By taking advantage of a natural and abundant polymer as well as a straightforward film formation technique, this paper focuses on the conception and use of a new alternative tool for thermo-controlled cell detachment. Thermoresponsive xyloglucan was produced after partial galactose removal by a 24 h reaction with β-galactosidase. The obtained polymer (T24) was then activated by reaction with 4-nitrophenyl chloroformate (NPC) in order to graft a cyclic peptide presenting an arginine-glycine-aspartic acid (RGD) motif. The effect of RGD grafting on the sol-gel transition temperature of T24 is evaluated by rheological measurements. Solvent-casted films of T24-RGD successfully promoted cell adhesion, proliferation, and thermo-controlled detachment. The presented approach is a new alternative for cells sensitive to the proteolytic treatment routinely used for cell detachment. Because the RGD sequence used herein is widely recognized by different cell types, this protocol may be extended to other cells. Besides, the presented chemical route can be applied to different peptide sequences.