Reinforcing decellularized small intestine submucosa with cellulose acetate nanofibrous and silver nanoparticles as a scaffold for wound healing applications.

BACKGROUND: The formation of chronic wounds accounts for considerable costs in health care systems. Despite the several benefits of decellularized small intestinal submucosa (SIS) as an appropriate scaffold for different tissue regeneration, it has shortcomings such as lack of antibacterial features and inappropriate mechanical properties for skin tissue regeneration. We aimed to examine the efficacy and safety of decellularized SIS scaffold enhanced with cellulose acetate (CA) and silver (Ag) nanoparticles (NPs) for healing full-thickness wounds. METHODS AND RESULTS: The scaffolds were prepared by decellularizing bovine SIS and electrospinning CA/Ag nanoparticles and characterized using a transmission electron microscope (TEM), scanning electron microscope (SEM), tensile testing, and X-ray diffraction. In vivo evaluations were performed using full-thickness excisions covered with sterile gauze as the control group, SIS, SIS/CA, and SIS/CA/Ag scaffolds on the dorsum of twenty male Wistar rats divided into four groups randomly with 21-days follow-up. All in vivo specimens underwent Masson's trichrome (MT) staining for evaluation of collagen deposition, transforming growth factor-ß (TGF-ß) immunohistochemistry (IHC), and Haematoxylin Eosin (H&E) staining. The IHC and MT data were analyzed with the ImageJ tool by measuring the stained area. The TEM results revealed that Ag nanoparticles are successfully incorporated into CA nanofibers. Assessment of scaffolds hydrophilicity demonstrated that the contact angle of SIS/CA/Ag scaffold was the lowest. The in vivo results indicated that the SIS/CA/Ag scaffold had the most significant wound closure. H&E staining of the in vivo specimens showed the formation of epidermal layers in the SIS/CA/Ag group on day 21. The percentage of the stained area of MT and TGF-ß IHC staining's was highest in the SIS/CA/Ag group. CONCLUSION: The decellularized SIS/CA/Ag scaffolds provided the most significant wound closure compared to other groups and caused the formation of epidermal layers and skin appendages. Additionally, the collagen deposition and expression of TGF-ß increased significantly in SIS/CA/Ag group.

3D-printing of alginate/gelatin scaffold loading tannic acid@ZIF-8 for wound healing: In vitro and in vivo studies.

In the present study, ZIF-8 metal-organic framework (MOF) modified with Tannic acid (TA@ZIF-8) was synthesized and impregnated in alginate-gelatin (Alg-Gel) hydrogel. The Alg-Gel scaffolds containing 0, 5, and 10 % of TA@ZIF-8 were fabricated through the 3D printing method specifically denoted as Alg-Gel 0 %, Alg-Gel 5 %, and Alg-Gel 10 %. XRD, FTIR, FESEM, and EDX physically and chemically characterized the synthesized ZIF-8 and TA@ZIF-8 MOFs. Besides, Alg-Gel containing TA@ZIF-8 prepared scaffolds and their biological activity were also evaluated. SEM images verified the nano-size formation of MOFs. Improved swelling and decreased degradation rates after adding TA@ZIF-8 were also reported. Increased compression strength from 0.628 to 1.63 MPa in Alg-Gel 0 % and Alg-Gel 10 %, respectively, and a 2.19 increase in elastic modulus in Alg-Gel 10 % scaffolds were exhibited. Biological activity of scaffolds, including Live-dead and Cell adhesion, antibacterial, in-vivo, and immunohistochemistry assays, demonstrated desirable fibroblast cell proliferation and adhesion, increased bacterial growth inhibition zone, accelerated wound closure and improved expression of anti-inflammatory cytokines in Alg-Gel 10 % scaffolds. The findings of this study confirm that Alg-Gel 10 % scaffolds promote full-thickness wound healing and could be considered a potential candidate for full-thickness wound treatment purposes.

Safety and efficacy of injection of human placenta mesenchymal stem cells derived exosomes for treatment of complex perianal fistula in non-Crohn's cases: Clinical trial phase I.

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.

Design and fabrication of modified bi-layer poly vinyl alcohol adhesive sealant film for preventing gastrointestinal leakage.

Anastomosis leakage is a common complication in gastrointestinal surgery associated with high mortality, morbidity, and cost to health care providers. According to the significant burdens of AL, several methods have been introduced to overcome this problem. Despite the crucial complications of the AL, current approaches, including glue-based adhesives and bio-based sealants, have certain disadvantages and newly gained attractions for solving this challenge. This study focused on fabricating a sealant structure based on poly (vinyl alcohol) film patterned with gelatin particles and evaluating for prevention of AL. Here, we used a 3D printed model for dry spraying gelatin particles in a random and oriented pattern on PVA films. The mechanical and adhesion properties of both types of films were assessed further, and the efficacy of the novel sealant was evaluated in vivo. The results revealed that the film with an oriented pattern provided better adhesive and mechanical properties, expression of anti-inflammatory cytokines, and collagen deposition. In conclusion, our novel sealant enhanced mechanical features and the healing process of gastrointestinal surgical anastomosis and can be considered a novel method for the prevention of AL.

Evaluating the safety and efficacy of mesenchymal stem cell-derived exosomes for treatment of refractory perianal fistula in IBD patients: clinical trial phase I.

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.

Surgical management of retrorectal tumors: a single-center 12 years' experience.

Purpose: Retrorectal tumors (RTs) are rare tumors that arise in the space between the mesorectum and the pelvic wall and often originate in embryonic tissues. The primary treatment for these tumors is complete excision surgery, and choosing the best surgical approach is very important. Methods: In this study, we retrospectively collected the data of 15 patients with RTs who underwent surgery in the surgical ward of Imam Khomeini Hospital in Tehran for 12 years to share our experiences of patients' treatment and compare different surgical approaches. Results: A total of 5 tumors were malignant, 10 were benign, and most of the tumors were congenital. Malignant tumors were seen in older patients. Three surgical procedures were performed on patients. Three patients underwent abdominal approach surgery, and 8 patients underwent posterior surgery. A combined surgical approach was performed on 4 patients. Two patients underwent laparoscopic surgery. The abdominal approach had the least long-term complication, and the combined approach had the most complications; laparoscopic surgery reduced the length of hospital stay and complications after surgery. Conclusion: A multidisciplinary team collaboration using magnetic resonance imaging details is necessary to determine a surgical treatment approach. It could reduce the need for a preoperative biopsy. However, every approach has its advantages and disadvantages. In the main, they have no superiority over each other, and individualized treatment is the key.