Smart Probiotic Nonwoven Textiles for Skin Applications: Encapsulated Bacillus coagulans for Antimicrobial Activity and Dermatological Performance

The use of probiotic bacteria in dermatology has garnered increasing attention. This study presents a novel technology for developing functional nonwoven fabrics embedded with alginate-based hydrogel micro-flakes loaded with Bacillus coagulans bacteria. The micro-flakes exhibit a flat, irregular morphology that facilitates anchoring to fabric fibers, while the simple production process is amenable to industrial-scale manufacturing. The encapsulation efficiency was 90.6%, indicating successful entrapment of B. coagulans cells within the matrix, although the post-encapsulation survival rate was limited to ~ 30%. Probiotic micro-flakes (µFs) stored in suspension at 4 °C maintained viability above 10⁶ CFU/mL for at least 7 months. Furthermore, the µFs showed electrolyte-responsive disintegration, from which bacterial release was deduced under ionic conditions relevant to perspiration. Four types of nonwoven fabrics differing in their ratios of synthetic and natural fibers were studied. The bicomponent fabric (PE/PP-COT, 85:15) demonstrated superior loading and retention capabilities and the highest bacterial viability and was therefore selected for subsequent studies. This fabric was processed as probiotic dermatological face masks containing B. coagulans micro-flakes with a median size of approximately 70 μm (Dx50). The probiotic masks demonstrated broad-spectrum antimicrobial activity and met United States Pharmacopeia (USP) < 51 > effectiveness criteria for all five challenge microorganisms; European Pharmacopoeia criteria were met for Escherichia coli, Pseudomonas aeruginosa, and Candida albicans, but not for Staphylococcus aureus or Aspergillus brasiliensis. Human evaluations showed good skin tolerance, an immediate soothing effect, and significant improvements in hydration, transepidermal water loss, smoothness, redness, and several wrinkle-related parameters after repeated use. These findings support probiotic µF-embedded nonwoven textiles as a stable and scalable platform for antimicrobial and dermatological skin applications.