5-ALA Derivative Compounds for Selective Photodynamic Therapy
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Solution Overview
Problem
There is a need for alternative photosensitizers or precursors for photodynamic treatment (PDT) that can effectively target cancerous and metabolically active cells, as existing agents like 5-aminolevulinic acid (5-ALA) and its derivatives have limitations in selectivity and efficacy.
Innovation Solution
Development of compounds according to the general formula I, which include hydrophilic groups and specific alkyl, cycloalkyl, aryl, and aralkylene linkages, acting as precursors that can be converted into photosensitizers within cells, thereby enhancing their pharmacological properties for PDT and photodynamic diagnosis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing photosensitizing agents like 5-ALA and its derivatives are used, then photodynamic treatment can be performed, but selectivity and efficacy are limited
Solution Approach 1:
The patent modifies the chemical structure of 5-ALA by introducing various ester groups (R1) and linker moieties (X) to create compounds of formula I. These structural parameter changes enhance cellular uptake, conversion efficiency to photosensitizers, and selectivity for cancerous cells while maintaining the core photodynamic mechanism
Solution Approach 2:
The invention creates composite molecular structures combining the 5-ALA core with diverse ester groups and linker moieties. This composite approach allows optimization of pharmacokinetic properties, cellular penetration, and photosensitizer generation while providing a family of related compounds with potentially different selectivity profiles
2Reliability
If compounds of formula I are developed as new photosensitizer precursors, then pharmacological properties are improved, but complexity of compound structure increases
Solution Approach 1:
The compound of formula I is segmented into distinct functional modules: the 5-ALA core, the ester group (R1), and the linker moiety (X). This segmentation allows independent optimization of each component's properties while maintaining overall molecular functionality for cellular uptake and photosensitizer conversion
Solution Approach 2:
The linker moiety X acts as an intermediary structure connecting the 5-ALA core to the ester group R1. This intermediary element facilitates controlled conversion to photosensitizers and enables tuning of pharmacokinetic properties without disrupting the core photodynamic mechanism
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
These compounds demonstrate improved pharmacological properties, allowing for effective uptake and conversion into photosensitizers, which are useful in PDT and PDD, particularly in treating cancerous and non-cancerous conditions, including infections and inflammatory cells, with potential for alternative treatments resistant to antibiotic-resistant bacteria.
Implementation Method 1
PDT involves the administration of a photosensitiser or a precursor thereof (i.e. a 'photosensitising agent') to an area of interest. The photosensitiser or precursor thereof is taken up into the cells, where a precursor of a photosensitiser is converted into a photosensitiser. Upon exposure of the area of interest to light, the photosensitiser is excited
Implementation Method 2
When the photosensitiser and an oxygen molecule are in proximity, an energy transfer can take place that allows the photosensitiser to relax to its ground singlet state, and create an excited singlet state oxygen molecule. Singlet oxygen is a very aggressive chemical species and will very rapidly react with any nearby biomolecules
Data Source
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AI summary
The invention relates to new derivatives of 5-aminolevulinic acid (5-ALA) and their use as photosensitizing agents. In particular, it relates to compounds of general formula I and their pharmaceutically acceptable salts, to methods for preparing such compounds and their medical and cosmetic use, for example in methods of photodynamic therapy and diagnosis: wherein R1 represents a hydrogen atom or an optionally substituted alkyl or cycloalkyl group; R2, each of which may be the same or different, represents a hydrogen atom or an optionally substituted alkyl group; and X is a linking group.