Liquid-Form Polycaprolactone Injection Enhances Dermal Thickness and Collagen Production in UVB-Induced Photoaging Skin

This is an animal study evaluating the effects of liquid polycaprolactone (PCL) injection on dermal thickness and collagen production in a photoaged skin model induced by UVB. 40 Wistar rats were divided into a control group and a UVB irradiation group. The UVB irradiation group was further divided into three groups: untreated control, distilled water injection, and liquid PCL injection. After 6 weeks of treatment, dermal thickness (Masson's trichrome staining), type I collagen gene expression (Col1a1), and protein levels were analyzed. The group injected with liquid PCL along with UVB showed a significant increase in dermal thickness compared to the UVB non-injection group and the distilled water injection group. Col1a1 expression and type I collagen protein levels were significantly restored to control levels, and collagen density also significantly increased. The researchers concluded that liquid PCL has potential as a therapeutic option for photoaging by promoting dermal thickness and collagen production in UVB-damaged skin.