Wound healing with alginate/chitosan hydrogel containing hesperidin in rat model

Skin damages have always been considered as one of the most common physical injuries. Therefore, many researches have been conducted to find an efficient method for wound healing. Since hydrogels have suitable characteristics, they are widely used for this purpose. In this study, based on the high efficiency of alginate and chitosan hydrogels in the wound healing, different concentrations of hesperidin were loaded to alginate and chitosan hydrogels followed by evaluating their morphology, swelling properties, release, weight loss, hemo- and cytocompatibility, antibacterial and toxicity properties. Finally, the therapeutic function of the prepared hydrogels was evaluated in the full-thickness dermal wound in a rat model. Our results indicated that the hydrogels have appropriate porosity (91.2 ± 5.33) with the interconnected pores. Biodegradability of the prepared hydrogel was confirmed with weight loss assessment (almost 80 after 14 days). Moreover, the time-kill assay showed the antibacterial properties of hydrogels, and MTT assay revealed the positive effect of hydrogels on cell proliferation, and they have no toxicity effect on cells. Also, the in vivo results indicated that the prepared hydrogels had better wound closure than the gauze-treated wound (the control group), and the highest wound closure percentage was observed for the alginate/chitosan/10 hesperidin group. All in all, this study shows that alginate/chitosan hydrogels loaded with 10 of hesperidin can be used to treat skin injuries in humans. © 2019 Elsevier B.V

Hesperidin promotes peripheral nerve regeneration based on tissue engineering strategy using alginate/chitosan hydrogel: in vitro and in vivo study

About 2.8 of trauma patients suffer from peripheral nerve injury and it becomes a serious challenge in the world. Therefore, various methods and materials have been used for regenerating peripheral nerve damages. The aim of this study is to evaluate the effect of different dosages of Hesperidin on peripheral nerve regeneration. For this purpose, different concentration (0.1, 1, and 10 (w/v)) of Hesperidin was loaded into cross-linked alginate/chitosan hydrogel and its characters such as morphology, swelling properties, weight loss, hemo-, and cytocompatibility were evaluated. For functional analysis, the fabricated hydrogels without and with different amounts of hesperidin were administrated after creating sciatic nerve injury in a rat model, and the various experiments like walking-foot-print analysis, Hot plate latency test, gastrocnemius muscle wet weight loss, and histopathological examination were used. Our results indicated that prepared hydrogels contained the porosity of 90, with the interconnected pores. Biodegradability of fabricated hydrogels was confirmed with weight loss assessment and the weight loss percentage was about 80 after 14 days. Moreover, hydrogels had good blood compatibility and antibacterial properties. The MTT assay indicated that the developed hydrogels do not have toxicity effect and they have ability to increase the proliferation rate of Olfactory Ecto-mesenchymal stem cells (OE-MSCs). The results of in vivo study showed that hesperidin specially the group contained 1 of hesperidin improve sciatic nerve regeneration and hesperidin could be considered as a potential material for peripheral nerve regeneration. © 2020 Taylor & Francis Group, LLC

Alginate/chitosan hydrogel containing olfactory ectomesenchymal stem cells for sciatic nerve tissue engineering

Regeneration and functional recovery after peripheral nerve damage still remain a significant clinical problem. In this study, alginate/chitosan (alg/chit) hydrogel was used for the transplantation of olfactory ectomesenchymal stem cells (OE-MSCs) to promote peripheral nerve regeneration. The OE-MSCs were isolated from olfactory mucosa biopsies and evaluated by different cell surface markers and differentiation capacity. After creating sciatic nerve injury in a rat model, OE-MSCs were transplanted to the injured area with alg/chit hydrogel which was prepared and well-characterized. The prepared hydrogel had the porosity of 91.3 ± 1.27, the swelling ratio of 379 after 240 min, weight loss percentages of 80 ± 5.56 after 14 days, and good blood compatibility. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, 4�,6-diamidino-2-phenylindole, and LIVE/DEAD staining were done to assay the behavior of OE-MSCs on alg/chit hydrogel and the results confirmed that the hydrogel can provide a suitable substrate for cell survival. For functional analysis, alg/chit hydrogel with and without OE- MSCs was injected into a 3-mm sciatic nerve defect of Wistar rats. The results of the sciatic functional index, hot plate latency, electrophysiological assessment, weight-loss percentage of wet gastrocnemius muscle, and histopathological examination using hematoxylin�eosin and Luxol fast blue staining showed that utilizing alg/chit hydrogel with OE-MSCs to the sciatic nerve defect enhance regeneration compared to the control group and hydrogel without cells. © 2019 Wiley Periodicals, Inc

Extracellular micro/nanovesicles rescue kidney from ischemia-reperfusion injury

Acute renal failure (ARF) is a clinical challenge that is highly resistant to treatment, and its high rate of mortality is alarming. Ischemia�reperfusion injury (IRI) is the most common cause of ARF. Especially IRI is implicated in kidney transplantation and can determine graft survival. Although the exact pathophysiology of renal IRI is unknown, the role of inflammatory responses has been elucidated. Because mesenchymal stromal cells (MSCs) have strong immunomodulatory properties, they are under extensive investigation as a therapeutic modality for renal IRI. Extracellular vesicles (EVs) play an integral role in cell-to-cell communication. Because the regenerative potential of the MSCs can be recapitulated by their EVs, the therapeutic appeal of MSC-derived EVs has dramatically increased in the past decade. Higher safety profile and ease of preservation without losing function are other advantages of EVs compared with their producing cells. In the current review, the preliminary results and potential of MSC-derived EVs to alleviate kidney IRI are summarized. We might be heading toward a cell-free approach to treat renal IRI. © 2018 Wiley Periodicals, Inc

From 3D printing to 3D bioprinting: the material properties of polymeric material and its derived bioink for achieving tissue specific architectures

The application of 3D printing technologies fields for biological tissues, organs, and cells in the context of medical and biotechnology applications requires a significant amount of innovation in a narrow printability range. 3D bioprinting is one such way of addressing critical design challenges in tissue engineering. In a more general sense, 3D printing has become essential in customized implant designing, faithful reproduction of microenvironmental niches, sustainable development of implants, in the capacity to address issues of effective cellular integration, and long-term stability of the cellular constructs in tissue engineering. This review covers various aspects of 3D bioprinting, describes the current state-of-the-art solutions for all aforementioned critical issues, and includes various illustrative representations of technologies supporting the development of phases of 3D bioprinting. It also demonstrates several bio-inks and their properties crucial for being used for 3D printing applications. The review focus on bringing together different examples and current trends in tissue engineering applications, including bone, cartilage, muscles, neuron, skin, esophagus, trachea, tympanic membrane, cornea, blood vessel, immune system, and tumor models utilizing 3D printing technology and to provide an outlook of the future potentials and barriers. Keywords: Bioprinting; Cell encapsulation; In-vitro technique; Perfusion; Rheology; Tissue engineering

Encapsulation of Homogeneous Catalysts in Porous Polymer Nanocapsules Produces Fast-Acting Selective Nanoreactors

Nanoreactors were created by entrapping homogeneous catalysts in hollow nanocapsules with 200 nm diameter and semipermeable nanometer-thin shells. The capsules were produced by the polymerization of hydrophobic monomers in the hydrophobic interior of the bilayers of self-assembled surfactant vesicles. Controlled nanopores in the shells of nanocapsules ensured long-term retention of the catalysts coupled with the rapid flow of substrates and products in and out of nanocapsules. The study evaluated the effect of encapsulation on the catalytic activity and stability of five different catalysts. Comparison of kinetics of five diverse reactions performed in five different solvents revealed the same reaction rates for free and encapsulated catalysts. Identical reaction kinetics confirmed that placement of catalysts in the homogeneous interior of polymer nanocapsules did not compromise catalytic efficiency. Encapsulated organometallic catalysts showed no loss of metal ions from nanocapsules suggesting stabilization of the complexes was provided by nanocapsules. Controlled permeability of the shells of nanocapsules enabled size-selective catalytic reactions