Hierarchical porous materials for tissue engineering

Author(s):  
Julian R Jones ◽  
Peter D Lee ◽  
Larry L Hench

Biological organisms have evolved to produce hierarchical three-dimensional structures with dimensions ranging from nanometres to metres. Replicating these complex living hierarchical structures for the purpose of repair or replacement of degenerating tissues is one of the great challenges of chemistry, physics, biology and materials science. This paper describes how the use of hierarchical porous materials in tissue engineering applications has the potential to shift treatments from tissue replacement to tissue regeneration. The criteria that a porous material must fulfil to be considered ideal for bone tissue engineering applications are listed. Bioactive glass foam scaffolds have the potential to fulfil all the criteria, as they have a hierarchical porous structure similar to that of trabecular bone, they can bond to bone and soft tissue and they release silicon and calcium ions that have been found to up-regulate seven families of genes in osteogenic cells. Their hierarchical structure can be tailored for the required rate of tissue bonding, resorption and delivery of dissolution products. This paper describes how the structure and properties of the scaffolds are being optimized with respect to cell response and that tissue culture techniques must be optimized to enable growth of new bone in vitro .

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nicole Kleger ◽  
Clara Minas ◽  
Patrick Bosshard ◽  
Iacopo Mattich ◽  
Kunal Masania ◽  
...  

AbstractPorous materials are relevant for a broad range of technologies from catalysis and filtration, to tissue engineering and lightweight structures. Controlling the porosity of these materials over multiple length scales often leads to enticing new functionalities and higher efficiency but has been limited by manufacturing challenges and the poor understanding of the properties of hierarchical structures. Here, we report an experimental platform for the design and manufacturing of hierarchical porous materials via the stereolithographic printing of stable photo-curable Pickering emulsions. In the printing process, the micron-sized droplets of the emulsified resins work as soft templates for the incorporation of microscale porosity within sequentially photo-polymerized layers. The light patterns used to polymerize each layer on the building stage further generate controlled pores with bespoke three-dimensional geometries at the millimetre scale. Using this combined fabrication approach, we create architectured lattices with mechanical properties tuneable over several orders of magnitude and large complex-shaped inorganic objects with unprecedented porous designs.


2018 ◽  
Vol 7 (3) ◽  
pp. 181-190
Author(s):  
Parisa Pooyan ◽  
Luke P. Brewster ◽  
Rina Tannenbaum ◽  
Hamid Garmestani

Abstract As a rapidly growing area in materials design, the biomimetic approach at the frontier between biology and materials science aims to introduce advanced materials with structural diversities and functional versatilities by mimicking remarkable systems available in nature. Inspired by the fascinating nanostructured assembly existing in the cell walls of different plant species, we designed two fully bio-based green nanomaterials reinforced with renewable polysaccharide nanoparticles in the form of cellulose nanowhiskers (CNWs). In our initial design, the CNWs were incorporated into a cellulose acetate propionate matrix to form a bionanocomposite film, while in the second design the CNWs were entangled within a network of a collagenous medium to introduce a bionanocomposite hydrogel. Tensile and rheological measurements were carried out to study the system’s deformation as subjected to axial force or oscillatory shear. Biocompatibility was tested via incubation of human bone marrow-derived mesenchymal stem cells in vitro. Careful control of the processing conditions resulted in a three-dimensional rigid CNW network percolating within both biopolymer matrices, giving rise to an excellent performance at only a small fraction of CNWs at 3 wt.%. This study reveals that the fully bio-based green nanomaterials with enhanced mechanical percolation could construct a suitable platform for scaffolding in tissue engineering.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2006
Author(s):  
Markus Merk ◽  
Orlando Chirikian ◽  
Christian Adlhart

Recent advancements in tissue engineering and material science have radically improved in vitro culturing platforms to more accurately replicate human tissue. However, the transition to clinical relevance has been slow in part due to the lack of biologically compatible/relevant materials. In the present study, we marry the commonly used two-dimensional (2D) technique of electrospinning and a self-assembly process to construct easily reproducible, highly porous, three-dimensional (3D) nanofiber scaffolds for various tissue engineering applications. Specimens from biologically relevant polymers polycaprolactone (PCL) and gelatin were chemically cross-linked using the naturally occurring cross-linker genipin. Potential cytotoxic effects of the scaffolds were analyzed by culturing human dermal fibroblasts (HDF) up to 23 days. The 3D PCL/gelatin/genipin scaffolds produced here resemble the complex nanofibrous architecture found in naturally occurring extracellular matrix (ECM) and exhibit physiologically relevant mechanical properties as well as excellent cell cytocompatibility. Samples cross-linked with 0.5% genipin demonstrated the highest metabolic activity and proliferation rates for HDF. Scanning electron microscopy (SEM) images indicated excellent cell adhesion and the characteristic morphological features of fibroblasts in all tested samples. The three-dimensional (3D) PCL/gelatin/genipin scaffolds produced here show great potential for various 3D tissue-engineering applications such as ex vivo cell culturing platforms, wound healing, or tissue replacement.


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7684
Author(s):  
Thanapon Muenwacha ◽  
Oratai Weeranantanapan ◽  
Nuannoi Chudapongse ◽  
Francisco Javier Diaz Sanchez ◽  
Santi Maensiri ◽  
...  

A high piezoelectric coefficient polymer and biomaterial for bone tissue engineering— poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)—has been successfully fabricated into 3D scaffolds using the wet electrospinning method. Three-dimensional (3D) scaffolds have significant advantages for tissue engineering applications. Electrospinning is an advanced method and can fabricate 3D scaffolds. However, it has some limitations and is difficult to fabricate nanofibers into 3D shapes because of the low controllability of porosity and internal pore shape. The PVDF-HFP powders were dissolved in a mixture of acetone and dimethylformamide with a ratio of 1:1 at various concentrations of 10, 13, 15, 17, and 20 wt%. However, only the solutions at 15 and 17 wt% with optimized electrospinning parameters can be fabricated into biomimetic 3D shapes. The produced PVDF-HFP 3D scaffolds are in the cm size range and mimic the structure of the natural nests of termites of the genus Apicotermes. In addition, the 3D nanofiber-based structure can also generate more electrical signals than the conventional 2D ones, as the third dimension provides more compression. The cell interaction with the 3D nanofibers scaffold was investigated. The in vitro results demonstrated that the NIH 3T3 cells could attach and migrate in the 3D structures. While conventional electrospinning yields 2D (flat) structures, our bio-inspired electrospun termite nest-like 3D scaffolds are better suited for tissue engineering applications since they can potentially mimic native tissues as they have biomimetic structure, piezoelectric, and biological properties.


2018 ◽  
Vol 65 (1) ◽  
pp. 37-44
Author(s):  
Dijana Trišić ◽  
Vukoman Jokanović ◽  
Đorđe Antonijević ◽  
Dejan Marković

Summary Stem cells have shown great potential for in vitro tissue engineering, regenerative medicine, cell therapy and pharmaceutical applications. All these applications, especially in clinical trials, will require guided production of high-quality cells. Traditional culture techniques and applications have been performed for the majority of primary and established cell lines and standardized for various analyses. Still, these culture conditions are unable to mimic dynamic and specialized three-dimensional microenvironment of the stem cells’ niche from in vivo conditions. In an attempt to provide biomimetic microenvironments for stem cells in vitro growth, three-dimensional culture techniques have been developed. In our study advantages of newly developed porous scaffolds as the most promising in vitro imitation of niche that provides physical support, enables cell growth, regeneration and neovascularization, while they are replaced in time with newly created tissue was explained. Furthermore, dynamic cultivation techniques have been described, as new way of cell culturing that will be the main subject of our future research. In that manner, by developing an optimal dynamic culturing method, high-quality new cells and tissues would be possible to obtain, for any future clinical application.


2021 ◽  
Vol 12 (3) ◽  
pp. 45
Author(s):  
Yasaman Delkash ◽  
Maxence Gouin ◽  
Tanguy Rimbeault ◽  
Fatemeh Mohabatpour ◽  
Petros Papagerakis ◽  
...  

Three-dimensional (3D) bioprinting is an emerging fabrication technique to create 3D constructs with living cells. Notably, bioprinting bioinks are limited due to the mechanical weakness of natural biomaterials and the low bioactivity of synthetic peers. This paper presents the development of a natural bioink from chicken eggwhite and sodium alginate for bioprinting cell-laden patches to be used in endothelialized tissue engineering applications. Eggwhite was utilized for enhanced biological properties, while sodium alginate was used to improve bioink printability. The rheological properties of bioinks with varying amounts of sodium alginate were examined with the results illustrating that 2.0–3.0% (w/v) sodium alginate was suitable for printing patch constructs. The printed patches were then characterized mechanically and biologically, and the results showed that the printed patches exhibited elastic moduli close to that of natural heart tissue (20–27 kPa) and more than 94% of the vascular endothelial cells survived in the examination period of one week post 3D bioprinting. Our research also illustrated the printed patches appropriate water uptake ability (>1800%).


Author(s):  
Eamon J. Sheehy ◽  
Tatiana Vinardell ◽  
Conor T. Buckley ◽  
Daniel J. Kelly

Tissue engineering applications aim to replace or regenerate damaged tissues through a combination of cells, three-dimensional scaffolds, and signaling molecules [1]. The endochondral approach to bone tissue engineering [2], which involves remodeling of an intermittent hypertrophic cartilaginous template, may be superior to the traditional intramembranous approach. Naturally derived hydrogels have been used extensively in tissue engineering applications [3]. Mesenchymal stem cell (MSC) seeded hydrogels may be a particularly powerful tool in scaling-up engineered endochondral bone grafts as the low oxygen conditions that develop within large constructs enhance in vitro chondrogenic differentiation and functional development [4]. A key requirement however, is that the hydrogel must allow for remodeling of the engineered hypertrophic cartilage into bone and also facilitate vascularization of the graft. The first objective of this study was to compare the capacity of different naturally derived hydrogels (alginate, chitosan, and fibrin) to generate in vivo endochondral bone. The secondary objective was to investigate the possibility of engineering a ‘scaled-up’ anatomically accurate distal phalange as a paradigm for whole bone tissue engineering.


Sign in / Sign up

Export Citation Format

Share Document