**6. Conclusion**

In particular, a plethora of research studies have shed light on the fact that in spite of the availability of advanced organ-on-chip technologies and bioengineered 3D models, the application is limited by drug companies due to their relatively novel approach which is more likely requires to undergo further validation and characterization. Moreover, 3D cell culture models with high-throughput screening in combination with high-content leads to the identification of clinically relevant compounds. However, still many difficulties are being faced as 3D cell cultures do not meet certain criteria in the drug discovery process with regard to size, morphology, complexity, and protocol for assaying. It requires ample standardization and optimization to extract successful specific phenotypes for drug screening. Thus, there are few 3D models that are constrained for their restricted access due to limited permeability. Following the advances in protein therapeutics, more improvements in generating sophisticated therapeutic protein products will be developed for better futuristic research.
