Selection Criteria of Cord Blood Units for Platelet Gel Production: Proposed Directions from Hellenic Cord Blood Bank. Comment on Mallis et al. Short Term Results of Fibrin Gel Obtained from Cord Blood Units: A Preliminary in Vitro Study. Bioengineering 2019, 6, 66.

This article provides additional knowledge for cord blood platelet gel (CBPG) production. Recently, it has been shown that CBPG exerts beneficial properties in wound healing applications. CBPG is produced after a two-step centrifugation process, following the addition of calcium gluconate. Clinical-grade CBPG can be produced in public cord blood banks, worldwide. However, standardization of the CBPG production process must be established in order to reduce discrepancies that occurred due to different platelet gel preparations. This article aims to provide an update regarding the selection criteria of cord blood units (CBUs), and to provide evidence for the improvement of the CBPG production process. (Comment on "Short Term Results of Fibrin Gel Obtained from Cord Blood Units: A Preliminary in Vitro Study" Bioengineering 2019, 6, 66).

Short Term Results of Fibrin Gel Obtained from Cord Blood Units: A Preliminary in Vitro Study.

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.

Non-Inherited Maternal Antigens Identify Acceptable HLA Mismatches: A New Policy for the Hellenic Cord Blood Bank.

BACKGROUND: During pregnancy, the maternal-fetal contact may lead to the development of tolerance against the maternal human leukocyte antigen (HLA) that is not inherited by the fetus. These non-inherited maternal antigens (NIMAs) define acceptable HLA mismatches; therefore, the number of HLA phenotypes that are suitable matches for patients who need a hematopoietic stem cell transplant could be increased. Cord blood unit (CBU) transplantations to patients mismatched for a HLA loci, but similar to the ΝΙΜAs of the CBU, have a prognosis similar to 6/6-matched ones. METHODS: The Hellenic Cord Blood Bank (HCBB) identified the maternal HLA of 380 cord blood donors, specifying the NIMA haplotypes of the related cryostored CBUs. RESULTS: The HCBB extended the pool of HLA phenotypes through the generation of unique virtual phenotypes (VPs). A "VP database" was set up, using Microsoft Office-Access™, in order to provide NIMA-matched CBUs for potential recipients. The effectiveness of VPs' matching was tested in 80 Greek patients. CONCLUSION: This methodology may contribute to the increase of the number of available CBUs for patients, in the case where there is no available CBU, or in case an additional one is needed. Through this method, the CBUs could be used faster and more effectively, rather than being cryostored for long periods of time.

Optimizing isolation culture and freezing methods to preserve Wharton's jelly's mesenchymal stem cell (MSC) properties: an MSC banking protocol validation for the Hellenic Cord Blood Bank.

BACKGROUND: Mesenchymal stem or stromal cells (MSCs) are a heterogeneous population that can be isolated from many tissues including umbilical cord Wharton's jelly (UC-WJ). Although initially limited in studies such as a hematopoietic stem cell transplantation adjuvant, an increasing number of clinical trials consider MSCs as a potential anti-inflammatory or a regenerative medicine agent. It has been proposed that creating a repository of MSCs would increase their availability for clinical applications. The aim of this study was to assess the optimal isolation and cryopreservation procedures to facilitate WJ MSC banking. STUDY DESIGN AND METHODS: Cells were isolated from UC-WJ using enzymatic digestion or plastic adhesion methods. Their isolation efficacy, growth kinetics, immunophenotype, and differentiation potential were studied, as well as the effects of freezing. Flow cytometry for common MSC markers was performed on all cases and differentiation was shown with histocytochemical staining. Finally, the isolation efficacy on cryopreserved WJ tissue fragments was tested. RESULTS: MSC isolation was successful using both isolation methods on fresh UC-WJ tissue. However, UC-WJ MSC isolation from frozen tissue fragments was impossible. Flow cytometry analysis revealed that only MSC markers were expressed on the surface of the isolated cells while differentiation assays showed that they were capable of trilinear differentiation. All the above characteristics were also preserved in isolated UC-WJ MSCs over the cryopreservation study period. CONCLUSION: These data showed that viable MSCs can only be isolated from fresh UC-WJ tissue, setting the foundation for clinical-grade banking.