Organ-on-a-Chip: Ubi sumus? Fundamentals and Design Aspects.

This review outlines the evolutionary journey from traditional two-dimensional (2D) cell culture to the revolutionary field of organ-on-a-chip technology. Organ-on-a-chip technology integrates microfluidic systems to mimic the complex physiological environments of human organs, surpassing the limitations of conventional 2D cultures. This evolution has opened new possibilities for understanding cell-cell interactions, cellular responses, drug screening, and disease modeling. However, the design and manufacture of microchips significantly influence their functionality, reliability, and applicability to different biomedical applications. Therefore, it is important to carefully consider design parameters, including the number of channels (single, double, or multi-channels), the channel shape, and the biological context. Simultaneously, the selection of appropriate materials compatible with the cells and fabrication methods optimize the chips' capabilities for specific applications, mitigating some disadvantages associated with these systems. Furthermore, the success of organ-on-a-chip platforms greatly depends on the careful selection and utilization of cell resources. Advances in stem cell technology and tissue engineering have contributed to the availability of diverse cell sources, facilitating the development of more accurate and reliable organ-on-a-chip models. In conclusion, a holistic perspective of in vitro cellular modeling is provided, highlighting the integration of microfluidic technology and meticulous chip design, which play a pivotal role in replicating organ-specific microenvironments. At the same time, the sensible use of cell resources ensures the fidelity and applicability of these innovative platforms in several biomedical applications.

Drug release from lipid liquid crystalline phases: relation with phase behavior.

INTRODUCTION: We studied the release of propranolol hydrochloride (PHCl), a water-soluble amphiphilic drug, from monoolein (MO)/water and phytantriol/water systems. METHODS: We related the dissolution profiles with phase behavior and viscosity of the different liquid crystalline phases. Diolein has been added aiming to stabilize the cubic phases and thus preventing formation of less viscous (lamellar) phases. RESULTS: Formulations display first-order release rates and diffusion release mechanism. Some formulations (mostly MO) were close to zero-order release in the first 120 minutes. DISCUSSION: Release mechanism can be influenced by phase changes during dissolution. CONCLUSIONS: Both MO and phytantriol show good potential to be used for propranolol hydrochloride sustained drug release.