Introduction. Polycaprolactone scaffolds are commonly used for tissue engineering due to tunable fabrication properties, biodegradability, and biocompatibility. Although, the problem related to its wettability and the lack of functional groups that are essential for growth factor incorporation, remains. In this research ozone treatment in water environmental was used to enhance PCL scaffold wettability and the number of functional groups. Since IGF-1 is positively charged it can be incorporated to the PCL scaffold through functional groups occurred after treatment.
Materials and methods. The present study investigated the effect of ozone treatment to IGF-1 release kinetics. IGF-1 release was analysed using ELISA method and further investigation of release profile kinetics was performed using four mathematical models: the zero-order, first-order, Hixson–Crowell, and Higuchi. Coefficient of determination (R2) value was generated using simple linear regression. According to R2 best fitted mathematical model was used to calculate the release constants (k) for different treatment duration IGF-1 release profiles. The rate of IGF-1 release from scaffold was then compared according to k values.
Results. The IGF-1 release profile had two distinct stages: an initial burst and slow sustained release. The majority of IGF-1 was not released, demonstrating that there was a strong interaction between IGF-1 and the scaffold. Such release kinetics was approximated by Higuchi model, which suggested that the release constant (k) decreased with increasing treatment duration indicating slower release of IGF-1.
Conclusion. The release profiles of IGF-1 in all samples achieved the best fit with the Higuchi model, as indicated by the highest value of R2. Higuchi model shows that release of growth factor is time dependent and diffusion-controlled process. All observations suggest that O3 treatment could be used to release IGF-1 in a controllable and sustained manner.