Rev Chem Eng 2016; 32(6): 629–650 *Corresponding author: Diganta Bhusan Das, Department of Chemical Engineering, Loughborough University, Leicestershire LE11 3TU, UK, e-mail: D.B.Das@lboro.ac.uk Hazwani Suhaimi: Department of Chemical Engineering, Loughborough University, Leicestershire LE11 3TU, UK Hazwani Suhaimi and Diganta Bhusan Das* Glucose diffusion in tissue engineering membranes and scaffolds DOI 10.1515/revce-2015-0021 Received April 8, 2015; accepted August 28, 2015; previously published online June 7, 2016 Abstract: Tissue engineering has evolved into an excit- ing area of research due to its potential in regenerative medicine. The shortage of organ donors as well as incom- patibility between patient and donor pose an alarming concern. This has resulted in an interest in regenerative therapy where the importance of understanding the trans- port properties of critical nutrients such as glucose in numerous tissue engineering membranes and scaffolds is crucial. This is due to its dependency on successful tissue growth as a measure of potential cure for health issues that cannot be healed using traditional medical treatments. In this regard, the diffusion of glucose in membranes and scaffolds that act as templates to support cell growth must be well grasped. Keeping this in mind, this review paper aims to discuss the glucose diffusivity of these materials. The paper reviews four interconnected issues, namely, (i) the glucose diffusion in tissue engineering materials, (ii) porosity and tortuosity of these materials, (iii) the rela- tionship between microstructure of the material and diffu- sion, and (iv) estimation of glucose diffusivities in liquids, which determine the effective diffusivities in the porous membranes or scaffolds. It is anticipated that the review paper would help improve the understanding of the trans- port properties of glucose in membranes and scaffolds used in tissue engineering applications. Keywords: diffusion; glucose; membrane; scaffold; tissue engineering. 1 Introduction Organ shortage and failures due to accidental and illness incidences have been a concern in almost every part of the world. Organ transplantation has been a common practice in clinical settings and has been reported to be successful as early as the 1960s (Couch et al. 1966). Although it has been perceived to be successful, it also has its limitations, e.g. long patient waiting time and death of organ donors (Liu et al. 2013, Guo and Ma 2014). To overcome these limitations, engineers, biologists, chemists, and material experts have come together to create the tissue engineer- ing (TE) approach as an alternative to organ transplanta- tion, which provides a cost-effective treatment, resulting in improved health care and quality of lives of the patients. TE is therefore defined as a multidisciplinary field that helps to repair, replace, and restore the original functions of damaged tissues (Langer and Vacanti 1993, Liu et al. 2013). A simple illustration of TE principles is shown in Figure 1. As the figure shows, TE approach aims to mimic the in vivo environment to help in cell proliferation and dif- ferentiation into tissues and consequently tissue regenera- tion (Tabata 2014). In brief, living cells are harvested from a patient’s body of relative excess followed by expansion of these cells in vitro. The cells are then loaded on tissue engi- neered scaffolds, which act as a template for cell growth in a process known as cell seeding. The cells are grown with the supply of nutrients (e.g. glucose and oxygen) and monitored for its physiologically relevant standards for bone TE (BTE) in terms of cell-cell and cell-matrix interac- tions as well as possessing the nanostructural and chemi- cal extracellular matrices (ECMs) (Zhu et al. 2015) as found in the native ECM of the body. Surgical implantations into the host body are carried out, and finally, the functionality of the regenerated tissue is observed in vivo. Due to its numerous successes, TE has become the leading choice in the field of regenerative medicine (Khaled et al. 2011). The main goal of TE is to produce an alternative that can overcome the limitations of tradi- tional treatments and possess a good potential to eventu- ally form an “artificial” organ that resembles the original organ in terms of function and ability. Furthermore, it is envisaged that a TE approach presents a permanent cure without the need for follow-up therapies (Langer and Vacanti 1993, Patrick et al. 1998). For example, BTE, which has been reported since the early 1980s (Amini et al. 2012), has become a substitute for bone grafting. TE researchers have shown the possibility of growing artificial tissues both in vitro and in vivo, e.g. bone, Brought to you by | Loughborough University Authenticated Download Date | 6/8/17 11:09 AM