Potential role of dental pulp stem cells conditioned medium for odontoblastic differentiation.

BACKGROUND: Functional bioengineered tooth regeneration using autologous or allogeneic alternative differentiated cells sources are thought to have a great potential in replacing conventional dentures. This study investigated the potential of dental pulp stem cells (DPSCs) conditioned medium for odontoblastic differentiation of Wharton's jelly mesenchymal stem cells (WJMSCs). The DPSCs derived from healthy adult permanent first molars were cultured at high confluence prior to conditioned medium collection. The WJMSCs were cultured in six different treatments, with varying ratios of culture media to DPSCs-conditioned medium. MTT assay was used to measure the rate of proliferation of WJMSCs, while immunocytochemistry staining was utilised to detect the expression of dental matrix protein 1 (DMP-1). The deposited calcium was detected and analysed via Alizarin-Red Staining (ARS). RESULTS: It was found that the proliferation of WJMSCs cultured under the mixture of complete medium and DPSCs conditioned medium showed significantly lower than the control; presumably the cells started to exit proliferative state prior differentiation. In 14 days of induction, the cells in all treatments showed osteoblastic-like morphology, calcium compound deposits were observed at day 7, 10 and 14 of differentiation suggested that DPSCs conditioned medium could lead to osteoblastic/odontoblastic differentiation. However, the DMP-1 protein can be seen only expressed minimally at day 14 of conditioned medium induction. CONCLUSIONS: In conclusion, DPSCs conditioned medium appeared as a potential odontoblastic induction approach for WJMSCs. To further investigate the stimulatory effects by DPSCs conditioned medium, specific signalling pathway need to be elucidated to enhance the differentiation efficiency.

Preliminary Study of In Vitro Three-Dimensional Skin Model Using an Ovine Collagen Type I Sponge Seeded with Co-Culture Skin Cells: Submerged versus Air-Liquid Interface Conditions.

Three-dimensional (3D) in vitro skin models have been widely used for cosmeceutical and pharmaceutical applications aiming to reduce animal use in experiment. This study investigate capability of ovine tendon collagen type I (OTC-I) sponge suitable platform for a 3D in vitro skin model using co-cultured skin cells (CC) containing human epidermal keratinocytes (HEK) and human dermal fibroblasts (HDF) under submerged (SM) and air-liquid interface (ALI) conditions. Briefly, the extracted OTC-I was freeze-dried and crosslinked with genipin (OTC-I_GNP) and carbodiimide (OTC-I_EDC). The gross appearance, physico-chemical characteristics, biocompatibility and growth profile of seeded skin cells were assessed. The light brown and white appearance for the OTC-I_GNP scaffold and other groups were observed, respectively. The OTC-I_GNP scaffold demonstrated the highest swelling ratio (~1885%) and water uptake (94.96 ± 0.14%). The Fourier transformation infrared demonstrated amide A, B and I, II and III which represent collagen type I. The microstructure of all fabricated sponges presented a similar surface roughness with the presence of visible collagen fibers and a heterogenous porous structure. The OTC-I_EDC scaffold was more toxic and showed the lowest cell attachment and proliferation as compared to other groups. The micrographic evaluation revealed that CC potentially formed the epidermal- and dermal-like layers in both SM and ALI that prominently observed with OTC-I_GNP compared to others. In conclusion, these results suggest that OTC_GNP could be used as a 3D in vitro skin model under ALI microenvironment.