Professor Kevin Golovin, who leads the Durable Repellent Engineered Advanced Materials (DREAM) Laboratory at the University of Toronto, emphasizes the limitations of existing disinfection methods. “Currently, surfaces are mainly cleaned using harsh chemicals like bleach, which pose risks to the health of healthcare workers and can contribute to the evolution of resistant microbial strains,” he explains. This reality underscores the urgent need for safer, more efficient surface coatings that prevent microbial contamination without relying on toxic substances.

Golovin and his team specialize in designing engineered surfaces that repel specific molecules, with applications ranging from preventing ice accumulation on airplane wings to creating novel non-stick cookware. Their latest research, recently published in the Chemical Engineering Journal, directs this expertise toward preventing the attachment of bacteria-causing proteins, thereby inhibiting infection transmission via surface contact.

Key to this research is the role of proteins secreted by microbes. These proteins form sticky layers that facilitate bacterial adhesion to surfaces, enabling microbes to establish colonies and cause infections. By disrupting this initial protein layer formation, the transmission of disease-causing pathogens can be thwarted at a critical early stage, effectively altering the microbial lifecycle on contact surfaces.

The team focused on polydimethylsiloxane, or PDMS, known for its biocompatibility, transparency, and flexibility. PDMS sees widespread use in the medical field, from contact lenses to implantable devices. Despite its mild bacterial repellency, Golovin’s group hypothesized that they could amplify PDMS’s non-stick properties by manipulating its molecular architecture, creating a surface that would be inhospitable to protein adhesion.

Traditional use of PDMS involves cross-linking the polymer chains to create a solid silicone rubber. Instead, the researchers developed a “brush-like” surface composed of long, flexible PDMS chains that extend from the substrate. These mobile bristles mimic a liquid-like interface, differing fundamentally from rigid solid surfaces in their interaction with proteins.

This dynamic, brush-coated surface physically impedes bacteria’s proteins from acquiring a foothold. The PDMS chains’ mobility prevents proteins from establishing stable contact, causing them to detach easily. When bovine serum albumen (BSA)—a proxy for bacterial proteins—was tested, protein residues failed to form the typical “coffee ring” pattern seen on conventional coatings. Instead, the residue shrank as the droplet evaporated and finally flaked off effortlessly when disturbed.

What sets this innovative coating apart is its remarkable resistance to protein adhesion, surpassing even well-known substances like polyfluoroalkyl substances (PFAS), including Teflon. Importantly, whereas PFAS have garnered concern due to links to various health risks including carcinogenicity, PDMS presents a far safer profile for both healthcare environments and broader consumer applications.

The implications of this technology extend beyond hospital surfaces. By enabling easier cleaning with just water and eliminating the need for harsh chemical disinfectants, this PDMS brush coating offers a sustainable and non-toxic solution to one of healthcare’s most persistent challenges: infection control. Its scalable coating process positions it well for integration into medical devices, high-touch surfaces, and potentially single-use products.

Looking ahead, the University of Toronto team plans collaborations with microbiologists to verify the coating’s efficacy against real pathogenic bacteria, moving beyond protein proxies. Concurrently, industry partnerships are exploring commercialization opportunities, aiming to bring this protective technology into widespread use where it can make the greatest impact in safeguarding patients and healthcare workers.

Dr. Nektaria Markoglou of Meltech Innovation Canada, a key collaborator and funder, underscores the importance of such partnerships for innovation in infection prevention. She highlights how the research leverages expert surface engineering to develop more sophisticated and resilient antimicrobial products, reinforcing a commitment to science-driven solutions that protect public health.

Despite the enthusiasm, Golovin candidly notes that deploying the coating commercially will require optimizing manufacturing processes for cost efficiency and scalable application. Nonetheless, the prospect of significantly reducing hospital-acquired infections with a non-toxic, protein-repelling surface heralds a new era of safer healthcare environments and infection control strategies.

This advancement at the intersection of polymer engineering and biomedical applications exemplifies how targeted surface chemistry can transform everyday materials into advanced functional surfaces with critical, life-saving properties. The research marks a pivotal step towards safer, cleaner, and more sustainable health infrastructures worldwide.

Subject of Research: Development of non-toxic, protein-repelling surface coatings using polydimethylsiloxane (PDMS) brush-like polymers for infection prevention.

Article Title: University of Toronto Engineers Develop Innovative PDMS Brush Coating to Prevent Protein Adhesion and Combat Hospital-Acquired Infections

News Publication Date: Not specified in the content.

Web References:
– DREAM Laboratory: https://golovin.mie.utoronto.ca/
– Chemical Engineering Journal Paper: https://www.sciencedirect.com/science/article/pii/S1385894726008764
– DOI Link: http://dx.doi.org/10.1016/j.cej.2026.173417

Image Credits: Image by Mehdi Sadeghi / University of Toronto Engineering

Keywords

PDMS, protein adhesion, antimicrobial coatings, infection prevention, polymer engineering, hospital-acquired infections, non-toxic surface coatings, biomedical polymers, surface chemistry, microbial resistance, protein repulsion, material science

The research, conducted by a team led by Huang, Liu, and Tan, meticulously evaluated how vacuum packaging impacts hawthorn sticks—an increasingly popular snack and medicinal ingredient—over prolonged storage periods. Hawthorn, known for its rich antioxidant properties and health benefits, is particularly susceptible to rapid spoilage due to its high moisture content and biological composition. Conventional packaging methods often fall short in maintaining the textural integrity, flavor, and microbial safety of such perishable items, thus necessitating novel preservation strategies.

Central to their approach is the utilization of PA/PE composite films, which combine the excellent gas barrier properties of polyamide (PA) with the mechanical strength and flexibility of polyethylene (PE). This packaging matrix was hypothesized to not only inhibit oxygen ingress—a key factor in microbial proliferation and oxidative degradation—but also to maintain an anaerobic environment that further suppresses spoilage-causing organisms. The team embarked on comprehensive physicochemical and microbiological analyses to track the decline or preservation of hawthorn sticks’ quality indices throughout storage at chilled temperatures.

The analytical framework included assessments of moisture content, pH variation, titratable acidity, and total soluble solids, alongside detailed microbial enumeration focusing on total viable counts, yeast, and mold populations. These parameters collectively provide insights into the freshness, safety, and palatability of the fruit sticks over time. The researchers also compared vacuum-packaged samples to those stored in traditional atmospheric conditions to delineate the packaging’s true protective effect.

Findings revealed a remarkable retardation in microbial growth within vacuum-packaged hawthorn sticks. The total viable bacterial count remained significantly lower in the PA/PE vacuum group compared to controls throughout the storage duration. This microbial suppression translates not only to an extended shelf life but also markedly reduces the risk of foodborne illness—an essential consideration for consumer health. Particularly noteworthy was the diminished presence of spoilage yeasts and molds, notorious for causing off-flavors and texture degradation.

The physicochemical analyses corroborated these microbial findings. Moisture migration, a culprit of texture loss and microbial susceptibility, was minimized in vacuum packaging due to the films’ superior barrier properties. pH values in vacuum-packaged hawthorn sticks demonstrated greater stability, indicating limited organic acid breakdown and microbial metabolic activity. This biochemical steadiness maintains the desirable taste profile of the hawthorn sticks, which is pivotal for consumer acceptance and product differentiation in the competitive snack market.

Moreover, the titratable acidity levels—a key indicator of fruit freshness and fermentation status—were preserved at optimal values in the PA/PE vacuum group, unlike the atmospheric control where acid degradation was evident. This preservation points to reduced enzymatic and microbial activity, underscoring the effectiveness of the vacuum environment in maintaining metabolic stasis. Total soluble solids, associated with sweetness and flavor intensity, were also better retained, enhancing the sensory appeal of the product over time.

The technological implications of this study reach beyond hawthorn sticks. The success of PA/PE vacuum packaging implies broad applicability in preserving other moisture-sensitive fruit and vegetable products susceptible to microbial spoilage and physicochemical degradation. From an industrial perspective, adopting vacuum packaging technologies can substantially reduce food waste, optimize supply chain logistics, and cater to consumer demands for fresh-like quality in ready-to-eat snacks.

An in-depth examination of the vacuum packaging process revealed that the elimination of residual oxygen within the package reduces oxidative reactions, which are often initiated by oxygen radicals that accelerate nutrient loss and spoilage. The PA layer’s molecular density curbs oxygen transmission rates to nearly negligible levels, providing a controlled environment where aerobic microbes struggle to thrive. Meanwhile, the PE layer contributes to durability and seal integrity, ensuring the vacuum state persists throughout the storage period without compromise.

The study also touched on the sustainability aspect inherent in the use of PA/PE films. While multilayer films traditionally raise concerns over recyclability, advances in biodegradable and recyclable film composites are bridging this gap. Incorporating vacuum packaging aligned with environmentally conscious packaging trends could provide a dual solution—enhanced food preservation combined with reduced environmental footprint, a synergy increasingly emphasized in food technology innovation.

Consumer safety emerges as a pivotal advantage in light of growing foodborne pathogen outbreaks connected to minimally processed snacks. The researchers emphasized that vacuum packaging does not rely on chemical preservatives, which can raise health concerns, but rather leverages physical barriers to inhibit spoilage. This natural preservation modality aligns well with current market trends favoring “clean label” products free from artificial additives, potentially increasing market appeal and consumer trust.

The intricacies of hawthorn physiology, including its phenolic content and enzymatic activity, were also discussed in relation to packaging effects. The vacuum environment appeared to stabilize phenolic compounds, known for their antioxidant capacities and therapeutic benefits, by mitigating oxidation and enzymatic browning. Retaining such bioactive compounds elevates the product’s functional food status, catering to the burgeoning demand for health-promoting snacks.

Further, the team analyzed textural properties such as firmness and chewiness, which directly influence consumer perception and acceptance. Vacuum packaging preserved these sensory attributes better than conventional packaging, likely due to reduced moisture loss and microbial softening. These factors contribute synergistically to an enhanced eating experience, suggesting that vacuum packaging may help hawthorn sticks gain a stronger foothold in both domestic and international snack markets.

From a commercial viability standpoint, the study underscores the feasibility of integrating PA/PE vacuum packaging into existing production lines without significant capital remodeling. The film materials are compatible with current vacuum sealing machinery, and the cost implications are offset by the value addition through extended shelf life and improved product quality. The researchers posited that this balance between cost and benefit could accelerate adoption across sectors focused on fresh-cut fruits and health-oriented products.

Interestingly, the findings open avenues for further research exploring the synergies between vacuum packaging and other preservation techniques such as modified atmosphere packaging, natural antimicrobial coatings, or cold plasma treatment. Such combinations may amplify the shelf-life extension and safety outcomes beyond what vacuum packaging alone can achieve, crafting multifunctional preservation systems tailored for diverse food matrices.

This study’s comprehensive approach, merging microbiological, physicochemical, sensory, and industrial considerations, positions it as a landmark contribution to food science and packaging technology. It resonates profoundly with current imperatives to reduce food spoilage, minimize environmental impact, and deliver safe, nutritious, and enjoyable food products to consumers worldwide.

As the global demand for nutritious snacks rises, innovations like vacuum-packaged hawthorn sticks underscore the marriage of cutting-edge material science and food technology to fulfill future food security and quality challenges. The promise of safer, longer-lasting, and more flavorful fruit snacks not only benefits producers and retailers but ultimately empowers consumers with better food choices.

In conclusion, the implementation of PA/PE vacuum packaging represents a pivotal stride forward in preserving hawthorn sticks’ microbial safety and physicochemical qualities during storage. This technology arrives at a critical juncture where consumer health, food waste reduction, and sustainable packaging converge, offering a viable and scalable solution to perennial challenges in post-harvest fruit preservation. The reverberations of this advancement are set to echo across the landscape of fresh and minimally processed foods for years to come.

Subject of Research:
Preservation of hawthorn (Crataegus pinnatifida Bunge) sticks using vacuum packaging with polyamide/polyethylene (PA/PE) films to reduce microbial growth and physicochemical index losses during storage.

Article Title:
Vacuum packaging with PA/PE reduce the microbial level and physicochemical index losses of hawthorn (Crataegus pinnatifida Bunge) sticks during storage.

Article References:

Huang, S., Liu, Y., Tan, Q. et al. Vacuum packaging with PA/PE reduce the microbial level and physicochemical index losses of hawthorn (Crataegus pinnatifida Bunge) sticks during storage. Food Sci Biotechnol (2025). https://doi.org/10.1007/s10068-025-01929-5

Image Credits: AI Generated

DOI:
https://doi.org/10.1007/s10068-025-01929-5