Preparation and Characterization of Graphene-Based 3D Biohybrid Hydrogel Bioink for Peripheral Neuroengineering.

Peripheral neuropathies can occur as a result of axonal damage, and occasionally due to demyelinating diseases. Peripheral nerve damage is a global problem that occurs in 1.5%-5% of emergency patients and may lead to significant job losses. Today, tissue engineering-based approaches, consisting of scaffolds, appropriate cell lines, and biosignals, have become more applicable with the development of three-dimensional (3D) bioprinting technologies. The combination of various hydrogel biomaterials with stem cells, exosomes, or bio-signaling molecules is frequently studied to overcome the existing problems in peripheral nerve regeneration. Accordingly, the production of injectable systems, such as hydrogels, or implantable conduit structures formed by various bioprinting methods has gained importance in peripheral neuro-engineering. Under normal conditions, stem cells are the regenerative cells of the body, and their number and functions do not decrease with time to protect their populations; these are not specialized cells but can differentiate upon appropriate stimulation in response to injury. The stem cell system is under the influence of its microenvironment, called the stem cell niche. In peripheral nerve injuries, especially in neurotmesis, this microenvironment cannot be fully rescued even after surgically binding severed nerve endings together. The composite biomaterials and combined cellular therapies approach increases the functionality and applicability of materials in terms of various properties such as biodegradability, biocompatibility, and processability. Accordingly, this study aims to demonstrate the preparation and use of graphene-based biohybrid hydrogel patterning and to examine the differentiation efficiency of stem cells into nerve cells, which can be an effective solution in nerve regeneration.

Formulating and Characterizing an Exosome-based Dopamine Carrier System.

Exosomes between 40 and 200 nm in size constitute the smallest subgroup of extracellular vesicles. These bioactive vesicles secreted by cells play an active role in intercellular cargo and communication. Exosomes are mostly found in body fluids such as plasma, cerebrospinal fluid, urine, saliva, amniotic fluid, colostrum, breast milk, joint fluid, semen, and pleural acid. Considering the size of exosomes, it is thought that they may play an important role in central nervous system diseases because they can pass through the blood-brain barrier (BBB). Hence, this study aimed to develop an exosome-based nanocarrier system by encapsulating dopamine into exosomes isolated from Wharton's jelly mesenchymal stem cells (WJ-MSCs). Exosomes that passed the characterization process were incubated with dopamine. The dopamine-loaded exosomes were recharacterized at the end of incubation. Dopamine-loaded exosomes were investigated in drug release and cytotoxicity assays. The results showed that dopamine could be successfully encapsulated within the exosomes and that the dopamine-loaded exosomes did not affect fibroblast viability.

Polymeric Approach to Adjuvant System in Antibody Production against Leishmaniasis Based on Hybridoma Technology.

Background: Leishmaniasis is a zoonotic disease, which is one of the serious public health problems in the world. Nowadays, antibody production using hybridoma technology may be a correct approach in terms of sensitivity in the diagnosis of diseases such as leishmaniasis. The aim of this study was investigation of the effectiveness of different adjuvants on polyclonal antibody production against L. tropica based on hybridoma technique. Methods: Accordingly, Freund's adjuvant (1956, M. tuberculosis), as a classic adjuvant in studies, was used comparatively with the non-toxic polymeric based Polyoxidonium adjuvant. All animal immunization procedures were conducted at Bezm-i Alem University Experimental Animal Research Center. The adjuvant response was tested both in the serum sample and in the antibodies produced by the hybridomas. The antibody titers were determined with ELISA. Results: Freund's and Polyoxidonium (PO) group blood titer's increased approximately 5.5 fold compared to control after the 6th and 8th immunization. Hybridomas produced from mice immunized with PO adjuvant induced only antigen-specific antibody response and did not develop an immune response against the adjuvant. Conclusion: Adjuvant selection is very important in terms of the specificity of antibody responses of cells produced in hybridoma technology. Therefore, PO is recommended as a new adjuvant system in this study.

[Postoperative analgesic effect of acupuncture in laparoscopic cholecystectomy surgery]. / Laparoskopik kolesistektomi operasyonlarinda akupunktur uygulamasinin ameliyat sonrasi analjeziye etkisi.

OBJECTIVES: In surgery clinics, postoperative pain is a common occurrence and care is needed in its treatment. One form of treatment is various acupuncture techniques. This study investigated the effect of acupuncture on postoperative analgesia in patients undergoing laparoscopic cholecystectomy. METHODS: A total of 59 patients undergoing laparoscopic cholecystectomy were included in the study; 31 comprised the acupuncture group (Group A), and 29 constituted the control group (group C). All patients underwent standard anesthesia procedures. Patient-controlled analgesia with tramadol was administered postoperatively. Patients' postoperative pain scores, results of the satisfaction questionnaire and amounts of tramadol used were recorded. Postoperative 0, 1st, 2nd, 6th, 12th and 18th hour controls were performed. RESULTS: A comparison of the groups showed Group A pain scores to be significantly lower statistically than those of Group C at all postoperative controls. There was no statistically significant difference for postoperative analgesic consumption and satisfaction level between the groups. CONCLUSION: Despite detection of a reduction in postoperative pain scores, the application of acupuncture did not cause any change in the consumption of tramadol.

A comparison of continuous femoral nerve block and periarticular local infiltration analgesia in the management of early period pain developing after total knee arthroplasty.

OBJECTIVE: This study aimed to compare the effects of 24-h continuous femoral nerve block (CFNB) and periarticular infiltration analgesia (PIA) on postoperative pain and functional results in the first 6 weeks after total knee arthroplasty (TKA). METHODS: Sixty patients who underwent unilateral TKA were included in this study. The patients were divided into two groups: Group A received CFNB and Group B received PIA. Each patient received 0.25% levobupivacaine and 1:100,000 epinephrine as infiltration to the posterior capsule. A patient-controlled analgesia (PCA) device was used for all patients, and 24-h tramadol usage by patients was recorded. We measured maximum range of motion (ROM), pain using a visual analog scale (VAS), 2-min walk test (2MWT), and the scores of Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Knee Society Score (KSS). RESULTS: Compared with Group B, Group A had lower postoperative opioid usage (p<0.05), less pain at rest (p<0.05), less pain with passive motion (p<0.05), less pain with movement and after active movement (p<0.05), and superior passive and active ROM (p<0.05). Group A also had better 2MWT results at 24 and 48 h after surgery (p<0.05), and superior WOMAC and KSS results at 6 weeks after surgery. CONCLUSION: As long as it is applied with infiltration analgesia to the posterior capsule, CFNB is an effective and safe analgesia method resulting in better postoperative patient comfort and greater ROM. Furthermore, it produces better results in the early postoperative period with a favorable side effect profile.

The Importance of FDG-PET/CT in Cogan's Syndrome.

The present study gives a detailed report of a patient with atypical Cogan's syndrome with uveitis and sensorineural hearing loss. Cogan's syndrome is characterized by nonsyphilitic interstitial keratitis and audiovestibular dysfunction. This syndrome can be divided into two groups, typical and atypical, based on the presence of interstitial keratitis. It may sometimes be associated with systemic vasculitis. Fluoro-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) scanning was used to investigate the presence of vasculitis. With FDG-PET/CT scanning, there is no pathological involvement in the walls of the arteries; thus the patient is protected from aggressive and long term immunosuppressive treatment's side effects. Hence, we can conclude that FDG-PET/CT may play an important role in excluding the presence of vasculitis.