Low Osmolality Medium for Naïve iPS Cell Maintenance
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Solution Overview
Problem
Current methods for maintaining and expanding human induced pluripotent stem cells (iPS cells) face challenges in preserving their pluripotent state and efficiency of genetic modifications, particularly in maintaining a naïve state and efficient dissociation for targeted genetic modifications.
Innovation Solution
A low osmolality medium comprising leukemia inhibitory factor (LIF), a glycogen synthase kinase 3 (GSK3) inhibitor, and a MEK inhibitor is used to culture iPS cells, allowing for the enrichment and maintenance of naïve or naïve-like iPS cells, enabling efficient enzymatic dissociation and genetic modifications without the need for ROCK inhibitors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional high osmolality medium is used to culture iPS cells, then cell growth and maintenance are supported, but the cells become committed for lineage specification and lose naïve pluripotent state
Solution Approach 1:
The patent applies parameter changes by reducing the osmolality of the culture medium from conventional high levels to specifically 175-280 mOsm/kg. This parameter change in medium osmolality, combined with specific cytokine concentrations (LIF at 10-1000 U/mL), transforms the culture conditions to maintain naïve pluripotent state and prevent lineage commitment
2Reliability
If ROCK inhibitors are used to maintain iPS cells, then cell survival is improved, but enzymatic dissociation efficiency decreases
Solution Approach 1:
The patent applies preliminary action by removing ROCK inhibitors from the culture medium before enzymatic dissociation is performed. This preliminary removal of the inhibitor enables efficient enzymatic dissociation into single-cell suspensions, while cell survival is maintained through the optimized low osmolality medium formulation with LIF and kinase inhibitors
Solution Approach 2:
The patent applies the taking out principle by extracting ROCK inhibitors from the culture medium formulation. This removal allows enzymatic dissociation to proceed efficiently without inhibition, while cell survival is supported by the alternative medium composition containing LIF and specific kinase inhibitors
3Adaptability or versatility
If primed state iPS cells are used, then lineage specification is enabled, but pluripotency level decreases compared to naïve state
Solution Approach 1:
The patent applies dynamics by enabling reversible transitions between naïve and primed states through controlled manipulation of culture conditions. The low osmolality medium with LIF and kinase inhibitors maintains naïve state, while the dynamic nature of the system allows differentiation into primed state when needed, providing flexibility in pluripotency level control
Data Source
AI summary
Methods and compositions are provided for generating or maintaining human iPS cells in culture. Methods include the use of a low osmolality medium to make human iPS cells, or use of a low osmolality medium to maintain human iPS cells. Methods for making targeted genetic modification to human iPS cells cultured in low osmolality medium are also included. Compositions include human iPS cells cultured and maintained using the low osmolality medium defined herein.