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A novel approach to fabricate silk nanofibers containing hydroxyapatite nanoparticles using a three-way stopcock connector.

Sheikh FA, Ju HW, Moon BM, Park HJ, Kim JH, Lee OJ, Park CH - Nanoscale Res Lett (2013)

Bottom Line: In this work, we had successfully used a three-way stopcock connector to mix the two different solutions, and very shortly, this solution is ejected out to form nanofibers due to electric fields.Different blend ratios consisting HAp NPs had been electrospun into nanofibers.These characterization techniques revealed that HAp NPs can be easily introduced in silk nanofibers using a stopcock connector, and this method favorably preserves the intact nature of silk fibroin and HAp NPs.

View Article: PubMed Central - HTML - PubMed

Affiliation: Nano-Bio Regenerative Medical Institute, College of Medicine, Hallym University, Chuncheon 200-702, South Korea ; Department of Chemistry, University of Texas-Pan American, Edinburg, Texas 78539, USA.

ABSTRACT
Electrospinning technique is commonly used to produce micro- and/or nanofibers, which utilizes electrical forces to produce polymeric fibers with diameters ranging from several micrometers down to few nanometers. Desirably, electrospun materials provide highly porous structure and appropriate pore size for initial cell attachment and proliferation and thereby enable the exchange of nutrients. Composite nanofibers consisting of silk and hydroxyapatite nanoparticles (HAp) (NPs) had been considered as an excellent choice due to their efficient biocompatibility and bone-mimicking properties. To prepare these nanofiber composites, it requires the use of acidic solutions which have serious consequences on the nature of both silk and HAp NPs. It is ideal to create these nanofibers using aqueous solutions in which the physicochemical nature of both materials can be retained. However, to create those nanofibers is often difficult to obtain because of the fact that aqueous solutions of silk and HAp NPs can precipitate before they can be ejected into fibers during the electrospinning process. In this work, we had successfully used a three-way stopcock connector to mix the two different solutions, and very shortly, this solution is ejected out to form nanofibers due to electric fields. Different blend ratios consisting HAp NPs had been electrospun into nanofibers. The physicochemical aspects of fabricated nanofiber had been characterized by different state of techniques like that of FE-SEM, EDS, TEM, TEM-EDS, TGA, FT-IR, and XRD. These characterization techniques revealed that HAp NPs can be easily introduced in silk nanofibers using a stopcock connector, and this method favorably preserves the intact nature of silk fibroin and HAp NPs. Moreover, nanofibers obtained by this strategy were tested for cell toxicity and cell attachment studies using NIH 3 T3 fibroblasts which indicated non-toxic behavior and good attachment of cells upon incubation in the presence of nanofibers.

No MeSH data available.


Related in: MedlinePlus

The FT-IR spectra of the nanofibers obtained after electrospinning. Pristine nanofibers (spectrum A), silk fibroin nanofibers modified with 10% HAp NPs (spectrum B), 30% HAp NPs (spectrum C), and 50% HAp NPs (spectrum D).
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Figure 12: The FT-IR spectra of the nanofibers obtained after electrospinning. Pristine nanofibers (spectrum A), silk fibroin nanofibers modified with 10% HAp NPs (spectrum B), 30% HAp NPs (spectrum C), and 50% HAp NPs (spectrum D).

Mentions: FT-IR can be used as an efficient tool to investigate the structural confirmations because of the knowledge of the vibration origins of the amide bonds, the sensitivity of some of these band positions to conformation, and the possibility of predicting band positions for a given helical or extended conformation [30]. The changes occurred on the band positions for pristine, and the one modified with HAp NPs is expressed in Figure 12. The vibrations occurred in pristine nanofiber due to amide Ι, amide II, and amide III bands can be seen at 1,626 cm−1, 1,516 cm−1, and 1,232 cm−1 which confirm the nature of the silk fibroin in the nanofibers. Moreover, nanofibers modified with HAp also showed the presence of these amide bands; however, there was a downshift of 1 to 2 units for amide Ι and amide II bands. The reason is to show that this shift can be attributed to conformational changes occurred in the silk fibroin from random coil structure to β-sheet confirmation due to the incorporation of HAp NPs [31,32]. The vibration modes caused due to the presence of Ca and P in nanofibers modified with HAp NPs can also be seen at different band positions. For instance, a small shoulder peaks at 1,472 cm−1, which indicates the existence of a Ca-O phase. The peaks appearing at 1,059 cm−1 and 1,097 cm−1 can be attributed due to the asymmetric stretching mode vibration in PO4−3, and a medium intensity band at about 962 cm−1 results from P-O asymmetric stretching of the stretching vibrations in PO4−3[33]. Also, a sharp peak at 836 cm−1 is assigned to the O-H bending deformation mode due to the presence of HAp NPs in the nanofibers. The intensity of these peaks increases as the amount of original HAp used to make colloidal solution for electrospinning increases.


A novel approach to fabricate silk nanofibers containing hydroxyapatite nanoparticles using a three-way stopcock connector.

Sheikh FA, Ju HW, Moon BM, Park HJ, Kim JH, Lee OJ, Park CH - Nanoscale Res Lett (2013)

The FT-IR spectra of the nanofibers obtained after electrospinning. Pristine nanofibers (spectrum A), silk fibroin nanofibers modified with 10% HAp NPs (spectrum B), 30% HAp NPs (spectrum C), and 50% HAp NPs (spectrum D).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3750300&req=5

Figure 12: The FT-IR spectra of the nanofibers obtained after electrospinning. Pristine nanofibers (spectrum A), silk fibroin nanofibers modified with 10% HAp NPs (spectrum B), 30% HAp NPs (spectrum C), and 50% HAp NPs (spectrum D).
Mentions: FT-IR can be used as an efficient tool to investigate the structural confirmations because of the knowledge of the vibration origins of the amide bonds, the sensitivity of some of these band positions to conformation, and the possibility of predicting band positions for a given helical or extended conformation [30]. The changes occurred on the band positions for pristine, and the one modified with HAp NPs is expressed in Figure 12. The vibrations occurred in pristine nanofiber due to amide Ι, amide II, and amide III bands can be seen at 1,626 cm−1, 1,516 cm−1, and 1,232 cm−1 which confirm the nature of the silk fibroin in the nanofibers. Moreover, nanofibers modified with HAp also showed the presence of these amide bands; however, there was a downshift of 1 to 2 units for amide Ι and amide II bands. The reason is to show that this shift can be attributed to conformational changes occurred in the silk fibroin from random coil structure to β-sheet confirmation due to the incorporation of HAp NPs [31,32]. The vibration modes caused due to the presence of Ca and P in nanofibers modified with HAp NPs can also be seen at different band positions. For instance, a small shoulder peaks at 1,472 cm−1, which indicates the existence of a Ca-O phase. The peaks appearing at 1,059 cm−1 and 1,097 cm−1 can be attributed due to the asymmetric stretching mode vibration in PO4−3, and a medium intensity band at about 962 cm−1 results from P-O asymmetric stretching of the stretching vibrations in PO4−3[33]. Also, a sharp peak at 836 cm−1 is assigned to the O-H bending deformation mode due to the presence of HAp NPs in the nanofibers. The intensity of these peaks increases as the amount of original HAp used to make colloidal solution for electrospinning increases.

Bottom Line: In this work, we had successfully used a three-way stopcock connector to mix the two different solutions, and very shortly, this solution is ejected out to form nanofibers due to electric fields.Different blend ratios consisting HAp NPs had been electrospun into nanofibers.These characterization techniques revealed that HAp NPs can be easily introduced in silk nanofibers using a stopcock connector, and this method favorably preserves the intact nature of silk fibroin and HAp NPs.

View Article: PubMed Central - HTML - PubMed

Affiliation: Nano-Bio Regenerative Medical Institute, College of Medicine, Hallym University, Chuncheon 200-702, South Korea ; Department of Chemistry, University of Texas-Pan American, Edinburg, Texas 78539, USA.

ABSTRACT
Electrospinning technique is commonly used to produce micro- and/or nanofibers, which utilizes electrical forces to produce polymeric fibers with diameters ranging from several micrometers down to few nanometers. Desirably, electrospun materials provide highly porous structure and appropriate pore size for initial cell attachment and proliferation and thereby enable the exchange of nutrients. Composite nanofibers consisting of silk and hydroxyapatite nanoparticles (HAp) (NPs) had been considered as an excellent choice due to their efficient biocompatibility and bone-mimicking properties. To prepare these nanofiber composites, it requires the use of acidic solutions which have serious consequences on the nature of both silk and HAp NPs. It is ideal to create these nanofibers using aqueous solutions in which the physicochemical nature of both materials can be retained. However, to create those nanofibers is often difficult to obtain because of the fact that aqueous solutions of silk and HAp NPs can precipitate before they can be ejected into fibers during the electrospinning process. In this work, we had successfully used a three-way stopcock connector to mix the two different solutions, and very shortly, this solution is ejected out to form nanofibers due to electric fields. Different blend ratios consisting HAp NPs had been electrospun into nanofibers. The physicochemical aspects of fabricated nanofiber had been characterized by different state of techniques like that of FE-SEM, EDS, TEM, TEM-EDS, TGA, FT-IR, and XRD. These characterization techniques revealed that HAp NPs can be easily introduced in silk nanofibers using a stopcock connector, and this method favorably preserves the intact nature of silk fibroin and HAp NPs. Moreover, nanofibers obtained by this strategy were tested for cell toxicity and cell attachment studies using NIH 3 T3 fibroblasts which indicated non-toxic behavior and good attachment of cells upon incubation in the presence of nanofibers.

No MeSH data available.


Related in: MedlinePlus