Thermal-Driven Curcumin Release Film with Dual-Mode Synergistic Antibacterial Behavior for Efficient Tangerine Preservation

Photodynamically activated chlorogenic acid-based antimicrobial packaging films for cherry preservation

Natural photosensitizers offer promising and sustainable solutions to the challenges of food preservation. This study investigates the potential of chlorogenic acid (CA), a naturally occurring phenolic compound with dual photoactive and antimicrobial properties. Under Xenon lamp irradiation (100 mW/cm2), CA at a concentration of 0.5 mg/mL demonstrated significant antimicrobial efficacy against both Staphylococcus aureus (106 CFU/mL) and Escherichia coli (105 CFU/mL). To enhance the practical applicability of CA for cherry preservation, CA was incorporated into agar (AG) films, which exhibited superior physicochemical and mechanical properties, including increased tensile strength and improved gas permeability. Implementation of CA-AG films prolonged the storage duration of cherries by 9 days through effective quality retention and suppression of microbial contamination. This research highlights the potential of CA as an environmentally friendly and functional solution for advanced food preservation technologies.

Flower like ZnO hybrid mediated visible light harvesting film with upgraded photodynamic antibacterial capacity for effective food preservation

Active food packaging film with light-driven antibacterial properties has inspired numerous interests for food preservation, while efficiently retains the photocatalytic ability remains highly challenging. This study pioneered an advanced visible light-driven photodynamic antibacterial packaging film (FZ-PC) employing an organic-inorganic hybrid strategy, meticulously engineering flower-like zinc oxide functional fillers (FZnO) with superior photoactivity and subsequently formulating a polyvinyl alcohol/sodium carboxymethyl cellulose (PC) mixed film matrix to enhance its physical and chemical properties. The boosting photodynamic activity of the FZnO results from the molecular-level optimization through citral modification. Collectively, the robust electrostatic interactions with bacteria and the enhanced generation capabilities of 1O2, •O2-, and •OH equip the FZ-PC film with superior bacterial inactivation properties, which can reduce the concentrations of Salmonella enteritidis and Staphylococcus aureus by 6 and 6.3 log, respectively. Furthermore, the FZnO-PC film showed lower UV transmittance, higher water contact angle and better mechanical strength. The enhanced antibacterial behavior and improved physicochemical properties of the composite film render it an ideal solution for fruit and vegetable preservation, significantly extending the storage life of cherry tomatoes from 4 days to 11 days. These findings suggest that the developed FZnO-PC film represents a promising advancement in packaging technology.

Visible light-driven multichannel concerted antibacterial films with Photodynamically enhanced self-cascading Chemodynamic actions for long-term preservation of perishable food

This work pioneered an innovative visible light-powered, self-cascading peroxide antimicrobial packaging system (RPFe-CS), featuring a photodynamic enhancement effect achieved through the demand-oriented design of riboflavin sodium phosphate and Fe coordination complexes (RPFe) fillers with photodynamic and peroxidase activities, and the ingenious selection of slightly acidic chitosan (CS) film matrix. In this system, the photo-responsive properties of RPFe particles not only generate the •O2-, •OH, and 1O2 required for photodynamic sterilization, but also the produced H2O2 serves as a necessary substrate for peroxidase to exert its bactericidal effect, endowing the packaging system with a "self-production and self-marketing" cascade process. The RPFe0.3-CS film achieved efficient eradication to bacteria and fungi reaching up to 99.9 % and 90.6 %, respectively, thereby demonstrating an excellent effect that significantly extends the storage period of cherry tomatoes by 1.5 times. These desirable properties underscore the significant advantages of RPFe0.3-CS film in addressing the challenges of food microbial spoilage.

Photothermal functionalized antibacterial packaging film with controllable release capability for fruit preservation

The traditional contact release active packaging film is easily restricted by the strict storage environment and designing a more intelligent release system to achieve lasting food preservation is still a challenge. Herein, a light-responsive thermal-controlled curcumin release packaging film was fabricated by integrating chitosan with Cu-MoOx and curcumin (CS/CMC). The addition of filler did not destroy the crystal structure and thermal stability of the chitosan matrix. CS/CMC film also possessed satisfactory visual identifiability (ΔE* ≥ 14.98), good light transmittance (T660 ≥ 79.99 %), enhanced mechanical properties (≥ 48.21 MPa), and excellent barrier performance against ultraviolet light (T280 ≤ 29.2 %), and water vapor (≤ 0.74 × 10-10 g m-1 s-1 Pa-1). Additionally, CS/CMC film obtained superior photothermal performance from Cu-MoOx and exhibited good photothermal stability. Benefiting from the photothermal activity, CS/CMC film realizes the intelligent and controllable release of curcumin. The released curcumin and photothermal showed synergistic antibacterial ability with an antibacterial rate of 99.33 % for E. coli and 99.23 % for S. aureus based on CS/CMC0.02 under near infrared (NIR) irradiation. Besides, CS/CMC0.02 film could also efficiently inhibit P. italicum and P. expansum under NIR irradiation. Tangerine treated with CS/CMC0.02 + NIR exhibited a longer shelf life and less nutrient loss than polyethylene (PE) film, verifying the good potential of CS/CMC0.02 as packaging film. Our release active packaging film based on photothermal agent provides a new insight to designing contactless intelligent active packaging.

Biobased Food Packaging Systems Functionalized with Essential Oil via Pickering Emulsion: Advantages, Challenges, and Current Applications

The development of innovative active food packaging is a promising strategy to mitigate food loss and waste while enhancing food safety, extending shelf life, and maintaining overall quality. In this review, Pickering emulsions with essential oils are critically evaluated as active additives for sustainable food packaging films, focusing on their antimicrobial and antioxidant properties, stabilization mechanisms, and physicochemical performances. A bibliometric approach was used to contextualize the current research landscape and new trends. Data were collected from the Web of Science and Scopus databases to find studies published between 2020 and 2024. The analysis of 51 articles shows that cinnamon, clove, and oregano are the most used essential oils, while cellulose and chitosan are the predominant polymer matrices. Pickering emulsions as stabilizers in food science represent a step forward in sustainable emulsion technology. The incorporation of essential oils into biobased films via Pickering emulsions can improve the mechanical and barrier properties, antimicrobial and antioxidant activities, and shelf life of foods. This approach offers a natural, environmentally friendly alternative to conventional materials and is in line with the 2030 Agenda goals for sustainability and responsible consumption. Recent advances show that composite particles combining polysaccharides and proteins have higher stability and functionality compared to single particles due to their optimized interactions at the interfaces. Future research should focus on developing scalable, cost-effective production methods and conducting comprehensive environmental testing and regulatory compliance, particularly for nanotechnology-based packaging. These efforts will be crucial to drive the development of safe and effective biobased active food packaging.

Photo-responsive Cu-tannic acid nanoparticle-mediated antibacterial film for efficient preservation of strawberries

The existing films used for fruit preservation suffer from insufficient preservation abilities. This study introduces Cu-tannic acid (Cu-TA) nanoparticles, synthesized from tannic acid (TA) and Cu2+, to enhance food packaging properties. Integrated into a chitosan-gelatin (CG) matrix, the resultant Cu-TA nanocomposite films exhibit superior antibacterial efficacy and killing rates of Escherichia coli and Staphylococcus aureus more than 99 %, and double the shelf life of strawberries, underscoring the exceptional freshness preservation capabilities of film. Additionally, the tensile strength of the Cu-TA nanocomposite films increased by 1.75 times, the DPPH radical scavenging percentage increased from 29.4 % to 68.4 %, and the water vapor permeability (WVP) decreased by about 60 % compared to the pure CG films. Comprehensive cytotoxicity and migration assessments confirm the safety of film, paving the way for their application in food packaging. The excellent performance of the Cu-TA nanocomposite films positions them as a formidable solution for protecting perishable food items.

Metal-phenolic networks spontaneously reinforced carrageenan-based packaging films with antibacterial and antioxidant properties

The burdens of microbial food safety and environmental contamination make it necessary to search sustainable, safe, antibacterial and antioxidant active food packaging materials. This contribution proposed the use of copper-ferulic acid networks (CuFA NWs) as antibacterial substances. By immobilizing CuFA NWs into carrageenan matrix, a CuFA network-reinforced carrageenan-based packaging film (Carr/CuFA) was obtained via spontaneously hydrogen bond and electrostatic interaction indicated by ATR-IR and XPS. Interestingly, the addition of CuFA NWs increased the mechanical strength, surface hydrophobicity, and water vapor barrier properties of the carrageenan-based film, and imparted the film with UV-shielding capacity. Importantly, the Carr/CuFAx film exhibited effective antioxidant activity, and antibacterial performance against four foodborne bacteria. As a result, after confirming the safety of Carr/CuFA3 films by releasing, hemolysis and cell viability experiments, the Carr/CuFA3 film exhibited great potential in the safety control and preservation of fresh fruit by using blueberry and cherry as model fruit. In summary, this work provides a feasible candidate for the preservation and contamination control of fresh fruit.

Smart conducting polymer innovations for sustainable and safe food packaging technologies

Biofilm formation on food packaging surfaces is a major issue in the industry, as it leads to contamination, reduces shelf life, and poses risks to human health. To mitigate these effects, developing smart coatings that can actively sense and combat microbial growth has become a critical research focus. This study is motivated by the need for intelligent packaging solutions that integrate antimicrobial agents and sensors for real-time contamination detection. It is hypothesized that combining conducting polymers (CPs) with nanomaterials can enhance antimicrobial efficacy while maintaining the mechanical integrity and environmental stability required for food packaging applications. Through the application of numerous technologies like surface modification, CP-nanoparticle integration, and multilayered coating, the antimicrobial performance and sensor capabilities of these materials were analyzed. Case studies showed a 90% inhibition of bacterial growth and a tenfold decrease in viable bacterial counts with AgNPs incorporation, extending strawberries' shelf life by 40% and maintaining fish freshness for an additional 5 days. Moreover, multilayered CP coatings in complex systems have been shown to reduce oxidative spoilage in nuts and dried fruits by up to 85%, while maintaining the quality of leafy greens for up to 3 weeks under suboptimal conditions. Environmental assessments indicated a 30% reduction in carbon footprint when CP coatings were combined with biodegradable polymers, contributing to a more transparent and reliable food supply chain. CP-based films integrated with intelligent sensors exhibit high sensitivity, detecting ammonia concentrations below 500 ppb, and offer significant selectivity for sensing hazardous gases. These findings indicate that CP-based smart coatings markedly enhance food safety and sustainability in packaging applications.

Use of Biomaterials in 3D Printing as a Solution to Microbial Infections in Arthroplasty and Osseous Reconstruction

The incidence of microbial infections in orthopedic prosthetic surgeries is a perennial problem that increases morbidity and mortality, representing one of the major complications of such medical interventions. The emergence of novel technologies, especially 3D printing, represents a promising avenue of development for reducing the risk of such eventualities. There are already a host of biomaterials, suitable for 3D printing, that are being tested for antimicrobial properties when they are coated with bioactive compounds, such as antibiotics, or combined with hydrogels with antimicrobial and antioxidant properties, such as chitosan and metal nanoparticles, among others. The materials discussed in the context of this paper comprise beta-tricalcium phosphate (β-TCP), biphasic calcium phosphate (BCP), hydroxyapatite, lithium disilicate glass, polyetheretherketone (PEEK), poly(propylene fumarate) (PPF), poly(trimethylene carbonate) (PTMC), and zirconia. While the recent research results are promising, further development is required to address the increasing antibiotic resistance exhibited by several common pathogens, the potential for fungal infections, and the potential toxicity of some metal nanoparticles. Other solutions, like the incorporation of phytochemicals, should also be explored. Incorporating artificial intelligence (AI) in the development of certain orthopedic implants and the potential use of AI against bacterial infections might represent viable solutions to these problems. Finally, there are some legal considerations associated with the use of biomaterials and the widespread use of 3D printing, which must be taken into account.