Encapsulation of Lactobacillus kefiri in alginate microbeads using a double novel aerosol technique

Carboxymethyl bacterial cellulose electrospun nanofibers loaded with zinc oxide nanoparticles and polyhexamethylene biguanide for wound healing promotion

This study explores the development of a novel wound dressing incorporating bacterial cellulose (BC) produced by Acetobacter xylinum, which was carboxymethylated to enhance its biomedical applicability. Zinc oxide nanoparticles (ZnONPs) were biosynthesized using a green method with Quercus infectoria gall extracts (QIG). The composite dressing, composed of BC and polyurethane (PU) nanofibers, was further functionalized with ZnONPs and polyhexamethylene biguanide (PHMB) to provide enhanced antibacterial and wound healing properties. The PU/BC/ZnONPs/PHMB nanofiber mat exhibited strong antibacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA), with inhibition zones of 28 and 29 mm for PU/BC/ZnONPs and PU/BC/ZnONPs/PHMB, respectively, surpassing the 12 mm inhibition zone of the Cefoxitin control. The nanofibers had an optimal mean diameter of 71.12 nm, ensuring a high surface area for cell attachment. Mechanical tests confirmed excellent tensile strength and flexibility, while an optimized water vapor transmission rate (∼2000-3000 g/m2/day) facilitated a moist wound environment for enhanced healing. L929 fibroblast studies demonstrated high cell viability (∼95-98%) and enhanced migration, confirming the nanofiber mat's biocompatibility. In vivo wound healing tests showed that PU/BC/ZnONPs/PHMB significantly accelerated wound closure, achieving 90-100% healing by day 10, outperforming PU and PU/BC groups. Bacterial counts were significantly reduced, with complete bacterial inhibition observed by day 5. In conclusion, the PU/BC/ZnONPs/PHMB nanofiber dressing demonstrated superior antibacterial activity, mechanical strength, moisture regulation, and wound healing potential, making it a promising candidate for advanced clinical wound management.

Oil-Water Emulsion Flocculation through Chitosan Desolubilization Driven by pH Variation

Water pollution is a major concern in our modern age. The contamination of water, as a valuable and often limited resource, affects both the environment and human health. Industrial processes such as food, cosmetics, and pharmaceutical production also contribute to this problem. Vegetable oil production, for example, generates a stable oil/water emulsion containing 0.5-5% oil, which presents a difficult waste disposal issue. Conventional treatment methods based on aluminum salts generate hazardous waste, highlighting the need for green and biodegradable coagulant agents. In this study, the efficacy of commercial chitosan, a natural polysaccharide derived from chitin deacetylation, has been evaluated as a coagulation agent for vegetable oil emulsions. The effect of commercial chitosan was assessed in relation to different surfactants (anionic, cationic, and nonpolar) and pH levels. The results demonstrate that chitosan is effective at concentrations as low as 300 ppm and can be reused, providing a cost-effective and sustainable solution for oil removal. The flocculation mechanism relies on the desolubilization of the polymer, which acts as a net to entrap the emulsion, rather than solely relying on electrostatic interactions with the particles. This study highlights the potential of chitosan as a natural and ecofriendly alternative to conventional coagulants for the remediation of oil-contaminated water.

Carboxymethylcellulose-Based Hydrogel Obtained from Bacterial Cellulose

In the present study, we have produced a sodium carboxymethylcellulose (CMC) hydrogel from a bacterial cellulose etherification reaction with chloroacetic acid in an alkaline medium. Bacterial cellulose (BC) was synthesized via economical and environmentally friendly methods using the Gluconacetobacter xylinus bacterium. After purification, freeze-drying, and milling, BC microparticles were dispersed in NaOH solution for different time periods before the etherification reaction. This has allowed the understanding of the alkalinization effect on BC modification. All synthesized CMC were soluble in water, and FTIR and XRD analyses confirmed the etherification reaction. The bath of BC in NaOH solution affects both molecular weight and degree of substitution. SEM analysis revealed the change of BC microstructure from fibrous-like to a smooth, uniform structure. The CMC-0 h allowed the production of crosslinked hydrogel after dehydrothermal treatment. Such hydrogel has been characterized rheologically and has shown a water absorption of 35 times its original weight. The optimization of the CMC produced from BC could pave the way for the production of ultrapure hydrogel to be applied in the healthcare and pharmaceutical industry.

Monitoring of Drug Release via Intra Body Communication with an Edible Pill

Oral drug administration provides a convenient and patient‐compliant way for drug delivery, especially for chronic diseases and prolonged pharmacological treatments. However, due to the repetitiveness of such therapeutic approach, the patients are led to neglect/forget the therapy affecting the healthcare delivery. Indeed, the non‐adherence to pharmacological prescriptions and the unknown amount of real‐time drug release result in a non‐compliant therapeutic drug level over the protracted therapies. The proposed technology will enable the monitoring of both pharmacological adherence and real‐time drug release. The approach exploits a passive intrabody communication (IBC) activation in order to enable an edible pill, realized starting from food additives and food‐grade materials, to monitor pharmacological adherence. Following activation, the signal is modulated by IBC coupling switching triggered by pill degradation in a gastrointestinal tract, resulting in a monitored drug release. The proof‐of‐concept is designed for a targeted release and monitoring of Metformin in the intestine. The system shows an in vitro limit of cumulative drug release detection of 18 µg mL−1 and a limit of real‐time drug release detection of 2 µg mL−1 min−1. This platform represents the first solution to monitor passive drug release in real‐time, from intake to complete absorption, enabling unique and long‐sought healthcare therapy and treatment opportunity.

Emerging Technologies and Coating Materials for Improved Probiotication in Food Products: a Review

From the past few decades, consumers' demand for probiotic-based functional and healthy food products is rising exponentially. Encapsulation is an emerging field to protect probiotics from unfavorable conditions and to deliver probiotics at the target place while maintaining the controlled release in the colon. Probiotics have been encapsulated for decades using different encapsulation methods to maintain their viability during processing, storage, and digestion and to give health benefits. This review focuses on novel microencapsulation techniques of probiotic bacteria including vacuum drying, microwave drying, spray freeze drying, fluidized bed drying, impinging aerosol technology, hybridization system, ultrasonication with their recent advancement, and characteristics of the commonly used polymers have been briefly discussed. Other than novel techniques, characterization of microcapsules along with their mechanism of release and stability have shown great interest recently in developing novel functional food products with synergetic effects, especially in COVID-19 outbreak. A thorough discussion of novel processing technologies and applications in food products with the incorporation of recent research works is the novelty and highlight of this review paper.

Co-encapsulation of probiotics with prebiotics and their application in functional/synbiotic dairy products

Oral administration of live probiotics along with prebiotics has been suggested with numerous beneficial effects for several conditions including certain infectious disorders, diarrheal illnesses, some inflammatory bowel diseases, and most recently, irritable bowel syndrome. Though, delivery of such viable bacteria to the host intestine is a major challenge, due to the poor survival of the ingested probiotic bacteria during the gastric transit, especially within the stomach where the pH is highly acidic. Although microencapsulation has been known as a promising approach for improving the viability of probiotics in the human digestive tract, the success rate is not satisfactory. For this reason, co-encapsulation of probiotics with probiotics has been practised as a novel alternative approach for further improvement of the oral delivery of viable probiotics toward their targeted release in the host intestine. This paper discusses the co-encapsulation technologies used for delivery of probiotics toward better stability and viability, as well the incorporation of co-encapsulated probiotics and prebiotics in functional/synbiotic dairy foods. The common encapsulation technologies (and the materials) used for this purpose, the stability and survival of co-encapsulated probiotics in the food, and the release behavior of the co-encapsulated probiotics in the gastrointestinal tract have also been explained. Most studies reported a significant improvement particularly in the viability of bacteria associated with the presence of prebiotics. Nevertheless, the previous research has mostly been carried out in the simulated digestion, meaning that future systematic research is to be carried out to investigate the efficacy of the co-encapsulation on the survival of the bacteria in the gut in vivo.

Encapsulation of Gold Nanostructures and Oil-in-Water Nanocarriers in Microgels with Biomedical Potential

Here we report the incorporation of gold nanostructures (nanospheres or nanorods, functionalized with carboxylate-end PEG) and curcumin oil-in-water (O/W) nanoemulsions (CurNem) into alginate microgels using the dripping technique. While gold nanostructures are promising nanomaterials for photothermal therapy applications, CurNem possess important pharmacological activities as reported here. In this sense, we evaluated the effect of CurNem on cell viability of both cancerous and non-cancerous cell lines (AGS and HEK293T, respectively), demonstrating preferential toxicity in cancer cells and safety for the non-cancerous cells. After incorporating gold nanostructures and CurNem together into the microgels, microstructures with diameters of 220 and 540 µm were obtained. When stimulating microgels with a laser, the plasmon effect promoted a significant rise in the temperature of the medium; the temperature increase was higher for those containing gold nanorods (11⁻12 °C) than nanospheres (1⁻2 °C). Interestingly, the incorporation of both nanosystems in the microgels maintains the photothermal properties of the gold nanostructures unmodified and retains with high efficiency the curcumin nanocarriers. We conclude that these results will be of interest to design hydrogel formulations with therapeutic applications.