Effects of long-term exposure of gelatinated and non-gelatinated cadmium telluride quantum dots on differentiated PC12 cells

Journal article (open access)Background: The inherent toxicity of unmodified Quantum Dots (QDs) is a major hindrance to their use in biological applications. To make them more potent as neuroprosthetic and neurotherapeutic agents, thioglycolic acid (TGA) capped CdTe QDs, were coated with a gelatine layer and investigated in this study with differentiated pheochromocytoma 12 (PC12) cells. The QD - cell interactions were investigated after incubation periods of up to 17 days by MTT and APOTOX-Glo Triplex assays along with using confocal microscopy.Results: Long term exposure (up to 17 days) to gelatinated TGA-capped CdTe QDs of PC12 cells in the course of differentiation and after neurites were grown resulted in dramatically reduced cytotoxicity compared to non-gelatinated TGA-capped CdTe QDs.Conclusion: The toxicity mechanism of QDs was identified as caspase-mediated apoptosis as a result of cadmium leaking from the core of QDs. It was therefore concluded that the gelatine capping on the surface of QDs acts as a barrier towards the leaking of toxic ions from the core QDs in the long term (up to 17 days).Science Foundation Irelandpeer-reviewe

Natural and synthetic materials for self-renewal, long-term maintenance, and differentiation of induced pluripotent stem cells

Induced pluripotent stem cells (iPSCs) have attracted considerable attention from the public, clinicians, and scientists since their discovery in 2006, and raised huge expectations for regenerative medicine. One of the distinctive features of iPSCs is their propensity to differentiate into the cells of three germ lines in vitro and in vivo. The human iPSCs can be used to study the mechanisms underlying a disease and to monitor the disease progression, for testing drugs in vitro, and for cell therapy, avoiding many ethical and immunologic concerns. This technology offers the potential to take an individual approach to each patient and allows a more accurate diagnosis and specifi c treatment. However, there are several obstacles that impede the use of iPSCs. The derivation of fully reprogrammed iPSCs is expensive, time-consuming, and demands meticulous attention to many details. The use of biomaterials could increase the effi cacy and safety while decreasing the cost of tissue engineering. The choice of a substrate utilized for iPSC culture is also important because cell-substrate contacts infl uence cellular behavior such as selfrenewal, expansion, and differentiation. This Progress Report aims to summarize the advantages and drawbacks of natural and synthetic biomaterials, and to evaluate their role for maintenance and differentiation of iPSCs

Natural and synthetic materials for self-renewal, long-term maintenance, and differentiation of induced pluripotent stem cells

Induced pluripotent stem cells (iPSCs) have attracted considerable attention from the public, clinicians, and scientists since their discovery in 2006, and raised huge expectations for regenerative medicine. One of the distinctive features of iPSCs is their propensity to differentiate into the cells of three germ lines in vitro and in vivo. The human iPSCs can be used to study the mechanisms underlying a disease and to monitor the disease progression, for testing drugs in vitro, and for cell therapy, avoiding many ethical and immunologic concerns. This technology offers the potential to take an individual approach to each patient and allows a more accurate diagnosis and specifi c treatment. However, there are several obstacles that impede the use of iPSCs. The derivation of fully reprogrammed iPSCs is expensive, time-consuming, and demands meticulous attention to many details. The use of biomaterials could increase the effi cacy and safety while decreasing the cost of tissue engineering. The choice of a substrate utilized for iPSC culture is also important because cell-substrate contacts infl uence cellular behavior such as selfrenewal, expansion, and differentiation. This Progress Report aims to summarize the advantages and drawbacks of natural and synthetic biomaterials, and to evaluate their role for maintenance and differentiation of iPSCs

Recent advances in host–guest self‐assembled cyclodextrin carriers: Implications for responsive drug delivery and biomedical engineering

This Review is an overview of the unique characteristics of cyclodextrin in forming an inclusion complex via host guest noncovalent interactions. The modification of cyclodextrin advances its application as a pharmaceutical solubilizer, fabrication of functional molecular machines such as polyrotaxane, polypseudorotaxane, and polycatenanes and grafting of cyclodextrin with different linear, branched chain polymers. The different stimuli‐based supramolecular assemblies involving cyclodextrin as a key mediator with linked triggering responses on payload release is highlighted. In addition, the applications of cyclodextrin in diagnostic imaging and medical devices is briefly demonstrated. Cyclodextrin is a relatively low cost, biocompatible, biodegradable, and highly explored material with low toxicity for drug formulation, drug delivery, and wide varieties of other biomedical applications such as those in medical devices fabrication, biosensor, tissue engineering, and bio‐imaging. The toxicological profile of cyclodextrin is well established and safe for human consumption in food and medicine.J.W., N.G.K., and S.G. contributed equally to this work. This project received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska‐Curie grant agreement No 713690. This publication was also emanated from research conducted with the financial support of Science Foundation Ireland (SFI) and is co‐funded under the European Regional Development Fund under Grant Number 13/RC/2073. S.G. would like to thank India's Ministry of Chemicals and Fertilizers for NIPER Ph.D. fellowship. The authors would also like to thank Maciej Doczyk for his help with the graphic illustrations and Anthony Sloan (Technical Writer‐English) for his careful help in finalizing the manuscript.peer-reviewe

Recent advances in host–guest self‐assembled cyclodextrin carriers: Implications for responsive drug delivery and biomedical engineering

This Review is an overview of the unique characteristics of cyclodextrin in forming an inclusion complex via host guest noncovalent interactions. The modification of cyclodextrin advances its application as a pharmaceutical solubilizer, fabrication of functional molecular machines such as polyrotaxane, polypseudorotaxane, and polycatenanes and grafting of cyclodextrin with different linear, branched chain polymers. The different stimuli‐based supramolecular assemblies involving cyclodextrin as a key mediator with linked triggering responses on payload release is highlighted. In addition, the applications of cyclodextrin in diagnostic imaging and medical devices is briefly demonstrated. Cyclodextrin is a relatively low cost, biocompatible, biodegradable, and highly explored material with low toxicity for drug formulation, drug delivery, and wide varieties of other biomedical applications such as those in medical devices fabrication, biosensor, tissue engineering, and bio‐imaging. The toxicological profile of cyclodextrin is well established and safe for human consumption in food and medicine.J.W., N.G.K., and S.G. contributed equally to this work. This project received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska‐Curie grant agreement No 713690. This publication was also emanated from research conducted with the financial support of Science Foundation Ireland (SFI) and is co‐funded under the European Regional Development Fund under Grant Number 13/RC/2073. S.G. would like to thank India's Ministry of Chemicals and Fertilizers for NIPER Ph.D. fellowship. The authors would also like to thank Maciej Doczyk for his help with the graphic illustrations and Anthony Sloan (Technical Writer‐English) for his careful help in finalizing the manuscript.peer-reviewe

Thermoresponsive substrates used for the expansion of human mesenchymal stem cells and the preservation of immunophenotype

The facile regeneration of undifferentiated human mesenchymal stem cells (hMSCs) from thermoresponsive surfaces facilitates the collection of stem cells avoiding the use of animal derived cell detachment agents commonly used in cell culture. This communication proposes a procedure to fabricate coatings from commercially available pNIPAm which is both affordable and a significant simplification on alternative approaches used elsewhere. Solvent casting was used to produce films in the micrometer range and successful cell adhesion and proliferation was highly dependent on the thickness of the coating produced with 1 mu m thick coatings supporting cells to confluence. 3T3 cell sheets and hMSCs were successfully detached from the cast coatings upon temperature reduction. Furthermore, results indicate that the hMSCs remained undifferentiated as the surface receptor profile of hMSCs was not altered when cells were detached in this manner