Preparation and characterization of poly(ethylene glycol)-block-poly[epsilon-(benzyloxycarbonyl)-L-lysine] thin films for biomedical applications

作者：Izunobi Josephat U; Geever Luke M; Higginbotham Clement L^*

来源：Polymer Bulletin, 2014, 71(7): 1691-1709.

DOI：10.1007/s00289-014-1149-7

• As-cast thin films
• Biopolymers
• Diblock copolymers
• Equilibrium structures
• Polypeptides
• Surface topography

The nanoscale architectures evident in the thin films of self-assembling hybrid block copolymers-which are tailored to inherit the advantageous properties of their constituent synthetic (homo)polymer and polypeptide blocks-have continued to inspire a variety of new applications in different fields, including biomedicine. The thin films of symmetric hybrid block copolymer, alpha-methoxy-poly(ethylene glycol)-block-poly[epsilon-(benzyloxycarbonyl)-l-lysine], MPEG(112)-b-PLL(Z)(17), were prepared by solvent casting in five different solvents and characterized using Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy, Thermogravimetric analysis, Derivative Thermogravimetric analysis, Differential Scanning Calorimetry, Contact Angle goniometry, Wide-Angle X-ray Diffraction, and Scanning Electron Microscopy. Film thickness was estimated to be 51 +/- A 23 mu m by the "step-height" method, using a thickness gauge. Although no significant change to the block copolymer's microstructure was observed, its solvent-cast films displayed divergent physical and thermal properties. The resulting cast films proved more thermally stable than the bulk but indicated greater block miscibility. Additionally, the thin films of MPEG(112)-b-PLL(Z)(17) preserved the microphase separation exhibited by the bulk copolymer albeit with appreciable loss of crystallinity. The surface properties of the polymer-air interface were diverse as were the effects of the casting solvents. Oriented equilibrium morphologies are also evident in some of the as-cast thin films.

• 出版日期2014-7