Purpose: Reducing the undesirable systemic effect of photodynamic therapy (PDT) can be achieved by incorporating a photosensitizer in Microparticles (MPs). This study is devoted to the preparation of biocompatible biodegradable MPs with the inclusion of the natural photosensitizer Radachlorin (RС ) and an assessment of the possibility of their use for PDT. Methods: RC-containing MPs (RС   MPs) with poly(lactic-co-glycolic acid) copolymer (PLGA) matrix were prepared by a double emulsion solvent evaporation methods. The size and morphology of RC  MPs were surveyed using scanning electron microscopy, confocal laser scanning microscopy, and dynamic light scattering. The content of RC, its release from RC MPs, and singlet oxygen generation were evaluated by the optical spectroscopy. Cellular uptake and cytotoxic photodynamic effect of RC MPs were investigated with in vitro assays. Results: The average diameter of the prepared RC  MPs was about 2-3 μ m. The RC  MPs prepared by the water/oil/oil method had a significantly higher inclusion of RC (1. 74 μ g/mg) then RC  MPs prepared by the water/oil/water method (0. 089 μ g/mg). Exposure of the prepared RC  MPs to PDT light radiation was accompanied by the singlet oxygen generation and a cytotoxic effect for tumor cells. The release of the RC from the RC  MPs was prolonged and lasted at least two weeks. Conclusion: PLGA RC MPs were found to cause a photoactivated cytotoxic effect for tumor cells and can be used for local application in PDT of tumors.

In this study, two-dimensional simulations are performed to separate polystyrene (PS) and polymethyl methacrylate (PMMA) particles suspended in water using an acoustic field. The acoustic waves are generated by two aluminum interdigitated transducers (IDTs) over a piezoelectric substrate. The effect of input power, inlet flow rate, acoustic frequency, and distance between IDTs and channels on separation efficiency is evaluated by considering channel thickness. It is observed that the separation efficiency is enhanced by increasing acoustic frequency and input power. Also, as the inlet flow rate and distance between IDTs and channel decrease, the separation efficiency increases. The optimum values for input power, flow rate, frequency, and distance are 1. 4 W, 0. 2 mL/min, 5 MHz, and 75 µm, respectively, and a maximum separation of 88% is achieved.

Background: The ability of supercritical fluids (SCFs), such as carbon dioxide, to dissolve and expand or extract organic solvents and as result lower their solvation power, makes it possible the use of SCFs for the precipitation of solids from organic solutions. The process could be the injection of a solution of the substrate in an organic solvent into a vessel which is swept by a supercritical fluid. The aim of this study was to ascertain the feasibility of supercritical processing to prepare different particulate forms of fluticasone propionate (FP), and to evaluate the influence of different liquid solvents and precipitation temperatures on the morphology, size and crystal habit of particles. Method: The solution of FP in organic solvents, was precipitated by supercritical carbon dioxide (SCCO2) at two pressure and temperature levels. Effects of process parameters on the physicochemical characteristics of harvested Microparticles were evaluated.Results: Particle formation was observed only at the lower selected pressure, whilst at the higher pressure, no precipitation of particles was occurred due to dissolution of FP in supercritical antisolvent. The micrographs of the produced particles showed different morphologies for FP obtained from different conditions. The results of thermal analysis of the resulted particles showed that changes in the processing conditions didn’t influence thermal behavior of the precipitated particles.Evaluation of the effect of temperature on the size distribution of particles showed that increase in the temperature from 400C to 500C, resulted in reduction of the mean particle size from about 30 μm to about 120m.Conclusion: From the results of this study it may be concluded that, processing of FP by supercritical antisolvent could be an approach for production of diverse forms of the drug and drastic changes in the physical characteristics of Microparticles could be achieved by changing the type of solvent and temperature of operation.

Background: There are contradictions about the immune modulating properties of chitin in comparison with chitosan. To respond to these contradictions, we investigated stimulatory effects of chitin micro-particles in comparison with chitosan micro-particles on L.major infected cell suspensions.Materials and methods: In this experimental study, Balb/c mice were intradermally infected with 2´105 stationary phase of L.major promastigotes into their base of the tail. Two weeks later infectivity were confirmed by PCR then leishmania infected lymph nodes cell suspensions of the mice were isolated. Chitin micro-particles were prepared by sonication and passing the filter and after size determination by mastersizer, used for cell stimulation. Finally, ELISA measured concentrations of TNF-a and IL-10 in cell culture supernatants.Results: We observed chitin micro-particles significantly increase TNF-a and also IL-10 production (P ≤0.001) in compare with chitosan.Conclusion: Chitin micro-particles can stimulate production of TNF-a and IL-10 in leishmania infected cell suspensions. Chitin seems to be utilized as an immunomodulator in Leishmania vaccine or treatment.

Background: Glibenclamide is a lipophilic drug widely used in type 2 diabetes treatment. However, its low bioavailability limits its use. Thus, novel formulations should be applied to improve the drug’ s bioavailability. Objectives: This study aimed to develop alternative carriers for oral delivery of glibenclamide. For this purpose, two biocompatible polymers, poly(e-caprolactone) and poly(butylene adipate) were formulated as Microparticles (MPs) capable of loading the antidiabetic drug. Methods: In this regard, as microparticle fabrication approach, the modified emulsion solvent evaporation method was applied. Physicochemical evaluation of the prepared Microparticles included the examination of their morphology, degradation rate, and thermal properties. Drug entrapment, drug loading, and particle size were also investigated. Simulated intestinal medium and body fluid at 37oC were selected as dissolution media. Differential scanning calorimetry was used to investigate the crystal properties of the Microparticles and drugs. Results: The developed Microparticles had sizes between 0. 5 and 4 μ m. Poly(butylene adipate) based Microparticles had a smooth surface, whereas poly(ε-caprolactone) based Microparticles showed a porous surface. The DSC thermogram revealed the amorphization of the drug. Hydrolysis results exhibited a very low mass loss, while in vitro release results depicted that the dissolution rate of the prepared Microparticles was higher than that of pure glibenclamide demonstrating a prolonged pattern which is ideal for minimizing the daily dose of glibenclamide. Conclusion: In this study, novel carriers for glibenclamide were successfully prepared with promising future use.