Paclitaxel‐loaded composite fibers: Microstructure and emulsion stability

Abstract

New core/shell fiber structures loaded with paclitaxel were developed and studied. These composite fibers are ideal for forming thin, delicate, biomedically important structures for various applications. Possible applications include fiber-based endovascular stents that mechanically support blood vessels while delivering drugs for preventing restenosis directly to the blood vessel wall, or drug delivery systems for cancer treatment. The core/shell fiber structures were formed by "coating" nylon fibers with porous paclitaxel-containing poly(DL-lactic-co-glycolic acid) structures. Shell preparation ("coating") was performed by freeze-drying water in oil emulsions. The present study focused on the effects of the emulsion's formulation (composition) and processing conditions on the porous shell structure, which actually reflects the emulsion's stability and also the drug release profile from the fibers. In general, extremely porous "shell" structures were obtained with good adhesion to the core fiber. An increase in the emulsion's drug content and copolymer composition demonstrated a significant effect on pore size and distribution, because of enhanced emulsion instability, whereas the homogenization rate and duration had only a slight effect on the pores' microstructure. The thermodynamic parameters in the studied system are thus more important than the kinetic parameters in determining the emulsion's stability and the shell's porous structure.

Electrohydrodynamics: A facile technique to fabricate drug delivery systems

“…Figure 1a and b demonstrate the presence of core-shell feature in paclitaxel-loaded PLGA fibers designed to function as drug-eluting sutures. The electrospun fibers are capable of delivering paclitaxel over a period of 3 months but suffer from reduced mechanical properties [43, 51, 52]. Figure 1c–e illustrate the use of optical (c) and scanning electron microscopy (d–e) to visualize hollow core features of the microtubes produced from co-axial electrospinning using poly(caprolactone) as the shell and poly (ethylene oxide) as the core [40].…”

“…A notable variable introduced in their work involves forming PCL (shell)/PMMA (core) fibers, and modulating the concentration of PMMA to significantly influence the rate of rhodamine being released [61]. Kraitzer et al correlate the degradability of different blends of poly(lactic-glycolic acid) (75/25 vs. 50/50 PLGA) and the resulting influence on the release kinetics of paclitaxel [51, 52]. Increasing the degradation rate by increasing the ratio of fast-degrading PGA resulted in a faster release of paclitaxel (80% in 40 weeks vs. 30% with 75/25 PLGA).…”

Comparison of Nanocomposite Film and Electrospun Nanocomposite Fibers Based on Poly (2-Hydroxy Ethyl Methacrylate) and Microcrystalline Cellulose as Anticancer Implants

“…Figure 1c shows the presence of defibrilled cellulose [42] on the p(HEMA) surface. The incorporation of hydrophobic paclitaxel into the hydrophilic p(HEMA) and cellulose solution decreases the surface tension of the polymer solution [43] and this solution, when cast as a film, eventually leads to aggregation of phase-separated paclitaxel, cellulose and p(HEMA) as microspheres on the surface, as observed in the SEM images of Figure 1d. These results show that the dispersion of paclitaxel was uniform in the case of electrospun nanocomposite fibers compared to the nanocomposite film.…”

Drug delivery systems using biotextiles

“…Moreover, there was no need for any surgical operation after the drugs were exhausted. 17 Kraitzer et al 14 prepared a new core/shell fi ber structure loaded with paclitaxel. This was achieved by combining nylon fi bers with the technique of freeze drying an inverted emulsion during the after-treatment drug-loading process.…”