Properties of melt processed chitosan and aliphatic polyester blends

Abstract

Chitosan was melt blended with poly-caprolactone (PCL), poly(butylene succinate) (PBS), poly(lactic acid) (PLA), poly(butylene terephthalate adipate) (PBTA), and poly(butylene succinate adipate) (PBSA). For the chitosan/PBS blend, the amount of chitosan was varied from 25% to 70% by weight. The remaining polyesters had 50% of chitosan by weight. Addition of chitosan to PBS or PBSA tends to depress the melting temperature of the polyester. The crystallinity of the polyesters (PCL, PBS, PBSA) containing 50% chitosan decreased. Adding chitosan to the blends decreased the tensile strength but increased the tensile modulus. Chitosan displayed intermediate adhesion to the polyester matrix. Microscopic results indicate that the skin layer is polyester rich, while the core is a blend of chitosan and polyester. Fractured surface of chitosan blended with a high T g polymer, such as PLA, displayed a brittle fracture. Blends of chitosan with PCL, PBTA, or PBSA display fibrous appearances at the fractured surface due to the stretching of the polymer threads. Increasing the amount of chitosan in the blends also reduced the ductility of the fractured surface. The chitosan phase agglomerated into spherical domains or were clustered into sheaths. Pull-out of chitosan particles is evident in tensile-fractured surfaces for blends of chitosan with ductile polymers but absent in the blends with PLA. PBS displays a less lamellar orientation when compared to PCL or PBSA. The orientation of the polyesters (PCL, PBSA) does not seem to be affected by the addition of chitosan. The two main diffraction peaks observed using WAXS are unaffected by the addition of chitosan.

Osteogenic Differentiation of Human Bone Marrow Mesenchymal Stem Cells Seeded on Melt Based Chitosan Scaffolds for Bone Tissue Engineering Applications

“…The processing methodology is entirely melt based, thus avoiding the limitations of solvent-based processing, and it is described in detail elsewhere. 23 Briefly, chitosan was melt blended with polybutylene succinate (PBS; 50/50 wt %) in a twinscrew extruder. The extrudate was grinded into powder and further processed into microfibers, using a microextruder.…”

“…To overcome this problem, we propose a novel methodology to process chitosan by compounding this material with biodegradable aliphatic polyesters. 23 The blend combines the favorable biological properties of chitosan with the good mechanical properties and processability of polyesters, [23][24][25][26][27][28][29][30] leading to a chitosan based material with adjustable properties for tissue engineering applications. [27][28][29][30] The purpose of the present work is to evaluate the performance of the developed microfiber mesh scaffolds.…”

Assessment of the Suitability of Chitosan/PolyButylene Succinate Scaffolds Seeded with Mouse Mesenchymal Progenitor Cells for a Cartilage Tissue Engineering Approach

“…This pH-dependent solubility provides a convenient mechanism for processing under mild conditions. 25 Chitosan is reported to be nontoxic, biodegradable, and biocompatible, 26 and has structural similarities to glycosaminoglycans, which are structural components of the cartilage extracellular matrix. 27 It serves different applications, and its use ranges from the food industry to the biomedical and pharmaceutical fields.…”

“…Its conjugation with chitosan aims at providing mechanical support to the scaffold, which should be advantageous considering the clinical scenario of constant load-bearing efforts in articular cartilage. Little research has been conducted in the melt blending of synthetic polyesters and chitosan, 26 and the preliminary results described herein for their use as potential scaffolds for cartilage regeneration are important. The herein developed chitosan and polybutylene succinate (C-PBS) scaffolds were seeded with cells originated from a mouse mesenchymal stem cell line (BMC9) 32 and cultured under chondrogenic inductive conditions, in order to assess their suitability for cartilage tissue engineering approaches.…”

Three dimensional microstructuring of biopolymers by femtosecond laser irradiation

“…Useful properties, i.e., improved resistance to degradation by naturally occurring enzymes, can be obtained by blending natural and synthetic polymers. 20 In the present study, sequences of 800 nm, 30 fs pulses are used to create a pattern of laser affected spots with micrometer dimensions at increasing depths below the surface in samples of transparent polymers and biopolymers with different water contents and mechanical properties, such as gelatine, chitosan, synthetic polyvinyl pyrrolidone polymer ͑PVP͒, and of biopolymer-polymer blends. The effects of self-focusing and optical aberration are discussed as major factors that control the morphology of the laser created spots inside the material.…”