Combining Nonadhesive Materials into Microstructured Composite Surfaces Induces Cell Adhesion and Spreading

Enhancing adhesion and alignment of human gingival fibroblasts on dental implants

BACKGROUND

Promoting the directional attachment of gingiva to the dental implant leads to the formation of tight connective tissue which acts as a seal against the penetration of oral bacteria. Such a directional growth is mostly governed by the surface texture.

MATERIAL AND METHODS

In this study, three different methods, mechanical structuring, chemical etching and laser treatment, have been explored for their applicability in promoting cellular attachment and alignment of human primary gingival fibroblasts (HGFIBs).

RESULTS

The effectiveness of mechanical structuring was shown as a simple and a cost-effective method to create patterns to align HGIFIBs.

CONCLUSION

Combining mechanical structuring with chemical etching enhanced both cellular attachment and the cellular alignment.

Effect of Functional Groups of Self-Assembled Monolayers on Protein Adsorption and Initial Cell Adhesion

Surface modification plays a vital role in regulating protein adsorption and subsequently cell adhesion. In the present work, we prepared nanoscaled modified surfaces using silanization and characterized them using Fourier-transform infrared spectroscopy (FTIR), water contact angle (WCA), and atomic force microscopy (AFM). Five different (amine, octyl, mixed, hybrid, and COOH) surfaces were prepared based on their functionality and varying wettability and their effect on protein adsorption and initial cell adhesion was investigated. AFM analysis revealed nanoscale roughness on all modified surfaces. Fetal bovine serum (FBS) was used for protein adsorption experiment and effect of FBS was analyzed on initial cell adhesion kinetics (up to 6 h) under three different experimental conditions: (a) with FBS in media, (b) with preadsorbed FBS on surfaces, and (c) incomplete media, i.e., without FBS. Various cell features such as cell morphology/circularity, cell area and nuclei size were also studied for the above stated conditions at different time intervals. The cell adhesion rate as well as cell spread area were highest in the case of surfaces with preadsorbed FBS. We observed higher surface coverage rate by adhering cells on hybrid (rate, 0.073 h^-1) and amine (0.072 h^-1) surfaces followed by COOH (0.062 h^-1) and other surfaces under preadsorbed FBS condition. Surface treated with cells in incomplete media exhibited least adhesion rate, poor cell spreading and improper morphology. Furthermore, we found that initial cell adhesion rate and Δadhered cells (%) linearly increased with the change in α-helix content of adsorbed FBS on surfaces. Among all the modified surfaces and under all three experimental conditions, hybrid surface exhibited excellent properties for supporting cell adhesion and growth and hence can be potentially used as surface modifiers in biomedical applications to design biocompatible surfaces.

Phosphoprotein/chitosan electrospun nanofibrous scaffold for biomineralization

In this study, negatively charged phosvitin (PV) and positively charged chitosan (CS) were alternately deposited on negatively charged cellulose mats via layer-by-layer (LBL) self-assembly technique. Morphologies of the LBL films coating mats were observed by scanning electron microscope (SEM). Afterwards, in vitro biomimetic mineralization was carried out through incubation of the fibrous mats in a simulated body fluid (SBF) solution for different time. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used to characterize the morphology and structure of the deposited mineral phase on the scaffolds. In addition, the cell culture experiment demonstrated that the scaffolds with the LBL structured films were of good cell compatibility for MC3T3-E1 cells. Moreover, the cell proliferation was affected by the number of deposition layers and the composition of outer-most layer. Confocal laser scanning microscopy (CLSM) and SEM imaging revealed a good performance of cell adhesion and spreading of MC3T3-E1 cells on the surface of biocomposite scaffold. So CS/PV nanofibrous mats were satisfactory for the composite to be used in bioapplications.