Resistance to protein adsorption and adhesion of fibroblasts on nanocrystalline diamond films: the role of topography and boron doping.

Boron-doped nanocrystalline diamond (BNCD) films exhibit outstanding electrochemical properties that make them very attractive for the fabrication of electrodes for novel neural interfaces and prosthetics. In these devices, the physicochemical properties of the electrode materials are critical to ensure an efficient long-term performance. The aim of this study was to investigate the relative contribution of topography and doping to the biological performance of BNCD films. For this purpose, undoped and boron-doped NCD films were deposited on low roughness (LR) and high roughness (HR) substrates, which were studied in vitro by means of protein adsorption and fibroblast growth assays. Our results show that BNCD films significantly reduce the adsorption of serum proteins, mostly on the LR substrates. As compared to fibroblasts cultured on LR BNCD films, cells grown on the HR BNCD films showed significantly reduced adhesion and lower growth rates. The mean length of fibronectin fibrils deposited by the cells was significantly increased in the BNCD coated substrates, mainly in the LR surfaces. Overall, the largest influence on protein adsorption, cell adhesion, proliferation, and fibronectin deposition was due to the underlying sub-micron topography, with little or no influence of boron doping. In perspective, BNCD films displaying surface roughness in the submicron range may be used as a strategy to reduce the fibroblast growth on the surface of neural electrodes.

Women's HIV disclosure to the dentist: Does frequent contact matter?

OBJECTIVES: Research has shown inconsistent patterns of patients' HIV serostatus disclosure to their dentists. Common barriers to disclosure have included confidentiality concerns, fear of treatment refusal, and discrimination. This study evaluated the prevalence of HIV serostatus disclosure to the dentist, whether the frequency of dental care utilization is associated with disclosure, and reasons for nondisclosure among women living with HIV. METHODS: We administered a cross-sectional oral health survey to 1,526 women living with HIV in the Women's Interagency HIV Study including questions regarding HIV serostatus disclosure to dentists. Logistic regression models were used to analyze the association between dental care utilization (at least annually versus less than annually) and HIV serostatus disclosure to dentists. RESULTS: Overall, 83 percent of women reported that they disclosed their HIV serostatus to their dentist. The most common reasons for nondisclosure were: a) the dentist did not ask, b) believing that the dentist did not need to know, and c) not having a consistent dentist. In the multivariable logistic regression model, at least annual dental care utilization, compared to less than annual, led to a 59 percent reduction in the odds of HIV nondisclosure to the dentist. DISCUSSION: Study findings highlight that dentists who see their patients infrequently should consider methods for overcoming barriers to HIV nondisclosure and the possibility that their patient's HIV serostatus is undisclosed. Educating women living with HIV about how disclosure to dentists is a critical component of their dental assessment and treatment, and how preventive dental treatment can improve overall health outcomes, is important.

Oral health-related quality of life and unmet dental needs among women living with HIV.

BACKGROUND: Oral health-related quality of life (OHRQoL) is a multidimensional, perception-based measure of how oral health affects social and physical functioning and self-image. OHRQoL is important for assessing women living with HIV (WLWH) who may have unmet dental needs and experience disparities that impact dental care accessibility. METHODS: In 2016, the authors conducted an assessment of OHRQoL among a national sample of 1,526 WLWH in the Women's Interagency HIV Study using the Oral Health Impact Profile instrument, which assesses the frequency of 14 oral health impact items. OHRQoL was measured using multivariable linear regression with a negative binomial distribution to assess the association between report of a recent unmet dental need and OHRQoL. RESULTS: "Fair or poor" oral health condition was reported by 37.8% (n = 576) of WLWH. Multivariable linear regression showed that unmet dental needs had the strongest positive association with poor OHRQoL (difference in Oral Health Impact Profile mean, 2.675; P < .001) compared with not having unmet needs. The frequency of dental care utilization was not associated with higher OHRQoL. Older age, fair or poor dental condition, smoking, symptoms of anxiety and loneliness, and poor OHRQoL were also associated with worse OHRQoL. CONCLUSION: Self-perceived impact of oral health on social and physical function and self-image, as measured by OHRQoL, may be an easily assessable but underrecognized aspect of OHRQoL, particularly among women aging with HIV. PRACTICAL IMPLICATIONS: Dentists should implement OHRQoL assessments in their management of the care of patients with HIV to identify those who do have significant oral health impacts.

Dental insurance, dental care utilization, and perceived unmet dental needs in women living with HIV: Results from the Women's Interagency HIV Study.

OBJECTIVES: Dental care is the most commonly cited unmet health-care service due to cost. Previous research has highlighted the unmet dental needs of people living with HIV (PLWH). Understanding associations among dental insurance availability, dental care utilization, and the presence of unmet dental needs among PLWH is a public health priority. METHODS: Oral health surveys were collected cross-sectionally (April-October 2016) among 1,442 women living with HIV (WLWH) in the Women's Interagency HIV Study. Logistic regression models were used to analyze the association between having versus not having dental insurance by type (Ryan White, private, Medicaid/Medicare) and two primary outcomes: a) typical frequency of dental visits (at least annually, less than annually) and b) reporting an unmet dental need in the past 6 months. RESULTS: All dental insurance types were associated with higher odds of receiving annual dental care and, for those with either Medicare/Medicaid or private insurance, lower odds of having an unmet dental need. When WLWH were asked to describe their oral health, poor self-reported condition was associated with both an unmet dental need (odds ratio [OR]: 4.52, 95 percent Confidence Interval [CI] [3.29-6.20]) and lower odds of annual dental care utilization (OR: 0.44, 95 percent CI [0.34-0.57]). Self-reported depressive symptom burden was also linked to having an unmet dental need (OR: 2.10, 95 percent CI [1.46-3.01]). CONCLUSIONS: Dental insurance coverage increases dental care utilization and is associated with better oral health among WLWH. In the era of health-care reform, dental insurance coverage may be instrumental for enhancing treatment outcomes.

Suppression of anoikis by collagen coating of interconnected macroporous nanometric carbonated hydroxyapatite/agarose scaffolds.

Three dimensional interconnected macroporous (pore diameter: 600-800 µm) hydroxyapatite/agarose disks have been evaluated in this study as potential bone regeneration scaffolds. With this purpose, the adhesion and proliferation of human Saos-2 osteoblasts on this biomaterial were analyzed. As an index of cell function, the following parameters were measured: cell morphology, viability, cell size/complexity, cell cycle, reactive oxygen species (ROS) content, and lactate dehydrogenase (LDH) release. The existence of anoikis induced by inappropriate contacts between the cell and the scaffold has been detected by scanning electron microscopy, confocal microscopy, and flow cytometry. The intracellular nitric oxide content has been also measured as potential inducer of anoikis. The positive effects of previous scaffold coating with type I collagen on osteoblast adhesion as well as the collagen protection against anoikis have been demonstrated in this study.

Biocompatibility markers for the study of interactions between osteoblasts and composite biomaterials.

Biphasic calcium phosphate (BCP), a mixture of hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP), has attracted attention as an excellent bone graft substitute. Mixtures of ceramics with agarose, as natural biodegradable binder, have been recently performed in order to increase the flexibility of the ceramic component and to facilitate the biomaterial preparation. In previous studies we have evaluated the response of both L929 fibroblasts and Saos-2 osteoblasts to hydroxyapatite-betaTCP/agarose disks observing a higher sensitivity of osteoblasts to this biomaterial. In the present study, the use of specific fluorescent probes and antibodies has allowed to evaluate different cell function parameters as biocompatibility markers for the cell/biomaterial interaction of Saos-2 osteoblasts cultured for 7 days on hydroxyapatite-betaTCP/agarose disks. The cell cycle subG(1) fraction, the exposition of phosphatidylserine on the outside surface of the plasma membrane and the analysis of plasma membrane integrity versus cell size, indicate that the interaction with the biomaterial induces a light increase of apoptosis in osteoblasts without producing cell necrosis. The high percentage of viable cells on the biomaterial and the preservation of endothelial nitric oxide synthase (eNOS) expression, eNOS activity and mitochondrial membrane potential (Deltapsi(m)), demonstrate the good biocompatibility of hydroxyapatite-betaTCP/agarose disks and its potential utility for bone substitution and repair.

L929 fibroblast and Saos-2 osteoblast response to hydroxyapatite-betaTCP/agarose biomaterial.

Biphasic calcium phosphate, a mixture of hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP), has been successfully used as an excellent bone graft substitute because of the HA capacity for direct interaction with bone and the beta-TCP resorption properties. Agarose has been recently mixtured with ceramics as natural biodegradable binder to increase the biomaterial flexibility facilitating its placement into the bone defect. In this study, the behavior of L929 fibroblasts and Saos-2 osteoblasts cultured on hydroxyapatite-betaTCP/agarose disks has been evaluated. Both cell types adhere and proliferate on the biomaterial surface maintaining their characteristic morphology. Transitory changes on cell cycle, size, and complexity are observed. The biomaterial induces apoptosis in Saos-2 osteoblasts but not in fibroblasts. A transitory stimulation of fibroblast mitochondrial activity is observed. This effect remains in osteoblasts after 9 days of culture showing a higher sensitivity of this cell type. However, the intracellular reactive oxygen species content and the lactate dehydrogenase release of Saos-2 osteoblasts indicate that hydroxyapatite-betaTCP/agarose does not induce oxidative stress in this cell type and confirm the integrity of the osteoblast plasma membrane. These results underline the good biocompatibility of hydroxyapatite-betaTCP/agarose disks and its potential utility for bone substitution and repair.