Stefania Cometa

This study reports the development of injection-moulded bioplastics based on porcine plasma proteins (PPP) blended with carboxymethyl chitosan (CMCH), as sustainable absorbent materials for hygienic-sanitary applications as alternative to conventional polyurethane foams. Glycerol (Gly) was used as a plasticizer, while sodium carbonate (SC) was employed to induce porosity, and genipin (G) as a natural crosslinking agent. The materials were characterized by FTIR, XPS, thermogravimetric analysis, dynamic mechanical analysis, tensile testing, and scanning electron microscopy. The liquid absorption assays included water uptake capacity (WUC), free swell capacity (FSC), centrifuge retention capacity (CRC), absorption under load (AUL), and rewet performance. SC incorporation increased porosity and free swelling, so that PPP-CMCH/Gly_SC reached 3600 WUC%. Conversely, G-crosslinking reduced soluble matter loss and enhanced stiffness and AUL, with PPP-CMCH/Gly/G_SC formulation achieved a superior balance reaching an AUL of 5.97 g/g and rewet values as low as 0.77 g. This bioplastic reached FSC, CRC and AUL values of about 52%, 22% and 100% with respect to a commercial PU foam. Overall, the combined porosity-inducing and crosslinking strategy enabled a balance between absorbency and mechanical integrity.

Tepals of the Crocus sativus flower constitute the most abundant floral residue during saffron production (350 kg tepals/kg stigmas). Being a natural source of polyphenols with antioxidant properties, they can be reused to create potentially valuable products for pharmaceutical applications, generating a new income source while reducing agricultural bio-waste. In this work, composite hydrogels based on blends of pectin and gellan gum containing Crocus sativus tepal extract (CSE) have been proposed for the regeneration and healing of cutaneous wounds, exploiting the antioxidant properties of CSE. Various physico-chemical and mechanical characterizations were performed. The skin permeation of CSE was investigated using Franz cell diffusion system. The composite films were cytocompatible and able to counteract the increase in ROS, restore the production of matrix proteins, and favor wound closure. To conclude, CSE-loaded composite films represent a promising strategy to promote the body’s natural healing process. In addition, by reusing saffron tepals, not only can we develop new, sustainable treatments for skin diseases, but we can also reduce agricultural waste.

The chemical characterization of natural products is often a complex task that demands powerful analytical techniques. Liquid chromatography with high-resolution tandem mass spectrometry (HRMS/MS) is often employed, yet it can face hard challenges when isomeric species are present, and reference standards are lacking. In such cases, the confidence level in compound identification can be significantly improved by the collection of orthogonal information on target analytes. In this work, 23 key compounds in Boswellia serrata extract (BSE), 12 of which correspond to boswellic acids (BAs) and 11 to triterpenoidic acid isomers, were identified by combining RPLC followed by serial UV and ESI(-)-FTMS and FTMS/MS detections with the evaluation of the reactivity towards C=C bond epoxidation with meta-chloroperoxybenzoic acid (m-CPBA), proposed as a fast chemical tool to gather information about C=C bond steric hindrance, a key structural feature of BAs and related compounds. The interpretation of UV spectra acquired after chromatographic separation corroborated the identification of the substitution patterns of enonic and dienic residues in ketoboswellic and dehydroboswellic acids. Moreover, MS/MS based on higher-energy collision-induced dissociation (HCD) unveiled new fragmentation pathways, providing important structural details on target analytes. The integrated approach developed during this study might pave the way for a deeper understanding of the BSE bioactive properties. Moreover, it can be considered an example of a more general strategy for the analysis of complex mixtures of natural compounds including also isomeric species.

Carvacrol and thymol are broad-spectrum natural antimicrobial agents. To reduce their volatility and improve their antimicrobial performance, synergistic systems were prepared loading the active molecules in zinc-modified clays. Montmorillonite (MMT) and zeolite (ZEO) were modified with zinc ions (ZnMMT and ZnZEO), with well-known antimicrobial properties, and then with carvacrol or thymol, reaching the 26 ± 3% and 33 ± 2% w/w of loading, respectively. The resulting hybrid materials were characterized by FT-IR, XPS, XRD, TGA, and GC-MS to evaluate carvacrol/thymol release in simulating food matrices. Antimicrobial assays carried out using spoiler and pathogenic bacterial strains showed that the antimicrobial activity of both thymol and carvacrol was largely preserved once they were loaded into Zn-modified clays. However, MMT hybrids showed an antibacterial activity significantly higher than ZEO hybrids at 50 mg/mL of thymol and carvacrol. For this reason, deeper antimicrobial evaluations were carried out only for ZnMMT composites. ZnMMT loaded with thymol or carvacrol produced inhibition zones against most of the target strains, also at 3.12 mg/mL, while the positive controls represented by the single molecule thymol or carvacrol were not active. The hybrid materials can be useful for applications in which the antimicrobial activity of natural molecules need to be displayed over time as requested for the control of microbial pathogens and spoilage bacteria in different applications, such as active packaging, biomaterials, and medical devices.

(1) Background: DA-Gelucire^® 50/13-based solid lipid nanoparticles (SLNs) administering the neurotransmitter dopamine (DA) and the antioxidant grape-seed-derived proanthocyanidins (grape seed extract, GSE) have been prepared by us in view of a possible application for Parkinson’s disease (PD) treatment. To develop powders constituted by such SLNs for nasal administration, herein, two different agents, namely sucrose and methyl-β-cyclodextrin (Me-β-CD), were evaluated as cryoprotectants. (2) Methods: SLNs were prepared following the melt homogenization method, and their physicochemical features were investigated by Raman spectroscopy, Scanning Electron Microscopy (SEM), atomic force microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS). (3) Results: SLN size and zeta potential values changed according to the type of cryoprotectant and the morphological features investigated by SEM showed that the SLN samples after lyophilization appear as folded sheets with rough surfaces. On the other hand, the AFM visualization of the SLNs showed that their morphology consists of round-shaped particles before and after freeze-drying. XPS showed that when sucrose or Me-β-CD were not detected on the surface (because they were not allocated on the surface or completely absent in the formulation), then a DA surfacing was observed. In vitro release studies in Simulated Nasal Fluid evidenced that DA release, but not the GSE one, occurred from all the cryoprotected formulations. Finally, sucrose increased the physical stability of SLNs better than Me-β-CD, whereas RPMI 2650 cell viability was unaffected by SLN-sucrose and slightly reduced by SLN-Me-β-CD. (4) Conclusions: Sucrose can be considered a promising excipient, eliciting cryoprotection of the investigated SLNs, leading to a powder nasal pharmaceutical dosage form suitable to be handled by PD patients.

Boswellia serrata Roxb. extract (BSE), rich in boswellic acids, is well known as a potent anti-inflammatory natural drug. However, due to its limited aqueous solubility, BSE inclusion into an appropriate carrier, capable of improving its release in the biological target, would be highly desirable. Starting with this requirement, new hybrid composites based on the inclusion of BSE in a lamellar solid layered double hydroxide (LDH), i.e., magnesium aluminum carbonate, were developed and characterized in the present work. The adopted LDH exhibited a layered crystal structure, comprising positively charged hydroxide layers and interlayers composed of carbonate anions and water molecules; thus, it was expected to embed negatively charged boswellic acids. In the present case, a calcination process was also adopted on the LDH to increase organic acid loading, based on the replacement of the original inorganic anions. An accurate investigation was carried out by TGA, PXRD, FT-IR/ATR, XPS, SEM, and LC-MS to ascertain the nature, interaction, and quantification of the active molecules of the vegetal extract loaded in the developed hybrid materials. As a result, the significant disruption of the original layered structure was observed in the LDH subjected to calcination (LDHc), and this material was able to include a higher amount of organic acids when its composite with BSE was prepared. However, in vitro tests on the composites’ bioactivity, expressed in terms of antimicrobial and anti-inflammatory activity, evidenced LDH–BSE as a better material compared to BSE and to LDHc–BSE, thus suggesting that, although the embedded organic acid amount was lower, they could be more available since they were not firmly bound to the clay. The composite was able to significantly decrease the number of viable pathogens such as Escherichia coli and Staphylococcus aureus, as well as the internalization of toxic active species into human cells imposing oxidative stress, in comparison to the BSE.