Nickel-based perovskite-catalysed direct phenol-to-aniline liquid-phase transformations.

Liquid phase direct amination of phenols to primary anilines with hydrazine was achieved using commercial NiLa-perovskite catalysts as bifunctional Lewis acid/redox-active catalysts without adding any external hydride sources. The amination strategy took place efficiently in the absence of any amount of reducing gasses (H2/NH3) and noble metals under mild conditions.

Tirzepatide modulates the regulation of adipocyte nutrient metabolism through long-acting activation of the GIP receptor.

Tirzepatide, a glucose-dependent insulinotropic polypeptide/glucagon-like peptide 1 receptor (GIPR/GLP-1R) agonist, has, in clinical trials, demonstrated greater reductions in glucose, body weight, and triglyceride levels compared with selective GLP-1R agonists in people with type 2 diabetes (T2D). However, cellular mechanisms by which GIPR agonism may contribute to these improved efficacy outcomes have not been fully defined. Using human adipocyte and mouse models, we investigated how long-acting GIPR agonists regulate fasted and fed adipocyte functions. In functional assays, GIPR agonism enhanced insulin signaling, augmented glucose uptake, and increased the conversion of glucose to glycerol in a cooperative manner with insulin; however, in the absence of insulin, GIPR agonists increased lipolysis. In diet-induced obese mice treated with a long-acting GIPR agonist, circulating triglyceride levels were reduced during oral lipid challenge, and lipoprotein-derived fatty acid uptake into adipose tissue was increased. Our findings support a model for long-acting GIPR agonists to modulate both fasted and fed adipose tissue function differentially by cooperating with insulin to augment glucose and lipid clearance in the fed state while enhancing lipid release when insulin levels are reduced in the fasted state.

Prediabetes and poorly controlled type-2 diabetes as risk indicators for peri-implant diseases:A systematic review and meta-analysis.

OBJECTIVE: The study answers the PECO question: "In adults with dental implants (P), do subjects suffering from type-2 diabetes or prediabetes (E) have worse peri-implant conditions (O) than subjects without type-2 diabetes and prediabetes (C)?". Prediabetes (5.7-6.4 % HbA1c), and the different qualities of glycemic control in type-2 diabetes; well-controlled (>8 % HbA1c), and poorly controlled (>8 % HbA1c) individuals; were classified according to the recommendations of the American Diabetes Association. DATA: Predefined search keys were used with search terms including: Dental implant, diabetes mellitus, glycemic control and HbA1c. SOURCES: An electronic search in the MEDLINE, Embase, and Cochrane libraries were conducted without any filters or language restrictions. Additionally, manual search of the reference lists were carried out to identify all relevant articles. STUDY SELECTION: Eligibility criteria were cohort, case-control and cross-sectional studies that answerd our PECO question with at least 1 year of follow-up. From a total of 2660 records, 35 articles (1761 individuals) were included in the analysis. Meta-analytic difference in means for crestal bone loss was 1.2 mm [95 % CI=0.4; 2.1] in patients with prediabetes, 1.8 mm [CI=1.0; 2.7] in poorly controlled patients, whereas 0.4 mm [CI=-0.3; 1.1] in well-controlled individuals. Meta-regression showed that 1 % increase in HbA1c increased crestal bone loss by 0.24 mm. CONCLUSIONS: Within the limitations of the study, patients with poorly controlled type-2 diabetes or prediabetes may have worse peri-implant conditions compared to patients without diabetes and well-controlled type-2 diabetes. Well-controlled type-2 diabetes is not a risk indicator for peri-implant diseases. CLINICAL SIGNIFICANCE: Clinicians should measure blood HbA1c levels when planning implant-supported restorations, thus patients with undiagnosed or poorly controlled type-2 diabetes can be identified, that allows for glycemic level adjustment prior to dental implant surgery, ensuring peri-implant health. PROTOCOL REGISTRATION NUMBER: (CRD42022375263).

The Effect of Nicotine-Containing Products on Peri-Implant Tissues: A Systematic Review and Network Meta-Analysis.

INTRODUCTION: Smokers have a higher chance of developing peri-implant diseases and are therefore considered an at-risk population. Our aim was to compare peri-implant characteristics in users of electronic cigarettes (EC), waterpipes (WP), cigarettes (CS), smokeless tobacco (ST), and nonsmokers (nonusers of any nicotine and tobacco product; NS). AIMS AND METHODS: A systematic search of four electronic databases (PubMed, EMBASE, Web of Science, and CENTRAL) was performed until April 2023, restricted to English language. Thirty-nine observational studies were included in the qualitative synthesis, of which 32 studies were included in a Bayesian network meta-analysis. Using a predesigned form, two researchers independently collected data about marginal bone loss (MBL), probing pocket depth (PPD), plaque index, bleeding on probing, modified plaque index, probing pocket depth > 4 mm (PPD > 4), gingival index, peri-implant sulcular fluid volume, and TNF-α and IL-1ß levels. QUIPS and CINeMA were used to evaluate the risk of bias and certainty of evidence. RESULTS: Nonsmokers had the smallest MBL. Most nicotine-containing product users had significantly higher MBL (CS, mean difference [MD]: 1.34 credible interval [CrI]: 0.85, 1.79; WP, MD: 1.58 CrI: 0.84, 2.35; ST, MD: 2.53, CrI: 1.20, 3.87) than NS. Electronic cigarettes did not show significant difference compared to NS (MD: 0.52 CrI: -0.33, 1.36). In secondary outcomes, NS were ranked in first place. Subset analysis based on smoking habit, implant duration, and maintenance control revealed no differences in ranking probability. CONCLUSIONS: Most nicotine-containing product users presented worse peri-implant parameters compared to NS, while EC users did not show significant differences to NS in many outcomes. IMPLICATIONS: Alternative nicotine-containing products are gaining popularity and are often considered less harmful by the general public compared to traditional cigarettes. This is the first network meta-analysis comparing users of four nicotine-containing products and NS. This study shows that CS, WP, and ST have a detrimental effect on the overall health of peri-implant tissues. EC users also presented inferior parameters compared to NS; however, the difference was not significant in many outcomes. It is essential to educate patients who are using nicotine-containing products, and to provide proper maintenance and appropriate cessation support. Well-designed multiarmed studies are needed for direct comparison of different products, including heated tobacco products. Greater transparency of confounding factors is needed regarding smoking habit and oral hygiene.

Aromatase Inhibitors and Plasma Lipid Changes in Postmenopausal Women with Breast Cancer: A Systematic Review and Meta-Analysis.

Background: Women are typically diagnosed with estrogen receptor-positive breast cancer around the postmenopausal period when declining estrogen levels initiate changes in lipid profiles. Aromatase inhibitors (AI) are used to prevent the progression of cancer; however, a further reduction in estrogen levels may have detrimental effects on lipid levels, which was our working hypothesis. Methods: Our meta-analysis was conducted on the lipid profiles of postmenopausal breast cancer patients at baseline and at different treatment time points. Results: We identified 15 studies, including 1708 patients. Studies using anastrozole (ANA), exemestane (EXE), letrozole (LET), and tamoxifen (TMX) were involved. Subgroup analyses revealed that 3- and 12-month administrations of LET and EXE lead to negative changes in lipid profiles that tend to alter the lipid profile undesirably, unlike ANA and TMX. Conclusions: Our results suggest that, despite statistically significant results, EXE and LET may not be sufficient to cause severe dyslipidemia in patients without cardiovascular comorbidities according to the AHA/ACC Guideline on the Management of Blood Cholesterol. However, the results may raise the question of monitoring the effects of AIs in patients, especially those with pre-existing cardiovascular risk factors such as dyslipidemia.

Comparative analysis of surgical and prosthetic rehabilitation in maxillectomy: A systematic review and meta-analysis on quality-of-life scores and objective speech and masticatory measurements.

STATEMENT OF PROBLEM: Patients with oro-antral communication, whether from trauma, disease, or congenital anomalies, have options for surgical reconstruction or prosthetic obturation, but guiding interdisciplinary protocols are lacking. PURPOSE: The purpose of this systematic review and meta-analysis was to compare surgical reconstruction and prosthetic obturation, identifying correlations with baseline characteristics to determine the most effective approach for specific patients. MATERIAL AND METHODS: A systematic search was conducted in 4 databases. Searching, screening, data extraction, and risk of bias assessment were performed by 2 reviewers. Eligible studies focused on patients with palatomaxillary defects from cancer-related maxilla surgeries. Traumatic or congenital defects were excluded. The study compared prosthetic restoration (either with surgical or definitive obturators) to surgical reconstruction using flaps or grafts. Patients with surgical restoration after tooth extraction were excluded. Both subjective and objective outcomes were used for comparison. RESULTS: Thirteen articles were included in the qualitative synthesis and 9 in the meta-analysis. Patient scores on quality-of-life questionnaires, objective speech, and masticatory ability evaluations were compared. The number of patients who underwent surgical reconstruction was 206, whereas 260 patients received prosthetic obturators. Results showed no significant differences. In the "activity" domain of the University of Washington QoL questionnaire, however, the 1.92 (0.45, 3.40) score difference was not clinically relevant. However, the heterogeneity of trials, the transient nature of subjective evaluations, the low number of participants, and major confounding biases did not allow a solid conclusion to be drawn. CONCLUSIONS: The growing number of maxillectomy patients demands firm evidence on which rehabilitation to choose and when it should be done. The result suggests that obturator devices and surgical reconstruction have similar effects on quality of life and health outcomes. A multicentric registry in which patient strata could be analyzed separately by age, adjuvant therapies, defect sizes, and remaining dentition is advocated.

Advancing accuracy in guided implant placement: A comprehensive meta-analysis: Meta-Analysis evaluation of the accuracy of available implant placement Methods.

OBJECTIVES: This meta-analysis aimed to determine the accuracy of currently available computer-assisted implant surgery (CAIS) modalities under in vitro conditions and investigate whether these novel techniques can achieve clinically acceptable accuracy. DATA: In vitro studies comparing the postoperative implant position with the preoperative plan were included. Risk of bias was assessed using the Quality Assessment Tool For In Vitro Studies (QUIN Tool) and a sensitivity analysis was conducted using funnel plots. SOURCES: A systematic search was performed on April 18, 2023, using the following three databases: MEDLINE (via PubMed), EMBASE, and Cochrane Central Register of Controlled Trials. No filters or restrictions were applied during the search. RESULTS: A total of 5,894 studies were included following study selection. Robotic- and static CAIS (sCAIS) had the most accurate and clinically acceptable outcomes. sCAIS was further divided according to the guidance level. Among the sCAIS groups, fully guided implant placement had the greatest accuracy. Augmented reality-based CAIS (AR-based CAIS) had clinically acceptable results for all the outcomes except for apical global deviation. Dynamic CAIS (dCAIS) demonstrated clinically safe results, except for horizontal apical deviation. Freehand implant placement was associated with the greatest number of errors. CONCLUSIONS: Fully guided sCAIS demonstrated the most predictable outcomes, whereas freehand sCAIS demonstrated the lowest accuracy. AR-based and robotic CAIS may be promising alternatives. CLINICAL SIGNIFICANCE: To our knowledge, this is the first meta-analysis to evaluate the accuracy of robotic CAIS and investigate the accuracy of various CAIS modalities.

The use of autogenous tooth bone graft is an efficient method of alveolar ridge preservation - meta-analysis and systematic review.

BACKGROUND: Ridge resorption following tooth extraction may be reduced by alveolar ridge preservation (ARP). Previous randomized clinical trials and systematic reviews have suggested that autogenous tooth bone graft (ATB) can be an effective alternative material for ARP. However, the results are heterogeneous. Therefore, our research aimed to evaluate the efficacy of ATB in ARP. METHODS: A systematic search was conducted in Cochrane Library, Embase, MEDLINE and Scopus for studies published from inception to 31 November 2021. We searched searched for randomized, non-randomized controlled trials and case series reporting on ATB use for ARP. The primary outcome was the ridge width difference pre- and post-surgery, measured in millimetres (mm) measured on CBCT (cone beam computed tomography). The secondary outcomes were the histological results. We followed the PRISMA2020 recommendations for reporting our systematic review and meta-analysis. RESULTS: The analysis included eight studies for the primary and six for the secondary outcomes. The meta-analysis revealed a positive ridge preservation effect with a pooled mean difference ridge width change of -0.72 mm. The pooled mean residual graft proportion was 11.61%, and the newly formed bone proportion was 40.23%. The pooled mean of newly formed bone proportion was higher in the group where ATB originated from both the root and crown of the tooth. CONCLUSIONS: ATB is an effective particulate graft material in ARP. Complete demineralization of the ATB tends to decrease the proportion of newly formed bone. ATB can be an attractive option for ARP. TRIAL REGISTRATION: The study protocol was registered on PROSPERO (CRD42021287890).

The Wisdom in Teeth: Neuronal Differentiation of Dental Pulp Cells.

Mesenchymal stem/stromal cells (MSCs) are found in almost all postnatal organs. Under appropriate environmental cues, multipotency enables MSCs to serve as progenitors for several lineage-specific, differentiated cell types. In vitro expansion and differentiation of MSCs give the opportunity to obtain hardly available somatic cells, such as neurons. The neurogenic potential of MSCs makes them a promising, autologous source to restore damaged tissue and as such, they have received much attention in the field of regenerative medicine. Several stem cell pool candidates have been studied thus far, but only a few of them showed neurogenic differentiation potential. Due to their embryonic ontology, stem cells residing in the stroma of the dental pulp chamber are an exciting source for in vitro neural cell differentiation. In this study, we review the key properties of dental pulp stem cells (DPSCs), with a particular focus on their neurogenic potential. Moreover, we summarize the various presently available methods used for neural differentiation of human DPSCs also emphasizing the difficulties in reproducibly high production of such cells. We postulate that because DPSCs are stem cells with very close ontology to neurogenic lineages, they may serve as excellent targets for neuronal differentiation in vitro and even for direct reprogramming.

Characterization of Electrospun Polysuccinimide-Dopamine Conjugates and Effect on Cell Viability and Uptake.

Biocompatible nanofibrous systems made by electrospinning have been studied widely for pharmaceutical applications since they have a high specific surface and the capability to make the entrapped drug molecule amorphous, which increases bioavailability. By covalently conjugating drugs onto polymers, the degradation of the drug as well as the fast clearance from the circulation can be avoided. Although covalent polymer-drug conjugates have a lot of advantages, there is a lack of research focusing on their nano-formulation by electrospinning. In this study, polysuccinimide (PSI) based electrospun fibrous meshes conjugated with dopamine (DA) are prepared. Fiber diameter, mechanical properties, dissolution kinetics and membrane permeability are thoroughly investigated, as these are crucial for drug delivery and implantation. Dopamine release kinetics prove the prolonged release that influenced the viability and morphology of periodontal ligament stem cells (PDLSCs) and SH-SY5Y cells. The presence of dopamine receptors on both cell types is also demonstrated and the uptake of the conjugates is measured. According to flow cytometry analysis, the conjugates are internalized by both cell types, which is influenced by the chemical structure and physical properties. In conclusion, electrospinning of PSI-DA conjugates alters release kinetics, meanwhile, conjugated dopamine can play a key role in cellular uptake.

Molecular orientation rules the efficiency of immobilized antioxidants.

Tannic acid (TA) and glutathione (GSH) are important molecular antioxidants against reactive oxygen species. Their efficiency is limited by low solubility and high sensitivity, which may be solved by confinement in composite materials. Here, effect of immobilization of these antioxidants on their radical scavenging activity was investigated using layered double hydroxide (LDH) nanoparticles as hosts. Different preparation methods were applied to build composite systems leading to variations in the molecular orientation of both TA and GSH on the surface or among the layers of LDHs. Systematic combination of spectroscopy (FT-IR, Raman, UV-VIS-NIR-DRS), diffraction (XRD) and microscopy (SEM) methods revealed perpendicular or parallel orientation of TA on the surface of LDH depending on the preparation approach applied. Immobilization of GSH protected the antioxidant molecules from degradation. Radical scavenging tests evidenced that the activity of the antioxidants strongly depends on the molecular orientation. The LDH supported GSH and TA proved as durable and reusable antioxidant agents to be applied as radical scavengers in medical therapies or in industrial processes.

Results in Antireflux Surgery, an Analysis of Case-Controlled Cohorts versus Multicenter Studies and Meta-Analyses.

Introduction: With the advent of minimally invasive techniques, laparoscopic Nissen fundoplication and Toupet partial fundoplication have been very successful in the management of GERD. In the past 10 years, a number of very attractive new technologies have entered the market around therapeutic GERD-management such as Transoral Incisionless Gastroplication, other endoscopic plication techniques, and the implantation of the magnetic sphincter augmentation (MSA). These new technologies are excessively promoted by the respective companies, propagating their techniques as causing fewer side effects. The purpose of this paper is an overview on the successrates of these differently used techniques and technologies and, in addition, different study-designs. Methods: A literature review was performed searching for publications on laparoscopic fundoplication (LF), Transoral Incisionless Fundoplication (TIF), and laparoscopic MSA. The reported classified were separated according to their design into (group 1) large case-controlled series or comparative studies (n 100 cases) from high-volume centers and into (group 2) trials between different technologies of antireflux procedures, multicenter-studies, and meta-analyses of GERD-trials. Results: In total, 4030 abstract were screened according to the selected key words. Following the section criteria, 19 publications were selected and analyzed. Regarding group 1 and LF (selected studies 2565 patients), the morbidity ranged from 2.0-4.8 % of cases. With a follow-up time of 36-222 months most of these patients were followed 5 years. In group 2, more than 150 studies and several multicenter-registries were summarized in these 9 selected publications. The overall follow-up periods were substantially shorter with a range of 7-48 months. Conclusions: It can be concluded that special efforts in patient management in high volume centers and a vast experience may substantially contribute to excellent results for several antireflux techniques, which may reach a level of quality above results of registries and meta-analyses.

Nanoclay-based sensor composites for the facile detection of molecular antioxidants.

The detection and quantification of antioxidant molecules is an important task in food science, the fine chemical industry and healthcare. Antioxidants help in preventing the deterioration of nutrition and healthcare products, while eliminating over-the-limit exogenic reactive species, which may lead to illnesses. In our contribution, an inexpensive and rapid method to determine the concentration of various molecular antioxidants was developed. The principle of the analysis relies on the cupric ion reducing antioxidant capacity (CuPRAC) method, which is based on the color-changing reduction of chelated Cu2+ ions. This complex was successfully immobilized on an alginate-functionalized layered double hydroxide (dLDH) nanosheet via electrostatic interactions. The synthesis conditions of alginate (NaAlg) and the cupric complex were optimized, and the optimized composite was fabricated on cellulose paper to obtain a sensing platform. The paper-based sensor was superior to the ones prepared without the dLDH support, as the limit of detection (LOD) values decreased, and the linearity ranges broadened. The results offer a single-point measurement to evaluate the antioxidant efficiency in a cuvette-based method. The superior ability of the sensor was assigned to the presence of solid dLDH particles, as they offer adsorption sites for the dissolved antioxidant molecules, which contributes significantly to the decrease of the diffusion limitation during the detection process.

Analysis of Three-Dimensional Cell Migration in Dopamine-Modified Poly(aspartic acid)-Based Hydrogels.

Several types of promising cell-based therapies for tissue regeneration have been developing worldwide. However, for successful therapeutical application of cells in this field, appropriate scaffolds are also required. Recently, the research for suitable scaffolds has been focusing on polymer hydrogels due to their similarity to the extracellular matrix. The main limitation regarding amino acid-based hydrogels is their difficult and expensive preparation, which can be avoided by using poly(aspartamide) (PASP)-based hydrogels. PASP-based materials can be chemically modified with various bioactive molecules for the final application purpose. In this study, dopamine containing PASP-based scaffolds is investigated, since dopamine influences several cell biological processes, such as adhesion, migration, proliferation, and differentiation, according to the literature. Periodontal ligament cells (PDLCs) of neuroectodermal origin and SH-SY5Y neuroblastoma cell line were used for the in vitro experiments. The chemical structure of the polymers and hydrogels was proved by 1H-NMR and FTIR spectroscopy. Scanning electron microscopical (SEM) images confirmed the suitable pore size range of the hydrogels for cell migration. Cell viability assay was carried out according to a standardized protocol using the WST-1 reagent. To visualize three-dimensional cell distribution in the hydrogel matrix, two-photon microscopy was used. According to our results, dopamine containing PASP gels can facilitate vertical cell penetration from the top of the hydrogel in the depth of around 4 cell layers (~150 µm). To quantify these observations, a detailed image analysis process was developed and firstly introduced in this paper.

Pathophysiology of gastroesophageal reflux disease-which factors are important?

BACKGROUND: Pathophysiology of gastroesophageal reflux disease (GERD) shows a multifactorial background. Different anatomical and functional alterations can be determined such as weakness of the lower esophageal sphincter (LES), changes in anatomy by a hiatal hernia (HH), an impaired esophageal motility (IEM), and/or an associated gastric motility problem with either duodeno-gastro-esophageal reflux (DGER) or delayed gastric emptying (DGE). The purpose of this study is to assess a large GERD-patient population to quantitatively determine different pathophysiologic factors contributing to the disease. METHODS: For this analysis only patients with documented GERD (pathologic esophageal acid exposure) were selected from a prospectively maintained databank. Investigations: history and physical, body mass index, endoscopy, esophageal manometry, 24 h-pH-monitoring, 24 h-bilirbine-monitoring, radiographic-gastric-emptying or scintigraphy, gastrointestinal quality of life index (GIQLI). RESULTS: In total, 728 patients (420 males; 308 females) were selected for this analysis. Mean age: 49.9 years; mean BMI: 27.2 kg/m2 (range, 20-45 kg/m2); mean GIQLI of 91 (range: 43-138; normal level: 121); no esophagitis: 30.6%; minor esophagitis (Savary-Miller type 1 or Los Angeles Grade A): 22.4%; esophagitis [2-4]/B-D: 36.2%; Barrett's esophagus 10%. Presence of pathophysiologic factors: HH 95.4%; LES-incompetence 88%, DGER 55%, obesity 25.6%, IEM 8.8%, DGE 6.8%. CONCLUSIONS: In our evaluation of GERD patients, the most important pathophysiologic components are anatomical alterations (HH), LES-incompetence and DGER.

Hyaluronic Acid Is an Effective Dermal Filler for Lip Augmentation: A Meta-Analysis.

Introduction: The lips and the mouth play an indispensable role in vocalization, mastication and face aesthetics. Various noxious factors may alter and destruct the original structure, and appearance of the lips and the anatomical area surrounding the mouth. The application of hyaluronic acid (HA) may serve as a safe method for lip regeneration. Although a number of studies exist for HA effectiveness and safety, its beneficial effect is not well-established. Aim: The present meta-analysis and systematic review was performed to investigate the effectiveness of HA on lip augmentation. We also investigated the types and nature of adverse effects (AEs) of HA application. Methods: We reported our meta-analysis in accordance with the PRISMA Statement. PROSPERO protocol registration: CRD42018102899. We performed the systematic literature search in CENTRAL, Embase, and MEDLINE. Randomized controlled trials, cohort studies, case series and case reports were included. The untransformed proportion (random-effects, DerSimonian-Laird method) of responder rate to HA injection was calculated. For treatment related AEs descriptive statistics were used. Results: The systematic literature search yielded 32 eligible records for descriptive statistics and 10 records for quantitative synthesis. The results indicated that the overall estimate of responders (percentage of subjects with increased lip fullness by one point or higher) was 91% (ES = 0.91, 95% CI:0.85-0.96) 2 months after injection. The rate of responders was 74% (ES = 0.74, 95% CI:0.66-0.82) and 46% (ES = 0.46, 95% CI:0.28-0.65) after 6 and 12 months, respectively. We included 1,496 participants for estimating the event rates of AEs. The most frequent treatment-related AEs were tenderness (88.8%), injection site swelling (74.3%) and bruising (39.5%). Rare AEs included foreign body granulomas (0.6%), herpes labialis (0.6%) and angioedema (0.3%). Conclusion: Our meta-analysis revealed that lip augmentation with injectable HA is an efficient method for increasing lip fullness for at least up to 6 months after augmentation. Moreover, we found that most AEs of HA treatment were mild or moderate, but a small number of serious adverse effects were also found. In conclusion, further well-designed RCTs are still needed to make the presently available evidence stronger.

Poly(amino acid) based fibrous membranes with tuneable in vivo biodegradation.

In this work two types of biodegradable polysuccinimide-based, electrospun fibrous membranes are presented. One contains disulfide bonds exhibiting a shorter (3 days) in vivo biodegradation time, while the other one has alkyl crosslinks and a longer biodegradation time (more than 7 days). According to the mechanical measurements, the tensile strength of the membranes is comparable to those of soft the connective tissues and visceral tissues. Furthermore, the suture retention test suggests, that the membranes would withstand surgical handling and in vivo fixation. The in vivo biocompatibility study demonstrates how membranes undergo in vivo hydrolysis and by the 3rd day they become poly(aspartic acid) fibrous membranes, which can be then enzymatically degraded. After one week, the disulfide crosslinked membranes almost completely degrade, while the alkyl-chain crosslinked ones mildly lose their integrity as the surrounding tissue invades them. Histopathology revealed mild acute inflammation, which diminished to a minimal level after seven days.

Oxidation of Cysteinate Anions Immobilized in the Interlamellar Space of CaAl-Layered Double Hydroxide.

L-Cysteinate-intercalated CaAl-layered double hydroxide (LDH) was prepared by the co-precipitation method producing highly crystalline hydrocalumite phase with a well-pillared interlayer gallery. The obtained materials were characterized by X-ray diffractometry, IR as well as Raman spectroscopies. By performing interlamellar oxidation reactions with peracetic acid as oxidant, oxidation of cysteinate to cystinate in aqueous and cysteinate sulfenic acid in acetonic suspensions occurred. The oxidations could be performed under mild conditions, at room temperature, under neutral pH and in air. It has been shown that the transformation pathways are due to the presence of the layered structure, that is, the confined space of the LDH behaved as molecular reactor.

STRO-1 positive cell expansion during osteogenic differentiation: A comparative study of three mesenchymal stem cell types of dental origin.

OBJECTIVE: Although the osteogenic differentiation potential of mesenchymal stem cells of dental origin is well established, the roles of different marker proteins in this process remain to be clarified. Our aim was to compare the cellular and molecular changes, focusing in particular on mesenchymal stem cell markers, during in vitro osteogenesis in three dental stem cell types: dental follicle stem cells (DFSCs), periodontal ligament stem cells (PDLSCs) and dental pulp stem cells (DPSCs). DESIGN: Human DFSCs, PDLSCs and DPSCs were isolated, cultured and their osteogenic differentiation was induced for 3 weeks. Mineralization was assessed by von Kossa staining and calcium concentration measurements. The expression of mesenchymal and osteogenic markers was studied by immunocytochemistry and qPCR techniques. Alkaline phosphatase (ALP) activity and the frequency of STRO-1 positive cells were also quantified. RESULTS: The three cultures all showed abundant mineralization, with high calcium content by day 21. The expression of vimentin and nestin was sustained after osteogenic induction. The osteogenic medium induced a considerable elevation of STRO-1 positive cells. By day 7, the ALP mRNA level had increased more than 100-fold in DFSCs, PDLSCs, and DPSCs. Quantitative PCR results indicated dissimilarities of osteoblastic marker levels in the three dental stem cell cultures. CONCLUSIONS: DFSCs, PDLSCs and DPSCs have similar functional osteogenic differentiation capacities although their expressional profiles of key osteogenic markers show considerable variations. The STRO-1 positive cell fraction expands during osteogenic differentiation while vimentin and nestin expression remain high. For identification of stemness, functional studies rather than marker expressions are needed.

Investigation of the Cytotoxicity of Electrospun Polysuccinimide-Based Fiber Mats.

This study investigated cell viability in the presence of allylamine-modified and plasma-treated electrospun polysuccinimide fiber mats (PSI-AAmp). Low pressure non-equilibrium plasma was used for crosslinking the PSI-AAm. Comparison of FTIR and XPS analyses demonstrated that crosslinking occurred on the surface of the samples. Cell viability was investigated using the MG-63 osteosarcoma cell line and WST-1 viability reagent. Since PSI hydrolyzes to poly(aspartic acid) (PASP), PASP was used in addition to the regular controls (cells only). Phase contrast showed normal morphology in all cases at 24 h; however, in the presence of PSI-AAmp at 72 h, some rounded, dead cells could also be seen, and proliferation was inhibited. Since proliferation in the presence of PASP alone was not inhibited, the cause of inhibition was not the final product of the hydrolysis. Further investigations will be carried out to pinpoint the cause.