Communication between Mast Cells and Group 2 Innate Lymphoid Cells in the Skin.

The skin is a dynamic organ with a complex immune network critical for maintaining balance and defending against various pathogens. Different types of cells in the skin, such as mast cells (MCs) and group 2 innate lymphoid cells (ILC2s), contribute to immune regulation and play essential roles in the early immune response to various triggers, including allergens. It is beneficial to dissect cell-to-cell interactions in the skin to elucidate the mechanisms underlying skin immunity. The current manuscript concentrates explicitly on the communication pathways between MCs and ILC2s in the skin, highlighting their ability to regulate immune responses, inflammation, and tissue repair. Furthermore, it discusses how the interactions between MCs and ILC2s play a crucial role in various skin conditions, such as autoimmune diseases, dermatological disorders, and allergic reactions. Understanding the complex interactions between MCs and ILC2s in different skin conditions is crucial to developing targeted treatments for related disorders. The discovery of shared pathways could pave the way for novel therapeutic interventions to restore immunological balance in diseased skin tissues.

Melt electrowriting of PLA, PCL, and composite PLA/PCL scaffolds for tissue engineering application.

Fabrication of well-ordered and bio-mimetic scaffolds is one of the most important research lines in tissue engineering. Different techniques have been utilized to achieve this goal, however, each method has its own disadvantages. Recently, melt electrowriting (MEW) as a technique for fabrication of well-organized scaffolds has attracted the researchers' attention due to simultaneous use of principles of additive manufacturing and electrohydrodynamic phenomena. In previous research studies, polycaprolactone (PCL) has been mostly used in MEW process. PCL is a biocompatible polymer with characteristics that make it easy to fabricate well-arranged structures using MEW device. However, the mechanical properties of PCL are not favorable for applications like bone tissue engineering. Furthermore, it is of vital importance to demonstrate the capability of MEW technique for processing a broad range of polymers. To address aforementioned problems, in this study, three ten-layered box-structured well-ordered scaffolds, including neat PLA, neat PCL, and PLA/PCL composite are fabricated using an MEW device. Printing of the composite PLA/PCL scaffold using the MEW device is conducted in this study for the first time. The MEW device used in this study is a commercial fused deposition modeling (FDM) 3D printer which with some changes in its setup and configuration becomes prepared for being used as an MEW device. Since in most of previous studies, a setup has been designed and built for MEW process, the use of the FDM device can be considered as one of the novelties of this research. The printing parameters are adjusted in a way that scaffolds with nearly equal pore sizes in the range of 140 µm to 150 µm are fabricated. However, PCL fibers are mostly narrower (diameters in the range of 5 µm to 15 µm) than PLA fibers with diameters between 15 and 25 µm. Unlike the MEW process of PCL, accurate positioning of PLA fibers is difficult which can be due to higher viscosity of PLA melt compared to PCL melt. The printed composite PLA/PCL scaffold possesses a well-ordered box structure with improved mechanical properties and cell-scaffold interactions compared to both neat PLA and PCL scaffolds. Besides, the composite scaffold exhibits a higher swelling ratio than the neat PCL scaffold which can be related to the presence of less hydrophobic PLA fibers. This scaffold demonstrates an anisotropic behavior during uniaxial tensile test in which its Young's modulus, ultimate tensile stress, and strain to failure all depend on the direction of the applied tensile force. This anisotropy makes the composite PLA/PCL scaffold an exciting candidate for applications in heart tissue engineering. The results of in-vitro cell viability test using L929 mouse murine fibroblast and human umbilical vein endothelial (HUVEC) cells demonstrate that all of the printed scaffolds are biocompatible. In particular, the composite scaffold presents the highest cell viability value among the fabricated scaffolds. All in all, the composite PLA/PCL scaffold shows that it can be a promising substitution for neat PCL scaffold used in previous MEW studies.

Lunate intraosseous ganglion cysts and chronic wrist pain- reporting six cases.

BACKGROUND: Intraosseous ganglion (IOG) cysts rarely have been reported in the carpal bones and lunate is the most common area of involvement. They can present as chronic wrist pain accompanied by a radiolucent lytic lesion in the lunate bone. We provided a retrospective review of six cases of intraosseous ganglion cysts within the lunate bones that all of the patients presented with chronic wrist pain. METHODS: We retrospectively reviewed the medical records, pathologic reports and imaging files of the six patients who were referred and treated due to chronic wrist pain with final diagnosis of the lunate intraosseous ganglion. All cases were treated by curettage and autologous cancellous bone grafting.  RESULTS: There were six patients with final diagnosis of the lunate IOG who received surgical treatment. Four out of six patients were female and the remaining was male. Mean age of the patients was 33 years (22 - 56). Right wrist was involved in four patients. Pain was the chief complain in all patients. Mean time of suffering from the wrist pain till referring to hand clinic for definite treatment was nine months (3 - 24). Mean duration of follow up was 30.6 months (6 - 48). The wrists became pain free after surgical treatment and no graft absorption or recurrences were seen in the control radiographs obtained throughout the follow-up period. CONCLUSION: Diagnosis of intraosseous ganglion was based on the imaging features and clinical presentation. Although most cases of the lunate bone IOGs are symptom free and found incidentally after wrist imaging performed for other reasons, these lytic lesions should be included in differential diagnosis list of chronic wrist pain especially in the presence of increased uptake in bone scan located on the lunate area.