Pregnancy outcome following hematopoietic cell transplantation for thalassemia major

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Consensus on COVID‐19 Vaccination in Pediatric Oncohematological Patients, on Behalf of Infectious Working Group of Italian Association of Pediatric Hematology Oncology

Vaccines represent the best tool to prevent the severity course and fatal consequences of the pandemic by the new Coronavirus 2019 infection (SARS‐CoV‐2). Considering the limited data on vaccination of pediatric oncohematological patients, we developed a Consensus document to support the Italian pediatric hematological oncological (AIEOP) centers in a scientifically correct communication with families and patients and to promote vaccination. The topics of the Consensus were: SARS‐CoV‐2 infection and disease (COVID‐19) in the pediatric subjects; COVID‐19 vaccines (type, schedule); who and when to vaccinate; contraindications and risk of serious adverse events; rare adverse events; third dose and vaccination after COVID‐19; and other general prevention measures. Using the Delphi methodology for Consensus, 21 statements and their corresponding rationale were elaborated and discussed with the representatives of 31 centers, followed by voting. A high grade of Consensus was obtained on topics such as the potential risk of severe COVID‐19 outcome in pediatric oncohematological patients, the need for vaccination as a preventative measure, the type, schedule and booster dose of vaccine, the eligibility of the patients for vaccination, and the timing, definition, and management of contraindications and serious adverse events, and other general prevention measures. All 21 of the statements were approved. This consensus document highlights that children and adolescents affected by hematological and oncological diseases are a fragile category. Vaccination plays an important role to prevent COVID‐ 19, to permit the regular administration of chemotherapy or other treatments, to perform control visits and hospital admissions, and to prevent treatment delays

Microfabrication of a biomimetic arcade-like electrospun scaffold for cartilage tissue engineering applications

Designing and fabricating hierarchical geometries for tissue engineering (TE) applications is the major challenge and also the biggest opportunity of regenerative medicine in recent years, being the in vitro recreation of the arcade-like cartilaginous tissue one of the most critical examples due to the current inefficient standard medical procedures and the lack of fabrication techniques capable of building scaffolds with the required architecture in a cost and time effective way. Taking this into account, we suggest a feasible and accurate methodology that uses a sequential adaptation of an electrospinning-electrospraying set up to construct a system comprising both fibres and sacrificial microparticles. Polycaprolactone (PCL) and polyethylene glycol were respectively used as bulk and sacrificial biomaterials, leading to a bi-layered PCL scaffold which presented not only a depth-dependent fibre orientation similar to natural cartilage, but also mechanical features and porosity compatible with cartilage TE approaches. In fact, cell viability studies confirmed the biocompatibility of the scaffold and its ability to guarantee suitable cell adhesion, proliferation and migration throughout the 3D anisotropic fibrous network. Additionally, likewise the natural anisotropic cartilage, the PCL scaffold was capable of inducing oriented cell-material interactions since the morphology, alignment and density of the chondrocytes changed relatively to the specific topographic cues of each electrospun layer.publishe

Adipose-Derived Mesenchymal Stem Cells in the Use of Cartilage Tissue Engineering: The Need for a Rapid Isolation Procedure

Mesenchymal stem cells (MSCs) have shown much promise with respect to their use in cartilage tissue engineering. MSCs can be obtained from many different tissue sources. Among these, adipose tissue can provide an abundant source of adipose-derived mesenchymal stem cells (ADMSCs). The infrapatellar fat pad (IFP) is a promising source of ADMSCs with respect to producing a cartilage lineage. Cell isolation protocols to date are time-consuming and follow conservative approaches that rely on a long incubation period of 24-48 hours. The different types of ADMSC isolation techniques used for cartilage repair will be reviewed and compared with the view of developing a rapid one-step isolation protocol that can be applied in the context of a surgical procedure

Concise review: Human articular cartilage repair: Sources and detection of cytotoxicity and genotoxicity in photo-crosslinkable hydrogel bioscaffolds

Three-dimensional biofabrication using photo-crosslinkable hydrogel bioscaffolds has the potential to revolutionize the need for transplants and implants in joints, with articular cartilage being an early target tissue. However, to successfully translate these approaches to clinical practice, several barriers must be overcome. In particular, the photo-crosslinking process may impact on cell viability and DNA integrity, and consequently on chondrogenic differentiation. In this review, we primarily explore the specific sources of cellular cytotoxicity and genotoxicity inherent to the photo-crosslinking reaction, the methods to analyze cell death, cell metabolism, and DNA damage within the bioscaffolds, and the possible strategies to overcome these detrimental effects

Design, Fabrication and Validation of a Precursor Pulsed Electromagnetic Field Device for Bone Fracture Repair

Pulsed electromagnetic field (PEMF) stimulation has been utilized in the medical field since the early 20th century. A number of therapeutic devices have been developed for the treatment of bone fractures and other medical applications. Most of these devices are backed by limited quantitative evidence. In this paper we present the development of a PEMF device for the purposes of determining, through in vitro experimentation, the exposure parameters required to give the most optimal fracture repair. Following electromagnetic field characterization, the device was shown to match well with computational field simulations. The exposure system has been validated through adipose-derived stem cell viability studies with an exposure frequency of 5 Hz and an intensity of 1.1 mT, for a duration of seven days at 30 minutes per day. Under the specific field characteristics chosen, the fatty-tissue derived stem cell proliferation was not hindered and in fact was stimulated ( 0. 025 < P < 0.01) by the PEMF exposure. With continued experimentation of numerous exposure conditions at the cellular scale, it will be possible to quantitatively determine the optimal exposure conditions required to produce the most rapid fresh fracture repair. Following this, there is significant potential for development of an optimized wearable device suitable for enhancing repair of all types of bone fractures

Protocols for Culturing and Imaging a Human Ex Vivo Osteochondral Model for Cartilage Biomanufacturing Applications

Cartilage defects and diseases remain major clinical issues in orthopaedics. Biomanufacturing is now a tangible option for the delivery of bioscaffolds capable of regenerating the deficient cartilage tissue. However, several limitations of in vitro and experimental animal models pose serious challenges to the translation of preclinical findings into clinical practice. Ex vivo models are of great value for translating in vitro tissue engineered approaches into clinically relevant conditions. Our aim is to obtain a viable human osteochondral (OC) model to test hydrogel-based materials for cartilage repair. Here we describe a detailed step-by-step framework for the generation of human OC plugs, their culture in a perfusion device and the processing procedures for histological and advanced microscopy imaging. Our ex vivo OC model fulfils the following requirements: the model is metabolically stable for a relevant culture period of 4 weeks in a perfusion bioreactor, the processing procedures allowed for the analysis of 3 different tissues or materials (cartilage, bone and hydrogel) without compromising their integrity. We determined a protocol and the settings for a non-linear microscopy technique on label free sections. Furthermore, we established a clearing protocol to perform light sheet-based observations on the cartilage layer without the need for tedious and destructive histological procedures. Finally, we showed that our OC system is a clinically relevant in terms of cartilage regeneration potential. In conclusion, this OC model represents a valuable preclinical ex vivo tool for studying cartilage therapies, such as hydrogel-based bioscaffolds, and we envision it will reduce the number of animals needed for in vivo testing

Dkc1 overexpression induces a more aggressive cellular behavior and increases intrinsic ribosomal activity in immortalized mammary gland cells

Dyskerin is a nucleolar protein involved in the small nucleolar RNA (snoRNA)-guided pseudouridylation of specific uridines on ribosomal RNA (rRNA), and in the stabilization of the telomerase RNA component (hTR). Loss of function mutations in DKC1 causes X-linked dyskeratosis congenita, which is characterized by a failure of proliferating tissues and increased susceptibility to cancer. However, several tumors show dyskerin overexpression. We observed that patients with primary breast cancers with high dyskerin levels are more frequently characterized by shorter survival rates and positive lymph node status than those with tumors with a lower dyskerin expression. To functionally characterize the effects of high dyskerin expression, we generated stably overexpressing DKC1 models finding that increased dyskerin levels conferred a more aggressive cellular phenotype in untransformed immortalized MCF10A cells. Contextually, DKC1 overexpression led to an upregulation of some snoRNAs, including SNORA67 and a significantly increased U1445 modification on 18S rRNA, the known target of SNORA67. Lastly, we found that dyskerin overexpression strongly enhanced the synthetic activity of ribosomes increasing translational efficiency in MCF10A. Altogether, our results indicate that dyskerin may sustain the neoplastic phenotype from an early stage in breast cancer endowing ribosomes with an augmented translation efficiency

Characterization of Polycaprolactone Nanohydroxyapatite Composites with Tunable Degradability Suitable for Indirect Printing

Degradable bone implants are designed to foster the complete regeneration of natural tissue after large-scale loss trauma. Polycaprolactone (PCL) and hydroxyapatite (HA) composites are promising scaffold materials with superior mechanical and osteoinductive properties compared to the single materials. However, producing three-dimensional (3D) structures with high HA content as well as tuneable degradability remains a challenge. To address this issue and create homogeneously distributed PCL-nanoHA (nHA) scaffolds with tuneable degradation rates through both PCL molecular weight and nHA concentration, we conducted a detailed characterisation and comparison of a range of PCL-nHA composites across three molecular weight PCLs (14, 45, and 80 kDa) and with nHA content up to 30% w/w. In general, the addition of nHA results in an increase of viscosity for the PCL-nHA composites but has little effect on their compressive modulus. Importantly, we observe that the addition of nHA increases the rate of degradation compared to PCL alone. We show that the 45 and 80 kDa PCL-nHA groups can be fabricated via indirect 3D printing and have homogenously distributed nHA even after fabrication. Finally, the cytocompatibility of the composite materials is evaluated for the 45 and 80 kDa groups, with the results showing no significant change in cell number compared to the control. In conclusion, our analyses unveil several features that are crucial for processing the composite material into a tissue engineered implant