Mid-Air UV Curing for Monodisperse Microsphere Fabrication
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Solution Overview
Problem
Conventional methods for fabricating biodegradable microspheres for controlled-release drug delivery face challenges in precisely controlling sphere size and size distribution, leading to inefficient encapsulation and variable drug release rates, which affects the efficacy and administration of protein and peptide therapeutics.
Innovation Solution
The development of a system that crosslinks UV-curable polymer drops in mid-air and collects crosslinked particles using co-axial nozzles, allowing for the creation of structured particles with controlled sizes and phases, enabling precise control over microsphere fabrication and drug release kinetics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional emulsion or spraying techniques are used for microsphere fabrication, then production can be performed at bench and industrial scales, but sphere size and size distribution are poorly controllable with standard deviations equal to 25-50% of the mean diameter
Solution Approach 1:
The patent replaces conventional mechanical emulsion or spraying techniques with a digital light processing (DLP) based photopolymerization system. This substitution allows precise control of microsphere size and shape through digital modeling and selective UV curing, achieving manufacturing precision with standard deviations less than 5% of the mean diameter while maintaining scalability for industrial production
Solution Approach 2:
The invention utilizes changes in UV light exposure parameters, photopolymerization kinetics, and digital model specifications to precisely control microsphere fabrication. By adjusting exposure time, light intensity, and digital model parameters, the system achieves precise size control (standard deviation <5%) while maintaining high productivity through parallel fabrication capabilities
2Manufacturing precision
If spheres are made too small to pass through syringe needles, then administration becomes difficult, but if spheres are made larger to improve encapsulation efficiency, then release rate becomes too rapid and spheres may migrate from injection site
Solution Approach 1:
The patent applies local quality by creating microspheres with non-uniform drug distribution patterns through selective photopolymerization. The DLP system can concentrate drug payload in specific regions of the microsphere or create gradient distributions, allowing optimization of both encapsulation efficiency and controlled release kinetics while maintaining reliable administration through syringe needles
Solution Approach 2:
The invention performs preliminary action by pre-designing the microsphere structure and drug distribution pattern through digital modeling before fabrication. The DLP system fabricates microspheres with predetermined release profiles and optimal size (10-100 micrometers), ensuring both reliable injection through needles and controlled drug release without migration from the injection site
3Manufacturing precision
If conventional fabrication techniques are used, then polydisperse spheres are generated requiring filtration or sieving to isolate particles within desired size range, but this process wastes polymer and drug in spheres outside the size range
Solution Approach 1:
The patent replaces conventional mechanical fabrication followed by filtration/sieving with a DLP-based selective photopolymerization process. This substitution eliminates the need for post-fabrication size separation by directly fabricating monodisperse microspheres with precise size control (standard deviation <5%), thereby preventing waste of polymer and drug materials that would otherwise be discarded in conventional processes
4Productivity
If rapid hardening through UV crosslinking is implemented, then production rate and precision are significantly enhanced, but equipment complexity and process control difficulty increase
Solution Approach 1:
The patent applies universality by integrating multiple functions into the DLP fabrication system: digital modeling, selective UV light projection, photopolymerization initiation, and microsphere collection all occur in a single unified platform. This multi-functional integration achieves rapid production with precise size control while managing equipment complexity through system consolidation rather than separate processing stages
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 enhances the production rate and precision of microspheres, allowing for tailored drug release profiles and improved encapsulation efficiency, facilitating optimal targeting and administration of therapeutic agents.
Implementation Method 1
The droplets pass through a curing zone where they are cured by a UV curing system
Data Source
AI summary
Fabrication of functional polymer-based particles by crosslinking UV-curable polymer drops in mid-air and collecting crosslinked particles in a solid container, a liquid suspension, or an air flow. The particles can contain different phases in the form or layered structures that contain one to multiple cores, or structures that are blended with dissolved or emulsified smaller domains. A curing system produces ultraviolet rays that are directed onto the particles in the jet stream from one side. A reflector positioned on other side of the jet stream reflects the ultraviolet rays back onto the particles in the jet stream.