ABSTRACT
Poly N-vinylcaprolactam-co-acrylamidophenylboronic acid p(NVCL-co-AAPBA) was prepared from N-vinylcaprolactam (NVCL) and 3-acrylamidophenylboronic acid (AAPBA), using 2,2-azobisisobutyronitrile (AIBN) as initiator. The synthesis and structure of the polymer were examined by Fourier Transform infrared spectroscopy (FT-IR) and (1)H-NMR. Dynamic light scattering (DLS), lower critical solution temperature (LCST) and transmission electron microscopy (TEM) were utilized to characterize the nanoparticles, CD spectroscopy was used to determine if there were any changes to the conformation of the insulin, and cell and animal toxicity were also investigated. The prepared nanoparticles were found to be monodisperse submicron particles and were glucose- and temperature-sensitive. In addition, the nanoparticles have good insulin-loading characteristics, do not affect the conformation of the insulin and show low-toxicity to cells and animals. These p(NVCL-co-AAPBA) nanoparticles may have some value for insulin or other hypoglycemic protein delivery.
Subject(s)
Boronic Acids/chemistry , Caprolactam/analogs & derivatives , Drug Delivery Systems , Glucose/analysis , Insulin/administration & dosage , Insulin/pharmacology , Nanoparticles/chemistry , Polymers/chemistry , Temperature , Animals , Blood Glucose/metabolism , Caprolactam/chemistry , Cell Death/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Circular Dichroism , Female , Humans , Hydrodynamics , Hydrogen-Ion Concentration , Male , Mice , Micelles , Molecular Weight , Nanoparticles/ultrastructure , Particle Size , Proton Magnetic Resonance Spectroscopy , Rats , Spectroscopy, Fourier Transform Infrared , Static ElectricityABSTRACT
Polyvinyl alcohol (PVA) nanofibers loaded with curcumin or its ß-cyclodextrin (CD) inclusion complex were successfully prepared using an electrospinning process. The influence of curcumin or CD-curcumin complex content on fiber formation and quality was investigated. X-ray diffraction and differential scanning calorimetry analyses of the fibers, together with electron microscope evidence, demonstrated that curcumin is likely to be present as crystalline aggregates in the fibers, while its CD complex is more evenly distributed. (1)H NMR analysis indicated that the chemical structure of curcumin was preserved during the electrospinning process. Thermogravimetric analysis demonstrated that inclusion into nanofibers enhanced the thermal stability of curcumin. In vitro dissolution tests showed that the drug release profiles of the PVA/curcumin and PVA/complex fibers were different, with release from the latter occurring more rapidly. Release from both fiber types was found to be largely governed by a diffusion-controlled mechanism; two sequential stages for drug release were observed.
