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Various biocompatible polymers have been developed using electrospun nanofibers for local drug delivery matrices, but many of them are non-FDA-approved polymers or chemicals. Material safety should be considered in biomedical devices, but the effectiveness of electrospun nanofibers is limited with only the approved chemicals. Therefore, we considered the material in FDA-approved polymers and solvents and developed nanofibers using the general additives in the pharmaceutical industry, such as hypromellose, poly(vinyl alcohol) (PVA), and Gellan. The nanofiber, mainly composed of hypromellose and PVA, was applied to a local peptide drug delivery system. Electrostatically complexed Gellan and peptide were loaded in the nanofiber by co-electrospinning. The morphology of the nanofibers with different PVA blending ratios was visualized by scanning electron microscope. The nanofiber composed of only hydrophilic polymers quickly wetted in water and became a transparent gel-like lump. A drug release test of peptide-loaded nanofiber was performed resulted in 37% of initial burst release suppression with the gellan and peptide loaded nanofiber compared with solely peptide loaded hypromellose nanofiber. In addition, higher PVA blending to hypromellose was slightly effective for sustained release of peptide compared with pure peptide-loaded hypromellose nanofiber. Therefore, we suggest the potential application of hypromellose/PVA nanofiber-loaded Gellan/peptide complex to a mucosal layer drug delivery patch.

Cancer cells overexpressing folate receptors have been targeted using a folate decorated carriers for anti-cancer drugs in aims to overcome the tissue non-specificity of anti-cancer agents. We here prepared magnetic nanoparticles and surface-decorated them with different amounts of folate to optimize the number of the immobilized folate on the carriers for superior targeting effects. Magnetic nanoparticles were prepared by oxidizing ferric or ferrous chloride solution to iron oxide in the presence of poly(vinyl alcohol). The magnetic nanoparticles were functionalized with primary amines for subsequent reactions with the different feed ratios of the activated folate. The magnetization degree of the folate magnetic magnetization were slightly decreased when the folate on the particles were increased. Intracellular uptakes of the nanoparticles were shown to be increased and become saturated dependent on the amounts of the surface-immobilized folate. The folate-decorated magnetic nanoparticles showed negligible cytotoxicity against KB cells from 5 μg to 35 μg of the nanoparticle weights.

A simple and efficient method to fabricate size-controlled nanoporous-nanofibrous meshes has been demonstrated by introducing and removing novel size-controllable porogens, reverse micelles, on electrospun polymeric nanofibers. Poly(D,L-lactide) and reverse micelles composed of amphiphilic diblock copolymer, poly(ethylene glycol) methyl ether-block-poly(e-caprolactone), were first dissolved in an acetone/chloroform (3:1, v/v) mixture and then electrospun into nanofibers, followed by 70% EtOH post-treatment. During the post-treatment, the reverse micelles were dissolved in 70% EtOH at room temperature thus separated from the poly(D,L-lactide) nanofibers backbone, resulting in a nanoporous nanofibrous structure. The pores on the nanofibers are size-controllable because the sizes of the reverse micelles can be adjusted by varying the water content inside them. The sizes of reverse micelles, which ranged from 100 nm to 700 nm, are investigated by dynamic light scattering. The pores of various sizes on the poly(D,L-lactide) nanofibers have areas ranging from 20 μm2 to 80 μm2 were observed by field-emission scanning electron microscopy.

Nanofibrous matrix was fabricated for the purpose of obtaining bi-phasic protein releases from a single protein delivery system. A block copolymer composed of poly(ethylene glycol) and poly(epsilon-caprolactone) was co-electrospun with protein solutions through a dual nozzle electrospinning system. Surface-exposed amine groups of the protein-encapsulating nanofiber at an aqueous phase were chemically conjugated to the carboxyl groups of another protein for surface-immobilization. The surface-immobilized proteins and the core-encapsulated proteins in the nanofibers were characterized by scanning electron microscopy and confocal microscopy. Encapsulation efficiency of protein in the core of the nanofiber was increased when poly(vinyl alcohol) was mixed in the protein solution. Flow rate ratios of protein solutions to polymeric solutions significantly affected encapsulation efficiency of proteins in the nanofiber, where high flow rate ratios increased encapsulation efficiencies of proteins in the nanofiber. Release profiles of the immobilized proteins and the encapsulated proteins from the nanofiber were examined for 4 days. The encapsulated proteins showed initial burst profiles while the surface-immobilized proteins showed no or minimal release of proteins for the release period. Thus, the nano-inspired fibrous matrix can be potentially employed to fabricate a drug delivery device with a bi-phasic release profile of proteins.