Abstract
BACKGROUND: Injectable augmentation gels are widely used in the treatment of soft tissue. The composition of these gels has to be continuously improved due to the limitations of the currently available formulations. AIMS: This study focuses on the development of an innovative injectable gel designed to address current trends and specific needs within the field. METHODS: The current study utilized a safer hyaluronic acid (HA) gel carrier, created with a less toxic cross-linker, in combination with polycaprolactone (PCL) microspheres at various concentrations. PCL microspheres were prepared using an emulsification-solvent evaporation technique. Six different gel formulations were developed using PCL microspheres and biphasic HA gel structures. RESULTS: The produced microspheres had non-agglomerated, smooth surfaces with an average particle size of approximately 45 ± 0.14 μm. The rheological results of the PCL-HA6 such as storage modulus (G', Pa), loss modulus (G", Pa), complex viscosity (η*), and phase angle (°) at 1 Hz frequency were measured as 553.97 ± 32.48, 368.4 ± 12.24, 105.9 ± 5.27, and 33.65 ± 0.92, respectively, and the injection force was measured as 9.64 ± 1.46. In vitro tests revealed that the PCL-HA6 group showed the highest cell viability compared to the other groups and provided a relative increase in collagen production over time, as demonstrated by the relevant gene expression. CONCLUSIONS: The developed PCL/HA gel exhibited biocompatibility and non-toxicity, making it a safe option for soft tissue augmentation. It demonstrated potential for medical applications and exhibited favorable rheological characteristics and injectability.