Blending Chitosan with Polycaprolactone:  Effects on Physicochemical and Antibacterial Properties

Abstract

Chitosan is a well sought-after polysaccharide in biomedical applications and has been blended with various macromolecules to mitigate undesirable properties. However, the effects of blending on the unique antibacterial activity of chitosan as well as changes in fatigue and degradation properties are not well understood. The aim of this work was to evaluate the anti-bacterial properties and changes in physicochemical properties of chitosan upon blending with synthetic polyester poly(epsilon-caprolactone) (PCL). Chitosan and PCL were homogeneously dissolved in varying mass ratios in a unique 77% acetic acid in water mixture and processed into uniform membranes. When subjected to uniaxial cyclical loading in wet conditions, these membranes sustained 10 cycles of predetermined loads up to 1 MPa without break. Chitosan was anti-adhesive to Gram-positive Streptococcus mutans and Gram-negative Actinobacillus actinomycetemcomitans bacteria. Presence of PCL compromised the antibacterial property of chitosan. Four-week degradation studies in PBS/lysozyme at 37 degrees C showed initial weight loss due to chitosan after which no significant changes were observed. Molecular interactions between chitosan and PCL were investigated using Fourier transform infrared spectroscopy (FTIR) which showed no chemical bond formations in the prepared blends. Investigation by wide-angle X-ray diffraction (WAXD) indicated that the crystal structure of individual polymers was unchanged in the blends. Dynamic mechanical and thermal analysis (DMTA) indicated that the crystallinity of PCL was suppressed and its storage modulus increased with the addition of chitosan. Analysis of surface topography by atomic force microscopy (AFM) showed a significant increase in roughness of all blends relative to chitosan. Observed differences in biological and anti-bacterial properties of blends could be primarily attributed to surface topographical changes.

Micromatricial metronidazole benzoate film as a local mucoadhesive delivery system for treatment of periodontal diseases

“…Since the weight loss indicated the extent of surface erosion and/or polymer degradation, it could be concluded that the process of polymer degradation, surface erosion, drug dissolution, and water uptake would occur simultaneously during the release of MET from films. Similarly, Sarasam et al 30 reported an initial weight loss in the PCL-CH blend due to CH, after which no significant changes were observed. These results were consistent with the literature, in which many authors have generally observed that n departs from Fickian diffusion for poorly soluble drugs and that the rate-limiting factor for release is the erosion of the hydrophilic matrix.…”

Development and In Vivo Evaluation of Small-Diameter Vascular Grafts Engineered by Outgrowth Endothelial Cells and Electrospun Chitosan/Poly(ɛ-Caprolactone) Nanofibrous Scaffolds

“…33,34 However, less flexibility in regulating the mechanical properties and biodegradation limits its usage. 35 PCL is an aliphatic polyester that degrades slowly and possesses high tensile and elongation properties, 23 but it has hydrophobicity, neutral charge contribution, limited bioregulatory activity, and susceptibility to bacteria-mediated degradation, 36 which have greatly limited its application as tissue engineering scaffolds. Therefore, blending the bioactive functions of CS with the good mechanical properties of PCL to generate a new hybrid material might show an improvement in biological, mechanical, and degradation properties compared with each individual component.…”

Cell colonization in degradable 3D porous matrices

“…7,64 In a separate study, we blended antibacterial chitosan with PCL and showed that blending compromises the antibacterial property of the material. 113,114 Further, the blend membranes showed better support for fibroblast spreading and proliferation. Surface roughness analysis of blend membranes showed significant increase in roughness relative to chitosan membranes, and observed antibacterial activity could be partially attributed to changed topography.…”