Electrospinning of in situ crosslinked collagen nanofibers

Abstract

A simple one-step approach to electrospin Type I collagen in the presence of the chemical crosslinking agents 1-ethyl-3-(3-dimethyl-aminopropyl)-1-carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) has been developed to generate water-insoluble collagen nanofiber scaffolds without the need for post-crosslinking. SEM images indicate that fibrous surface morphology of collagen scaffolds was well retained after the in situ crosslinking process and following water treatment. The resultant collagen demonstrated a similar uniaxial tensile behavior of native tissue in mechanical testing.

Local mechanical response in semiflexible polymer networks subjected to an axisymmetric prestress

“…Relaxing the hypoelastic assumption to allow finite strains should be possible following established methods [31,46] and would allow direct comparison to data for collagen scaffolds used in tissue engineering [29,30], which exhibit a characteristic J-shaped curve for strains up to 100%. Fitting the model to such curves will allow quantities related to the network structure to be extracted.…”

“…Consider applying an anisotropic prestress to an isotropic fiber network. This prestress can emerge spontaneously due to intracellular mechanisms [28] or from the sustained uniaxial strains employed to check the nonlinear properties of nanofiber scaffolds in tissue engineering [29,30], for example. If the magnitude of the stress is sufficient to place some fraction of fibers into the nonlinear regime of their force-extension curves, the stiffness of individual fibers with respect to perturbations about this prestressed state will depend on their orientation, as schematically represented in Fig.…”

Structure-property-function relationships in triple-helical collagen hydrogels

“…In order to investigate whether variation of molecular parameters could induce changes in Collagen denaturation temperature (T d ) is related to the unfolding of collagen triple helices into randomly-coiled chains; it is therefore expected to be highly affected by the formation of a covalent network [2]. Table I seems to be directly related to changes of crosslinking degree in the hydrogel network.…”

“…Also in light of its unique molecular organization, collagen has been widely applied for the design of vascular grafts [1], fibrous materials for stem cell differentiation [2], biomimetic scaffolds for regenerative medicine [3], and tissue-like matrices for hard tissue repair [4]. However, collagen properties are challenging to control in physiological conditions, mainly because its hierarchical organization and chemical composition in vivo can only be partially reproduced in vitro.…”

In Pursuit of Functional Electrospun Materials for Clinical Applications in Humans

“…By crosslinking during the electrospinning process, greater control over the cross-linking reaction can be maintained and the need for post-processing is eliminated. A common strategy is adding cross-linking agents into the precursor solution immediately before electrospinning to ensure that the reaction progresses with an appropriate timescale by controlling reactant concentrations [90][91][92][93]. The reaction kinetics dictate transient properties in the electrospinning solution, such as a dramatic increase in solution viscosity as the reaction progresses, which can result in a change over time of nanofiber properties such as fiber diameter and degradation timescale [90,92].…”