Biocompatible silk fibroin scaffold prepared by reactive inkjet printing

Abstract

It has recently been shown that regenerated silk fibroin (RSF) aqueous solution can be printed using an inkjet printer. In this communication, we demonstrate an alternative reactive inkjet printing method that provides control over RSF crystallinity through b-sheet concentration. A biocompatible film has successfully been produced through the alternate printing of RSF aqueous solution and methanol using reactive inkjet printing. Control over the formation of the bsheet structure was achieved by printing different ratios of RSF to methanol and was confirmed using Fourier Transform Infra Red spectroscopy. The biocompatibility of the printed silk scaffold was demonstrated by the growth of fibroblast cells upon its surface.Silk is a versatile, natural material favoured for its mechanical strength, excellent biocompatibility, adaptable biodegradability [1, 2], easy processing [3] and flexible structural modification [4]. Silk has a long history of use [5]; recently, regenerated silk fibroin (RSF) has been used as a building block for the fabrication of biomedical devices [3]. RSF structures are commonly produced with a casting method; however, additive manufacture applications offer a greater control over RSF film surfaces which can be advantageous for controlling cell growth. Current additive manufacture applications are mainly focused on producing individual silk fibres such as electrohydrodynamic printing [6] and electrospinning [7]. Different silk polymorphs, silk I, silk II and silk III, have been observed. Silk I, which is the water-soluble state seen prior to crystallisation, is composed of ahelix and amorphous chains. Silk II contains an extended b-sheet structure and appears after spinning [3]. Silk III assembles at an air (or oil)/water interface [8], but only silk I and silk II are of interest in this work. Water-soluble silk I can be converted to insoluble silk II by exposure to methanol, as reported by Huemmerich et al. [9]. The asymmetrical b-sheet structures of Silk II consist of hydrogen side chains from glycine on one side and methyl side chains from alanine on the other side. The methyl groups interact with hydrogen groups of opposing b-sheets to form

Advanced Polymers for Three-Dimensional (3D) Organ Bioprinting

“…It is an emerging new interdisciplinary field that needs cooperation of many fields of science and technology, such as biomaterials, biology, physics, chemistry, computers, mechanics, bioinformatics, and medicine ( Figure 2). During the last 16 years, a large variety of 3D bioprinting technologies have been exploited, which has led to the emergence of fully automatic manufacturing of bioartificial organs for wide biomedical applications, such as high-throughput drug screening, controlled cell transplantation, customized organ repair/regeneration/replacement/restoration, pathological mechanism analysis, metabolism model establishment, and living tissue/organ cryopreservation [10][11][12][13][14][15][16][17][18][19][20]. Based on the working principles, these technologies can be classified into four major groups: inkjet-based, extrusion-based, laser-based, and their combinations ( Figure 3).…”

“…Each of the former three groups has advantages and disadvantages in bioartificial organ manufacturing. [10][11][12][13][14][15][16][17][18][19][20]. Images reproduced with permission from [10][11][12][13][14][15][16][17][18][19][20].…”

“…In this article, several advanced polymers with excellent biocompatibility, biodegradability, 3D printability, and structural stability are reviewed. The challenges and perspectives of polymers for rapid manufacturing of complex organs, such as the liver, heart, kidney, lung, breast, and brain, are outlined.2 of 25 computer-aided design (CAD) models [10][11][12][13]. Patient-specific organ image data, such as computerized tomography (CT) and magnetic resonance imaging (MRI), can be easily transferred into CAD models for customized organ manufacturing with predefined geometrical shapes, biomaterial constituents, and physiological functions [14][15][16][17].high-throughput drug screening [38][39][40], in vivo biocompatibilities of implanted biomaterials [41][42][43].…”

“…2 of 25 computer-aided design (CAD) models [10][11][12][13]. Patient-specific organ image data, such as computerized tomography (CT) and magnetic resonance imaging (MRI), can be easily transferred into CAD models for customized organ manufacturing with predefined geometrical shapes, biomaterial constituents, and physiological functions [14][15][16][17].…”

Reactive inkjet printing of polyethylene glycol and isocyanate based inks to create porous polyurethane structures

“…Then, the mixing and the chemical reaction take place on the substrate's surface, forming the desired chemical structure. Silk micro‐rockets, as well as silk fibroin scaffolds, have successfully been created using the full RIJ approach . In both the cases, a silk ink is reacted with a methanol ink in order to transform the soluble random coil silk structure into the insoluble beta‐sheet structure.…”