Encapsulation of docetaxel in oily core polyester nanocapsules intended for breast cancer therapy

This study is designed to test the hypothesis that docetaxel [Doc] containing oily core nanocapsules [NCs] could be successfully prepared with a high percentage encapsulation efficiency [EE%] and high drug loading. The oily core NCs were generated according to the emulsion solvent diffusion method using neutral Labrafac CC and poly(d, l-lactide) [PLA] as oily core and shell, respectively. The engineered NCs were characterized for particle mean diameter, zeta potential, EE%, drug release kinetics, morphology, crystallinity, and cytotoxicity on the SUM 225 breast cancer cell line by dynamic light scattering, high performance liquid chromatography, electron microscopies, powder X-ray diffraction, and lactate dehydrogenase bioassay. Typically, the formation of Doc-loaded, oily core, polyester-based NCs was evidenced by spherical nanometric particles (115 to 582 nm) with a low polydispersity index (< 0.05), high EE% (65% to 93%), high drug loading (up to 68.3%), and a smooth surface. Powder X-ray diffraction analysis revealed that Doc was not present in a crystalline state because it was dissolved within the NCs' oily core and the PLA shell. The drug/polymer interaction has been indeed thermodynamically explained using the Flory-Huggins interaction parameters. Doc release kinetic data over 144 h fitted very well with the Higuchi model (R2 > 0.93), indicating that drug release occurred mainly by controlled diffusion. At the highest drug concentration (5 μM), the Doc-loaded oily core NCs (as a reservoir nanosystem) enhanced the native drug cytotoxicity. These data suggest that the oily core NCs are promising templates for controlled delivery of poorly water soluble chemotherapeutic agents, such as Doc

Preparation of polycaprolactone nanoparticles via supercritical carbon dioxide extraction of emulsions

Polycaprolactone (PCL) nanoparticles were produced via supercritical fluid extraction of emulsions (SFEE) using supercritical carbon dioxide (scCO2). The efficiency of the scCO2 extraction was investigated and compared to that of solvent extraction at atmospheric pressure. The effects of process parameters including polymer concentration (0.6–10% w/w in acetone), surfactant concentration (0.07 and 0.14% w/w) and polymer-to-surfactant weight ratio (1:1–16:1 w/w) on the particle size and surface morphology were also investigated. Spherical PCL nanoparticles with mean particle sizes between 190 and 350 nm were obtained depending on the polymer concentration, which was the most important factor where increase in the particle size was directly related to total polymer content in the formulation. Nanoparticles produced were analysed using dynamic light scattering and scanning electron microscopy. The results indicated that SFEE can be applied for the preparation of PCL nanoparticles without agglomeration and in a comparatively short duration of only 1 h

Measurement of the adhesion between single melamine-formaldehyde resin microparticles and a flat fabric surface using AFM

An understanding of the adhesion of microparticles, particularly microcapsules, containing a functional component to a fabric surface is crucial to an effective application of this component to the fibre. Fabric surface is very rough; hence, direct measurement of the adhesion of single microparticles to surfaces with a roughness greater than the particle diameter is difficult. In the study reported here, cotton films were generated by dissolving cotton powder in an organic solvent and their properties including surface roughness, thickness, contact angle and purity were characterised. The adhesive forces between single melamineformaldehyde (MF) resin microparticles and a cotton film under ambient conditions with a relative humidity of above 40% were measured using atomic force microscopy; they are considered to be dominated by capillary forces. It was found that there was little adhesion between a MF microparticle and a cotton film in an aqueous solution of sodium dodecylbenzene sulphonate as surfactant. Repulsion between them was observed, but it reduced with increase in the surfactant concentration and decrease in the pH of the solution. The repulsion contributions are thought to originate mainly from electrostatic repulsion. It is believed that the studies on the adhesion between single MF microparticles and a cotton film under ambient conditions or dispersed in surfactant solutions, are beneficial to the attempts to enhance the adhesion of microcapsules to fabric surfaces via a modification of their surface composition and morphology

Ferrocene-loaded nanocarrier as probe for cochlear biodistribution study

Purpose: The fate of drug nanocarriers (NCs) in the inner ear remains elusive. The aim of the work is to develop ferrocene (FER)-loaded NCs to elucidate the cochlear biodistribution of such NCs. Methods: FER-NCs were prepared by surfactant free solvent-diffusion technique using a mixture of PLGA/PCL-PEG (ratios 1/1, 1/2) dissolved in acetone. FER-NCs were washed and freeze-dried. TEM analyses were carried out to study the FER-NC morphology. Lactose, mannitol, sucrose were tested at different cryoprotectant/nanocarrier ratios (0/1, 1/1, 3/1, 5/1) to stabilize FER-NCs during freeze-drying. The stability of the FER-NCs was checked by measuring particle size and zeta potential (ZP) immediately after water dispersion and after 12 days. FER-NCs were placed in the round window (RW) niche of the middle ear in guinea pigs. After 48 hours, the animals were sacrificed, the cochlea isolated and prepared for TEM. Results: The Ferrocene-loaded NCs had a mean diameter of 201.2\ub157.7, PDI of 0.328\ub10.074 and ZP of -20.2\ub14.8mV. PLGA/PCLPEG NCs of 1/2 allowed higher EE% (85.50\ub111.15) than ones made with 1/1 ratio (42.93\ub13.65). The FER-NCs appeared spherical with smooth surface. All cryoprotectants increased RES-NCs stability during the freeze-drying process. However, lactose, especially when used in 3/1 ratio, was more effective than other ones after dispersion and during 12-day stability studies. FER-NCs crossed the RW membrane and were found adjacent or in the cells lining the scala tympani of the cochlea. Hearing was normal after RW placement of NCs. Conclusion: FER-NCs were successfully prepared by emulsion-diffusion technique and the 1/2 PLGA/PLC-PEG ratio was selected in term of best encapsulation efficiency. Moreover, lactose (3/1 cryoprotectant/NCs ratio) guaranteed FER-NCs stability during freeze-drying process and maintained FER-NCs stable in suspension for at least 12 days. When placed into the RW niche, FER-NCs enter the cochlea and do not appear to cause hearing loss