A thin layer of PCL-��-CD film was formed, which was soaked in and washed multiple times with water to remove any unthreaded ��-CD. PCL-��-CD IC was further characterized selleck compound by 1H-NMR (300 or 400 MHz; Bruker), wide-angle X-ray diffraction (WAXD) from 2�� = 5�� to 35�� (PANalytical MPD Pro Diffractometer, Cu-K�� radiation; PANalytical B.V.) and Fourier transform infrared-attenuated total reflectance (FTIR-ATR) (Bruker, Vector 22 with a Pike Miracle ATR attachment) spectroscopy within a range of wavenumber 700�C3,800 cm?1. WAXD and FTIR-ATR were also performed on PCL only and ��-CD only samples, as controls. Electrospinning of PCL and PCL-��-CD IC nanofibers PCL was dissolved in a mixture of dichloromethane (DCM) and dimethyl sulfoxide (DMSO) (17/9, v/v) at a concentration of 10% (w/v).
59 The solution was drawn into a 1 mL syringe (Norm-Ject, Henke-Sass Wolf GmbH) with a 30 G needle (Becton, Dickinson and Co.) and electrospun at 8 kV and 5 mL/h. PCL-��-CD was dissolved in a mixed solvent of DCM and DMSO (2/3, v/v) at a concentration of 10% (w/v) and filled into the same kind of syringe and needle. The PCL-��-CD fibers (605 �� 85 nm, n = 100 nm) were electrospun at 5.5 kV and 6 mL/h to obtain fibers with similar diameter to those of PCL (617 �� 170 nm, n = 100). Fibers were collected onto aluminum foil covered with 15 mm diameter microscope coverslips (Thermo Fisher Scientific), which were kept at a distance of 16 cm from the tip of the syringe needle. Electrospun fibers-covered coverslips were cut off from the aluminum foil and kept for further use.
Before seeding with cells, fiber samples were put into 24-well plates and sterilized by overnight UV exposure. Fluorescamine conjugation to PCL-��-CD IC fibers PCL and PCL-��-CD fibers on microscope coverslips (dia ~15 mm) were soaked in DMSO containing N,N��-carbonyldiimidazole (N,N��-CDI; Sigma-Aldrich) at room temperature. Ethylenediamine (Sigma-Aldrich) was added to these fibers, and after 30 min of shaking, both fibers were taken out, washed with fresh DMSO and soaked in fluorescamine-DMSO solution. After subsequent washing with fresh DMSO and water, fluorescence images of two different samples were taken on a Nikon DXM1200 microscope under both bright field and UV light. Polystyrene nanobeads conjugation to PCL-��-CD IC fibers PCL and PCL-��-CD fibers were soaked in N,N��-CDI/DMSO solution while undergoing shaking.
After 1 h, both fibers were taken out, washed with fresh DMSO and soaked in DMSO containing polystyrene nanobeads with amine functional groups (0.2 ��m dia; Invitrogen?, Life Technologies). After shaking for ~4 h, fibers were washed with ethanol to remove any unconjugated Batimastat nanobeads that had settled on the fiber surface. The fibers on coverslips were placed vertically in both DMSO and ethanol to avoid any gravitational settling or physical adsorption of beads on the fibers. These fibers were vacuum dried, sputter coated (Anatech Hummer 6.