PLA Microneedle Patch with Ultrasonic Tip Separation
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Solution Overview
Problem
Existing transdermal microneedle technologies face challenges with biodegradable polymer microstructures bending or crushing upon skin penetration due to low mechanical strength, and hyaluronic acid structures experiencing difficulties in penetration and viscosity issues, limiting effective delivery of cosmetically active substances.
Innovation Solution
A transdermal microneedle patch combining poly-lactic acid (PLA) microneedles with epidermal growth factor (EGF) and hyaluronic acid (HA), where PLA microneedles are designed with a conical shape and coupled by physical or chemical adhesion, and ultrasonic waves are used to separate the needle tip from the base for efficient delivery into the dermis layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If biodegradable polymer microneedles are used for transdermal delivery, then safety and biocompatibility are improved, but mechanical strength is insufficient causing bending or crushing during skin penetration
Solution Approach 1:
The patent uses poly-lactic acid (PLA), a biodegradable polymer, as the microneedle material to achieve both biocompatibility and sufficient mechanical strength. PLA forms a composite structure that maintains integrity during skin penetration while being safely absorbed afterward, resolving the contradiction between safety and mechanical strength.
Solution Approach 2:
The patent optimizes the molecular weight and crystallinity parameters of poly-lactic acid to enhance mechanical strength while maintaining biodegradability. By controlling these material parameters, the microneedles achieve the necessary strength for skin penetration without sacrificing safety or biocompatibility.
2Strength
If hyaluronic acid with high molecular weight is used to improve mechanical strength, then strength is improved, but viscosity increases making structure formation difficult
Solution Approach 1:
The patent carefully controls the molecular weight parameter of hyaluronic acid to achieve an optimal balance. By selecting specific molecular weight ranges, the patent formulation achieves sufficient mechanical strength for microneedle structure while maintaining manageable viscosity for manufacturing and skin penetration.
3Reliability
If hypodermic needle injection is used for delivering cosmetically effective substances, then delivery effectiveness is improved, but patient pain and skill requirement increase
Solution Approach 1:
The patent divides the single large-bore hypodermic needle into multiple microneedles with diameters of only tens or hundreds of micrometers. This segmentation allows simultaneous penetration of the stratum corneum by numerous microneedles, delivering sufficient cosmetically effective substances while minimizing pain and eliminating the need for high injection skill.
Solution Approach 2:
The patent replaces the traditional hypodermic needle injection mechanism with a microneedle array patch system. This substitution eliminates the need for manual injection skills and reduces patient pain while maintaining effective delivery of cosmetically active substances through the skin barrier.
4Ease of operation
If microneedles with small diameter are used for pain-free application, then ease of operation is improved, but mechanical strength decreases causing bending or crushing
Solution Approach 1:
The patent employs poly-lactic acid, a biodegradable polymer with inherent mechanical strength, to construct the microneedles. This material choice enables the microneedles to maintain sufficient strength despite their small diameter (tens to hundreds of micrometers), preventing bending or crushing during application while remaining pain-free for patients.
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 microneedle patch enables pain-free, skill-free application with improved safety and convenience, facilitating rapid healing and effective delivery of PLA and EGF for collagen regeneration, maximizing cosmetic benefits.
Implementation Method 1
ultrasonic waves are used to separate the needle tip from the base for efficient delivery into the dermis layer
Data Source
AI summary
Proposed is a microneedle patch including at least one needle base disposed to protrude on a surface of the microneedle patch while having a patch layer as a flat layer, and made of hyaluronic acid (HA), and a needle tip disposed on an upper surface of the needle base, separated from the needle base by being inserted into a dermis layer of the skin, and made of the PLA, a biodegradable polymer. The PLA, a biodegradable polymer is characterized by after adding 0.01˜0.5 g of epidermal growth factor (EGF) to 0.1˜0.5 g of PLA and dissolving in 10 m of dichloromethane (DCM) as an organic solvent, mixing same with 50 m of 1 wt % poly vinyl alcohol (PVA) solution, and then mixing prepared PLA microparticles with a size of 30˜150 μm with 3 wt % carboxylic methyl cellulose (CMC) solution.