|BERLANGA-REYES, C - CENTER FOR RESEARCH IN FOOD AND DEVELOPMENT (CIAD)|
|CARVAJAL-MILLAN, E - CENTER FOR RESEARCH IN FOOD AND DEVELOPMENT (CIAD)|
|RASCONCHU, AGUSTIN - CENTER FOR RESEARCH IN FOOD AND DEVELOPMENT (CIAD)|
|LIZARDI-MENDOZA, JAIME - CENTER FOR RESEARCH IN FOOD AND DEVELOPMENT (CIAD)|
|ISLAS-RUBIO, ALMA - CENTER FOR RESEARCH IN FOOD AND DEVELOPMENT (CIAD)|
Submitted to: International Journal of Molecular Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/22/2014
Publication Date: 10/21/2014
Publication URL: https://handle.nal.usda.gov/10113/60401
Citation: Berlanga-Reyes, C., Carvajal-Millan, E., Hicks, K.B., Yadav, M.P., Rasconchu, A., Lizardi-Mendoza, J., Islas-Rubio, A.R. 2014. Protein/Arabinoxylans Gels: Effect of mass ratio on the rheological, microstructural and diffusional characteristics. International Journal of Molecular Sciences. 15:19106-19118.
Interpretive Summary: We are looking for new uses for wheat bran, a surplus by-product of the commercial wheat milling process. We have found that wheat bran contains a special polysaccharide (complex carbohydrate) called “arabinoxylan”. This arabinoxylan can form water-insoluble gels when it is processed in a certain way. We wondered if we could cause the arabinoxylan to form these gels in the presence of various types of drug molecules so that the drug would be entrapped inside the gel and then could be released at a later time when needed. An example of a potential use of this technology could be for colon cancer treatment. A colon cancer specific drug can be entrapped in the gel and then the gel could be swallowed by the patient. The gelled carbohydrate polymer is not digestible in the stomach and small intestine. So it will easily pass into the large intestine (colon) without any change, where it will be digested and degraded by colonic bacteria, allowing the drug to be released at that site. In this way, a colon specific drug can be easily released at this site without affecting any other part of the digestive system. Model “drugs” used in this study were incorporated easily into these gels, which can now be used in further laboratory and clinical studies to show their release under colon-type conditions. If successful, these findings will aid patients being treated for colon-cancer. It will also benefit U.S. wheat growers and processors by creating new uses and added value for wheat bran.
Technical Abstract: Arabinoxylan (AX) gels entrapping standard model proteins at different mass ratios were formed. The distribution of protein through the network was investigated by confocal laser scanning microscopy (CLSM). In mixed gels, protein aggregates forming clusters were detected at protein/polysaccharide ratios higher than 0.25. These clusters were not homogenously distributed, suggesting that AX and protein are located in two different phases. The apparent diffusion coefficient (Dm) of proteins during release from mixed gels was investigated for mass ratios of 0.06 and 0.12. For insulin, Dm increased significantly from 2.64 x 107 to 3.20 x 107 cm2/s as the mass ratio augmented from 0.06 to 0.12. No significant difference was found for Dm values of ovalbumin and bovine serum albumin (BSA) released from the mixed gels. The results indicate that homogeneous protein/AX gels can be formed at low mass ratios, allowing the estimation of Dm by using an analytical solution of the second Fick’s law.