Study on Modified Collagen Matrix Loaded Human Periodontal Ligament Cells

Objective: To evaluate the effects of ionized collagen crosslinked with different crosslinking agents and analyze human periodontal ligament cells(hPDLCs) ingrowth and adhesive on the ionized collagen after crosslinked.

Methods: Three porous collagen matrices, Native collagen (NC), Methylation collagen with positive charge (MC) and Succinylated collagen with negative charge (SC), crosslinked by 1-ethyl-3-(3-dimethyl-aminopropyl) carbodiimide(EDC) were developed as scaffolds for periodontal tissue regeneration. Equilibrium swelling ratios of cross-linked collagen samples were measured by the weight method at some designed times (such as 0min,10min and 30min and so on). Using scanning electron microscopy (SEM) the mean diameters of pores and the pores ratio were examined, and the ingrowth of hPDLCs on collagen matrices was observed. Collagen matrices crosslinked by EDC was examined by collagenous enzymatic digestion in vitro, and was characterized contents of L-hydroxyproline in modified collagens combining infrared IR spectrum. Growth of hPDLCs on collagen matices was simultaneity researched using microscope and MTT assay.

Results: Data of equilibrium swelling ratios indicated that weight of collagen matrices had no obvious change in 20min. The contents of L-hydroxyproline of collagen matrices crosslinked by EDC were lower than uncrosslinked. Microscope and SEM research illuminated that the hPDLCs growth is good in NC and MC crosslinked by EDC, but no hPDLCs growth in SC with same crosslinked sample. MTT assay also showed that hPDLCs growed better in MC with EDC-crosslinked than that in NC crosslinked by EDC.

Conclusion: Collagen matrix crosslinked by EDC improves ability on modified collagens of NC and MC to resist collagenous enzyme. Since SC could be not crosslinked by EDC, SC was rapidly digested by collagenous enzyme in vitro. The reason hPDLCs growth better in MC with positive charge is that there is negative charge in hPDLCs surface, but no hPDLCs growth in SC with negative charge. Supported by NSFC grant 30640077.