3D Bioprinting of Tissue/Organ Models Pati, Falguni; Gantelius, Jesper; Svahn, Helene Andersson
Angewandte Chemie (International ed.),
April 4, 2016, Volume:
55, Issue:
15
Journal Article
Peer reviewed
In vitro tissue/organ models are useful platforms that can facilitate systematic, repetitive, and quantitative investigations of drugs/chemicals. The primary objective when developing tissue/organ ...models is to reproduce physiologically relevant functions that typically require complex culture systems. Bioprinting offers exciting prospects for constructing 3D tissue/organ models, as it enables the reproducible, automated production of complex living tissues. Bioprinted tissues/organs may prove useful for screening novel compounds or predicting toxicity, as the spatial and chemical complexity inherent to native tissues/organs can be recreated. In this Review, we highlight the importance of developing 3D in vitro tissue/organ models by 3D bioprinting techniques, characterization of these models for evaluating their resemblance to native tissue, and their application in the prioritization of lead candidates, toxicity testing, and as disease/tumor models.
Looking at the fine print: 3D bioprinting offers exciting prospects for printing 3D tissue/organ models. This technique can recreate the spatial and chemical complexity inherent to native tissues and organs. Hence, bioprinted tissues/organs have the potential to be useful in the prioritization of lead candidates, toxicity testing, and as disease/tumor models.
Collagen is the most abundant protein found in animal body and widely used for biomedical and pharmaceutical applications. However, its applicability is severely limited due to high cost. Fish ...processing waste, which otherwise cause serious environmental pollution, is a promising cost effective collagen source. In the present study, collagen was isolated from scales of
Labeo rohita (Rohu) and
Catla catla (Catla). It is first time that these species are used as sources of collagen. Thermo-gravimetric analysis (TGA) revealed maximum demineralization achieved after 48
h of EDTA treatment of intact scale. The isolated protein was confirmed as collagen by different physico-chemical techniques like FTIR, SDS–PAGE, and CD. Further amino acid analysis corroborates isolation of type I collagen. A major characteristic of obtained collagen was found to have denaturation temperature (
T
d) of 36.5
°C, which is promising as an advantage for biomedical application due to closeness in
T
d to mammalian collagen.
Abstract Engineered adipose tissue constructs that are capable of reconstructing soft tissue with adequate volume would be worthwhile in plastic and reconstructive surgery. Tissue printing offers the ...possibility of fabricating anatomically relevant tissue constructs by delivering suitable matrix materials and living cells. Here, we devise a biomimetic approach for printing adipose tissue constructs employing decellularized adipose tissue (DAT) matrix bioink encapsulating human adipose tissue-derived mesenchymal stem cells (hASCs). We designed and printed precisely-defined and flexible dome-shaped structures with engineered porosity using DAT bioink that facilitated high cell viability over 2 weeks and induced expression of standard adipogenic genes without any supplemented adipogenic factors. The printed DAT constructs expressed adipogenic genes more intensely than did non-printed DAT gel. To evaluate the efficacy of our printed tissue constructs for adipose tissue regeneration, we implanted them subcutaneously in mice. The constructs did not induce chronic inflammation or cytotoxicity postimplantation, but supported positive tissue infiltration, constructive tissue remodeling, and adipose tissue formation. This study demonstrates that direct printing of spatially on-demand customized tissue analogs is a promising approach to soft tissue regeneration.
Direct-write assembly allows rapid fabrication of complex three-dimensional (3D) architectures, such as scaffolds simulating anatomical shapes, avoiding the need for expensive lithographic masks. ...However, proper selection of polymeric ink composition and tailor-made viscoelastic properties are critically important for smooth deposition of ink and shape retention. Deposition of only silk solution leads to frequent clogging due to shear-induced β-sheet crystallization, whereas optimized viscoelastic property of silk-gelatin blends facilitate the flow of these blends through microcapillary nozzles of varying diameter. This study demonstrates that induction of controlled changes in scaffold surface chemistry, by optimizing silk-gelatin ratio, can govern cell proliferation and maintenance of chondrocyte morphology. Microperiodic silk-gelatin scaffolds can influence postexpansion redifferentiation of goat chondrocytes by enhancing Sox-9 gene expression, aggregation, and driving cartilage matrix production, as evidenced by upregulation of collagen type II and aggrecan expression. The strategy for optimizing redifferentiation of chondrocytes can offer valuable consideration in scaffold-based cartilage repair strategies.
Several studies have focused on the regeneration of liver tissue in a two-dimensional (2D) planar environment, whereas actual liver tissue is three-dimensional (3D). Cell printing technology has been ...successfully utilized for building 3D structures; however, the poor mechanical properties of cell-laden hydrogels are a major concern. Here, we demonstrate the printing of a 3D cell-laden construct and its application to liver tissue engineering using 3D cell printing technology through a multi-head tissue/organ building system. Polycaprolactone (PCL) was used as a framework material because of its excellent mechanical properties. Collagen bioink containing three different types of cells-hepatocytes (HCs), human umbilical vein endothelial cells , and human lung fibroblasts--was infused into the canals of a PCL framework to induce the formation of capillary--like networks and liver cell growth. A co-cultured 3D microenvironment of the three types of cells was successfully established and maintained. The vascular formation and functional abilities of HCs (i.e., albumin secretion and urea synthesis) demonstrated that the heterotypic interaction among HCs and nonparenchymal cells increased the survivability and functionality of HCs within the collagen gel. Therefore, our results demonstrate the prospect of using cell printing technology for the creation of heterotypic cellular interaction within a structure for liver tissue engineering.
Bioprinting is an acclaimed technique that allows the scaling of 3D architectures in an organized pattern but suffers from a scarcity of appropriate bioinks. Decellularized extracellular matrix ...(dECM) from xenogeneic species has garnered support as a biomaterial to promote tissue-specific regeneration and repair. The prospect of developing dECM-based 3D artificial tissue is impeded by its inherent low mechanical properties. In recent years, 3D bioprinting of dECM-based bioinks modified with additional scaffolds has advanced the development of load-bearing constructs. However, previous attempts using dECM were limited to low-temperature bioprinting, which is not favorable for a longer print duration with cells. Here, we report the development of a multi-material decellularized liver matrix (dLM) bioink reinforced with gelatin and polyethylene glycol to improve rheology, extrudability, and mechanical stability. This shear-thinning bioink facilitated extrusion-based bioprinting at 37 °C with HepG2 cells into a 3D grid structure with a further enhancement for long-term applications by enzymatic crosslinking with mushroom tyrosinase. The heavily crosslinked structure showed a 16-fold increase in viscosity (2.73 Pa s−1) and a 32-fold increase in storage modulus from the non-crosslinked dLM while retaining high cell viability (85–93%) and liver-specific functions. Our results show that the cytocompatible crosslinking of dLM bioink at physiological temperatures has promising applications for extended 3D-printing procedures.
Definitive treatment of dry eye disease (DED), one of the commonest ocular surface disorders, has remained elusive despite several recent advances in better diagnostics and the introduction of newer ...therapeutic molecules. The current treatment paradigms rely heavily on lubricating eye drops and anti-inflammatory agents that may need to be used long-term and are mainly palliative. Research is ongoing not only for a curative treatment option but also to improve the potency and efficacy of existing drug molecules through better formulations and delivery platforms. In the past two decades, significant advancement has been made in terms of preservative-free formulations, biomaterials such as nanosystems and hydrogels, stem cell therapy, and creation of a bioengineered lacrimal gland. This review comprehensively summarizes the newer approaches to DED treatment, which are biomaterials such as nanosystems, hydrogels, and contact lenses for drug delivery, cell and tissue-based regenerative therapy for damaged lacrimal gland and ocular surface, and tissue engineering for developing artificial lacrimal gland. Also, their potential efficacies in animal models or in vitro studies and possible limitations are discussed. The ongoing research looks promising and needs to be supported with clinical efficacy and safety studies for human use.
The liver exhibits complex geometrical morphologies of hepatic cells arranged in a hexagonal lobule with an extracellular matrix (ECM) organized in a specific pattern on a multi-scale level. Previous ...studies have utilized 3D bioprinting and microfluidic perfusion systems with various biomaterials to develop lobule-like constructs. However, they all lack anatomical relevance with weak control over the size and shape of the fabricated structures. Moreover, most biomaterials lack liver-specific ECM components partially or entirely, which might limit their biomimetic mechanical properties and biological functions. Here, we report 3D bioprinting of a sacrificial PVA framework to impart its trilobular hepatic structure to the decellularized liver extracellular matrix (dLM) hydrogel with polyethylene glycol-based crosslinker and tyrosinase to fabricate a robust multi-scale 3D liver construct. The 3D trilobular construct exhibits higher crosslinking, viscosity (182.7 ± 1.6 Pa·s), and storage modulus (2554 ± 82.1 Pa) than non-crosslinked dLM. The co-culture of HepG2 liver cells and NIH 3T3 fibroblast cells exhibited the influence of fibroblasts on liver-specific activity over time (7 days) to show higher viability (90–91.5%), albumin secretion, and increasing activity of four liver-specific genes as compared to the HepG2 monoculture. This technique offers high lumen patency for the perfusion of media to fabricate a densely populated scaled-up liver model, which can also be extended to other tissue types with different biomaterials and multiple cells to support the creation of a large functional complex tissue.
The process of corneal wound healing is complex and induces scar formation. Corneal scarring is a leading cause of blindness worldwide. The fibrotic healing of a major ocular wound disrupts the ...highly organized fibrillar collagen arrangement of the corneal stroma, rendering it opaque. The process of regaining this organized extracellular matrix (ECM) arrangement of the stromal layer to restore corneal transparency is complicated. The surface retention capacity of ocular drugs is poor, and there is a large gap between suitable corneal donors and clinical requirements. Therefore, a more efficient way of treating corneal scarring is needed. The eight major classes of interventions targeted as therapeutic tools for healing scarred corneas include those based on exosomes, targeted gene therapy, microRNAs, recombinant viral vectors, histone deacetylase inhibitors, bioactive molecules, growth factors, and nanotechnology. This review highlights the recent advancements in molecular therapeutics to restore a cornea without scarring. It also provides a scope to overcome the limitations of present studies and perform robust clinical research using these strategies.
Biomaterials play a fundamental role in tissue engineering by providing biochemical and physical cues that influence cellular fate and matrix development. Decellularized extracellular matrix (dECM) ...as a biomaterial is distinguished by its abundant composition of matrix proteins, such as collagen, elastin, fibronectin, and laminin, as well as glycosaminoglycans and proteoglycans. However, the mechanical properties of only dECM-based constructs may not always meet tissue-specific requirements. Recent advancements address this challenge by utilizing hybrid biomaterials that harness the strengths of silk fibroin (SF), which contributes the necessary mechanical properties, while dECM provides essential cellular cues for in vitro studies and tissue regeneration. This review discusses emerging trends in developing such biopolymer blends, aiming to synergistically combine the advantages of SF and dECM through optimal concentrations and desired cross-linking density. We focus on different fabrication techniques and cross-linking methods that have been utilized to fabricate various tissue-engineered hybrid constructs. Furthermore, we survey recent applications of such biomaterials for the regeneration of various tissues, including bone, cartilage, trachea, bladder, vascular graft, heart, skin, liver, and other soft tissues. Finally, the trajectory and prospects of the constructs derived from this blend in the tissue engineering field have been summarized, highlighting their potential for clinical translation.
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•Brief outlook on dECM and SF and transition to their biopolymeric hybrids for tissue engineering and regenerative medicine.•Overview of hybrid scaffolding fabrication strategies, crosslinking methods, and biological performance.•Recent applications in various tissue engineering approaches promoting cell-tissue interaction and regeneration.•Significance in biomaterials research with potential clinical translation.
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