The Panama microplate, island studies and relictual species of Melipona (Melikerria) (Hymenoptera: Apidae: Meliponini)

The endemic stingless honey-making bee Melipona (Melikerria) insularissp.n. on Coiba and Rancheria Islands in Pacific Panama is described, together with the proposed sister species, M. ambigua sp.n. from northeast Colombia. The Coiba Island group and Panama mainland were surveyed, yielding one meliponine endemic (M. insularissp.n.) and six meliponine genera and species. The poor Coiba fauna of amphibians and birds corresponds to the poor social bee fauna and suggests habitat barriers generally precluded recolonization from the mainland during glacial periods. Many animals became extinct, yet some remain as relicts. Melipona insularissp.n. was isolated on accreted terranes of Coiba rainforest in the Panama microplate. Morphology suggests that M. insularissp.n. is not a direct descendant of the San Blas-E. Panama endemic Melikerria, M. triplaridis. A phylogenetic hypothesis corroborates disjunct distributions. Rainforest endemics such as Peltogyne purpurea (Fabaceae) and Ptilotrigona occidentalis (Apidae, Meliponini) also occur as relictual, disjunct populations in Central and South America. These may have been isolated before accelerated biotic exchange began 2.4 Ma. Our work supports the geological findings of both a volcanic arc and the San Blas massif providing a substantial bridge for Melikerria from Colombia and Panama in Eocene to Miocene times. We suggest there have been taxon cycles permitting recolonization during glaciations, whereby colonies of M. insularissp.n. were able to recolonize Rancheria, a 250 ha island, 2 km from Coiba. However, rafting colonies nesting in trees, carried on vegetation mats, may have produced founding populations of Melipona in Central America and on oceanic islands such as Coiba.

Multi-Walled Carbon Nanotubes and Poly(lactic acid) Nanocomposite Fibrous Membranes Prepared by Solution Blow Spinning

Nanocomposite fibers based on multi-walled carbon nanotubes (MWCNT) and poly(lactic acid) (PLA) were prepared by solution blow spinning (SBS). Fiber morphology was characterized by scanning electron microscopy (SEM) and optical microscopy (OM). Electrical, thermal, surface and crystalline properties of the spun fibers were evaluated, respectively, by conductivity measurements (4-point probe), thermogravimetric analyses (TGA), differential scanning calorimetry (DSC), contact angle and X-ray diffraction (XRD). OM analysis of the spun mats showed a poor dispersion of MWCNT in the matrix, however dispersion in solution was increased during spinning where droplets of PLA in solution loaded with MWCNT were pulled by the pressure drop at the nozzle, producing PLA fibers filled with MWCNT. Good electrical conductivity and hydrophobicity can be achieved at low carbon nanotube contents. When only 1 wt% MWCNT was added to low-crystalline PLA, surface conductivity of the composites increased from 5 x 10(-8) to 0.46 S/cm. Addition of MWCNT can slightly influence the degree of crystallinity of PLA fibers as studied by XRD and DSC. Thermogravimetric analyses showed that MWCNT loading can decrease the onset degradation temperature of the composites which was attributed to the catalytic effect of metallic residues in MWCNT. Moreover, it was demonstrated that hydrophilicity slightly increased with an increase in MWCNT content. These results show that solution blow spinning can also be used to produce nanocomposite fibers with many potential applications such as in sensors and biosensors.

Analysis of the biofilm proteome of Xylella fastidiosa

Abstract Background Xylella fastidiosa is limited to the xylem of the plant host and the foregut of insect vectors (sharpshooters). The mechanism of pathogenicity of this bacterium differs from other plant pathogens, since it does not present typical genes that confer specific interactions between plant and pathogens (avr and/or hrp). The bacterium is injected directly into the xylem vessels where it adheres and colonizes. The whole process leads to the formation of biofilms, which are considered the main mechanism of pathogenicity. Cells in biofilms are metabolically and phenotypically different from their planktonic condition. The mature biofilm stage (phase of higher cell density) presents high virulence and resistance to toxic substances such as antibiotics and detergents. Here we performed proteomic analysis of proteins expressed exclusively in the mature biofilm of X. fastidiosa strain 9a5c, in comparison to planktonic growth condition. Results We found a total of 456 proteins expressed in the biofilm condition, which correspond to approximately 10% of total protein in the genome. The biofilm showed 37% (or 144 proteins) different protein than we found in the planktonic growth condition. The large difference in protein pattern in the biofilm condition may be responsible for the physiological changes of the cells in the biofilm of X. fastidiosa. Mass spectrometry was used to identify these proteins, while real-time quantitative polymerase chain reaction monitored expression of genes encoding them. Most of proteins expressed in the mature biofilm growth were associated with metabolism, adhesion, pathogenicity and stress conditions. Even though the biofilm cells in this work were not submitted to any stress condition, some stress related proteins were expressed only in the biofilm condition, suggesting that the biofilm cells would constitutively express proteins in different adverse environments. Conclusions We observed overexpression of proteins related to quorum sensing, proving the existence of communication between cells, and thus the development of structuring the biofilm (mature biofilm) leading to obstruction of vessels and development of disease. This paper reports a first proteomic analysis of mature biofilm of X. fastidiosa, opening new perspectives for understanding the biochemistry of mature biofilm growth in a plant pathogen.

A quantitative analysis of current security concerns and solutions for cloud computing

The development of cloud computing services is speeding up the rate in which the organizations outsource their computational services or sell their idle computational resources. Even though migrating to the cloud remains a tempting trend from a financial perspective, there are several other aspects that must be taken into account by companies before they decide to do so. One of the most important aspect refers to security: while some cloud computing security issues are inherited from the solutions adopted to create such services, many new security questions that are particular to these solutions also arise, including those related to how the services are organized and which kind of service/data can be placed in the cloud. Aiming to give a better understanding of this complex scenario, in this article we identify and classify the main security concerns and solutions in cloud computing, and propose a taxonomy of security in cloud computing, giving an overview of the current status of security in this emerging technology.

Influence of growth media and temperature on bacterial adhesion to polystyrene surfaces

Bacterial adhesion to inert surfaces is a complex process influenced by environmental conditions. In this work, the influence of growth medium and temperature on the adhesion of Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus aureus, Micrococcus luteus and Listeria monocytogenes to polystyrene surfaces was studied. Most bacteria demonstrated the highest adhesion when cultured in TSYEA, except S. marcescens, which showed to be positively influenced by the pigment production, favored in poor nutrient media (lactose and peptone agar). P. aeruginosa adhesion to polystyrene increased at low temperatures whatever the medium used. The culture medium influenced the surface properties of the bacteria as assessed by the MATS test.

The Social City : Middle-way approaches to housing and sub-urban golvernmentality in southern Stockholm, 1900-1945

This dissertation deals with the period bridging the era of extreme housing shortages in Stockholm on the eve of industrialisation and the much admired programmes of housing provision that followed after the second world war, when Stockholm district Vällingby became an example for underground railway-serviced ”new towns”. It is argued that important changes were made in the housing and town planning policy in Stockholm in this period that paved the way for the successful ensuing period. Foremost among these changes was the uniquely developed practice of municipal leaseholding with the help of site leasehold rights (Erbbaurecht). The study is informed by recent developments in Foucauldian social research, which go under the heading ’governmentality’. Developments within urban planning are understood as different solutions to the problem of urban order. To a large extent, urban and housing policies changed during the period from direct interventions into the lives of inhabitants connected to a liberal understanding of housing provision, to the building of a disciplinary city, and the conduct of ’governmental’ power, building on increased activity on behalf of the local state to provide housing and the integration and co-operation of large collectives. Municipal leaseholding was a fundamental means for the implementation of this policy. When the new policies were introduced, they were limited to the outer parts of the city and administered by special administrative bodies. This administrative and spatial separation was largely upheld throughout the period, and represented as the parallel building of a ’social’ outer city, while things in the inner ’mercantile’ city proceeded more or less as before. This separation was founded in a radical difference in land holding policy: while sites in the inner city were privatised and sold at market values, land in the outer city was mostly leasehold land, distributed according to administrative – and thus politically decided – priorities. These differences were also understood and acknowledged by the inhabitants. Thorough studies of the local press and the organisational life of the southern parts of the outer city reveals that the local identity was tightly connected with the representations connected to the different land holding systems. Inhabitants in the south-western parts of the city, which in this period was still largely built on private sites, displayed a spatial understanding built on the contradictions between centre and periphery. The inhabitants living on leaseholding sites, however, showed a clear understanding of their position as members of model communities, tightly connected to the policy of the municipal administration. The organisations on leaseholding sites also displayed a deep co-operation with the administration. As the analyses of election results show, the inhabitants also seemed to have felt a greater degree of integration with the society at large, than people living in other parts of the city. The leaseholding system in Stockholm has persisted until today and has been one of the strongest in the world, although the local neo-liberal politicians are currently disposing it off.

Dispersal in free-living, marine, benthic nematodes : passive or active processes?

Meiofauna, and especially marine nematodes are common in sediments around the world. Despite very wide ranging distributions in many nematode species, little is presently known about their dispersal mechanisms shaping these patterns. Rafting, and perhaps ballast water transport has been suggested as viable means for nematode long-range transport. On a much smaller scale other processes have been suggested for their dispersal. They generally include some form of passive suspension into the water column and later on a passive, haphazard settling back towards the bottom. Small-scale phenomena in nematode dispersal were studied by conducting a series of studies at Askö field station, Trosa Archipelago, Baltic proper. Studied aspects were one case of macrofaunal influence on nematode dispersal rate, using an amphipod, Monoporeia affinis as disturbing agent, and three different studies on mechanisms related to settling. The experiments were conducted both in laboratory and field settings. The amphipod Monoporeia affinis did not exert any influence on the dispersal rate in the nematodes. The nematode dispersal was only an effect of time, in the aspect that the more time that past, the more nematodes dispersed from their place of origin. The settling experiments revealed that nematodes do have an active component in their settling behaviour, as they were able to exert influence on the spot where they were to settle. They were able to choose settling spot in response to the food quality of the sediment. It also became evident that contrary to common belief, nematodes are able to extend their presence in the water column far beyond the times that would be predicted considering settling velocities and hydrodynamic conditions alone.

Preparation and characterisation of refractory whiskers and selected alumina composites

A whisker is a common name of single crystalline inorganic fibre of small dimensions, typically 0.5-1 μm in diameter and 20-50 μm in length. Whiskers are mainly used as reinforcement of ceramics. This work describes the synthesis and characterisation of new whisker types. Ti0.33Ta0.33Nb0.33CxN1-x, TiB2, B4C, and LaxCe1-xB6 have been prepared by carbothermal vapour–liquid–solid (CTR-VLS) growth mechanisms in the temperature range 900-1800°C, in argon or nitrogen. Generally, carbon and different suitable oxides were used as whisker precursors. The oxides reacted via a carbothermal reduction process. A halogenide salt was added to form gaseous metal halogenides or oxohalogenides and small amount of a transition metal was added to catalyse the whisker growth. In this mechanism, the whisker constituents are dissolved into the catalyst, in liquid phase, which becomes supersaturated. Then a whisker could nucleate and grow out under continuous feed of constituents. The syntheses of TiC, TiB2, and B4C were followed at ordinary synthesis conditions by means of mass spectrometry (MS), thermogravimetry (TG), differential thermal analysis (DTA) and quenching. The main reaction starting temperatures and reaction time for the different mixtures was revealed, and it was found that the temperature inside the crucible during the reactions was up to 100°C below the furnace set-point, due to endothermic nature of the reactions. Quench experiments showed that whiskers were formed already when reaching the temperature plateau, but the yield increased fast with the holding time and reached a maximum after about 20-30 minutes. Growth models for whisker formation have been proposed. Alumina based composites reinforced by (2-5 vol.%) TiCnano and TiNnano and 25 vol.% of carbide, and boride phases (whiskers and particulates of TiC, TiN, TaC, NbC, (Ti,Ta)C, (Ti,Ta,Nb)C, SiC, TiB2 and B4C) have been prepared by a developed aqueous colloidal processing route followed by hot pressing for 90 min at 1700°C, 28 MPa or SPS sintering for 5 minutes at 1200-1600°C and 75 MPa. Vickers indentation measurements showed that the lowest possible sintering temperature is to prefer from mechanical properties point of view. In the TiNnano composites the fracture mode was typically intergranular, while it was transgranular in the SiCnano composites. The whisker and particulate composites have been compared in terms of e.g. microstructure and mechanical properties. Generally, additions of whiskers yielded higher fracture toughness compared to particulates. Composites of commercially available SiC whiskers showed best mechanical properties with a low spread but all the other whisker phases, especially TiB2, exhibited a great potential as reinforcement materials.

Aislamiento y caracterización de microalgas formadoras de tapetes microbianos asociados a un cultivo hidropónico de plantas halófitas

Programa de Doctorado Ecología y Gestión de los Recursos Vivos Marinos

Genetic characterization and molecular identification of the bloodmeal sources of the potential bluetongue vector Culicoides obsoletus in the Canary Islands, Spain

[EN] Background: Culicoides (Diptera: Ceratopogonidae) biting midges are vectors for a diversity of pathogens including bluetongue virus (BTV) that generate important economic losses. BTV has expanded its range in recent decades, probably due to the expansion of its main vector and the presence of other autochthonous competent vectors. Although the Canary Islands are still free of bluetongue disease (BTD), Spain and Europe have had to face up to a spread of bluetongue with disastrous consequences. Therefore, it is essential to identify the distribution of biting midges and understand their feeding patterns in areas susceptible to BTD. To that end, we captured biting midges on two farms in the Canary Islands (i) to identify the midge species in question and characterize their COI barcoding region and (ii) to ascertain the source of their bloodmeals using molecular tools.Methods: Biting midges were captured using CDC traps baited with a 4-W blacklight (UV) bulb on Gran Canaria and on Tenerife. Biting midges were quantified and identified according to their wing patterns. A 688 bp segment of the mitochondrial COI gene of 20 biting midges (11 from Gran Canaria and 9 from Tenerife) were PCR amplified using the primers LCO1490 and HCO2198. Moreover, after selected all available females showing any rest of blood in their abdomen, a nested-PCR approach was used to amplify a fragment of the COI gene from vertebrate DNA contained in bloodmeals. The origin of bloodmeals was identified by comparison with the nucleotide-nucleotide basic alignment search tool (BLAST). Results: The morphological identification of 491 female biting midges revealed the presence of a single morphospecies belonging to the Obsoletus group. When sequencing the barcoding region of the 20 females used to check genetic variability, we identified two haplotypes differing in a single base. Comparison analysis using the nucleotide-nucleotide basic alignment search tool (BLAST) showed that both haplotypes belong to Culicoides obsoletus, a potential BTV vector. As well, using molecular tools we identified the feeding sources of 136 biting midges and were able to confirm that C. obsoletus females feed on goats and sheep on both islands.Conclusions: These results confirm that the feeding pattern of C. obsoletus is a potentially important factor in BTV transmission to susceptible hosts in case of introduction into the archipelago. Consequently, in the Canary Islands it is essential to maintain vigilance of Culicoides-transmitted viruses such as BTV and the novel Schmallenberg virus.

Computational methods for the analysis of protein structure and function

The vast majority of known proteins have not yet been experimentally characterized and little is known about their function. The design and implementation of computational tools can provide insight into the function of proteins based on their sequence, their structure, their evolutionary history and their association with other proteins. Knowledge of the three-dimensional (3D) structure of a protein can lead to a deep understanding of its mode of action and interaction, but currently the structures of <1% of sequences have been experimentally solved. For this reason, it became urgent to develop new methods that are able to computationally extract relevant information from protein sequence and structure. The starting point of my work has been the study of the properties of contacts between protein residues, since they constrain protein folding and characterize different protein structures. Prediction of residue contacts in proteins is an interesting problem whose solution may be useful in protein folding recognition and de novo design. The prediction of these contacts requires the study of the protein inter-residue distances related to the specific type of amino acid pair that are encoded in the so-called contact map. An interesting new way of analyzing those structures came out when network studies were introduced, with pivotal papers demonstrating that protein contact networks also exhibit small-world behavior. In order to highlight constraints for the prediction of protein contact maps and for applications in the field of protein structure prediction and/or reconstruction from experimentally determined contact maps, I studied to which extent the characteristic path length and clustering coefficient of the protein contacts network are values that reveal characteristic features of protein contact maps. Provided that residue contacts are known for a protein sequence, the major features of its 3D structure could be deduced by combining this knowledge with correctly predicted motifs of secondary structure. In the second part of my work I focused on a particular protein structural motif, the coiled-coil, known to mediate a variety of fundamental biological interactions. Coiled-coils are found in a variety of structural forms and in a wide range of proteins including, for example, small units such as leucine zippers that drive the dimerization of many transcription factors or more complex structures such as the family of viral proteins responsible for virus-host membrane fusion. The coiled-coil structural motif is estimated to account for 5-10% of the protein sequences in the various genomes. Given their biological importance, in my work I introduced a Hidden Markov Model (HMM) that exploits the evolutionary information derived from multiple sequence alignments, to predict coiled-coil regions and to discriminate coiled-coil sequences. The results indicate that the new HMM outperforms all the existing programs and can be adopted for the coiled-coil prediction and for large-scale genome annotation. Genome annotation is a key issue in modern computational biology, being the starting point towards the understanding of the complex processes involved in biological networks. The rapid growth in the number of protein sequences and structures available poses new fundamental problems that still deserve an interpretation. Nevertheless, these data are at the basis of the design of new strategies for tackling problems such as the prediction of protein structure and function. Experimental determination of the functions of all these proteins would be a hugely time-consuming and costly task and, in most instances, has not been carried out. As an example, currently, approximately only 20% of annotated proteins in the Homo sapiens genome have been experimentally characterized. A commonly adopted procedure for annotating protein sequences relies on the "inheritance through homology" based on the notion that similar sequences share similar functions and structures. This procedure consists in the assignment of sequences to a specific group of functionally related sequences which had been grouped through clustering techniques. The clustering procedure is based on suitable similarity rules, since predicting protein structure and function from sequence largely depends on the value of sequence identity. However, additional levels of complexity are due to multi-domain proteins, to proteins that share common domains but that do not necessarily share the same function, to the finding that different combinations of shared domains can lead to different biological roles. In the last part of this study I developed and validate a system that contributes to sequence annotation by taking advantage of a validated transfer through inheritance procedure of the molecular functions and of the structural templates. After a cross-genome comparison with the BLAST program, clusters were built on the basis of two stringent constraints on sequence identity and coverage of the alignment. The adopted measure explicity answers to the problem of multi-domain proteins annotation and allows a fine grain division of the whole set of proteomes used, that ensures cluster homogeneity in terms of sequence length. A high level of coverage of structure templates on the length of protein sequences within clusters ensures that multi-domain proteins when present can be templates for sequences of similar length. This annotation procedure includes the possibility of reliably transferring statistically validated functions and structures to sequences considering information available in the present data bases of molecular functions and structures.

Transformation, Progression und Zellinienspezifität der chronischen myeloischen Leukämie

Die Analyse der CML-Zellinie K562 mittels Fluoreszenz in situ Hybridisierung (FISH), Multiplex-FISH (M-FISH) und comparativer genomischer Hybridisierung (CGH) ergab einen hypotriploiden Karyotyp mit 67 Chromosomen und 21 verschiedenen Marker-Chromosomen. Das bei über 90% der CML-Patienten nachgewiesene Ph-Chromosom entsteht durch die reziproke Translokation t(9;22)(q34;q11). Bei 5 - 10% der Patienten resultiert das Ph-Chromosom aus varianten Translokation. Anhand der Untersuchung dreier varianter Translokation mittels Bruchpunkt-übergreifender FISH-Proben für die BCR- und ABL-Gene werden drei verschiedene Mechanismen der Entstehung komplexer Translokationen dargestellt. Das Auftreten sekundärer Aberrationen wurde in 15 CML-Blastenkrisen untersucht. Zudem wurde anhand der CGH-Analyse von CD34-positiven Zellen, Monozyten, Granulozyten und T-Zellen die Zellinienspezifität sekundärer Aberrationen untersucht. In einem Fall wurde eine sekundäre Aberration in allen vier Fraktionen gefunden. In zwei Fällen traten sekundäre Aberrationen in allen untersuchten Fraktionen mit Ausnahme der T-Zellen auf. Aufgrund dieser Ergebnisse lassen sich zwei alternative Modelle der Tumor-Progression der CML ableiten: 1. Sekundäre Mutatonen treten vor der Differenzierung der hämatopoetischen Stammzelle auf. 2. Sekundäre Mutationen treten in einer hämatopoetischen Vorläuferzelle nach der T-Zell-Differenzierung auf.

Procedure e strumenti innovativi per lo sfruttamento sostenibile delle risorse minerarie

L'approvvigionamento di risorse minerali e la tutela dell'ambiente sono spesso considerate attività contrapposte ed inconciliabili, ma in realtà rappresentano due necessità imprescindibili per le società moderne. Le georisorse, in quanto non rinnovabili, devono essere valorizzate in maniera efficiente, adoperando strumenti che garantiscano la sostenibilità ambientale, sociale ed economica degli interventi estrattivi. La necessità di tutelare il territorio e migliorare la qualità della vita delle comunità locali impone alla Pubblica Amministrazione di implementare misure per la riqualificazione di aree degradate, ma fino ai primi anni '90 la normativa di settore non prevedeva strumenti a tal proposito, e ciò ha portato alla proliferazione di siti estrattivi dismessi e abbandonati senza interventi di recupero ambientale. Il presente lavoro di ricerca fornisce contributi innovativi alla pianificazione e progettazione sostenibile delle attività estrattive, attraverso l'adozione di un approccio multidisciplinare alla trattazione del tema e l'utilizzo esperto dei Sistemi Informativi Geografici, in particolare GRASS GIS. A seguito di una approfondita analisi in merito agli strumenti e le procedure adottate nella pianificazione delle Attività Estrattive in Italia, sono stati sviluppati un metodo di indagine ed un sistema esperto per la previsione ed il controllo delle vibrazioni indotte nel terreno da volate in cava a cielo aperto, che consentono di ottimizzare la progettazione della volata e del sistema di monitoraggio delle vibrazioni grazie a specifici strumenti operativi implementati in GRASS GIS. A supporto di una più efficace programmazione di interventi di riqualificazione territoriale, è stata messa a punto una procedura per la selezione di siti dismessi e di potenziali interventi di riqualificazione, che ottimizza le attività di pianificazione individuando interventi caratterizzati da elevata sostenibilità ambientale, economica e sociale. I risultati ottenuti dimostrano la necessità di un approccio esperto alla pianificazione ed alla progettazione delle attività estrattive, incrementandone la sostenibilità attraverso l'adozione di strumenti operativi più efficienti.

adaptive capabilities of the pi3k/akt/mtor pathway in acute myeloid leukemia revealed by the use of selective inhibitors

Because of its aberrant activation, the PI3K/AKT/mTOR signaling pathway represents a pharmacological target in blast cells from patients with acute myelogenous leukemia (AML). Using Reverse Phase Protein Microarrays (RPMA), we have analyzed 20 phosphorylated epitopes of the PI3K/Akt/mTor signal pathway of peripheral blood and bone marrow specimens of 84 patients with newly diagnosed AML. Fresh blast cells were grown for 2 h, 4 h or 20 h untreated or treated with a panel of phase I or phase II Akt allosteric inhibitors, either alone or in combination with the mTOR kinase inhibitor Torin1 or the broad RTK inhibitor Sunitinib. By unsupervised hierarchical clustering a strong phosphorylation/activity of most of the sampled members of the PI3K/Akt/mTOR pathway was observed in 70% of samples from AML patients. Remarkably, however, we observed that inhibition of Akt phosphorylation, as well as of its substrates, was transient, and recovered or even increased far above basal level after 20 h in 60% samples. We demonstrated that inhibition of Akt induces FOXO-dependent insulin receptor expression and IRS-1 activation, attenuating the effect of drug treatment by reactivation of PI3K/Akt. Consistent with this model we found that combined inhibition of Akt and RTKs is much more effective than either alone, revealing the adaptive capabilities of signaling networks in blast cells and highliting the limations of these drugs if used as monotherapy.

Biodegradable systems for the development of functional materials

This PhD work was aimed to design, develop, and characterize gelatin-based scaffolds, for the repair of defects in the muscle-skeletal system. Gelatin is a biopolymer widely used for pharmaceutical and medical applications, thanks to its biodegradability and biocompatibility. It is obtained from collagen via thermal denaturation or chemical-physical degradation. Despite its high potential as biomaterial, gelatin exhibits poor mechanical properties and a low resistance in aqueous environment. Crosslinking treatment and enrichment with reinforcement materials are thus required for biomedical applications. In this work, gelatin based scaffolds were prepared following three different strategies: films were prepared through the solvent casting method, electrospinning technique was applied for the preparation of porous mats, and 3D porous scaffolds were prepared through freeze-drying. The results obtained on films put into evidence the influence of pH, crosslinking and reinforcement with montmorillonite (MMT), on the structure, stability and mechanical properties of gelatin and MMT/gelatin composites. The information acquired on the effect of crosslinking in different conditions was utilized to optimize the preparation procedure of electrospun and freeze-dried scaffolds. A successful method was developed to prepare gelatin nanofibrous scaffolds electrospun from acetic acid/water solution and stabilized with a non-toxic crosslinking agent, genipin, able to preserve their original morphology after exposure to water. Moreover, the co-electrospinning technique was used to prepare nanofibrous scaffolds at variable content of gelatin and polylactic acid. Preliminary in vitro tests indicated that the scaffolds are suitable for cartilage tissue engineering, and that their potential applications can be extended to cartilage-bone interface tissue engineering. Finally, 3D porous gelatin scaffolds, enriched with calcium phosphate, were prepared with the freeze-drying method. The results indicated that the crystallinity of the inorganic phase influences porosity, interconnectivity and mechanical properties. Preliminary in vitro tests show good osteoblast response in terms of proliferation and adhesion on all the scaffolds.