Trattamento delle lesioni osteocondrali di grado I e II mediante infiltrazione intra-articolare di fattori di crescita autologhi (plasma rich in platelets)

The use of Platelet-rich plasma (PRP), a platelet concentrate made of autogenous blood, is becoming use in the treatment of some orthopaedic diseases. The aim of this study is to assess the effect of PRP on articular cartilage defects in a rabbit model (10 subjects). Twenty osteochondral defects created in the femoropatellar groove, were in ten cases left untreated and in ten cases treated with autogenous PRP. PRP was obtained using a double centrifugation of the rabbit’s blood harvested before the operation. 30 days after the lesion was made in both knee, the left one in each rabbit was treated by a PRP injection, followed by other two injection at 45 and 60 days. Tissue specimens were assessed by macroscopic examination and histological evaluation, that showed a better healing of the lesions in the knee treated with PRP injections.

Purging e alte dosi di chemioterapia con reinfusione di cellule staminali autologhe in linfomi non Hodgkin follicolari resistenti/refrattari

In the era of monoclonal antibodies the role of autologous stem cell transplantation (ASCT) in the management of follicular lymphoma (FL) is still debated. To evaluate the safety and efficacy of myeloablative therapy with rescue of purged or unpurged harvests in FL pts. At our institution form 1997 to 2007 28 pts with refractory/resistant FL were eligible for ASCT. Before high dose therapy they received 2-3 cycles of CHOP-like regimen (ACOD), followed by Cyclophosphamide 4g/mq to mobilize the stem cells (SC). After SC collection the pts underwent 3 cycles of subcutaneous Cladribine at a daily dose of 0,14-0,10 mg/Kg for Day 1-5 every 3-4 weeks. The conditioning regimen was based on Mitoxantrone 60mg/mq + Melphalan 180 mg/mq, followed by SC re-infusion 24-hours later and G-CSF starting 24 hours after re-infusion. In 19 pts the SC underwent purging: in 10 harvests the CD34+ were selected by immunomagnetic beads, while in the other 9 pts, only Rituximab was used as “purging in vivo” agent. The remaining 9 pts received unpurged SC. Before ASCT 11 pts were in complete response (CR), 9 in partial response (PR) and 2 in stable disease. Two pts were not eligible for ASCT because of progressive disease (PD). The remaining 25 pts were eligible for ASCT. The engraftment was at a median of 11 days for leucocytes and 14 days for platelets (>20.000/mmc), with a delay of one day in the pts, who received purged SC. Grade 3-4 mucositis was described in 8 pts. During aplasia a 48% infection rate was reported, without differences between pts with purged or unpurged SC. One patient in CR presented myelodysplastic syndrome at 18 months from ASCT. After ASCT 22 pts were in CR, 2 in PR and one patient were not valuable, because died before response assessment. Nine pts in CR showed PD at a median time of 14 months from ASCT. With a median follow up of 5 years (range 2 months -10 years), 22 pts are alive and 11 (44%) in CR. Ten pts died, 5 for progressive disease and 5 for treatment-related causes; in particular 7 of them received in-vitro purged SC. Conclusions: Our chemotherapy regimen, which included the purine analogue Cladribine in the induction phase, seems safe and feasible. The high rate of CR reported and the sustained freedom from progression up to now, makes such modality of treatment a valid option principally in relapsing FL patients. In our experience, the addition of a monoclonal antibody as part of treatment confirms its role “in vivo purging” without observing an increased incidence of infection.

Characterization and modeling of the barrier properties in nanostructured systems

The object of the present study is the process of gas transport in nano-sized materials, i.e. systems having structural elements of the order of nanometers. The aim of this work is to advance the understanding of the gas transport mechanism in such materials, for which traditional models are not often suitable, by providing a correct interpretation of the relationship between diffusive phenomena and structural features. This result would allow the development new materials with permeation properties tailored on the specific application, especially in packaging systems. The methods used to achieve this goal were a detailed experimental characterization and different simulation methods. The experimental campaign regarded the determination of oxygen permeability and diffusivity in different sets of organic-inorganic hybrid coatings prepared via sol-gel technique. The polymeric samples coated with these hybrid layers experienced a remarkable enhancement of the barrier properties, which was explained by the strong interconnection at the nano-scale between the organic moiety and silica domains. An analogous characterization was performed on microfibrillated cellulose films, which presented remarkable barrier effect toward oxygen when it is dry, while in the presence of water the performance significantly drops. The very low value of water diffusivity at low activities is also an interesting characteristic which deals with its structural properties. Two different approaches of simulation were then considered: the diffusion of oxygen through polymer-layered silicates was modeled on a continuum scale with a CFD software, while the properties of n-alkanthiolate self assembled monolayers on gold were analyzed from a molecular point of view by means of a molecular dynamics algorithm. Modeling transport properties in layered nanocomposites, resulting from the ordered dispersion of impermeable flakes in a 2-D matrix, allowed the calculation of the enhancement of barrier effect in relation with platelets structural parameters leading to derive a new expression. On this basis, randomly distributed systems were simulated and the results were analyzed to evaluate the different contributions to the overall effect. The study of more realistic three-dimensional geometries revealed a prefect correspondence with the 2-D approximation. A completely different approach was applied to simulate the effect of temperature on the oxygen transport through self assembled monolayers; the structural information obtained from equilibrium MD simulations showed that raising the temperature, makes the monolayer less ordered and consequently less crystalline. This disorder produces a decrease in the barrier free energy and it lowers the overall resistance to oxygen diffusion, making the monolayer more permeable to small molecules.

Treatment of knee articular cartilage defects: surgical strategies, results and analysis of factors determining the clinical outcome

Articular cartilage lesions, with their inherent limited healing potential, are hard to treat and remain a challenging problem for orthopedic surgeons. Despite the development of several treatment strategies, the real potential of each procedure in terms of clinical benefit and effects on the joint degeneration processes is not clear. Aim of this PhD project was to evaluate the results, both in terms of clinical and imaging improvement, of new promising procedures developed to address the challenging cartilage pathology. Several studies have been followed in parallel and completed over the 3-year PhD, and are reported in detail in the following pages. In particular, the studies have been focused on the evaluation of the treatment indications of a scaffold based autologous chondrocyte implantation procedure, documenting its results for the classic indication of focal traumatic lesions, as well as its use for the treatment of more challenging patients, older, with degenerative lesions, or even as salvage procedure for more advanced stages of articular degeneration. The second field of study involved the analysis of the results obtained treating lesions of the articular surface with a new biomimetic osteochondral scaffold, which showed promise for the treatment of defects where the entire osteochondral unit is involved. Finally, a new minimally invasive procedure based on the use of growth factors derived from autologous platelets has been explored, showing results and underlining indicatios for the treatment of cartilage lesions and different stages of joint degeneration. These studies shed some light on the potential of the evaluated procedures, underlining good results as well as limits, they give some indications on the most appropriate candidates for their application, and document the current knowledge on cartilage treatment procedures suggesting the limitations that need to be addressed by future studies to improve the management of cartilage lesions.

Caratterizzazione e ruolo di PKCε e PKCδ in modelli di differenziamento megacariocitario normale e patologico

La PKCε e la PKCδ, chinasi ubiquitariamente distribuite e ad azione pleiotropica, sono implicate del differenziamento, sopravvivenza e proliferazione cellulare. Esse sono coinvolte nel processo differenziativo delle cellule staminali ematopoietiche e in fenomeni patologici associati al compartimento sanguigno. In questa tesi sono presentati i risultati riguardanti lo studio in vitro del ruolo di PKCε e PKCδ nel contesto del differenziamento megacariocitario, in particolare si caratterizza l’espressione e la funzione di queste chinasi nel modello umano e nel modello murino di Megacariocitopoiesi, normale e patologica. Confrontando le cinetiche dei due modelli presi in analisi nello studio è stato possibile osservare come in entrambi PKCε e PKCδ dimostrino avere una chiara e specifica modulazione nel progredire del processo differenziativo. Questi dati, se confrontati, permettono di affermare che PKCε e PKCδ presentano un pattern di espressione opposto e, nel modello umano rispetto a quello murino, reciproco: nell’uomo i livelli di PKCε devono essere down-modulati, mentre nel topo, al contrario, i livelli della chinasi risultano up-modulati durante lo stesso processo. Analogamente, le CD34+ in differenziazione presentano una costante e maggiore espressione di PKCδ durante la maturazione MK, mentre nel modello murino tale proteina risulta down-modulata nella fase più tardiva di formazione della piastrina. Le chinasi mostrano in oltre di agire, nei due modelli, attraverso pathways distinti e cioè RhoA nel topo e Bcl-xL nell’uomo. È stato inoltre verificato che l’aberrante differenziamento MK osservato nella mielofibrosi primaria (PMF), è associato a difetti di espressione di PKCε e di Bcl-xL e che una forzata down-modulazione di PKCε porta ad un ripristino di un normale livello di espressione di Bcl-xL così come della popolazione di megacariociti formanti propiastrine. I dati ottenuti indicano quindi che PKCε e PKCδ svolgono un ruolo importante nel corretto differenziamento MK e che PKCε potrebbe essere un potenziale nuovo target terapeutico nelle PMF.

Basi molecolari ed implicazioni fisio-patologiche dell'alterata glicosilazione di IgG nell'invecchiamento

Introduzione: Le catene N-linked associate al principale sito di N-glicosilazione (Asn297) delle IgG sono di tipo bi-antennario e presentano una grande microeterogeneità in quanto una o entrambe le antenne possono terminare con uno o due residui di acido sialico, galattosio o N-acetilglucosammina ed essere core-fucosilate. Nell’invecchiamento e in malattie infiammatorie aumenta la percentuale di glicani associati alle catene pesanti delle IgG privi del galattosio terminale (IgG-G0). La glicosilazione enzimatica delle proteine è classicamente un processo intracellulare, sebbene recenti studi abbiano messo in evidenza la possibilità di una glicosilazione ecto-cellulare in quanto le piastrine sono ottimi donatori di nucleotidi-zuccheri. Scopo: Misurare le attività delle glicosiltrasferasi ST6Gal1 e B4GalT plasmatiche (potenzialmente responsabili della glicosilazione di proteine plasmatiche) in soggetti di entrambi i sessi e di età compresa tra 5 e 105 anni e correlarle con lo stato di glicosilazione di IgG circolanti (analizzato mediante lectin-blot) e il GlycoAge test, un noto marcatore di invecchiamento, espresso come il logaritmo del rapporto tra gli N-glicani agalattosilati e di-galattosilati associati a glicoproteine plasmatiche. Risultati e conclusioni: I dati ottenuti indicano che: 1) l’attività B4GalT si propone come nuovo marcatore di invecchiamento perché aumenta linearmente con l’età; 2) la ST6Gal1 è maggiormente espressa solo nei bambini e negli over 80; 3) le attività delle due glicosilatransferasi non risultano correlate in modo significativo né tra loro né con il GlycoAge test, indicando che questi tre marcatori siano espressioni di diversi quadri fisio-patologici legati all’invecchiamento; 4) con l’età si ha una predominanza di glicoforme di IgG pro-infiammatorie, ovvero prive dell’acido sialico, del galattosio terminali e del core fucose; 5) l’attività della ST6Gal1 e B4GalT risultano in controtendenza con il grado di sialilazione e galattosilazione delle IgG, indicando quindi che la loro glicosilazione non avviene a livello extracellulare.

Allestimento di modello sperimentale su animali di tessuto osseo ingegnerizzato

Questo studio ha valutato l'efficacia di un approccio rigenerativo utilizzando cellule staminali mesenchimali (MSC) e uno scaffold di idrossiapatite pura e porosa (HA) progettata con tecnologia CAD-CAM per sostituire il condilo dell'articolazione temporomandibolare (ATM). Metodi.Uno scaffolds di HA con porosità totale del 70% è stato prototipato per sostituire i due condili temporomandibolari (sinistro e destro) dello stesso animale. MSC sono state ottenute dalla cresta iliaca ed espanse in coltura. Guide chirurgiche su misura sono state create e utilizzate per esportare la pianificazione virtuale delle linee di taglio dell'osso nell'ambiente chirurgico. Sei pecore sono state sacrificate a 4 mesi dopo l'intervento.Gli scaffold sono stati espiantati, campioni istologici sono stati preparati, ed è stata eseguota l'analisi istomorfometrica. Risultati.L'analisi della riduzione di porosità per apposizione di osso neoformato mostrata una differenza statisticamente significativa tra la formazione ossea nei condili carichi di MSC rispetto ai condili senza (

Peptide-based low molecular weight gelators for the preparation of self-assembled materials

Low molecular weight gelators (LMWGs) based on pseudo-peptides are here studied for the preparation of supramolecular materials. These compounds can self-assemble through non-covalent interactions such as hydrogen bonds and π-π stacking, forming fibres and gels. A wide variety of materials can be prepared starting from these building blocks, which can be tuned and functionalised depending on the application. In this work, derivatives of the three aromatic amino acids L-Phenylalanine, L-Tyrosine and L-DOPA (3,4-dihydroxiphenylalanine) were synthesised and tested as gelators for water or organic solvents. First, the optimal gelating conditions were studied for each compound, varying concentration, solvent and trigger. Then the materials were characterised in terms of mechanical properties and morphology. Water remediation from dye pollution was the first focus of this work. Organogels were studied as absorbent of dyes from contaminated water. Hydrogels functionalised with TiO2 nanoparticles and graphene platelets were proposed as efficient materials for the photo-degradation of dyes. An efficient method for the incorporation of graphene inside hydrogels using the gelator itself as dispersant was proposed. In these materials a high storage modulus coexists with good self-healing and biocompatibility. The incorporation of a mineral phase inside the gel matrix was then investigated, leading to the preparation of composite organic/inorganic materials. In a first study, the growth of calcium carbonate crystals was achieved inside the hydrogel, which preserved its structure after crystal formation. Then the self-assembled fibres made of LMWGs were used for the first time instead of the polymeric ones as reinforcement inside calcium phosphate cements (CPCs) for bone regeneration. Gel-to-crystal transitions occurring with time in a metastable gel were also examined. The formation of organic crystals in gels can be achieved in multicomponent systems, in which a second gelator constitutes the independent gel network. Finally, some compounds unable to gelate were tested as underwater adhesives.

Outcomes of global coagulation assays in patients with Philadelphia-negative myeloproliferative neoplasms with respect to genetic determinants of clonal progression

Classical myeloproliferative neoplasms (MPNs) are hematopoietic stem cell disorders that manifest with inflammation, promotion of atherosclerosis, hypercoagulability, fibrosis, and clonal evolution. The complex biological background lends itself to multi-omics studies. We have previously shown that reduced platelet fibrinogen receptor (PFR) expression may follow hyperactivation of plasma-dependent mechanisms, such as tissue factor (TF) release, unbalanced thrombin generation, involvement of protease-activated receptors (PARs). Acetylsalicylic acid (ASA) helped to restore the expression of PFRs. In this study, we enrolled 53 MPN patients, subjecting them to advanced genetic testing (panel of 30 genes in NGS), global coagulation testing (Rotational Thromboelastometry - ROTEM) and cytofluorometric determination of PFRs. ROTEM parameters appear to differ considerably depending on the type of pathology under investigation, cell count, and selected mutations. Essential thrombocythemia (ET) and CALR mutation appear to correlate with increased efficiency of both classical coagulation pathways, with significantly more contracted clot formation times (CFTs). In contrast, primary myelofibrosis (PMF) and polycythemia vera (PV) show greater imbalances in the hemostatic system. PV, probably due to its peculiar hematological features, shows a lengthening of the CFT and, at the same time, a selective contraction of parameters in INTEM with the increase of platelets and white blood cells. PMF - in contrast - seems to exploit the extrinsic pathway more to increase cell numbers. The presence of DNMT3A mutations is associated with reduced clotting time (CT) in EXTEM, while ASXL1 causes reduced maximal lysis (ML). EZH2 could be responsible for the elongation of CFT in INTEM assay. In addition, increased PFR expression is associated with history of hemorrhage and sustained CT time in FIBTEM under ASA prophylaxis. Our findings corroborate the existing models on the connection between fibrosis, genetic complexity, clonal progression, and hypercoagulability. Global coagulation assays and PFR expression are potentially useful tools for dynamic evaluation of treatments’ outcomes.

Kissing stenting of aortic bifurcation for aorto-iliac obstructive disease: a comparison between bare metal stents and covered stents

INTRODUCTION Aim of this multicentric study:to compare the short-and mid-term results of bare metal stents(BMS)and covered stents(CS)in the Kissing Stent(KS)technique. METHODS Patients undertaking a KS with BMS or CS between January 2017-August 2021 included. Morphological features of plaques were classified as per the extension of calcifications and thrombosis. Every endpoint and outcome was compared in relation to BMS or CS. All patients included received dual anti-platelets DAPT)for at least one month. RESULTS Thirty-four patients enrolled,17 treated with BMS and 17 with CS. Average age 66 years. The 80% of patients were part of TASC C-D categories. DAPT was administered to 82.4%(28/34)of patients with a mean duration of 4.4±1.6 months. Mean follow-up 32.1±17.8 months. Technical Success was 100%. Immediate Clinical Success was reached in 29 cases(85.3%). Immediate and 30-day Clinical Success was higher in CS(64.7% vs 100%, p=.01). Overall Clinical Success at 1-year follow-up was 91.2%,and resulted significantly higher in CS(82.4% vs 100%,p .04). Overall Primary Patency,Assisted Patency,and Secondary Patency at 30 days were 97.1%,97.1%,and 100%,without differences between BMS and CS(94.1% vs 100%,94.1% vs 100%,and 100% vs 100%;p =.7). Two cases(5.9%)of thrombosis were registered,and both occurred within 3 months after the procedure and both in the BMS,without statistical differences with the CS group(11.8% vs 0%,p .48). Both cases of thrombosis occurred in patients who were not treated with dual antiplatelet therapy(33.3% vs 0%,p .027). Survival statistically differed only at the mean follow-up in favour of CS(70.6% and 100%,p .04). CONCLUSIONS The endovascular approach is currently safe and effective in the treatment of AIOD,and KS offers excellent results in particular if performed with CS; however,no statistically significant differences emerged between the two types of stents in terms of patency,reintervention,and complications. DAPT seems to warrant the best results in terms of patency,although there is still no consensus about the ideal duration of administration.

Policitemia Vera: scoperta di saggi di biopsia liquida finalizzata a identificare i biomarcatori correlati al rischio trombotico

La Policitemia Vera (PV) è una neoplasia mieloproliferativa con un aumentato rischio di trombosi e di progressione verso la Mielofibrosi. L'infiammazione cronica è comunemente osservata nelle neoplasie mieloproliferative, compresa la PV. La rete infiammatoria, tra le varie componenti, comprende le vescicole extracellulari (EVs), che svolgono un ruolo nella comunicazione cellula-cellula. Inoltre, le componenti microbiche circolanti sono state recentemente indicate come potenziali modificatori dell'infiammazione, della coagulazione e dell’emopoiesi in generale. Qui abbiamo studiato il DNA microbico delle EVs circolanti attraverso. Sangue periferico e feci sono stati raccolti da pazienti con PV (n=38) e da donatori sani (n=30). Le EVs circolanti derivate da megacariociti (MK) e piastrine (PLT) sono state analizzate mediante citometria a flusso. Dopo l'estrazione del DNA microbico dalle feci e dalle EV isolate, è stata sequenziata la regione V3-V4 del 16S rDNA. La percentuale di EVs di MK era ridotta nei pazienti con PV rispetto ai donatori sani. Al contrario, la proporzione di EVs di PLT era aumentata. La PV è stata associata anche a una firma del DNA microbico delle EVs isolate con una maggiore diversità e una composizione microbica distinta rispetto alla controparte sana. Nei pazienti con PV c’è una maggiore proporzione di EVs associate al lipopolisaccaride. Il profilo del microbioma intestinale non differiva tra PV e doantori. Inoltre, l'aumento della proporzione di EVs di MK e la riduzione di EVs di piastre identificavano i pazienti con pregressa trombosi. Le EVs dei pazienti con trombosi erano impoverite di DNA di Staphylococcus ma arricchite di DNA di Actinobacteria e Anaerococcus. Inoltre, questi pazienti avevano livelli più bassi di EVs associate al lipopolisaccaride. I pazienti con fibrosi midollare avevano una maggiore proporzione di PE-EV ed erano arricchite in DNA di Collinsella e Flavobacterium. Questi dati possono contribuire a perfezionare la prognosi della PV e a identificare nuovi bersagli farmacologici.

Clinical impact of next-generation sequencing multi-gene panel highlighting the landscape of germline alterations in ovarian cancer patients

BRCA1 and BRCA2 are the most frequently mutated genes in ovarian cancer (OC), crucial both for the identification of cancer predisposition and therapeutic choices. However, germline variants in other genes could be involved in OC susceptibility. We characterized OC patients to detect mutations in genes other than BRCA1/2 that could be associated with a high risk to develop OC, and that could permit patients to enter the most appropriate treatment and surveillance program. Next-Generation Sequencing analysis with a 94-gene panel was performed on germline DNA of 219 OC patients. We identified 34 pathogenic/likely-pathogenic variants in BRCA1/2 and 38 in other 21 genes. Patients with pathogenic/likely-pathogenic variants in non-BRCA1/2 genes developed mainly OC alone compared to the other groups that developed also breast cancer or other tumors (p=0.001). Clinical correlation analysis showed that low-risk patients were significantly associated with platinum sensitivity (p<0.001). Regarding PARP inhibitors (PARPi) response, patients with pathogenic mutations in non-BRCA1/2 genes had significantly worse PFS and OS. Moreover, a statistically significant worse PFS was found for every increase of one thousand platelets before PARPi treatment. To conclude, knowledge about molecular alterations in genes beyond BRCA1/2 in OC could allow for more personalized diagnostic, predictive, prognostic, and therapeutic strategies for OC patients.