Exosome Lyophilization Using Trehalose Buffer

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Solution Overview

Problem

Current methods for storing exosomes, such as freezing, limit their shelf life and therapeutic potency, as they require cold temperatures and do not preserve the structural and biochemical integrity of these extracellular vesicles for long-term use at ambient temperatures.

Innovation Solution

A method involving lyophilization of exosomes using a buffer with trehalose at a concentration of 4% w/v, followed by freezing and freeze-drying, which maintains at least one biological activity of the exosomes, including CD73 enzymatic activity and cardioprotective potency, even when stored at ambient temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If exosomes are stored frozen at -20°C or -80°C, then their shelf life is extended to at most one year, but they require cold temperatures and their accessibility is limited

Engineering Contradiction:
Improveshelf lifeVSAvoidstorage temperature
Core Design Contradiction:
Duration of action of stationary objectVSTemperature

Solution Approach 1:

The patent changes the storage temperature parameter from frozen conditions (-20°C or -80°C) to ambient temperature (20-25°C) by modifying the exosome formulation with stabilizing agents such as sugars (sucrose, trehalose), polyols (glycerol, sorbitol), and proteins (albumin, gelatin), enabling long-term storage without cold chain requirements

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces stabilizing agents (sugars, polyols, proteins) as intermediary substances that mediate between the exosomes and the ambient temperature environment, protecting the exosomes from thermal damage and maintaining their structural and functional integrity during storage at room temperature

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If exosomes are lyophilised in phosphate buffered saline with sucrose, then they can be stored at 4°C for up to a year without losing proteins or affecting particle size, but the effect on protein activity or therapeutic potency was not preserved

Engineering Contradiction:
Improvestructural and biochemical integrityVSAvoidtherapeutic potency
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent uses composite stabilization systems combining multiple agents (sugars like sucrose and trehalose, polyols like glycerol and sorbitol, and proteins like albumin and gelatin) that work synergistically to preserve both the structural integrity and therapeutic potency of exosomes during lyophilization and storage

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes the concentration parameters of stabilizing agents in the lyophilization formulation, using specific ranges (e.g., 5-20% w/v sugars, 1-10% v/v polyols, 0.1-5% w/v proteins) to ensure both structural stability and retention of biological activity after reconstitution

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If conventional lyophilization methods are used, then water is removed from the frozen suspension, but protein structure conservation does not always translate into protein activity conservation

Engineering Contradiction:
Improveprotein structureVSAvoidprotein activity
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent introduces protective agents (sugars, polyols, proteins) as intermediaries that form protective matrices around exosome proteins during freezing and drying, preventing denaturation and maintaining both structural integrity and biological activity through the lyophilization process

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies stabilizing agents before the lyophilization process to cushion and protect the exosomes from the harsh conditions of freezing and drying, preventing irreversible damage to protein structure and activity before they occur during the dehydration process

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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

The lyophilized exosomes retain significant biological activity, with up to 60% of CD73 enzymatic activity and cardioprotective potency after storage at 40°C for extended periods, compared to non-lyophilized exosomes stored at -80°C, demonstrating effective preservation of therapeutic efficacy.

Implementation Method 1

removing water from the frozen suspension by freeze drying

Methodology Applied
Scientific EffectFreeze-drying: Freeze Drying

Data Source

PatentEP3525806B1Method for lyophilising an exosome
Publication Date: 2023.02.15 AGENCY FOR SCI TECH & RES
  • EP3525806B1 patent drawingFigure 1
  • EP3525806B1 patent drawingFigure 2A
  • EP3525806B1 patent drawingFigure 2B

AI summary

The invention concerns a method for lyophilising exosomes by providing an exosome suspension in a lyophilisation buffer comprising a sugar at less than 10% w/v. The method is to preserve exosomes structural and biochemical integrity as well as the therapeutic efficacy for long term storage at ambient temperature. In one embodiment, the lyophilisation buffer comprises trehalose at 4% w/v. In another embodiment, removal of water from the frozen suspension deposits the exosomes on a biocompatible scaffold.