Protein-Drug Interaction in the Nanocomposites Prepared by UV And IR Pulsed Laser Deposition
- PDF / 334,188 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 91 Downloads / 303 Views
KK3.11.1
PROTEIN-DRUG INTERACTION IN THE NANOCOMPOSITES PREPARED BY UV AND IR PULSED LASER DEPOSITION J. Sagawa*, S. Nagare**, M. Senna* * Keio University, Faculty of Science and Technology, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan **Nara Machinery Co., Ltd., 2-5-7 Jonan-jima, Ohta-ku, Tokyo, 143-0002, Japan ABSTRACT Protein (bovine serum albumin; BSA)-drug (indomethacin; IM) nanocomposites were prepared by pulsed laser deposition (PLD) at two wavelengths, infrared (1064nm) and ultraviolet (266nm), from uniformly dispersed mixture of BSA and IM as a target. Composite particulates under 50nm were obtained with the coexistence of larger agglomerates over 200nm. Primary structure of BSA is preserved after laser irradiation by both wavelengths. Effects of electronic and vibrational excitation by UV and IR laser respectively on the secondary structure of the nanocomposites were examined by Fourier transform infrared spectroscopy (FT-IR). Chemical shift towards lower wavenumber and a broadening of the amide I band due to PLD treatment were observed by FT-IR. From curve fitting of the amide I into five components, we found the decrease in the ratio of α-helical / β-sheet components with increasing the laser fluence. secondary structure of BSA is more sensitive to the laser fluence than the wavelength.
The
INTRODUCTION Pulsed laser deposition (PLD) is one of the most popular preparation methods for thin films and fine particles in the nanometer regime [1,2]. Recently, this technique has been extended to organic materials including macromolecules such as proteins [3,4]. Important parameters to control the chemical states of the deposited organic materials are the laser fluence and wavelength, which correspond to the energy of the total irradiation and a single photon, respectively. In this work, 266nm (UV) and 1064nm (IR) laser beams were used with varying fluence from 5J/cm2 to 18J/cm2, to examine the effects of wavelength and fluence on the chemical states of the deposited materials. UV laser is known to enhance primarily the electronic excitation, and 1064nm laser to vibrational excitation [5]. We compare these two excitation mechanisms by using preliminary conjugated target of γ-indomethacin (1-(p-chlorobenzoyl)-5-mehoxy-2 -methylindole-3-acetic acid; denoted as IM) and bovine serum albumin (BSA). Preparation of nanocomposites particulates of IM, which are very sparingly soluble in water, with water soluble protein, BSA, is desired for increasing the bioavailability and improving the drug delivery
KK3.11.2
system [6]. For this purpose, preservation of the primary and secondary structure of the protein after laser irradiation is important to maintain its function. Effects of the laser wavelength and fluence to the primary and secondary structures of BSA are studied by matrix laser desorption ionization time of flight mass spectrometer (MALDI-TOFMS) and FT-IR, respectively. We also discuss the change in the ratio of α-helical structure and β-sheet structure in BSA by the PLD operation. EXPERIMENTAL BSA and
Data Loading...
