The aim of this in vitro study is to prepare and characterize drug free and pentamidine loaded chitosan glutamate coated niosomes for intranasal drug delivery to reach the brain through intranasal delivery. Mucoadhesive properties and stability testing in various environments were evaluated to examine the potential of these formulations to be effective drug delivery vehicles for intranasal delivery to the brain. Samples were prepared using thin film hydration method. Changes in size and ζ-potential of coated and uncoated niosomes with and without loading of pentamidine in various conditions were assessed by dynamic light scattering (DLS), while size and morphology were also studied by atomic force microscopy (AFM). Bilayer properties and mucoadhesive behavior were investigated by fluorescence studies and DLS analyses, respectively. Changes in vesicle size and ζ-potential values were shown after addition of chitosan glutamate to niosomes, and when in contact with mucin solution. In particular, interactions with mucin were observed in both drug free and pentamidine loaded niosomes regardless of the presence of the coating. The characteristics of the proposed systems, such as pentamidine entrapment and mucin interaction, show promising results to deliver pentamidine or other possible drugs to the brain via nasal administration.

Chemical fingerprints of four different Satureja montana L. essential oils (SEOs) were assayed by an untargeted metabolomics approach based on Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometry (MS) coupled with either electrospray ionization or atmospheric pressure chemical ionization ion sources. Analysis and relative quantification of the non-polar volatile fraction were conducted by gas chromatography (GC) coupled to MS. FT-ICR MS confirmed significant differences in the polar metabolite composition, while GC-MS analyses confirmed slight fluctuations in the relative amount of major terpenes and terpenoids, known to play a key role in antimicrobial mechanisms. Oil in eater (O/W) nanoemulsions (NEs) composed by SEOs and Tween 20 or Tween 80 were prepared and analyzed in terms of hydrodynamic diameter, ζ-potential and polydispersity index. The results confirm the formation of stable NEs homogeneous in size. Minimum inhibitory and minimum bactericidal concentrations of SEOs were determined towards Gram-positive (Listeria monocytogenes, Staphylococcus aureus, Staphylococcus haemolyticus) and Gram-negative clinical isolates (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Serratia marcescens). Commercial SEO showed strongest antibacterial activity, while SEO 3 was found to be the most active among the lab made extractions. MIC and MBC values ranged from 0.39 to 6.25 mg·mL⁻¹. Furthermore, a SEO structured in NEs formulation was able to preserve and improve antimicrobial activity.

Brain infections as meningitis and encephalitis are attracting a great interest. Challenges in the treatment of these diseases are mainly represented by the blood brain barrier (BBB) that impairs the efficient delivery of even very potent drugs to reach the brain. The nose to the brain administration route, is a non-invasive alternative for a quick onset of action, and enables the transport of numerous medicinal agents straight to the brain thus workarounding the BBB through the highly vascularized olfactory region. In this report, Thymus vulgaris and Syzygium aromaticum essential oils (EOs) were selected to be included in chitosan coated nanoemulsions (NEs). The EOs were firstly analyzed to determine their chemical composition, then used to prepare NEs, that were deeply characterized in order to evaluate their use in intranasal administration. An in vitro evaluation against a collection of clinical isolated bacterial strains was carried out for both free and nanoemulsioned EOs. Chitosan coated NEs showed to be a potential and effective intranasal formulation against multi-drug resistant Gram-negative bacteria such as methicillin-susceptible Staphylococcus aureus and multi-drug resistant Gram-negative microorganisms including carbapenem-resistant Acinetobacter baumannii and Klebsiella pneumoniae.

Starch is a safe biopolymer, whose use for the production of scaffolds intended for deep wounds treatment is limited, due to its low mechanical and thermal properties. For this reason, until now, it has been used in low amounts and/or in combination with other biopolymers. The aim of the study was to produce thermoplastic filaments (TPS) with high starch content, useful for scaffolds production by Fusion Deposition Modelling 3D printing technique. TPS was obtained by hot melt extrusion from a mixture of starch (70 % w/w) and glycerol (30 % w/w) combined to cationic clay montmorillonite, citric acid and magnesium stearate to improve strength and processability. The prepared scaffold was characterized and compared to other two scaffolds, where the effect of the addition of polycaprolactone (PCL) or methylsulphonylmethane (MSM) (as thermostable model drug) to the blend was evaluated. The mechanical properties were investigated by Brillouin Light Scattering. In vitro studies highlighted that the scaffolds are: i) able to absorb simulated exudates (reaching a hydration of 35 % in 7 days); ii) safe on keratinocytes (viability > 70 %) stimulating their growth; iii) able to inhibit S. pyogenes growth.

This study investigated the thermal and spectroscopic properties of composites produced from Polyamide 12 (PA 12) and montmorillonite (MMT) or sepiolite (SEP) clays, for application in additive manufacturing. These properties are critical during the printing process, as they directly affect the balance between the energy input to the parts and their resulting mechanical properties and surface quality. The polymer/clay mixtures were prepared using a twin‐screw extruder, with PA 12 sourced from recycled material obtained through the Multi Jet Fusion (MJF) AM process. The clay concentrations evaluated were 2%, 5%, and 8%. The thermal stability of PA 12 improved with the incorporation of clays, with the effect being more pronounced in compositions containing MMT. This enhancement is attributed to the superior barrier effect provided by the layered structure of MMT compared to SEP. Under the experimental conditions employed in differential scanning calorimetry (DSC), no significant changes were observed in the crystallization and melting behavior of PA 12 upon filler incorporation, even at higher loading levels. These results indicate that the presence of the filler did not markedly affect the thermal transitions of the material. However, the addition of filler may restrict polymer chain mobility, acting as a physical barrier that hinders structural rearrangements and potentially influences the dynamics of the crystallization process. FTIR‐ATR spectra confirmed the preservation of the characteristic peaks of PA 12 and revealed additional bands associated with the clay structure, evidencing interactions between the composite components.

Starch is a safe and biocompatible excipient in pharmaceutical formulations. Introducing pores into its granules transforms it into a biodegradable carrier suitable for drug delivery. Various strategies have been developed to induce pore formation, including physical methods (e.g., microwave, ultrasound), chemical methods (e.g., solvent exchange), enzymatic methods, and synergistic methods. A novel, low‐cost and eco‐friendly method for preparing porous starch was developed by exploiting its ability to naturally swell when suspended in water under controlled conditions. Thanks to the coexistence of insoluble (amylopectin) and soluble (amylose) fractions, empty pores may be introduced via amylose solubilization. The influence of (i) starch concentration (1%–5% w/w), (ii) contact time (6–24 h), and (iii) temperature (60°C–80°C) on pore formation was experimentally evaluated. Preparation conditions were optimized at 5% w/w of starch, and 60°C temperature for 6 h; well‐defined pores with an average diameter of 118.6 nm were observed while maintaining granule integrity. Paracetamol was used to evaluate the effectiveness of porous starch as a drug carrier. Among the drug loading methods evaluated, spray drying led to more efficient and homogeneous results, with reduced crystallinity confirmed by DSC and Raman analyses.