25 ± 2.98, 1.70 ± 1.99), respectively, with least mean percentages for live and dead bacteria in carnosic acid (Group III).Conclusion:Carnosic acid showed better antimicrobial efficacy against E. faecalis than TAP and Ca(OH)2 by showing a low percentage of both live and dead bacteria.

Effect of sonic and ultrasonic irrigation on improving root canal cleanliness after post space preparation: A confocal laser scanning microscopic study

Introduction: Removing the secondary smear layer has been presumed to increase the micromechanical retention of fiber posts. The additional use of irrigation techniques is intended to improve the cleanliness of the root canal walls. The present study aimed to determine the effectiveness of sonic and ultrasonic irrigation techniques on root canal cleanliness after the post space preparation.Materials and Methods: A total of 27 extracted single-rooted premolar samples underwent root canal treatment using gutta-percha and AH Plus that was labeled with rhodamine B. Gutta-percha was removed during the post preparation. The sample was then divided into three groups (n = 9): irrigation with sonic activation, ultrasonic activation, or without activation, respectively. The teeth were subsequently cut in the middle third area of the root, and the remnant of smear layers was observed using a confocal laser scanning microscope. Cleanliness was expressed as a percentage of the angle that contained part of the red area representing the smear layer. The results were statistically analyzed with a one-way ANOVA test and post hoc Bonferroni test set at 5% significance level.Results: The sonic group had the greatest percentage of root canal wall cleanliness (89.00 ± 2.77), followed by the ultrasonic (78.33 ± 3.09) and nonactivated groups (67.77 ± 3.37). Conversely, there was no significant difference in root canal wall cleanliness between the sonic and ultrasonic groups (P = 0.067) or the ultrasonic and nonactivation groups (P = 0.071).Conclusions: Irrigation with sonic activation improved cleanliness of the root canal dentinal wall after post space preparation.

Effect of Fluoride Recharge on the Microleakage of Fluoride-Releasing Restorative Materials: An Ex Vivo Confocal Laser Scanning Microscopy Study.

ABSTRACTContext:Success or failure of a restoration depends on its ability to bond to the tooth structure, to reduce microleakage, and to inhibit secondary caries. Fluoride-releasing materials have the inherent potential to release fluoride and are also capable of recharging themselves with topical agents.Aim:The aim of this study was to compare and evaluate the effect of fluoride recharge on microleakage of different restorative materials.Materials and Methods:Eighty extracted teeth were collected and split mesiodistally into 160 specimens. Class V cavities were prepared on buccal and lingual surfaces. Specimens were divided into four groups of 40 each based on the restorative material. Group I: Glass ionomer; Group II: Resin composite; Group III: Giomer; and Group IV: Alkasite. The restored teeth were stored in artificial saliva. Each group was divided into four subgroups for fluoride recharge and subsequent confocal laser scanning microscopy (CLSM) examination: (A) no fluoride recharge and CLSM examination after 24 h, (B) no fluoride recharge and CLSM examination after 3 weeks, (C) fluoride recharge once at third week followed by CLSM examination at 6 weeks, and (D) fluoride recharge twice at third week and sixth week followed by CLSM examination at 9 weeks.Statistical Analysis:Kruskal−Wallis and Mann−Whitney U tests were performed to analyze the obtained data.Results:A significant difference in microleakage was noted among resin composite and other groups except Cention-N, whereas no significant difference was noted pre- and post-fluoride recharge.Conclusion:Increased microleakage was noted post-fluoride recharge, although statistically not significant.

Influence of the Remnants of Silicone Oil on Penetration of Three Different Sealers into the Dentinal Tubules: A Confocal Laser Scanning Microscopy Study.

The aim of this study was to assess penetration of AH Plus, MTA Fillapex and GuttaFlow Bioseal sealers into dentinal tubules after placement and removal of silicone oil using Confocal Laser Scanning Microscopy. Sixty single-canaled premolars were instrumented using ProTaper Universal rotary system. Roots were divided into two main groups (n=30) where either Silicone oil was used or not. Subsequently, each main group was subdivided into 3 subgroups according to the investigated sealers. In subgroups where Silicone oil was used, it was placed in canals and then cleared. Obturation was completed utilizing lateral compaction technique using Rhodamine B labeled sealers. Penetration depth of sealer was evaluated by image J software. One way ANOVA, Duncan's test as posthoc test was performed for evaluation of statistical significances among the groups. In each sealer group, Independent -t-test was used to compare between with and without oil. P value was set at <0.05. Using silicone oil resulted in less dentinal tubule penetration depth with all sealers. Mean dentinal tubule penetration depth was the lowest in apical thirds. AH Plus showed higher penetrability in all thirds compared to MTA Fillapex and GuttaFlow Bioseal despite oil placement and removal. MTA Fillapex displayed higher penetrability in all thirds than GuttaFlow Bioseal. Remnants of silicone oil has a negative impact on the penetration depth of the tested sealers.

Fabrication of hydrolase responsive diglycerol based Gemini amphiphiles for dermal drug delivery applications.

Since biocatalysts manoeuvre most of the physiological activities in living organisms and exhibit extreme selectivity and specificity, their use to trigger physicochemical change in polymeric architectures has been successfully used for targeted drug delivery. Our major interest is to develop lipase responsive nanoscale delivery systems from bio-compatible and biodegradable building blocks. Herein, we report the synthesis of four novel non-ionic Gemini amphiphiles using a chemo-enzymatic approach. A symmetrical diglycerol has been used as a core that is functionalised with alkyl chains for the creation of a hydrophobic cavity, and for aqueous solubility (polyethylene glycol) monomethyl ether (mPEG) is incorporated. Such systems can exhibit a varied self-assembly behaviour leading to the observance of different morphological structures. The aggregation behaviour of the synthesised nanocarrier was studied by dynamic light scattering (DLS) and critical aggregation concentration (CAC) measurements. The nanotransport potential of amphiphiles was investigated for hydrophobic guest molecules, i.e. Nile red, nimodipine and curcumin. Cytotoxicity of the amphiphiles was studied using HeLa and MCF7 cell lines at different concentrations, i.e. 0.05, 0.1, and 0.5 mg mL−1. All nanocarriers were found to be non-cytotoxic up to a concentration of 0.1 mg mL−1. Confocal laser scanning microscopy (cLSM) study suggested the uptake of encapsulated dye in the cytosol of the cancer cells within 4 h, thus implying that amphiphilic systems can efficiently transport hydrophobic drug molecules into cells. The biomedical application of the synthesised Gemini amphiphiles was also investigated for dermal drug delivery. In addition, the enzyme-mediated release study was performed that demonstrated 90% of the dye is released within three days. All these results supported the capability of nanocarriers in drug delivery systems.

The combined occluding effect of sodium fluoride varnish and erbium: Yttrium-aluminium-garnet laser irradiation on dentinal tubules − CLSM and SEM study

Introduction: Dentin hypersensitivity (DH) is one of the most common problems, but to date, no single agent or form of treatment has been found effective. Lasers have promising potential for the treatment of DH. This in vitro study aims to compare and evaluate the desensitising ability of a combination of sodium fluoride varnish (NaF) and Erbium: yttrium-aluminium-garnet (Er: YAG) laser by assessing tubule occlusion and depth of penetration of the agent in dentinal tubules through Scanning electron microscope (SEM) and Confocal laser scanning microscope (CLSM), respectively. Materials and Methods: Forty-five extracted maxillary premolar teeth were included in this study. A 3-mm-thick horizontal slice was prepared from the cementoenamel junction of each tooth. Each slice was transversely separated into two halves as buccal and lingual samples. Ninety samples were obtained, and these samples were randomly divided into six equal groups. Groups A, B, C, and D were used for the evaluation of tubule occlusion with SEM Groups E and F were evaluated for dentin permeability with CLSM. Results: Intergroup comparisons showed statistically significant differences among groups, and it was observed that the combined use of Sodium fluoride and Er: YAG Laser showed better occluding (Group D) and depth penetration (Group F) effect when analysed using SEM and CLSM, respectively. Conclusion: It can be concluded that a combination of fluoride varnish and lasers offers a significant role in dentinal hypersensitivity.

Effect of Fluidized Bed Drying, Matrix Constituents and Structure on the Viability of Probiotic Lactobacillus paracasei ATCC 55544 during Storage at 4 °C, 25 °C and 37 °C.

The stabilization of probiotics for application in non-refrigerated food products is a challenging task. In the present study, probiotic Lactobacillus paracasei (Lacticaseibacillus paracasei) ATCC 55544 cells were immobilized in a dairy matrix comprising of whole milk powder, skim milk powder, or milk protein isolate using fluidized bed drying technology. The samples were taken out at different drying stages, with an apparent water activity (aw) of aw 0.5, aw 0.4, and aw 0.3, respectively, and vacuum-packed to maintain the aw and stored at three different temperatures of 4 °C, 25 °C, and 37 °C. The study evaluated the impact of matrix constituents, milk fat, protein, and carbohydrate on the viability of encapsulated probiotic L . paracasei ATCC 55544 during storage for 1 month. The whole milk powder matrix provided superior protection to the bacteria. Confocal Laser Scanning Microscopy (CLSM) was used to investigate the structure of the immobilizing matrix and the location of the probiotic L. paracasei cells embedded within the matrix. The CLSM study revealed that the probiotic bacterial cells are mostly embedded as clusters beneath the top layer. We hypothesize that the biofilm-like structure, together with the protective whole milk powder matrix, helps to retain the superior viability of probiotic cells during storage at non-refrigerated storage conditions of 25 °C and 37 °C.

Structural Rationale towards Designing Coordination Polymer Based Metallogels Displaying Anti‐Cancer and Anti‐Bacterial Properties

AbstractA new series of organic‐inorganic‐hybrid‐systems (OIHS) was synthesized with the aim of developing metallogels that might display ‘drug‐like’ function. Reaction of two dicarboxylate ligands namely 3‐carboxycinnamic acid (3‐cca) and 4‐carboxycinnamic acid (4‐cca) with various bivalent metal ions (Cu(II), Zn(II), Co(II), Cd(II), Mn(II)) produced a new series of OIHS which were crystallographically characterized; five of which were coordination polymers (CP1‐CP5) and one metal‐organic polyhedra (MOP‐1). Reaction of 3‐cca with various metal ions in presence of DMSO/water produced five metallogels (MG1‐MG5) of which the Zn(II)‐metallogel namely MG1 was evaluated for both anti‐cancer and anti‐bacterial properties against murine tumor cell line B16‐F10 (human skin cancer model) and gram positive bacterium S. aureus. While MTT and cell migration assays established the anti‐cancer activity of MG1 against B16‐F10, flow cytometry and laser scanning confocal microscopy (LSCM) images under various staining conditions supported apoptotic pathway of cancer cell death. Anti‐bacterial ability of MG1 was also established against S. aureus by zone inhibition, and flow cytometry and LSCM studies under various staining conditions. MG1 was also demonstrated to be effective in killing the intracellular bacterial cells when B16‐F10 cells were infected with S. aureus thereby suggesting its potential in treating post‐operative cancer surgery model system.

Glucose-Induced Biofilm Formation in Bacillus thuringiensis KPWP1 is Associated with Increased Cell Surface Hydrophobicity and Increased Production of Exopolymeric Substances.

Bacillus thuringiensis is an agriculturally and medically important bacteria as it produces insecticidal Cry proteins and can form biofilm on different plant surfaces. Previous studies reported that the ubiquitous carbon source glucose could induce restricted motility and fractal pattern formation in the growing colonies of pH, salt and arsenate tolerant Bacillus thuringiensis KPWP1. As bacteria are evolved with the ability to exhibit multicellular behavior and biofilm formation under limiting conditions for survival, the present study was focused on exploring the effect of glucose in biofilm formation by Bacillus thuringiensis KPWP1. A significant rise in biofilm loads was observed with increased glucose concentrations in growth media. Compared to control, six times more biofilm load was marked in presence of 2% of glucose. Interestingly, it was observed that the effect was glucose specific and also not due to any change in the sugar-induced physicochemical property of the growth media as the addition of galactose or arabinose could not induce any significant increase in KPWP1 biofilm load. Scanning electron-, confocal laser scanning-microscopic studies and biochemical tests revealed that increased concentrations of glucose could induce increased production of exopolymeric substances, increased number of densely-packed micro-colonies in KPWP1 biofilm and increased hydrophobicity and adherence properties in KPWP1cells.

Oxidative Damage Induced by Phototoxic Pheophorbide a 17-Diethylene Glycol Ester Encapsulated in PLGA Nanoparticles.

Pheophorbide a 17-diethylene glycol ester (XL-8), is a promising high-active derivative of known photosensitizer chlorin e6 used in photodynamic therapy. However, high lipophilicity and poor tumor accumulation limit XL-8 therapeutic application. We developed a novel XL-8 loaded with poly(D,L-lactide-co-glycolide) nanoparticles using the single emulsion-solvent evaporation method. The nanoparticles possessed high XL-8 loading content (4.6%) and encapsulation efficiency (87.7%) and a small size (182 ± 19 nm), and negative surface charge (−22.2 ± 3.8 mV) contributed to a specific intracellular accumulation. Sustained biphasic XL-8 release from nanoparticles enhanced the photosensitizer photostability upon irradiation that could potentially reduce the quantity of the drug applied. Additionally, the encapsulation of XL-8 in the polymer matrix preserved phototoxic activity of the payload. The nanoparticles displayed enhanced cellular internalization. Flow cytometry and confocal laser-scanning microscopy studies revealed rapid XL-8 loaded nanoparticles distribution throughout the cell and initiation of DNA damage, glutathione depletion, and lipid peroxidation via reactive oxygen species formation. The novel nanoformulated XL-8 simultaneously revealed a significant phototoxicity accompanied with enhanced photostability, in contrast with traditional photosensitizers, and demonstrated a great potential for further in vivo studies.