The sternocleidomastoid muscle variations: a mini literature review

The sternocleidomastoid muscles (SCM) are prominent paired muscles of the neck connecting proximally the manubrium sterni and the clavicle to the mastoid process and the occipital bone distally. Following their points of attachment sternomastoid, sternooccipital, cleidomastoid and cleidooccipital portions of this muscle have been described. Altogether 23 case reports from year 2000 till 2020 with 29 subjects related to the SCM supernumerary variations were searched and analyzed where parameters such as supernumerary proximal variation types (sternal vs. clavicular), insertional variation, unilaterality/ bilaterality of the variation, study type, reported gender of the subjects and the country of research were extracted. The research shows that 48.3% of the subjects had bilateral presentation of SCM variations. If present unilaterally, three quarters of the cases were on the left side. The most frequent variation is located at the clavicular side of the proximal SCM head whereas isolated sternal sided proximal head variation or an insertional variation alone are very rare. Interestingly, with 96.6%, most of cases in the literature were discovered in cadavers during anatomical dissections. Male gender represented with 82.8% higher prevalence than females. The higher male prevalence in the body donor system, predominantly in the Asian continent could play a decisive role in the outcome as more than half of the reported cases stemmed from India in this period. Importantly, the knowledge of different anatomical variations of the SCM is highly relevant for surgical, clinical or radiological approaches in the neck

Viscoelastic Behavior of Embroidered Scaffolds for ACL Tissue Engineering Made of PLA and P(LA-CL) After In Vitro Degradation

A rupture of the anterior cruciate ligament (ACL) is the most common knee ligament injury. Current applied reconstruction methods have limitations in terms of graft availability and mechanical properties. A new approach could be the use of a tissue engineering construct that temporarily reflects the mechanical properties of native ligament tissues and acts as a carrier structure for cell seeding. In this study, embroidered scaffolds composed of polylactic acid (PLA) and poly(lactic-co-"-caprolactone) (P(LA-CL)) threads were tested mechanically for their viscoelastic behavior under in vitro degradation. The relaxation behavior of both scaffold types (moco: mono-component scaffold made of PLA threads, bico: bi-component scaffold made of PLA and P(LA-CL) threads) was comparable to native lapine ACL. Most of the lapine ACL cells survived 32 days of cell culture and grew along the fibers. Cell vitality was comparable for moco and bico scaffolds. Lapine ACL cells were able to adhere to the polymer surfaces and spread along the threads throughout the scaffold. The mechanical behavior of degrading matrices with and without cells showed no significant differences. These results demonstrate the potential of embroidered scaffolds as an ACL tissue engineering approach. © 2019 by the authors. Licensee MDPI, Basel, Switzerland

an experimental study in the rat osteoarthritis model

Background Anti-inflammatory nanoparticular compounds could represent a strategy to diminish osteoarthritis (OA) progression. The present study was undertaken to prove the uptake of nanoparticular dendritic polyglycerol sulfates (dPGS) by rat-derived articular chondrocytes and to answer the question of whether dPGS could modulate knee joint cartilage degradation in a rat OA model and whether complications could arise. Methods dPGS uptake and cytotoxicity was assessed in cultured primary rat-derived articular chondrocytes. Subsequently, OA was induced in the right knee joints of 12 male Wistar rats by medial collateral ligament and meniscus transection. Unoperated left knees remained as controls. Six weeks post surgery six rats were either treated daily (14 days) with 30 mg/kg dPGS (s.c.) or a similar volume of physiological saline. Animals were analyzed clinically for gait alterations. Explanted knee joints were studied histologically using OA scores according to Mankin (1971), Glasson et al., (2010) and the synovitis score according to Krenn et al., (2006). Liver, spleen and kidneys were analyzed for degenerative changes due to dPGS accumulation. Results dPGS was taken up after 2 hours by the chondrocytes. Whereas no significant clinical signs of OA could be detected, at the histological level, all operated rat knee joints revealed features of OA in the medial compartment. The values produced by both OA score systems were lower in rats treated with dPGS compared with saline-treated animals. Synovitis score did not significantly differ between the groups. The analyzed organs revealed no degenerative changes. Conclusions dPGS presented overall cyto- and biocompatibility, no accumulation in metabolizing organs and chondroprotective properties in the osteoarthritic knee joint

Rare malformations associated with partial anomalous pulmonary venous return: a cadaveric case report

A unique partial anomalous pulmonary venous return in combination with other rare malformations such as annular pancreas and a persistent umbilical vein was discovered in a female Caucasian cadaver during an anatomical dissection at the Paracelsus Medical University in Nuremberg, Germany. The pulmonary anomaly comprised the aberrant left superior pulmonary vein connecting the superior lobe of the left lung with the left brachiocephalic vein resulting in a left to right shunt. An annular pancreas without any signs causing duodenal compression was additionally found. To complete the constellation of malformations, a persistent umbilical vein within the round ligament fissure of the liver was also observed, connecting to an inferior branch of the extrahepatic left ramus of the portal vein. This rare constellation of malformations has been illustrated and thoroughly discussed with the currently available literature to develop a hypothesis for the genetic and developmental background

Gas-Phase Fluorination on PLA Improves Cell Adhesion and Spreading

For the regeneration or creation of functional tissues, biodegradable biomaterials including polylactic acid (PLA) are widely preferred. Modifications of the material surface are quite common to improve cell-material interactions and thereby support the biological outcome. Typical approaches include a wet chemical treatment with mostly hazardous substances or a functionalization with plasma. In the present study, gas-phase fluorination was applied to functionalize the PLA surfaces in a simple and one-step process. The biological response including biocompatibility, cell adhesion, cell spreading, and proliferation was analyzed in cell culture experiments with fibroblasts L929 and correlated with changes in the surface properties. Surface characterization methods including surface energy and isoelectric point measurements, X-ray photoelectron spectroscopy, and atomic force microscopy were applied to identify the effects of fluorination on PLA. Gas-phase fluorination causes the formation of C-F bonds in the PLA backbone, which induce a shift to a more hydrophilic and polar surface. The slightly negatively charged surface dramatically improves cell adhesion and spreading of cells on the PLA even with low fluorine content. The results indicate that this improved biological response is protein-but not integrin-dependent. Gas-phase fluorination is therefore an efficient technique to improve cellular response to biomaterial surfaces without losing cytocompatibility. Copyright © 2020 American Chemical Society

Tubular composite scaffolds produced via Diffusion Induced Phase Separation (DIPS) as a shaping strategy for anterior cruciate ligaments reconstruction

Injuries of tendons and ligaments are common, especially among the young population. Anterior cruciate ligament (ACL) injuries do not heal due to its limited vascularization and hence, surgical intervention is usually required. The ideal scaffold for ligament tissue engineering (TE) should be biocompatible and possess mechanical and functional characteristics comparable to the native ACL. The Diffusion Induced Phase Separation (DIPS) technique allows the preparation of homogenous porous tubular scaffold with micro-pores using a rather simple procedure. Composites based on biodegradable polymers and bioglass have attracted much attention in tissue reconstruction and repair because of their biological and physicochemical advantages. In this work a new approach in ACL TE will be proposed focussing on the development of a suitable technique for in vitro seeding of lapine ACL fibroblasts into tubular-shaped instructive Poly-lactic-acid (PLLA) scaffolds, supplemented or not with bioglass (BG) 1393, produced via DIPS. Tubular composite scaffold (diameters: 1.2 and 2 mm, +/- BG) were obtained through a dip coating around a cylindrical support followed by a DIPS. An 8%wt PLLA/dioxane solution was prepared with 5%wt of BG-1393 as filler. Preliminary in vitro cell culture trials were carried out by seeding lapine ACL fibroblasts inside the scaffolds (2 cm as length) employing different seeding strategies in order to find the best way that allows to obtain a homogeneous fibroblast distribution inside the tubes. (1) First trials consisted in the inoculating of the cell suspension inside the tubes and maintaining them in dynamical culture. (2) The second one was done by suspending the cells in a fibrin gel polymerized within the tubes by using of thrombin. (3) The third approach was carried out by using cell spheroids (three-dimensional self-assembled cell agglomerates). Cell attachment, viability and morphology were examined by live-death and Hematoxylin/Eosin stainings after 1, 7, 14 d and vimentin immunolabelings (7 d). Scanning electron microscopical analysis revealed that the internal surface of the tubes was homogeneously structured with micropores sized around 5 µm and a mean thickness of the wall of 60 µm. The results showed cell adhesion to the wall of the tubes with all seeding techniques applied even though with fibrin gel it was more homogenous. Furthermore, colonized areas expanded with culture time and the majority of cell survived irrespectively of seeding techniques. (1) In inoculation phase, many cells left the scaffold and attached on the plate. Even after the dynamic culture (rotating device) most cells covered only half the tube inner surface. (2) In the second trial, a fibrin gel was used to achieve a homogenous cell distribution during seeding. In the early stage (48 h) cells remained captured inside the fibrin, but after 7 d they become elongated and migrated from the fibrin to the inner tube surface forming a compact cell layer. So, the fibrin appears helpful to achieve an immediate high cell seeding efficiency and an almost homogeneous cell distribution inside the tubes. (3) Although using the spheroid technique the scaffold internal surface was not homogeneously colonized with cells, after 7 d cell migration to the inner scaffold surface from the attaching spheroids could be observed. In longitudinal sections cells were elongated like typical ligament fibroblasts parallel to the longitudinal tube axis. Therefore, it can be affirmed that employment of tubular scaffolds produced by DIPS could be a promising approach of ligament TE. In the future, it would be interesting to evaluate the effectiveness of seeding by combining the spheroids and the fibrin gel

Dendritic polyglycerol anions for the selective targeting of native and inflamed articular cartilage

The destruction of articular cartilage is a critical feature in joint diseases. An approach to selectively target the damaged tissue is promising for the development of diagnostic and therapeutic agents. We herein present the interaction of dendritic polyglycerol (dPG) anions with native and inflamed cartilage. Confocal laser scanning microscopy revealed the inert character of dPG and low functionalized dPG bisphosphonate (dPGBP7%) toward cartilage in vitro. An enhanced binding was observed for highly functionalized dPG bisphosphonate, sulfate, and phosphate, which additionally showed a higher affinity to IL-1β treated tissue. The mixed anion containing sulfate and bisphosphonate groups exhibited an exceptionally high affinity to cartilage and strongly bound to collagen type II, as shown by a normalized fluorescence-based binding assay. All polyglycerol anions, except dPGBP7%, were taken up by chondrocytes within 24 h and no cytotoxicity was found up to 10−5 M. In a rheumatoid arthritis model, dPGBP7% accumulated in mineralized compartments of inflamed joints and showed an increasing affinity to cartilage with higher clinical scores, as evident from histological examinations. For dPGS no interaction with bone but a strong binding to cartilage, independent of the score, was demonstrated. These results make dPG anions promising candidates for the selective targeting of cartilage tissue

Biological characterization of Poly-L-lactic acid (PLLA)/Hydroxyapatite (HA)/Bioglass (BG) composite scaffolds made by Thermally Induced Phase Separation (TIPS) hosting human Mesenchymal Stem Cells

In the last few years, Tissue Engineering has focused on the favourable effects that composite scaffolds have on cell adhesion, growth and differentiation. In fact, composite scaffolds, usually composed of a synthetic polymer supplemented with naturally occurring components, display superior mechanical properties and bioconductivity than scaffolds consisting of a single component. Hydroxyapatite (HA) is the major inorganic component of bones. Bioglass (BG) is known to exert stimulatory effects on cells by ion release and hence, could be also advantageous for Bone Tissue Engineering. Poly-L-lactic acid (PLLA) is a versatile synthetic polymer combinable with HA and BG. The aim of this work was to assess the effectiveness of PLLA/HA and PLLA/HA/BG 1393 composite scaffolds as suitable artificial Extracellular Matrix (ECM) for human Mesenchymal Stromal Cells (h-MSCs). In order to check if composite scaffolds are actually superior, a comparison was made between the scaffolds above mentioned and PLLA and PLLA/BG scaffolds. All four types of scaffolds (PLLA, PLLA/HA, PLLA/BG and PLLA/HA/BG) were manufactured in Palermo, at the University of Palermo, using the Thermally Induced Phase Separation (TIPS) technique, for which a PLLA/1,4-dioxane/water ternary solution was chosen. In composite scaffolds, HA and BG 1393 were added in the solution as powder phase. The temperature selected for promoting the phase separation was 30 °C and the residence time in the thermostatic bath was set to 80 minutes. The samples were then placed in a cooling bath at -20 °C for 15 minutes, in order to freeze the porous structure thus formed. With these process conditions, scaffolds with a porosity higher than 90% and a mean pore size of 100 μm were obtained. After subsequent washing and drying steps, the as-obtained cylindrical structures were cut in disk-shaped specimens with a diameter of 6 mm and a thickness of 1.5 mm. Before the seeding stage, scaffolds were sterilized in 70% ethanol solution, stored in Phosphate Buffered Saline (PBS) and finally soaked in h-MSCs culture medium. The seeding of h-MSCs occurred in a 96-well plate and monitoring analyses were carried out at time points of 48 hours and 8 days. Before used for seeding experiments, undifferentiated MSCs were characterized for a set of markers (CD34, CD44, CD45, CD90, CD105, Vimentin) to show their typical expression pattern before seeding. Multilineage differentiation potential was proven by adipogenic, osteogenic and chondrogenic differentiation. Life/dead assays, Haematoxylin/Eosin, Alcian blue and Alizarin red stainings were employed to verify cells viability, ECM synthesis, adhesion to the polymeric structure and migration into the scaffold. Cell proliferation was calculated from DNA content using CyQuant assay. h-MSCs expressed the typical markers, they were able to spread evenly on both upper and lower surfaces of all types of scaffold. The majority of the adhering cells survived on the scaffolds over the whole observation period. Scaffolds supplemented with HA revealed a higher seeded area compared with PLLA and BG alone. Furthermore, h-MSCs penetrated in mean 260 µm into the porous polymeric structure of all scaffolds. The next step will involve long time experiments with h-MSCs under osteogenic and non-osteogenic conditions in the same types of scaffolds. Successful osteogenic differentiation will be tested by monitoring osteogenic marker expression, e.g. type X collagen