Biodegradable polymer coating for controlled release of hydrophobic functional molecules from cotton fabrics

Despite major advances in polymer chemistry, cotton still remains the principal textile component in the global pharmaceutical industry owing to its intrinsic strength, thermal stability, biocompatibility, and pleasant texture. Nevertheless, the hydrophilic nature of cotton requires the development of strategies for the incorporation of hydrophobic functional molecules into the fabric for controlled-release applications. To address this issue, we designed biodegradable crosslinked poly(β-amino ester) (PBAE) coatings as reservoirs for the incorporation of small hydrophobic molecules and studied their release profiles under physiological conditions. Two PBAEs with different hydrophobic and degradation properties were prepared and crosslinked to cotton fabrics in the presence of azulene, which served as a model hydrophobic, active material. Optimization of the crosslinking process in terms of UV curing time and the amount of solvent revealed that curing time of 15 min using 0.5 mL of chloroform was the optimal crosslinking condition. The coatings were characterized by FTIR, XPS, and SEM as well as TGA and DSC analyses. Sustained release of azulene was observed, and there was a correlation between azulene delivery rates and the hydrophobicity of the coating. These results provide a potentially useful platform for the rational design of cotton-based controlled-release systems for bioactive molecule delivery applications.