A surface science perspective on TiO2 photocatalysis

Discrete particle simulation of particulate systems: A review of major applications and findings

Targeted delivery combined with controlled drug release has a pivotal role in the future of personalized medicine. This review covers the principles, advantages, and drawbacks of passive and active targeting based on various polymer and magnetic iron oxide nanoparticle carriers with drug attached by both covalent and noncovalent pathways. Attention is devoted to the tailored conjugation of targeting ligands (e.g., enzymes, antibodies, peptides) to drug carrier systems. Similarly, the approaches toward controlled drug release are discussed. Various polymer–drug conjugates based, for example, on polyethylene glycol (PEG), N-(2-hydroxypropyl)methacrylamide (HPMA), polymeric micelles, and nanoparticle carriers are explored with respect to absorption, distribution, metabolism, and excretion (ADME scheme) of administrated drug. Design and structure of superparamagnetic iron oxide nanoparticles (SPION) and condensed magnetic clusters are classified according to the mechanism of noncovalent drug loading involving...

Targeted Drug Delivery with Polymers and Magnetic Nanoparticles: Covalent and Noncovalent Approaches, Release Control, and Clinical Studies.

Photocatalytic oxidation for indoor air purification: a literature review

Photocatalytic construction and building materials: From fundamentals to applications

Preparation of chitosan particles suitable for enzyme immobilization.

The effects of initial NO concentration, gas-residence time, reaction temperature and ultraviolet (UV) light intensity on the photocatalytic decomposition of NO have been determined in an annular flow-type and a modified two-dimensional fluidized-bed photoreactors. The decomposition of NO by photocatalysis increases with decreasing initial NO concentration and increasing gas-residence time. The reaction rate increases with increasing UV light intensity. The light transmission increases exponentially with the bed voidage at superficial gas velocity above 1.3 times the minimum fluidizing velocity ( U mf ) in the two-dimensional fluidized-bed photoreactor. In the two-dimensional fluidized-bed photoreactor, NO decomposition reaches >70% at the gas velocity of 2.5  U mf . A two-dimensional fluidized-bed photoreactor is an effective tool for high NO decomposition with efficient utilization of photon energy.

Photocatalytic decomposition of NO by TiO2 particles

Influences of process parameters were investigated on the efficiency of encapsulation of bovine serum albumin (BSA) in poly( dl -lactic-co-glycolic acid) (PLGA) nanoparticles produced by w1/o/w2 (water-in-oil-in-water) double emulsion-solvent evaporation method. According to a 5-factorial 3-level Box–Behnken type experimental design aqueous solution of BSA was emulsified in an immiscible organic phase composed of dichloromethane and various quantities of dissolved PLGA to get water-in-oil (w1/o) emulsion. This latter was then dispersed in a second aqueous phase (w2) containing poly-vinyl-alcohol (PVA) surfactant as an emulsifier/stabilising agent. PLGA nanoparticles with encapsulated BSA were obtained by evaporating the dichloromethane from the w1/o droplets. Encapsulation efficiency was determined as the weight ratio of BSA remained in the PLGA nanoparticles relative to the total weight of BSA used in the process. By statistical evaluation of the experimental results an equation was proposed to predict the encapsulation efficiency as a function of five process variables. Two optimization procedures were carried out to increase the efficiency of encapsulation, with and without constraints referring to the required mean particle size. Correlation was found between the latter and the achievable maximal encapsulation efficiency under optimal process conditions.

Optimization of protein encapsulation in PLGA nanoparticles

Comparison of the preparation of PLGA–BSA nano- and microparticles by PVA, poloxamer and PVP

Investigation was carried out to determine the influence of process conditions on the volume mean size of PLGA nanoparticles intended as drug delivery vehicle for an injection formula of protein type therapeutic agent. Nanoparticles were produced by double emulsion-solvent evaporation method to encapsulate bovine serum albumin into the PLGA matrix material. At first aqueous BSA solution was dispersed by sonication into an organic phase composed of dichloromethane as solvent and dissolved PLGA. This first emulsion was dispersed in a second aqueous phase containing PVA emulsifier. Solid nanoparticles were obtained by evaporating the dichloromethane from the droplets. Size distribution of particles was determined by dynamic light scattering. It was found that volume mean particle size was influenced by several process variables, such as PVA concentration in the external phase, PLGA concentration in the organic phase, BSA concentration in the inner phase, volume ratio of the external and intermediate phases, and the time of sonication during the second emulsification. To elucidate their effects a 5-factorial 3-level experimental design and statistical analysis were carried out. Relationship between the mean particle size and process parameters was proposed.

János Gyenis

Papers

Preparation of chitosan particles suitable for enzyme immobilization.

Photocatalytic decomposition of NO by TiO2 particles

Optimization of protein encapsulation in PLGA nanoparticles

Comparison of the preparation of PLGA–BSA nano- and microparticles by PVA, poloxamer and PVP

Influence of process conditions on the mean size of PLGA nanoparticles