Release and antimicrobial activity of levofloxacin from composite mats of poly(ɛ-caprolactone) and mesoporous silica nanoparticles fabricated by core–shell electrospinning

Abstract

Nanofibrous materials have often been reported as carriers for clinical drugs but face the limitation of releasing the drugs in a burst fashion during use. The aim of this study is to produce composite nanofibrous mats with sustained release, using the broad spectrum antibiotic levofloxacin (LVF) as a model. Sustained release was achieved through two approaches, i.e. by firstly loading LVF into mesoporous silica nanoparticles (MSN) and then incorporating the MSN in the core regions of poly(ecaprolactone) (PCL) nanofibres via core-shell electrospinning. Uniform PCL/LVF nanofibrous mats were also produced as controls. Loading of LVF into the MSN nanopores was confirmed by FTIR, BJH and BET measurements (100 mg LVF/g MSN). After electrospinning, electron microscopy revealed that the MSN were indeed confined in the core regions of the nanofibres. Drug release profiles showed that burst release was decreased from 59 % in the uniform PCL/LVF electrospun mats to 39 % in the core-shell PCL/LVF-MSN mats after 1 day in phosphate buffer at 37°C, and gradual release in the latter was observed over the next 13 days. Antimicrobial assays showed that the composite electrospun mats were highly effective in killing Escherichia coli even after the mats had been incubated in a phosphate buffer for 14 days while the uniform PCL/LVF mats lost the ability after only 7 days. The results indicate that adsorption of the drug onto MSN and confining them in the core of nanofibres are effective ways of minimizing burst release and achieving sustained release of the drug.

Electrospinning: A promising technique for drug delivery systems

“…Silica nanoparticles have been very versatile to load different kinds of drugs and then embedded in electrospun polymers. These systems include PCL/silica nps with differents loaded drugs such as allantoin [57], levofloxacin [58], camptothecin [59], gentamicin [60]; also drug-loaded silica nanoparticles have been incorporated in Poly(L-Lactic acid) for doxorubicin release [61], poly(vinyl alcohol) for methylene blue release [62]. To incorporate drug-loaded silica nanoparticles into the electrospun matrix polymer is one of the main methods, but there are other systems of drug-loaded particles/polymer which are widely used in the electrospinning process, like bovine serum albumin (BSA) particles that were loaded with dexamethasone (DEX) and bone morphogenetic protein-2 (BMP-2) and then embedded in poly(caprolactone)-co-poly(ethylene glycol) copolymer, the dual-drug-loaded system was very effective to induce differentiation towards osteoblasts thanks to its synergistic effect of BMP-2 and DEX [63].…”

Electrospun Poly(vinyl Alcohol) Nanofibers Doped With Mesoporous Silica Nanoparticles for Controlled Release of Hydrophilic Model Drug

“…Furthermore, the average nanofiber diameter increased up to 529 nm in PVA-loaded MSNs electrospun mats as plotted through diameter distributions in Figure 3(c). This occurrence is due to the aggregation of MSNs in the polymer solution during electrospinning, rise in solution viscosity or incomplete dispersion during initial dispersion process into the polymer solution [6]. Figure 4(a) and (c), respectively.…”

“…In order to overcome this problem, the encapsulating of the drugs in nanoparticles and incorporation of nanoparticles into random electrospun nanofiber has been employed. For instance, Jalvandi et al [6] reported approximately 70% of levofloxacin (LVF) in the nanoparticles was release in burst fashion throughout the first 20 min compared to 45% of LVF released from core shell nanofiber in the first day. Song et al [7] were studied designed a co-delivery system based on poly(lactic-co-glycolic acid)(PLGA) and nanoparticles for drug delivery applications.…”

Antimicrobial Polymers in the Nano-World

“…Jalvandi et al [ 79 ] loaded LV into mesoporous silica NPs (MSN), which were subsequently incorporated in the core region of PCL nanofibers via core–shell electrospinning. The antibiotic release from these fibres was more gradual than when released from PCL-LV and PCL-LV core-shell nanofibrous mats.…”