Preparation, Characterization and Evaluation of Drug Release Properties of Simvastatin-loaded PLGA Microspheres

Abstract Microspheres formulated from poly (D, L-lactic-co-glycolide) (PLGA), a biodegradable polymer, have been extensively evaluated as a drug delivery system. In this study, the preparation, characterization and drug release properties of the PLGA microspheres were evaluated. Simvastatin (SIM)-loaded PLGA microspheres were prepared by oil-in-water emulsion/solvent evaporation method. The microspheres were then frozen to −80 °C, they were freeze dried for 24 h. Characterization of SIM-loaded PLGA microspheres was evaluated by X-ray diffraction analysis, Fourier transform infrared spectroscopy analysis, and scanning electron microscopy (SEM). Drug release potential was evaluated by UV-spectrophotometry. The experimental results revealed that SIM-loaded PLGA microspheres can be successfully obtained through solvent evaporation method with appropriate morphologic characteristics and high encapsulation efficiency. The drug release pattern from polymeric microspheres in the phosphate buffered saline medium was measured during a 21-day period using UV-spectrophotometry. The correlation coefficient value (r 2 = 0.9878) of the trend lines of the graph showed that the SIM-loaded PLGA microspheres best fit with zero order release pattern. No burst release was observed with polymeric matrix. The drug release characteristic of the microspheres ascertained that the release was about 27% for SIM-loaded microspheres, which occurred within the first 6 days after maintaining the microspheres in phosphate buffer saline. Also, the microspheres successfully presented a slow release and the duration of the release lasted for more than 21 days. It can be concluded that SIM-loaded PLGA microspheres hold great promise for using as a drug-delivery system in biomedical applications, especially in drug delivery systems and tissue engineering

Encapsulation of irinotecan in polymeric nanoparticles: Characterization, release kinetic and cytotoxicity evaluation

Objective(s): Irinotecan is a potent anti-cancer drug from camptothecin group which inhibits topoisomerase I. Recently, biodegradable and biocompatible polymers such as poly lactide-co-glycolides (PLGA) have been considered for the preparation of nanoparticles (NPs). Materials and Methods: In this study, irinotecan loaded PLGA NPs were fabricated by an emulsification/solvent diffusion method to improve the efficacy of irinotecan. The effect of several parameters on the NPs’ characteristics was assessed, including the amount of drug and polymer, the amount and volume of the poly vinyl alcohol as a surfactant, and also the internal-phase volume/composition. The irinotecan entrapment efficiency and the particle size distribution were optimized by changing these variables. The cytotoxicity of the particles was evaluated by cell viability assay.Results: NPs were spherical with a comparatively mono-dispersed size distribution and negative zeta potential. Selected formulation (S9) showed suitable size distribution about120 nm with relative high drug entrapment. MTT assay showed a stronger cytotoxicity of S9 against HT-29 cancer cells than control NPs and irinotecan free drug. The release kinetic indicated Log-Probability model in S9.Conclusion: Our results demonstrated that the designed NPs show suitable characteristic and also great potential for further in vivo cancer evaluation

An anti-inflammatory Glyburide-loaded nanoghost for atherosclerosis therapy: A red blood cell based bio-mimetic strategy

Inflammation control is becoming a critical strategy for atherosclerosis management, because inflammation is involved in plaque progression. In this regard, a biomimetic strategy using cell membrane-coated nanoparticles has some promising advantages. In the study, a RBC membrane-based nanoghost containing Glyburide (Glibenclamide) was prepared using an extrusion method. The hydrodynamic size and zeta potential of the nanoghost were changed compared to PLGA nanoparticles. In addition, a nanoghost with a diameter and shell size of 125 nm and 8.3 nm was obtained based on the TEM measurement. The fabricated nanoghost was not only hemocompatible but also was biocompatible, showing no significant induction of apoptosis. According to RT-PCR assay, the expression levels of inflammatory genes including NLRP3, IL-1β, IL-18 caspase1, 8 and 9 were decreased. In accordance with in vitro anti-inflammation properties, total foam cells, total surface area in tunica intima and population of CD14+ cells were decreased in the rabbit model of atherosclerosis upon nanoghost treatment, compared to positive control. Furthermore, macrophages in aorta sections exhibited M1 to M2 polarization. In general, the development of Glyburide-loaded nanoghost can be considered as a potential therapeutic for controlling the progression and inflammation of atherosclerotic plaque

Synthetic and biological identities of polymeric nanoparticles influencing the cellular delivery:An immunological link

Enhanced understanding of bio-nano interaction requires recognition of hidden factors such as protein corona, a layer of adsorbed protein around nano-systems. This study compares the biological identity and fingerprint profile of adsorbed proteins on PLGA-based nanoparticles through nano-liquid chromatography-tandem mass spectrometry. The total proteins identified in the corona of nanoparticles (NPs) with different in size, charge and compositions were classified based on molecular mass, isoelectric point and protein function. A higher abundance of complement proteins was observed in modified NPs with an increased size, while NPs with a positive surface charge exhibited the minimum adsorption for immunoglobulin proteins. A correlation of dysopsonin/opsonin ratio was found with cellular uptake of NPs exposed to two positive and negative Fc receptor cell lines. Although the higher abundance of dysopsonins such as apolipoproteins may cover the active sites of opsonins causing a lower uptake, the correlation of adsorbed dysopsonin/opsonin proteins on the NPs surface has an opposite trend with the intensity of cell uptake. Despite the reduced uptake of corona-coated NPs in comparison with pristine NPs, the dysopsonin/opsonin ratio controlled by the physicochemistry properties of NPs could potentially be used to tune up the cellular delivery of polymeric NPs. (C) 2019 Elsevier Inc. All rights reserved