The Role of Marine Organic Extract in Bone Regeneration: A Pilot Study

Abstract

Novel biomaterials capable of accelerating the healing process of skeletal tissues are urgently needed in dentistry. The present in vivo study assessed the osteoconductive and osteoinductive properties of experimental biphasic bioceramics (HA-TCP) modified or not by a nacre extract (marine organic extract, MOE) in a sheep model. Fabrication of MOE involved mixing ground nacre (0.05 g, particle sizes < 0.1 mm) with glacial ethanoic acid (5 mL, pH 7) for 72 hours using external magnetic stirring (25°C). Nonreactive carriers (sterile polythene tubes; 3/animal, radius: 2.5 mm, length: 10.0 mm) pertaining to the control (empty) or experimental groups (HA-TCP or MOE-modified HA-TCP) were implanted intramuscularly into the abdominal segment of the torso in sheep (n = 8, age: 2 years, weight: 45 kg). Euthanization of animals was performed at 3 and 6 months after surgery. Tissues harvested were subjected to macroscopic and radiographic assessments. Specimens were then stained for histological analysis. Both control and experimental animals were capable of inducing the neoformation of fibrous connective tissue at both time points where superior amounts of tissue formation and mineralization were detected for experimental groups (unaltered (at 3 and 6 mos) and MOE-modified HA-TCP (at 3 mos)). Histological results, however, revealed that mature bone formation was only observed for specimens fabricated with MOE-modified HA-TCP in a time-dependent manner. The present study has successfully demonstrated the in vivo utility of experimental biphasic bioceramics modified by MOE in an ectopic grafting sheep model. Promising osteoconductive and osteoinductive properties must be further developed and confirmed by subsequent research.

Figure 1

Macroscopic aspect (a, e), radiographic sections (b, f), and histological sections (c, d, g, h) with negative control or sham (tube without biomaterial). Microscopic appearance (HE, original 200x) demonstrating neovascularization (nv) and connective tissue fibers (cf).

Figure 2

Macroscopic aspect (a, e, i, m), radiographic sections (b, f, j, n), and histological sections (c, d, g, h, k, l, o, p) with HA-TCP® with and without marine organic extract. Microscopic appearance (HE, original 200x) demonstrating particle (p) of HA-TCP, osteoid (∗), neovascularization (nv), connective tissue fibers (cf), mature bone (mb), osteoclast (oc), osteoblast (ob), endosteal (ed). MOE  marine organic extract.