Background Exosome administration is a novel medical approach that promises excellent immunomodulatory properties without the conventional side effects of current antitumor necrosis factor drugs and stem cells. This study aimed to assess the safety and efficacy of using mesenchymal stem cell (MSC) exosomes to treat refractory fistulas in patients with inflammatory bowel disease. Methods MSCs were derived from the umbilical cords and their exosomes were isolated. Five patients with refractory perianal Crohn’s disease fistulas with a median age of 35 years (range 31–47 years) were enrolled in the study. Exosome injections were administered in the operating room to patients with refractory fistula (fistulas that are irresponsive to anti-tumor necrosis factor-α administration within 6 months). Six months later, a physical examination, face-to-face interviews, and magnetic resonance imaging were employed to evaluate the therapy responses of patients. Results The outcomes within 6 months after initiation of therapy showed that four patients had responded to therapy. Three patients who received exosome injections exhibited complete healing, while one reported no improvement and active discharge from the fistula site. In addition, five patients (100%) reported neither systemic nor local adverse effects. Conclusions Injection of exosomes extracted from MSCs demonstrates safety and a satisfactory therapeutic effect, as evidenced in this and other studies, and may play a significant role in the future treatment of gastrointestinal fistulas.

Due to their high entrapment efficiency, anodized titanium nanotubes (TiO2-NTs) are considered effective reservoirs for loading/releasing strong antibiotics whose systemic administration is associated with diverse and severe side-effects. In this study, TiO2-NTs were synthesized by anodic oxidation of titanium foils, and the effects of electrolyte percentage and viscosity on their dimensions were evaluated. It was found that as the water content increased from 15 to 30%, the wall thickness, length, and inner diameter of the NTs increase from 5.9 to 15.8 nm, 1.56 to 3.21 µm, and 59 to 84 nm, respectively. Ciprofloxacin, a highly potent antibiotic, was loaded into TiO2-NTs with a high encapsulation efficiency of 93%, followed by coating with different chitosan layers to achieve a sustained release profile. The prepared formulations were characterized by various techniques, such as scanning electron microscopy, differential scanning calorimetry, and contact measurement. In vitro release studies showed that the higher the chitosan layer count, the more sustained the release. Evaluation of antimicrobial activity of the formulation against two endodontic species from Peptostreptococcus and Fusobacterium revealed minimum inhibitory concentrations (MICs) of 1 µg/mL for the former and the latter. To summarize, this study demonstrated that TiO2-NTs are promising reservoirs for drug loading, and that the chitosan coating provides not only a sustained release profile, but also a synergistic antibacterial effect.

Background and Aim:A perianal fistula is an abnormal tract that connects anal canal to skin. Current medical and surgical interventions have a high failure rate particularly in complex and refractory cases. MSC-derived exosomes have demonstrated immunomodulatory effects without the conventional complications; hence, in this study, we evaluated the safety of their application for complex perianal fistula. Methods: Placenta-derived MSCs were cultured, and exosomes were isolated using ultracentrifugation. Exosome injections were administered in the operating room to 11 patients with complex perianal fistula (presence of fistulas for at least 1 year alongside medical and surgical treatment). The patients were followed for 6 months, and the patients were evaluated using physical examination, face-to-face interviews, and magnetic resonance imaging (MRI). Results: Among 11 patients only one did not show any improvement upon physical examination. Five patients showed complete tract resolve. While the discharge was stopped in eight patients, two patients showed only reduction. None of the patients showed any acute or latent allergic reaction or injection related complications. Conclusion: Administration of exosomes isolated from MSCs demonstrates safety and a satisfactory therapeutic effect in treatment complex perianal fistulae; therefore, it can be a candidate for future studies and might play a significant role in treatment.Ethical approval: This study was submitted to and ethically approved by the Iranian clinical registry system and committee under the reference number "IRCT20200413047063N3." This study was also approved by the Research Deputy and the Ethics Committee of the Tehran University of Medical Sciences (Reference number: IR.TUMS.IKHC. REC.1400.184). This study was also approved by the US Clinical Trial Registry (reference number: NCT05402748) and was carried out per the ethical standards outlined in the 1964 Declaration of Helsinki and all subsequent revisions. All participants signed a written informed consent form. Informed consent: All patients signed informed consent forms. Financial support: This study was self-funded by its authors and received no funding from any government/non-governmental organization. 1 Haleh Pak and Alireza Hadizadeh contributed equally to this study.

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Background and Aims Coronary artery disease is high‐risk comorbidity of COVID‐19 infection. Nonelective coronary artery revascularization in COVID‐19 patients carries substantial risk. Therefore, it is essential to understand the risk factors and outcomes fully. This study aims to evaluate the prognosis of coronary artery bypass grafting (CABG) surgery in patients with COVID‐19. Methods This retrospective cohort study assesses 171 patients who underwent urgent and emergent CABG in Tehran Heart Center from March 2020 to September 2021. The patients were allocated to cases and controls based on COVID‐19 infection status. Demographic and clinical features, alongside the complications and outcomes, were compared between the two groups. Results According to diagnostic criteria, 62 patients were diagnosed with COVID‐19 (Case) and 109 patients had no COVID diagnosis (Control). Regarding the demographics and risk factors, hypertension was more prevalent among patients with COVID‐19 (64.5% compared to 43.1% p = 0.007). Length of hospital stay, ventilation time, and intensive care unit (ICU) stay time were significantly higher in patients infected with COVID‐19. Postoperative complications, including stroke, atrial fibrillation, pleural effusion, blood transfusion, and Inotrope use, were significantly higher in the case group. Mortality rates were also higher in COVID‐19 patients with an odds ratio of 1.53; however, this difference is not statistically significant ( p : 0.44, 95% CI = 0.50–4.01). Conclusion COVID‐19 is associated with a significantly higher hospital stay, ventilation time, and ICU stay. Mortality rates are also higher, albeit insignificantly. Various postoperative complications are also higher with COVID‐19.