3D-printed scaffold composites for the stimuli-induced local delivery of bioactive adjuncts

Polysaccharide scaffolds have been successfully employed to reconstruct environments that sustain skin tissue regeneration after injuries. Three-dimensional (3D) advanced additive manufacturing technologies allow creating scaffolds with controlled and reproducible macro- and micro-structure that improve the quality of the restored tissue to favor spontaneous repair. However, when persistent inflammation occurs, the physiological tissue healing capacity is reduced, like in the presence of pathologies like diabetes, vascular diseases, chronic infection, and others. In these circumstances, the bioavailability of therapeutic adjuncts like the growth factors in addition to the standard treatments represents undoubtedly a promising strategy to accelerate the healing of skin lesions. Precisely designed polysaccharide scaffolds obtained by 3D printing represent a robust platform that can be further implemented with the controlled delivery of bioactive adjuncts. Human elastin-like polypeptides (HELPs) are stimuli-responsive biopolymers. Their structure allows the integration of domains endowed with biological functionality, making them attractive compounds to prepare composites with smart properties. In the present study, 3D-printed alginate and chitosan scaffolds were combined with the HELP components. The HELP biopolymer was fused to the epidermal growth factor (EGF) as the bioactive domain. Different constructs were prepared and the stimuli-responsive behavior as well as the biological activity were evaluated, suggesting that these smart bioactive composites are suitable to realize multifunctional dressings that sustain the local release of therapeutic adjuncts

Surface antibody changes protein corona both in human and mouse serum but not final opsonization and elimination of targeted polymeric nanoparticles

Background: Nanoparticles represent one of the most important innovations in the medical field. Among nanocarriers, polymeric nanoparticles (PNPs) attracted much attention due to their biodegradability, biocompatibility, and capacity to increase efficacy and safety of encapsulated drugs. Another important improvement in the use of nanoparticles as delivery systems is the conjugation of a targeting agent that enables the nanoparticles to accumulate in a specific tissue. Despite these advantages, the clinical translation of therapeutic approaches based on nanoparticles is prevented by their interactions with blood proteins. In fact, the so-formed protein corona (PC) drastically alters the biological identity of the particles. Adsorbed activated proteins of the complement cascade play a pivotal role in the clearance of nanoparticles, making them more easily recognized by macrophages, leading to their rapid elimination from the bloodstream and limiting their efficacy. Since the mouse is the most used preclinical model for human disease, this work compared human and mouse PC formed on untargeted PNPs (uPNPs) and targeted PNPs (tPNPs), paying particular attention to complement activation. Results: Mouse and human serum proteins adsorbed differently to PNPs. The differences in the binding of mouse complement proteins are minimal, whereas human complement components strongly distinguish the two particles. This is probably due to the human origin of the Fc portion of the antibody used as targeting agent on tPNPs. tPNPs and uPNPs mainly activate complement via the classical and alternative pathways, respectively, but this pattern did not affect their binding and internalization in macrophages and only a limited consumption of the activity of the human complement system was documented. Conclusions: The results clearly indicate the presence of complement proteins on PNPs surface but partially derived from an unspecific deposition rather than an effective complement activation. The presence of a targeting antibody favors the activation of the classical pathway, but its absence allows an increased activation of the alternative pathway. This results in similar opsonization of both PNPs and similar phagocytosis by macrophages, without an impairment of the activity of circulating complement system and, consequently, not enhancing the susceptibility to infection. Graphical abstract: [Figure not available: see fulltext.

Combined Used of Rheology and LF-NMR for the Characterization of PVP-Alginates Gels Containing Liposomes

10siPurpose: This paper is based on the characterization of the rheological and Low Field NMR (LF-NMR) properties of an interpenetrated hydrogel made up by poly(N-vinyl-2-pyrrolidone) and sodium alginate. The final aim is to use the hydrogel as a delivery matrix for liposomes, widely used tools in the drug delivery field. Methods: Rheology, LF-NMR, TEM, cryo-TEM, confocal laser scanning microscopy and release test were employed to characterize the interpenetrated hydrogel. Different theoretical approaches such as Flory, Chui, Scherer and Schurz theories were used to interpret the experimental results. Results: We found that the crosslinking mechanisms of the two polymers produced an anti-synergistic effect on the final mechanical properties of the interpenetrated hydrogel. Instead of creating a continuous network, alginate formed isolated, cross-linked, clusters embedded in a continuous network of poly(N-vinyl-2-pyrrolidone). Additionally, gel structure significantly influenced liposome deliverypartially_openopenGiulia Fanesi, Michela Abrami, Francesca Zecchin, Irina Giassi, Elena Dal Ferro, Anja Boisen, Gabriele Grassi, Paolo Bertoncin, Mario Grassi, Paolo MarizzaFanesi, Giulia; Abrami, Michela; Zecchin, Francesca; Giassi, Irina; DAL FERRO, Elena; Boisen, Anja; Grassi, Gabriele; Bertoncin, Paolo; Grassi, Mario; Marizza, Paol

Novel high yield and continuous process in manufacturing of nanoliposomes covered by polymeric thin layer

Liposomes constitute a class of prominent drug delivery systems due their cell-mimetic behaviour. Nowadays the most common techniques used for the production of liposomal delivery systems, such as Freeze-thawing, Thin film hydration, Ethanol injection, and Reverse phase evaporation, are all characterized by bulk discontinuous processes and low productivity. Moreover drastic conditions (such as low/high temperatures and pressures) make these techniques energetically onerous. In order to produce higher volumes of liposomal vectors, directly on nanometric size, overcoming the operating limits above discussed, a robust, simple, and easy-to-transfer technology was realized. In particular, a novel continuous bench scale apparatus was designed and developed, by exploiting microfluidics principles transposed on a millimeter scale, and coupling it with an ultrasound process used as intensification tool for vesicles homogenization. Moreover, the same innovative continuous method, based on microfluidic principles, was used to achieve wrapping of liposomes by chitosan (a natural biocompatible polymer) to overcome some typical drawbacks of liposomes, such as poor stability into biological fluids as well as in stocking conditions, and to manufacture stable shell-core nanostructures

Coating of Nanolipid Structures by a Novel Simil-Microfluidic Technique: Experimental and Theoretical Approaches

Nanolipid vesicular structures are ideal candidates for the controlled release of various ingredients, from vitamins for nutraceutical purposes to chemoterapic drugs. To improve their stability, permeability, and some specific surface properties, such as mucoadhesiveness, these structures can require a process of surface engineering. The interaction of lipid vesicles with oppositely charged polyelectrolytes seems to be an interesting solution, especially when the negatively charged liposomes are complexed with the cationic chitosan. In this work, a novel simil-microfluidic technique was used to produce both chitosan-coated vesicles and a vegan alternative composed of cholesterol-free liposomes coated by Guar Hydroxypropyltrimonium Chloride (Guar-HC). The combination between the experimental approach, based on experimental observations in terms of Z-potential, and size evolutions, and the theoretical approach, based on concepts of saturation, was the methodology applied to define the best polycation concentration to fairly cover (vegan or not) liposomes without aggregation. The smart production of coated nanolipid structures was confirmed by characterizations of morphology, mucoadhesiveness, and stability

Drought-induced dieback of Pinus nigra: a tale of hydraulic failure and carbon starvation

10siOngoing climate change is apparently increasing tree mortality rates, and understanding mechanisms of drought-induced tree decline can improve mortality projections. Differential drought impact on conspecific individuals within a population has been reported, but no clear mechanistic explanation for this pattern has emerged. Following a severe drought (summer 2012), we monitored over a 3-year period healthy (H) and declining (D) Pinus nigra trees co-occurring in a karstic woodland to highlight eventual individual-specific physiological differences underlying differential canopy dieback. We investigated differences in water and carbon metabolism, and xylem anatomy as a function of crown health status, as well as eventual genotypic basis of contrasting drought responses. H and D trees exploited the same water pools and relied on similar hydraulic strategies to cope with drought stress. Genetic analyses did not highlight differences between groups in terms of geographical provenance. Hydraulic and anatomical analyses showed conflicting results. The hydraulic tracheid diameter and theoretical hydraulic conductivity were similar, but D trees were characterized by lower water transport efficiency, greater vulnerability to xylem conduit implosion and reduced carbohydrate stores. Our results suggest that extreme drought events can have different impacts on conspecific individuals, with differential vulnerability to xylem embolism likely playing a major role in setting the fate of trees under climate change.openopenSavi, Tadeja; Casolo, Valentino; Dal Borgo, Anna; Rosner, Sabine; Torboli, Valentina; Stenni, Barbara; Bertoncin, Paolo; Martellos, Stefano; Pallavicini, Alberto; Nardini, AndreaSavi, Tadeja; Casolo, Valentino; Dal Borgo, Anna; Rosner, Sabine; Torboli, Valentina; Stenni, Barbara; Bertoncin, Paolo; Martellos, Stefano; Pallavicini, Alberto; Nardini, Andre

Fluorescent Imprinted Nanoparticles for the Effective Monitoring of Irinotecan in Human Plasma

Fluorescent, imprinted nanosized polymers for the detection of irinotecan have been synthesised using a napthalimide polymerisable derivative (2-allyl-6-[2-(aminoethyl)-amino] napthalimide) as functional monomer. The imprinted polymers contain ethylene glycol dimethacrylate (EGDMA) as a cross-linker and were prepared by high dilution radical polymerisation in dimethylsulphoxide (DMSO). The material was able to rebind irinotecan up to 18 nmol/mg with good specificity. Fluorescence emission at 525 nm (excitation at 448 nm) was quenched by increasing concentrations of irinotecan via a static mechanism and also in analytically useful environments as mixtures of human plasma and organic solvents. This allowed the direct detection of irinotecan (in the 10 nM-30 \ub5M range) in human plasma treated with acetonitrile; the limit of detection (LOD) was 9.4 nM, with within-run variability of 10% and day-to-day variability of 13%

micronutrients encapsulation in enhanced nanoliposomal carriers by a novel preparative technology

Micronutrients administration by liposomal vectors is a growing strategy in fortification processes of staple and complementary foods to fight malnutrition and micronutrient deficiencies and related pathologies

Simil-Microfluidic Nanotechnology in Manufacturing of Liposomes as Hydrophobic Antioxidants Skin Release Systems

Novel nanotechnologies represent the most attractive and innovative tools to date exploited by cosmetic companies to improve the effectiveness of their formulations. In this context, nanoliposomes have had a great impact in topical preparations and dermocosmetics, allowing the transcutaneous penetration and absorption of several active ingredients and improving the stability of sensitive molecules. Despite the recent boom of this class of delivery systems, their industrial production is still limited by the lack of easily scalable production techniques. In this work, nanoliposomes for the topical administration of vitamin D3, K2, E, and curcumin, molecules with high antioxidant and skin curative properties but unstable and poorly absorbable, were produced through a novel simil-microfluidic technique. The developed high-yield semi continuous method is proposed as an alternative to face the problems linked with low productive conventional methods in order to produce antioxidant formulations with improved features. The novel technique has allowed to obtain a massive production of stable antioxidant vesicles of an 84–145 nm size range, negatively charged, and characterized by high loads and encapsulation efficiencies. The obtained products as well as the developed high-performance technology make the achieved formulations very interesting for potential topical applications in the cosmetics/cosmeceutical field