biomimetic nanocomposites with selective molecular ... - CiteSeerX
BIOMIMETIC NANOCOMPOSITES WITH SELECTIVE MOLECULAR ADSORPTION USING ELECTROSPUN NANOFIBER AFFINITY MEMBRANES Keiichi Yoshimatsu 1, Lei Ye 1*, Johanna Lindberg 2, Ioannis S. Chronakis 2* 1
Pure and Applied Biochemistry, Chemical Center, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden 2 IFP Research, Swedish Institute for Fiber and Polymer Research, P.O. Box 104, SE-431 22 Mölndal, Sweden
KEYWORDS: molecular imprinting, electrospinning, nanofiber, nanoparticle, affinity membrane. Electrospinning of nanofibers Electrospinning is a fibre spinning technology for the production of ultrafine fibres on the nano-scale made of various materials. This technique involves the use of a high voltage electrostatic field to charge the surface of a polymer solution droplet and thus to induce the ejection of a liquid jet through a spinneret. As the jet travels through the air, the solvent evaporates and due to bending instability, the jet is subsequently stretched by many times to form continuous, ultra thin fibres on the target. The electrospinning process parameters (applied potential, electric field lines, spinning distance, flow rate), fluid parameters (conductivity, viscosity, surface tension, dielectric constant) and spinning materials (pure an mixed bio/polymer solutions, composite mixtures for encapsulation, etc) can be adjusted to tune and optimise micro-& nanofibre morphologies and characteristics. When used in products, the unique properties of nanofibers are utilised like extraordinary high surface area per unit mass, very high porosity, tuneable pore size, tuneable surface properties, layer thinness, high permeability, low basis weight, cost effectiveness, etc.
Molecularly imprinted nanofibers Pre-made molecularly imprinted nanoparticles were encapsulated into composite nanofiber membranes using the electrospinning processing method (Fig 1).
Figure 1: SEM image of electrospun nanofiber composite membrane containing molecular imprinted nanoparticles. The scale bar is 1µm.
The composite nanofibers form non-woven mats that can be used as affinity membrane to greatly simplify solid phase extraction of drug residues in analytical samples. Upward 100% of propranolol-imprinted nanoparticles can be easily encapsulated into poly(ethylene terephthalate) nanofibers, ensuring the composite materials to have a high specific binding capacity. As confirmed by radioligand binding analysis, the specific binding sites in the composite materials remain easily accessible and are chiral-selective (Fig. 2). Using the new composite nanofiber mats as solid phase extraction materials, trace amount of propranolol (1 ng mL-1) in solution can be easily detected after a simple sample preparation. Without the solid phase extraction, the existence of propranolol residues in solution cannot be confirmed with even tandem HPLC-MS/MS analysis. In conclusion, the electrospinning of composite nanofibers containing molecularly imprinted nanoparticles produced a new type of molecular recognition biomimetic matrix, which has potential applications in affinity separation, sensing and diagnostics.
Propranolol uptake (%)
80
imprinted non-imprinted 60
40
20
0 0
10
20
30
40
50
Nanoparticle content (%) Figure 2: Uptake of propranolol with imprinted and non-imprinted composite membranes in a buffer solution
REFERENCES 1. Chronakis, I.S., Milosevic, B., Frenot, A., Ye, L., ‘Generation of molecular recognition sites in electrospun polymer nanofibers via molecular imprinting’. Macromolecules, 39, 357-361, 2006. 2. Chronakis, I. S., Jakob, A., Hagström, B., Ye ,L., ‘Encapsulation and Selective Recognition of Molecularly Imprinted Theophylline and 17beta-Estradiol Nanoparticles within Electrospun Polymer Nanofibers.’ Langmuir, 22, 8960-8965, 2006.
Pure and Applied Biochemistry, Chemical Center, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden 2 IFP Research, Swedish Institute for Fiber and Polymer Research, P.O. Box 104, SE-431 22 Mölndal, Sweden
KEYWORDS: molecular imprinting, electrospinning, nanofiber, nanoparticle, affinity membrane. Electrospinning of nanofibers Electrospinning is a fibre spinning technology for the production of ultrafine fibres on the nano-scale made of various materials. This technique involves the use of a high voltage electrostatic field to charge the surface of a polymer solution droplet and thus to induce the ejection of a liquid jet through a spinneret. As the jet travels through the air, the solvent evaporates and due to bending instability, the jet is subsequently stretched by many times to form continuous, ultra thin fibres on the target. The electrospinning process parameters (applied potential, electric field lines, spinning distance, flow rate), fluid parameters (conductivity, viscosity, surface tension, dielectric constant) and spinning materials (pure an mixed bio/polymer solutions, composite mixtures for encapsulation, etc) can be adjusted to tune and optimise micro-& nanofibre morphologies and characteristics. When used in products, the unique properties of nanofibers are utilised like extraordinary high surface area per unit mass, very high porosity, tuneable pore size, tuneable surface properties, layer thinness, high permeability, low basis weight, cost effectiveness, etc.
Molecularly imprinted nanofibers Pre-made molecularly imprinted nanoparticles were encapsulated into composite nanofiber membranes using the electrospinning processing method (Fig 1).
Figure 1: SEM image of electrospun nanofiber composite membrane containing molecular imprinted nanoparticles. The scale bar is 1µm.
The composite nanofibers form non-woven mats that can be used as affinity membrane to greatly simplify solid phase extraction of drug residues in analytical samples. Upward 100% of propranolol-imprinted nanoparticles can be easily encapsulated into poly(ethylene terephthalate) nanofibers, ensuring the composite materials to have a high specific binding capacity. As confirmed by radioligand binding analysis, the specific binding sites in the composite materials remain easily accessible and are chiral-selective (Fig. 2). Using the new composite nanofiber mats as solid phase extraction materials, trace amount of propranolol (1 ng mL-1) in solution can be easily detected after a simple sample preparation. Without the solid phase extraction, the existence of propranolol residues in solution cannot be confirmed with even tandem HPLC-MS/MS analysis. In conclusion, the electrospinning of composite nanofibers containing molecularly imprinted nanoparticles produced a new type of molecular recognition biomimetic matrix, which has potential applications in affinity separation, sensing and diagnostics.
Propranolol uptake (%)
80
imprinted non-imprinted 60
40
20
0 0
10
20
30
40
50
Nanoparticle content (%) Figure 2: Uptake of propranolol with imprinted and non-imprinted composite membranes in a buffer solution
REFERENCES 1. Chronakis, I.S., Milosevic, B., Frenot, A., Ye, L., ‘Generation of molecular recognition sites in electrospun polymer nanofibers via molecular imprinting’. Macromolecules, 39, 357-361, 2006. 2. Chronakis, I. S., Jakob, A., Hagström, B., Ye ,L., ‘Encapsulation and Selective Recognition of Molecularly Imprinted Theophylline and 17beta-Estradiol Nanoparticles within Electrospun Polymer Nanofibers.’ Langmuir, 22, 8960-8965, 2006.
