Facile preparation of titanium dioxide micro/nanofibers and tubular structures by air jet spinning

Air jet spinning (AJS) method has been successfully used for manufacturing of micro/nanofibers. AJS method offers a fiber production rate that is several times higher than those produced by electrospinning. This paper discusses the preparation of TiO2 in two different morphological structures using a one-step AJS based on sol-gel blends of alkoxide precursor (titanium isopropoxide), Ti(iso) and poly(vinyl acetate) (PVAc) solutions. Our results confirmed that TiO2 fibers and tubular structures can be prepared by controlling the proportions of Ti(iso) precursor. Spinning Ti(iso)/PVAc solutions with low precursor concentrations (25%) yielded fibers with smooth surfaces. Increasing the precursor concentration more than 25% resulted in production of very rough fibers of highly tubular structure. Overall, the AJS technique proved to be a valuable method for future research related to polymer and ceramic fiber processing and fabrication

A novel simple one-step air jet spinning approach for deposition of poly(vinyl acetate)/hydroxyapatite composite nanofibers on Ti implants

A biocompatible coating consists of a poly(vinyl acetate)/hydroxyapatite (PVAc/HA) composite nanofiber mat was applied to NaOH-treated titanium metal by means of a novel, facile and efficient air jet spinning (AJS) approach. Results showed that HA nanoparticles (NPs) strongly embedded onto the AJS single fiber surface resulting in a strong chemical interfacial bonding between the two phases due to the difference in kinetic energies. It was proven that AJS membrane coatings can provide significant improvement in the corrosion resistance of titanium substrate. Interestingly, the biocompatibility using MC3T3-E1 osteoblast to the PVAc/HA fiber composite layer coated on Ti was significantly higher than pure titanium-substrates

Air jet spray of nylon 6 membrane structures for bone tissue engineering

A novel porous nylon 6 (N6) scaffold with high and low porosity was designed using a facile, one-step approach. The scaffold samples were prepared using air jet spray (AJS) to obtain high production rates as an alternative low cost, effective technique with precise thickness control. The present results show that AJS adequately produced interconnected porous networks ranging from micron to submicron scales that were observed using a scanning electron microscope. The effect of AJS on the secondary structure of N6 was examined to identify and quantify conformational changes that occurred due to processing. The mechanical properties of the fabricated samples were tested. The results of tensile tests indicated higher tensile strength of AJS scaffold than that of electrospun scaffold. © 2014 Elsevier B.V. All rights reserved

Preparation and characterization of vertically arrayed hydroxyapatite nanoplates on electrospun nanofibers for bone tissue engineering

The aim of this study is to develop a facile and an efficient approach for providing the electrospun nanofibers scaffold with a vertically well-aligned and homogeneous distribution of hydroxyapatite (HA) nanoplates that coat the scaffold while maintaining its fibrous and porous structure. Crystal growth of HA nanoplates from a colloidal solution onto the surface of nylon (N6) nanofibers was carried out via a hydrothermal approach. The factors affecting the scaffold's morphology, macrostructure and the interfacial bonding between the constituents as well as the influence of crystal size were characterized and well elucidated. The results revealed that the deposition of dense and thick uniform nanoplates was perpendicular and nucleated in a parallel configuration onto the longitudinal axes of the individual nanofibers during the treatment process. The sizes of the nanoplates, which are strongly dependent on the reaction time, were 30 and 95. nm in length, with thicknesses of 17-19. nm, after 2 and 3. h respectively. The nanoplates improve the mechanical properties of the HA/N6 biocomposite scaffolds. The surface properties of the fabricated scaffolds appeared to have a greater effect on the early stages of osteoblast behavior (cell attachment and proliferation). The cells attached, grew and proliferated faster on culture-coated scaffolds in comparison with the pristine ones. Our results indicate that the treated scaffolds fulfill the basic requirements of bone tissue engineering scaffolds, and have the potential to be applied in orthopedic and reconstructive surgeries. © 2014 Elsevier B.V

Characterization of the surface biocompatibility of an electrospun nylon 6/CaP nanofiber scaffold using osteoblasts

The purpose of this research is to improve the biocompatibility of bone tissue engineering scaffolds using a one-step electrospinning process. Calcium phosphate (CaP) was coated on the surface of nylon 6 (N6) nanofibers to form an ultrathin layer, thereby increasing surface roughness and wettability of the N6 nanofiber membrane in order to further improve implant tissue integration. The morphology, composition, chemical interaction bonding and mechanical properties of CaP-coated N6 nanofibers were characterized. The wettability of the scaffold was measured in terms of the water contact angle, and the results indicated that N6 fibers coated with an ultrathin layer of CaP exhibited an excellent surface wettability (water contact angle = 0°). Mechanical testing revealed higher properties of coated CaP layers compared to a plain N6 mat. The biological response induced by the surface modifications of N6 fibers was evaluated by in vitro cell culture with MC3T3-E1 osteoblasts cells. It was found that CaP-coated N6 nanofibrous matrices definitely favored cell proliferation, with the efficiency dependent upon the coating technique. A combination of a nanoscale fibrous structure and a CaP coating could mimic the structure, composition and function of bone tissues. © 2012 Elsevier B.V