In hospital environments, air quality represents a critical factor in the prevention of nosocomial infections. The airborne transmission of bacteria and viruses occurs through respiratory aerosols, biological particulate matter, and ultrafine droplets that can remain suspended for prolonged periods and spread through ventilation systems. Although conventional filtration systems, such as HEPA filters and electrostatic or photocatalytic systems, offer high mechanical removal efficiency, they are limited in their ability to biologically inactivate pathogens and to integrate advanced bioactive functionalities. In this context, the use of fibroin as a biomaterial platform for filtration membranes represents an innovative strategy for the development of next-generation air filters capable of combining filtration efficiency, antimicrobial activity, and environmental sustainability.
Nanofibrous structure and particulate capture mechanisms
Nanofibrous membranes obtained through techniques such as aqueous electrospinning exhibit a highly porous three-dimensional structure characterized by fibers with nanometric diameters and a high specific surface area. This architecture enables effective interaction with airborne particles and microorganisms, allowing the capture of submicrometric particulate matter with relatively low pressure drop, a critical requirement for hospital HVAC systems. The ability to control porosity at the micro- and nanoscale makes these membranes particularly suitable for intercepting respiratory aerosols carrying viral pathogens, providing a higher level of protection compared to conventional polymeric materials.
Antibacterial functionalization and biofilm control
From a microbiological perspective, fibroin constitutes an extremely versatile matrix for antimicrobial functionalization. Its protein structure allows the stable immobilization of metallic nanoparticles, antimicrobial peptides, enzymes, and photosensitizing molecules, which can be used to generate reactive oxygen species, damage bacterial cell membranes, and prevent biofilm formation. These properties transform the filtration membrane from a passive barrier into a bioactive surface capable not only of trapping pathogens but also of reducing their viability and infectivity. In hospital settings, this feature is strategically important, since traditional filters can become reservoirs of viable microorganisms over time, contributing to cross-contamination.
Regarding viruses, fibroin functionalization enables advanced inactivation approaches, such as selective binding of viral particles via biomolecular ligands, integration of nanoparticles with antiviral properties, and activation of photocatalytic or photothermal processes for the deactivation of infectious particles. This approach paves the way for the development of bioactive antiviral filters, a crucial requirement for managing future pandemic emergencies and for protecting high-risk departments such as intensive care units and operating rooms.
Engineering advantages and environmental sustainability
From a biomaterials engineering standpoint, fibroin offers significant advantages in terms of sustainability, biocompatibility, and industrial scalability. As a biodegradable material, it reduces the environmental impact associated with disposable filtration devices, which currently represent a significant source of medical plastic waste. Fibroin-based membranes can be sterilized using different methodologies without significant loss of structural and functional properties, allowing integration with existing hospital protocols. Production processes based on aqueous solvents and moderate conditions make this biomaterial compatible with medical-grade industrial standards and sustainable manufacturing strategies.
Integration into hospital ventilation systems requires materials capable of maintaining high performance over time, with resistance to microbial colonization and mechanical stability under continuous airflow. Fibroin membranes, when used as functional layers in multilayer composite structures, can act as an active biological barrier, contributing to the reduction of circulating microbial load and preventing pathogen proliferation within HVAC systems. This approach represents a paradigm shift in filter design, transforming filters from simple mechanical components into biofunctional elements of the healthcare system.
Toward biointelligent filters
The near future will see the development of biointelligent filters capable of self-regeneration, integrating sensors for real-time monitoring of microbial contamination, and interacting with intelligent HVAC systems for dynamic air quality control. The combination with advanced nanomaterials could further enhance filtration and microbial inactivation properties, paving the way for a new generation of environmental biomedical devices.
The use of fibroin in antibacterial and antiviral air filters represents an emerging frontier in the control of hospital infections. The ability to combine high-efficiency filtration, bioactive functionality, and environmental sustainability makes this biomaterial a promising platform for the design of advanced ventilation systems, with the potential to significantly reduce airborne pathogen transmission and improve the safety of healthcare environments.
