Παρουσίαση Διδακτορικής Διατριβής κ. Βαρβάρας Πλατανιά

01 Νοεμβρίου 2024

Πρόσκληση σε Δημόσια Παρουσίαση της Διδακτορικής Διατριβής της

κ. Βαρβάρας Πλατανιά

Επιβλέπουσα Καθηγήτρια: Μαρία Χατζηνικολαΐδου

(Σύμφωνα με το άρθρο 95, παρ. 3 του Ν. 4957/2022, ΦΕΚ 141 τ. Α΄/21.7.2022)

Την Τρίτη 5 Νοεμβρίου 2024 και ώρα 11:00 στην αίθουσα Τηλεκπαίδευσης Ε130 του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών του Πανεπιστημίου Κρήτης, θα γίνει η δημόσια παρουσίαση και υποστήριξη της Διδακτορικής Διατριβής της υποψήφιας διδάκτορος του Τμήματος Επιστήμης και Μηχανικής Υλικών κ. Βαρβάρας Πλατανιά, με θέμα:

«3D Bioprinting of Vascularized Bone Grafts Using Human Adult Stem Cells and Cell-Instructive Biomaterials under Mechanical Stimulation»

Περίληψη

Current medical practice still faces significant challenges in treating large bone defects caused by trauma or disease. The main causes of large graft failure are inner graft necrosis and lack of integration with the host tissue due to poor vascularization. Developing bone grafts that can restore vascular function to the regenerating bone tissue has been the most difficult aspect to address. This thesis explores the critical role of vascularization in enhancing bone tissue engineering outcomes.

Acknowledging the potential of 3D bioprinting in bioengineering complex tissues, this study introduces a dual-layered 3D bioprinted vascularized bone model aiming to promote bone regeneration under physiological mechanical loading. The inner layer comprises a vascular-like matrix created from a nanocomposite ink of gellan gum, laponite, and platelet-rich plasma (PRP), with laponite serving as a carrier for the PRP-containing bioactive growth factors, along with Wharton-jelly mesenchymal stem cells. The outer layer features a bone-like matrix containing bone marrow mesenchymal stem cells encapsulated in a photocrosslinkable blend of poly(ethylene glycol) diacrylate (PEGDA), gelatin, and poly(vinyl alcohol). The electrically conductive poly(3,4-ethylenedioxythiophene) (PEDOT) is introduced in the outer layer to enhance the activity of voltage-gated channels, facilitating calcium ion flow across the cell membrane, amplifying the signal triggered by mechanical stimulation.

Dynamic cell cultures performed in the presence of mechanical stimulation within a bioreactor were employed to mimic the physiological environment of native bone tissue. The synergistic cellular and molecular interactions of the dual-layered constructs significantly enhance the osteogenic and angiogenic differentiation due to paracrine signaling. Key markers of osteogenesis and angiogenesis showed significant upregulation in response to mechanical stimulation, particularly in the dynamic cultures. The complex bioprinted constructs demonstrated excellent in vitro biocompatibility, without observing any adverse foreign body reaction following in vivo subcutaneous implantation in mice. The mechanoresponsive biofabricated platform has great potential to promote vascularized bone regeneration.

Αιτήσεις για κατατακτήριες εξετάσεις

31 Οκτωβρίου 2024

Οι αιτήσεις για κατατακτήριες εξετάσεις θα γίνουν από 1-15/11/2024 μέσω της πλατφόρμας:   https://eservices.uoc.gr/cases/foititikes-aitiseis/ .

Παρουσίαση Διδακτορικής Διατριβής του κ. Νικολάου-Αθανασίου Μπούρκερ

30 Οκτωβρίου 2024

Πρόσκληση σε Δημόσια Παρουσίαση της Διδακτορικής Διατριβής

του κ. Νικολάου-Αθανασίου Μπούρκερ

Επιβλέπων: Benoit Loppinet

(Σύμφωνα με το άρθρο 95, παρ. 3 του Ν. 4957/2022, ΦΕΚ 141 τ. Α΄/21.7.2022)

Την Τρίτη 5 Νοεμβρίου 2024 και ώρα 14:00 στην αίθουσα Τηλεκπαίδευσης Ε130 του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών του Πανεπιστημίου Κρήτης, θα γίνει η δημόσια παρουσίαση και υποστήριξη της Διδακτορικής Διατριβής του υποψήφιου διδάκτορος του Τμήματος Επιστήμης και Μηχανικής Υλικών κ. Νικολάου-Αθανασίου Μπούρκερ, με θέμα:

«Rheology and Μicrorheology at Ηigh Pressures»

In this dissertation we report experimental investigations of the dynamics, the phase and flow behavior of three systems, Organoclay, Supramolecular organogels, and gelatin. They are gelling dispersions. They form weak solids despite the low volume fraction. Of-ten out of equilibrium, such gels are sensitivity to weak perturbations and show strong dependence on the preparation and environmental conditions or external fields. Their flow behaviors and controls at given environmental conditions (pressure, temperature, humidity etc.) are of broad interest and valuable in multiple applications (energy, food and polymer industry).

We use scattering, rheology and microrheology to probe the dynamics, the linear and non-linear viscoelastic responses. Particular attention is given to high pressure (HP) conditions, as it is not much reported. Light scattering based passive HP-microrheology was developed and used to measure linear viscoelasticity. HP-shear rheology was also used for flow curves. When needed complementary structural characterization was per-formed through spectroscopy techniques and rheo – SAS (light and x-ray).

In organoclay dispersions (Ch. 3,4,5) we explore the effects of preparation treatment and we propose efficient ways to control the rheology and structure (clay exfoliation) through the construction of phase diagrams in clay concentration, homogenization temperature and water content space. We established shear history protocols and effectively tuned their mechanical properties without affecting much the structure. We monitor the evolution of organoclay dispersions and a model oil continuous drilling fluid at different pressures and aging.

We study the linear viscoelastic response and we construct phase diagrams of supramolecular organogels, (EHUT) at pressure, temperature and concentration (Ch. 6,7). We elucidate the effect of pressure and temperature on the linear viscoelasticity and attribute it to small variation in the self-assembly.

We study the effect of pressure (and concentration) on sol-gel transition of gelatin solutions (Ch. 8). We established that the gelation time decreases with increasing pressure, i.e., gelation speeds up. It is governed by the distance to the collagen denaturation temperature, known to increase with pressure by 0.04 K/Mpa.

Παρουσίαση Μεταπτυχιακής Διπλωματικής Εργασίας της κ. Νεράϊντας Πετράι

29 Οκτωβρίου 2024

ΠΑΝΕΠΙΣΤΗΜΙΟ ΚΡΗΤΗΣ

ΤΜΗΜΑ ΕΠΙΣΤΗΜΗΣ ΚΑΙ ΜΗΧΑΝΙΚΗΣ ΥΛΙΚΩΝ

 ΠΑΡΟΥΣΙΑΣΗ ΜΕΤΑΠΤΥΧΙΑΚΗΣ ΔΙΠΛΩΜΑΤΙΚΗΣ ΕΡΓΑΣΙΑΣ

 Τίτλος

«Functionalized Electrospun Nanofibrous Membranes with Antimicrobial Activity for Wound Healing»  

της Νεράϊντα Πετράι

μεταπτυχιακής φοιτήτριας του Τμήματος Επιστήμης και Μηχανικής Υλικών του Πανεπιστημίου Κρήτης

 Επιβλέπουσα Καθηγήτρια: Μαρία Χατζηνικολαΐδου

Δευτέρα 4 Νοεμβρίου 2024 Ώρα 10:00

H παρουσίαση θα πραγματοποιηθεί στην αίθουσα Τηλε-εκπαίδευσης (Ε130), στο κτήριο του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών, του Πανεπιστημίου Κρήτης

Abstract

Chronic wounds affect a significant percentage of the world population suffering from serious diseases. Therefore, there is a growing interest in the development of tissue-engineered scaffolds from natural and synthetic biomaterials to mimic natural skin. Researchers have attempted to functionalize the scaffolds with bioactive molecules to resist the bacterial infections that often develop on impaired wounds. Curcumin (Cur) has been reported to promote wound healing due to its many biological activities. Recently, the electrospraying technique has emerged for precise deposition of bioactive molecules into scaffolds to improve therapeutic outcomes. In this study, we aimed to produce scaffolds for wound healing and endow them with antibacterial properties to promote the healing of impaired wounds. Toward this end, we fabricated four types of membranes, poly(vinyl alcohol) PVA and PVA/kappa carrageenan (KC) using the electrospinning method and PVA/KC/Cur5, PVA/KC/Cur20, in which the PVA/KC membranes were coated with two different concentrations of Cur by electrospraying. All membranes showed low cytotoxicity, good cell adhesion, capability of enabling cells to produce collagen, and an adequate degradation rate for wound healing applications. Antibacterial studies showed that both Cur-loaded membranes increased antibacterial efficacy against both types of bacteria, Escherichia coli and Staphylococcus aureus, compared to PVA and PVA/KC membranes. Overall, these results suggest that coating Cur on the PVA/KC membranes using the electrospraying method is a potential therapeutic strategy for wound healing.

Παρουσίαση πτυχιακής εργασίας του κ. Παναγιώτη Βουβόπουλου

24 Οκτωβρίου 2024

Ηράκλειο 23 Οκτωβρίου 2024

Η ΠΑΡΟΥΣΙΑΣΗ ΔΙΠΛΩΜΑΤΙΚΗΣ ΕΡΓΑΣΙΑΣ

Του φοιτητή Παναγιώτη Βουβόπουλου,

θα γίνει την

Τρίτη 29/10/2024 και ώρα 12:15

στην αίθουσα Β2 στο κτήριο του τμήματος Χημείας

Θέμα Διπλωματικής:

«Study on the Release of Pharmaceutical Dipeptides from Peptide Hydrogels»

Διμελής Επιτροπή: Άννα Μητράκη, Μαρία Βαμβακάκη

Abstract:

This thesis focuses on the study and characterization of peptide sequences that self-assemble into fibrils forming hydrogel networks and their ability to act as reservoirs for encapsulation and controlled release of pharmaceutical molecules. Specifically, fluorenylmethyloxycarbonyl- di- phenylalanine or Fmoc-diphenylalanine, (Fmoc-FF) peptide hydrogels have been investigated for their ability to entrap and release drugs. The drug release capabilities of these peptide-based hydrogels have been explored using Bortezomib (BTZ) as a model pharmaceutical. Bortezomib (BTZ, N-pyrazino-Phe-BoroLeu) is a novel and selective proteasome inhibitor that disrupts the ubiquitin-proteasome pathway, crucial for degrading intracellular proteins; it is approved by FDA for treating multiple myeloma and other types of cancers. To ensure the system's functionality, experiments involving protocol development, identifying drug concentration, and removing background interference, -which is crucial for the accurate assessment of the release kinetics and biological activity of BTZ, have been carried out. Additionally, FESEM imaging was used to visually verify the structural integrity and fibril formations of the Fmoc-FF+BTZ system. These studies were complemented by spectroscopic methods, namely UV-Vis spectroscopy to monitor the release kinetics of BTZ, with the ultimate goal of achieving controlled release to avoid repeated administration via injection.

Παρουσίαση πτυχιακής εργασίας της κ. Δήμητρας – Κωνσταντίνας Μπομποδάκη

23 Οκτωβρίου 2024

Ηράκλειο 23 Οκτωβρίου 2024

Η ΠΑΡΟΥΣΙΑΣΗ ΤΗΣ ΠΤΥΧΙΑΚΗΣ ΕΡΓΑΣΙΑΣ

Της φοιτήτριας Δήμητρας - Κωνσταντίνας Μπομποδάκη,

θα γίνει την

Πέμπτη 31/10/2024 και ώρα 12:00

στην αίθουσα τηλεεκπαίδευσης Ε130 στο κτήριο του τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών

Θέμα Διπλωματικής:

«Θεωρητική μελέτη της προσρόφησης άνθρακα σε επιφάνειες οξειδίου του ψευδαργύρου»

«Theoretical study of carbon adsorption on zinc oxide surfaces»

Διμελής Επιτροπή: Ιωάννης Ρεμεδιάκης, Γεώργιος Κοπιδάκης

Abstract:

We employ first-principles computer simulations based on Density-Functional Theory (DFT) to study the various modifications of ZnO, including zincblende, wurtzite and rocksalt structures. For each system, we calculate the minimum-energy lattice parameters and perform a thorough investigation of the computational parameters of the problem. We then move to ZnO surfaces and calculate their electronic structure as well as their surface energy. Finally, we introduce carbon atoms on these surfaces in order to simulate carbon-surface-doped ZnO, a material that has been extensively studied for photocatalytic applications.

Παρουσίαση πτυχιακής εργασίας της κ. Άντζελας Νότη

23 Οκτωβρίου 2024

Ηράκλειο 23 Οκτωβρίου 2024

Η ΠΑΡΟΥΣΙΑΣΗ ΠΤΥΧΙΑΚΗΣ ΕΡΓΑΣΙΑΣ

Της φοιτήτριας Άντζελας Νότη,

θα γίνει την

Τρίτη 29/10/2024 και ώρα 11:15

στην αίθουσα Β2 στο κτήριο του τμήματος Χημείας

Θέμα Πτυχιακής Εργασίας:

«Study of hydrogel formation from unprotected dipeptides and applications»

Διμελής Επιτροπή: Άννα Μητράκη, Μαρία Βαμβακάκη

Abstract:

Peptide sequences have the ability to self-assemble into fibrils that form hydrogels, particularly when they carry protective groups such as Fmoc (fluorenyl-methoxycarbonyl) at the N-terminus. These hydrogels can function as reservoirs for the encapsulation and controlled release of pharmaceutical compounds. However, the presence of protective groups often raises concerns about their potential application, as questions arise regarding the safety of these groups.

This thesis focuses on the study and characterization of unprotected dipeptide sequences that self-assemble into fibrils forming hydrogel networks and their applications. Specifically, Isoleucine-Phenylalanine and Phenylalanine-Isoleucine, Ile-Phe and Phe-Ile or IF and FI dipeptide have been previously investigated for their ability to form hydrogels under physiological buffer conditions. In the present work we investigated whether hydrogel formation can occur using the two-solvent system, i.e. dissolving the peptide in a “good” solvent and inducing self-assembly by adding a “bad” solvent. In cases where hydrogels were formed, FESEM and Stereomicroscope were used to visually verify the structural integrity and fibril formations of the dipeptides. Hydrogels were formed using 30% HFIP as a “good” solvent, which makes them unsuitable for biomedical applications; however, HFIP is an optimal solvent for electrospinning. As a result, we explored the use of electrospinning to form membranes suitable for various applications since they do not retain the solvent. FESEM images were used to examine the surface morphology of the membrane; therefore, “proof-of-principle” was made, and further conditions remain to be explored in the future.

Παρουσίαση Μεταπτυχιακής Διπλωματικής Εργασίας του κ. Χαράλαμπου Γωνιωτάκη

21 Οκτωβρίου 2024

ΠΑΝΕΠΙΣΤΗΜΙΟ ΚΡΗΤΗΣ

ΤΜΗΜΑ ΕΠΙΣΤΗΜΗΣ ΚΑΙ ΜΗΧΑΝΙΚΗΣ ΥΛΙΚΩΝ

ΠΑΡΟΥΣΙΑΣΗ ΜΕΤΑΠΤΥΧΙΑΚΗΣ ΔΙΠΛΩΜΑΤΙΚΗΣ ΕΡΓΑΣΙΑΣ

 Τίτλος

«Development of AgI-AgPO3 Glass Microwire Based Photoactuators»  

του Χαράλαμπου Γωνιωτάκη

μεταπτυχιακού φοιτητή του Τμήματος Επιστήμης και Μηχανικής Υλικών του Πανεπιστημίου Κρήτης

 Επιβλέπων: Εμμανουήλ Στρατάκης

Παρασκευή 25 Οκτωβρίου 2024, Ώρα 10:00

H παρουσίαση θα πραγματοποιηθεί στην αίθουσα Τηλε-εκπαίδευσης (Ε130), στο κτήριο του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών, του Πανεπιστημίου Κρήτης

Abstract

Over the years significant scientific attention has been given towards the design of advanced photoactuating architectures as they are important elements for various optical tweezers, grippers, and soft robot applications. Most of the currently available photoactuators, rely on the existence of a free-space illumination pathway from the light sources to the device or on the employment of bendable optical fibers, while consisting of two or more elements, i.e. the photoactuating material and the substrate. Herein, we report on a facile method of preparing single-component pristine microwires (MWs) that exhibit photoactuating features upon utilizing a soft phosphate glass doped with silver nanoparticles (AgNPs), without the need of any additional photoactuating element. The developed photoactuators exhibited bending angles of around 110°, within a couple of seconds. In addition, we have fabricated double-component polymer-coated phosphate glass MWs photoactuators, upon employing PDMS coatings on the surface of the so-formed glass MWs. The introduction of the polymer component boosts the bending angle of the photoactuating device to over 200° within the a few seconds upon modest laser irradiation. The presence of AgNPs within the glass MWs, play a key role on the remarkable performance of the developed photoactuators, both in terms of actuating angles as well as of the respective response times, since they assist on the effective transmission of laser irradiation energy to thermal energy. The fabrication method reported here appears promising for the development of high-performance and low-cost free-space, as well as fiber-based photoactuators.

Καλωσόρισμα πρωτοετών φοιτητών/τριών

16 Οκτωβρίου 2024

Ιδρυματικά μαθήματα Κέντρου Γραφής

16 Οκτωβρίου 2024