Physico-chemical and biological characterization of synthetic and eggshell derived nanohydroxyapatite/carboxymethyl chitosan composites for pulp-dentin tissue engineering.

Hybrid nanohydroxyapatite/carboxymethyl chitosan (nHAp-CMC) scaffolds have garnered significant attention in the field of regenerative engineering. The current study comparatively analyzed the physicochemical and biological properties of synthetic nanohydroxyapatite (SnHA)- and eggshell-sourced nanohydroxyapatite (EnHA)- based CMC biocomposites for pulp-dentin regeneration. EnHA and CMC were synthesized through a chemical process, whereas SnHA was commercially obtained. Composite scaffolds of SnHA-CMC and EnHA-CMC (1:5 w/w) were prepared using freeze-drying method. All biomaterials were characterized by FTIR, micro-Raman, XRD, HRSEM-EDX, and TEM analyses, and their in vitro bioactivity was assessed by immersing them in simulated body fluid for 21 days. The biological properties of the composite scaffolds were evaluated by assessing cytocompatibility using MTT assay and biomineralization potential by analyzing the odontogenic gene expressions (ALP, DSPP, DMP-1 and VEGF) in human dental pulp stem cells (DPSCs) using RT-qPCR method. Characterization studies revealed that EnHA displayed higher crystallinity and superior surface morphology compared to SnHA. The composite scaffolds showed a highly interconnected porous microstructure with pore sizes ranging between 60 and 220 µm, ideal for cell seeding. All tested materials, SnHA, EnHA, and their respective composites, displayed high cytocompatibility, increased ALP activity and degree of mineralization with significant upregulation of odontogenic-related genes on DPSCs (p < 0.05). Nevertheless, the odontogenic differentiation potential of EnHA-CMC on DPSCs was significantly higher when compared to SnHA-CMC. The findings from this study highlight the potential of EnHA-CMC as a promising candidate for pulp-dentin engineering.

Biomimetic dentin remineralization using eggshell derived nanohydroxyapatite with and without carboxymethyl chitosan - An in vitro study.

The objective of this study was to evaluate the synergistic effect of eggshell-derived nanohydroxyapatite (EnHA) and carboxymethyl chitosan (CMC) in remineralizing artificially induced dentinal lesions. EnHA and CMC were synthesized using simple chemical processes and characterized using FTIR, XRD, HRSEM-EDX, TEM, DLS and TGA/DTA analyses. A total of 64 pre-demineralized coronal dentin specimens were randomly subjected to following treatments (n = 16):artificial saliva (AS), EnHA, CMC, and EnHA-CMC, followed by pH cycling for 7 days. HRSEM-EDX, Vickers-indenter, and micro-Raman analyses were used to assess surface-topography, microhardness, and chemical analysis, respectively. All tested materials demonstrated non-cytotoxicity when assessed on hDPSCs using MTT assay. FTIR, XRD and thermal analyses confirmed the characteristics of both EnHA and CMC. EnHA showed irregular rod-shaped nanoparticles (30-70 nm) with the presence of Ca,P,Na, and Mg ions. Dentin treated with EnHA-CMC exhibited complete tubular occlusion and highest microhardness whereas the AS group revealed the least mineral deposits (p < 0.05). No significant differences were observed between EnHA and CMC groups (p > 0.05). In addition, molecular conformation analysis revealed peak intensities in collagen's polypeptide chains in dentin treated with CMC and EnHA-CMC, whereas other groups showed poor collagen stability. The results highlighted that EnHA-CMC aided in rapid and effective biomineralization, suggesting its potential as a therapeutic solution for treating dentin caries.

Comparative Analysis of Determinants and Outcome of Early and Late Acute Antibody Mediated Rejection (ABMR).

Introduction: Antibody-mediated rejection (ABMR) is one of the major determinants of graft survival. Although diagnostic precision and treatment options have improved, response to therapy and graft survival has not improved very significantly. The phenotypes of early and late acute ABMR differ in many ways. In this study, we assessed the clinical characteristics, response to therapy, DSA positivity, and outcomes of early and late ABMR. Methods: During the study period, 69 patients with acute ABMR diagnosed on renal graft histopathology were included with a median follow-up of 10 months after rejection. Recipients were stratified into early acute ABMR (<3 months of transplant; n = 29) and late acute ABMR (>3 months of transplant; n = 40). Graft survival, patient survival, response to therapy, and doubling of serum creatinine were assessed and compared between the two groups. Results: Baseline characteristics and immunosuppression protocols were comparable between the early and late ABMR groups. Late acute ABMR had an increased risk of doubling of serum creatinine than the early ABMR group (P = 0.002). Graft and patient survival were not statistically different between the two groups. Response to therapy was inferior in the late acute ABMR group (P = 0.00). Pretransplant DSA was present in 27.6% in the early ABMR group. Late acute ABMR was frequently associated with nonadherence or suboptimal immunosuppression and low DSA positivity (15%). Infections such as CMV, bacterial, and fungal infections were similar in the earlier and late ABMR groups. Conclusion: Late acute ABMR group had a poor response to anti-rejection therapy and also an increased risk of doubling of serum creatinine compared to the early acute ABMR group. There was also a tendency toward increased graft loss in late acute ABMR patients. Late acute ABMR patients are more frequently associated with nonadherence/suboptimal immunosuppression. There was also a low incidence of anti-HLA DSA positivity in late ABMR.

Characterization of nano-hydroxyapatite incorporated carboxymethyl chitosan composite on human dental pulp stem cells.

AIM: To compare the odontogenic differentiation potential of a composite scaffold (CSHA) comprising of nano-hydroxyapatite (nHAp) and carboxymethyl chitosan (CMC) with Biodentine on human dental pulp stem cells (hDPSCs). METHODOLOGY: A CSHA scaffold was prepared through an ultrasonication route by adding nHAp and CMC (1:5 w/w) in water medium followed by freeze-drying. Physicochemical characterization was achieved using scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray diffraction and Fourier transform infrared spectroscopy. In-vitro bioactivity and pH assessments were done by soaking in simulated body fluid (SBF) for 28 days. The angiogenic and odontogenic differentiation abilities were assessed by expression of vascular endothelial growth factor (VEGF) and Dentine sialophosphoprotein (DSPP) markers on cultured hDPSCs by flow cytometry and RT-qPCR at 7, 14 and 21 days. Cell viability/proliferation and biomineralization abilities of CSHA were compared with Biodentine by MTT assay, alkaline phosphatase (ALP) activity, Alizarin Red Staining (ARS) and osteopontin (OPN) expression on hDPSCs following 7 and 14 days. Data were statistically analysed with Kruskal Wallis and Friedman tests as well as one way anova followed by appropriate post hoc tests (p < .05). RESULTS: Characterization experiments revealed a porous microstructure of CSHA with pore diameter ranging between 60 and 200 µm and 1.67 Ca/P molar ratio along with the characteristic functional groups of both HAp and CMC. CSHA displayed bioactivity in SBF by forming apatite-like crystals and maintained a consistent pH value of 7.70 during 28 days' in vitro studies. CSHA significantly upregulated VEGF and DSPP levels on hDPSCs on day 21 compared with day 7 (p < .05). Further, CSHA supported cell viability/proliferation over 14 days like Biodentine with no statistical differences (p > .05). However, CSHA exhibited increased ALP and ARS activity with an intense OPN staining compared with Biodentine after 14 days (p < .05). CONCLUSION: The results highlighted the odontogenic differentiation and biomineralization abilities of CSHA on hDPSCs with significant VEGF and DSPP gene upregulations. Further, CSHA exhibited enhanced mineralization activity than Biodentine, as evidenced by increased ALP, ARS and OPN activity on day 14. The nHAp-CMC scaffold has the potential to act as an effective pulp capping agent; however, this needs to be further validated through in-vivo animal studies.

Eggshell derived nano-hydroxyapatite incorporated carboxymethyl chitosan scaffold for dentine regeneration: A laboratory investigation.

AIM: To assess odontogenic differentiation abilities of porous biomineralizable composite scaffolds comprising eggshell derived nano-hydroxyapatite (HAnp) and carboxymethyl chitosan (CMC) on cultured human dental pulp stem cells (hDPSCs). METHODOLOGY: Nano-hydroxyapatite was derived from eggshells using a simple combustion method and CMC was prepared from chitosan through a chemical route. Several compositions of HAnp-CMC (0:5, 5:0, 1:5, 2:5, 3:5, 4:5 and 1:1 w/w%) scaffolds were prepared by magnetic stirring and freeze-drying methods. HAnp-CMC scaffolds were characterized using high-resolution scanning electron microscopy combined with energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction methods. In vitro bioactivity was determined following the interaction in simulated body fluid for 21 days. The optimized composite was then loaded onto hDPSCs to assess cell viability/proliferation, dentine sialophosphoprotein (DSPP) and vascular endothelial growth factor (VEGF) expressions using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, real-time quantitative polymerase chain reaction and flow cytometry methods, respectively, following 7, 14 and 21 days. For intergroup and intragroup comparisons, Kruskal-Wallis and Friedman tests were employed, respectively, followed by appropriate post hoc test (Dunn). Significant levels were set at *p < .05 and *p < .01. RESULTS: Synthesized hydroxyapatite (HAp) comprised crystals ranging from 20 to 50 nm (HAnp) with spherulite morphology and calcium/phosphorus (Ca/P) molar ratio of 1.67. The ultrastructure of all the scaffolds revealed a highly interconnected porous microstructure, whilst the chemical characterization displayed specific functional groups of both HAnp and CMC. In vitro bioactivity assessment confirmed the biomineralization potential of all scaffolds with an apatite-like crystal formation on the surface. The 1:5 HAnp-CMC revealed a favourable pore size (60-180 µm) that was suitable for cell seeding and was chosen for further experiments. Cell viability/proliferation rates of hDPSCs loaded 1:5 HAnp-CMC at 21st day was significantly greater than that at 7th day (p < .05). The mean relative quantification of DSPP expression by the scaffold was significantly higher (p < .05) on day 21 (3.16) than on day 7 (1.67). Mean fluorescence intensity of the VEGF expression at day 21 (32.5) was also significantly higher (p < .01) than at day 7 (12.54). CONCLUSION: hDPSCs on 1:5 HAnp-CMC scaffolds displayed increased cell viability/proliferation and enhanced DSPP as well as VEGF expressions. The 1:5 HAnp-CMC composite has the potential to serve as a promising scaffold for dentine regeneration.

A spectroscopic assessment of interaction between 4% articaine hydrochloride with adrenaline and various endodontic irrigants.

BACKGROUND: Interaction between 2% lidocaine HCl (with and without adrenaline) and sodium hypochlorite (NaOCl) resulted in a toxic precipitate formation. The aim of this in vitro study was to assess the interaction between 4% articaine hydrochloride with adrenaline (AHa) and commonly used endodontic irrigants 3% NaOCl, 2% chlorhexidine (CHX), and 17% ethylenediaminetetraacetic acid (EDTA) using spectroscopic analyses. MATERIALS AND METHODS: In this in vitro study, 3% NaOCl, 2% CHX, and 17% EDTA were mixed with 4% AHa individually. 1.7 ml of 4% AHa from the cartridge was mixed with 1.7 ml of each test irrigants. The solutions were subjected to a preliminary ultraviolet spectroscopic (UVS) analysis to assess forpotential interactions (if any). If the interaction was detected, the test solutions were further subjected to nuclear magnetic resonance (NMR) analysis for characterization. The precipitate formed (if any) was then subjected to NMR analysis. RESULTS: UVS analysis revealed a bathochromic shift when 3% NaOCl and 2% CHX were mixed with 4% AHa, respectively. This shift was not observed when EDTA was mixed with 4% AHa. 1H and 13C NMR spectra confirmed the interaction between 3% NaOCl with 4% AHa, which resulted in a precipitate formation, methyl 3-amino-4-methylthiophene-2-carboxylate (MAMC). The analysis of 1H NMR spectra showed peaks at 7.1 ppm, 2.21 ppm, and 9.93 ppm, respectively, which corresponds to aromatic ring protons. A peak at 3.8 ppm was assigned to methyl proton of methyl ester. The characteristic appearance of peaks at 14.82 and 51.16 ppm corresponds to aliphatic carbons. The five peaks occurring at 126, 134.5, 139.2, 156.5, and 162.9 ppm correspond to the aromatic carbon atoms present in the thiophene unit. NMR spectra revealed no interaction between 2% CHX and 4% AHa. 1H and 13C NMR spectra confirmed that 3% NaOCl interacted with 4% AHa, leading to the formation of a precipitate MAMC. CONCLUSION: 3% NaOCl interacted with 4% AHa leading to the formation of a precipitate MAMC which is reported to exhibit the least toxicity. Until the precipitate is studied further, it would be advisable to avoid the immediate use of NaOCl following administration of intrapulpal anesthetic solution with articaine hydrochloride (with adrenaline).

Clinical Characteristics, Patient and Technique Survival in Elderly Patients on Peritoneal Dialysis.

The outcomes of the elderly population on peritoneal dialysis (PD) in developing countries are less known. In this study, we intended to study the clinical characteristics and patient and technique survival of elderly patients on PD. In this study, data of 148 elderly patients with end-stage renal disease who initiated PD between January 2001 and December 2015 were collected. Baseline clinical characteristics and events during the study period were recorded. Overall patient and technique survival rates of diabetic and non-diabetic elderly patients on PD were analyzed. Around 128 patients who were initiated PD during the study period were included for final analysis. The mean age of the study group was 70.3 ± 5.1 years, and 94 (80%) were males. Among these, 79 (65.8%) had diabetes. At the end of the study period, only 20 (16.6%) patients were remained on PD. Eighty-four (70%) patients died during PD and 15 (12.5%) patients were transferred to hemodialysis during the study period. The main reasons for death were cardiovascular (56.6%) and sepsis due to peritonitis (18.8%). The mean patient survival time was 38.2 ± 2.6 months. The patient survival rates were 91.2%, 45.3%, and 22.8% at 1, 3, and 5 years, respectively. Predictors of mortality were increased serum phosphorus, peritonitis episodes, urine output <400 mL, and ultrafiltration <1000 mL/day at beginning of PD. The mean technique survival time was 92.0 ± 5.1 months. Technique survival rates at 1, 3, and 5 years were 94.8%, 85.3%, and 71.7%, respectively. None of the factors was found to be predictive of technique survival. We found no significant difference between diabetic and non-diabetic patients in terms of technique and patient survival. Mortality was higher in elderly patients on PD. Factors affecting mortality in elderly patients on PD are low urine output, low ultrafiltration at beginning of PD, high serum phosphorus, and presence of peritonitis episodes. Patient and technique survival rates were comparable between diabetic and non-diabetic elderly patients on PD.

Phase-dependent structural, optical, phonon and UV sensing properties of ZnS nanoparticles.

In order to investigate the influence of crystal structure on the photoresponse properties of ZnS nanoparticles under UV light exposure, electrical measurements on polyvinylpyrrolidone capepd cubic and hexagonal ZnS nanoparticles with average particle size 30-40 nm have been successfully carried out. Low-temperature solvothermal synthesis yields pure and highly crystalline w-ZnS nanoparticles with good stability. Different structures of prepared ZnS nanoparticles have been identified and confirmed with powder x-ray diffraction, high-resolution field-emission transmission electron microscopy and non-resonant Raman spectroscopic techniques, respectively. The energy band gap and emission properties of cubic and hexagonal ZnS have been studied using UV-vis absorption and photoluminescence spectroscopy. The interaction of phonons with free carriers and transport properties has a vital influence on the electronic and optical properties of nanomaterials. Hence, the resonant and non-resonant Raman spectral studies have been carried out for the prepared samples. Studies on the I-V characteristics and the mechanism behind the enhancement of photocurrent for the cubic and hexagonal ZnS nanoparticle-based photodetectors have shown an enhanced photocurrent for hexagonal ZnS nanoparticles rather than the cubic.

A Raman spectral probe on polar w-ZnS nanostructures and surface optical phonon modes in nanowires.

In the present study, different morphologies of ZnS nanostructures have been synthesized through a hydrothermal method and their Raman spectral modes are investigated. Raman scattering from surface optical (SO) modes has been seen and identified as a strange shoulder band of LO at 340 cm-1 in nanowires (NWs) with a hexagonal wurtzite structure of ZnS in air medium. X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques have been used to confirm the hexagonal phase and the modulation in the surface during the growth process, which causes the translational symmetry breaking to activate the SO mode. The appearance of a strong SO mode in NWs has been obviously confirmed by the frequency downshift of the SO mode in different dielectric media with dielectric constants ranging from 1 to 2.56. The SO phonon mode shift due to the roughness in the NW faces has been estimated from the wave-vector that activates the SO mode and an approximate dielectric continuum (DC) model has been used to understand the SO modes in NWs. The surface perturbation responsible for the activation of the SO mode has been estimated and is compared with the surface modulation along the growth axis of the NW from the TEM images.

Case-Mix, Care Processes, and Outcomes in Medically-Ill Patients Receiving Mechanical Ventilation in a Low-Resource Setting from Southern India: A Prospective Clinical Case Series.

BACKGROUND: Mechanical ventilation is a resource intensive organ support treatment, and historical studies from low-resource settings had reported a high mortality. We aimed to study the outcomes in patients receiving mechanical ventilation in a contemporary low-resource setting. METHODS: We prospectively studied the characteristics and outcomes (disease-related, mechanical ventilation-related, and process of care-related) in 237 adults mechanically ventilated for a medical illness at a teaching hospital in southern India during February 2011 to August 2012. Vital status of patients discharged from hospital was ascertained on Day 90 or later. RESULTS: Mean age of the patients was 40 ± 17 years; 140 (51%) were men. Poisoning and envenomation accounted for 98 (41%) of 237 admissions. In total, 87 (37%) patients died in-hospital; 16 (7%) died after discharge; 115 (49%) were alive at 90-day assessment; and 19 (8%) were lost to follow-up. Weaning was attempted in 171 (72%) patients; most patients (78 of 99 [79%]) failing the first attempt could be weaned off. Prolonged mechanical ventilation was required in 20 (8%) patients. Adherence to head-end elevation and deep vein thrombosis prophylaxis were 164 (69%) and 147 (62%) respectively. Risk of nosocomial infections particularly ventilator-associated pneumonia was high (57.2 per 1,000 ventilator-days). Higher APACHE II score quartiles (adjusted HR [95% CI] quartile 2, 2.65 [1.19-5.89]; quartile 3, 2.98 [1.24-7.15]; quartile 4, 5.78 [2.45-13.60]), and new-onset organ failure (2.98 [1.94-4.56]) were independently associated with the risk of death. Patients with poisoning had higher risk of reintubation (43% vs. 20%; P = 0.001) and ventilator-associated pneumonia (75% vs. 53%; P = 0.001). But, their mortality was significantly lower compared to the rest (24% vs. 44%; P = 0.002). CONCLUSIONS: The case-mix considerably differs from other settings. Mortality in this low-resource setting is similar to high-resource settings. But, further improvements in care processes and prevention of nosocomial infections are required.

Interaction between lidocaine hydrochloride (with and without adrenaline) and various irrigants: A nuclear magnetic resonance analysis.

BACKGROUND: Interaction between local anesthetic solution, lidocaine hydrochloride (with and without adrenaline), and root canal irrigants such as sodium hypochlorite (NaOCl), ethylene diamine tetra-acetic acid (EDTA), and chlorhexidine (CHX) has not been studied earlier. Hence, the purpose of this in vitro study was to evaluate the chemical interaction between 2% lidocaine hydrochloride (with and without adrenaline) and commonly used root canal irrigants, NaOCl, EDTA, and CHX. MATERIALS AND METHODS: SAMPLES WERE DIVIDED INTO EIGHT EXPERIMENTAL GROUPS: Group I-Lidocaine hydrochloride (with adrenaline)/3% NaOCl, Group II-Lidocaine hydrochloride (with adrenaline)/17% EDTA, Group III- Lidocaine hydrochloride (with adrenaline)/2% CHX, Group IV-Lidocaine hydrochloride (without adrenaline)/3% NaOCl, Group V-Lidocaine hydrochloride (without adrenaline)/17% EDTA, Group VI-Lidocaine hydrochloride (without adrenaline)/2% CHX, and two control groups: Group VII-Lidocaine hydrochloride (with adrenaline)/deionized water and Group VIII-Lidocaine hydrochloride (without adrenaline)/deionized water. The respective solutions of various groups were mixed in equal proportions (1 ml each) and observed for precipitate formation. Chemical composition of the formed precipitate was then analysed by nuclear magnetic resonance spectroscopy (NMR) and confirmed with diazotation test. RESULTS: In groups I and IV, a white precipitate was observed in all the samples on mixing the respective solutions, which showed a color change to reddish brown after 15 minutes. This precipitate was then analysed by NMR spectroscopy and was observed to be 2,6-xylidine, a reported toxic compound. The experimental groups II, III, V, and VI and control groups VII and VIII showed no precipitate formation in any of the respective samples, until 2 hours. CONCLUSION: Interaction between lidocaine hydrochloride (with and without adrenaline) and NaOCl showed precipitate formation containing 2,6-xylidine, a toxic compound.

Cerebral infarction leading to hemiplegia: A rare complication of acute pancreatitis.

Peripancreatic vascular thrombosis is a known complication of acute pancreatitis (AP) and chronic pancreatitis. However, hemiplegia resulting from cerebral infarction due to cerebral arterial thrombosis is a rare complication of AP. Here, we report a case of alcohol related severe AP with multi-organ dysfunction, which was complicated by large left sided middle cerebral artery territory infarct - leading to right sided hemiplegia in a 48-year-old male patient. The neurological and vascular thrombotic complications of pancreatitis, their pathogenesis and management are discussed in brief.