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Fmoc-diphenylalanine as a suitable building block for the preparation of hybrid materials and their potential applications
No full textDue to its capability to self-assemble in self-supporting hydrogels (HG) under physiological conditions, Fmoc-FF is one of the most studied ultra-short peptide. The structural properties of the resulting hydrogel (mechanical rigidity, entanglement of the fibrillary network, and the thickness of the fibers) strictly depend on the experimental conditions used during the preparation. In the past few years, a broad range of applications in different fields, such as biomedical and industrial fields, have been proposed. However, the research on novel materials with enhanced mechanical properties, stability, and biocompatibility has brought about the development of novel Fmoc-FF-based hybrid systems, in which the ultra-short hydrogelator is combined with others entities such as polysaccharides, polymers, peptides, or organic molecules. The structural features and the potential applications of these novel hybrid materials, with particular attention to tissue engineering, drug delivery, and catalysis, are described here. The aim is to give the readers a tool to design new hybrid nanomaterials based on the Fmoc-FF dipeptide hydrogelator, with appropriate properties for specific applications
Peptide-based hydrogels as delivery systems for doxorubicin
No full textHydrogels (HGs) and nanogels (NGs) have been recently identified as innovative supramolecular materials for many applications in biomedical field such as in tissue engineering, optoelectronic, and local delivery of active pharmaceutical ingredients (APIs). Due to their in vivo biocompatibility, synthetic accessibility, low cost, and tunability, peptides have been used as suitable building blocks for preparation of HGs and NGs formulations. Peptide HGs have shown an outstanding potential to deliver small drugs, protein therapeutics, or diagnostic probes, maintaining the efficacy of their loaded molecules, preventing degradation phenomena, and responding to external physicochemical stimuli. In this review, we discuss the possible use of peptide-based HGs and NGs as vehicles for the delivery of the anticancer drug doxorubicin (Dox). This anthracycline is clinically used for leukemia, stomach, lung, ovarian, breast, and bladder cancer therapy. The loading of Dox into supramolecular systems (liposomes, micelles, hydrogels, and nanogels) allows reducing its cardiotoxicity. According to a primary sequence classification of the constituent peptide, doxorubicin-loaded systems are here classified in short and ultra-short peptide-based HGs, RGD, or RADA-peptide-based HGs and peptide-based NGs
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No full textStable formulations of peptide-based nanogels
No full textRecently, nanogels have been identified as innovative formulations for enlarging the application of hydrogels (HGs) in the area of drug delivery or in diagnostic imaging. Nanogels are HGs-based aggregates with sizes in the range of nanometers and formulated in order to obtain injectable preparations. Regardless of the advantages offered by peptides in a hydrogel preparation, until now, only a few examples of peptide-based nanogels (PBNs) have been developed. Here, we describe the preparation of stable PBNs based on Fmoc-Phe-Phe-OH using three different methods, namely water/oil emulsion (W/O), top-down, and nanogelling in water. The effect of the hydrophilic–lipophilic balance (HLB) in the formulation was also evaluated in terms of size and stability. The resulting nanogels were found to encapsulate the anticancer drug doxorubicin, chosen as the model drug, with a drug loading comparable with those of the liposomes
Forward precision medicine: Micelles for active targeting driven by peptides
Full text linkPrecision medicine is based on innovative administration methods of active principles. Drug delivery on tissue of interest allows improving the therapeutic index and reducing the side effects. Active targeting by means of drug-encapsulated micelles decorated with targeting bioactive moieties represents a new frontier. Between the bioactive moieties, peptides, for their versatility, easy synthesis and immunogenicity, can be selected to direct a drug toward a considerable number of molecular targets overexpressed on both cancer vasculature and cancer cells. Moreover, short peptide sequences can facilitate cellular intake. This review focuses on micelles achieved by self-assembling or mixing peptide-grafted surfactants or peptide-decorated amphiphilic copolymers. Nanovectors loaded with hydrophobic or hydrophilic cytotoxic drugs or with gene silence sequences and externally functionalized with natural or synthetic peptides are described based on their formulation and in vitro and in vivo behaviors
Ready-to-eat roasted suckling piglet (Porcheddu): An innovative process for a sardinian traditional dish
No full textRoasted piglet (Porcheddu) is one of the most appreciated traditional Sardinian dishes obtained from suckling animals slaughtered at 8-12 kg of body weight (BW). The traditional cooking method is time-consuming; this dish is eaten only when there is enough time for its preparation (cooking time of about 2 h). The Porcheddu is appreciated by both local and foreign consumers and there is also an increasing interest, for this traditional dish, by extra regional consumers and markets. Actually, since the occurrence of African swine fever (ASF), the trade of pigs and pig meat products is not permitted from Sardinia. The Council Directive 2002/99/EC provided a derogation for states member to authorize the production, processing and distribution of products of animal origin when a Heat treatment at a minimum temperature of 80°C, which must be reached throughout the meat is applied. The overall framework of this study was to evaluate an innovative process to obtain a traditional dish the Porcheddu suitable to achieve extra-regional markets and meet the demand of modern consumers and to assess the effect of carcass weight on the processing yield of suckling piglets, thermally treated, to obtain a ready-to-eat roast dish
Amyloid-Like Aggregation in Diseases and Biomaterials: Osmosis of Structural Information
No full textThe discovery that the polypeptide chain has a remarkable and intrinsic propensity to form amyloid-like aggregates endowed with an extraordinary stability is one of the most relevant breakthroughs of the last decades in both protein/peptide chemistry and structural biology. This observation has fundamental implications, as the formation of these assemblies is systematically associated with the insurgence of severe neurodegenerative diseases. Although the ability of proteins to form aggregates rich in cross-β structure has been highlighted by recent studies of structural biology, the determination of the underlying atomic models has required immense efforts and inventiveness. Interestingly, the progressive molecular and structural characterization of these assemblies has opened new perspectives in apparently unrelated fields. Indeed, the self-assembling through the cross-β structure has been exploited to generate innovative biomaterials endowed with promising mechanical and spectroscopic properties. Therefore, this structural motif has become the fil rouge connecting these diversified research areas. In the present review, we report a chronological recapitulation, also performing a survey of the structural content of the Protein Data Bank, of the milestones achieved over the years in the characterization of cross-β assemblies involved in the insurgence of neurodegenerative diseases. A particular emphasis is given to the very recent successful elucidation of amyloid-like aggregates characterized by remarkable molecular and structural complexities. We also review the state of the art of the structural characterization of cross-β based biomaterials by highlighting the benefits of the osmosis of information between these two research areas. Finally, we underline the new promising perspectives that recent successful characterizations of disease-related amyloid-like assemblies can open in the biomaterial field
Peptide-based building blocks as structural elements for supramolecular Gd-containing MRI contrast agents
No full textMagnetic resonance imaging (MRI) is one of the most important clinic diagnostic tool
used to obtain high‐quality body images. The administration of low‐molecular‐weight
Gd complex–based MRI contrast agents (CAs) permits to increase the 1H relaxation
rate of nearby water molecules, thus modulating signal intensity and contrast
enhancement. Even if highly accurate, MRI modality suffers from its low sensitivity.
Moreover, low‐molecular‐weight CAs rapidly equilibrate between the intravascular
and extravascular spaces after their administration. In order to improve their sensitivity
and limit the extravasation phenomenon, several macromolecular and supramolecular
multimeric gadolinium complexes (dendrimers, polymers, carbon nanostructures,
micelles, and liposomes) have been designed until now. Because of their biocompatibility,
low immunogenicity, low cost, and easy synthetic modification, peptides are
attractive building blocks for the fabbrication of novel materials for biomedical
applications. We report on the state of the art of supramolecular CAs obtained by
self‐assembly of three different classes of building blocks containing a peptide
sequence, a gadolinium complex, and, if necessary, a third functional portion achieving
the organization process
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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