Cryopreserved Transiently Transfected Cells for Reliable Drug Screening

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Solution Overview

Problem

Current methods for screening drug candidates are time-consuming and resource-intensive due to the variability of recombinant protein expression in stable cell lines and the limited shelf life and viability issues of freshly plated cells, which can lead to unreliable experimental results.

Innovation Solution

A process involving transient transfection of cells with genes encoding drug transporter proteins like OAT1/Oat1 via electroporation, followed by cryopreservation within 48 hours, to maintain detectable protein activity post-thaw, using cell lines such as HEK293, CHO, and MDCK cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If stable cell lines are used for drug screening, then consistent protein expression can be achieved, but significant time and resources are required to generate and maintain frozen stocks, and protein expression level becomes variable over time

Engineering Contradiction:

Improveprotein expression consistencyVSAvoidtime to generate and maintain cell lines

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent employs transiently transfected cells that are cryopreserved and used for a limited period (up to 6 months) rather than maintaining stable cell lines indefinitely. These cells are discarded after use and replaced with fresh batches, eliminating the need for long-term maintenance of stable cell lines while avoiding the time-consuming process of generating new stable lines for each experiment.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent performs transfection and cryopreservation of cells in advance, preparing batches of transiently transfected cells that can be stored and used later. This preliminary preparation allows researchers to have ready-to-use cells with consistent protein expression without needing to generate stable cell lines beforehand, reducing both time and resource investment.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If freshly plated cells are used for screening, then cell viability is high, but shelf life is limited to a few days and shipping is difficult

Engineering Contradiction:

Improvecell viabilityVSAvoidshelf life of cells

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent utilizes cryopreservation to transition cells from a living, metabolically active state to a frozen, metabolically dormant state. This phase transition allows cells to be stored for extended periods (up to 6 months) while maintaining viability, and can be easily shipped in frozen condition. When needed, cells are thawed and return to their active state for screening assays.

Inventive Principle:

Principle #36Phase transitions

3Stability of the object's composition

If stable cell lines are generated, then permanent modification of host genome occurs, but this leads to abnormal expression of other genes and unreliable experimental results

Engineering Contradiction:

Improvegenetic stabilityVSAvoidexperimental result reliability

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The patent extracts the foreign gene from the host genome by using transient transfection instead of stable integration. The plasmid DNA is introduced into cells temporarily, allowing protein expression without permanent genetic modification. This extraction of the gene from the genomic context eliminates the risk of insertional mutagenesis and unintended effects on host gene expression, ensuring more reliable experimental results.

Inventive Principle:

Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method provides stable and reliable drug transporter protein activity in recombinant cells for extended periods post-thaw, reducing the time and resource requirements for drug development while ensuring consistent experimental results.

Implementation Method 1

transiently transfecting cells by electroporation with one or more genes encoding OAT1/Oat1

Methodology Applied

Scientific EffectElectroporation:

Implementation Method 2

cryopreserving the transiently transfected recombinant cells within 48 hrs of transfection

Methodology Applied

Scientific EffectCryopreservation: Cryogenics

Data Source

PatentEP3736329B1Consumable cryopreserved cells transiently overexpressing gene(s) encoding drug transporter protein(s) and/or drug metabolizing enzyme(s)

Publication Date: 2022.03.30 DISCOVERY LIFE SCI LLC

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AI summary

The present invention discloses cryopreserved recombinant cells for screening drug candidates that transiently overexpress one or more drug transporter proteins and/or drug metabolizing enzymes. Advantageously, such cells provide a cost-efficient consumable product that streamlines the process of screening whether drug candidates are substrates or inhibitors of drug transporter proteins and/or drug metabolizing enzymes.