The Biology of Facial Fillers

Abstract

The biologic behavior of a facial filler determines its advantages and disadvantages. The purpose of this article is to look at the relevant biology as part of a logical basis for making treatment decisions. Historical perspectives and biologic characteristics such as local tissue reaction (including phagocytosis and granulomatous inflammation) cross-linking, particle concentration, immunogenicity, biofilm formation, gel hardness, and collagen neogenesis are considered. Bovine collagen is the most immunogenic facial filler. Porcine and bioengineered human collagen implants have very low immunogenicity, but allergic reactions and elevations of IgG are possible. Cross-linking and concentration affect the longevity of collagen and hyaluronic acid fillers. Gel hardness affects how a hyaluronic acid filler flows through the syringe and needle. Calcium hydroxylapatite, poly-L-lactic acid, and polymethylmethacrylate fillers have been shown to stimulate collagen neogenesis. It appears that any facial filler can form a granuloma. Bacterial biofilms may play a role in the activation of quiescent granulomas. Various authors interpret the definition and significance of a granuloma differently.

Blood Aspiration Test for Cosmetic Fillers to Prevent Accidental Intravascular Injection in the Face

“…The facial artery also anastomoses with the contralateral facial artery, septal and alar branches, dorsal nasal branch of the ophthalmic artery, and infraorbital branch of the internal maxillary artery. The facial artery ascends along the side of the nose, ending at the medial canthus, where it is named the angular artery (8,9,10). After supplying the lacrimal sac and orbicularis oculi, it ends by anastomosing with the dorsal nasal branch (11) of the ophthalmic artery.…”

“…Calcium hydroxyapatite is degraded by macrophages, and a giant cell reaction may occur. 10 These products may be sterilized and packaged with a specific needle or cannula for safe use (Table 1). However, these products have not been tested for blood aspiration.…”

Subdermal Minimal Surgery with Hyaluronic Acid as an Effective Treatment for Neck Wrinkles

“…Two specific properties make HA an effective and practical filler: its capacity for hydrophilic binding to many times its weight in water and the substantial cross-linkage that occurs in HA polysaccharide chains, which results in slow degradation times. 11,12 HA has also been used in subdermal surgical technologies as a bacterialderived, 2.5-mg/mL, cross-linked solution (10% non-cross-linked, 90% cross-linked), with butanediol diglycidyl ether. It is specially formulated for use in an Airgent device.…”

Complication après injection d’acide hyaluronique : présentation d’un cas

“…Dans certains cas, un biofilm pourrait se former autour de l'AH au moment de l'injection [30]. Les bactéries encapsulées seraient relativement quiescentes, mais elles pourraient se réactiver spontanément ou après un évènement local et entrainer une réaction inflammatoire ou infectieuse aiguë [5,31].…”