Controlled release and antibacterial activity of nanofibers loaded with basil essential oil-encapsulated cationic liposomes against Listeria monocytogenes

Sodium alginate/carboxymethyl cellulose films embedded with liposomes encapsulated green tea extract: characterization, controlled release, application

To maintain the freshness of the fruit during storage, sodium alginate/carboxymethyl cellulose films embedded with pH-senstive liposomes encapsulated green tea extract were developed (SA/CMC/TP-Lip). An orthogonal design was used to optimise the preparation of TP-Lip and SA/CMC/TP-Lip was prepared through response surface. The stability of TP-Lip structure was measured. The morphology of SA/CMC/TP-Lip was characterised by SEM, and the mechanical properties and oxidation resistance of films were measured. Special attention was paid to the pH sensitivity of TP-Lip and the improvement of film properties. The zeta potential and encapsulation rate of TP-Lip were -45.85 ± 2.13 mV and 61.45 ± 0.23%. The average release rate of TP encapsulated into TP-Lip at pH 3 was 41.08%, an increase of 23.07% over pH 6 during 12 h. SEM and FTIR showed that TP-Lip was structurally stable and had good compatibility with SA/CMC. Tensile strength was increased by 30.55% and DPPH radical scavenging capacity was increased by 7.16% with the addition of TP-Lip. SA/CMC/TP-Lip is applied to blueberries to reduce their weight loss and improve the loss of freshness of blueberries during storage. Thus, SA/CMC/TP-Lip could provide a new way to extend active packaging materials and maintain fruit freshness during storage.

Enzyme-responsive controlled-release materials for food preservation and crop protection - A review

The adoption of environmentally friendly and efficient methods to control food spoilage and crop diseases has become a new worldwide trend. In the medical field, various enzyme-responsive controlled-release drug formulations have been developed for precision therapy. Recently, these materials and techniques have also begun to be applied in the fields of food preservation and agricultural protection. This review of contemporary research focuses on applications of enzyme-responsive controlled-release materials in the field of food preservation and crop protection. It covers a variety of composite controlled-release materials triggered by different types of enzymes and describes in detail their composition and structure, controlled-release mechanisms, and practical application effects. The enzyme-responsive materials have been employed to control foodborne pathogens, fungi, and pests. These enzyme-responsive controlled-release materials exhibit excellent capabilities for targeted drug delivery. Upon contact with microorganisms or pests, the polymer shell of the material is degraded by secreted enzymes from these organisms, thereby releasing drugs that kill or inhibit the organisms. In addition, multi-enzyme sensitive carriers have been created to improve the effectiveness and broad spectrum of the delivery system. The increasing trend towards the use of enzyme-responsive controlled-release materials has opened up countless possibilities in food and agriculture.

Fabrication of ɛ-Polylysine-Loaded Electrospun Nanofiber Mats from Persian Gum-Poly (Ethylene Oxide) and Evaluation of Their Physicochemical and Antimicrobial Properties

In the present study, electrospun nanofiber mats were fabricated by mixing different ratios (96:4, 95:5, 94:6, 93:7, and 92:8) of Persian gum (PG) and poly (ethylene oxide) (PEO). The SEM micrographs revealed that the nanofibers obtained from 93% PG and 7% PEO were bead-free and uniform. Therefore, it was selected as the optimized ratio of PG:PEO for the development of antimicrobial nanofibers loaded with ɛ-Polylysine (ɛ-PL). All of the spinning solutions showed pseudoplastic behavior and the viscosity decreased by increasing the shear rate. Additionally, the apparent viscosity, G', and G″ of the spinning solutions increased as a function of PEO concentration, and the incorporation of ɛ-PL did not affect these parameters. The electrical conductivity of the solutions decreased when increasing the PEO ratio and with the incorporation of ɛ-PL. The X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectra showed the compatibility of polymers. The antimicrobial activity of nanofibers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was investigated, and the samples loaded with ɛ-PL demonstrated stronger antimicrobial activity against S. aureus.

Current Applications of Liposomes for the Delivery of Vitamins: A Systematic Review

Liposomes have been used for several decades for the encapsulation of drugs and bioactives in cosmetics and cosmeceuticals. On the other hand, the use of these phospholipid vesicles in food applications is more recent and is increasing significantly in the last ten years. Although in different stages of technological maturity-in the case of cosmetics, many products are on the market-processes to obtain liposomes suitable for the encapsulation and delivery of bioactives are highly expensive, especially those aiming at scaling up. Among the bioactives proposed for cosmetics and food applications, vitamins are the most frequently used. Despite the differences between the administration routes (oral for food and mainly dermal for cosmetics), some challenges are very similar (e.g., stability, bioactive load, average size, increase in drug bioaccessibility and bioavailability). In the present work, a systematic review of the technological advancements in the nanoencapsulation of vitamins using liposomes and related processes was performed; challenges and future perspectives were also discussed in order to underline the advantages of these drug-loaded biocompatible nanocarriers for cosmetics and food applications.

Development of Nanofibers with Embedded Liposomes Containing an Immunomodulatory Drug Using Green Electrospinning

Conventional treatments for chronic wounds are often ineffective, thus new therapeutic approaches are needed, such as the delivery of immunomodulatory drugs that can reduce inflammation, restore immune cell function, and facilitate tissue regeneration. A potential drug for such an approach is simvastatin, which has major drawbacks including poor solubility and chemical instability. With the aim of developing a dressing for wound healing, simvastatin and an antioxidant were incorporated into alginate/poly(ethylene oxide) nanofibers by green electrospinning without the use of organic solvents, thanks to their prior encapsulation into liposomes. The composite liposome-nanofiber formulations exhibited fibrillar morphology (160-312 nm) and unprecedentedly high phospholipid and drug content (76%). Transmission electron microscopy revealed dried liposomes as bright ellipsoidal spots homogeneously distributed over the nanofibers. After nanofiber hydration, the liposomes reconstituted in two size populations (~140 and ~435 nm), as revealed by cutting-edge MADLS^® analysis. Lastly, in vitro assays demonstrated that composite liposome-nanofiber formulations are superior to liposomal formulations due to a better safety profile in keratinocytes and peripheral blood mononuclear cells. Furthermore, both formulations exhibited similarly advantageous immunomodulatory effects, measured as decreased inflammation in vitro. A synergistic combination of the two nanodelivery systems shows promise for the development of efficient dressings for chronic wound treatment.

Pheophorbide-a as a Light-Triggered Liposomal Switch: For the Controlled Release of Alpinia galanga (A. galanga) Essential Oil and Its Stability, Antioxidant, and Antibacterial Activity Assessment

In this study, Alpinia galanga essential oil liposomes (EO-Lip) were prepared with soybean lecithin and cholesterol as wall materials. A light-responsive liposome (EO-PLip) was designed for the controlled release of A. galanga oil based on the light-responsive properties of Pheophorbide-a. The dependence of Pheophorbide-a on illumination time was proved by UV spectroscopy. Characterization techniques such as UV spectroscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy demonstrated that the essential oils were successfully encapsulated in liposomes. Moreover, the particle size of EO-PLip was 166.30 nm, the polydispersity index was 0.22, the zeta potential was -49.50 mV, and the encapsulation efficiency was 30.83%. Both EO-Lip and EO-Plip have high sustained-release effects on essential oil and showed light-responsive release characteristics under infrared stimulation. The prepared liposomes had good storage stability at 4 °C for 28 d. EO-PLip showed excellent transient antioxidant and bacteriostatic properties based on the ability to respond to light and slow release. This EO-PLip provided a platform for essential oils and might be used as a potent and controllable solution.

Liposomes as Delivery System for Applications in Meat Products

In the meat industry, microbial contamination, and lipid and protein oxidation are important factors for quality deterioration. Although natural preservatives have been widely used in various meat products, their biological activities are often reduced due to their volatility, instability, and easy degradation. Liposomes as an amphiphilic delivery system can be used to encapsulate food active compounds, which can improve their stability, promote antibacterial and antioxidant effects and further extend the shelf life of meat products. In this review, we mainly introduce liposomes and methods of their preparation including conventional and advanced techniques. Meanwhile, the main current applications of liposomes and biopolymer-liposome hybrid systems in meat preservation are presented.