In vitro release and In vivo biocompatibility studies of biomimetic multilayered alginate-chitosan/β-TCP scaffold for osteochondral tissue

Biomimetic three-layered monolithic scaffold (TLS) intended for the treatment of osteocondral defects was prepared by using alginate, chitosan and β-tricalcium phosphate (β-TCP) to study drug release behavior of the alternative drug delivery system and to investigate the therapeutic efficacy of the scaffold. Dexamethasone sodium phosphate (Dex) as a model drug was incorporated into the scaffold by solvent sorption method and in vitro release studies were conducted. In addition, the scaffold was implanted into the defects formed in the trochlea of Sprague–Dawley rats to assess the healing potential of the TLS on the osteochondral defect against reference Maioregen® comparatively. The release studies showed that after an initial burst at 3rd h, dexamethasone is released slowly during a 72-h period. In vivo studies indicated that the TLS has good tissue biocompatibility and biodegradation rate and showed better results during osteochondral healing process compared to the reference. All results demonstrated that the alginate-chitosan/β-TCP scaffold could be evaluated as a good candidate for osteochondral tissue applications.     

Determining host factors contributing to disease severity in a family cluster of 29 hospitalized SARS‐CoV‐2 patients: Could genetic factors be relevant in the clinical course of COVID‐19?

In this study, we report a large family cluster consisting of 29 genetically related patients hospitalized with coronavirus disease‐2019 (COVID‐19). We sought to determine the clinical characteristics relevant to the clinical course of COVID‐19 by comparing the family cluster to unrelated patients with SARS‐CoV‐2 infection so that the presence of potential determinants of disease severity, other than traditional risk factors previously reported, could be investigated. Twenty‐nine patient files were investigated in group 1 and group 2 was created with 52 consecutive patients with COVID‐19 having age and gender compatibility. The virus was detected for diagnosis. The clinical, laboratory and imaging features of all patients were retrospectively screened. Disease course was assessed using records regarding outcome from patient files retrospectively. Groups were compared with respect to baseline characteristics, disease severity on presentation, and disease course. There was no difference between the two groups in terms of comorbidity and smoking history. In terms of inhospital treatment, use differed not significantly between two groups. We found that all 29 patients in the group 1 had severe pneumonia, 18 patients had severe pneumonia. Hospitalization rates, length of hospital stay, and transferred to intensive care unit were found to be statistically significantly higher in the group 1. In the present study, COVID‐19 cases in the large family cluster were shown to have more severe disease and worse clinical course compared with consecutive patients with COVID‐19 presenting to the same time. We believe further studies into potential genetic mechanisms of host susceptibility to COVID‐19 should include such family clusters.