Optimization of Suture-Free Laser-Assisted Vessel Repair by Solder-Doped Electrospun Poly(ε-caprolactone) Scaffold

Poor welding strength constitutes an obstacle in the clinical employment of laser-assisted vascular repair (LAVR) and anastomosis. We therefore investigated the feasibility of using electrospun poly(ε-caprolactone) (PCL) scaffold as reinforcement material in LAVR of medium-sized vessels. In vitro solder-doped scaffold LAVR (ssLAVR) was performed on porcine carotid arteries or abdominal aortas using a 670-nm diode laser, a solder composed of 50% bovine serum albumin and 0.5% methylene blue, and electrospun PCL scaffolds. The correlation between leaking point pressures (LPPs) and arterial diameter, the extent of thermal damage, structural and mechanical alterations of the scaffold following ssLAVR, and the weak point were investigated. A strong negative correlation existed between LPP and vessel diameter, albeit LPP (484 ± 111 mmHg) remained well above pathophysiological pressures. Histological analysis revealed that thermal damage extended into the medial layer with a well-preserved internal elastic lamina and endothelial cells. Laser irradiation of PCL fibers and coagulation of solder material resulted in a strong and stiff scaffold. The weak point of the ssLAVR modality was predominantly characterized by cohesive failure. In conclusion, ssLAVR produced supraphysiological LPPs and limited tissue damage. Despite heat-induced structural/mechanical alterations of the scaffold, PCL is a suitable polymer for weld reinforcement in medium-sized vessel ssLAVR

Micromorphological and Anatomical Characteristics of the Genus Chrysophthalmum Schultz Bip. (Asteraceae) Growing in Turkey

The genus Chrysophthalmum (Asteraceae) is represented by five species in the world. Three species of this genus are naturally grown in Turkey. The species growing in Turkey are C. montanum (DC.) Boiss., C. dichotomum Boiss. and Heldr. and C. gueneri Aytac and Anderb. Except C. montanum; the other species are endemic for Turkey. In the present study, micromorphological and anatomical characteristics of these species by using light microscopy (LM) and scanning electronmicroscopy (SEM) have been comparatively presented for the first time. Themicromorphological studies are related to trichomes and cypsela. In anatomical studies, crosssections of the stem, and leaf have been examined. In addition, to show stomatal distribution and anatomy on adaxial and abaxial leaves, surface sections of the leaves have been taken and stomatal index calculated. The features of stems, leaves, trichomes and cypsela have been found to be significant to distinguish the species. Mesophyll structure, number of vascular bundles in midrib, presence or absence of sclerenchymatous fibers in leaf, trichome types, presence or absence of pappus in cypsela, presence or absence of hair on cypsela surface are important diagnostic characters. A diagnostic key based on combined leaf, trichome and cypsela characteristics of the Chrysophthalmum species has been given