Study on the Release and Bioevaluations of Green Silver Nanoparticles Entrapped Inside Polymer-based Nanovesicles

Abstract

The drug carriers represent a very important and modern pathway used to increase the therapeutic efficacy of the natural active substances. Nano-sized assemblies of noble metals and herbal extracts represent very simple, cheap, biologically and ecologically friendly synthesis. The main aims of this study were to obtain polyurethane nanovesicles containing silver nanoparticles and to evaluate their release rate. The vesicles� sizes, homogeneity and surface charge were studied using a Cordouan Technol. Zetasizer, while the thermal behaviour was assessed by DSC. UV-Vis measurements were done to evaluate the release rate. Toxicological effects were studied by non-invasive techniques on human skin. The results suggest the obtaining of homogenous polyurethane nanovesicles between 80 and 95 nm, with positive surface charge, very good thermal stability and a prolonged release. The non-irritation potential recommends these vesicles as a safe carrier for different herbal extracts.

Synthesis and Preliminary Characterization of Polyurethane Matrices Used as a Drug Carrier for Bromelain

“…An UVi Line 9400 SI Analytics Spectrophotometer (Mainz, Germany) was used to investigate the encapsulation efficacy (EE) of bromelain inside the polyurethane matrices and the cumulative drug release (CDR) according to the following procedures that were already published by our team: EE can be estimated by reporting the amount of the free bromelain to the total amount that was used in the synthesis: EE = [(Wi-Wf)/Wi]×100 %, where Wf is the total amount of bromelain from the water-acetone mixture used in the washing / centrifugation process and Wi is the total quantity of bromelain added initially [20], while CDR was calculated after the exposure of sample PUM_1 inside a degradative media consisting in a mixture of NaHCO3, Na2HPO4, NaCl, KH2PO4, K2HPO4, KCl and MgCl2 at similar concentrations and pH with the human plasma. CDR = volume of sample withdrawn (mL) / bath volume × P(t-1) + Pt, where Pt is percentage release at time "t" and P(t-1) is percentage release previous to "t" [21]; all spectrometry analyses were based on the difference between the maximum absorption (280 nm for bromelain and around 358 nm for polyurethane matrices), a calibration curve (bromelain absorption vs. its concentration) and the Beer-Lambert law.…”

Stability Profile and Clinical Evaluation of an Innovative Hydrogel Containing Polymeric Micelles as Drug Delivery Systems with Oregano Essential Oil against Fibroepithelial Polyps

“…As a result of the erythema evaluation, OEO-PbH can be considered to be safe for human administration. Products with a strong irritative effect will be conducted to a significantly increased erythema index (the instrument can measure erythema values up to 1000 units) [ 77 ]. According to Firooz et al, the average normal values for erythema index, TEWL, and hydration are around 303.63 ± 100.73, 9.52 ± 7.36, and 49.06 ± 16.09 A.Us.…”

Gamma Radiation Synthesis of Silver Nanoparticles/Chitosan composites with antimicrobial properties

“…Ag Np can be synthesized by different ways such as: chemical [7,8], physical [9] and biological [8,10,11]. Generally, the chemical, conventional, methods are performed in aqueous solutions of Silver salt precursor (i.e.…”