Processing Methods of Ultrathin Poly(ε-caprolactone) Films for Tissue Engineering Applications

Abstract

Ultrathin poly(epsilon-caprolactone) (PCL) films were fabricated through biaxially drawn films made from three different methods, namely, spin casting, 2-roll milling, and solution casting. Biaxial drawn spin cast films yield thickness of 1.2 microm which is 9 and 12 times thinner that 2-roll mill and solvent cast films, respectively. The films fabricated were found to exhibit different drawing ratios. 2-roll mill film exhibits the highest drawing ratio of 4 x 4 while spin cast films can only draw up to a ratio of 2 x 2. The morphology of the films, studied using a polarized microscope and atomic force microscope, showed fine fibrillar networks of different thicknesses. Biaxially drawn 2-roll mill and solvent cast films showed thicker fibrils as compared to those for the spin cast films. Such a difference can be attributed to larger spherulites caused by slower cooling rates during melt pressing for both 2-roll mill and solvent cast films and smaller spherulites because of fast cooling during evaporation for spin cast films. Thermal analysis through differential scanning calorimetry revealed a slight increase in the peak-melting temperature after biaxial drawing. A drop in percentage crystallinity was also noted. The result of the water vapor transmission rate (WVTR) was found to be dependent on fabrication techniques that determine the spherulites formation. It was also found that the WVTR was inversely proportional to the thickness of the films. Tensile strength and modulus of the films showed significant improvements after biaxial stretching. By identifying the unique strengths of each individual PCL film produced via different techniques, it is possible to apply to different areas of membrane tissue engineering such as dermatology, ophthalmology, vascular graft engineering, and soft tissue regeneration.

Enhancing mesenchymal stem cell response using uniaxially stretched poly(ε-caprolactone) film micropatterns for vascular tissue engineering application

“…Briey, solvent-cast PCL lm (SC-PCL) was generated through casting PCL solution (2 wt% in dichloromethane) onto a glass mold and evaporating the solvent in a fume hood. 24 Cast-stretch PCL lm (CS-PCL) was obtained using an in-house developed machine via cast extrusion. 25 Heat-press PCL lm (HP-PCL) was generated through pressing PCL solid mass at 80 C and 300 MPa.…”

Mechanical properties and structure development in poly(butylene succinate)/organo-montmorillonite nanocomposites under uniaxial cold rolling

“…Cold rolling action decreased the " c due to the destruction of crystalline regions as large lamellae (folded chain structures) were subjected to rolling to form microfibrils (extended chain structures). The transition from folded chain structures to extended chain structures after cold rolling resulted in thinner lamellae and lower crystallinity [33].…”

Relationship between micro-porosity, water permeability and mechanical behavior in scaffolds for cartilage engineering

“…26 27 . PCL is a well used material for tissue engineering applications, with innumerous fabrication methods 28 29 such as for example selective laser sintering 30 , solvent casting films 31 32 , blends with PLA 33 15 , nanocomposite scaffolds 34 35 22 36 21 , electrospinning 37 38 39 40 , spin coating 41 , hyaluronic acid coating 42 43 or hot pressing technique 44 45 .…”