IADR Abstract Archives
Local Treatment of Liposomal Resolvin-D1: Inhibition of Periodontitis
Objectives: Periodontitis is an infectious inflammatory disease of the supporting structures of the teeth. Resolvin-D1 (RvD1) is a specialized pro-resolving lipid mediator that enhances active resolution of inflammation and osteoclastogenesis inhibition. However, RvD1 short half life and reduced in vivo retention limit its therapeutic potential. In this study, we aimed to engineer a RvD1 loaded liposomal formulation (lipo-RvD1) that targets and resolves the periodontitis associated inflammation and investigate its mechanism of action (MOA).
Methods: In vitro: Large multi-vesicular liposomes encapsulating RvD1 were prepared and characterized for RvD1 encapsulation efficiency (EE), release, and stability by ELISA.
Fluorescent-labeled liposomes were used to determine time-dependent biodistribution using IVIS system.
In vivo: The Ligature-induced periodontitis model was performed in C57BL/6 mice; To induce bacteria accumulation and bone loss, a silk 5-0 suture, was encircled around the 2nd upper molar’ CEJ. To prevent periodontitis development, local sub-gingival injection was applied with saline, free RvD1, empty liposomes, and lipo RvD1. Mice were sacrificed at day 1, 3, and 8 post-procedure. The distance between alveolar bone contour (ABC) and cementoenamel junction (CEJ) was measured by μCT. Gingival tissues were analyzed by H&E and TRAP staining and q-rtPCR (n=5-7/ group).
Results: Liposomes exhibited high RvD1 EE (>80%), demonstrated controlled release in vitro, and resided in periodontal tissue for 3d. Lipo-RvD1 restored bone better than free RvD1 at 8d. Lipo-RvD1 decreased osteoclasts and expression of catabolic markers (CTSK, MMP3) in days 3-8. Although free RvD1 decreased neutrophils and macrophages in days 1-3, lipo-RvD1 displayed a stronger inhibition effect of neutrophils and other inflammatory markers including, IL-6, IL-17 at 8d. Furthermore, lipo-RvD1 decreased Th17/Treg ratio and shifted T cells to the anti-inflammatory phase.
Conclusions: Lipo-RvD1 decreased bone loss significantly compared to free RvD1 and attenuated inflammatory processes. Our novel sustained-release formulation may be useful for other aggressive or chronic degenerative conditions in implantology, osteoarthritis and osteomyelitis.
Methods: In vitro: Large multi-vesicular liposomes encapsulating RvD1 were prepared and characterized for RvD1 encapsulation efficiency (EE), release, and stability by ELISA.
Fluorescent-labeled liposomes were used to determine time-dependent biodistribution using IVIS system.
In vivo: The Ligature-induced periodontitis model was performed in C57BL/6 mice; To induce bacteria accumulation and bone loss, a silk 5-0 suture, was encircled around the 2nd upper molar’ CEJ. To prevent periodontitis development, local sub-gingival injection was applied with saline, free RvD1, empty liposomes, and lipo RvD1. Mice were sacrificed at day 1, 3, and 8 post-procedure. The distance between alveolar bone contour (ABC) and cementoenamel junction (CEJ) was measured by μCT. Gingival tissues were analyzed by H&E and TRAP staining and q-rtPCR (n=5-7/ group).
Results: Liposomes exhibited high RvD1 EE (>80%), demonstrated controlled release in vitro, and resided in periodontal tissue for 3d. Lipo-RvD1 restored bone better than free RvD1 at 8d. Lipo-RvD1 decreased osteoclasts and expression of catabolic markers (CTSK, MMP3) in days 3-8. Although free RvD1 decreased neutrophils and macrophages in days 1-3, lipo-RvD1 displayed a stronger inhibition effect of neutrophils and other inflammatory markers including, IL-6, IL-17 at 8d. Furthermore, lipo-RvD1 decreased Th17/Treg ratio and shifted T cells to the anti-inflammatory phase.
Conclusions: Lipo-RvD1 decreased bone loss significantly compared to free RvD1 and attenuated inflammatory processes. Our novel sustained-release formulation may be useful for other aggressive or chronic degenerative conditions in implantology, osteoarthritis and osteomyelitis.