Tissue microenvironment affects the performance of implanted biomaterials, suggesting that one implant composition won’t work for all applications, according to a report in Science Translational Medicine (2015, DOI: 10.1126/scitranslmed.aaa1616). Natalie Artzi of MIT and Harvard Medical School and coworkers assessed interactions between an adhesive biomaterial and healthy or diseased colon tissue. The biomaterial is a hydrogel formed from the reaction of dendrimer amines and dextran aldehyde. It functions as an adhesive by reacting with amines in proteins on tissue surfaces. The number of available surface amines determines how strongly the biomaterial holds tissue together. The researchers tested the biomaterial in a rat model of colon cancer and a rabbit model of inflammatory colitis. The adhesive holds cancer tissue together better than healthy tissue because the cancerous one has more surface amines. In contrast, in inflamed tissue, adhesion decreases with increasing severity of the disease. By using a fluorescence assay to determine the distribution of surface amines in tissues, the researchers were able to tune adhesion by adjusting the composition of the biomaterial. “Rational design of biomaterials with an eye toward patient-specific tailored materials is the next step in precision medicine that would potentially lead to improved clinical outcomes,” Artzi says.