A versatile three-dimensional foam fabrication strategy for soft and hard tissue engineering

Abstract

The fabrication strategies of three-dimensional porous biomaterials have been extensively studied and well established in the past few decades, yet the biocompatibility and versatility of porous architecture preparation is still lacking. Herewith, we present a novel and green 3D porous foam fabrication technique for both soft and hard engineering. By utilizing the gelatinization and retrogradation properties of starches, stabilized porous constructs made of various building blocks, from living cells to ceramic particles, were created for the first time. In soft tissue engineering applications, 3D cultured tissue foam (CTF) with controlled cell release properties was developed, and foams constituting osteoblasts, fibroblasts and vascular endothelial cells all exhibited high mechanical stability and preservation of cell viability or functions. More importantly, the CTF achieved sustained self-release of cells controlled by serum concentration (containing amylase) and the released cells also maintained high viability and functions. In the context of hard tissue engineering applications, ceramic/bioglass (BG) foam scaffolds were developed by a similar starch-assisted foaming strategy where the resultant bone scaffolds of hydroxyapatite (HA)/BG and Si 3 N 4 /BG possessed >70% porosity with interconnected macropores (sizes 200∼400 μm), fine pores (sizes 1∼10 μm) and superior mechanical properties despite the high porosity. Additionally, in vitro and in vivo evaluations of the biological properties revealed that porous HA/BG foam exhibits the desired biocompatibility and osteogenesis. The in vivo study indicated new bone ingrowth after 1 week and significant increases in new bone volume after 2 weeks. In conclusion, the presented foaming strategy provides opportunities for biofabricating CTF with different cells for different target soft tissues and preparing porous ceramic/ BG foams with different material components and high strengths, showing great versatility in soft and hard tissue engineering.

Polydopamine-modified poly(l-lactic acid) nanofiber scaffolds immobilized with an osteogenic growth peptide for bone tissue regeneration

“…2,3 In the past few decades, biomedical implants based on metals, polymers, ceramics and their composites or hybrids have been extensively studied and reported. [4][5][6][7][8][9][10][11][12][13][14] Based on the diverse physicochemical properties of different materials, various fabrication strategies have been developed involving 3D printing, eco-friendly supercritical uid technology, electrospinning, etc. [15][16][17][18] For instance, 3D printing has been widely utilized to fabricate polymer-based scaffolds with desired porous architectures in a precise way.…”

Biodegradable cell‐laden starch foams for the rapid fabrication of 3D tissue constructs and the application in neural tissue engineering

“…Similar results have been obtained in our previous study, in which osteoblasts, fibroblasts, and vascular endothelial cells were encapsulated in the starch foams respectively, and all exhibited high viability. 24 As the strategy for fabrication of cellladen starch foams has great versatility, it can be assumed that other type of cells such as neural stem cells and mesenchymal stem cells can also be encapsulated in the foams for 3D tissue construct or cell therapy. For tissue engineering applications, encapsulated cells in the biomaterials or scaffolds also need to be released from the materials to designated locations, allowing subsequent adhesion and proliferation.…”

“…By utilizing the unique gelatinization property of starch molecules, the in situ formed starch foams with tunable architecture have been prepared in a green and biological‐friendly manner. Due to that the α‐amylase in serum can digest the starch binder in the foams, cells encapsulated in the foams can be released during the degradation process of the starch foams . In addition, the potential application of the cell‐laden starch foams in neural tissue engineering has been initially investigated.…”

“…Due to that the α-amylase in serum can digest the starch binder in the foams, cells encapsulated in the foams can be released during the degradation process of the starch foams. 24 In addition, the potential application of the cell-laden starch foams in neural tissue engineering has been initially investigated. Schwann cells, one of the most used cells for cellbased therapies in central and peripheral nerve injuries, 25,26 were encapsulated in the starch foams.…”

Effects of Concentrated Growth Factor on the Proliferation, Migration, and Osteogenic Differentiation of Rat Bone Marrow Mesenchymal Stem Cells: An in vitro study

“…BMSCs have played a key role in cell-based therapy and tissue engineering due to the multiple differentiation potential of them in resent years [19][20][21]. BMSCs are the preferred candidate cell resource for bone tissue engineering and cell-based therapies because they can differentiate into bone-forming osteoblasts and play a crucial role in bone regeneration [22].…”