Effect of Porous and Nonporous Polycaprolactone Fiber Meshes on CaCO₃Crystallization Through a Gas Diffusion Method

Abstract

The effect of nonporous (NP-PCL) and porous (P-PCL) fibrous polycaprolactone (PCL) meshes, used as templates, on in vitro CaCO3 crystallization via a gas diffusion (GD) method at 20 °C for 24 h was studied. The nonporous random (NPR-PCL) and porous random (PR-PCL) and the nonporous-aligned (NPA-PCL) and porous-aligned (PA-PCL) fibrous PCL meshes were directly spun on flat or rotary collectors from 18% PCL solutions using ethyl acetate/acetone or ethyl acetate/dimethyl sulfoxide, respectively. The morphology and type of CaCO3 crystal grown on PCL fiber scaffolds were analyzed by Fourier transform infrared spectroscopy (FTIR), contact angle measurements, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS), focused ion beam combined with scanning electron microscopy (FIB-SEM), and X-ray diffraction (XRD) techniques. The PCL fibers distributions affected the nucleation and stabilized calcite and vaterite polymorphs of CaCO3 with different crystal population densities. The crystal density of vaterite was higher than calcite (2:1) when the NPA-PCL and PA-PCL fibers were used as a template, but calcite predominated (2:1) on P-PCL fiber mesh with respect to the NP-PCL fiber mesh. We found that CaCO3 crystals covered the surface of PCL fibers, and some of them grown from inside of the PCL fibers showed that PCL fibers were occluded inside the CaCO3 crystals during the GD crystallization. The nano- and microscale topological features of PCL scaffolds control the diffusion of carbon dioxide (CO2) gas through PCL fiber meshes in the soaking of PCL meshes into a calcium chloride (CaCl2) solution during the GD crystallization affecting subsequently the nucleation and growth of CaCO3 crystals. Indeed, pore size feature of the micrometric A-PCL and nanometric R-PCL fiber meshes affected the intensities of the crystallographic faces of calcite and vaterite as observed by XRD. Contact angle measurements of the aqueous and crystallization liquid droplet on NPR-PCL, PR-PCL and A-PCL fibrous showed different hydrophobic character of the PCL meshes. This study shows the role of the nano- and microscale topological features and the presence of pores on PCL fiber scaffolds on the mineralization behavior of CaCO3 deposited on R-PCL and A-PCL fiber scaffolds, and by this approach various aspects of controlled CaCO3 crystallization such as nucleation and crystal growth of biomaterials based on CaCO3 can be studied with potential biotech applications.

Fabrication of Poly(ε-caprolactone)-Based Biodegradable Packaging Materials with High Water Vapor Barrier Property

“…The glass transition temperature ( T g ), the melting temperature ( T m ), melting enthalpy (Δ H m ), and the degree of crystallinity ( X c ) of PCL and PCL/C18 composites are presented in Figures S1 and S2 and Table S2. The glass transition temperature ( T g ) of pure PCL was about −66.2 °C, which is in accordance with the results reported elsewhere . The C18 dispersed phase limited the movement of the PCL segment, so the T g of PCL was slightly increased.…”

“…The glass transition temperature (T g ) of pure PCL was about −66.2 °C, which is in accordance with the results reported elsewhere. 28 The C18 dispersed phase limited the movement of the PCL segment, so the T g of PCL was slightly increased. The T m decreased slightly from 56 °C of the neat PCL to 54.8 °C of the sample PCL-30, and X c of PCL decreased from 44% to around 35%, indicating that the crystallization of PCL was restricted after the addition of C18.…”

Tailored therapeutic release from polycaprolactone-silica hybrids for the treatment of osteomyelitis: antibiotic rifampicin and osteogenic silicates

“…In other words, it should be both antibacterial and osteostimulative. Driven by the promise of better bone reconstruction, research in the field is investigating many candidate approaches, including drug-loaded synthetic polymers (e.g., polylactic acid, polyglycolic acid), [13][14][15] composites [16][17][18] and hydroxyapatites, silver-based nanotechnologies, quaternary chitosan and therapeutic ion releasing bioactive glasses. 19,20 However, despite their promising results in the laboratory, most of these technologies still lack significant clinical data to confirm their efficacy.…”