Design of biostable scaffold based on collagen crosslinked by dialdehyde chitosan with presence of gallic acid

In this study, we have prepared the biostable collagen scaffold which is crosslinked by dialdehyde chitosan (DAC) with presence of Gallic acid (GA) and characterized its physico-chemical, biostable and biocompatible properties. The digital photographic and scanning electron microscopic (SEM) images of the prepared collagen scaffold is exposed well with properly oriented interconnected porous natured structure. The appearance of diffraction peaks showed slightly crystalline characteristic when compared to others. The differential scanning calorimetric (DSC) and thermogravimetric analysis (TGA) measurements indicates well significantly increased denaturation temperature (T_D) and decreased decomposition rate. FT-IR result suggests the structural integrity of collagen which favours the molecular stability. The dialdehyde groups from DAC crosslinked with collagen functional groups that increase the molecular crosslinking owing to the large number of amino groups in its molecular chain. This scaffold exhibited 87% resistance against collagenolytic degradation by collagenase. The results showed that the improved biostability which prevents the free access of the collagenase to binds with the collagen triple helical chains. This scaffold confirm high biocompatibilities; enhanced cell proliferation and adhesions properties. This results gains new insight into the collagen scaffold to improves the biostability. This could be suitable method to preparation of collagenous biomaterials for tissue engineering applications.

Five-year evaluation of safety, efficacy and acceptability of Norplant implants in Nepal

This paper presents findings based on a five-year, noncomparative study of Norplant contraceptive subdermal implants in Nepal. The study was designed to evaluate the contraceptive safety, efficacy, and overall acceptability of Norplant. Four hundred and seven women enrolled in the clinical trial, which began in 1985, at two study sites, located in Patan and Kathmandu. Follow-up visits were scheduled at 1, 3 and 6 months after Norplant insertion and every six months thereafter until removal or at the end of five years. Although five pregnancies were reported during the study, only two women (one from each center) were diagnosed as becoming pregnant while using Norplant. The pooled gross cumulative life-table pregnancy rate was 0.6 per 100 women at the end of five years. The pooled cumulative continuation rate was 62 per 100 women at the end of five years. The three most frequently reported reasons for discontinuation were menstrual problems, personal reasons, and medical reasons. Of the 125 women who completed a five-year user satisfaction questionnaire, the majority of the women (86%) planned to continue using contraception after study completion. Of these women, almost one half said they planned to use a second Norplant set. The findings suggest that the Norplant system is a safe, effective, and acceptable method of contraception among Nepalese women.

Deciphering the interactions of phytochemicals with ovalbumin, the major food allergen from egg white: spectroscopic and computational studies

Ovalbumin (OVA), the major component of egg white, has been used as a model carrier protein to study the interaction of four bioactive phytochemicals 6-hydroxyflavone, chrysin, naringin, and naringenin. A static quenching mechanism was primarily associated with the complexation of the flavonoids with OVA. Hydrophobic forces play a major part in the stability of the complexes. The structural changes within the protein in response to flavonoid binding revealed a decrease in OVA's α-helical content. The hypothesized binding site for flavonoids in OVA overlaps with one or more immunoglobulin E-binding epitopes that may have some effect in the immunoglobulin E response pathway. The flavonoids remain in the same binding site throughout the simulation time and impart protein stability by forming different noncovalent interactions. This study presents comprehensive information about the interaction of the flavonoids with OVA and the associated structural variations after the binding, which might help researchers better comprehend similar medication pharmacodynamics and provide critical information for future therapeutic development.

BODIPY(aryl)iodonium salts in the efficient synthesis of diversely functionalized BODIPYs and selective detection of serum albumin

BODIPY(aryl)iodonium salts were readily accessible from the high-yielding reaction of BODIPY with iodoarenes or hydroxyl(tosyloxy)iodoarenes in the presence of m-CPBA. The prepared BODIPY(aryl)iodonium salts bearing substituents of varied electronic nature were utilized for the direct syntheses of thiocyanate, azide, amine and acrylate functionalized BODIPYs and β,β'-bis-BODIPYs. The regioselective syntheses of α-piperidinyl and β-piperidinyl substituted BODIPYs were achieved through the reaction of BODIPY(aryl)iodonium salts with piperidine in the absence and presence of copper(I). Expeditious and high yielding (79-82%) synthesis of β,β'-bis-BODIPYs was also developed through the palladium-catalyzed reductive coupling of the easily accessible BODIPY(aryl)iodonium salts. Some of the indole-appended BODIPYs and bis-BODIPYs displayed strong absorption in the visible region (∼610 nm). The BODIPY(aryl)iodonium salts also showed significant binding with serum albumin and were observed to be selective serum protein sensors with estimated limits of detection as low as 7 μg mL-1 in some cases.

Sydenham's Chorea with Silent Cardiac Lesions, Mimicking

Sydenham's chorea is an uncommon neurological manifestation of rheumatic fever and has many and varied differential diagnosis. It may mimic encephalitis when presents as an isolated feature even when silent cardiac lesions are present. Early diagnosis, treatment and penicillin prophylaxis prevents recurrence and progression of cardiac lesions. Prompt symptomatic relief and alleviation of distress is obtained with therapeutic intervention. A case of rheumatic chorea with silent cardiac valve lesions which mimicked herpes simplex encephalitis with choreoathetosis, in a 13 year old girl is presented along with review of literature.

Exploring the impact of novel thiazole-pyrazole fused benzo-coumarin derivatives on human serum albumin: Synthesis, photophysical properties, anti-cholinergic activity, and interaction studies

Derivatives of thiazole-pyrazole fused benzo-coumarin compounds were successfully synthesized and characterized, followed by a comprehensive spectroscopic investigation on various photophysical properties in different media. The multipronged approach using steady state and time resolved fluorescence spectroscopy pointed out the impact of substitution in the estimated spectroscopic and other physicochemical properties of the systems. Further, the evaluation of anti-acetylcholinesterase (anti-AChE) activity yielded significant insight into the therapeutic potential of the synthesized coumarinyl compounds for the treatment of Alzheimer's disease (AD). The findings revealed a non-competitive mode of inhibition mechanism, with an estimated IC50 value of 67.72 ± 2.00 nM observed for one of the investigated systems as AChE inhibitor. Notably, this value is even lower than that of an FDA-approved AD drug Donepezil (DON), indicating the enhanced potency of the coumarin derivatives in inhibiting AChE. Interestingly, significant diminution in inhibition was observed in presence of human serum albumin (HSA) as evidenced by the relative increase in IC50 value by 8 ∼ 39 % in different cases, which emphasized the role of albumin proteins to control therapeutic efficacies of potential medications. In-depth spectroscopic and in-silico analysis quantified the nature of interactions of the investigated systems with HSA and AChE. Overall, the outcomes of this study provide significant understanding into the biophysical characteristics of novel thiazole-pyrazole fused benzo-coumarin systems, which could aid in the development of new cholinergic agents for the treatment of AD and materials based on coumarin motifs.

Iodine(III)-promoted regioselective and efficient synthesis of β-triazolyl BODIPYs for the selective recognition of nickel ion and bovine serum albumin

Various ꞵ-triazolyl tethered BODIPYs were efficiently prepared in a sequential one-pot protocol involving the initial reaction of BODIPY with iodobenzene diacetate (IBD) and sodium azide to in situ generate BODIPY...