Current progress in engineered and nano-engineered mesenchymal stem cells for cancer: From mechanisms to therapy.

Mesenchymal stem cells (MSCs), as self-renewing multipotent stromal cells, have been considered promising agents for cancer treatment. A large number of studies have demonstrated the valuable properties of MSC-based treatment, such as low immunogenicity and intrinsic tumor-trophic migratory properties. To enhance the potency of MSCs for therapeutic purposes, equipping MSCs with targeted delivery functions using genetic engineering is highly beneficial. Genetically engineered MSCs can express tumor suppressor agents such as pro-apoptotic, anti-proliferative, anti-angiogenic factors and act as ideal delivery vehicles. MSCs can also be loaded with nanoparticle drugs for increased efficacy and externally moderated targeting. Moreover, exosomes secreted by MSCs have important physiological properties, so they can contribute to intercellular communication and transfer cargo into targeted tumor cells. The precise role of genetically modified MSCs in tumor environments is still up for debate, but the beginning of clinical trials has been confirmed by promising results from preclinical investigations of MSC-based gene therapy for a wide range of malignancies. This review highlights the advanced techniques of engineering/nano-engineering and MSC-derived exosomes in tumor-targeted therapy.

Improving the properties of fish skin collagen/silk fibroin dressing by chemical treatment for corneal wound healing.

Natural biomaterials are crucial in ocular tissue engineering because they allow cells to proliferate, differentiate, and stratify while maintaining the typical epithelial phenotype. In this study, membranes as dressings were formed from silk fibroin and collagen (Co) extracted from fish skin and then modified with carbodiimide chemical cross linker in different concentrations. The samples were evaluated by different analyses such as structural, physical (optical, swelling, denaturation temperature, degradation), mechanical, and biological (viability, cell adhesion, immunocytochemistry) assays. The results showed that all membranes have excellent transparency, especially with higher silk fibroin content. Increasing the cross linker concentration and the ratio of silk fibroin to Co increased the denaturation temperature and mechanical strength and, conversely, reduced the degradation rate and cell adhesion. The samples did not show a significant difference in toxicity with increasing cross linker and silk fibroin ratio. In general, samples with a low silk fibroin ratio combined with cross linker can provide desirable properties as a membrane for corneal wound healing.

Recent Emerging Trend in Stem Cell Therapy Risk Factors.

Different types of stem cells have remarkable characteristics such as high proliferation rate, multi/pluripotency, self-renewal, and broad differentiation that can effectively treat diseases, cancers, and damage. Despite abundant therapeutic applications of stem cells in medical science, numerous risks threaten stem cell transplantation. Tumor development, immune response, cellular senescence, dosage effects, and administration timing are critical risks that should be considered in stem cell therapy. Hence, an investigation of possible risks is required before utilizing stem cell-based medicinal products in the clinical phase and human trials. This review aims to survey the literature and perspectives on the advantages and risks associated with pluripotent and multipotent stem cells.

Chemical modification of acellular fish skin as a promising biological scaffold by carbodiimide cross-linker for wound healing.

Biological matrices can be modified with cross-linkers to improve some of their characteristics as scaffolds for tissue engineering. In this study, chemical cross-linker 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) was used with different ratios (5, 10, 20, 30, and 40 mM) to improve properties such as mechanical strength, denaturation temperature, and degradability of the acellular fish skin as a biological scaffold for tissue engineering applications. Morphological analysis showed that the use of cross-linker at low concentrations had no effect on the structure and textiles of the scaffold, while increasing mechanical strength, denaturation temperature, and degradation time. Cytotoxicity and cellular studies showed that the optimal cross-linker concentration did not significantly affect cell viability as well as cell adhesion. In general, utilising the carbodiimide cross-linker with the optimal ratio can improve the characteristics and function of the biological tissues such as acellular fish skin.

Platelet-rich fibrin (PRF) gel modified by a carbodiimide crosslinker for tissue regeneration.

Platelet-rich fibrin (PRF) as a rich source of effective growth factors has been used as a scaffold in tissue regeneration. It is known that PRF exhibits rapid degradability against enzymes, which should be decreased using crosslinking agents to reduce the release rate of growth factors and increase the effectiveness of tissue regeneration. In this study, a carbodiimide crosslinker with different concentrations (0.01%, 0.05%, 1%, and 2%) was used to modify and improve the properties of PRF gel. The crosslinked gels were evaluated with analyses such as SEM, swelling, degradability, mechanical strength, release test, cytotoxicity, and cell adhesion. The results showed that with increasing crosslinker concentration, the morphology of the fiber structure changes drastically, the swelling rate decreases from 300% (control) to 160% for the crosslinked gel, the degradation time for the control sample increases from 8 days to more than two weeks for the crosslinked gel, and the Young's modulus increases from 0.15 MPa (control) to 0.61 MPa for the crosslinked samples. Growth factors also showed lower release with increasing crosslinking ratio. Cytotoxicity assays demonstrated that by increasing the crosslinker concentration to 1% w/v, no cytotoxicity was observed. Cellular studies with DAPI staining showed that the cells penetrated well into the gels and were well distributed, especially in gels with lower crosslinker concentrations. In addition, the modified PRF gel can be used as a scaffold for tissue regeneration.

Umbilical Cord Mesenchymal Stem/Stromal Cells Potential to Treat Organ Disorders; An Emerging Strategy.

Currently, Mesenchymal Stem/Stromal Cells (MSCs) have attracted growing attention in the context of cell-based therapy in regenerative medicine. Following the first successful procurement of human MSCs from Bone Marrow (BM), these cells isolation has been conducted from various origins, in particular, the Umbilical Cord (UC). Umbilical Cord-Derived Mesenchymal Stem/Stromal Cells (UC-MSCs) can be acquired by a non-invasive plan and simply cultured, and thereby signifies their superiority over MSCs derived from other sources for medical purposes. Due to their unique attributes, including self-renewal, multipotency, and accessibility concomitant with their immunosuppressive competence and lower ethical concerns, UC-MSCs therapy is described as encouraging therapeutic options in cell-based therapies. Regardless of their unique aptitude to adjust inflammatory response during tissue recovery and delivering solid milieu for tissue restoration, UC-MSCs can be differentiated into a diverse spectrum of adult cells (e.g., osteoblast, chondrocyte, type II alveolar, hepatocyte, and cardiomyocyte). Interestingly, they demonstrate a prolonged survival and longer telomeres compared with MSCs derived from other sources, suggesting that UC-MSCs are desired source to use in regenerative medicine. In the present review, we deliver a brief review of UC-MSCs isolation, expansion concomitantly with immunosuppressive activities, and try to collect and discuss recent pre-clinical and clinical researches based on the use of UC-MSCs in regenerative medicine, focusing on with special focus on in vivo researches.

Cell-based Therapy for Ocular Disorders: A Promising Frontier.

As the ocular disorders causing the long-term blindness or optical abnormalities of the ocular tissue entirely affect life quality, an insight into their corresponding pathogenesis and the expansion of attitudes authorizing earlier detection and treatment need more consideration. Though current therapeutics result in desirable outcomes, they do not offer an inclusive solution for hindrance of development of visual impairment to blindness. Accordingly, stem cells because of their particular competencies have attracted pronounced attention to be applied in regenerative medicine of ocular diseases. In the last decades, a wide spectrum of stem cells surrounding Mesenchymal Stem/Stromal Cells (MSC), Neural Stem Cells (NSCs), and embryonic/induced pluripotent stem cells (ESCs/iPSCs) accompanied by Müller glia, ciliary epithelia-derived stem cells, and Retinal Pigment Epithelial (RPE) stem cells have been widely investigated to report their safety and efficacy in preclinical models and also human subjects. In this regard and the first interventions, RPE cell suspensions were successfully utilized to ameliorate visual defects of the patients suffering from Age-related Macular Degeneration (AMD) after subretinal transplantation. Herein, we will explain the pathogenesis of ocular diseases and highlight the novel discoveries and recent findings in the context of stem cell-based therapies in these disorders, focusing on the last decade's in vivo reports.

Investigating the effect of structural transition on aggregation of ß-lactoglobulin.

ß-lactoglobulin (BLG), the major bovine whey protein, is a well-characterized globular protein. It is a model protein for studying the structural transition and aggregation. BLG unfolds and aggregates through chemical and physical processes. It is a predominantly ß-sheet protein but, the non-native α-helical intermediate accumulates in its folding pathway. The present study aims to understand more about which stage of the protein folding is prone to aggregation. The intermediate states were trapped by TFE and their aggregation and structural changes evaluated, for this purpose. The experiments were carried out at various pH values, ionic strengths, protein concentrations and heating times by turbidity measurements, circular dichroism and fluorescence spectroscopy. Furthermore, the aggregated species at various molecular weights were detected by SDS-PAGE. Only a small change was observed in the secondary and tertiary structures of the protein at 10% TFE, but a further increase of TFE concentration results in induction of new α-helical structure and disruption of the rigid tertiary structure. The turbidity measurement indicated that the aggregation of BLG reaches a maximum level at 10% TFE on all experimental conditions and from this point forward, it decreases with increasing the amount of TFE. In conclusion, the results showed that the α-helical state is resistant to aggregation, in spite that its tertiary structure is partially unfolded. BLG becomes prone to aggregation, when its non-native α-helical structure converts to the ß-sheet structure.