Experimental investigation of biostimulatory effects after polydioxanone thread insertion in a pig model

Background: Polydioxanone (PDO) threads have been widely used to tighten and lift the facial soft tissue.

Objective: This research aims to determine the collagenation and inflammation changes that occur in the adipose tissue over time when different types of threads are implanted.

Methods & materials: Three threads types, PDO, poly glycolic-co-lactic acid (PGLA), and nylon, were inserted in the subcutaneous fat of 12-month-old Bama miniature pigs. Collagen production and inflammatory response were evaluated by hematoxylin and eosin and Masson trichrome staining at 1, 4, 12, 24, and 48 weeks.

Results: The integrity of the PDO thread lasted up to 24 weeks with mild inflammation and collagen production. The PGLA thread integrity lasted until 12 weeks and had a strong inflammatory response. The nylon thread's integrity was maintained for 48 weeks and showed minor inflammation and collagen production.

Conclusion: Our data suggest that PDO thread is the best choice for clinicians, as it has a mild action process with minimal irritation, moderate collagen production, a reasonable explanation time, with obvious bridging fibrous tissue, and thickening action for the superficial fascia.