Preclinical assessment on neuronal regeneration in the injury-related microenvironment of graphene-based scaffolds.

As the application of graphene nanomaterials gets increasingly attractive in the field of tissue engineering and regenerative medicine, the long-term evaluation is necessary and urgent as to their biocompatibility and regenerative capacity in different tissue injuries, such as nerve, bone, and heart. However, it still remains controversial about the potential biological effects of graphene on neuronal activity, especially after severe nerve injuries. In this study, we establish a lengthy peripheral nerve defect rat model and investigate the potential toxicity of layered graphene-loaded polycaprolactone scaffold after implantation during 18 months in vivo. In addition, we further identify possible biologically regenerative effects of this scaffold on myelination, axonal outgrowth, and locomotor function recovery. It is confirmed that graphene-based nanomaterials exert negligible toxicity and repair large nerve defects by dual regulation of Schwann cells and astroglia in the central and peripheral nervous systems. The findings enlighten the future of graphene nanomaterial as a key type of biomaterials for clinical translation in neuronal regeneration.

[Using infrared thermal asymmetry analysis for objective assessment of the lesion of facial nerve function].

The skin temperature distribution of a healthy human body exhibits a contralateral symmetry. Some lesions of facial nerve function are associated with an alteration of the thermal distribution of the human body. Since the dissipation of heat through the skin occurs for the most part in the form of infrared radiation, infrared thermography is the method of choice to capture the alteration of the infrared thermal distribution. This paper presents a new method of analysis of the thermal asymmetry named effective thermal area ratio, which is a product of two variables. The first variable is mean temperature difference between the specific facial region and its contralateral region. The second variable is a ratio, which is equal to the area of the abnormal region divided by the total area. Using this new method, we performed a controlled trial to assess the facial nerve function of the healthy subjects and the patients with Bell's palsy respectively. The results show: that the mean specificity and sensitivity of this method are 0.90 and 0.87 respectively, improved by 7% and 26% compared with conventional methods. Spearman correlation coefficient between effective thermal area ratio and the degree of facial nerve function is an average of 0.664. Hence, concerning the diagnosis and assessment of facial nerve function, infrared thermography is a powerful tool; while the effective ther mal area ratio is an efficient clinical indicator.

Assessment of right ventricular free wall longitudinal myocardial deformation using speckle tracking imaging in normal subjects.

To assess right ventricular free wall longitudinal myocardium deformation and examine the changes with normal age by speckle tracking imaging (STI), myocardial systolic peak strain (epsilon), systolic peak strain rate (SRs), early diastolic peak strain rate (SRe), late diastolic peak strain rate (SRa), the ratio of SRe/SRa were measured in the basal, middle and apical segments of right ventricular free wall in 75 healthy volunteers (age range: 21-71 y) by STI from the apical 4-chamber view. RV longitudinal strain and strain rate were highest in the basal segment of the free wall. Older subjects had lower early diastolic strain rate (SRe) than younger subjects, but they had higher late diastolic strain rate (SRa). A negative correlation between age and the ratio of SRe/SRa was found in all RV free wall segments (r=-0.466 - -0.614, P<0.01). It is concluded that RV diastolic strain rate changes with age and STI can be used for the study of RV myocardial deformation.