Spawning Performance and Sex Steroid Levels in Female Pikeperch Sander lucioperca Treated with Poly(lactic-co-glycolic acid) Microparticles.

Pikeperch Sander lucioperca is a piscivorous species considered a promising candidate for the diversification of intensive aquaculture. This study aimed to determine the effect of a sustained-release delivery system incorporating mammalian gonadotropin-releasing hormone agonist (mGnRHa) into poly(lactic-co-glycolic acid) (PLGA) microparticles on the sex steroid levels and aspects of artificial reproduction of pikeperch. Fish were divided into four groups and injected with 20 µg mGnRHa/kg, 5-day release microparticles encapsulated with 5 µg GnRHa/kg BW (PLGA 5), 20 µg GnRHa/kg (PLGA 20), or 1 mL/kg 0.9% NaCl (control). Cumulative percentage ovulation was 100% in the PLGA 5 group, significantly higher than in other tested groups. No differences among groups were observed in latency or fecundity. The level of 11-ketotestosterone (11-KT) peaked at 40 h post-injection, and was sustained during ovulation, in all treated groups. The 17ß-estradiol (E2) concentration increased in the mGnRHa-only group immediately after hormone injection, while both PLGA groups showed a reduction in E2 after injection, continuing to decrease until ovulation. A low dose of mGnRHa in PLGA microparticles significantly improves induction of ovulation and results in acceptable reproductive performance, which may positively affect pikeperch production under controlled conditions.

Use of droplet-based microfluidic techniques in the preparation of microparticles.

Microparticles are widely used in myriad fields such as pharmaceuticals, foods, cosmetics, and other industrial fields. Compared with traditional methods for synthesizing microparticles, microfluidic techniques provide very powerful platforms for creating highly controllable emulsion droplets as templates for fabricating uniform microparticles with advanced structures and functions. Microfluidic techniques can generate emulsion droplets with precisely controlled size, shape, and composition. A more precise preparation process brings an effective tool to control the release profile of the drug and introduces an easily accessible reproducibility. The paper gives information about basic droplet-based set-ups and examples of attainable microparticle types preparable by this method.

Use of droplet-based microfluidic techniques in the preparation of microparticles.

Microparticles are widely used in myriad fields such as pharmaceuticals, foods, cosmetics, and other industrial fields. Compared with traditional methods for synthesizing microparticles, microfluidic techniques provide very powerful platforms for creating highly controllable emulsion droplets as templates for fabricating uniform microparticles with advanced structures and functions. Microfluidic techniques can generate emulsion droplets with precisely controlled size, shape, and composition. A more precise preparation process brings an effective tool to control the release profile of the drug and introduces an easily accessible reproducibility. The paper gives information about basic droplet-based set-ups and examples of attainable microparticle types preparable by this method.

Preformulation design of PLGA particulate system for multi-day drug delivery of the antidepressant mirtazapine.

In this experimental study, the biodegradable polylactide-co-glycolide (PLGA) microparticles (MP) loaded with the insoluble antidepressant mirtazapine were prepared by the simple o/w solvent evaporation method. The formation involved intrinsic variables, such as the content of polymer (700, 900 or 1200 mg), dichloromethane (5 or 10 ml) and/or drug (200 or 400 or 600 mg), and the volume of the aqueous emulsion phase (400, 600 or 800 ml). The influence of these parameters on the size and morphology of microparticles, encapsulation efficiency, and drug release behavior was observed. All MP were successfully prepared, and their size ranged between 165.34 ± 42.88 and 360.17 ± 121.59 μm. MP exhibited prolonged drug release (days), and some profiles had multiphasic character. It was found that the samples prepared with a  higher initial amount of PLGA were bigger with prolonged lag time up to 34.3 hours. On the other hand, higher drug concentrations reduced the lag time. The external phase volume reduction and multiplication of dichloromethane amount prolonged the mirtazapine release and decreased the encapsulation efficiency. These observations were further confirmed by multivariate data analysis.