Spongelike Structure with Controlled Density
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Solution Overview
Problem
Current spongelike structures for cell cultivation and industrial applications face challenges in controlling apparent density, mimicking the extracellular matrix environment, and achieving high porosity and dispersity, which limits their effectiveness as scaffolds and fillers.
Innovation Solution
A spongelike structure with fibers of 1 nm to 50 μm in diameter, fixed in a dispersed state, and comprising thermoplastic polymers, with controlled apparent density and porosity, and a process involving freeze drying and pressurized steam treatment to produce a structure suitable for cell cultivation and industrial use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of stationary object
If fibers are thermally adhered in the molding box to form a spongelike structure, then the structure has low apparent density, but it is not easy to change the filling density of fibers and there is a limit for freely controlling apparent density
Solution Approach 1:
The patent applies parameter changes by controlling the freezing temperature (−80°C to −20°C) and drying conditions to adjust the apparent density of the spongelike structure. By changing these parameters, the filling density of fibers can be freely controlled while maintaining the low apparent density characteristic, thus resolving the contradiction between achieving low apparent density and enabling controllability of filling density.
2Quantity of substance
If a smaller number mean diameter of fiber is used to increase specific surface area, then the fiber fineness increases, but bulkiness of the spongelike structure is reduced
Solution Approach 1:
The patent utilizes phase transitions by freezing the dispersion media at controlled temperatures (−80°C to −20°C) to form ice crystals that act as spacers between fibers. This phase transition prevents fiber aggregation and maintains bulkiness even when using ultrafine fibers with small diameters, thus resolving the contradiction between increasing specific surface area and maintaining bulkiness.
Solution Approach 2:
The patent introduces dispersion media (water or organic solvents) as an intermediary between ultrafine fibers. These media prevent direct contact and aggregation of fibers with small diameters, allowing the maintenance of both high specific surface area and adequate bulkiness in the spongelike structure.
3Adaptability or versatility
If biomaterial such as collagen is extracted from animal to create cell culture scaffold, then the material can mimic cell environment, but there is a risk of infectious material from animals and problems with stability for long term storage
Solution Approach 1:
The patent replaces expensive, potentially unsafe animal-derived biomaterials with synthetic polymer fibers that can be produced sterile and stable. These synthetic fibers serve as disposable or long-lasting alternatives that eliminate the risk of animal-borne infectious materials while maintaining the ability to mimic cell environment through controlled fiber arrangement and porosity.
Solution Approach 2:
The patent creates composite structures by combining synthetic polymer fibers with dispersion media that can be removed to create porous frameworks. This composite approach allows the synthesis of materials that mimic the extracellular matrix environment while ensuring sterility and long-term stability through the use of synthetic, controllable components.
4Volume of stationary object
If fiber dispersion is dried to remove dispersion media to form spongelike structure, then the structure achieves high porosity, but the process requires precise control of drying conditions
Solution Approach 1:
The patent employs phase transitions by freezing the dispersion media at controlled temperatures (−80°C to −20°C) before drying. This pre-freezing step creates a structured ice framework that guides the formation of pores during subsequent drying, achieving high porosity while reducing the precision requirements of the drying process itself. The phase transition of water to ice acts as a template for the final porous structure.
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 resulting structure allows for high-density cell cultivation, mimics the in vivo environment, and exhibits improved dispersity and storage stability, making it suitable for various applications including cell therapy, regenerative medicine, and as a filler in resins and cosmetics.
Implementation Method 1
freezing the fiber dispersion at a temperature of not lower than −80° C. and not higher than −20° C.
Implementation Method 2
drying the frozen fiber dispersion to remove the dispersion media
Implementation Method 3
perform pressurized steam treatment after removal of the dispersion media
Data Source
AI summary
A spongelike structure or a powder having fibers three-dimensionally arranged therein with high dispersibility, whose apparent density can be designed depending on the purpose or utility, as well as a process producing it. A fiber dispersion in which fibers having a number mean diameter in a predetermined range are dispersed in a dispersion medium, and this fiber dispersion is dried to remove the dispersion medium, thereby, a spongelike structure and a powder are produced.