Polypeptide Multilayer Films via Polymeric Precipitant

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Solution Overview

Problem

There is a need for alternative methods to achieve direct and efficient retention of functional bioactive macromolecules, such as proteins, in engineered biodegradable polypeptide films and microcapsules, as existing methods face challenges in maintaining the stability and controlled release of these molecules in vivo.

Innovation Solution

The method involves depositing layers of oppositely charged polyelectrolytes on a substrate in the presence of a polymeric precipitant, using polypeptides with specific amino acid sequence motifs and charge properties to form stable polyelectrolyte multilayer films and microcapsules that encapsulate bioactive molecules, enhancing their retention and controlled release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If polyelectrolyte multilayer films are formed by layer-by-layer assembly to encapsulate bioactive molecules, then the stability and controlled release of molecules is improved, but the retention of functional bioactive macromolecules during fabrication deteriorates

Engineering Contradiction:
Improvestability and controlled release of bioactive moleculesVSAvoidretention of functional bioactive macromolecules
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent introduces a polymeric precipitant as an intermediary substance during the layer-by-layer assembly process. This precipitant mediates between the polyelectrolyte deposition process and the bioactive molecules, allowing the films to form while preventing molecule loss. The precipitant creates conditions that favor film formation without compromising the integrity or retention of the encapsulated bioactive macromolecules.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the physical-chemical parameters of the deposition environment by adding a polymeric precipitant. This changes the solubility and interaction characteristics of the system, enabling simultaneous achievement of good film formation and high molecule retention. The parameter change allows the process to operate in a regime where both encapsulation efficiency and molecule retention are optimized.

Inventive Principle:
Principle #35Parameter changes

2Duration of action of stationary object

If multiple layers of polyelectrolytes are deposited to enhance encapsulation stability, then the preservation of function is improved, but the loss of bioactive molecules increases

Engineering Contradiction:
Improvepreservation of functionVSAvoidloss of bioactive molecules
Core Design Contradiction:
Duration of action of stationary objectVSLoss of substance

Solution Approach 1:

The polymeric precipitant serves as a protective intermediary during multiple deposition cycles. As layers are sequentially added to enhance stability and function preservation, the precipitant continuously prevents bioactive molecule loss that would normally occur during each deposition step. This allows the accumulation of multiple stabilizing layers without proportional increase in molecule loss.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If polypeptide films are used for encapsulation to achieve biodegradability and environmental benignity, then the biocompatibility is improved, but the efficiency of bioactive molecule retention deteriorates

Engineering Contradiction:
Improvebiocompatibility and environmental benignityVSAvoidretention of bioactive molecules
Core Design Contradiction:
Adaptability or versatilityVSLoss of substance

Solution Approach 1:

The polymeric precipitant acts as a mediator that bridges the gap between the biodegradable polypeptide film requirements and the need for efficient molecule retention. It enables the use of environmentally benign polypeptide materials while compensating for their lower inherent retention efficiency through the precipitant's film-forming and protective properties.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach significantly improves the retention of bioactive molecules during film fabrication, maintaining their functionality and stability, and allows for controlled release, as demonstrated by the encapsulation of glucose oxidase, which retains up to 70% of its activity after multiple bilayer deposition.

Implementation Method 1

In electrostatic layer-by-layer self-assembly (ELBL), the physical basis of association of polyelectrolytes is electrostatics. Film buildup is possible because the sign of the surface charge density of the film reverses on deposition of successive layers.

Methodology Applied
Scientific EffectElectrostatic attraction: Electrostatics

Implementation Method 2

The first layer polyelectrolyte, the second layer polyelectrolyte, or both, is deposited on the substrate in the presence of a polymeric precipitant

Methodology Applied
Scientific EffectPrecipitation: Precipitation

Data Source

PatentEP1957050B1Polypeptide films and methods
Publication Date: 2014.01.01 LOUISIANA TECH UNIVERSITY FOUNDATION
  • EP1957050B1 patent drawingFigure 1
  • EP1957050B1 patent drawingFigure 2
  • EP1957050B1 patent drawingFigure 3

AI summary

Disclosed herein is a method of making a film, the method comprising depositing a first layer polyelectrolyte on a surface of a substrate to form a first layer; and depositing a second layer polyelectrolyte on the first layer polyelectrolyte to form a second layer. The first layer polyelectrolyte, the second layer polyelectrolyte, or both, is deposited on the substrate in the presence of a polymeric precipitant; and the first layer polyelectrolyte and the second layer polyelectrolyte have net charges of opposite polarity. Also disclosed are methods of improving bioactive molecule retention during fabrication of a polyelectrolyte multilayer film.