One of the greatest puzzles in wound healing is how to substitute or replace the defect caused by loss and damaged tissue or organs. In regenerative medicine, Tissue Engineering has been proposed to supply this demand by generating tissues in vitro. Bioreactors are the key to translate these cells and tissue-based constructs into large-scale biological products that are clinically effective, safe and financially pliable. In this review, we summarise the different up-to-date bioreactor designs being used for different cell types and special design scaffolds, and highlight advantages of different bioreactors, current challenges and the future trends. It is our belief that with efforts combined from multiple disciplinary participants, a novel bioreactor system that is capable of fast, large scale tissue culture would come about in near future. (C) 2016 Elsevier B.V. All rights reserved.

Background: The physio-chemical properties of blood contacting biomaterials play an important role in determining their hemocompatibility. It is shown in literature that surface roughness and porosity have significant effect on hemocompatibility. In this study, we use a biocompatible, low thrombogenic nanocomposite polymer called POSS-PCU to test this hypothesis: would porosity compromise the hemocompatibility of POSS-PCU. We compared the hemocompatibility of POSS-PCU films of various pore sizes with PTFE, which is a commercially available material used in most blood contacting devices.Methods: Sterilized POSS-PCU films with different size pores were prepared as samples and porous PTFE film were selected as control. And all samples were subjected to SEM for topograpgy, mechanical test for characterization and hemocompatibility tests to evaluate contact activation, platelet adhesion and activation, as well as whole blood clotting response to the samples.Results: WCA significantly increased with the pore size of POSS-PCU film, whereas both tensile stress and strain decreased significantly as the sizes of pores increased. However, when compared to PTFE film with same size pores, POSS-PCU films showed both higher tensile stress and strain. Pore size had little impact over POSS-PCU's surface chemistry groups as tested by FTIR analysis. Contact activation and platelet adhesion essay also showed no significant difference between different POSS-PCU samples. However, in whole blood reactions, POSS-PCU with pores size around 2-5 mu m showed higher BCI than plain films and those with pores size around 35-45 mu m. POSS-PCU showed lower thrombogencity and higher hemocompatibility comparing with porous PTFE on the aspects of platelet activation, adhesion and whole blood reaction.Summary and conclusions: POSS-PCU polymer films as a biomaterial in chronic blood contacting implants show significant lower thrombogencity and higher hemocompatibility than porous PTFE film. It is desirable as a coating or covering material in small diameter stents for treating cardiovascular diseases, cerebral vascular diseases and peripheral arterial diseases. (C) 2015 Published by Elsevier Ltd.

Stroke or cerebral vascular accidents are among the leading causes of death in the world. With the availability of Digital Subtraction Angiography, transluminal angioplasty has become feasible in many situations and the role of intracranial stents is becoming ever more important in the management of cerebral vascular diseases. In current review, we outline the chronological development of various stents namely; balloon expandable stent, self-expandable open cell stent, self-expandable close cell stent and the flow diverting stent. Further we discuss their advantages and limitations in terms of stent migration, thromboemboli, damage to vessels during procedure, in-stent stenosis and hyper-perfusion damage. We also discuss the importance of in-situ endothelialization, controlled expandability and hemodynamic manipulation in stent design. Further, we summarized the role and need for further development in the areas of bio-compatible materials, endothelial progenitor cell capture technique, bio-functionalized-magnetic-nano-particles and nanotechnology which are significant in intracranial stent development.