96 research outputs found
Water-soluble Polyester-based Amino Acids-modified Dendrimers loaded with Ursolic and Oleanolic Acids as promising Prodrugs suitable for Intravenous Administration
No full textDendrimers, macromolecules characterized by high controlled size, shape and architecture, presence of inner cavities able to accommodate small molecules and many peripheral functional groups, are of eminent interest for biomedical applications, including gene transfection, tissue engineering, imaging, drug delivery.[1] The well-known pharmacological activities of Ursolic and Oleanolic acids[2] are limited by low water solubility, non-specific cells distribution, poor bioavailability and pharmacokinetics. Thus, the research for new formulations of UA and OA that overcome such drawbacks is very extensive. The strategy most applied concerns the use of carriers, such as liposomes or PAMAM dendrimers which are among the most investigated vectors because endowed with very efficient transfection and delivery activities but also with remarkable cytotoxicity. In this work we described the physical incorporation of the two triterpene acids extracted from Salvia Corrugata inside amino acids-modified polyester-based dendrimers.[3,4] IR, NMR, zeta potential, mean size of particles and buffer capacity of prepared materials were reported.
Figure 1. An eye-catching representation of the prepared complexes
The achieved water soluble complexes harmonize a polycationic character and a buffer capacity which presuppose efficient cells penetration and increased residence time with a biodegradable scaffold thus appearing as a promising team of new non-toxic prodrugs for safe intravenous administration of Ursolic and Oleanolic acids (Figure 1).
[1] S. N. Goonewardena, J. D. Kratz, H. Zong, A. M. Desai, S. Tang, S. Emery, J. R. Jr. Baker, B. Huang, Design considerations for PAMAM dendrimer therapeutics, Biorg. Med. Chem. lett., 23, 2872 (2013).
[2] J. Liu, Pharmacology of oleanolic acid and ursolic acid, J. Ethnopharmacol., 49, 57 (1995).
[3] S. Alfei, S. Castellaro, Synthesis and Characterization of Polyester-Based Dendrimers Containing Peripheral Arginine or Mixed Amino Acids as Potential Vectors for Gene and Drug Delivery, Macromol. Res., DOI 10.1007/s13233-017-5160-3 (2017).
[4] S. Alfei, S. Castellaro, G. B. Taptue, Synthesis and NMR characterization of dendrimers based on 2, 2-bis-(hydroxymethyl)-propanoic acid (bis-HMPA) containing peripheral amino acid residues for gene transfection, Org. Commun., 10, 144 (2017)
How five different isoforms of N,N,N-Tris(tert-butoxycarbonyl)-L-arginine whose reactivity in esterification reactions was subsequently investigated were obtained
No full textL-arginine, nowadays, is more and more used to functionalize scaffolds for producing delivery systems with high transfection activity and low toxicity. For these purposes it is better to be protected to basic nitrogen atoms. A well known protective residue is tert-butoxycarbonyl group (BOC) and three protocols of BOC-protection selected by us assured that the widely cited (E)-αN,ωN,ω’N-tris(tert-butyloxycarbonyl)-L-arginine would be the only product obtainable. Surprisingly we achieved also other four isoforms (Figure 1) [1]. With the first tested procedure [2] αN,ωN,ω’N-Tris(tert-butyloxycarbonyl)-L-arginine was never obtained. The second one [3] provided the goal compound but in mixture with the Z rotamer while the third protocol [4] led to a single very pure isoform in high yield but with an unreported symmetrical structure. Since BOC protection is transient this discovery would seem of poor interest but investigations about the behavior of each one of the isoforms obtained in esterification reactions, whose results have been described in details in another work by us presented in this context, shown that their reactivity depends on their structure. With this work we reported a thorough description of this unexpected results and the meticulous NMR investigation performed with particular care for double bonds geometry and position which confirmed the structures.
References: 1. S. Alfei, S. Castellaro, Res. Chem. Intermediat. 44, 1811 (2018) DOI: 10.1007/s11164-017-3199-6. 2. H. Konno, K. Kubo, H. Makabe, E. Toshiro, N. Hinoda, K. Nosakaa, K: Akaji, Tetrahedron 63, 9502 (2007) doi:10.1016/j.tet.2007.06.082.3. J. Izdebski, T. Gers, D. Kunce, P. Markovsky, J. Pept. Sci. 11, 60 (2005) doi: 10.1002/psc.585.4. M. A. Jones, A. D. Hislop, J. S. Snaith, Org. Biomol. Chem. 4, 3769 (2006) doi: 10.1039/b611170
Synthesized Triphenyl-phosphonium-Based Nanovesicles Induce Apoptotic Death in MDR Neuroblastoma Cells, While Exert Low Toxicity Towards Primary Cell Cultures
No full textNeuroblastoma (NB) is a children malignant tumour having an incidence of about 15,000 new cases per year worldwide and a survival rate < 50%, due to therapy-induced secondary tumorigenesis and emerging multidrug-resistant (MDR) NB cells, in the high-risk (HR-NB) forms. Recently, we were testing in vitro the effects of triphenyl phosphonium (TPP)-based bola amphiphilic nanovesicles, towards various drug-sensitive and MDR cancer cell lines1,2,3. Such vesicles self-form by dispersing in water the sterically hindered quaternary phosphonium salt, 1,1-(1,12-dodecanediyl)-bis-[1,1,1]-triphenyl phosphonium di-bromide (BPPB). It was obtained as hygroscopic low-melting white foam by reacting 1,12-dibromo-dodecane with triphenylphosphine in ethanol (EtOH), at reflux for 48 h4 according to Scheme 1.
Scheme 1. Synthetic route to achieve BPPB.
ATR-FTIR, NMR, UV, FIA-MS (ESI) and elemental analysis confirmed its structure, while DLS analyses showed spherical vesicles of 45 nm in solution, having positive ζ of +18 mV4. Here, BPPB vesicles (BPPBVs) were tested in vitro against both drug-sensitive HTLA 230 human stage-IV and MDR HTLA ER, HR-NB cells, observing IC50 values of 0.4-0.9 and 1.20-1.35 μM, respectively. We have demonstrated that BPPBVs kill both cell populations by an apoptotic mechanism without necrosis, sustained by reactive oxygen species (ROS) overproduction. As a novelty, by an analytical approach, a correlation study was carried out to verify if BPPBVs cytotoxic effects could depend on their concentrations, exposure times and/or ROS overproduction and if ROS increase could depend on BPPBV concentrations and/or time exposure. To better support the potential clinical development of BPPBVs as a new therapeutic option to treat MDR HR-NB, their effects were tested on primary astrocytes and neurons, observing appreciable and good tolerability in neurons and astrocytes respectively, allowing selectivity index values up to 23.7. These in vitro results associated to the low haemolytic activity of BPPB, previously reported1,2,3,4 pave the way for future in vivo investigations and, upon confirmation, for the possible development of BPPB as a novel therapeutic strategy to treat MDR HR-NB.
References:
[1] S. Alfei, B. Marengo, et al. Nanomaterials 2024, 14, 1505. https://doi.org/10.3390/nano14181505.
[2] S. Alfei, B. Marengo, et al. Int. J. Mol. Sci. 2024, 25, 10071. https://doi.org/10.3390/ijms251810071.
[3] S. Alfei, B. Marengo, et al. Int. J. Mol. Sci. 2025, 26, 3227. https://doi.org/10.3390/ijms26073227
[4] S. Alfei, A.M. Schito, et al. Nanomaterials 2024, 14, 1351. https://doi.org/10.3390/nano1416135
Triphenyl-phosphonium (TPP)-Based Nanovesicles Induce ROS Increase, Eradicate MDR Melanoma and Neuroblastoma Cells, While Exerting Low Toxicity Towards Red Blood Cells (RBCs), Human Not Tumorigenic Cells and Mice Primary Cell Cultures
No full textNeuroblastoma (NB) and metastatic cutaneous melanoma (MCM) are a severe children malignant solid tumour and the most aggressive skin cancer existing respectively, with low survival rate and poor prognosis, due to therapy-induced secondary tumorigenesis and emerging multidrug-resistance (MDR). Recently, we obtained in water self-forming TPP-based bola amphiphilic nanovesicles (BANs), deriving by the quaternary phosphonium salt, 1,1-(1,12-dodecanediyl)-bis-[1,1,1]-triphenyl phosphonium di-bromide (BPPB), synthesized by reacting 1,12-dibromo-dodecane with triphenylphosphine in ethanol, refluxing for 48 h (Alfei et al. 2024a).
ATR-FTIR, NMR, UV, FIA-MS (ESI) and elemental analysis confirmed its structure. DLS analyses showed spherical vesicles of 45 nm, having positive ζ =f +18 mV (Alfei et al. 2024a). Extensively employed as drug delivery systems, no report existed on the per se cytotoxic activity of any BAN towards any cancer cell line, before our studies. Notably, BANs provided excellent outcomes, when tested on drug-sensitive and MDR MCM and HR-NB cells, as well as on non-tumorigenic human cells, mice primary cells and RBCs to assess their cytotoxicity and their biocompatibility, respectively (Alfei et al. 2024b; Alfei et al. 2024c; Alfei et al. 2025a; Alfei et al. 2025b). Specifically, experimented against PLX-sensitive BRAF mutants MCM cells (MeOV and MeTRAV), BANs showed a ROS-dependent cytotoxicity, displaying nanomolar IC50 of 49 (MeOV) and 171 nM (MeTRAV) and inducing a ROS production 16-fold higher than in the control (72h treatments). Conversely, BANs elicited low cytotoxicity against various non-tumorigenic human cells and RBCs, allowing selectivity index (SI) values of 5-19 (MRC-5, 72h), 8-11 (HepG2, 24h) and 87-229 (RBCs, 72h). Regardless of the acquired resistance, PLX-resistant MCM cells exposed to BANs provided nanomolar IC50 of 88 nM (PLX-R-MeOV, 48h) and 81 nM (PLX-R-MeTRAV, 72h), as well. ROS increase was 25- and 15-fold higher than in the control (MeOV and MeTRAV respectively), after 72h exposure. Anyway, a ROS-dependent cytotoxicity was established only in MeTRAV for 72h treatments. Forecasting a future development of BANs as topical device to treat skin MCM lesions, its biocompatibility was essayed on human keratinocytes (HaCaT), observing SI values up to 12. Furthermore, RBCs were exposed to BANs, high HC50 values were observed allowing SI = 16–173 and 4–192 (PLX-R MeOV and MeTRAV, respectively). Recently, BANs were tested against drug-sensitive HTLA 230 human stage-IV and MDR HTLA ER high-risk (HR)-NB cells, observing apoptotic death at IC50 of 0.4-0.9 and 1.20-1.35 μM, respectively, sustained by moderate ROS overproduction (ROS levels 5-6-fold higher than in the control). Here, by an analytical approach, a correlation study was carried out to verify if BANs cytotoxicity depended on their concentrations, exposure times and/or ROS overproduction and if ROS increase depended on BANs concentrations and/or time exposure. To better support the potential clinical development of BANs as a new therapeutic option to treat MDR HR-NB, their effects were tested on primary astrocytes and neurons. Appreciable and good tolerability was observed in neurons and astrocytes respectively, allowing SI values up to 24. Collectively, these in vitro results pave the way for future in vivo investigations using BANs and for the possible development of BANs as a novel therapeutic strategy to treat MDR MCM and HR-NB.
REFERENCE
Alfei, S. et al. 2024a. Synthesized Bis-Triphenyl Phosphonium-Based Nano Vesicles Have Potent and Selective Antibacterial Effects on Several Clinically Relevant Superbugs. Nanomaterials 14(16), p. 1351. doi: 10.3390/nano14161351.
Alfei, S. et al. 2024b. The Remarkable and Selective In Vitro Cytotoxicity of Synthesized Bola-Amphiphilic Nanovesicles on Etoposide-Sensitive and -Resistant Neuroblastoma Cells. Nanomaterials 14(18), p. 1505. doi: 10.3390/nano14181505.
Alfei, S. et al. 2025a. TPP-Based Nanovesicles Kill MDR Neuroblastoma Cells and Induce Moderate ROS Increase, While Exert Low Toxicity To-wards Primary Cell Cultures: an in Vitro Study . IJMS 26(16), p. 4991. doi: https://doi.org/10.3390/ijms26114991.
Alfei, S., Torazza, C., Bacchetti, F., Signorello, M.G., Passalacqua, M., Domenicotti, C. and Marengo, B. 2025b. Tri-Phenyl-Phosphonium-Based Nano Vesicles: A New In Vitro Nanomolar-Active Weapon to Eradicate PLX-Resistant Melanoma Cells. International Journal of Molecular Sciences 26(7), p. 3227. doi: 10.3390/ijms26073227.
Alfei, S., Zuccari, G., Athanassopoulos, C.M., Domenicotti, C. and Marengo, B. 2024c. Strongly ROS-Correlated, Time-Dependent, and Selective Antiproliferative Effects of Synthesized Nano Vesicles on BRAF Mutant Melanoma Cells and Their Hyaluronic Acid-Based Hydrogel Formulation. International Journal of Molecular Sciences 25(18), p. 10071. doi: 10.3390/ijms251810071
Cationic Materials for Gene Therapy: A Look Back to the Birth and Development of 2,2-Bis-(hydroxymethyl)Propanoic Acid-Based Dendrimer Scaffolds
No full textGene therapy is extensively studied as a realistic and promising therapeutic approach for treating inherited and acquired diseases by repairing defective genes through introducing (transfection) the “healthy” genetic material in the diseased cells. To succeed, the proper DNA or RNA fragments need efficient vectors, and viruses are endowed with excellent transfection efficiency and have been extensively exploited. Due to several drawbacks related to their use, nonviral cationic materials, including lipidic, polymeric, and dendrimer vectors capable of electrostatically interacting with anionic phosphate groups of genetic material, represent appealing alternative options to viral carriers. Particularly, dendrimers are highly branched, nanosized synthetic polymers characterized by a globular structure, low polydispersity index, presence of internal cavities, and a large number of peripheral functional groups exploitable to bind cationic moieties. Dendrimers are successful in several biomedical applications and are currently extensively studied for nonviral gene delivery. Among dendrimers, those derived by 2,2-bis(hydroxymethyl)propanoic acid (b-HMPA), having, unlike PAMAMs, a neutral polyester-based scaffold, could be particularly good-looking due to their degradability in vivo. Here, an overview of gene therapy, its objectives and challenges, and the main cationic materials studied for transporting and delivering genetic materials have been reported. Subsequently, due to their high potential for application in vivo, we have focused on the biodegradable dendrimer scaffolds, telling the history of the birth and development of b-HMPA-derived dendrimers. Finally, thanks to a personal experience in the synthesis of b-HMPA-based dendrimers, our contribution to this field has been described. In particular, we have enriched this work by reporting about the b-HMPA-based derivatives peripherally functionalized with amino acids prepared by us in recent years, thus rendering this paper original and different from the existing reviews
A NANOSPHERICAL DENDRIMERIC GALLATE ESTER FOR LONG TERM PRESERVATION OF ESSENTIAL OILS: AN INTEGRATED CHEMOMETRIC ASSISTED FT-IR STUDY
No full textEssential oils (EOs) are hydrophobic concentrated liquids from plants made of volatile chemical compounds. EOs are very popular in the food, cosmetic and pharmaceutical industry as aromas, fragrances and alternative therapeutic devices [1, 2]. EOs are susceptible to degradation reactions, especially of oxidative type, triggered by temperature, light and oxygen availability. A loss of quality and alterations of sensory and pharmacological properties may occur, causing the production of smelly or even harmful compounds, responsible for allergic reactions and skin irritation [3-5]. For preventing and delaying EOs’ spoilage, synthetic preservatives as 2,6-bis(1,1-dimetiletil)-4-metilphenol (BHT) or t-butil-4-hydrohyanisole (BHA) are commonly adopted; but, in addition to a limited efficiency due mainly to poor solubility in oils, they may cause health diseases [6]. Natural polyphenols as gallic acid (GA) are nowadays proposed as safer alternatives, but their efficiency is limited by their low compatibility with hydrophobic material again, or by the occurrence of probable side reactions with oils constituents. Recently, a hydrophobic and biodegradable GA-enriched dendrimer (GAD) (Fig. 1.a) characterised by a nanospherical morphology (Fig. 1.b) and endowed with a remarkable antioxidant activity was synthetized [7]. Further studies currently being completed, have shown that GAD, with respect to free GA, possesses also more efficient antibacterial properties against several antibiotics-resistant G+ strains, inhibits platelet aggregation and ROS accumulation thus representing an excellent alternative to conventional drugs to combat infections and thrombus formation [8]. In this study, based on integrated results obtained from the due investigations, GAD is advised also as an innovative and semi-synthetic preservative additive.
a)
b)
Figure 1. Intuitive representation of GA-enriched dendrimer (GAD) structure (a); SEM images of GAD spherical nanoparticles (b). Scale bars represent 300 nm.
In this regard, GAD proved a much more efficient preservative power than free GA and, unlike GA, it never acts as a pro-oxidant. Besides classic oxidation indexes, the desired information was obtained by FT-IR spectroscopy assisted by multivariate analysis (MVA). For further confirmation of the so obtained results, interpretations of FT-IR data by considering the area of some selected informative bands and iodometric titrations to determine the hydro peroxide value (PV) were also performed [9].
References
[1] Yamamoto S., SOFW J., 2008, 134, 8.
[2] Jiang Y., Wu N., Fu Y.-J., Wang W., Luo M., Zhao C.-J., Zu Y.-G., and Liu Y.-L., Environ. Toxicol. Pharmacol., 2011, 32, 63.
[3] Hagvall L., Skold M., Brared-Christensson J., Borje A., and Karlberg A.-T., Contact Dermatitis, 2008, 59, 143.
[4] Skold M., Hagvall L., and Karlberg A.-T., Contact Dermatitis, 2008, 58, 9.
[5] Brared-Christensson J., Matura M., Gruvberger B., Bruze M., and Karlberg A.-T., Contact Dermatitis, 2010, 62, 32.
[6] Hirose M., Takesada Y., Tanaka H., Tamano S., Kato T., and Shirai T., Carcinogenesis, 1998, 19, 207.
[7] Alfei S., Catena S., and Turrini F., Drug Deliv. Trans. Res., under review.
[8] Alfei S., Signorello M. A., Schito A., Catena S., and Turrini F., results not yet published
[9] Alfei S., Oliveri P., and Malegori C., New J. Chem., under review
Inerbimento, tanti benefici per l'ambiente e gli alberi
No full textSpeciale gestione invernale dell'olivet
Nanostructured styrenic copolymers containing glucopyranosyl residues and their functionalization
No full textSugar-based co-polymers with saccharidic units in stable cyclic form and nanometric morphologies stabilized through crosslinking, adaptable through specific functionalizations to biochemical interaction studies with copper-containing amine oxidases, were synthesized from appropriate monomers and macromonomers. The most promising nanospherical co-polymer obtained, containing b-D-glucopyranosidic units, was employed in functionalization reactions with the help of model molecules, achieving useful transformations mainly at the 6-position and to a minor extent at the 2-position of the saccharidic system
N,N,N-Tris(tert-butoxycarbonyl)-L-arginine: five isoforms whose obtainment depends on procedure and a scrupulous NMR confirmation of their structures.
No full textL-arginine is often covalently linked to delivery systems for increasing their transfection activity and reducing toxicity and its basic nitrogen atoms need protection for example with tert-butoxycarbonyl group. Following three reported protocols which assured the goal of obtaining the widely cited αN,ωN,ω’N-tris(tert-butyloxycarbonyl)-L-arginine, surprisingly we achieved also other four isoforms (Figure 1). With the first selected procedure [1] αN,ωN,ω’N-Tris(tert-butyloxycarbonyl)-L-arginine was never obtained. The second one [2] provided the desired compound but as a mixture of geometric isomers E/Z while the third [3] protocol led to a single very pure isoform in high yield but with an unreported symmetrical structure. Since BOC protection is transient this discovery would seem of poor interest but results obtained from following investigations about the behavior of each one of the isoforms obtained in the esterification reactions of our interest shown that their reactivity depends on their structure. With this work we reported a detailed description of this unexpected results and the NMR investigation performed with particular care for double bonds geometry and position which confirmed the structures.
[1] H. Konno, K. Kubo, H. Makabe, E. Toshiro, N. Hinoda, K. Nosakaa, K: Akaji, Tetrahedron 63, 9502 (2007) doi:10.1016/j.tet.2007.06.082
[2] J. Izdebski, T. Gers, D. Kunce, P. Markovsky, J. Pept. Sci. 11, 60 (2005) doi: 10.1002/psc.585
[3] M. A. Jones, A. D. Hislop, J. S. Snaith, Org. Biomol. Chem. 4, 3769 (2006) doi: 10.1039/b611170
Recommendations to Synthetize Old and New β-Lactamases Inhibitors: A Review to Encourage Further Production
No full textThe increasing emergence of bacteria producing β-lactamases enzymes (BLEs), able to inactivate the available β-lactam antibiotics (BLAs), causing the hydrolytic opening of their β-lactam ring, is one of the global major warnings. According to Ambler classification, BLEs are grouped in serine-BLEs (SBLEs) of class A, C, and D, and metal-BLEs (MBLEs) of class B. A current strategy to restore no longer functioning BLAs consists of associating them to β-lactamase enzymes inhibitors (BLEsIs), which, interacting with BLEs, prevent them hydrolyzing to the associated antibiotic. Worryingly, the inhibitors that are clinically approved are very few and inhibit only most of class A and C SBLEs, leaving several class D and all MBLEs of class B untouched. Numerous non-clinically approved new molecules are in development, which have shown broad and ultra-broad spectrum of action, some of them also being active on the New Delhi metal-β-lactamase-1 (NDM-1), which can hydrolyze all available BLAs except for aztreonam. To not duplicate the existing review concerning this topic, we have herein examined BLEsIs by a chemistry approach. To this end, we have reviewed both the long-established synthesis adopted to prepare the old BLEsIs, those proposed to achieve the BLEsIs that are newly approved, and those recently reported to prepare the most relevant molecules yet in development, which have shown high potency, providing for each synthesis the related reaction scheme
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