Functionalization of Polycaprolactone Electrospun Osteoplastic Scaffolds with Fluorapatite and Hydroxyapatite Nanoparticles: Biocompatibility Comparison of Human Versus Mouse Mesenchymal Stem Cells

A capability for effective tissue reparation is a living requirement for all multicellular organisms. Bone exits as a precisely orchestrated balance of bioactivities of bone forming osteoblasts and bone resorbing osteoclasts. The main feature of osteoblasts is their capability to produce massive extracellular matrix enriched with calcium phosphate minerals. Hydroxyapatite and its composites represent the most common form of bone mineral providing mechanical strength and significant osteoinductive properties. Herein, hydroxyapatite and fluorapatite functionalized composite scaffolds based on electrospun polycaprolactone have been successfully fabricated. Physicochemical properties, biocompatibility and osteoinductivity of generated matrices have been validated. Both the hydroxyapatite and fluorapatite containing polycaprolactone composite scaffolds demonstrated good biocompatibility towards mesenchymal stem cells. Moreover, the presence of both hydroxyapatite and fluorapatite nanoparticles increased scaffolds’ wettability. Furthermore, incorporation of fluorapatite nanoparticles enhanced the ability of the composite scaffolds to interact and support the mesenchymal stem cells attachment to their surfaces as compared to hydroxyapatite enriched composite scaffolds. The study of osteoinductive properties showed the capacity of fluorapatite and hydroxyapatite containing composite scaffolds to potentiate the stimulation of early stages of mesenchymal stem cells’ osteoblast differentiation. Therefore, polycaprolactone based composite scaffolds functionalized with fluorapatite nanoparticles generates a promising platform for future bone tissue engineering applications.     

Epilepsy associated with autism and attention deficit hyperactivity disorder: Is there a genetic link?

Autism Spectrum Disorders (ASDs) and Attention Deficit and Hyperactivity Disorder (ADHD) are the most common comorbid conditions associated with childhood epilepsy. The co-occurrence of an epilepsy/autism phenotype or an epilepsy/ADHD phenotype has a complex and heterogeneous pathogenesis, resulting from several altered neurobiological mechanisms involved in early brain development, and influencing synaptic plasticity, neurotransmission and functional connectivity. Rare clinically relevant chromosomal aberrations, in addition to environmental factors, may confer an increased risk for ASDs/ADHD comorbid with epilepsy. The majority of the candidate genes are involved in synaptic formation/remodeling/maintenance (NRX1, CNTN4, DCLK2, CNTNAP2, TRIM32, ASTN2, CTNTN5, SYN1), neurotransmission (SYNGAP1, GABRG1, CHRNA7), or DNA methylation/chromatin remodeling (MBD5). Two genetic disorders, such as Tuberous sclerosis and Fragile X syndrome may serve as models for understanding the common pathogenic pathways leading to ASDs and ADHD comorbidities in children with epilepsy, offering the potential for new biologically focused treatment options.     

Alopecia areata. How not to miss Satoyoshi syndrome?

Satoyoshi syndrome is a multisystem disorder of suspected autoimmune etiology, characterized predominantly by alopecia, muscle spasms and diarrhea. Antinuclear antibodies are present in 60% of patients. The syndrome primarily affects girls and young women. Trichoscopy shows regularly distributed yellow dots, indistinguishable from typical alopecia areata. The condition may be easily misdiagnosed and treated as alopecia areata. On the basis of an in‐depth analysis of all published cases we developed diagnostic criteria for Satoyoshi syndrome. We also suggest that two subtypes of the disorder should be distinguished, the ANA‐positive Satoyoshi syndrome with generally good response to systemic glucocorticosteroid therapy and the ANA‐negative Satoyoshi with less favorable prognosis. In our opinion all patients will alopecia areata (in particular alopecia totalis) should be inquired about muscle spasms and diarrhea and tested for antinuclear antibodies to decrease the risk of missing Satoyoshi syndrome.     

Pulmonary nodules and nodular scleritis in a teenager with superficial granulomatous pyoderma gangrenosum

Superficial granulomatous pyoderma gangrenosum, a rare variant of pyoderma gangrenosum, has been considered to be the most benign form of the disease. We present the case of a 15‐year‐old boy with pulmonary involvement and nodular scleritis associated with this unusual type of pyoderma gangrenosum and discuss its differential diagnosis.