Confocal Laser Scanning Microscopy Studies Research Articles

Topical delivery of fluocinolone acetonide integrated NLCs and salicylic acid enriched gel: A potential and synergistic approach in the management of psoriasis

Psoriasis is a chronic autoimmune inflammatory disease of the skin that tends to affect around 2–3% of the global population. As a cascade of events occurs concurrently during psoriasis pathogenesis, treatment with a therapeutic combination is primarily concerned. The conventional formulation containing a combination of anti-inflammatory corticosteroid and the keratolytic agent is frequently employed for topical therapy of psoriasis, but their efficacy remains low. Therefore, the present work aimed to explore the efficacy of Fluocinolone Acetonide (FA) loaded NLCs and plain Salicylic Acid (SA) containing novel gel (FSG) for effective management of psoriasis. For comparative study plain FA, and SA containing conventional gel (PFSG) formulation was also prepared. The FSG formulation exhibited prolonged release of FA for more than 24 h, whereas the PFSG formulation released more than 90% of FA within 7 h. Ex-vivo permeation study revealed negligible absorption of drugs into the systemic circulation from both the FSG and PFSG formulations; nevertheless, the dermal pharmacokinetic investigation revealed significantly higher (P < 0.05) retention of FA from FSG formulation as compared to PFSG formulation. Confocal laser scanning microscopic study confirmed strict confinement of FA loaded NLCs to the epidermal and deep dermal layer of the skin whereas PFSG was largely restricted to the outer layer of skin. No skin irritation was reported in vivo, upon topical application of FSG formulation, whereas slight irritation was reported for PFSG formulation. Results of histopathological studies proposed that FSG could effectively alleviate the psoriatic manifestations in the IMQ prompted model. This examination was additionally aligned with PASI scoring. Further, the findings of the ELISA study revealed that the FSG significantly reduced the concentration of prime pathogenic cytokines (TNF-α, IL-17, and IL-22) as compared to PFSG and IMQ groups. Thus, the overall findings suggest greater efficacy of nanocarrier enriched gel formulation than plain gel formulation.

Microleakage Assessment of Two Different Pit and Fissure Sealants: A Comparative Confocal Laser Scanning Microscopy Study.

IntroductionPit and fissures of permanent dentition are considered to be highly vulnerable to the adhesion of cariogenic microorganisms and consequently result in caries formation. The main problem associated with sealant failure will be microleakage. Therefore, sealants can be considered to be an effective preventive procedure for dental caries, only if it strongly bonds to the tooth, and protect the pit and fissures from the oral bacterial environment.Aim and objectiveTo compare and assess the microleakage of two different pit and fissure sealants on permanent molars.Materials and methodsA total of 20 extracted third molars were randomly divided into two groups where group I is conventional sealant and group II is hydrophilic sealant. Occlusal surfaces of permanent molars were treated with 37% orthophosphoric acid before sealant placement. Tooth samples were subjected to 0.1% rhodamine dye immersion, thermocycling, and tooth samples were sectioned and evaluated under a confocal laser microscope for dye penetration. A non-parametric test (Mann–Whitney U) was performed to compare the mean microleakage score difference between the groups.ResultsGroup II (hydrophilic sealant) showed a minimum level of the microleakage score when compared to group I (conventional sealant) and was found to be statistically significant using the Mann-Whitney U test with a p value <0.05.ConclusionThe less the microleakage, the better will be the retention of the sealant for a longer duration and cariostatic action.How to cite this articlePrabakar J, Indiran MA, Kumar P, et al. Microleakage Assessment of Two Different Pit and Fissure Sealants: A Comparative Confocal Laser Scanning Microscopy Study. Int J Clin Pediatr Dent 2020;13(S-1):S29–S33.

Ability of Sodium Hypochlorite to Clean Dentinal Tubules by Manual or Sonic Activation at Varying Temperature: A Confocal Laser Scanning Microscopic Study

Ability of Sodium Hypochlorite to Clean Dentinal Tubules by Manual or Sonic Activation at Varying Temperature: A Confocal Laser Scanning Microscopic Study

Effect of C/N substrates for enhanced extracellular polymeric substances (EPS) production and Poly Cyclic Aromatic Hydrocarbons (PAHs) degradation.

Extracellular Polymeric Substances (EPS) influenced Poly Cyclic Aromatic Hydrocarbons (PAHs) degrading Klebsiella pneumoniae was isolated from the marine environment. To increase the EPS production by Klebsiella pneumoniae, several physicochemical parameters were tweaked such as different carbon sources (arabinose, glucose, glycerol, lactose, lactic acid, mannitol, sodium acetate, starch, and sucrose at 20g/L), nitrogen sources (ammonium chloride, ammonium sulphate, glycine, potassium nitrate, protease peptone and urea at 2g/L), different pH, carbon/nitrogen ratio, temperature, and salt concentration were examined. Maximum EPS growth and biodegradation of Anthracene (74.31%), Acenaphthene (67.28%), Fluorene (62.48%), Naphthalene (57.84%), and mixed PAHs (55.85%) were obtained using optimized conditions such as glucose (10g/L) as carbon source, potassium nitrate (2g/L) as the nitrogen source at pH 8, growth temperature of 37°C, 3% NaCl concentration and 72h incubation period. The Klebsiella pneumoniae biofilm architecture was studied by confocal laser scanning microscopy (CLSM) and scanning electron microscope (SEM). The present study demonstrates the EPS influenced PAHs degradation of Klebsiella pneumoniae.

Antischistosomal properties of aurone derivatives against juvenile and adult worms of Schistosoma mansoni

Schistosomiasis is a neglected disease caused by helminth flatworms of the genus Schistosoma, affecting over 240 million people in more than 70 countries. The treatment relies on a single drug, praziquantel, making urgent the discovery of new compounds. Aurones are a natural type of flavonoids that display interesting pharmacological activities, particularly as chemotherapeutic agents against parasites. In pursuit of treatment alternatives, the present work conducted an in vitro and in vivo antischistosomal investigation with aurone derivatives against Schistosoma mansoni. After preparation of aurone derivatives and their in vitro evaluation on adult schistosomes, the three most active aurones were evaluated in cytotoxicity and haemolytic assays, as well as in confocal laser-scanning microscope studies, showing tegumental damage in parasites in a concentration-dependent manner with no haemolytic or cytotoxic potential toward mammalian cells. In a mouse model of schistosomiasis, at a single oral dose of 400 mg/kg, the selected aurones showed worm burden reductions of 35% to 65.0% and egg reductions of 25% to 70.0%. The most active thiophenyl aurone derivative 18, unlike PZQ, had efficacy in mice harboring juvenile S. mansoni, also showing significant inhibition of oviposition by parasites, giving support for the antiparasitic potential of aurones as lead compounds for novel antischistosomal drugs.

Buspirone loaded solid lipid nanoparticles for amplification of nose to brain efficacy: Formulation development, optimization by Box-Behnken design, in-vitro characterization and in-vivo biological evaluation

The strategies to avoid blood brain barrier are been explored to improve brain targeting therapeutics in order to ensure potential prospects of nose to brain delivery. In this research work, Buspirone (BUS) loaded solid lipid nanoparticles (SLNs) for nose to brain delivery were prepared by solvent free technique and optimized by three factors and three levels Box- Behnken design. The three independent variables viz, drug (BUS) to lipid (Compritol® 888 ATO) ratio (labeled A), surfactant concentration (tween 80+ poloxamer, 2:1- labeled B) and sonication time (labeled C) were selected in range of 1:3–1:5, 1–2% and 5–15 min respectively. Their influences on particle size (nm, labeled Y1), Polydispersity index (PDI, labeled Y2) and % entrapment efficiency (labeled Y3) were observed. Optimized batch (B-OP3) showed spherical morphology possessing the value of particle size, PDI, zeta potential, entrapment efficiency, and in-vitro drug release as 218.60 ± 9.18 nm, 0.305 ± 0.012, −26.47 ± 2.36 mV, 70.13 ± 4.21% and 93.36 ± 8.63% respectively. BUS-SLNs displayed superior ex-vivo permeation profiles as compared to BUS-Sol. X-ray diffraction and differential scanning calorimetry spectra do not display the characteristic peak of BUS, thus recommending the entrapment of drug in lipid core. AUC 0-∞ in the brain for BUS-SLNs i.n was found to be 2.18 times more than BUS-Sol i.n and 2.66 times more than BUS-SLNs i.v., thus supporting improved targeting efficiency of developed SLNs. The value of drug targeting efficiency (DTE) percentage to brain (882.59%) and nose to brain direct transport (DTP) percentage (88.67%) for BUS-SLNs i.n was higher as compared to BUS-Sol i.n (DTE = 238.63%, DTP = 58.09%). Furthermore, confocal laser scanning microscopy study confirmed that brain targeting of BUS-SLNs was better than BUS-Sol when administered intranasally. Finally, results revealed that SLNs establish itself as a potential drug delivery system for brain delivery of BUS via intranasal route.

Physical techniques shed light on the differences in sugarcane bagasse structure subjected to steam explosion pretreatments at equivalent combined severity factors

Significant improvements in pretreatments and a deeper understanding of changes in the physical structure and chemical composition of pretreated lignocellulosic materials are required to guarantee the technical and economic sustainability of second-generation ethanol technologies. In present work, several biophysical techniques were applied to characterize sugarcane bagasse samples that have been subjected to autocatalytic, phosphoric acid and sulfuric acid catalyzed steam explosion under equivalent combined severity factors (CSF). Confocal laser scanning microscopy and fluorescence lifetime imaging studies demonstrated unequal changes in lignin distribution in the plant cell wall that could be nicely correlated with substrate susceptibility to enzymatic hydrolysis. Furthermore, solid state nuclear magnetic resonance corroborated these observations by showing the differences in biomass composition primarily associated with hemicellulose removal, whereas X-ray diffraction analysis revealed changes in crystallinity indexes and average crystallite sizes. Thus, the impact of pretreatment temperature on the physical structure and chemical composition of CSF-equivalent steam-exploded sugarcane bagasse was identified as the key factor for developing substrate accessibility. This calls for caution in using combined severity factor as a chief parameter for comparison of different pretreatment conditions.

Fluorescence Imaging of Mammalian Cells with Cationic Conjugated Polyelectrolytes

AbstractFluorescence imaging using poly(phenylene ethynylene) (PPE) based conjugated polyelectrolytes (CPEs) has garnered considerable attention in the recent past due to their remarkable photophysical properties. In this report, we studied the fluorescence imaging properties of a set of six PPE‐based CPEs appended with side chains varying in structure and number of cationic charges. The photophysical and aggregation features of the CPEs depend on the overall charge density on the polymer in water. The cytotoxicity of the CPEs was evaluated against MCF‐7 mammalian cells, which revealed that polyelectrolytes with less cationic charge are less cytotoxic and vice versa. Confocal laser scanning microscopy (CLSM) studies showed that all the CPEs could efficiently penetrate into the MCF‐7 cells after 10 h of incubation. The transit of CPEs into the lysosomes was confirmed by comparison with the uptake of LysoTracker Red DND‐99 dye, which also revealed that the polyelectrolytes are highly photostable. We also demonstrated that the imidazolium‐functionalized CPEs could selectively stain bacteria over mammalian cells, suggesting the importance of CPEs for clinical applications.

Tailoring of berberine loaded transniosomes for the management of skin cancer in mice

Dermal products are essential categories of drug delivery systems, and their application is getting more common. The reason for preparing transniosomes (TN) was to enhance the permeability of berberine (BBR) and to deliver the encapsulated BBR specifically to a localized area of the skin. The TN exhibited higher efficacy than the niosomes in terms of skin penetration and incorporation of TN into gel could also upsurge the thickness of formulation and thereby promote the residence phase of optimized formulation at the application site. The goal of the present research was to optimize TN for accentuated dermal delivery of BBR. The optimization of BBR-loaded TN was done using the “Box–Behnken design”. The optimized formulation was characterized for vesicles size, entrapment efficiency (%) and in vitro BBR release. Additionally, transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM) and dermatokinetic study were performed for further evaluation of BBR-loaded optimized TN formulation. The optimized BBR-TN formulation presented sealed lamellar shaped vesicles, with vesicles size of 74.05 ± 1.55 nm, entrapment efficiency of 82.54 ± 0.54% and in vitro release of 61.44 ± 1.97%. The obtained CLSM images of mice's skin clearly exemplified that the rhodamine B-loaded TN gel disseminated to deeper layer than the control (rhodamine B-hydroethanolic solution). Further, the BBR-TN gel treated mice skin showed CSkin max and AUC0-t of 132.23 μg/cm2 (epidermis) and 683.07 μg/cm2h (epidermis) in comparison to CSkin max and AUC0-t of 59.86 μg/cm2 (epidermis) and 321.41 μg/cm2h (epidermis) presented by BBR conventional gel. The in-vivo study showed that the BBR-TN gel pre-treatment mitigates the tumor multiplicity and prevented the tumor size growth in mice. Further the BBR-TN gel formulation found to be safer for skin application as depicted by skin irritation study performed on mice. The present investigation validated that the prepared TN is a valuable drug carrier system for dermal delivery of BBR for the management of skin cancer in animal model.

Morphological transition of M. tuberculosis and modulation of intestinal permeation by food grade cationic nanoemulsion: In vitro-ex vivo-in silico GastroPlus™ studies

The study aimed to investigate rifampicin (RIF) loaded cationic nanoemulsion (NE) for increased efficacy, facilitated intestinal permeability and GastroPlus™ based prediction. Formulations were prepared and characterized for robustness to dilution, cloud point and stability to varied pH. Morphological transition of M. tuberculosis H37 Rv was studied by a transmission electron microscopy (TEM), % inhibition study and cytoplasmic content analysis. The ex vivo permeation and confocal laser scanning microscopy (CLSM) studies were conducted using duodenum, jejunum and ileum. Results of robustness ensured stability to dilution, pH and temperature (˃ 37 °C). The Smix (surfactant to co-surfactant) ratio (2:1 and 3:1) possessed maximized % inhibition due to LAB and AC8. The Peff values of cationic NE were 2.25, 1.96 and 2.0 fold higher than DS (drug solution) for duodenum, jejunum and ileum, respectively, whereas enhancement ratios were 2.25-, 1.94- and 2.0 fold higher than DS. A CLSM showed 3.22-, 2.89-, and 1.1 fold higher % fluorescence intensity from duodenum, jejunum and ileum, respectively. GastroPlus™ predicted 100% regional absorption of RIF-cationic NE and considerable effect of globular size, permeability and nanonization on pharmacokinetics (PK) parameters. Conclusively, the cationic NE can be a promising approach for increased efficacy of RIF and augmented oral absorption to control tuberculosis.

Effect of Molybdenum on Pit Initiation Rate and Pit Growth Using Electrochemical Noise and Its Correlation with Confocal Laser Scanning Microscopic Studies

The effect of Mo concentration on pit initiation rate and pit growth in austenitic stainless steels (SS) were investigated by electrochemical noise (EN) and confocal laser scanning microscopy (CLSM) techniques for the first time. We used 304LN, 316LN and 317LN containing different concentrations of Mo (0.02, 2.53 and 3.58 wt.%) for our studies. Using EN technique, initiation of pits and growth of pits were analyzed using Weibull and Gumbel distribution function, respectively. Pit depth was obtained using CLSM and the correlation between pit aspect ratio and Mo concentration were studied. Weibull probability plots showed that the Mo present in the alloy reduces the pit generation rates and improves the passivity. The plot for the pit size distribution using Gumbel distribution function showed the lowest metastable pit in 317LN and the highest in 304LN, suggesting the improvement in the pitting corrosion resistance due to Mo addition. The CLSM imaging showed maximum pit depth for specimen 304LN and minimum for specimen 317LN SS. Specimen 316LN SS showed intermediate pit depth. The depth of the pits observed in 304LN, 316LN and 317LN ranged from 80-100 µm, 30-40 µm and 20-30 µm, respectively. Alloy 317LN containing highest Mo concentration (3.58 wt.%) showed the lowest pit aspect ratio values followed by alloy 316LN with 2.53 wt.% Mo. These results indicate that Mo present in the stainless steel helps in arresting the pit growth and improve the resistance to pitting corrosion.

Ethosome-Derived Invasomes as a Potential Transdermal Delivery System for Vardenafil Hydrochloride: Development, Optimization and Application of Physiologically Based Pharmacokinetic Modeling in Adults and Geriatrics.

AimThe aim of the current work was to develop vardenafil hydrochloride (VRD)-loaded ethosome-derived invasomes as a possible transdermal system which could be used for patients suffering from pulmonary arterial hypertension.MethodsVRD-loaded ethosomes were developed at three concentrations of phosphatidylcholine (5, 10 and 15 mg/mL) and three percentages of ethanol (20%, 30% and 40%, v/v). The best achieved VRD-loaded ethosomes (ETH9) were optimized to invasomes via incorporation of terpenes (limonene, cineole and a 1:1 mixture) at three concentrations (0.5%, 1% and 2%, v/v). All systems were evaluated for vesicle size, zeta potential, drug entrapment efficiency (EE%), cumulative drug permeated percentages after 0.5hrs (Q0.5h) and 12hrs (Q12h) and steady-state flux (Jss). The optimized system (ETH9-INV8) was further characterized for morphology, histopathology and confocal laser scanning microscopy (CLSM). Physiologically based pharmacokinetic (PBPK) modeling was employed to estimate VRD pharmacokinetic parameters from the optimized transdermal system and an oral aqueous drug dispersion, in adults and geriatrics.ResultsThe optimized invasomal system (ETH9-INV8) was characterized with spherical vesicles (159.9 nm) possessing negative zeta potential (−20.3 mV), promising EE% (81.3%), low Q0.5h (25.4%), high Q12h (85.3%) and the largest steady-state flux (6.4 µg.cm−2h−1). Following a leave-on period of 12hrs in rats, it showed minor histopathologic changes. CLSM studies proved its ability to deeply permeate rat skin. Lower Cmax values, delayed Tmax estimates and greater AUC0-24h folds in adults and geriatrics (≈ 2.18 and 1.69, respectively) were estimated following the transdermal application of ETH9-INV8 system.ConclusionETH9-INV8 is a promising transdermal system for VRD.

A Novel Method to Reveal a Ureolytic Biofilm Attachment and In Situ Growth Monitoring by Electrochemical Impedance Spectroscopy.

The formation of biofilms capable of efficiently carrying out ureolysis is of fundamental importance in several biotechnological systems such as urinary tract infections, building materials and municipal wastewater treatment. This work proposes a straightforward method for the formation of a ureolytic biofilm attached to graphite. The proposed strategy reduced the time needed to complete ureolysis to 3days instead of 16days required in suspension culture. To confirm the formation of a ureolytic biofilm, scanning electron microscopy and confocal laser scanning microscopy studies were employed ex situ. However, it is imperative to analyse the biofilm by direct non-invasive techniques. Accordingly, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) were used as in situ monitoring techniques. The reduction in OCP from - 0.01 to - 0.2V vs. Ag/AgCl and the increase in capacitance from 200 to 260μFcm-2 were related to biofilm attachment. To the best of our knowledge, this is the first time in which a ureolytic biofilm attachment has been analysed by EIS. The increase in the biomass from 0.04 to 2.81μm3μm-2 and in average thickness from 10.19 to 32.78μm was related to biofilm maturation.

Flavosomes, novel deformable liposomes for the co-delivery of anti-inflammatory compounds to skin.

Flavosomes, novel deformable liposomes for the topical delivery of anti-inflammatory compounds have been developed and characterized in this study. The carriers were prepared by incorporating flavonoids, specifically quercetin and dihydroquercetin, into transfersome and evaluated as a potential topical delivery system for meloxicam (MX), a potent hydrophobic NSAID (non-steroidal anti-inflammatory drug). Characterization of the flavosomes was conducted in terms of their vesicle size, zeta potential, entrapment efficiency and deformability index. Ex vivo skin permeation and confocal laser scanning microscopy studies demonstrated that the flavosome formulations improved the skin permeation of meloxicam compared to that for transfersomes. The dermal and transdermal delivery of meloxicam using these formulations has the potential of being a promising alternative to conventional oral delivery of non-steroidal anti-inflammatory drugs (NSAIDs) with enhanced local and systemic onset of action and reduced gastrointestinal side effects.

Novel Peptide Inhibitors of β-Catenin Effectively Suppress the Tumorigenesis of Colorectal Cancer

Aberrant β-catenin activation promotes the proliferation and survival of several types of tumor cells, including colorectal cancer (CRC) cells. Synthetic peptides are drug candidates for treating various diseases; however, peptide inhibitors of β-catenin have been rarely reported. A series of peptide inhibitors for β-catenin (F15A1–9k, F15A2–9k, and F15A3–9k) were designed and synthesized, and then used to treat human CRC cells (HT-29). Next, a series of in vitro assays, including cell counting, colony formation, flow cytometry, and Transwell assays, were performed to assess the biological effects of the peptides on CRC cells. Mouse xenograft models of HT-29 tumors were also used to evaluate the inhibitory effect of the peptide inhibitors on β-catenin expression in vivo. The inhibitory effect of the peptide inhibitors on β-catenin production was tested in a confocal laser scanning microscope study (CLSMS), and by H&E, TUNEL, and immunohistochemical (IHC) staining. The peptide inhibitors significantly reduced the viability of HT-29 cells in time- and concentration-dependent manners. Moreover, the peptide inhibitors for β-catenin significantly inhibited CRC tumorigenesis both in vitro and in vivo. Mechanistically, the peptide inhibitors for β-catenin inhibited the angiogenesis activity of HT-29 cells. When administered by itself, F15A2–9k blocked cell division, induced apoptosis, and reduced the migration and invasion capabilities of HT-29 cells, while a combination of F15A1–9k, F15A2–9k, and F15A3–9k showed even stronger inhibitory effects on HT-29 cells. In summary, the peptides designed to inhibit β-catenin demonstrated anti-tumor activity both in vitro and in vivo, suggesting their potential as therapeutic agents for treating CRC.

High frequency ultrasound mediated transdermal delivery of ondansetron hydrochloride employing bilosomal gel systems: ex-vivo and in-vivo characterization studies

Ondansetron hydrochloride (OND) suffers from rapid elimination (t1/2 = 3–4 h), moderate bioavailability (60%) and inconvenience following oral administration in emetic patients. As an alternative convenient approach, the current work explored the potential of high-frequency ultrasound (HFU) waves to promote transdermal delivery of OND via bilosomal gel systems (BGS) in an attempt to increase OND bioavailability and achieve a rapid onset of action in patients suffering from emesis. OND-loaded BGS were prepared and characterized for pH and rheologic properties. The variables influencing HFU were optimized, viz. bilosomal system: coupling-gel ratio (1:2 or 1:3), application period (5, 10 or 15 min) and (iii) ultrasound intensity (medium or high), mode (continuous or pulsed) & duty cycle (20, 50 or 100%). Ex-vivo permeation and confocal laser scanning microscopy (CLSM) studies were conducted. The best achieved BGS (BGS10-HFU) was subjected to histopathologic and pharmacokinetic studies in rats. OND-loaded BGS were shear thinning systems having tolerable pH values for skin application. The optimized HFU variables involved the utilization of a bilosomal system: coupling-gel ratio of 1:3 and the application of high intensity, continuous and 100% duty cycle ultrasound waves for 10 min. Ex-vivo permeation and CLSM studies revealed the superiority of BGS10 following HFU-pretreatment. BGS10-HFU exhibited minor histopathologic changes. Compared to an oral OND solution, BGS10-HFU system had significantly (P < 0.05) higher AUC0–24 and AUC 0–∞values. Non-significant differences between Cmax and tmax values were revealed. The best achieved system (BGS10-HFU) can increase OND bioavailability and initiate a rapid onset of action.

Development and skin penetration pathway evaluation of microemulsions for enhancing the dermal delivery of celecoxib

This study aimed to develop a microemulsion using PEG-6 Caprylic/Capric Glycerides as a surfactant to enhance the dermal delivery of celecoxib. Confocal laser scanning microscopy (CLSM) using the colocalization technique was also used to investigate the skin penetration pathway of the microemulsion. The prepared microemulsion formulations were characterized in terms of size, surface charge, size distribution and type. The celecoxib-loaded microemulsion had particle sizes ranging from 48 to 214 nm with neutral charge and significantly increased the skin penetration of celecoxib. According to the CLSM study, the microemulsion might attach to any part of the skin before releasing the entrapped drug to penetrate the tissue. The transfollicular pathway might be the major skin penetration pathway for the microemulsion, whereas the intercellular and transcellular pathways are minor ones.

Surface-modified polycaprolactone nanoparticles for the brain-targeted delivery of nevirapine

The low-density lipoprotein (LDL) receptors overexpressed in brain capillary endothelial cell (BCEC) membrane were successfully targeted by polysorbate 80 (PS80)-coated polycaprolactone (PCL) nanoparticles for brain delivery of nevirapine (NVP). The nanoparticles prepared by emulsion solvent evaporation technique were evaluated for mean particle size (nm), zeta potential (mV), percentage drug entrapment efficiency (% EE), percentage drug loading (% DL), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), transmission electron microscopy (TEM), in vitro drug release study, stability study and in vivo biodistribution study. The mean particle size (nm) of uncoated nanoparticles, NvPNPs5, and PS80-coated nanoparticles, P80NvPNPs5, were (128.43 ± 4.82) nm and (218.3 ± 7.3) nm, respectively. The SEM and TEM analysis showed small-sized (< 100 nm), spherical-shaped, smooth-surface nanoparticles with less aggregation. The zeta potential (mV) analysis showed stable nanoparticles with values (− 72.1 ± 0.00) mV, NvPNPs5; (− 16.2 ± 0.00) mV, P80NvPNPs5; (− 16.2 ± 0.00) mV, 6CFNvPNPs5; and (− 13.6 ± 0.00) mV, P806CFNvPNPs5. The FT-IR and DSC report indicated drug excipient compatibility. P80NvPNPs5 showed an in vitro drug release for 36 h and its release kinetic was best fitted in Higuchi model (R2 = 0.936). Korsemeyer Peppas model showed an anomalous non-Fickian drug release mechanism as n = 0.767. P80NvPNPs5 released NVP for 24 h in the brain with prolonged blood circulation for 48 h as compared with NvPNPs5 and free drug suspension, (p < 0.05) in in vivo biodistribution study in Swiss Wistar rat. The confocal laser scanning microscopy (CLSM) study showed uniform distribution of P80NvPNPs5 in rat BCECs for 24 h post i.v. administration. The present observation concludes the futuristic scope of P80NvPNPs5 nanoparticles for brain delivery of different antiretroviral drugs as well as other CNS active drugs to treat several CNS disorders.

Effectiveness of Various Final Irrigation Techniques on Sealer Penetration in Curved Roots: A Confocal Laser Scanning Microscopy Study.

Objective To compare the efficacy of various techniques used for final irrigation on sealer penetration in the apical one-third of curved root canals. Material and Methods. Sixty-five freshly extracted maxillary first molar teeth with mesiobuccal roots having more than 20° of root curvature were used. The root canals were instrumented and randomly divided into four experimental groups and one control group. In the 4 experimental groups, 3 ml of 17% EDTA followed by 3 ml of 5.25% NaOCl was delivered with the use of the following protocols: Group 1: manual dynamic activation (MDA), Group 2: sonic irrigation (SI), Group 3: passive ultrasonic irrigation (PUI), and Group 4: conventional needle irrigation (CI). All teeth were obturated with gutta-percha and AH Plus sealer labeled with fluorescent dye. Transverse sections at 2 mm and 4 mm distance from the root apex were examined with the aid of confocal laser scanning microscopy. Total percentage (%) and maximum depth (μm) of sealer penetration were measured. Results All the experimental groups exhibited significantly higher penetration rates than the control group at both sections (p < 0.05). However, no significant differences were found in the penetration depth and percentage among the four experimental groups evaluated at both sections (p > 0.05). Conclusion PUI, SI, and MDA did not significantly improve sealer penetration in the apical portion of curved root canals when compared to conventional needle irrigation.

Lack of relationship between epidermal denervation by capsaicin and incisional pain behaviours: A laser scanning confocal microscopy study in rats.

Spontaneous pain after surgical incision is a significant problem for most post-operative patients. Pain management that relies on opioids is hindered by numerous side effects, fuelling interest in non-opioid alternatives and multimodal approaches. Subcutaneous capsaicin infiltration has shown potential for reducing post-operative pain, but there are unanswered questions about safety and possible side effects. In adult rats, we characterized the analgesic effects of pre-operative capsaicin infiltration into the skin prior to plantar incision and assessed wound healing and epidermal innervation. The surgical site on the plantar surface of the rat hind paw was infiltrated with 1% capsaicin or vehicle 30min or 1week prior to surgical incision. Spontaneous and evoked pain behaviours were assessed. Digital images of incised hind paws were used to quantify the surface area of the wound after suture removal. Epidermal nerve fibre quantification was performed on peri-incisional tissue biopsies. Intraplantar administration of capsaicin 30min before surgical incision attenuated spontaneous pain behaviours, heat hyperalgesia, epidermal innervation, but it did not alter the rate of wound healing. Incisional pain hypersensitivity returned to baseline 2weeks post-incision, at a time when no recovery of epidermal innervation is observed. Subcutaneous infiltration of capsaicin prior to surgical incision attenuated incision-induced pain behaviours and reduced epidermal innervation around the incision site. The long-lasting epidermal denervation by capsaicin had no impact in the rate of wound healing and recovery from pain behaviours. Pre-operative capsaicin infiltration attenuated spontaneous pain-like behaviour and prevented the development of heat hyperalgesia following plantar skin incision. While capsaicin caused long-lasting and widespread loss of epidermal and dermal nerve fibres, there was no measurable impact on the rate of wound healing. Pre- or intra-operative infiltration of capsaicin into surgical sites could act as a safe prophylactic for post-operative pain and reduce the need for opioids during recovery.