Exploring experiences of living with removable dentures-A scoping review of qualitative literature.

OBJECTIVE: Examine the literature on the experiences of living with removable dentures (complete or partial) to identify any gaps and provide a map for future research. BACKGROUND: Increasing proportions of society are living partially dentate with some form of restoration, including removable dentures. Previous studies have reported on the location, materials and usage of these prostheses, along with effects on oral-health-related quality of life (OHRQoL). However, less is known about experiences with removable dentures from a patient-centred perspective. METHODS: A scoping review of the qualitative literature was undertaken using the framework of Arksey and O'Malley, updated by Levac et al. Literature searches were carried out using Medline and Web of Science. Papers were screened by title and abstract using inclusion and exclusion criteria. Remaining papers were read in full and excluded if they did not meet the required criteria. Nine papers were included in the final review. FINDINGS: Key themes from these papers were: impact of tooth loss and living without teeth, and its impacts in relation to social position, appearance, confidence and function (chewing and speaking); social norms and tooth loss, including attitudes to tooth retention and treatment costs, and changes in intergenerational norms towards dentures; expectations of treatment, including patients being more involved in decision making, viewing the denture as a "gift" and dentures helping to achieve "an ideal"; living with a removable denture (complete or partial), including patient preparedness for a denture, adaptation and impacts on activities and participation; and the dentist-patient relationship, including issues with information and communication, and differing priorities between patients and dentists. CONCLUSION: Little qualitative research exists on experiences of living with a removable denture. Existing literature demonstrates the importance of dispersed activities in differing social, spatial and temporal contexts when wearing removable dentures. Focusing on processes of positive adaptation to dentures and OHRQoL, rather than deficits, is also required to fully understand patients' experiences. Additionally, more complex technological advances may not always be in the best interest of every patient.

Cationic Polymers Enable Internalization of Negatively Charged Chemical Probes into Bacteria.

The bacterial cell envelope provides a protective barrier that is challenging for small molecules and biomolecules to cross. Given the anionic nature of both Gram-positive and Gram-negative bacterial cell envelopes, negatively charged molecules are particularly difficult to deliver into these organisms. Many strategies have been employed to penetrate bacteria, ranging from reagents such as cell-penetrating peptides, enzymes, and metal-chelating compounds to physical perturbations. While cationic polymers are known antimicrobial agents, polymers that promote the permeabilization of bacterial cells without causing high levels of toxicity and cell lysis have not yet been described. Here, we investigate four polymers that display a cationic poly(2-(dimethylamino)ethyl methacrylate (D) block for the internalization of an anionic adenosine triphosphate (ATP)-based chemical probe into Escherichia coli and Bacillus subtilis. We evaluated two polymer architectures, linear and micellar, to determine how shape and hydrophobicity affect internalization efficiency. We found that, in addition to these reagents successfully promoting probe internalization, the probe-labeled cells were able to continue to grow and divide. The micellar structures in particular were highly effective for the delivery of the negatively charged chemical probe. Finally, we demonstrated that these cationic polymers could act as general permeabilization reagents, promoting the entry of other molecules, such as antibiotics.

Blended Block Polycation Micelles Enhance Antisense Oligonucleotide Delivery.

Nucleic acid-based medicines and vaccines are becoming an important part of our therapeutic toolbox. One key genetic medicine is antisense oligonucleotides (ASOs), which are short single-stranded nucleic acids that downregulate protein production by binding to mRNA. However, ASOs cannot enter the cell without a delivery vehicle. Diblock polymers containing cationic and hydrophobic blocks self-assemble into micelles that have shown improved delivery compared to linear nonmicelle variants. Yet synthetic and characterization bottlenecks have hindered rapid screening and optimization. In this study, we aim to develop a method to increase throughput and discovery of new micelle systems by mixing diblock polymers together to rapidly form new micelle formulations. We synthesized diblocks containing an n-butyl acrylate block chain extended with cationic moieties amino ethyl acrylamide (A), dimethyl amino ethyl acrylamide (D), or morpholino ethyl acrylamide (M). These diblocks were then self-assembled into homomicelles (A100, D100, and M100)), mixed micelles comprising 2 homomicelles (MixR%+R'%), and blended diblock micelles comprising 2 diblocks blended into one micelle (BldR%R'%) and tested for ASO delivery. Interestingly, we observed that mixing or blending M with A (BldA50M50 and MixA50+M50) did not improve transfection efficiency compared to A100; however, when M was mixed with D, there was a significant increase in transfection efficacy for the mixed micelle MixD50+M50 compared to D100. We further examined mixed and blended D systems at different ratios. We observed a large increase in transfection and minimal change in toxicity when M was mixed with D at a low percentage of D incorporation in mixed diblock micelles (i.e., BldD20M80) compared to D100 and MixD20+M80. To understand the cellular mechanisms that may result in these differences, we added proton pump inhibitor Bafilomycin-A1 (Baf-A1) to the transfection experiments. Formulations that contain D decreased in performance in the presence of Baf-A1, indicating that micelles with D rely on the proton sponge effect for endosomal escape more than micelles with A. This result supports our conclusion that M is able to modulate transfection of D, but not with A. This research shows that polymer blending in a manner similar to that of lipids can significantly boost transfection efficiency and is a facile way to increase throughput of testing, optimization, and successful formulation identification for polymeric nucleic acid delivery systems.

Enhanced ASO-Mediated Gene Silencing with Lipophilic pH-Responsive Micelles.

Herein, we examine the ASO-mediated gene silencing efficiency of pH-responsive micelles, by incorporating 2-(diisopropylamino)ethyl methacrylate (DIP) into the micelle core and comparing physical and biological properties with non-pH-responsive micelles. Additionally, the lipophilic effect of the micelle cores was examined in both types of micelles. Varying lipophilicity was achieved by varying alkyl monomer chain lengths─butyl (4), lauryl (12), and stearyl (18) methacrylate. Each of the micelles formed within our family offered the added benefit of well-defined and uniform templates for loading antisense oligonucleotide (ASO) payloads. Overall, the micelles followed previously established trends of outperforming their linear polymer (nonmicelle) analogs and ASO only control. More specifically, the highest performing micelles were the pH-responsive micelles with longer alkyl chains or higher lipophilicity─D-DIP+LMA and D-DIP+SMA (∼90% silencing). These two micelles demonstrated silencing efficiencies similar to Jet-PEI and Lipofectamine 2000 and caused lower toxicity than Lipofectamine 2000. The shortest alkyl chain pH-responsive micelle, D-DIP+BMA (64%), displayed strong gene silencing similar to that about that of its non-pH-responsive micelle, D-BMA (68%), and the pH-responsive micelle without an alkyl chain incorporated, D-DIP (59%). This work illuminates a minimum alkyl chain length dependence to allow gene silencing within our micelle family. However, including only longer alkyl chains into the micelle core without the pH-responsive unit DIP had a hindering effect, thus demonstrating the requirement of the DIP unit when including longer alkyl chain lengths. This work demonstrates the exemplary gene silencing efficiencies of polymeric micelles and uncovers the relationship between pH responsiveness and performance with lipophilic polymer micelles for enhancing ASO-mediated gene silencing.

Cationic Micelles Outperform Linear Polymers for Delivery of Antisense Oligonucleotides in Serum: An Exploration of Polymer Architecture, Cationic Moieties, and Cell Addition Order.

Antisense oligonucleotides (ASOs) are an important emerging therapeutic; however, they struggle to enter cells without a delivery vehicle, such as a cationic polymer. To understand the role of polymer architecture for ASO delivery, five linear polymers and five diblock polymers (capable of self-assembly into micelles) were synthesized with varying cationic groups. After complexation of each polymer/micelle with ASO, it was found that less bulky cationic moieties transfected the ASO more effectively. Interestingly, however the ASO internalization trend was the opposite of the transfection trend for cationic moiety, indicating internalization is not the major factor in determining transfection efficiency for this series. Micelleplexes (micelle-ASO complexes) generally enable higher transfection efficacy as compared to polyplexes (linear polymer-ASO complexes). Additionally, the order of addition of cells and complexes was explored. Linear polyplexes showed better transfection efficiency in adhered cells, whereas micelleplexes delivered the ASO more efficiently when the cells and micelleplexes were added simultaneously. This phenomenon may be due to increased cell-complex interactions as micelleplexes have increased colloidal stability compared to polyplexes. These findings emphasize the importance of polymer composition and architecture in governing the cellular interactions necessary for transfection, thus allowing advancement in the design principles for nonviral nucleic acid delivery formulations.

Polycation Architecture Affects Complexation and Delivery of Short Antisense Oligonucleotides: Micelleplexes Outperform Polyplexes.

Herein, we examine the complexation and biological delivery of a short single-stranded antisense oligonucleotide (ASO) payload with four polymer derivatives that form two architectural variants (polyplexes and micelleplexes): a homopolymer poly(2-dimethylaminoethyl methacrylate) (D), a diblock polymer poly(ethylene glycol)methylether methacrylate-block-poly(2-dimethylaminoethyl methacrylate) (ObD), and two micelle-forming variants, poly(2-dimethylaminoethyl methacrylate)-block-poly(n-butyl methacrylate) (DB) and poly(ethylene glycol)methylether methacrylate-block-poly(2-dimethylaminoethyl methacrylate)-block-poly(n-butyl methacrylate) (ObDB). Both polyplexes and micelleplexes complexed ASOs, and the incorporation of an Ob brush enhances colloidal stability. Micellplexes are templated by the size and shape of the unloaded micelle and that micelle-ASO complexation is not sensitive to formulation/mixing order, allowing ease, versatility, and reproducibility in packaging short oligonucleotides. The DB micelleplexes promoted the largest gene silencing, internalization, and tolerable toxicity while the ObDB micelleplexes displayed enhanced colloidal stability and highly efficient payload trafficking despite having lower cellular uptake. Overall, this work demonstrates that cationic micelles are superior delivery vehicles for ASOs denoting the importance of vehicle architecture in biological performance.

Cation Bulk and pKa Modulate Diblock Polymer Micelle Binding to pDNA.

Polymer-based gene delivery relies on the binding, protection, and final release of nucleic acid cargo using polycations. Engineering polymeric vectors, by exploring novel topologies and cationic moieties, is a promising avenue to improve their performance, which hinges on the development of simple synthetic methods that allow facile preparation. In this work, we focus on cationic micelles formed from block polymers, which are examined as promising gene compaction agents and carriers. In this study, we report the synthesis and assembly of six amphiphilic poly(n-butyl acrylate)-b-poly(cationic acrylamide) diblock polymers with different types of cationic groups ((dialkyl)amine, morpholine, or imidazole) in their hydrophilic corona. The polycations were obtained through the parallel postpolymerization modification of a poly(n-butyl acrylate)-b-poly(pentafluorophenyl acrylate) reactive scaffold, which granted diblock polymers with equivalent degrees of polymerization and subsequent quantitative functionalization with cations of different pKa. Ultrasound-assisted direct dissolution of the polycations in different aqueous buffers (pH = 1-7) afforded micellar structures with low size dispersities and hydrodynamic radii below 100 nm. The formation and properties of micelle-DNA complexes ("micelleplexes") were explored via DLS, zeta potential, and dye-exclusion assays revealing that binding is influenced by the cation type present in the micelle corona where bulkiness and pKa are the drivers of micelleplex formation. Combining parallel synthesis strategies with simple direct dissolution formulation opens opportunities to optimize and expand the range of micelle delivery vehicles available by facile tuning of the composition of the cationic micelle corona.

The potential of salivary biomarkers of nutritional status and dietary intake: A Systematic Review.

OBJECTIVES: To explore whether nutritional salivary biomarkers could be used to aid nutritional status assessment and/or support traditional dietary assessment methods for patients. DATA AND SOURCES: Searches were performed using four electronic databases; MEDLINE, EMBASE, Scopus and Web of Science. Trial registers (i.e. Cochrane), grey literature and reference lists were searched. STUDY SELECTION: Studies which measured nutritional salivary biomarkers related to nutritional status and/or dietary intake outcome were included. No restrictions on participants' age, study design, publication date, setting or health status. Animal studies, non-English language studies, commentaries, and conference abstracts were excluded. RESULTS: Study titles and abstracts were screened (n = 7982), full-texts assessed (n = 176) and 85 studies were included in a narrative synthesis. The most promising salivary biomarkers for nutritional status included: glucose, where saliva and serum levels were positively correlated in those with type 2 diabetes (T2D), higher salivary calcium levels in post-menopausal women in general and specifically those with lower bone mineral density (BMD), and salivary vitamin D to assess vitamin D status in healthy volunteers. Higher salivary total antioxidant capacity (TAC), nitrate/nitrite and fluoride were observed with increased antioxidant, nitrate/nitrite and fluoride dietary intake, respectively. A meta-analysis found significantly higher mean salivary glucose (n = 12) in T2D compared with healthy controls, but there was substantial heterogeneity (I2=94%) and evidence of publication bias. CONCLUSIONS: The most promising salivary biomarkers identified in this systematic review were, glucose, vitamin D, calcium, TAC, nitrate/nitrite and fluoride. However, this was based on a small number of studies of varying quality, with many lacking a salivary assay performance assessment. CLINICAL SIGNIFICANCE: At present, nutritional salivary biomarkers cannot be used alone to assess nutritional status or dietary intake. Further research into the most promising nutritional salivary biomarkers is required.

On a fundamental description of the Kovacs' kinetic signatures in glass-forming systems.

The time-evolution equation for the time-dependent static structure factor of the non-equilibrium self-consistent generalized Langevin equation (NE-SCGLE) theory was used to investigate the kinetics of glass-forming systems under isochoric conditions. The kinetics are studied within the framework of the fictive temperature (TF) of the glassy structure. We solve for the kinetics of TF(t) and the time-dependent structure factor and find that they are different but closely related by a function that depends only on temperature. Furthermore, we are able to solve for the evolution of TF(t) in a set of temperature-jump histories referred to as the Kovacs' signatures. We demonstrate that the NE-SCGLE theory reproduces all the Kovacs' signatures, namely, intrinsic isotherm, asymmetry of approach, and memory effect. In addition, we extend the theory into largely unexplored, deep glassy state, regions that are below the notionally "ideal" glass temperature.

Polymeric Delivery of Therapeutic Nucleic Acids.

The advent of genome editing has transformed the therapeutic landscape for several debilitating diseases, and the clinical outlook for gene therapeutics has never been more promising. The therapeutic potential of nucleic acids has been limited by a reliance on engineered viral vectors for delivery. Chemically defined polymers can remediate technological, regulatory, and clinical challenges associated with viral modes of gene delivery. Because of their scalability, versatility, and exquisite tunability, polymers are ideal biomaterial platforms for delivering nucleic acid payloads efficiently while minimizing immune response and cellular toxicity. While polymeric gene delivery has progressed significantly in the past four decades, clinical translation of polymeric vehicles faces several formidable challenges. The aim of our Account is to illustrate diverse concepts in designing polymeric vectors towards meeting therapeutic goals of in vivo and ex vivo gene therapy. Here, we highlight several classes of polymers employed in gene delivery and summarize the recent work on understanding the contributions of chemical and architectural design parameters. We touch upon characterization methods used to visualize and understand events transpiring at the interfaces between polymer, nucleic acids, and the physiological environment. We conclude that interdisciplinary approaches and methodologies motivated by fundamental questions are key to designing high-performing polymeric vehicles for gene therapy.

Effects of Hydrophobic Tail Length Variation on Surfactant-Mediated Protein Stabilization.

Recently, protein therapeutics have gained significant attention as a result of their enhanced selectivity and diminished side effects compared to traditional small-molecule drugs. Despite their advantages, protein formulations typically suffer from stability issues because of aggregation and denaturation during production and storage, often resulting in detrimental immune responses. Surfactants can be used to stabilize and protect proteins in solution by preventing protein adsorption onto interfaces or by forming protective structures in solution. Herein, a detailed structure-activity relationship study is described, demonstrating the role that hydrophobic tail length plays in surfactant-mediated stabilization of the model therapeutic protein IgG. The FM1000 series, originating from a surfactant scaffold that allows for easy structure modulation, was synthesized by a simple 2-step procedure. First, phenylalanine was acylated with a variety of acyl chlorides of differing lengths to yield n-acyl phenylalanine, which was then coupled to Jeffamine M1000, a polyethylene glycol-based amine, to yield the final surfactant. With this FM1000 series, it was observed that the 14 carbon-long tail surfactant (14FM1000) was optimal at preventing IgG aggregation compared to surfactants with tails that were longer or shorter. Using a combination of dynamic surface tensiometry and quartz crystal microbalance with dissipation, it was hypothesized that 14FM1000 was able to prevent IgG adsorption, and therefore aggregation, by adsorbing appreciably onto surfaces quickly. 14FM1000 had the fastest rate of initial adsorption compared to the other surfactants studied. Short-tail surfactants were slow to and did not adsorb appreciably onto surfaces, allowing IgG adsorption. Although long-tail surfactants were also slow to adsorb, allowing IgG to adsorb and aggregate, their equilibrium adsorption was strong. Additionally, 14FM1000 was the most reversibly adsorbed surfactant, likely improving its ability to desorb and adsorb quickly to transient surfaces, therefore protecting the IgG at each new hydrophobic surface and preventing aggregation. By understanding the structure-activity relationship between surfactants and protein stabilization, we move toward more efficient design of future surfactants increasing the stability and utility of important protein therapeutics.

Association between oral health status and future dietary intake and diet quality in older men: The PRIME study.

OBJECTIVES: This study investigated whether oral health status, defined as number of natural teeth and subsequent prosthodontic rehabilitation, was associated with future dietary intake and diet quality in older adults in The Prospective Epidemiological Study of Myocardial Infarction (PRIME). METHODS: PRIME was originally established to explore cardiovascular risk factors in 50-59 year old men in Northern Ireland (1991-1994). A rescreening phase assessed oral health (2001-2004), while diet was assessed in 2015. Diet quality was characterised by the Dietary Diversity Score and Mediterranean Diet Score. In the current analysis, associations between oral health status, dietary intake and quality were assessed using regression models in 1096 participants. RESULTS: Amongst study participants, the overall mean number of teeth was 18.5, 51.5 % had ≥21 natural teeth and 49.6 % wore dentures. Oral health status was categorised into five groups: 21-28 teeth with (n = 111) and without (n = 453) dentures, 1-20 teeth with (n = 354) and without (n = 99) dentures and edentate with dentures (n = 79). After full adjustment, men with ≥21 teeth and dentures had a higher future intake of fruit, vegetables, and nuts, and diet quality scores, compared to those with <21 teeth with dentures. Edentate men with dentures were less likely to achieve the future fruit dietary recommendation. CONCLUSIONS: Having ≥21 natural remaining teeth positively affected the future intake of fruit, vegetables, and nuts, as well as diet quality. Dentures may be beneficial in men with ≥21 natural remaining teeth, as they were associated with an increased future intake of fruit, vegetables, and nuts and better diet quality. CLINICAL SIGNIFICANCE: Oral health status is associated with dietary intake, after an average time period of 13 years, with those with a larger number of natural teeth having a better diet quality. Further research is required to investigate this relationship in larger, diverse populations with more detailed dietary assessment.

An RCT of atraumatic restorative treatment for older adults: 5 year results.

OBJECTIVES: to compare the survival of ART and a conventional restorative technique (CT) for restoring carious lesions in older adults after 5 years. METHODS: In this parallel randomised controlled clinical trial, 219 independently-living adults were recruited from a dental hospital/community and a geriatric day hospital. Ninety-nine patients who met the inclusion criteria and presented with carious lesions were randomly allocated to receive either ART or conventional restorations (anaesthesia, rotary instruments and resin-modified glass ionomer). The status of restorations was assessed 6 months, 1, 2 and 5 years after restoration placement. Estimates of cumulative survival were calculated for each interval between assessments and a Cox Proportional Hazards (PH) model was fitted to the interval-censored survival time. RESULTS: Three hundred restorations (ART n=142; CT n=158) were placed on 99 patients, 46 males and 53 females, with a mean age of 73.2, SD: 6.8 (65-90 yrs). After 5 years, ART and CT presented cumulative probability of survival of 85% and 79% (p=0.8095), respectively. CONCLUSIONS: ART presents survival rates comparable to a conventional technique, when treating older adults after 5 years. The ART approach could be a useful tool to provide dental care for older adults particularly in the nonclinical setting. (Trial Registration number: ISRCTN 76299321). CLINICAL RELEVANCE: This study shows that ART presents survival rates comparable to conventional techniques to treat carious lesions in older patients after 5 years. It is well accepted by this age cohort, and therefore could be an alternative to treat the elderly, especially those who are homebound or cannot attend the dentist.

First live birth after uterus transplantation in the United States.

Uterus transplantation has proven to be a successful treatment for women with absolute uterine infertility, caused either by the absence of a uterus or the presence of a nonfunctioning uterus. We report the first birth of a healthy child following uterus transplantation in the United States, from a recipient of a uterus allograft procured from an altruistic living donor. Two major modifications from the previously reported live births characterized this uterus transplant. First, the transplanted uterus relied upon and sustained the pregnancy while having only the utero-ovarian vein as venous outflow. The implication is a significantly simplified living donor surgery that paves the way for minimally invasive laparoscopic or robot-assisted techniques for the donor hysterectomy. Second, the time from transplantation to embryo transfer was significantly shortened from prior protocols, allowing for an overall shorter exposure to immunosuppression by the recipient and lowering the risk for potential adverse effects from these medications.

Live nondirected uterus donors: Psychological characteristics and motivation for donation.

Emerging research suggests that uterus transplantation is a viable option for women without a uterus who want to become pregnant and carry a child to term. Currently, no knowledge exists regarding nondirected uterus donors. This study (NCT 02656550) explored the baseline psychological characteristics of nondirected uterus donors at a single study site. Of the 62 potential donors who underwent initial screening, 6 nondirected donors were chosen and participated in uterus donation. Participants received a comprehensive evaluation, which included clinical history and psychological assessments. The mean age of the donors was 42 years; most (83%) were white/not Hispanic, and all had a college degree. Current depression was reported by 2 participants, past depression was reported in 2 participants, and past anxiety was reported in 3 participants. Based on several different psychological measures, donors had a higher general well-being than the normative sample, and none of the participants' scores indicated psychological distress. All 6 women indicated that giving another woman an opportunity to carry her own child was a motivation for pursuing uterus donation. Further research on potential psychological motives and gains for the donor as well as long-term effects on donors is crucial for ethical practice.

Deceased donor uterus retrieval: A novel technique and workflow.

Uterus transplantation has proven successful when performed with a living donor. Subsequently, interest in the novel field of reproductive transplantation is growing. The procedure is still considered experimental, with fewer than 25 cases performed worldwide, and the techniques of both uterus procurement and transplantation are still developing. We detail a new approach to deceased donor uterus procurement. In contrast to reported techniques and our own initial experience, in which the deceased donor uterus was procured post cross-clamp and after other organs were procured, our approach now is to perform the uterus procurement prior to the procurement of other organs in a multiorgan donor and hence prior to cross-clamp. We describe our practical experience in developing and implementing the logistical workflow for deceased donor uterus procurement in a deceased multiorgan donor setting.

A novel interferometric method for the study of the viscoelastic properties of ultra-thin polymer films determined from nanobubble inflation.

Glass formation and glassy behavior remain as the important areas of investigation in soft matter physics with many aspects which are still not completely understood, especially at the nanometer size-scale. In the present work, we show an extension of the "nanobubble inflation" method developed by O'Connell and McKenna [Rev. Sci. Instrum. 78, 013901 (2007)] which uses an interferometric method to measure the topography of a large array of 5 µm sized nanometer thick films subjected to constant inflation pressures during which the bubbles grow or creep with time. The interferometric method offers the possibility of making measurements on multiple bubbles at once as well as having the advantage over the AFM methods of O'Connell and McKenna of being a true non-contact method. Here we demonstrate the method using ultra-thin films of both poly(vinyl acetate) (PVAc) and polystyrene (PS) and discuss the capabilities of the method relative to the AFM method, its advantages and disadvantages. Furthermore we show that the results from experiments on PVAc are consistent with the prior work on PVAc, while high stress results with PS show signs of a new non-linear response regime that may be related to the plasticity of the ultra-thin film.