Functionalized surface of PLGA nanoparticles in thermosensitive gel to enhance the efficacy of antibiotics against antibiotic resistant infections in endodontics: A randomized clinical trial.

Enterococcus faecalis plays the key role in endodontic infections and is responsible for the formation of biofilm on dentin, which causes a resistance against periradicular lesions treatment, consequently the aim of this study is to use nanoparticles entrapping anibacterial agents coated with chitosan that in authors previous study showed a successful in vitro biofilm inhibition, additionally incorporated in thermoresponsive gel.to benefit nanoparticles` small size, and the positive charge of their surfaces that binds with the negatively charged surface of bacterial cell causing its destruction, in addition to the sustained release pattern of the drug based nanoparticles in gel. Therefore, Ciprofloxacin hydrochloride (CIP) encapsulated in PLGA nanoparticles coated with chitosan (CIP-CS-PLGA-NPs), in addition to free CIP, were incorporated in Pluronic® 407/188 to form thermosensitive gels (F1) and (F2), respectively. The thermosensitive gels were tested with regards to rheology, gelling temperature and the release pattern of the drug. A clinical study of the efficacy of F1 and F2 as antibacterial treatments was conducted on patients followed by a comparative studies against CIP and Ca(OH)2 pastes in terms of biofilm inhibition assay and total bacterial reduction count and percent.The results revealed that F1 and F2 exhibited gelation temperature of 36.9 ± 0.3 °C and 36.0 ± 0.4 °C, viscosity was 15,000 ± 360.6 and 7023.3 ± 296.8 cP respectively. The cumulative release of F1 and F2 after 72 h was 50.03% ± 0.7345 and 77.98% ± 3.122 respectively. F1 was the most efficient treatment against recurrent E.faecalis infection in endodontics that was evident by the highest total bacterial reduction count and percent and biofilm inhibition percent that were recorded in the group treated with F1followed by the group treated with F2. Nanocarriers succeeded in carrying the drug deeply in the root canal and sustaining its effect to abolish the obstinate E. faecalis recurrent infection and its biofilm formation.

Preparation of PLGA-chitosan based nanocarriers for enhancing antibacterial effect of ciprofloxacin in root canal infection.

The aim of this study is to prepare and evaluate the antibacterial and antibiofilm activity of ciprofloxacin (CIP) loaded PLGA nanoparticles (F2) and CIP-PLGA nanoparticles coated with chitosan (F3) versus ciprofloxacin solution (Fl) as a control on Enterococcus faecalis. F2 was prepared using double emulsion evaporation technique then coated with chitosan (F3). The prepared F2 and F3 were evaluated for size, surface charge, encapsulation efficiency, morphology and in vitro release. F1, F2, F3, and Chitosan (CS) were assessed in vitro using agar diffusion technique and biofilm inhibition assay. Finally, biofilm inhibition on teeth using Colony Forming Unit (CFU) was implemented with different concentrations of the three formulae. The results revealed that F2 is 202.9 nm with a negative charge -0.0254 mv, while F3 is 339.6 nm with a positive charge +28.5 mv. The encapsulation efficiency of F2, and F3 was 64% and 78% respectively. The amount released was 92.62% and 78.3% for F2 and F3, respectively, after 72 h, while F1 showed 100% released in the first hour. CS, F1, F2, and F3, showed antibacterial effect with inhibition zone of 12 mm, 22 mm, 20 mm, and 32 mm respectively. Biofilm inhibition of F1, F2, and F3 were 60%, 74%, and 91.8%, respectively. F3 colony count was less than F2, and F1 in all concentrations. It can be concluded that F3 had proven to exhibit potential antibacterial and antibiofilm activity in a controlled release pattern consequently, they can be used as an intra-canal medication.

Dermal delivery of Fe-chlorophyllin via ultradeformable nanovesicles for photodynamic therapy in melanoma animal model.

Melanoma is resistant to chemotherapeutics with poor prognosis and high potential of metastasis. Photodynamic therapy (PDT) represents a localized therapeutic modality, as cytotoxicity occurs when light activates photosensitizer (PS) at the tumour site. The aim of this study is dermal delivery of a high molecular weight hydrophilic photosensitizer (PS), ferrous chlorophyllin (Fe-CHL) via transethosomes for treatment of melanoma by PDT. Transethosomes were made of phosphatidyl choline, edge activator and 20% w/v Ethanol. They were evaluated for mean size, zeta potential, entrapment efficiency, ex-vivo permeation, localization in skin layers by transmission electron microscope (TEM), and finally, evaluated in melanoma animal model. Transethosomes of different mean vesicle size were evaluated for their skin retention and permeation through mice skin. TE of ∼500 nm (E3) being ultradeformable showed deep localization in skin confirmed by ex-vivo and TEM micrographs without permeation of PS to recipient compartment due to its size. The proposed study offers successful treatment of resistant melanoma by PDT, where complete tumour regression of small tumours occurred after single PDT, while large tumours after double PDT without recurrence for 8 months. This indicates the efficiency of nanovesicles in PS delivery and the efficiency of Fe-CHL in production of reactive oxygen species.

Liposomal delivery of ferrous chlorophyllin: A novel third generation photosensitizer for in vitro PDT of melanoma.

BACKGROUND: Cutaneous melanoma (CM) has substantially increased among Caucasian populations in the past few decades. This increased the number of CM deaths throughout the world. Pigmentation of melanoma reduces the efficacy of photodynamic therapy (PDT). Third generation photosensitizers (PSs) are characterized by improved targeting to the diseased tissue and reduced systemic side effects. This study is directed towards synthesis and characterization of liposomes encapsulating sodium ferrous chlorophyllin (Fe-CHL) and assessing its efficacy as a PS in PDT of melanoma. METHODS: Phenylthiourea (PTU) was used as a melanin synthesis inhibitor. PDT has been applied on de-pigmented melanoma cells using liposomes-encapsulated Fe-CHL. Cell death mechanisms after PDT were evaluated. RESULTS: Treatment of melanoma cells with 200µM of PTU for 48h provided 49.9% melanin inhibition without significant cytotoxicity. Transmission electron microscope (TEM) results proved an increase in the cellular uptake of liposomes by increasing incubation period from 6 to 24h via endocytosis with preferential accumulation in the mitochondria and the nucleus. Following de-pigmentation, PDT was applied resulting in LC50 of 18.20 and 1.77µM after 24 and 48h incubation with liposomes-encapsulated Fe-CHL respectively and exposure to 56.2J/cm2 monochromatic red laser of wavelength of 652nm. Mechanism of cell death of Fe-CHL mediated PDT was found to be a combination of both apoptosis and necrosis. CONCLUSIONS: Liposomes could be efficiently employed as a potential sustained release delivery system in the Fe-CHL-mediated PDT of de-pigmented melanoma.

Preparation and biopharmaceutical evaluation of tacrolimus loaded biodegradable nanoparticles for liver targeting.

Tacrolimus (TAC) is a potent immunosuppressant used in liver transplantation. Its use is however hindered by its systemic side effects, mainly nephrotoxcity. Since antigen presentation occurs in the graft and lymphatics, then by targeting TAC to the liver and spleen graft survival and decreased side effects could both be achieved. Simultaneous targeting to liver and spleen could be obtained via the reticuloendothelial system (RES). The objective of this study was to formulate RES attractive TAC-loaded nanoparticles that could ultimately increase TAC concentration in the liver and spleen and decrease it in the kidneys. Tacrolimus was incorporated into Poly(lactic acid) nanoparticles via the emulsion-solvent evaporation method. Poly lactide tacrolimus nanoparticles (PLA-TAC-NP) were extensively characterized by dynamic light scattering (DLS), transmission, scanning and atomic force microscopy (TEM, SEM and AFM) ensuring that they possessed the required characteristics rendering them RES attractive. Targeting efficiency of the formulated particles was assessed in-vitro by the evaluating their uptake by cultured human monocytes both qualitatively by TEM and quantitatively by HPLC-UV. DLS showed that particles had a mean diameter of 255 +/- 4.58 nm with unimodal distribution. Results were confirmed by SEM, AFM and TEM. Zeta Potential was -60.08 +/- 5.83 mV, whereas entrapment efficiency was 64.71 +/- 4.27%. TAC release pattern from PLA-NP was determined by the dialysis bag method showing 77 +/- 45.72% drug release within 4 days. PLA-TAC-NP phagocytosis was confirmed by TEM. The extent of phagocytosis was determined by HPLC analysis to be 80.48 +/- 11.61%. In conclusion, PLA-TAC-NP are promising carriers for TAC targeting to the liver and spleen via the reticuloendothelial system (RES).

Evaluation of hybrid liposomes-encapsulated silymarin regarding physical stability and in vivo performance.

Silymarin, a known standardized extract obtained from seeds of Silybum marianum is used in treatment of liver diseases of varying origins. Aiming at improving its poor bioavailability from oral products, silymarin hybrid liposomes are introduced in this work for buccal administration after investigating their stability and in vivo hepatoprotective efficiency. Silymarin loaded hybrid liposomes composed of lecithin (L), cholesterol (Ch), stearyl amine (SA) and Tween 20 (T20) in molar ratio of (9:1:1:0.5) were prepared. Their stability upon storage was studied at 4 degrees C and at ambient conditions. Stored samples were analyzed for percent encapsulation, drug release, particle size, turbidity measurement and visual changes. Characterization of the blend between phospholipid and silymarin was done using FT-IR and DSC which indicated a possible interaction. The stabilized formula of silymarin hybrid liposomes was evaluated upon buccal administration regarding its hepatoprotective activity against carbon tetrachloride-induced oxidative stress in albino rats. The degree of protection was measured using biochemical parameters like serum glutamic oxalacetate transaminase (SGOT) and serum glutamic pyruvate transaminase (SGPT). The introduced silymarin hybrid liposomes produced a significant decrease in both transaminase levels when challenged with CCl(4) (intraperitonially) in comparison with orally administered silymarin suspension. This improvement was also confirmed histopathologically.