Collagen modification by Maillard reaction

Collagen is widely studied in the pharmaceutical field as a biomaterial for drug delivery systems. Generally, for this purpose, collagen is used in the cross-linked form. However, substances such as glutaraldehyde and formaldehyde, which can present cytotoxicity, have been used to achieve cross-linking in these molecules. The objective of the present paper was the extraction and purification of the collagen and its modification by the Maillard reaction. This reaction uses reducing sugars as cross-linking agents with the purpose of eliminating the use of toxic aldehydes. The unmodified collagen and glycated collagen were characterized by electrophoresis in polyacrylamide gel (SDS-PAGE), FTIR spectroscopy, thermal analysis, and by the determination of the NH2-linking degree. The glycated collagen and unmodified collagen were also evaluated in the gel form for their rheological behavior and drug delivery profiles. The SDS-PAGE results showed that the extraction and purification were efficient. Additionally, the thermogravimetric analysis and NH2-linking degree indicated that the reaction had occurred. The rheological assays indicated a higher viscosity for the glycated collagen gel with an increase in the yield at 25 °C. Related to the drug delivery, the results suggested that the increase in collagen concentration in the gel promotes a higher retention time of acetaminophen in the system. The unmodified collagen gel showed a better drug delivery profile than the glycated collagen gel.