A narrative overview of utilizing biomaterials to recapitulate the salient regenerative features of dental-derived mesenchymal stem cells / 国际口腔科学杂志·英文版

Tissue engineering approaches have emerged recently to circumvent many limitations associated with current clinical practices. This elegant approach utilizes a natural/synthetic biomaterial with optimized physiomechanical properties to serve as a vehicle for delivery of exogenous stem cells and bioactive factors or induce local recruitment of endogenous cells for in situ tissue regeneration. Inspired by the natural microenvironment, biomaterials could act as a biomimetic three-dimensional (3D) structure to help the cells establish their natural interactions. Such a strategy should not only employ a biocompatible biomaterial to induce new tissue formation but also benefit from an easily accessible and abundant source of stem cells with potent tissue regenerative potential. The human teeth and oral cavity harbor various populations of mesenchymal stem cells (MSCs) with self-renewing and multilineage differentiation capabilities. In the current review article, we seek to highlight recent progress and future opportunities in dental MSC-mediated therapeutic strategies for tissue regeneration using two possible approaches, cell transplantation and cell homing. Altogether, this paper develops a general picture of current innovative strategies to employ dental-derived MSCs combined with biomaterials and bioactive factors for regenerating the lost or defective tissues and offers information regarding the available scientific data and possible applications.

Effect of laser-dimpled titanium surfaces on attachment of epithelial-like cells and fibroblasts

PURPOSE: The objective of this study was to conduct an in vitro comparative evaluation of polished and laserdimpled titanium (Ti) surfaces to determine whether either surface has an advantage in promoting the attachment of epithelial-like cells and fibroblast to Ti. MATERIALS AND METHODS: Forty-eight coin-shaped samples of commercially pure, grade 4 Ti plates were used in this study. These discs were cleaned to a surface roughness (Ra: roughness centerline average) of 180 nm by polishing and were divided into three groups: SM (n=16) had no dimples and served as the control, SM15 (n=16) had 5-microm dimples at 10-microm intervals, and SM30 (n=16) had 5-microm dimples at 25-microm intervals in a 2 x 4 mm2 area at the center of the disc. Human gingival squamous cell carcinoma cells (YD-38) and human lung fibroblasts (MRC-5) were cultured and used in cell proliferation assays, adhesion assays, immunofluorescent staining of adhesion proteins, and morphological analysis by SEM. The data were analyzed statistically to determine the significance of differences. RESULTS: The adhesion strength of epithelial cells was higher on Ti surfaces with 5-microm laser dimples than on polished Ti surfaces, while the adhesion of fibroblasts was not significantly changed by laser treatment of implant surfaces. However, epithelial cells and fibroblasts around the laser dimples appeared larger and showed increased expression of adhesion proteins. CONCLUSION: These findings demonstrate that laser dimpling may contribute to improving the periimplant soft tissue barrier. This study provided helpful information for developing the transmucosal surface of the abutment.

Effect of laser-dimpled titanium surfaces on attachment of epithelial-like cells and fibroblasts

PURPOSE: The objective of this study was to conduct an in vitro comparative evaluation of polished and laserdimpled titanium (Ti) surfaces to determine whether either surface has an advantage in promoting the attachment of epithelial-like cells and fibroblast to Ti. MATERIALS AND METHODS: Forty-eight coin-shaped samples of commercially pure, grade 4 Ti plates were used in this study. These discs were cleaned to a surface roughness (Ra: roughness centerline average) of 180 nm by polishing and were divided into three groups: SM (n=16) had no dimples and served as the control, SM15 (n=16) had 5-microm dimples at 10-microm intervals, and SM30 (n=16) had 5-microm dimples at 25-microm intervals in a 2 x 4 mm2 area at the center of the disc. Human gingival squamous cell carcinoma cells (YD-38) and human lung fibroblasts (MRC-5) were cultured and used in cell proliferation assays, adhesion assays, immunofluorescent staining of adhesion proteins, and morphological analysis by SEM. The data were analyzed statistically to determine the significance of differences. RESULTS: The adhesion strength of epithelial cells was higher on Ti surfaces with 5-microm laser dimples than on polished Ti surfaces, while the adhesion of fibroblasts was not significantly changed by laser treatment of implant surfaces. However, epithelial cells and fibroblasts around the laser dimples appeared larger and showed increased expression of adhesion proteins. CONCLUSION: These findings demonstrate that laser dimpling may contribute to improving the periimplant soft tissue barrier. This study provided helpful information for developing the transmucosal surface of the abutment.

MicroRNAs: critical regulators of mRNA traffic and translational control with promising biotech and therapeutic applications

MicroRNAs [miRNAs] are a class of short, endogenously-initiated, non-coding RNAs that post-transcriptionally control gene expression via translational repression or mRNA turnover. MiRNAs have attracted much attention in recent years as they play critical roles in gene expression and are promising tools with many biotech and therapeutic applications. The molecular mechanisms underlying the translational control of mRNAs are not fully understood but emerging evidence point to a key role for microRNAs in this process. In this review, we discuss the potential role of miRNAs as regulators of mRNA traffic and translational control, focusing on molecular mechanisms of miRNA-mediated control of eukaryotic mRNA stability and translational efficiency. Translational control by miRNAs is often associated with silencing and repression of mRNAs via accumulation within cytoplasmic processing bodies [P-bodies], the site of mRNA storage and/or decay. Specific miRNAs can interact with the 3'UTR or 5'UTR of target mRNAs and regulate their stability as well as translational efficiency. A better understanding of these mechanisms is critical in advancing our knowledge of the role of these regulatory RNAs in modulating protein synthesis and controlling metabolic pathways in health and disease. The discovery of miRNAs and their important role in controlling many aspects of cell function and metabolism have led to considerable interest in biotech applications of miRNAs and their application in modulating specific gene expression. We thus highlight the growing biotech and therapeutic applications of miRNAs.