Correction: Left Ventricular Geometry and Angiogenesis Improvement in Rat Chronic Ischemic Cardiomyopathy following Injection of Encapsulated Mesenchymal Stem Cells.

In this article published in Cell J, Vol 24, No 12, 2022, on pages 741-747, the authors found that there was some mistakes in the Table 1 and we have corrected them in the following table. The authors would like to apologize for any inconvenience.

Preparation and in vitro evaluation of biological agents based on Zinc-laponite- curcumin incorporated in alginate hydrogel.

Due to their outstanding structures and properties, three-dimensional (3D) hydrogels and nanoparticles have been widely studied and indicated a very high potential for medical, therapeutic, and diagnostic applications. However, hydrogels and nanoparticles systems have particular drawbacks that limit their widespread applications. In recent years, the incorporation of nanostructured systems into hydrogel has been developed as a novel way for the formation of new biomaterials with various functions to solve biomedical challenges. In this study, alginate-loaded Zinc- laponite-curcumin (Zn/La/Cur) nanocomposites were fabricated via ionic cross-linking. The prepared nanocomposite hydrogels were characterized via FTIR and FE-SEM. Moreover, energy dispersive x-ray spectroscopy (EDX) was used to study the elements of the Zn/La/Cur nanocomposite. The NIH3T3 fibroblast cell line was utilized for the MTT assay to determine the cell viability of the fabricated alginate-loaded Zn/La/Cur nanocomposites. MTT results demonstrated that there was no evidence of toxicity in the samples. These outcomes suggest that applying Al/Zn/La/Cur nanocomposite as a biological agent could be a novel tissue engineering strategy for treating soft tissue disorders.

Preparation and characterization of propolis reinforced eggshell membrane/ GelMA composite hydrogel for biomedical applications.

Gelatin methacrylate-based hydrogels (GelMA) were widely used in tissue engineering and regenerative medicine. However, to manipulate their various chemical and physical properties and create high-efficiency hydrogels, different materials have been used in their structure. Eggshell membrane (ESM) and propolis are two nature-derived materials that could be used to improve the various characteristics of hydrogels, especially structural and biological properties. Hence, the main purpose of this study is the development of a new type of GelMA hydrogel containing ESM and propolis, for use in regenerative medicine. In this regard, in this study, after synthesizing GelMA, the fragmented ESM fibers were added to it and the GM/EMF hydrogel was made using a photoinitiator and visible light irradiation. Finally, GM/EMF/P hydrogels were prepared by incubating GM/EMF hydrogels in the propolis solution for 24 h. After various structural, chemical, and biological characterizations, it was found that the hydrogels obtained in this study offer improved morphological, hydrophilic, thermal, mechanical, and biological properties. The developed GM/EMF/P hydrogel presented more porosity with smaller and interconnected pores compared to the other hydrogels. GM/EMF hydrogels due to possessing EMF showed compressive strength up to 25.95 ± 1.69 KPa, which is more than the compressive strength provided by GM hydrogels (24.550 ± 4.3 KPa). Also, GM/EMF/P hydrogel offered the best compressive strength (44.65 ± 3.48) due to the presence of both EMF and propolis. GM scaffold with a contact angle of about 65.41 ± 2.199 θ showed more hydrophobicity compared to GM/EMF (28.67 ± 1.58 θ), and GM/EMF/P (26.24 ± 0.73 θ) hydrogels. Also, the higher swelling percentage of GM/EMF/P hydrogels (343.197 ± 42.79) indicated the high capacity of this hydrogel to retain more water than other scaffolds. Regarding the biocompatibility of the fabricated structures, MTT assay results showed that GM/EMF/P hydrogel significantly (p-value < 0.05) supported cell viability. Based on the results, it seems that GM/EMF/P hydrogel could be a promising biomaterial candidate for use in various fields of regenerative medicine.

Left Ventricular Geometry and Angiogenesis Improvement in Rat Chronic Ischemic Cardiomyopathy following Injection of Encapsulated Mesenchymal Stem Cells.

OBJECTIVE: Injection of hydrogel and cells into myocardial infarction (MI) patients is one of the emerging treatment techniques, however, it has some limitations such as a lack of electromechanical properties and neovascularization. We investigated the therapeutic potential of new electroactive hydrogel [reduced graphene oxide (rGO)/Alginate (ALG)] encapsulated human bone marrow mesenchymal stem cells (BMSCs). MATERIALS AND METHODS: The experimental study involved ligating the left anterior descending coronary artery (LAD) in rat models of chronic ischemic cardiomyopathy. Echocardiograms were analyzed at 4 and 8 weeks after MI treatment. In the eighth week after injection in the heart, the rats were sacrificed. Histological and immunohistochemical analyses were performed using Hematoxylin and Eosin (H and E) staining, Masson's trichrome staining and anti-CD31 antibody to analyze tissue structure and detect neovascularization. RESULTS: In comparison to the control and other treatment groups, MSCs encapsulated in rGO-ALG showed significant improvements in fractional shortening (FS), ejection fraction (EF), wall thickness and internal diameters (P<0.05). The morphological observation showed several small blood vessels formed around the transplantation site in all treated groups especially in the MSC-ALG-rGO group 8 weeks after the transplantation. Also, Masson's trichrome staining indicated an increased amount of collagen fibers in rGO-ALG-MSC. Microvessel density was significantly higher using MSC-ALG-rGO compared to controls (P<0.01). CONCLUSION: This study demonstrates that intramyocardial injection of rGO/ALG, a bio-electroactive hydrogel, is safe for increasing LV function, neovascularization, and adjusting electrical characteristics following MI. The results confirm ALG promising capability as a natural therapeutic for cardiac regeneration.