• Sukuntha Phuaknapho D.D.S.
• Chantavat Sutthiboonyapan D.D.S., Cert. in Endodontics, M.S., Diplomate, Thai Board of Endodontics
• Somporn Swasdison D.D.S., Cert. in Pathology, Ph.D.

Objective To fabricate and characterize collagen scaffolds from porcine skin collagen mixed with
hydroxyapatite for using as scaffolds in guided bone regeneration.

Materials and methods The collagen used in this study was extracted from porcine skin by dissolving
in acid-enzyme mixture and salt precipitation. Three different concentrations (1.5% 2% and 2.5%
by weight) of the extracted collagen solutions were mixed with hydroxyapatite at the ratio of
hydroxyapatite : collagen = 1:10 (weight/volume). The collagen-hydroxyapatite mixtures were
fabricated to sponge-like scaffolds by 24-hour freeze drying method under 2 conditions, slow freezing
and fast freezing. The fabricated scaffolds were then cross-linked to increase their stability.
Ultrastructural characteristics of the scaffolds prepared by different conditions were studied using
scanning electron microscopy. Determination of the scaffold pore sizes was performed under the light
microscope and the data were statistically analyzed.

Results All collagen/hydroxyapatite scaffolds fabricated in this study were sponge-like, soft,
white, odorless and easily dissolved in water. Cross-linking of these scaffolds helped increasing their
stability. These scaffolds were porous under scanning electron microscopic observation. The walls of
the pores were made up of interconnecting sheaths of tightly packed collagen fibers with hydroxyapatite
crystals decorated at the surface. The pore sizes of scaffolds prepared from different collagen
concentrations were not statistically different (p > 0.05) while the pore sizes of the scaffolds prepared
under different freezing conditions were statistically different (p < 0.05). The scaffolds prepared under
slow freezing condition had larger pore sizes than those prepared under fast freezing condition.

Conclusion Porcine skin collagen mixed with hydroxyapatite can be fabricated to porous scaffold by
freeze drying and cross-linking techniques. The morphological characteristics and the pore sizes of
scaffolds were related to the rate of freezing condition but not to collagen concentration.

(CU Dent J. 2012;35:1-14)