Aliphatic Chain Modification of Collagen Type I: Development of Elastomeric, Compliant, and Suturable Scaffolds

Abstract

Collagen type I is one of the most suitable natural biomaterials for constructing tissue-engineering scaffolds. Despite their biocompositional similarities to physiological tissues, these scaffolds lack host specific and matching mechanical properties. While it is possible to enhance their stiffness by cross-linking, it often compromises their abilities to expand or strain under minimal stress, that is, compliance (inverse of stiffness). Here, we report a simple, inexpensive, cross-linking-and elastinfree collagen-based material composition for developing elastomeric scaffolds that are highly compliant, soft yet strong, and suturable, therefore, clinically attractive. Our strategy utilizes room-temperature modification of collagen type I scaffolds with linear aliphatic chains of various lengths (C7−C18). In particular, dodecenylsuccinic anhydride (size: C12, DDSA) modified scaffolds elongated up to 400% of its initial length compared to only ∼20% for collagen-control within the applied tensile stress of 0.2 MPa without breaking. Furthermore, the suture retention strength value increased to 60 g-force from 30 g-force for collagen control. We confirmed that the C12-modified material remained structurally stable at the physiological temperature (37 °C) with a tan δ value of ∼0.3, similar to collagen control; however, tan δ increased sharply for C12-modified collagen above 42 °C, compared to 59 °C for collagen control. To understand the mechanism of hyperextensibility, we studied the morphology of the resultant material by transmission electron microscopy (TEM), which showed an altered microstructure of C12-modified collagen scaffolds. While the partially C12-modified sample had a mixture of typical collagen type I triple helix and diffused gelatinized random coil-like configuration, the fully modified samples showed thick wrinkled and entangled ribbon-like microstructures, which was different than that of thermally denatured gelatin. We further confirmed that the resultant material allowed cell growth in vitro and in vivo in a subcutaneous mouse model.

Adhesive and biodegradable membranes made of sustainable catechol-functionalized marine collagen and chitosan

“…The comparison between the 1 H NMR spectra of the individual components, i.e. Coll I and 3,4-DB, and their conjugate showed that the signal of the proton from the aldehyde group of 3.4-DB (δ = 9.5 ppm) disappear in the Coll-Cat spectrum and the peaks corresponding to the aromatic protons of 3,4-DB (δ = 7-7.5 ppm) and Coll I as well as the protons associated with the aliphatic group from Coll I were shifted, which indicates the formation of the conjugate [31].…”

Development of Enzymatic-Resistant and Compliant Decellularized Extracellular Matrixes via Aliphatic Chain Modification for Bladder Tissue Engineering

“…To study scaffold morphology, SEM was performed in accordance with an earlier published protocol. 29 In brief, scaffolds were fixed overnight at 4 °C in 2.5% glutaraldehyde in 100 mM sodium cacodylate buffer and 0.1% tannic acid (pH 7.2−7.4). Samples were washed with a 100 mM sodium cacodylate buffer with 3% sucrose and 3.0 mM MgCl 2 .…”

“…The percentage of free amine groups in dECMs was determined using 2,4,6-trinitrobenzenesulfonic acid (TNBS) assay, as described in our previous work. 29 Briefly, unmodified and modified dECMs were dried, weighed, and reacted for 2 h with a mixture of 500 μL of 4.0% w/v NaHCO 3 aqueous solution and 500 μL of 0.05% w/v TNBS at 40 °C. The reaction was quenched with 6 M HCl and left for reaction for 1.5 h at 60 °C.…”