Development of brain decellularized extracellular matrix bioink to recapitulate native microenvironment for 3D neural cell culture

In the field of neurodegenerative disease research, animal models, such as mice and rats, have enhanced the understanding of basic mechanism and neural disease progress [1]. However, the animal models have critical limitations that the animals are restrained to mimic pathophysiology of the human neural disease due to genetic difference and usually require a lot of cost and labor. Researchers in bioengineering have taken note of the culture of human-derived neural cells in vitro. Last a few decades, 2D plastic dish were used for culturing cells; however, neural cells on 2D environment has shown different characteristics to that of the 3D native environment. In this regards, researchers have focused on the neural cell culture in 3D hydrogel (e.g. Matrigel, type I collagen) to mimic the native environmental features [2]. Recently, decellularization of the neural tissue is emerging for recapitulating the native neural tissue environment [3]. Particularly, this strategy has a potential to preserve the component and composition of native extracellular matrix (ECM) which is comprised of sophisticated combination of growth factors, proteins, glycoproteins. In addition, reconstitution of decellularized extracellular matrix (dECM) can provide tissue-specific biophysical and biochemical cues to the cells. In this study, we developed a brain decellularized extracellular matrix (BdECM) and BdECM bioink for the human neural cell culture. Briefly, brain was isolated from a farm pig and we treated the tissue to multiple solutions with the physical agitation for decellularization process. After removing all cellular component from the porcine brain, the tissue was lyophilized and pulverized into the powder. The decellularization process was validated by quantifying residual DNA fraction (less than 5 w/w%) and GAG assay (approximately 102 w/w%). BdECM powder was solubilized in the weak acid to prepare BdECM bioink. 2 w/v % (20 mg/ml) BdECM bioink showed comparable biocompatibility to the porcine type 1 collagen hydrogel. We employed the human neural stem cells (HB1. F3) to evaluate its beneficial effects on proliferation and differentiation of neural stem cells. The human neural stem cells were encapsulated in 2 w/v % of BdECM bioink and 1 w/v % of type 1 collagen hydrogel that has similar stiffness to that of the 2 w/v % BdECM bioink. The neural stem cells in BdECM bioink showed significantly enhanced morphology of differentiated neuron, which were not expressed in the group of type I collagen hydrogel. The encapsulated neural stem cells in BdECM bioink expressed Tuj1 marker after 7 days culture and MAP2 marker after 14 days higher than that of type I collagen hydrogel. In this regard, BdECM bioink could be applied for 3D culture platform of various neural cell culture, such as neural progenitor cells, microglia, and astrocytes. We also expect BdECM bioink can provide a favorable effect for the neural tissue regeneration.1

Development of high-throughput drug screening platform that reproduces the gastric cancer-specific microenvironment using 3D Bioprinting technology

In recent years, in vitro anticancer drug toxicity evaluation and drug screening tests have been increasingly attempted for the development of new drugs under conditions that reproduce an environment similar to the human body through 3D cell culture. Also, various studies have been conducted in the development of patient-derived xenograft (PDX) for investigating the efficacy of anti-cancer drugs. However, they still have the critical limitations, we have established in vitro gastric cancer PDX culture conditions using porcine gastric tissue-derived decellularized extracellular matrix (gastric dECM) to overcome their limitation. Our system provide a microenvironment for PDX growth in vitro. This process can improve production efficiency, reduce the time and cost for sub-culturing PDX and achieve mass production for drug screening. Furthermore, we confirmed different drug resistance depending on the type of PDX. These in vitro PDX culture platform might be used for various cancer drug screening as well as evaluation method to validate rapid patient-specific drug response.2

Development of patient-specific glioblastoma model with 3D cell-printing technology

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Central nervous tissue-derived bioink offer an advantage in long-term cultivation of lower motor neurons for neuromuscular junction formation of 3D in vitro motor system

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A bioprinted human-glioblastoma-on-a-chip for the identification of patient-specific responses to chemoradiotherapy

Patient-specific ex vivo models of human tumours that recapitulate the pathological characteristics and complex ecology of native tumours could help determine the most appropriate cancer treatment for individual patients. Here, we show that bioprinted reconstituted glioblastoma tumours consisting of patient-derived tumour cells, vascular endothelial cells and decellularized extracellular matrix from brain tissue in a compartmentalized cancer-stroma concentric-ring structure that sustains a radial oxygen gradient, recapitulate the structural, biochemical and biophysical properties of the native tumours. We also show that the glioblastoma-on-a-chip reproduces clinically observed patient-specific resistances to treatment with concurrent chemoradiation and temozolomide, and that the model can be used to determine drug combinations associated with superior tumour killing. The patient-specific tumour-on-a-chip model might be useful for the identification of effective treatments for glioblastoma patients resistant to the standard first-line treatment.11Nsciescopu