Accelerated full-thickness skin wound tissue regeneration by self-crosslinked chitosan hydrogel films reinforced by oxidized CNC-AgNPs stabilized Pickering emulsion for quercetin delivery.

BACKGROUND: The non-toxic self-crosslinked hydrogel films designed from biocompatible materials allow for controlled drug release and have gathered remarkable attention from healthcare professionals as wound dressing materials. Thus, in the current study the chitosan (CS) film is infused with oil-in-water Pickering emulsion (PE) loaded with bioactive compound quercetin (Qu) and stabilized by dialdehyde cellulose nanocrystal-silver nanoparticles (DCNC-AgNPs). The DCNC-AgNPs play a dual role in stabilizing PE and are involved in the self-crosslinking with CS films. Also, this film could combine the advantage of the controlled release and synergistic wound-healing effect of Qu and AgNPs. RESULTS: The DCNC-AgNPs were synthesized using sodium periodate oxidation of CNC. The DCNC-AgNPs were used to stabilize oil-in-water PE loaded with Qu in its oil phase by high speed homogenization. Stable PEs were prepared by 20% v/v oil: water ratio with maximum encapsulation of Qu in the oil phase. The Qu-loaded PE was then added to CS solution (50% v/v) to prepare self-crosslinked films (CS-PE-Qu). After grafting CS films with PE, the surface and cross-sectional SEM images show an inter-penetrated network within the matrix between DCNC and CS due to the formation of a Schiff base bond between the reactive aldehyde groups of DCNC-AgNPs and amino groups of CS. Further, the addition of glycerol influenced the extensibility, swelling ratio, and drug release of the films. The fabricated CS-PE-Qu films were analyzed for their wound healing and tissue regeneration potential using cell scratch assay and full-thickness excisional skin wound model in mice. The as-fabricated CS-PE-Qu films showed great biocompatibility, increased HaCat cell migration, and promoted collagen synthesis in HDFa cells. In addition, the CS-PE-Qu films exhibited non-hemolysis and improved wound closure rate in mice compared to CS, CS-Qu, and CS-blank PE. The H&E staining of the wounded skin tissue indicated the wounded tissue regeneration in CS-PE-Qu films treated mice. CONCLUSION: Results obtained here confirm the wound healing benefits of CS-PE-Qu films and project them as promising biocompatible material and well suited for full-thickness wound healing in clinical applications.

Miscibility, thermal degradation and rheological analysis of epoxy/MABS blends.

The effect of the addition of the methyl methacrylate acrylonitrile butadiene styrene (MABS) copolymer on the miscibility, thermal degradation and rheological properties of epoxy systems is described. Epoxy resin/MABS blends containing 5, 10, 15 and 20 phr MABS were prepared using the solution mixing technique. Homogenous blends obtained using this technique have undergone a polymerization reaction induced phase separation process by the introduction of the curing agent 4,4'-diaminodiphenyl sulfone (DDS). The isothermal rheology at four different temperatures, 150, 160, 170 and 180 °C, was used to examine the effect of MABS on the gelation and vitrification time. The evolution of storage modulus, loss modulus and tan delta was found to be closely related to the evolution of complex phase separation. The increase in the complex viscosity during curing was determined by in situ rheometry and theoretically analysed by fitting with the Williams-Landell-Ferry equation. An exponential increase in complex viscosity was observed, which was induced by cross-linking. The variation of Tg before and after curing was studied using DSC analysis and dynamic kinetic modeling of the curing process was carried out by utilizing dynamic DSC scans. Thermal stability studies of completely cured epoxy/MABS blends using thermogravimetric analysis revealed that all the blends and neat epoxy exhibited single step degradation. Thermal degradation kinetics was calculated using the Coats Redfern equation.

An overview of viscoelastic phase separation in epoxy based blends.

The viscoelastic effects during reaction induced phase separation play an important role in toughening epoxy-based blends. The large difference in molecular weight/glass transition temperature between the blend components before the curing reaction results in dynamic asymmetry, causing viscoelastic effects during phase separation accompanying the curing reaction. This review will focus on the key factors responsible for viscoelastic phase separation in epoxy-based blends and hybrid nanocomposites. Time-resolved characterization techniques such as rheometry, small angle laser light scattering, optical microscopy etc., are mainly used for monitoring the viscoelastic effects during phase separation. Incorporation of nanofillers in epoxy thermoplastic blends enhances the viscoelastic phase separation due to the increase in dynamic asymmetry. Different theoretical models are identified for the determination of processing parameters such as temperature, viscosity, phase domain size, and other parameters during the viscoelastic phase separation process. The effect of viscoelastic phase separation has a very strong influence on the domain parameters of the blends and thereby on the ultimate properties and applications.

ThermOxshield ion pair self assembly unleashing suppressed release.

Poly (acrylic acid) (PAA), an anionic polymer was used to prepare ion pair self-assembly (IPSAM) with 4-(methylthio)aniline (MTA), a hydrophobic counter ion, which is responsive to temperature and oxidation. The IPSAM was formed when the carboxylic to amino group molar ratio was 7/3-5/5. The structure of the IPSAM nanoparticle was spherical whose diameter was 30-40 nm on the TEM images. The PAA/MTA ion pair showed the upper critical solution temperature (UCST) that hiked with increasing MTA content. When the MTA of the ion pair was oxidized by H2O2, the UCST was also increased. The amphiphilic property of the ion pair was responsible for interface activity which declined upon the oxidation of the MTA. The surface tension was low for the ratio of PAA/MTA (5/5), which made the 5/5 ratio suitable for further studies. The interaction between PAA and MTA, which was ionic, and the oxidation of MTA was confirmed by FT-IR spectroscopy. The release of payload (i.e. Nile red) in IPSAM was restrained below the UCST but it was triggered above the phase transition temperature possibly due to the disintegration of the IPSAM whereas on MTA oxidation the release was shielded due to more hydrophobicity. The release was found to be higher in tumor environment temperature which could be controlled with the input concentration of H2O2 giving a stable IPSAM. The cell viability results showed that IPSAM has no significant cytotoxicity and can serve as a drug carrier for stimulus-response.

Experience of Domestic Violence and Psychological Morbidity in Spouses of Alcohol-Dependent Males.

BACKGROUND: Prevalence of both domestic violence (DV) and alcohol use is reported to be high in Kerala. The prevalence of DV and psychological morbidity in spouses of alcohol-dependent males has not been studied objectively. METHODS: This cross-sectional study was undertaken to study the occurrence of DV and psychological morbidity-major depressive disorder (MDD), anxiety disorders, and adjustment disorders-in spouses of alcohol-dependent males attending the de-addiction center of a tertiary care hospital in South India. Sixty consecutive cases, aged 18-55 years, were recruited after getting informed consent. They were assessed using Domestic Violence Questionnaire (DVQ), Mini International Neuropsychiatric Interview Schedule, and a questionnaire to assess adjustment disorder. The association of DV with psychological morbidities was also studied. RESULTS: DV was reported by 41 (68.3%, 95% confidence interval [CI] = 55.0-79.7) cases. At least one psychiatric morbidity was observed in 51 (85.0%, 95% CI = 72.9-92.5) cases-MDD in 15 (25.0%, 95% CI = 15.1-38.1), anxiety disorders in 6 (10%, 95% CI = 4.1-21.2), and adjustment disorder in 32 (53.3%, 95% CI = 40.1-66.1) cases each. No statistically significant association was observed between DV and any of the psychiatric disorders. However, DVQ scores showed significant correlation with years of marriage (Pearson's r = 0.268, P < 0.05) and with stressful life events over the past 1 year (Pearson's r = 0.424, P < 0.05). CONCLUSIONS: High rates of DV and psychological morbidity were seen in spouses of alcohol-dependent males.

Burden and resilience in caregivers of patients on maintenance haemodialysis

Background: Chronic renal failure is one among the chronic illness which due to persistence of the disease has various effects on the physiological, psychological and functional ability of the patient and his family. Although haemodialysis has become a highly safe medical procedure that significantly extended life of such patients, it is nevertheless a stressful and lengthy treatment process. The task of personal life care for such patients falls primarily on the family members. The caregiver is expected to aid in patient’s daily life activities resulting in increased physical and emotional burden. With the considerable level of burden involved the concept of resilience thus become crucial as they could function as protective factors. The current study aims to assess the level of caregiver burden and resilience in caregivers of haemodialysis patients.Methods: A cross sectional observational study was done in 120 caregivers of patients diagnosed as having ESRD on maintenance hemodialysis. Zarit Burden Interview was used for assessing caregiver’s burden. Brief Resilience Scale was used to assess caregiver’s resilience.Results: 35.8% of caregivers had severe caregiver burden while looking after dialysis patients while 45% of caregivers had moderate burden. Caregivers showed low resilience about 72.5% which displays poor problem solving and emotion-focused coping strategies.Conclusions: The study shows that more than 80% of caregivers suffered from moderate to severe burden and poor resilience among them would be a contributing factor. The study also shows that female caregivers were most affected. The burden was significantly higher in caregivers as the years spent on caregiving increased and more hours spent per day looking after the patients. Health-care providers need to address these concerns based on both patient- and caregiver-focused approaches, rather than only patient focused.