Biphasic bone substitutes coated with PLGA incorporating therapeutic ions Sr2+ and Mg2+: cytotoxicity cascade and in vivo response of immune and bone regeneration.

The incorporation of bioactive ions into biomaterials has gained significant attention as a strategy to enhance bone tissue regeneration on the molecular level. However, little knowledge exists about the effects of the addition of these ions on the immune response and especially on the most important cellular regulators, the macrophages. Thus, this study aimed to investigate the in vitro cytocompatibility and in vivo regulation of bone remodeling and material-related immune responses of a biphasic bone substitute (BBS) coated with metal ions (Sr2+/Mg2+) and PLGA, using the pure BBS as control group. Initially, two cytocompatible modified material variants were identified according to the in vitro results obtained following the DIN EN ISO 10993-5 protocol. The surface structure and ion release of both materials were characterized using SEM-EDX and ICP-OES. The materials were then implanted into Wistar rats for 10, 30, and 90 days using a cranial defect model. Histopathological and histomorphometrical analyses were applied to evaluate material degradation, bone regeneration, osteoconductivity, and immune response. The findings revealed that in all study groups comparable new bone formation were found. However, during the early implantation period, the BBS_Sr2+ group exhibited significantly faster regeneration compared to the other two groups. Additionally, all materials induced comparable tissue and immune responses involving high numbers of both pro-inflammatory macrophages and multinucleated giant cells (MNGCs). In conclusion, this study delved into the repercussions of therapeutic ion doping on bone regeneration patterns and inflammatory responses, offering insights for the advancement of a new generation of biphasic calcium phosphate materials with potential clinical applicability.

Evaluation of plant-derived biomaterials for the development of tissue-engineered corneal substitutes.

Corneal blindness affects over 10 million patients worldwide. Due to the limited supply of donor corneas and frequent graft failure, bioengineered alternatives are crucial. To overcome drawbacks associated with corneal substitutes from synthetic biomaterials, fabrication from plant-derived biomaterials is a potential alternative. Herein, soy protein and glutenin in combination with different crosslinkers were evaluated for fabrication of corneal substitutes. Optical, mechanical, and biochemical properties of fabricated constructs and control rabbit corneas were evaluated in vitro. Soy protein crosslinked with peroxidase/H202 possessed transparency and mechanical properties comparable to controls, although their water content and biocompatibility were inferior. In contrast, soy protein crosslinked with tannic acid showed similar water content, tensile strength, and biocompatibility as rabbit corneas; however, these constructs displayed significantly lower transparency and higher strain to failure. Finally, glutenin cross-linked using formaldehyde showed excellent transparency, strain to failure, and biocompatibility, however; they exhibited significantly lower water content and tensile strength than controls. This study is the first to establish CIELAB color values for the rabbit cornea, allowing quantitative optical evaluation of tissue-engineered substitutes. Thus, a crosslinking strategy utilizing plant-derived proteins for fabrication of constructs with properties comparable to rabbit corneas is a promising direction for development of tissue-engineered corneal substitutes.

Effects of Edible Insect Powders as Meat Partial Substitute on Physicochemical Properties and Storage Stability of Pork Patties.

In this study, physicochemical and antioxidant properties, and storage stability (1, 3, and 7 days) of pork patties added with edible insect powders (EIP) of four species (Larvae of Tenenbrio molitor, Protaetia brevitarsis seulensis, Allomyrina dichotoma, and Gryllus bimaculatus) as meat partial substitutes were investigated. Twenty percent of each EIP was added to pork patties, and four treatments were prepared. On the other hand, two control groups were set, one with 0.1 g of ascorbic acid and the other without anything. Adding EIP decreased water content but increased protein, fat, carbohydrate, and ash contents. In addition, the use of EIP increased the water holding capacity and texture properties as well as decreased the cooking loss. However, the sensory evaluation and storage stability were negatively affected by the addition of EIP. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity had a positive effect on storage stability. It is believed that the addition of EIP resulted in high antioxidants due to the presence of polyphenol compounds in EIP. These results indicate that EIP has great potential to be used as meat partial substitute to improve the quality improvement and antioxidant in pork patties. However, in order to improve storage stability and consumer preference, further research is needed to apply it to patties by reducing the amount of EIP or adding auxiliary ingredients.

TPMS Microarchitectures for Vertical Bone Augmentation and Osteoconduction: An In Vivo Study.

Triply periodic minimal surface microarchitectures (TPMS) were developed by mathematicians and evolved in all kingdoms of living organisms. Renowned for their lightweight yet robust attributes, TPMS structures find application in diverse fields, such as the construction of satellites, aircrafts, and electric vehicles. Moreover, these microarchitectures, despite their intricate geometric patterns, demonstrate potential for application as bone substitutes, despite the inherent gothic style of natural bone microarchitecture. Here, we produced three TPMS microarchitectures, D-diamond, G-gyroid, and P-primitive, by 3D printing from hydroxyapatite. We explored their mechanical characterization and, further, implanted them to study their bone augmentation and osteoconduction potential. In terms of strength, the D-diamond and G-gyroid performed significantly better than the P-primitive. In a calvarial defect model and a calvarial bone augmentation model, where osteoconduction is determined as the extent of bony bridging of the defect and bone augmentation as the maximal vertical bone ingrowth, the G-gyroid performed significantly better than the P-primitive. No significant difference in performance was observed between the G-gyroid and D-diamond. Since, in real life, the treatment of bone deficiencies in patients comprises elements of defect bridging and bone augmentation, ceramic scaffolds with D-diamond and G-gyroid microarchitectures appear as the best choice for a TPMS-based scaffold in bone tissue engineering.

The substitute ENSO 16 has low impact on glucose metabolism in healthy humans: a randomized, double-blind, active-controlled, cross-over trial.

High sugar consumption is associated with cardiovascular diseases and diabetes. Current sugar substitutes may cause taste sensations and gastrointestinal symptoms. ENSO 16 is a combination of 16 different sugar substitutes and plant fibers and has been designed as a sugar alternative. The impact on plasma glucose metabolism as well as on gastrointestinal tolerance has not been investigated yet. 17 healthy participants were enrolled in this randomized, double-blind trial. Participants received a single oral dose of 30 g glucose or 30 g ENSO 16 and crossed over to the alternate treatment after a 7 day wash out period. The study endpoint was the effect on plasma glucose, insulin, C-peptide concentrations and gastrointestinal disorders. A questionnaire regarding gastrointestinal symptoms was used for individual subjective scoring. The mean baseline adjusted plasma glucose AUC0-180 min was significantly greater after glucose administration compared to ENSO 16 (n = 15, p = 0.0128, paired t-test). Maximum plasma glucose elevation over baseline was 117 mg*dl-1 and 20 mg*dl-1 after oral glucose or ENSO 16, respectively. Insulin and C-peptide AUC0-180 min were significantly greater after glucose compared to ENSO 16 intake (p < 0.01, Wilcoxon rank sum test). The mean maximal concentrations of plasma glucose, insulin and C-peptide after glucose intake were 1.5, 4.6 and 2.7-fold greater after glucose intake compared to ENSO 16 intake, respectively. Adverse reactions were mostly mild and not different between treatments. Conclusion. ENSO 16 has only a small impact on plasma glucose metabolism. This may be of interest in a dietary context and may help to reduce calory intake.Trail registration NCT05457400. First registration: 14/07/2022. https://clinicaltrials.gov/study/NCT05457400 .

Fabrication and histological evaluation of a self-setting granular cement using calcium sulfate hemihydrate granules with different pore distribution.

Granular type of bone substitutes is currently used in the field of dentistry to restore alveolar bone defects. However, the migration of the granules from the implantation site is still an unresolved issue. In this study, the feasibility to fabricate self-setting calcium sulfate hemihydrate (CSH) granules using different ranges of loading pressure: CSH(0), CSH(50), CSH(100), and CSH(150) was investigated with the hypothesis that CSH granules with reduced microporosity can inhibit the rapid dissolution rate of the calcium sulfate dihydrate (CSD) set blocks and induce bone regeneration. After 4 weeks of implantation, the granules were mostly replaced with new bone although no significant differences were observed. Nevertheless, the granules demonstrated the ability to set within the bone defect. It is therefore concluded that the setting ability of calcium sulfate can contribute to address the issue of migration of the granules and provide a useful guide for designing setting bone substitutes.

Integrative Analysis of the Microbiome and Metabolome of Broiler Intestine: Insights into the Mechanisms of Probiotic Action as an Antibiotic Substitute.

Antibiotic substitutes have become a research focus due to restrictions on antibiotic usage. Among the antibiotic substitutes on the market, probiotics have been extensively researched and used. However, the mechanism by which probiotics replace antibiotics remains unclear. In this study, we aimed to investigate this mechanism by comparing the effects of probiotics and antibiotics on broiler growth performance and intestinal microbiota composition. Results shown that both probiotics and antibiotics increased daily weight gain and reduced feed conversion rate in broilers. Analysis of ileum and cecum microorganisms via 16S rRNA gene sequencing revealed that both interventions decreased intestinal microbial diversity. Moreover, the abundance of Bacteroides increased in the mature ileum, while that of Erysipelatoclostridium decreased in the cecum in response to both probiotics and antibiotics. The main metabolites of probiotics and antibiotics in the intestine were found to be organic acids, amino acids, and sugars, which might play comparable roles in growth performance. Furthermore, disaccharides and trisaccharides may be essential components in the ileum that enable probiotics to replace antibiotics. These findings provide important insights into the mechanisms underlying the use of probiotics as antibiotic substitutes in broiler breeding.

The effect of a barrier membrane on the incorporation of deproteinized bovine bone mineral (DBBM) in experimental defects at the time of early implant placement. A preclinical study.

OBJECTIVES: This study aimed to assess membrane use with a bone substitute graft for guided bone regeneration (GBR) in experimental dehiscence defects. MATERIALS AND METHODS: Maxillary second incisors (I2) in 9 dogs were extracted. Six weeks later, implants were inserted and experimental dehiscence defects (5 × 3 mm) created on the buccal aspect. The defects and surrounding bone were grafted with deproteinized bovine bone mineral. One side (test) was covered with a resorbable collagen membrane whereas the contralateral side (control) was not. After 6 weeks, histomorphometrical analysis was performed to evaluate: (a) first bone-to-implant contact (fBIC), (b) buccal bone thickness at 1 mm increments from implant shoulder, (c) regenerated area (RA), (d) area and percentages of new bone (B), bone substitute (BS) and mineralized tissue (MT). RESULTS: The histological appearance was similar between test and control sites. At central and lateral sections, there were no differences between groups for fBIC, buccal bone thickness, RA, BS, B, %B, MT and %MT. At central sections, membrane use favoured more %BS and %MT (p = 0.052). There was significantly more B, %B and MT at lateral compared to central sections. CONCLUSIONS: Membrane use tended to retain more bone substitute, but had no effect on new bone ingrowth. Lateral sections showed significantly more bone ingrowth and mineralized tissue compared to central sections, confirming that new bone ingrowth takes place mainly from the lateral walls of the defect. CLINICAL RELEVANCE: Preclinical research to clarify the dynamics of bone regeneration in GBR procedures is relevant in clinical practice.

Hollow Defect-Rich Nanofibers as Sulfur Hosts for Lithium-Sulfur Batteries.

The slow redox kinetics of lithium-sulfur batteries severely limit their application, and sulfur utilization can be effectively enhanced by designing different cathode sulfur host materials. Herein, we report the hollow porous nanofiber LaNi0.6Co0.4O3 as a bidirectional host material for lithium-sulfur batteries. After Co is substituted into LaNiO3, oxygen vacancies are generated to enhance the material conductivity and enrich the active sites of the material, and the electrochemical reaction rate can be further accelerated by the synergistic catalytic ability of Ni and Co elements in the B-site of the active site of LaNi0.6Co0.4O3. As illustrated by the kinetic test results, LaNi0.6Co0.4O3 effectively accelerated the interconversion of lithium polysulfides, and the nucleation of Li2S and the dissolution rate of Li2S were significantly enhanced, indicating that LaNi0.6Co0.4O3 accelerated the redox kinetics of the lithium-sulfur battery during the charging and discharging process. In the electrochemical performance test, the initial discharge specific capacity of S/LaNi0.6Co0.4O3 was 1140.4 mAh g-1 at 0.1 C, and it was able to release a discharge specific capacity of 584.2 mAh g-1 at a rate of 5 C. It also showed excellent cycling ability in the long cycle test, with a single-cycle capacity degradation rate of only 0.08%. Even under the harsh conditions of high loaded sulfur and low electrolyte dosage, S/LaNi0.6Co0.4O3 still delivers excellent specific capacity and excellent cycling capability. Therefore, this study provides an idea for the future development of bidirectional high-activity electrocatalysts for lithium-sulfur batteries.

A Novel Dehydrated Human Umbilical Cord Particulate Medical Device: Matrix Characterization, Performance, and Biocompatibility for the Management of Acute and Chronic Wounds.

Chronic wounds present a significant socioeconomic burden forecasted to increase in prevalence and cost. Minimally manipulated human placental tissues have been increasingly employed and proven to be advantageous in the treatment of chronic wounds, showing improved clinical outcomes and cost-effectiveness. However, technological advances have been constrained by minimal manipulation and homologous use criteria. This study focuses on the characterization of a novel dehydrated human umbilical cord particulate (dHUCP) medical device, which offers a unique allogeneic technological advancement and the first human birth tissue device for wound management. Characterization analyses illustrated a complex extracellular matrix composition conserved in the dHUCP device compared to native umbilical cord, with abundant collagens and glycosaminoglycans imbibing an intricate porous scaffold. Dermal fibroblasts readily attached to the intact scaffold of the dHUCP device. Furthermore, the dHUCP device elicited a significant paracrine proliferative response in dermal fibroblasts, in contrast to fibrillar collagen, a prevalent wound device. Biocompatibility testing in a porcine full-thickness wound model showed resorption of the dHUCP device and normal granulation tissue maturation during healing. The dHUCP device is a promising advancement in wound management biomaterials, offering a unique combination of structural complexity adept for challenging wound topographies and a microenvironment supportive of tissue regeneration.

3D Bioprinting of Artificial Skin Substitute with Improved Mechanical Property and Regulated Cell Behavior through Integrating Patterned Nanofibrous Films.

Three-dimensional (3D) bioprinting has advantages for constructing artificial skin tissues in replicating the structures and functions of native skin. Although many studies have presented improved effect of printing skin substitutes in wound healing, using hydrogel inks to fabricate 3D bioprinting architectures with complicated structures, mimicking mechanical properties, and appropriate cellular environments is still challenging. Inspired by collagen nanofibers withstanding stress and regulating cell behavior, a patterned nanofibrous film was introduced to the printed hydrogel scaffold to fabricate a composite artificial skin substitute (CASS). The artificial dermis was printed using gelatin-hyaluronan hybrid hydrogels containing human dermal fibroblasts with gradient porosity and integrated with patterned nanofibrous films simultaneously, while the artificial epidermis was formed by seeding human keratinocytes upon the dermis. The collagen-mimicking nanofibrous film effectively improved the tensile strength and fracture resistance of the CASS, making it sewable for firm implantation into skin defects. Meanwhile, the patterned nanofibrous film also provided the biological cues to guide cell behavior. Consequently, CASS could effectively accelerate the regeneration of large-area skin defects in mouse and pig models by promoting re-epithelialization and collagen deposition. This research developed an effective strategy to prepare composite bioprinting architectures for enhancing mechanical property and regulating cell behavior, and CASS could be a promising skin substitute for treating large-area skin defects.

A comparative prospective study between the outcomes of one-stage Pelnac reconstruction and full thickness skin graft on donor site healing in the radial forearm and fibula flaps.

OBJECTIVES: Dermal substitutes are classically used in a 2-stage procedure followed by skin graft for wound healing. This study aims to evaluate the possibility to use an alternative technique for radial forearm and fibula donor sites coverage using one-stage Pelnac reconstruction. MATERIALS AND METHODS: 21 patients who underwent radial forearm and fibula flaps harvest for reconstruction of head and neck defects after oncological surgery were enroled in the study. 13 patients were treated by one-stage Pelnac reconstruction of the donor site defect, 8 patients underwent full thickness skin graft. The Vancouver Scar Scale was used to evaluate the scar quality. RESULTS: Most patients treated with one-stage Pelnac reconstruction showed good healing of the flap donor site, with minor complications, scar quality comparable to other treatment options and unimpaired function of the implicated limb. One patient had wound dehiscence at the radial forearm site, which was treated with secondary full thickness skin graft. In the group treated with FTSG we had three patients that developed complications, such as dehiscence of the graft and seroma. Overall, we reported comparable satisfaction with donor sites both for aesthetic and functional outcomes, in both groups of patients. CONCLUSION: The use of Pelnac without a following skin graft provides a viable method for the reconstruction of radial forearm and fibula flaps donor site. A longer postoperative care is needed, but the long-term aesthetic and functional results are satisfactory in comparison with full thickness skin graft.

Perceptions of three diets varying in animal- and plant-based protein contents: Analysis of participant experience diaries.

The market for new plant protein-based meat substitutes is expanding, although their consumption remains limited compared to animal-based protein sources. Further research is necessary to comprehend the perceptions of diets in which animal-based protein sources are partially replaced with plant proteins. This qualitative study is part of an intervention trial, during which participants adhered to one of the three intervention diets for 12 weeks: the ANIMAL diet (70% animal-based protein/30% plant-based protein), the 50/50 diet (50% animal/50% plant) or the PLANT diet (30% animal/70% plant). The dataset comprises 79 experience diaries from healthy participants aged 23 to 69. The study investigated perceptions of intervention diets, the meat protein (MPPs) and the plant protein products (PPPs) included in the intervention and self-reported changes in perceptions during the intervention period. These perceptions were categorized into eight themes: body-related experiences, practicalities and everyday life, sensory properties, social situations and special occasions, familiarity and novelty, health, ethical aspects, and non-specific liking. Across the diets, body-related experiences were the most frequently mentioned theme. The ANIMAL diet received more negative than positive comments. In contrast, comments on the 50/50 diet were relatively balanced between positive and negative, and the PLANT diet received more positive comments than negative ones. The PPPs were commented on in a positive way more often than the MPPs were. With consistent exposure, participants reported more positive than negative changes in perceptions. However, there is still room for improvement in enhancing the sensory quality and ease of food preparation of PPPs.

Does expanding wild venison consumption substitute livestock meat consumption? Evidence from the demand systems analysis of meat products in Hokkaido, Japan.

In many countries, growing deer populations cause environmental, economic, and traffic safety problems. This study sheds light on the potential implications of expanding the consumption of venison from hunted wild deer through deer population management efforts. It focuses on changes in environmental impacts resulting from changes in the demand for livestock meat due to increased consumption of wild venison. We analyzed the demand system between them using the Quadratic Almost Ideal Demand System (QUAIDS) model and scanner data from a grocery store chain in Hokkaido Prefecture, Japan. The results show that wild venison is a substitute good for pork and lamb. By contrast, wild venison is a complementary good for imported and domestic beef. Based on the estimated demand system model, we conducted an environmental footprint analysis to estimate the changes in environmental impacts when venison consumption increased. This shows that the greenhouse gas, water, and land footprints would increase, indicating greater environmental impacts, under a scenario of expanded venison consumption. The results demonstrate that increased venison consumption does not necessarily reduce the net environmental impacts of meat consumption, which depends on the demand system for meat products and the environmental footprint intensities of the respective products.

Pull-Out Strength of Orthodontic Miniscrews in the Temporal Bone.

BACKGROUND: Minimally invasive cochlear implant surgery by using a microstereotactic frame demands solid connection to the bone. We aimed to determine the stability of commercially available orthodontic miniscrews to evaluate their feasibility for frame's fixation. In addition, which substitute material most closely resembles the mechanical properties of the human temporal bone was evaluated. METHODS: Pull-out tests were carried out with five different types of orthodontic miniscrews in human temporal bone specimens. Furthermore, short fiber filled epoxy (SFFE), solid rigid polyurethane (SRPU50), bovine femur, and porcine iliac bone were evaluated as substitute materials. In total, 57 tests in human specimens and 180 tests in the substitute materials were performed. RESULTS: In human temporal bone, average pull-out forces ranged from 220 N to 285 N between screws. Joint stiffness in human temporal bone ranged between 14 N/mm and 358 N/mm. Statistically significant differences between the tested screws were measured in terms of stiffness and elastic energy. One screw type failed insertion due to tip breakage. No significant differences occurred between screws in maximum pull-out force. The average pull-out values of SFFE were 14.1 N higher compared to human specimen. CONCLUSION: Orthodontic miniscrews provided rigid fixation when partially inserted in human temporal bone, as evidenced by pull-out forces and joint stiffness. Average values exceeded requirements despite variations between screws. Differences in stiffness and elastic energy indicate screw-specific interface mechanics. With proper insertion, orthodontic miniscrews appear suitable for microstereotactic frame anchoring during minimally invasive cochlear implant surgery. However, testing under more complex loading is needed to better predict clinical performance. For further pull-out tests, the most suitable substitute material is SFFE.

κ-Carrageenan masking bitterness perception in surimi gels containing potassium chloride-based salt substitutes: Gel properties, oral processing, and sensory evaluation.

κ-Carrageenan (CG) was employed to mask the bitterness induced by 50% KCl in surimi gels to achieve salt reduction and gel performance improvement. The combination of KCl and CG (KCl + CG) yielded the increased textural characteristics and water-holding capacity (WHC) of surimi gels and facilitated the transition of free water to immobilized water. In addition, the KCl + CG supplement increased the turbidity and particle size of myofibrillar protein (MP) sols but decreased the surface hydrophobicity in a dose-dependent manner. The hydrophobic interactions and disulfide bonds played crucial roles in maintaining the stability of MP gels. The specific binding of potassium ions to the sulfate groups of CG limited the release and diffusion of potassium ions from the surimi gels during oral processing, effectively masking the bitterness perception and maintaining the saltiness perception. This study provides a promising strategy to reduce the utilization of sodium salt in surimi products.

Biphasic Calcium Phosphate in the Extraction Socket Preservation: A Systematic Review.

Introduction: Various studies have suggested use of socket grafting materials after dental extraction for socket preservation. However, there is no single material that has been accepted as standard for preserving the socket. The purpose of this systematic review was to analyze the evidence for the use of biphasic calcium phosphate for socket regeneration. Materials and Methods: The team conducted a systematic literature search in accordance with the protocol registered at PROSPERO. PubMed, OVID, and EMBASE databases were used in the search. The articles were then screened using RAYYAN open-source software for the synthesis of evidence. Results: Of the 240 articles found in the search, two studies could be included in the review. Conclusion: Biphasic calcium phosphate (60% hydroxyapatite, HA and 40% beta-tricalcium phosphate, ß-TCP) has a significant effect in the socket preservation and quality of bone regeneration.

Potential of gelatin hydrogel nonwoven fabrics (Genocel) as a skin substitute in a diabetic mouse skin defect model.

Background: Gelatin hydrogel nonwoven fabrics (Genocel) are three-dimensional gelatin scaffolds that provide cells with space for proliferation, migration, and differentiation. They are expected to be an effective wound healing modality to treat intractable wounds, such as diabetic foot ulcers, because they enhance early neovascularization when used as a skin substitute. In this study, we explored the healing process of Genocel applied to skin defects in diabetic mice and compared it with that of a conventional skin substitute, Pelnac. Methods: Genocel and Pelnac sheets were used to treat skin defects on the backs of diabetic mice. On days 7 and 14, the remaining wound area was evaluated and specimens were harvested for HE, Azan, anti-CD31, CD68, and CD163 staining to assess neoepithelialization, granulation tissue formation, capillary formation, and macrophage infiltration. Results: Wounds treated with Genocel showed a wound healing process comparable to that of wounds treated with Pelnac. No significant differences were observed in the remaining wound area, neoepithelial length, granulation formation, number of pan-macrophages, or M2 ratio on days 7 and 14. The only significant difference was the number of induced M2 macrophages, which was higher in Pelnac group than in the Genocel group on day 7 (p < 0.05). Conclusions: Genocel showed similar healing effects in diabetic wounds as Pelnac and is considered an effective wound management modality for diabetic ulcers.

A Wireless Battery-Free Implant With Optical Telemetry for In Vivo Cortical Stimulation.

We present a 100 µm-thick, wireless, and battery-free implant for brain stimulation through a U.S. Food and Drug Administration-approved collagen dura substitute without contact with the brain's surface, while providing visible-light spectrum telemetry to track the onset of stimulation. The device is fabricated on a 16 × 6.67 mm2 biocompatible parylene/PDMS substrate and is encapsulated with a 2 µm-thick transparent parylene layer that enables the relay of the LED brightness. The in vivo rodent testing confirmed the implant's ability to trigger motor response while generating observable brightness through the skin. The results reveal the prospect of wireless stimulation with enhanced safety by eliminating contact between the implant and the brain, with optical telemetry for facilitated tracking.

On the rheological and sensory properties of a novel natural salivary substitute.

The prevalence of xerostomia, the sensation of dry mouth, is estimated at 20 % in the general population and up to 50 % in older adults. Saliva plays different roles during bolus formation: lubrication, mixing, coating, hydration, dissolution, and comminution of food particles. This study proposes and tests artificial saliva formulations mimicking human saliva rheological and sensory perceptions. Shear and extensional rheology were assessed to select the type of formulation closest to saliva rheological characteristics. After evaluating three alternative sources, an extract simulating saliva rheology was produced from flax seeds. Friction coefficient and rheological properties, such as flow curves, relaxation times, and Trouton ratios, were compared favorably with human saliva. The sensory evaluation demonstrated that flaxseed extracts induce perceived mouth hydration, slipperiness, and adhesion exceeding that of human saliva. The flaxseed extract proposed in this can i) be used to study in vitro food oral processing and ii) pave the way to novel natural salivary substitutes to alleviate the symptoms of xerostomia.