Biomaterials Based on Electrospun Chitosan. Relation between Processing Conditions and Mechanical Properties

Abstract

In this paper, it is shown that pure chitosan nanofibers and films were prepared with success in 0.5 M acetic acid as solvent using poly (ethylene oxide) (PEO) at different yields, allowing electrospinning of the blends. After processing, a neutralization step of chitosan followed by water washing is performed, preserving the initial morphology of chitosan materials. The influence of the yield in PEO in the blend on the degree of swelling and hydrophilicity of films and nanofibers is demonstrated. Then, the mechanical behavior of blended nanofibers and films used as reference are determined for small stress applied in the linear domain by DMA and by uniaxial traction up to rupture. The dried and wet states are covered for the first time. It is shown that the mechanical properties are increased when electrospinning is performed in the presence of PEO up to a 70/30 chitosan/PEO weight ratio even after PEO extraction. This result can be explained by a better dispersion of the chitosan in the presence of PEO.

Characterization of Poly(Ethylene Oxide) Nanofibers—Mutual Relations between Mean Diameter of Electrospun Nanofibers and Solution Characteristics

“…Intensive study of PEO behavior during the electrospinning process has been undertaken due to this fact and because of the excellent biodegradability, biocompatibility, and non-toxicity. These attributes also reflect PEO nanofiber applications in biomedicine and the food industry [7][8][9][10] apart from the above already mentioned improvements in spinnability in combination with chitin or chitosan [11][12][13][14], keratin [15,16], silk [17,18] and other materials.…”

Production of Chitosan/Hyaluronan Complex Nanofibers. Characterization and Physical Properties as a Function of the Composition

“…Acid formic solvent was selected due to easier feasibility to produce nanofibers by electrospinning compared to acetic acid used previously [ 4 , 5 ]. Whatever the W/FA ratio (mainly over 25/75), electrospinning allows to process chitosan alone, HA/PEO, as well as the chitosan/hyaluronic acid complex.…”

“…For determination of the mechanical properties on films after thermal treatment, the complexes and the treated CS were directly stabilized in PBS buffer but for CS before thermal treatment, it was necessary to firstly neutralized CS in alkaline medium before PBS immersion as suggested beforehand [ 4 , 5 ]. From data in Figure 11 , it is concluded that the material is able to be manipulated only when R c ≥ 1.8 corresponding to lower values of swelling and solubility.…”

“…The large area to volume ratio and high porosity of electrospun fibers promotes the adhesion of cells and cell growth [ 2 ]. This technique was previously used in our laboratory to produce pure and stable chitosan fibers [ 4 , 5 ]. The main electrospinning parameters were studied on chitosan/polyethylene oxide (PEO) blends in acetic acid at 50% [ 6 ].…”

Biomaterials from Chitosan Processed by Electrospinning

“…After electrospinning, nanofibers under protonated form of chitosan are made of chitosan/PEO blends. Pure chitosan nanofibers are recovered by immersion in ethanol/water 70/30 (v/v) containing potassium carbonate (0.2 M) and washing in water [17,18]. An example of the nanofibers obtained is given in figure 4.…”