[Show abstract][Hide abstract] ABSTRACT: With the advances in the understanding of cell interactions with their microenvironments, biomaterials mimicking native microenvironments are being developed to display and deliver cell-regulatory signals in a precise and near-physiological fashion, which are used to regulate cell behavior and fate both in vitro and in vivo. Such biomaterials can provide the necessary microenvironmental cues based on chemistry, topography, mechanics, and molecule delivery. This has significantly promoted the applications of biomaterials to tissue engineering and disease treatment. This report has summarized the recent progress made in the field by focusing on native microenvironment-mimetic biomaterials utilized as tissue scaffolding and other implant devices. In particular, material properties that direct cellular behavior through controlled presentation of specific cues in time or in space, such as the material composition and material surface functionality, structure, topology, hydrophilicity/hydrophobicity, charge and energy, as well as the material topology density and mechanics, have been discussed in great detail. It is anticipated that the synergy of cell biology and modern material technologies will have a profound impact on the design and development of new generations of biomaterials.
[Show abstract][Hide abstract] ABSTRACT: Collagen and chitosan blends were fabricated into ultrafine fibers to mimic the native extracellular matrix (ECM). So far less mechanical property investigation of electrospun fibers has been reported because of the small dimensions of micro and nanostructures that pose a tremendous challenge for the experimental study of their mechanical properties. In this paper, the electrospun collagen–chitosan complex single fibers and fibrous membrane were collected and their mechanical properties were investigated with a nano tensile testing system and a universal materials tester, respectively. The mechanical properties were found to be dependent on fiber diameter and the ratio of collagen to chitosan in fibers. Fibers with a smaller diameter had higher strength but lower ductility due to the higher draw ratio that was applied during the electrospinning process. For the electrospun single fibers, the fibers demonstrated excellent tensile ductility at chitosan content of 10% and 20% and the highest tensile strength and Young's modulus at chitosan content from 40% to 60%. For the electrospun fibrous membrane, the ultimate tensile strength of the fibrous membrane decreased with the increase of chitosan content in fibers and the trend in the ultimate tensile elongation is similar to that of the single fiber.
No preview · Article · Oct 2009 · Materials Science and Engineering C