Collagen and fibronectin surface modification of nanoporous anodic alumina and macroporous silicon for endothelial cell cultures

BACKGROUND

The ability to direct the cellular response by means of biomaterial surface topography is important for biomedical applications. Substrate surface topography has been shown to be an effective cue for the regulation of cellular response. Here, the response of human aortic endothelial cells to nanoporous anodic alumina and macroporous silicon with collagen and fibronectin functionalization has been studied.

METHODS

Confocal microscopy and scanning electron microscopy were employed to analyse the effects of the material and the porosity on the adhesion, morphology, and proliferation of the cells. Cell spreading and filopodia formation on macro- and nanoporous material was characterized by atomic force microscopy. We have also studied the influence of the protein on the adhesion.

RESULTS

It was obtained the best results when the material is functionalized with fibronectin, regarding cells adhesion, morphology, and proliferation.

CONCLUSION

These results permit to obtain chemical modified 3D structures for several biotechnology applications such as tissue engineering, organ-on-chip or regenerative medicine.

Nanoporous Anodic Alumina Surface Modification by Electrostatic, Covalent, and Immune Complexation Binding Investigated by Capillary Filling

The fluid imbibition-coupled laser interferometry (FICLI) technique has been applied to detect and quantify surface changes and pore dimension variations in nanoporous anodic alumina (NAA) structures. FICLI is a noninvasive optical technique that permits the determination of the NAA average pore radius with high accuracy. In this work, the technique is applied after each step of different surface modification paths of the NAA pores: (i) electrostatic immobilization of bovine serum albumin (BSA), (ii) covalent attachment of streptavidin via (3-aminipropyl)-triethoxysilane and glutaraldehyde grafting, and (iii) immune complexation. Results show that BSA attachment can be detected as a reduction in estimated radius from FICLI with high accuracy and reproducibility. In the case of the covalent attachment of streptavidin, FICLI is able to recognize a multilayer formation of the silane and the protein. For immune complexation, the technique is able to detect different antibody-antigen bindings and distinguish different dynamics among different immune species.

Tailoring tobacco counseling to the competing demands in the clinical encounter

OBJECTIVES

We identified patterns of tobacco cessation counseling in primary care practices, including contextual factors that influence its provision.

STUDY DESIGN

A cross-sectional study was performed using direct observation of outpatient visits.

POPULATION

We included 91 outpatient visits by cigarette smokers visiting 20 family physicians in 7 Nebraska community family practices.

OUTCOMES MEASURED

We measured patterns and quality of tobacco counseling assessed by direct observation.

RESULTS

A hierarchy of 5 patterns was discernable, ranging from appropriate to inappropriate provision or nonprovision of tobacco cessation counseling.

CONCLUSIONS

Since tobacco-specific discussions are appropriate only in approximately three fourths of primary care visits by smokers, clinical practice guidelines that recommend intervention at every visit are unrealistic. However, the finding that only one third of eligible visits addressed tobacco makes it imperative that tobacco cessation counseling be reliably integrated into visits for well care and tobacco-related illnesses that represent teachable moments.

New community residents' preferences for dental service information

New residents of a community who wish to select a dentist need information about the dental services that are available. Dentists who wish to expand their practices may want to stimulate the flow of information that new residents consider important but are unable to find. A survey of 679 new residents of a metropolitan area disclosed that the greatest need appears to be for information that relates to quality of work, concern for patients, personal appearance, price, location, waiting time, and insurance form preparation.