Three-dimensionally engineered biomimetic tissue models for in vitro drug evaluation: delivery, efficacy and toxicity.

INTRODUCTION: Three-dimensionally (3D) engineered biomimetic tissue models are sought after due to their high fidelity in mimicking various native tissues of the human body, this quality of which gives them an important role at the forefront of drug discovery and development. A multitude of studies have consistently indicated that gene expression profiles, cellular phenotypes, differentiation capabilities and functionalities are all affected by tissue architecture. Thus, the drug evaluation process will stand to gain immense benefits from the fairly accurate predictions of cellular responses displayed by 3D-engineered tissue models when exposed to the drugs of interest in vitro. Stemming from this fact, many studies have set out to capitalize on developing tissue models that are tailored to specific aspects of drug evaluation including the tests of novel drug delivery systems, drug efficacy and toxicity. AREAS COVERED: The areas covered include fabrication methods and usage of 3D in vitro tumor models in cancer research, focusing on the evaluation of delivery and efficacy of various anticancer drugs or other therapeutic agents. Also covered are the use of 3D in vitro inflammatory tissue models in anti-inflammation research, centering on osteoarthritis (OA) and rheumatoid arthritis (RA) and the use of 3D in vitro tissue models designed for drug toxicity evaluation specifically with liver-mimetic tissues. EXPERT OPINION: Currently available 3D tissue models in various fields of research have already displayed their capabilities in predicting cellular responses to various therapeutic agents and delivery methods with better accuracy than their 2D counterparts, albeit being in need of much refinement before they can be successfully applied for reliable drug evaluation. Given further development and improvement, it is highly probable that the 3D-engineered tissue models may perform as living platforms for dynamic drug evaluation in vitro.