Biodegradable polydioxanone and poly(l/d)lactide implants: an experimental study on peri-implant tissue response.

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Ophthalmic Surgery

Background:

• Current orbital wall fracture implants have limitations including resorption, migration, and foreign body reactions.
• Bioresorbable alloplastic implants offer advantages like avoiding removal surgery and donor site morbidity.

Purpose of the Study:

• To evaluate the foreign body reaction, capsule formation, and mechanical properties of two bioresorbable implants: PDS and SR-P(L/DL)LA 70,96.
• To assess the suitability of these implants for orbital wall reconstruction.

Main Methods:

• Subcutaneous implantation of PDS and SR-P(L/DL)LA 70,96 implants in 24 rats.
• Immunohistochemistry for Tn-C, alpha-actin, collagens I/III, T-cells, and monocyte/macrophages.
• GPC, DSC, SEM for material characterization; statistical analysis using Student's t-test or Kruskal-Wallis test.

Main Results:

• Both implants showed minimal foreign body reaction with distinct peri-implant capsule zones.
• SR-P(L/DL)LA 70,96 implants maintained shape and mechanical integrity over 7 months, unlike PDS which deformed within 2 months.
• SR-P(L/DL)LA 70,96 exhibited slower degradation and longer resorption time compared to PDS.

Conclusions:

• PDS implants are mechanically inadequate for orbital wall reconstruction due to rapid deformation and degradation.
• The SR-P(L/DL)LA 70,96 implant demonstrates mechanical adequacy and suitable resorption profile for orbital wall reconstruction.
• This novel polylactide copolymer implant has the potential to support orbital contents during bone regeneration.