Keratin-Chitosan Microcapsules via Membrane Emulsification and Interfacial Complexation.

Area of Science:

• Biopolymer Science
• Materials Science
• Chemical Engineering

Background:

• Microplastic use in cosmetics is increasingly restricted.
• There is a need for sustainable and biodegradable alternatives for encapsulating active ingredients.
• Keratin and chitosan are abundant, renewable biopolymers with potential for microcapsule fabrication.

Purpose of the Study:

• To report the first continuous fabrication of stable microcapsules using keratin and chitosan.
• To investigate the formation mechanism and properties of these biopolymer microcapsules.
• To explore potential applications in cosmetic formulations.

Main Methods:

• Membrane emulsification technique for continuous microcapsule production.
• Utilizing electrostatic interactions between keratin and chitosan to form polyelectrolyte complexes.
• Characterization of microcapsule size, stability, and release properties.

Main Results:

• Successfully fabricated stable keratin-chitosan microcapsules (30-120 μm) via continuous membrane emulsification.
• Achieved high productivity of up to 4.5 million capsules per minute in the continuous system.
• Demonstrated tunable release properties, with cross-linking enhancing stability and force-induced release.

Conclusions:

• Continuous fabrication of keratin-chitosan microcapsules is feasible and efficient.
• These biodegradable microcapsules are promising for cosmetic applications, offering ingredient protection and controlled release.
• Potential for mechanical rupture release mechanism aligns with cosmetic product usage.