Unagglomerated Core/Shell Nanocomposite Particles via Silane Coupling
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Solution Overview
Problem
Current nanoparticle technologies for bioimaging and drug delivery face challenges such as solubility issues, physicochemical instability, agglomeration, and toxicity, particularly with quantum dots, which limit their effectiveness and safety for biomedical applications.
Innovation Solution
The development of stable, unagglomerated, and well-dispersed core/shell nanocomposite particles using silane coupling agents and high-performance liquid chromatography (HPLC) for synthesis, allowing for targeted drug delivery and bioimaging with enhanced stability and biocompatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If quantum dots are used for bioimaging, then imaging capability is improved, but agglomeration and toxicity occur
Solution Approach 1:
The patent introduces a silane coupling agent as an intermediary layer between the quantum dot core and the silica shell. This coupling agent (such as 3-aminopropyltriethoxysilane) provides chemical bonding sites that strongly attach to both the quantum dot surface and the silica precursor, creating a stable interface that prevents agglomeration while maintaining the quantum dot's imaging properties. The intermediary layer acts as a bridge that resolves the contradiction between maintaining imaging capability and preventing harmful agglomeration.
Solution Approach 2:
The patent creates a composite core/shell structure where a quantum dot core is encapsulated within a silica shell. This composite structure combines the advantages of both materials: the quantum dot provides superior imaging capability with tunable fluorescence, while the silica shell provides biocompatibility, colloidal stability, and prevents toxicity by containing the quantum dot material. The composite structure resolves the contradiction by integrating functional materials with protective materials.
2Stability of the object's composition
If silica shell is coated on nanocomposite particles, then stability is improved, but agglomeration occurs during synthesis
Solution Approach 1:
The patent applies preliminary action by modifying the nanocomposite particle surfaces with silane coupling agents before adding the silica precursor. This pre-modification creates reactive sites on the particle surfaces that promote uniform silica shell formation and prevent particle-particle interactions during the coating process. By performing the surface modification in advance, the patent prevents agglomeration from occurring during the silica shell formation process, while still achieving the desired stability enhancement.
Solution Approach 2:
The patent employs parameter changes by carefully controlling the pH, temperature, and concentration parameters during the silica shell formation process. The silane coupling agent modification changes the surface charge and hydrophilicity parameters of the particles, which prevents agglomeration. Additionally, the gradual addition of silica precursor and controlled hydrolysis conditions maintain particle dispersion while building the protective shell, resolving the contradiction between stability improvement and agglomeration prevention.
3Loss of substance
If conventional washing methods are used, then purification is achieved, but particles become agglomerated
Solution Approach 1:
The patent replaces mechanical washing methods (such as centrifugation and filtration) with a chemical purification approach using size-exclusion chromatography. In this method, the nanocomposite particles pass through a chromatography column where smaller impurities are retained while the larger particles elute in the void volume. This substitution of mechanical separation with a size-based separation mechanism achieves thorough purification without subjecting the particles to mechanical stress that would cause agglomeration, thus resolving the contradiction between purification and agglomeration prevention.
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 nanocomposite particles provide controlled, targeted, and sustained release of therapeutic agents, avoiding agglomeration and toxicity issues, with improved stability and biocompatibility, enabling effective bioimaging and drug delivery across biological barriers.
Implementation Method 1
treating the reverse micelle microemulsion with a silane coupling agent
Implementation Method 2
using high performance liquid chromatography (HPLC) for synthesis
Implementation Method 3
preparing a reverse micelle microemulsion containing nanocomposite particles
Data Source
AI summary
The present invention provides a method for the synthesis of unagglomerated, highly dispersed, stable core/shell nanocomposite particles comprised of preparing a reverse micelle microemulsion that contains nanocomposite particles, treating the microemulsion with a silane coupling agent, breaking the microemulsion to form a suspension of the nanocomposite particles by adding an acid/alcohol solution to the microemulsion that maintains the suspension of nanocomposite particles at a pH of between about 6 and 7, and simultaneously washing and dispersing the suspension of nanocomposite particles, preferably with a size exclusion HPLC system modified to ensure unagglomeration of the nanocomposite particles. The primary particle size of the nanocomposite particles can range in diameter from between about 1 to 100 nm, preferably from between about 10 to 50 nm, more preferably about 10 to 20 nm, and most preferably about 20 nm.