Hydrogel nanocomposite based on alginate/zeolite for burn wound healing: In vitro and in vivo study.

Objectives: The main objective of the current assay was to evaluate the antibacterial and regenerative effects of hydrogel nanocomposite containing pure natural zeolite (clinoptilolite) integrated with alginate (Alg) as wound healing/dressing biomaterials. Materials and Methods: The zeolites were size excluded, characterized by SEM, DLS, XRD, FTIR, and XRF, and then integrated into Alg hydrogel followed by calcium chloride crosslinking. The Alg and alginate zeolite (Alg/Zeo) hydrogel was characterized by swelling and weight loss tests, also the antibacterial, hemocompatibility, and cell viability tests were performed. In animal studies, the burn wound was induced on the back of rats and treated with the following groups: control, Alg hydrogel, and Alg/Zeo hydrogel. Results: The results showed that the hydrodynamic diameter of zeolites was 367 ± 0.2 nm. Zeolites did not show any significant antibacterial effect, however, the hydrogel nanocomposite containing zeolite had proper swelling as well as hemocompatibility and no cytotoxicity was observed. Following the creation of a third-degree burn wound on the back of rats, the results indicated that the Alg hydrogel and Alg/Zeo nanocomposite accelerated the wound healing process compared with the control group. Re-epithelialization, granulation tissue thickness, collagenization, inflammatory cell recruitment, and angiogenesis level were not significantly different between Alg and Alg/Zeo nanocomposite. Conclusion: These findings revealed that although the incorporation of zeolites did not induce a significant beneficial effect in comparison with Alg hydrogel, using zeolite capacity in hydrogel for loading the antibiotics or other effective compounds can be considered a promising wound dressing.

Kermanian propolis induces apoptosis through upregulation of Bax/Bcl-2 ratio in acute myeloblastic leukemia cell line (NB4).

Objective: Propolis is a viscous resinous honeybee-produced substance with numerous medicinal functions; its composition and texture varies according to the geographic location. It is considered to be a promising natural source for the management and prevention of various pathological conditions. Although several studies have exhibited the anti-cancer activity of different types of propolis, the tumor-suppressing potential of Kermanian propolis against leukemia cell lines has remained poorly understood. Therefore, the current experiment was aimed to reveal the anti-tumor activity of this bioactive compound both as monotherapy and combined therapy with cytarabine against an acute myeloid leukemia (AML) cell line, NB4. Materials and Methods: Following the treatment of NB4 cells with either Kermanian propolis (5, 10, 20, 40, 80, 160, and 320 µg/mL), cytarabine (0.1, 0.25, 0.5, 0.75, 1, and 2 mM), or their combination (40 and 80 µg/mL of Kermanian propolis along with 0.1, 0.25, and 0.5 mM of cytarabine), colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was employed to measure the viability (%) of the cells. Next, to examine the apoptotic rate and the pattern of corresponding gene expression (Bcl-2, Bax, p53, and p21), Annexin-V/PI staining by flow cytometry and quantitative Real-Time polymerase chain reaction assays were performed, respectively. Results: We perceived significant apoptosis induction in a dose-dependent manner following the treatment with Kermanian propolis, cytarabine, and also their combination in the NB4 cell line. In addition, the combined treatment was associated with lower expression of the anti-apoptotic gene (Bcl-2) and higher expression of the pro-apoptotic genes (p53, Bax, and p21) in comparison to mono treatments. Conclusion: The synergistic anti-tumor activity induced by the combination of Kermanian propolis and cytarabine presents a novel and encouraging option for AML treatment.

Ubiquitous convalescent plasma: An artificial universal plasma for COVID-19 patients.

OBJECTIVES AND BACKGROUND: In December 2019, the first case of COVID-19 was reported in Wuhan, China. Its causative virus, is a novel strain of RNA viruses with high mortality rate. There is no definitive treatment, but among available approaches the use of recovered patients' plasma containing specific antibodies can enhance the immune response against coronavirus. However, the dearth of eligible donors and also ABO incompatibility in plasma transfusion, have limited this therapeutic method. Therefore, it is highly desirable to introduce a simple procedure that allows efficient reduction or even removal of natural ABO antibodies. Accordingly, we aimed to evaluate a RBC-mediated adsorption technique that reduces the titer of the mentioned antibodies in plasma. METHODS/MATERIALS: This experimental study was conducted in Kerman University of Medical Sciences, Kerman, Iran. The pre- and post-incubation antibody titers of 168 plasma samples were determined. For incubation, each plasma sample was exposed (60 min) to different percentages of RBCs at room temperature or 4 °C. RESULTS: The results evidenced that both the concentration of RBCs and temperature had significant decreasing effects on antibody titer (P < 0.001) and all concentrations significantly reduced titer. Compared to RT, 4 °C further reduced the antibody titer. Overall, the best incubation condition for reducing antibody titer in all blood groups was 4 °C and 2% RBCs concentration. CONCLUSION: The presented adsorption procedure is able to produce universal plasma (we call it Ubiquitous Convalescent Plasma) with a non-immunogenic level of ABO mismatch antibodies which can be used for COVID-19 patients with any type of blood group with desirable simplicity, feasibility, and efficacy.

A fibrinous and allogeneic fibroblast-enriched membrane as a biocompatible material can improve diabetic wound healing.

The application of conventional approaches to diabetic wound regeneration has some limitations. Thus, skin substitutes could be a new therapeutic possibility. In this regard, fibrin scaffolds are promising materials due to their desirable characteristics. Since defective fibroblasts caused by diabetes can disrupt regeneration, it seems that the use of living cells can improve the healing process. Thus, based on this fact, a cellular fibrin membrane was used to evaluate the diabetic wound healing in rats. The fibrin membrane was fabricated using fresh frozen plasma on which isolated fibroblasts were cultured. The wound model was created on 36 diabetic rats that were randomly divided into three groups: control, membrane, and cellular fibrin membrane (CM). Wound photogramography and immuno-histopathological staining were performed during consecutive days after treatment. Macroscopic evaluation of the wounds indicated a noteworthy enhancement of wound closure in the CM group. In the CM group, the re-epithelialization rate on day 7, 10 (p < 0.001), and 14 (p < 0.05), the fibroblast percentage on day 3 (p < 0.01) and 7 (p < 0.05) and the collagenization in all days were significantly higher than those of other groups (p < 0.001). The fibroblast number in the CM group on day 10 was significantly (p < 0.01) lower than that in the other groups. Contrary to the neutrophil and angiogenesis percentages that had no significant difference among the groups at different points of time (p > 0.05), the macrophage percentage on day 7 (P < 0.01), 10, and 14 (p < 0.05) was significantly lower in the CM group as compared to that in other groups. Overall, it seems that the use of a fibroblast-loaded fibrin membrane is an attractive strategy to promote diabetic wound healing.

Application and Assessment of Allogeneic Fibroblasts for Cell Therapy.

BACKGROUND AND OBJECTIVE: In recent years, due to increasing number of patients with non-healing skin ulcers, skin substitutes have been used. Skin substitutes contain living cells causing faster and more effective wound healing. Therefore, research on the use of autologous and allogeneic cells such as fibroblasts in skin substitutes has attracted attentions. However, there are discrepancies in the immune responses to allogeneic fibroblasts. Therefore, we aimed to review the immune responses to allogeneic fibroblasts. METHODS: Donor fibroblasts were isolated from the skin of three rats. Nine recipient rats which were subcutaneously injected with three different regimens, were divided into three groups: Group 1; phosphate buffered saline (PBS) without cells (control), group 2: allogeneic fibroblasts of one animal source suspended in phosphate buffered saline, and group 3; phosphate buffered saline containing mixed allogeneic fibroblasts of three animal sources. The skin samples were biopsied at 1, 3 and 7 days after injection and studied histopathologically. RESULTS AND CONCLUSION: No signs of redness and edema were observed in the injection sites. In pathology examination, changes such as vasculitis, eosinophils and lymphocytes accumulation around fibroblasts, fibroblast apoptosis and transplant rejection at the injection site were not observed in either group.Subcutaneous injection of allogeneic fibroblasts in rats can be introduced as a promising approach for wound healing as they do not stimulate the immune system.