PSA-TMC Nanoparticles for Stable Drug Delivery

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Chitosan-based nanoparticles face limitations in stability, size, and charge, leading to poor efficacy and increased clearance in systemic drug delivery, particularly for treating autoimmune diseases like rheumatoid arthritis, due to their cationic nature and propensity to aggregate.

Innovation Solution

The development of poly(sialic acid) (PSA)-N,N,N-trimethylchitosan (TMC) nanoparticles, synthesized by complexing positively charged TMC with negatively charged PSA at a 0.5:1 weight ratio, resulting in nanoparticles with a favorable size of approximately 100 nm and zeta potential above 30 mV, enhancing stability and targeting capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If chitosan-based nanoparticles are used for drug delivery, then biocompatibility and bioadhesion are improved, but stability under physiological conditions deteriorates

Engineering Contradiction:

ImprovebiocompatibilityVSAvoidstability under physiological conditions

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent combines chitosan with sialic acid to create a composite nanoparticle system. The chitosan provides biocompatibility and bioadhesion, while the sialic acid component enhances stability under physiological conditions by reducing aggregation and improving circulation. This composite approach allows both properties to coexist in the final nanoparticle formulation.

Inventive Principle:

Principle #40Composite materials

2Productivity

If chitosan-based nanoparticles are used for drug delivery, then uptake by diseased tissue is improved, but clearance by reticuloendothelial system increases

Engineering Contradiction:

Improveuptake by diseased tissueVSAvoidcirculation time

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent modifies the surface charge parameter of the nanoparticles by incorporating sialic acid, which has negative charge. This changes the overall zeta potential of the nanoparticle system, reducing the strong cationic charge of pure chitosan. The modified charge parameter allows the nanoparticles to maintain uptake efficiency while avoiding excessive recognition and clearance by the reticuloendothelial system, thereby extending circulation time.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If chitosan-based nanoparticles are used for drug delivery, then bioavailability is improved, but size is too large for systemic drug delivery

Engineering Contradiction:

ImprovebioavailabilityVSAvoidnanoparticle size

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The patent employs a segmented or modular nanoparticle structure where chitosan and sialic acid components are organized in a specific architecture. This segmentation allows the nanoparticle to achieve an optimal size range for systemic delivery while maintaining the functional benefits of both components. The segmented structure prevents excessive aggregation and enables better control over final particle dimensions.

Inventive Principle:

Principle #1Segmentation

4Quantity of substance

If chitosan-based nanoparticles are used for drug delivery, then solubility is improved, but aggregation propensity increases

Engineering Contradiction:

ImprovesolubilityVSAvoidaggregation resistance

Core Design Contradiction:

Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The sialic acid component acts as an intermediary between the chitosan polymer chains and the physiological environment. It mediates the interaction by providing steric stabilization and electrostatic repulsion, preventing direct aggregation of chitosan molecules. This intermediary layer maintains solubility while simultaneously preventing aggregation, resolving the contradiction between these two 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

The PSA-TMC nanoparticles demonstrate improved stability, controlled release of methotrexate, and reduced cytotoxicity, facilitating targeted drug delivery with minimal side effects and increased bioavailability, effectively addressing the limitations of chitosan-based systems.

Implementation Method 1

synthesized by complexing positively charged TMC with negatively charged PSA

Methodology Applied

Scientific EffectIonic interaction: Ion Repulsion/Attraction

Data Source

PatentUS9241913B2Polysialic acid-based N-trimethyl chitosan gel nanoparticles for systemic drug delivery

Publication Date: 2016.01.26 SYRACUSE UNIVERSITY

AI summary

Gel nanoparticles for encapsulating and delivering a pharmaceutical compound to a patient. The nanoparticles are formed from N-trimethyl chitosan and polysialic acid, preferably in the presence of sodium tripolyphosphate. A ratio of polysialic acid to N-trimethyl chitosan of about 0.5 to 1 produces nanoparticles having diameter of about 100 nm (plus or minus 25 nm) and a zeta potential above 30 milivolts that can stability contain a pharmaceutical compound, such as methotrexate, for delivery to a patient.