Review: bioreactor design towards generation of relevant engineered tissues: focus on clinical translation

Liver cells cultured in 3D bioreactors is an interesting option for temporary extracorporeal liver support in the treatment of acute liver failure and for animal models for preclinical drug screening. Bioreactor capacity to eliminate drugs is generally used for assessing cell metabolic competence in different bioreactors or to scale-up bioreactor design and performance for clinical or preclinical applications. However, drug adsorption and physical transport often disguise the intrinsic drug biotransformation kinetics and cell metabolic state. In this study, we characterized the intrinsic kinetics of lidocaine elimination and adsorption by porcine liver cells cultured in 3D four-compartment hollow fiber membrane network perfusion bioreactors. Models of lidocaine transport and biotransformation were used to extract intrinsic kinetic information from response to lidocaine bolus of bioreactor versus adhesion cultures. Different from 2D adhesion cultures, cells in the bioreactors are organized in liver-like aggregates. Adsorption on bioreactor constituents significantly affected lidocaine elimination and was effectively accounted for in kinetic analysis. Lidocaine elimination and cellular monoethylglicinexylidide biotransformation featured first-order kinetics with near-to-in vivo cell-specific capacity that was retained for times suitable for clinical assist and drug screening. Different from 2D cultures, cells in the 3D bioreactors challenged with lidocaine were exposed to close-to-physiological lidocaine and monoethylglicinexylidide concentration profiles. Kinetic analysis suggests bioreactor technology feasibility for preclinical drug screening and patient assist and that drug adsorption should be accounted for to assess cell state in different cultures and when laboratory bioreactor design and performance is scaled-up to clinical use or toxicological drug screening.

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Long-Term Severe In Vitro Hypoxia Exposure Enhances the Vascularization Potential of Human Adipose Tissue-Derived Stromal Vascular Fraction Cell Engineered Tissues

International Journal of Molecular Sciences ◽

10.3390/ijms22157920 ◽

2021 ◽

Vol 22 (15) ◽

pp. 7920

Author(s):

Myroslava Mytsyk ◽

Giulia Cerino ◽

Gregory Reid ◽

Laia Gili Sole ◽

Friedrich S. Eckstein ◽

...

Keyword(s):

Adipose Tissue ◽

Therapeutic Potential ◽

Stromal Vascular Fraction ◽

Human Adipose Tissue ◽

Bioreactor Culture ◽

Proliferating Cells ◽

Angiogenic Potential ◽

Engineered Tissues

The therapeutic potential of mesenchymal stromal/stem cells (MSC) for treating cardiac ischemia strongly depends on their paracrine-mediated effects and their engraftment capacity in a hostile environment such as the infarcted myocardium. Adipose tissue-derived stromal vascular fraction (SVF) cells are a mixed population composed mainly of MSC and vascular cells, well known for their high angiogenic potential. A previous study showed that the angiogenic potential of SVF cells was further increased following their in vitro organization in an engineered tissue (patch) after perfusion-based bioreactor culture. This study aimed to investigate the possible changes in the cellular SVF composition, in vivo angiogenic potential, as well as engraftment capability upon in vitro culture in harsh hypoxia conditions. This mimics the possible delayed vascularization of the patch upon implantation in a low perfused myocardium. To this purpose, human SVF cells were seeded on a collagen sponge, cultured for 5 days in a perfusion-based bioreactor under normoxia or hypoxia (21% and <1% of oxygen tension, respectively) and subcutaneously implanted in nude rats for 3 and 28 days. Compared to ambient condition culture, hypoxic tension did not alter the SVF composition in vitro, showing similar numbers of MSC as well as endothelial and mural cells. Nevertheless, in vitro hypoxic culture significantly increased the release of vascular endothelial growth factor (p < 0.001) and the number of proliferating cells (p < 0.00001). Moreover, compared to ambient oxygen culture, exposure to hypoxia significantly enhanced the vessel length density in the engineered tissues following 28 days of implantation. The number of human cells and human proliferating cells in hypoxia-cultured constructs was also significantly increased after 3 and 28 days in vivo, compared to normoxia. These findings show that a possible in vivo delay in oxygen supply might not impair the vascularization potential of SVF- patches, which qualifies them for evaluation in a myocardial ischemia model.

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Progress of clinical translation of handheld and semi-handheld photoacoustic imaging

Photoacoustics ◽

10.1016/j.pacs.2021.100264 ◽

2021 ◽

Vol 22 ◽

pp. 100264

Author(s):

Qian Chen ◽

Wei Qin ◽

Weizhi Qi ◽

Lei Xi

Keyword(s):

Photoacoustic Imaging ◽

Clinical Translation

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Cell Therapy for Stroke: A Mechanistic Analysis

Neurosurgery ◽

10.1093/neuros/nyaa531 ◽

2020 ◽

Author(s):

Ben Jiahe Gu ◽

David K Kung ◽

Han-Chiao Isaac Chen

Keyword(s):

Stem Cells ◽

Clinical Trials ◽

Cell Therapy ◽

Clinical Translation ◽

Stroke Survivors ◽

Cell Replacement ◽

Preclinical Data ◽

Promising Strategy ◽

Mechanistic Analysis

Abstract Cell therapy has been widely recognized as a promising strategy to enhance recovery in stroke survivors. However, despite an abundance of encouraging preclinical data, successful clinical translation remains elusive. As the field continues to advance, it is important to reexamine prior clinical trials in the context of their intended mechanisms, as this can inform future preclinical and translational efforts. In the present work, we review the major clinical trials of cell therapy for stroke and highlight a mechanistic shift between the earliest studies, which aimed to replace dead and damaged neurons, and later ones that focused on exploiting the various neuromodulatory effects afforded by stem cells. We discuss why both mechanisms are worth pursuing and emphasize the means through which cell replacement can still be achieved.

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Exploitation of Marine-Derived Robust Biological Molecules to Manage Inflammatory Bowel Disease

Marine Drugs ◽

10.3390/md19040196 ◽

2021 ◽

Vol 19 (4) ◽

pp. 196

Author(s):

Muhammad Bilal ◽

Leonardo Vieira Nunes ◽

Marco Thúlio Saviatto Duarte ◽

Luiz Fernando Romanholo Ferreira ◽

Renato Nery Soriano ◽

...

Keyword(s):

Inflammatory Bowel Disease ◽

Bioactive Compounds ◽

Bowel Disease ◽

Clinical Translation ◽

Biologically Active ◽

Naturally Occurring ◽

Inflammatory Bowel ◽

Functional Features ◽

Biological Entities ◽

The Impact

Naturally occurring biological entities with extractable and tunable structural and functional characteristics, along with therapeutic attributes, are of supreme interest for strengthening the twenty-first-century biomedical settings. Irrespective of ongoing technological and clinical advancement, traditional medicinal practices to address and manage inflammatory bowel disease (IBD) are inefficient and the effect of the administered therapeutic cues is limited. The reasonable immune response or invasion should also be circumvented for successful clinical translation of engineered cues as highly efficient and robust bioactive entities. In this context, research is underway worldwide, and researchers have redirected or regained their interests in valorizing the naturally occurring biological entities/resources, for example, algal biome so-called “treasure of untouched or underexploited sources”. Algal biome from the marine environment is an immense source of excellence that has also been demonstrated as a source of bioactive compounds with unique chemical, structural, and functional features. Moreover, the molecular modeling and synthesis of new drugs based on marine-derived therapeutic and biological cues can show greater efficacy and specificity for the therapeutics. Herein, an effort has been made to cover the existing literature gap on the exploitation of naturally occurring biological entities/resources to address and efficiently manage IBD. Following a brief background study, a focus was given to design characteristics, performance evaluation of engineered cues, and point-of-care IBD therapeutics of diverse bioactive compounds from the algal biome. Noteworthy potentialities of marine-derived biologically active compounds have also been spotlighted to underlying the impact role of bio-active elements with the related pathways. The current review is also focused on the applied standpoint and clinical translation of marine-derived bioactive compounds. Furthermore, a detailed overview of clinical applications and future perspectives are also given in this review.

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Emerging biogenesis technologies of extracellular vesicles for tissue regenerative therapeutics

Journal of Tissue Engineering ◽

10.1177/20417314211019015 ◽

2021 ◽

Vol 12 ◽

pp. 204173142110190

Author(s):

Jung-Hwan Lee ◽

Ji-Young Yoon ◽

Jun Hee Lee ◽

Hae-Hyoung Lee ◽

Jonathan C Knowles ◽

...

Keyword(s):

Extracellular Vesicles ◽

Chemical Treatment ◽

Mass Production ◽

Disease Status ◽

Clinical Translation ◽

Technological Advances ◽

Tissue Healing ◽

Bio Imaging ◽

Key Issues ◽

Treatment Application

Extracellular vesicles (EVs), including exosomes, carry the genetic packages of RNA, DNA, and proteins and are heavily involved in cell-cell communications and intracellular signalings. Therefore, EVs are spotlighted as therapeutic mediators for the treatment of injured and dysfunctional tissues as well as biomarkers for the detection of disease status and progress. Several key issues in EVs, including payload content and bioactivity, targeting and bio-imaging ability, and mass-production, need to be improved to enable effective therapeutics and clinical translation. For this, significant efforts have been made recently, including genetic modification, biomolecular and chemical treatment, application of physical/mechanical cues, and 3D cultures. Here we communicate those recent technological advances made mainly in the biogenesis process of EVs or at post-collection stages, which ultimately aimed to improve the therapeutic efficacy in tissue healing and disease curing and the possibility of clinical translation. This communication will help tissue engineers and biomaterial scientists design and produce EVs optimally for tissue regenerative therapeutics.

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