Ioanna Gontika

Dr. Ioanna Gontika

orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
4 June 2014 in Transfusion
Verified
Journal Article
Closed access
PDF file
TCTheofanis K Chatzistamatiou
Theofanis K Chatzistamatiou
APAndreas C. Papassavas
Andreas C. Papassavas
Efstathios MichalopoulosEfstathios Michalopoulos
Efstathios Michalopoulos
CGChristos Gamaloutsos
Christos Gamaloutsos
PANAGIOTIS MALLISPANAGIOTIS MALLIS
PANAGIOTIS MALLIS
CSCatherine Stavropoulos‐Giokas
Catherine Stavropoulos‐Giokas

5 March 2019 in Bioengineering
Verified
Journal Article
Open access
PDF file
VPVASSILIS PROTOGEROU
VASSILIS PROTOGEROU
Efstathios MichalopoulosEfstathios Michalopoulos
Efstathios Michalopoulos
PANAGIOTIS MALLISPANAGIOTIS MALLIS
PANAGIOTIS MALLIS
IGIoanna Gontika
Ioanna Gontika
ZDZetta Dimou
Zetta Dimou
CDCharalampos Deliveliotis
Charalampos Deliveliotis
Erectile dysfunction (ED) affects more than 30 million men; endothelial dysfunction plays a significant role in EDs pathogenesis. The aim of this study was to administer mesenchymal stem cells (MSC) derived from adipose tissue and platelet lysate (PL) into patients with erectile dysfunction. This pilot study enrolled eight patients with diagnosed ED. Patients enrolled were suffering from organic ED due to diabetes melitus, hypertension, hypercholesterolaemia, and Peyronie disease. The patients were distributed in 2 groups. Patients in group A received adipose derived mesenchymal stem cells (ADMSC) resuspended in PL while patients in group B received only PL. ADMSCs were isolated from patients’ adipose tissue and expanded. In addition, blood sampling was obtained from the patients in order to isolate platelet lysate. After the application of the above treatments, patients were evaluated with an International Index of Erectile Function (IIEF-5) questionnaire, penile triplex, and reported morning erections. After MSCs and PL administration, patients presented improved erectile function after 1 and 3 months of follow-up. A statistically significant difference was observed in the IIEF-5 score before and after administration of both treatments after the first month (p < 0.05) and the third month (p < 0.05). No statistically significant difference was observed in the IIEF-5 score between group A and B patients. All patients were characterized by improved penile triplex and increased morning erections. No severe adverse reactions were observed in any patient except a minor pain at the site of injection, which was in the limits of tolerability. The results of this study indicated the satisfactory use of MSCs and PL in ED. MSCs in combination with PL or PL alone seems to be very promising, especially without having the negative effects of the current therapeutic treatment.

2 August 2019 in Bioengineering
Verified
Journal Article
Open access
PDF file
PANAGIOTIS MALLISPANAGIOTIS MALLIS
PANAGIOTIS MALLIS
IGIoanna Gontika
Ioanna Gontika
ZDZETTA DIMOU
ZETTA DIMOU
EPEffrosyni Panagouli
Effrosyni Panagouli
JZJerome Zoidakis
Jerome Zoidakis
Efstathios MichalopoulosEfstathios Michalopoulos
Efstathios Michalopoulos
Background: Recent findings have shown that the fibrin gel derived from cord blood units (CBUs) play a significant role in wound healing and tissue regeneration. The aim of this study was to standardize the fibrin gel production process in order to allow for its regular use. Methods: CBUs (n = 200) were assigned to 4 groups according to their initial volume. Then, a two-stage centrifugation protocol was applied in order to obtain platelet rich plasma (PRP). The concentration of platelets (PLTs), white blood cells (WBCs) and red blood cells (RBCs) were determined prior to and after the production process. In addition, targeted proteomic analysis using multiple reaction monitoring was performed. Finally, an appropriate volume of calcium gluconate was used in PRP for the production of fibrin gel. Results: The results of this study showed that high volume CBUs were characterized by greater recovery rates, concentration and number of PLTs compared to the low volume CBUs. Proteomic analysis revealed the presence of key proteins for regenerative medicine. Fibrin gel was successfully produced from CBUs of all groups. Conclusion: In this study, low volume CBUs could be an alternative source for the production of fibrin gel, which can be used in multiple regenerative medicine approaches.

29 January 2022 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
Nikoleta BizymiNikoleta Bizymi
Nikoleta Bizymi
AAnthie Georgopoulou
Anthie Georgopoulou
NMNatalia Mastrogamvraki
Natalia Mastrogamvraki
AMAngelos Matheakakis
Angelos Matheakakis
IGIoanna Gontika
Ioanna Gontika
Helen PapadakiHelen Papadaki
Helen Papadaki
Myeloid-derived suppressor cells (MDSCs) represent a heterogeneous population of myeloid cells that suppress immune responses in cancer, infection, and trauma. They mainly act by inhibiting T-cells, natural-killer cells, and dendritic cells, and also by inducing T-regulatory cells, and modulating macrophages. Although they are mostly associated with adverse prognosis of the underlying disease entity, they may display positive effects in specific situations, such as in allogeneic hematopoietic stem cell transplantation (HSCT), where they suppress graft-versus-host disease (GVHD). They also contribute to the feto-maternal tolerance, and in the fetus growth process, whereas several pregnancy complications have been associated with their defects. Human umbilical cord blood (UCB) is a source rich in MDSCs and their myeloid progenitor cells. Recently, a number of studies have investigated the generation, isolation, and expansion of UCB-MDSCs for potential clinical application associated with their immunosuppressive properties, such as GVHD, and autoimmune and inflammatory diseases. Given that a significant proportion of UCB units in cord blood banks are not suitable for clinical use in HSCT, they might be used as a significant source of MDSCs for research and clinical purposes. The current review summarizes the roles of MDSCs in the UCB, as well as their promising applications.

1 March 2019 in Tissue Engineering Part A
Verified
Journal Article
Closed access
Michalis KatsimpoulasMichalis Katsimpoulas
Michalis Katsimpoulas
LMLucrezia Morticelli
Lucrezia Morticelli
IGIoanna Gontika
Ioanna Gontika
AKArtemis Kouvaka
Artemis Kouvaka
PANAGIOTIS MALLISPANAGIOTIS MALLIS
PANAGIOTIS MALLIS
Sotirios KorossisSotirios Korossis
Sotirios Korossis
Peripheral arterial disease causes blood vessel dysfunction that requires surgical intervention. Current surgical interventions employ synthetic or allogeneic vascular grafts, which offer biocompatible material solutions that are not able to regenerate or grow with the patient. Decellularized scaffolds have gained significant momentum in the past few years, since they have the potential to regenerate in the patient. The aim of this study was to investigate the effects of modified decellularization protocol on the biocompatibility and immunogenicity of allogeneic rat abdominal aorta in an orthotopic rat model. Native syngeneic Wistar (W) and allogeneic Dark Agouti (DA) aortas, together with decellularized allogeneic DA aortas, were assessed histologically, immunohistochemically, and biomechanically. The immunogenicity of the untreated and decellularized syngeneic and allogeneic grafts was assessed in W rats, implanted orthotopically. Following implantation for 6 weeks, the grafts were explanted and assessed for the presence of T cells and macrophages by immunohistochemistry, and for their biomechanical integrity and histoarchitecture. No obvious histoarchitectural differences were observed between the native W and DA aortas, with both presenting similar three-layered structures. Histological analysis of decellularized DA aortas did not reveal any remaining cells. Explanted native DA allografts showed media necrosis, partial elastic fiber degradation, and adventitia thickening, as well as infiltration by lymphocytes (CD3 + , CD4 + ) and macrophages (CD68+) in the adventitia. The explanted decellularized DA allografts indicated reduced immune injury compared to the explanted native DA allografts. The explanted native W syngeneic grafts showed a mild immune response, with an intact media and no lymphocyte infiltration. The explanted native DA allografts showed significantly lower collagen phase slope than the decellularized DA allografts before implantation, and significantly higher thickness than the explanted decellularized DA allografts. The results indicated that the modified decellularization protocol did not affect significantly the mechanical and histological properties of the native DA rat aorta. Overall, the immune response was improved by decellularization. Native DA allografts induced an adverse immune response in W rats, whereas syngeneic W grafts showed good tissue integration Impact Statement: The generation of a small-caliber arterial graft, utilizing a large vessel of a small animal, such as the aorta of the rat or rabbit, for clinical use in the peripheral arterial tree, can widen the options for arterial prostheses. This in vivo study demonstrated the ability of the decellularization protocol that was used to produce a noncytotoxic acellular small-caliber arterial graft, with sufficient biomechanical and biological integrity to withstand the demanding flow and pressure environment of the rat aorta. This work also demonstrated the superiority of the decellularized homograft over its intact counterpart, in terms of lower immunogenicity.

21 November 2018 in Bioengineering
Verified
Journal Article
Open access
PDF file
IGIoanna Gontika
Ioanna Gontika
Michalis KatsimpoulasMichalis Katsimpoulas
Michalis Katsimpoulas
EAEfstathios Antoniou
Efstathios Antoniou
AKAlkiviadis Kostakis
Alkiviadis Kostakis
Catherine Stavropoulos-GiokasCatherine Stavropoulos-Giokas
Catherine Stavropoulos-Giokas
Efstathios MichalopoulosEfstathios Michalopoulos
Efstathios Michalopoulos
Treatment of injuries to peripheral nerves after a segmental defect is one of the most challenging surgical problems. Despite advancements in microsurgical techniques, complete recovery of nerve function after repair has not been achieved. The purpose of this study was to evaluate the use of the decellularized human umbilical artery (hUA) as nerve guidance conduit. A segmental peripheral nerve injury was created in 24 Sprague–Dawley rats. The animals were organized into two experimental groups with different forms of repair: decellularized hUA (n = 12), and autologous nerve graft (n = 12). Sciatic faction index and gastrocnemius muscle values were calculated for functional recovery evaluation. Nerve morphometry was used to analyze nerve regeneration. Results showed that decellularized hUAs after implantation were rich in nerve fibers and characterized by improved Sciatic Functional index (SFI) values. Decellularized hUA may support elongation and bridging of the 10 mm nerve gap.