3D cell culture
[3] Early studies in the 80's, led by Mina Bissell from the Lawrence Berkeley National Laboratory, highlighted the importance of 3D techniques for creating accurate in vitro culturing models.
[4] Eric Simon, in a 1988 NIH SBIR grant report, showed that electrospinning could be used to produce nano- and submicron-scale polystyrene and polycarbonate fibrous mats (now known as scaffolds) specifically intended for use as in vitro cell substrates.
[8][9][10][11][12][13][14][15][16] Standard 2D, or monolayer, cell cultures are inadequate representations of this environment, which often makes them unreliable predictors of in vivo drug efficacy and toxicity.
In a recent study potentiality of human CD34+ stem cells explored by generating in vitro agarose gel 3D model to understand the bone ossification process.
[26] The effectiveness of scaffolds in various applications, particularly in tissue engineering, is significantly impacted by factors such as pore distribution, exposed surface area, and porosity.
The quantity and arrangement of these elements influence both the depth and rate at which cells penetrate the scaffold volume, the structure of the resulting extracellular matrix, and ultimately, the success of the regenerative process.
The approach to crafting the optimal ECM replica relies on the specific characteristics of the culture in question and typically involves employing diverse and independent chemical processes.
However, a thoughtful integration of bioinspired cues into synthetic gels holds the potential to yield resilient and versatile scaffolds applicable across various cell culture systems.
[37] Other methods under investigation include the use of rotating wall vessel bioreactors, which spins and cultures the cells when they are constantly in free fall and forms aggregates in layers[44] Recently, some protocols have been standardized to produce uniform and reliable spheroids.
This approach allowed researchers to adjust the cell composition to attain the ideal conditions for promoting the synthesis of diverse angiogenic protein markers within the co-cultured clusteroids.
[52] The w/w Pickering emulsion template greatly aids in constructing 3D co-culture models, offering significant potential for applications in drug testing and tissue engineering.
The bioreactor uses bioactive synthetic materials such as polyethylene terephthalate membranes to surround the spheroid cells in an environment that maintains high levels of nutrients.
[15] Collaborative efforts between tissue engineering (TE) firms, academic institutions, and industrial partners can enhance the transformation of research-oriented bioreactors into efficient commercial manufacturing systems.
[57] Academic collaborators contribute foundational aspects, while industrial partners provide essential automation elements, ensuring compliance with regulatory standards and user-friendliness.
[58] Established consortia in Europe, such as REMEDI, AUTOBONE, and STEPS, focus on developing automated systems to streamline the engineering of autologous cell-based grafts.
[59] The aim is to meet regulatory criteria and ensure cost-effectiveness, making tissue-engineered products more clinically accessible and advancing the translational paradigm of TE from research to a competitive commercial field.
[60] The utilization of microfluidic technology facilitates the generation of intricate micro-scale structures and the precise manipulation of parameters, thereby emulating the in vivo cellular milieu.
The integration of microfluidic technology with 3D cell culture holds considerable potential for applications that seek to replicate in vivo tissue characteristics, notably exemplified by the evolving organ-on-a-chip system.
[64] One such challenge pertains to the difficulty in accessing cultured cells within microsystems, coupled with the intricate nature of sample extraction for subsequent assays.
[69] Two options that afford 1536-well formats are available from either Greiner Bio-One using the m3D Magnetic 3D bioprinting[70] and Corning Life Sciences which incorporates an ultra-low attachment surface coating, along with a microcavity geometry and gravity to create 3D models.
[80] The three-dimensional arrangement allows the cultures to provide a model that more accurately resembles human tissue in vivo without using animal test subjects.
[83] Innovative approaches to multiplexed cell-based assay designs, involving the selection of specific cell types, signaling pathways, and reporters, have become standard practice.
[86] The absence of a dependable translational assay toolkit for pharmacology and toxicology contributes to the high cost and inefficiency of transitioning from initial in vitro cell-based screens to in vivo testing and subsequent clinical approvals.
The distinctive advantages and challenges associated with these models are scrutinized, with a specific focus on their suitability for cell-based assays and their predictive capabilities, crucial for establishing accurate correlations with in vivo mechanisms of drug toxicity.
[91] While two-dimensional (2D) in-vitro cell culture models are commonly utilized and have contributed significantly to our understanding, they frequently exhibit limitations in faithfully replicating the natural structures of in-vivo tissues.
[94] The past decade has witnessed substantial endeavors aimed at advancing three-dimensional (3D) in-vitro cell culture models to better emulate in-vivo physiological conditions.
[95] Additionally, it explores the potential of 3D cell culture models to address the existing gaps in the current paradigm, offering a promising avenue for more accurate toxicity assessments.
