On the Effect of Soft Molecularly Imprinted Nanoparticles Receptors Combined to Nanoplasmonic Probes for Biomedical Applications

Soft, deformable, molecularly imprinted nanoparticles (nanoMIPs) were combined to nano-plasmonic sensor chips realized on poly (methyl methacrylate) (PMMA) substrates to develop highly sensitive bio/chemical sensors. NanoMIPs (dmean < 50 nm), which are tailor-made nanoreceptors prepared by a template assisted synthesis, were made selective to bind Bovine Serum Albumin (BSA), and were herein used to functionalize gold optical nanostructures placed on a PMMA substrate, this latter acting as a slab waveguide. We compared nanoMIP-functionalized non-optimized gold nanogratings based on periodic nano-stripes to optimized nanogratings with a deposited ultra-thin MIP layer (<100 nm). The sensors performances were tested by the detection of BSA using the same setup, in which both chips were considered as slab waveguides, with the periodic nano-stripes allocated in a longitudinal orientation with respect to the direction of the input light. Result demonstrated the nanoMIP-non optimized nanogratings showed superior performance with respect to the ultra-thin MIP-optimized nanogratings. The peculiar deformable character of the nano-MIPs enabled to significantly enhance the limit of detection (LOD) of the plasmonic bio/sensor, allowing the detection of the low femtomolar concentration of analyte (LOD ∼ 3 fM), thus outpassing of four orders of magnitude the sensitivies achieved so far on optimized nano-patterned plasmonic platforms functionalized with ultra-thin MIP layers. Thus, deformable nanoMIPs onto non-optimized plasmonic probes permit to attain ultralow detections, down to the quasi-single molecule. As a general consideration, the combination of more plasmonic transducers to different kinds of MIP receptors is discussed as a mean to attain the detection range for the selected application field.

Radiological Evaluation of Postsurgical Course of Perforators in Retrograde Posterior Tibial Fasciocutaneous Flaps for Distal Leg and Foot Defects

Background Mapping of vascular perforators by various methodologies have been described for planning of a variety of flaps in the lower limbs. We attempted to assess the changes in posterior tibial perforators after transfer of fasciocutaneous flaps for leg defects. Methods 20 patients with distal leg and foot defects were studied by computed tomography angiography (CTA) and preoperative audio Doppler to ascertain perforators of posterior tibial artery. Fasciocutaneous flaps were raised, based on these perforators, depending on the site and size of soft-tissue defects. The number of perforators and their distance from the medial malleolus were also studied. Postoperative CTA was performed on the 7th to 10th day, with emphasis on postoperative changes of the perforators on which the flaps were based. Results One to four posterior tibial perforators were found between 5 cm and 8 cm proximal to the medial malleolus. After flap transfer, the perforators could be traced to variable distance through the total length of the flap. The perforators formed small vascular loop in 12 patients, following retrograde posterior tibial flap transfer. The height of the loop, the number of such loops, the dilatation and tortuosity of the perforators, and their longitudinal orientation were studied in detail. Most of the findings can be explained by mechanical realignment of perforators as well as by the delay phenomenon associated with retrograde fasciocutaneous flaps. Conclusion It was concluded that the morphological changes associated with the perforators explained the vascular rationality and success of these flaps.

Collagen Fibres Orientation in the Bone Matrix around Dental Implants: Does the Implant’s Thread Design Play a Role?

The aim of this study was to analyse the influence of different thread shapes of titanium dental implant on the bone collagen fibre orientation (BCFO) around loaded implants. Twenty titanium dental implants, divided for thread shapes in six groups (A–F) were analysed in the present study. All implants were immediately loaded and left in function for 6 months before retrieval. The parameters evaluated under scanning electron microscope were the thread width, thread depth, top radius of curvature, flank angle, and the inter-thread straight section. Two undecalcified histological sections were prepared from each implant. Birefringence analysis using circularly polarized light microscopy was used to quantitively measure BCFO. For groups A–F, respectively, transverse BCFO was 32.7%, 24.1%, 22.3%, 18.2%, 32.4%, and 21.2%, longitudinal BCFO was 28.2%, 14.5%, 44.9%, 33.1%, 37.7%, and 40.2%. The percentage differences between transverse and longitudinal orientation were 4.50% (A), 9.60% (B), −22.60% (C), −14.90% (D), −5.30% (E), and −19.00% (F). Following loading, the amount of transverse and longitudinal BCFO were significantly influenced by the thread shape. The greater flank angles and narrower inter-thread sections of the “V” shaped and “concave” shaped implant threads of groups A and B, respectively, promoted the predominance of transverse BCFO, compared to groups C-F (p < 0.05). A narrow inter-thread straight section promotes transverse BCFO, as do “V” shaped and “concave” shaped threads, which can thus be considered desirable design for implant threads.

Experimental study on an alternative to suturing the laparotomy wound with a mesh thread

BACKGROUND: Incisional ventral hernias (IVH) in abdominal surgery remain relevant because the frequency of their formation after laparotomy reaches 10%30.7%. AIM: This study aimed to develop a method for the primary closure of a laparotomy wound via mesh endoprosthesis, which is superior to laparorrhaphy with traditional suture materials in terms of morphophysical properties. MATERIALS AND METHODS: Laparorrhaphy with a mesh thread was developed (Patent for invention RUS No 2714439 02/14/2020) as an alternative to preventive prosthetics with narrow indications to avoid herniation. An experimental work was conducted to investigate the wound process in the suture area on days 14 and 60 and determine the effectiveness and safety of the proposed method. RESULTS: Video laparoscopy data showed that no cases of adhesions were observed between the internal organs and the area of laparorrhaphy on days 14 and 60 of the postoperative period. Defects in the area of the application of sutures on the aponeurosis of the white line were absent. In the wound, the mesh thread fully integrated into the regenerating tissue, including at the site of the knot. The tissue also grew through the meshed cells. On day 14, the strength of the regenerating tissue with the sutured mesh thread was greater than that sutured without it (11.198 1.499, p 0.01). This finding was confirmed by the larger area of granulations and fibrosis in cases of mesh suture than that of the checkerwise-reinforcing suture, suture with a mesh thread, and suture with a strip of mesh endoprosthesis. Another peculiarity of the connective tissue newly formed in the area of the mesh endoprosthesis in the form of the mesh thread was that collagen fibrils were arranged concentrically. By contrast, the mesh strip had collagen fibrils arranged in a longitudinal orientation parallel to the endoprosthesis. On day 60 of the experiment, all the series showed signs of maturation of the connective tissue in the form of the predomination of fibrils in cellular elements and their compaction. The area of fibrosis and granulations still prevailed in cases of the mesh suture, where neocollagenogenesis in the cells of the endoprosthesis was more pronounced than that after the application of a reinforcing suture, a mesh thread, and a strip of mesh endoprosthesis. CONCLUSION: The absence of wound complications and negative impact on the surrounding tissues indicated the safety of using the mesh suture. The strengthened characteristics associated with the peculiarities of the wound process showed that the mesh suture was effective in preventing the occurrence of postoperative hernia. Therefore, this method could be used in clinical practice.

Variablity in vastus lateralis fiber type distribution, fiber size and myonuclear content along and the between legs

Human skeletal muscle characteristics such as fiber type composition, fiber size and myonuclear content are widely studied in clinical and sports related contexts. Being aware of the methodological and biological variability of the characteristics is a critical aspect in study design and outcome interpretation, but comprehensive data on the variability of morphological features in human skeletal muscle is currently limited. Accordingly, in the present study, m. vastus lateralis biopsies (10 per subject) from young and healthy individuals, collected in a systematic manner, were analyzed for various characteristics using immunohistochemistry (n=7) and SDS-PAGE (n=25). None of the analyzed parameters; fiber type % (FT%), type I and II CSA (fCSA), percentage fiber type area (fCSA%), myosin heavy chain composition (MyHC%), type IIX content, myonuclear content or myonuclear domain varied in a systematic manner longitudinally along the muscle or between the two legs. The average within subject coefficient of variation for FT%, fCSA, fCSA%, and MyHC% ranged between 13-18%, but was only 5% for fiber specific myonuclear content, which reduced the variability for myonuclear domain size to 11-12%. Pure type IIX fibers and type IIX MyHC were randomly distributed and present in <24% of the analyzed samples, with the average content being 0.1 and 1.1%, respectively. In conclusion, leg or longitudinal orientation does not seem to be an important aspect to consider when investigating human vastus lateralis characteristics. However, single muscle biopsies should preferably not be used when studying fiber type and fiber size related aspects given the notable sample to sample variability.

First record of intertidal oribatid mites (Acari, Oribatida) from the Canaries – a new species and its complete ontogeny

A new species of intertidal oribatid mites from Tenerife is described and its full ontogenetic development is given in detail. Thalassozetes canariensis sp. nov. can easily be distinguished from its congeners by its characteristic notogastral cuticular pattern showing loosely distributed irregular elevations, and its rectangular median sternal cavity. Based on morphology, Thalassozetes canariensis sp. nov. is most closely related to the Mediterranean T. riparius; both species share a small transversal band-like notogastral light spot and the longitudinal orientation of lyrifissure iad. The juvenile morphology of T. canariensis sp. nov. conforms basically to those of known Thalassozetes juveniles but there are discrepancies in certain aspects that require further research into all known species. This report of T. canariensis sp. nov. from Tenerife is the first record of an intertidal mite for the Canaries, and also for the Eastern Atlantic area. Further records of this species within the area may be expected.

Effect of Surface Treatment and Cutting Orientation to the Changes in Stents Surface Roughness

During the implantation process, an expandable balloon stent undergoes a change in mesh shape with a high strain rate. Permanent mesh shape changes to the stents indicate plastic deformation has occurred. On a micro-scale, plastic deformation has significant influence when interacting with the soft tissue of human blood vessels. This experimental study aims to investigate the effect of surface treatment and cutting orientation on the changes in surface roughness that definitely occurs when a stent deployed. To study the effect of surface treatment, two types of surface treatment were applied after surface polishing, i.e. etching and electropolishing. Surface polishing is carried out to enable microscopic observation. As for examining the effect of cutting orientation, the plate is cut in lateral and longitudinal orientation against the predicted-rolling direction of 316L sheet-type of stainless steel. An intermittent tensile test is conducted to obtain information about the changes in surface roughness. The surface observation is carried out three times on a similar surface of testpiece after reaching plastic deformation. The experimental study shows that the orientation of raw material has an insignificant effect on the changes in stent surface roughness. As for the surface treatments, electropolishing tended to decrease the tensile property of material.

Does longitudinal or transverse orientation of the ultrasound probe improve cannulation success in minimally invasive venous surgery: A multicentre randomised controlled trial

Objective This study evaluates the effect of transverse and longitudinal ultrasound transducer orientation on saphenous vein cannulation during endovenous ablation. Methods A single-blinded, multicentre, randomised controlled trial was performed in patients undergoing ultrasound-guided venous cannulation for saphenous ablation. The primary outcomes were overall cannulation success and time to successful cannulation. Results In total, 100 patients were assigned to parallel longitudinal orientation and transverse orientation groups. Cannulation success was 100%. There was no significant variation in time to cannulation detected between the transverse orientation and longitudinal orientation (85 s vs. 71 s, p = 0.314). Longitudinal orientation was associated with significantly fewer needle passes [median 3 (interquartile range 1–5) vs. 2 (interquartile range 1–3), p = 0.026] and less pain (median visual analogue scale score 1 vs. 2.5, p = 0.039) than those in the transverse orientation group. Conclusion This trial has shown that while longitudinal orientation is associated with less procedural pain it has no significant effect on time to target vein cannulation during endovenous ablation.

Electrochemical gradients are involved in regulating cytoskeletal patterns during epithelial morphogenesis in the Drosophila ovary

Background During Drosophila oogenesis, the follicular epithelium differentiates into several morphologically distinct follicle-cell populations. Characteristic bioelectrical properties make this tissue a suitable model system for studying connections between electrochemical signals and the organisation of the cytoskeleton. Recently, we have described stage-specific transcellular antero-posterior and dorso-ventral gradients of intracellular pH (pHi) and membrane potential (Vmem) depending on the asymmetrical distribution and/or activity of various ion-transport mechanisms. In the present study, we analysed the patterns of basal microfilaments (bMF) and microtubules (MT) in relation to electrochemical signals. Results The bMF- and MT-patterns in developmental stages 8 to 12 were visualised using labelled phalloidin and an antibody against acetylated α-tubulin as well as follicle-cell specific expression of GFP-actin and GFP-α-tubulin. Obviously, stage-specific changes of the pHi- and Vmem-gradients correlate with modifications of the bMF- and MT-organisation. In order to test whether cytoskeletal modifications depend directly on bioelectrical changes, we used inhibitors of ion-transport mechanisms that have previously been shown to modify pHi and Vmem as well as the respective gradients. We inhibited, in stage 10b, Na+/H+-exchangers and Na+-channels with amiloride, V-ATPases with bafilomycin, ATP-sensitive K+-channels with glibenclamide, voltage-dependent L-type Ca2+-channels with verapamil, Cl−-channels with 9-anthroic acid and Na+/K+/2Cl−-cotransporters with furosemide, respectively. The correlations between pHi, Vmem, bMF and MT observed in different follicle-cell types are in line with the correlations resulting from the inhibition experiments. While relative alkalisation and/or hyperpolarisation stabilised the parallel transversal alignment of bMF, acidification led to increasing disorder and to condensations of bMF. On the other hand, relative acidification as well as hyperpolarisation stabilised the longitudinal orientation of MT, whereas alkalisation led to loss of this arrangement and to partial disintegration of MT. Conclusions We conclude that the pHi- and Vmem-changes induced by inhibitors of ion-transport mechanisms simulate bioelectrical changes occurring naturally and leading to the cytoskeletal changes observed during differentiation of the follicle-cell epithelium. Therefore, gradual modifications of electrochemical signals can serve as physiological means to regulate cell and tissue architecture by modifying cytoskeletal patterns.