G-CSF Polymer Conjugates for Prolonged Release

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Solution Overview

Problem

Current G-CSF therapies require frequent injections and complex synthetic processes for prolonged release forms, and existing conjugation methods often involve harsh conditions or denaturation, necessitating a more convenient and efficient approach.

Innovation Solution

Development of conjugates comprising a G-CSF moiety covalently attached to a nonpeptidic water-soluble polymer, either directly or through a spacer moiety, with specific attachment sites and linkages that allow for stable and efficient conjugation without harsh conditions, enabling a therapeutically effective and convenient administration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If G-CSF is administered as frequent daily injections to achieve therapeutic effect, then white blood cell replacement is effective, but patient convenience and compliance deteriorate

Engineering Contradiction:
Improvetherapeutic effectivenessVSAvoidpatient convenience
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The G-CSF is pre-conjugated to a polymer carrier before administration, creating a prolonged-release formulation that maintains therapeutic effect over an extended period without requiring frequent re-dosing. This preliminary preparation of the drug-delivery system resolves the contradiction by enabling less frequent administration while maintaining reliability.

Inventive Principle:
Principle #10Preliminary action

2Duration of action of moving object

If poly(lactic acid-co-glycolic acid) microspheres are used for prolonged release, then injection frequency is reduced, but synthetic complexity increases

Engineering Contradiction:
Improveprolonged release durationVSAvoidsynthetic process complexity
Core Design Contradiction:
Duration of action of moving objectVSDevice complexity

Solution Approach 1:

The invention extracts the prolonged-release function from the complex poly(lactic acid-co-glycolic acid) microsphere system and implements it through a simpler polymer conjugation approach. By using polymer conjugation instead of microsphere formation, the patent achieves prolonged release duration while eliminating the complex multi-step synthesis process required for microspheres.

Inventive Principle:
Principle #2Taking out (Extraction)

3Duration of action of moving object

If conventional conjugation methods are used to attach polymer to G-CSF, then prolonged release is achieved, but harsh conditions cause protein denaturation and aggregation

Engineering Contradiction:
Improvepharmacologic activity durationVSAvoidprotein stability
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The invention changes the reaction parameters by using mild conjugation conditions with pH control and appropriate buffering, thereby maintaining protein stability while achieving polymer attachment. This parameter optimization resolves the contradiction by enabling prolonged release formulation without causing denaturation or aggregation.

Inventive Principle:
Principle #35Parameter changes

4Duration of action of stationary object

If multiple synthetic steps are used to form microspheres, then prolonged release is achieved, but manufacturing efficiency decreases

Engineering Contradiction:
Improverelease durationVSAvoidmanufacturing efficiency
Core Design Contradiction:
Duration of action of stationary objectVSProductivity

Solution Approach 1:

The invention segments the synthesis process by using a single-step polymer conjugation reaction instead of multiple steps required for microsphere formation. This segmentation approach achieves prolonged release duration while significantly improving manufacturing efficiency by reducing process complexity and steps.

Inventive Principle:
Principle #1Segmentation

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 conjugates provide a stable and convenient form of G-CSF with prolonged activity, reducing the frequency of injections and simplifying the synthesis process, while maintaining therapeutic effectiveness by ensuring stable attachment and release profiles.

Implementation Method 1

a conjugate comprising a G-CSF moiety covalently attached, either directly or through a spacer moiety, to a nonpeptidic water-soluble polymer

Methodology Applied
Scientific EffectCovalent bonding: Chemical Bonding

Data Source

PatentEP2099495A2Conjugates of a g-CSF moiety and a polymer
Publication Date: 2009.09.16 NEKTAR THERAPEUTICS AL CORP

AI summary

Conjugates of a G-CSF moiety and one or more nonpeptidic water-soluble polymers are provided. Typically, the nonpeptidic water-soluble polymer is poly(ethylene glycol) or a derivative thereof. Also provided, among other things, are compositions comprising conjugates, methods of making conjugates, and methods of administering compositions comprising conjugates to a patient.