Electrospinning of amoxicillin-loaded biodegradable polycaprolactone/hydroxyapatite nanofibers

G. FURTOS; G. RIVERO; G.A. ABRAHAM

Novi Sad

Workshop; Meeting and Workshop on "Composite, nanofabrication, food and pharma related application and packaging, controlled release"; 2015

University of Novi Sad y COST Action MP1206

The purpose of this work was the preparation and properties characterization of new drug-loaded electrospun nanocomposite scaffolds. Blends composed of polycaprolactone (PCL) and nanohydroxyapatite (nHAp) loaded with amoxicillin (AMX) have been prepared as material designed for biomedical applications. The investigated systems contained poly(e-caprolactone) (average Mw ~80,000, Aldrich), synthesized nanohydroxyapatite and amoxicillin. Different types of electrospun nanocomposite and antibiotic-loaded nanocomposite scaffolds were obtained by varying the components  AMOX (0, 1, 1.5%), nHAp (0, 10, 15, 20%), to produce a series of PCL/AMOX, PCL/nHAp and PCL/AMOX/nHAp matrices. PCL concentration was kept constant at 15 % wt/v. Solutions were obtained by disolving or dispersing the components in chlorofom:methanol (3:1). Electrospinning was carried out at room temperature by applying a voltage in the range of 15-28 kV, a needle-tip-collector distance of 12 cm, and a flow rate 6 ml.h-1. These setting parameter were established after several experiments in which applied voltage and needle tip-to-collector distance were varied to allow a stable cone-jet regime during all the electrospinning process. Scaffolds were removed from the collector, dried under vacuum at room temperature to fully eliminate the residual solvent, and finally stored in a desiccator. The structural, morphological, surface and thermal properties were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM, EDAX), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and contact angle measurements. SEM micrographs showed that HA nanoparticles were well dispersed in random electrospun nanocomposite scaffolds. SEM images displayed exhibited mats with bead-free morphology. Mean fiber diameter of samples with the same AMOX content increased with the increase of nHAp content. For example, A1b0 (PCL/AMOX1/nHAp0) exhibited a mean fiber diameter of 1.3 ± 0.35 mm while A1b20 displayed a mean diameter of 2.42 ± 1.34 mm. Electrospun PCL exhibited a decrease in crystallinity and melting temperature with respect to PCL pellet (raw material). This is a typical behavior associated to the electrospinning technique, in which a short evaporation time lead to the formation of small crystallites and low crystallinity degree values. For samples loaded with AMOX and nHAp no significant variation in the crystallinity degree and melting temperature was observed. Water contact-angle measurements results showed no significant variation with the nHAp content, suggesting that nHAp is completely incorporated inside the fiber. The current research include bioactivity experiments via soaking in simulated body fluid (SBF) solution at 37°C, AMX release profiles at 37°C (as determined by ultraviolet-visible spectroscopy), release kinetics modelling, as well as antimicrobial testing are ongoing. These results and its complete analysis will be shortly available.