www.elsevier.com/locate/jmbbm Available online at www.sciencedirect.com Research Paper Rheological characterization of a gel produced using human blood plasma and alginate mixtures Dionisio Malago ´ n-Romero a,b,n , Nicola ´ s Herna ´ ndez a , Carmen Cardozo a , Rube ´n D. Godoy-Silva a a Universidad Nacional de Colombia, Bogotá, Colombia b Universidad Santo Tomás, Bogotá, Colombia article info Article history: Received 23 November 2013 Received in revised form 4 February 2014 Accepted 5 February 2014 Available online 12 February 2014 Keywords: Alginate Fibrin Gel Plasma proteins abstract Human blood plasma is a material used to generate tissue equivalents due to presence of fibrinogen. However, gels formed using human blood plasma has weak mechanical proper- ties. In this study, different mixtures of sodium alginate and blood plasma were performed and evaluated. By determining ζ potential can be established the stability of the plasma– alginate mixture and by dynamic rheology can determine the most suitable parameters for the gelation of the above mixtures, when calcium chloride is used as a crosslinker. Experimental results evidence an increment in ζ potential at alginate concentrations of 0.8% and 1.6% with a resulting pseudoplastic behavior of evaluated mixtures, which described the homogenization of the mixture. On the other hand, mixtures were gelled by using aspersion of calcium chloride and characterized by dynamic rheology. Solid behavior is dominant in all range of frequency sweep test between 0.1 Hz and 100 Hz. Finally, the ultimate tensile strength of a gel reach 6.3693870.24320 kPa, which is enough for manual handling of the gel. Between the tasks of the gel would be used for cell entrapment, for controlled release of drugs or in the manufacture of wound dressings. & 2014 Elsevier Ltd. All rights reserved. 1. Introduction Although many materials have been evaluated and used in generation of temporary scaffolds for cells growth in tissue engineering (Yoon and Fischer, 2007; Pachence et al., 2007; Warren et al, 2004), research community prefer the use of biocompatible and biodegradable materials (Falke and Atala, 2000). These kind of materials enhance cell adhesion and signal capabilities (Sukmana, 2012). Natural polymers provide these properties mentioned above. They can be divided in two major groups: proteins such as collagen, gelatin, albumin, fibrinogen, and polysac- charides like chitosan, hyaluronic acid, alginate, cellulose and dextran. The mixture of polysaccharides and proteins for generating tissue scaffolds gives a promising combination of good mechanical strength provided by polysaccharides and the cell adhesion capabilities of proteins. Particularly, Fibrinogen has gained status in tissue engi- neering due to its ease of acquisition and its ability to generate diverse and different scaffolds. This material can be obtained either, from a patient's own blood plasma, blood bank plasma, or from commercial sources (e.g., Tissel s , Baxter Laboratories). http://dx.doi.org/10.1016/j.jmbbm.2014.02.012 1751-6161 & 2014 Elsevier Ltd. All rights reserved. n Corresponding author. Tel.: þ57 3012026284. E-mail address: dionisiomalagon@usantotomas.edu.co (D. Malagón-Romero). journal of the mechanical behavior of biomedical materials 34(2014)171–180