Tunable degradation of piperazine‐based polyurethane ureas

To manipulate the degradation of polymeric biomaterial for potential applications in tissue regeneration, a series of piperazine‐based polyurethane ureas (P‐PUUs) were designed and prepared with poly(d,l‐lactic acid) diol (PDLLA diol), 1,6‐hexamethylene diisocyanate (HDI), and piperazine (PP). The number of piperazine units [Num(pp)] in the P‐PUUs could be precisely calculated by a specified equation and could be controlled by the regulation of the PDLLA diol/HDI/PP ratio. Then, the in vitro degradation of the P‐PUUs was investigated by the detection of the variation of the pH value, the weight loss ratio, the surface morphologies, and the molecular weight loss over 12 weeks. The results reveal that the degradation stability and the degradation rate of the P‐PUUs could be manipulated by Num(pp), and a linear correlation between the degradation rate of the P‐PUUs and Num(pp) in the polymer was demonstrated; this implied the tunable degradation of the P‐PUUs. Such a linear correlation is expected to benefit to tissue regeneration as the degradation rate of P‐PUUs for specific tissue defects can be well tuned once the tissue regenerative period is known.