Icariin-Functionalized Nanodiamonds to Enhance Osteogenic Capacity In Vitro.

Somang Choi,Ji Seon Min,Han-Saem Jo,Sung Eun Kim,Hak-Jun Kim,Kyeongsoon Park,Sung Hyun Noh,Chae Ouk Lim

doi:10.3390/nano10102071

Abstract

Nanodiamonds (NDs) have been used as drug delivery vehicles due to their low toxicity and biocompatibility. Recently, it has been reported that NDs have also osteogenic differentiation capacity. However, their capacity using NDs alone is not enough. To significantly improve their osteogenic activity, we developed icariin (ICA)-functionalized NDs (ICA-NDs) and evaluated whether ICA-NDs enhance their in vitro osteogenic capacity. Unmodified NDs and ICA-NDs showed nanosized particles that were spherical in shape. The ICA-NDs achieved a prolonged ICA release for up to 4 weeks. The osteogenic capacities of NDs, ICA (10 μg)-NDs, and ICA (50 μg)-NDs were demonstrated by alkaline phosphatase (ALP) activity; calcium content; and mRNA gene levels of osteogenic-related markers, including ALP, runt-related transcript factor 2 (RUNX2), collagen type I alpha 1 (COL1A1), and osteopontin (OPN). In vitro cell studies revealed that ICA (50 μg)-ND-treated MC3T3-E1 cells greatly increased osteogenic markers, including ALP, calcium content, and mRNA gene levels of osteogenic-related markers, including ALP, RUNX2, COL1A1, and OPN compared to ICA (10 μg)-NDs or ND-treated cells. These our data suggest that ICA-NDs can promote osteogenic capacity.

Highlights

IntroductionBone tissues are composed of organic substances (i.e., collagen fibers) and inorganic components (i.e., hydroxyapatite ingredients) and they possess a high self-regenerative capacity as part of their healing response to fracture or injury
Bone tissues are composed of organic substances and inorganic components and they possess a high self-regenerative capacity as part of their healing response to fracture or injury
To develop the ICA-NDs, the surfaces of carboxylated NDs (cNDs) were modified with dopamine and coated with ICA

Summary

Introduction

Bone tissues are composed of organic substances (i.e., collagen fibers) and inorganic components (i.e., hydroxyapatite ingredients) and they possess a high self-regenerative capacity as part of their healing response to fracture or injury. Frozen bone and freeze-dried bone allografts have advantages, such as preservation of osteoinductive proteins, reduction of primary infection, and microbial contaminations [5,6,7]. Their use is severely hindered by limitations such as pain, limited supply, rejection, and disease transmission [8,9]. Xenogenic materials are mostly stable and biocompatible, and they have been used for treating various bone defects because they are similar or identical to the physicochemical properties of human bone [14] Several disadvantages, such as tissue reactions to xenografts and the complicated procedures regarding the removal of immunologically active cells and pathogens should be addressed [15]

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Conclusion