Diabetic foot ulcers (DFU) are among the most common complications in diabetic patients and affect 6.8% of people worldwide. Challenges in the management of this disease are decreased blood diffusion, sclerotic tissues, infection, and antibiotic resistance. Hydrogels are now being used as a new treatment option since they can be used for drug delivery and to improve wound healing. This project aims to combine the properties of hydrogels based on chitosan (CHT) and the polymer of β cyclodextrin (PCD) for local delivery of cinnamaldehyde (CN) in diabetic foot ulcers. This work consisted of the development and characterisation of the hydrogel, the evaluation of the CN release kinetics and cell viability (on a MC3T3 pre-osteoblast cell line), and the evaluation of the antimicrobial and antibiofilm activity (S. aureus and P. aeruginosa). The results demonstrated the successful development of a cytocompatible (ISO 10993-5) injectable hydrogel with antibacterial (99.99% bacterial reduction) and antibiofilm activity. Furthermore, a partial active molecule release and an increase in hydrogel elasticity were observed in the presence of CN. This leads us to hypothesise that a reaction between CHT and CN (a Schiff base) can occur and that CN could act as a physical crosslinker, thus improving the viscoelastic properties of the hydrogel and limiting CN release.

Polymeric scaffolds are promising in tissue engineering due to their structural similarity to extracellular matrix components. This study aimed to design freeze-dried hydrogels based on chitosan (CHT) and hyaluronic acid (HA). Chitosan-based gels were crosslinked with oxidized maltodextrin (MDo) before the freeze-drying step, resulting in spongy porous scaffolds. Based on the state-of-the-art, our hypothesis was that crosslinking would increase scaffold stiffness and delay the degradation of the CHT:HA resorbable scaffolds swelled in a hydrated physiological environment. The physicochemical and mechanical properties of crosslinked CHT- and CHT:HA-based scaffolds were analyzed. Hygroscopic and swelling behavior were assessed using dynamic vapor sorption analysis and batch studies. Degradation was evaluated under different conditions, including in phosphate-buffered saline (PBS), PBS with lysozyme, and lactic acid solutions, to investigate scaffold resistance against enzymatic and acidic degradation. The porosity of the spongy materials was characterized using scanning electron microscopy, while dynamic mechanical analysis provided information on the mechanical properties. Crosslinked scaffolds showed reduced swelling, slower degradation rates, and increased stiffness, confirming MDo as an effective crosslinking agent. Scaffolds loaded with ciprofloxacin (CFX) demonstrated their ability to deliver therapeutic agents, as the CFX loading capacity was promoted by CHT–CFX interactions. Microbiologic investigation confirmed the results. Finally, cytotoxicity tests displayed no toxicity. In conclusion, MDo-crosslinked CHT and CHT:HA scaffolds exhibit enhanced stability, functionality, and mechanical performance, making them promising for cartilage tissue engineering.

Electron Beam (EB) irradiation was utilized to decontaminate model systems of industrial polymers that contain a brominated flame retardant (BFR). Acrylonitrile-butadiene-styrene (ABS) and Polycarbonate (PC) are two types of polymers commonly found in Waste Electrical and Electronic Equipment (WEEE). In this study, these polymers were exposed to EB irradiation to degrade DecaBromoDiphenylEther (DBDE), one of the most toxic BFRs. Fourier-transform infrared spectroscopy analysis demonstrated an 87% degradation rate of DBDE for the ABS-DBDE system and 91% for the PC-DBDE system following an 1800 kGy irradiation dose. Thermal analysis using Differential Scanning Calorimetry revealed the presence of crosslinking in ABS and a minor reduction in the glass transition temperature of PC after EB processing. Polymers exhibited thermal stability after photolysis, as indicated by thermogravimetric analysis. In summary, EB irradiation had no impact on the overall thermal properties of both polymers. High-resolution mass spectrometry analysis has confirmed the debromination of both ABS-DBDE and PC-DBDE systems. Therefore, the results obtained are promising and could offer an alternative approach for removing bromine and other additives from plastic E-waste.

The thermal degradation behavior of Poly(2-ethyl hexyl hcrylate) (Poly(2-EHA)), blended with a commercially available nematic liquid crystal (LC) mixture, was investigated by thermal gravimetric analysis (TGA). Different heating rates, ranging from 5 to 200 °C/min, were applied under an inert atmosphere. Based on the TGA results, activation energies (E_α) at different conversion rates (α) were determined using three integral isoconversion methods: Flynn-Wall-Ozawa (FWO), Tang, and Kissinger-Akahira-Sunose (KAS). It can be noticed that the global evolution of these activation energies was the same for the three models. The coefficient of determination R² presented values generally higher than 0.97. Using these models, the E_α value for the LC remains constant at 64 kJ/mol for all conversions rates. For the polymer Poly(2-EHA), applying the Tang and FWO models, the activation energy presents a variation ranging from 80 kJ/mol, for conversion α = 0.1, to 170 kJ/mol, for α = 0.9. For the third model (KAS), this energy varies between 80 and 220 kJ/mol in the same range of α.

The chemical structure of low‐density polyethylene (PE), which is responsible for its incompatibility and durability, has a significant impact on the degradation process. The present study examined the effects of combining plasma treatment technology with the addition of a prooxidant (designated hereafter as Ox) into a PE matrix on the hydrophilicity and degradation of resulting blends. The films of the PE/poly( ε ‐caprolactone) (PCL) and Ox‐PE/PCL blends and their homopolymers were subjected to radiofrequency plasma (RFP) treatment. Subsequently, the resulting samples were subjected to a compost test at 58 ^° C ± 2 ^° C for a period of 24 months. Contact angle measurements, Fourier‐transform infrared spectroscopy, and thermogravimetric analysis were employed to evaluate the surface properties of the samples both before and after plasma treatment. Moreover, the biodegradation of all samples was assessed through weight loss and Fourier‐transform infrared spectroscopy. The findings substantiate that surface treatment with RFP markedly diminished the contact angle with water, thereby transforming hydrophobic surfaces into hydrophilic surfaces. Following exposure to RFP and subsequent storage in air for 60 days, the samples exhibited a markedly increased hydrophilic nature. Among the various films, the Ox‐PE75/PCL25 blend demonstrated the most pronounced reduction in weight loss, which underscores the synergistic impact of oxidation and surface treatment on the samples.