Heavy metal contamination in the complete stretch of Yamuna river: A fuzzy logic approach for comprehensive health risk assessment.

River Yamuna is one of the most sacred major tributaries of river Ganga. This study aimed to assess the level of heavy metals in monsoon and non-monsoon season in river Yamuna in Uttar Pradesh, India and to assess the possible source of contamination and its associated health risk. Except for iron (Fe), the mean levels of all metals were within drinking water safe limits in both seasons. Except for chromium (Cr), lower values were observed for other metals in the monsoon season could be attributed dilution effect. Multivariate analysis indicated that both geogenic and anthropogenic sources contribute to heavy metals in river Yamuna in monsoon and non-monsoon seasons. The health risk in terms of hazard index (HI) and fuzzy-logic hazard index (FHI) demonstrated that both HI and FHI values among children exceeded the safe limit in most of the sites in non-monsoon seasons and in few in monsoon season. For adults, HI and FHI values were within safe limit.

Comprehensive evaluation of water quality status for entire stretch of Yamuna River, India.

This study represented the first comprehensive assessment of the physicochemical water quality status of the entire Yamuna River stretch in India. The upper zone had "excellent-to-good" water quality index (WQI) with mean 5-day biochemical oxygen demand (BOD5) values of 2.1 and 2.4 mg/L during monsoon and non-monsoon, respectively. The middle region was described by "poor-to-marginal" WQI with average BOD5 values of 13.1 mg/L (monsoon) and 32.3 mg/L (non-monsoon). The low WQI observations at the midstream region were due to the negative impact of two major drains, namely Najafgarh and Shahdara, that carry partially treated effluents from industrial units. Further, BOD5 decreased to 1.9 mg/L (monsoon) and 1.8 mg/L (non-monsoon) in the lower zone, and the WQI values improved to "good" and "excellent". The dilution and depuration effects of the Chambal, Sindh, Betwa, and Ken Rivers recovered the environmental conditions in downstream stations. The oxygen sag curve complied with the water quality status along the river stretch. Based on the principal component analysis, the Yamuna River was strongly influenced by dissolved mineral salts originating from atmospheric deposition, weathering of soils and rocks, and application of deicing chemicals and landfills. Moreover, organic and nutrient substances and biological activities resulting from the discharge of sewage, and the utilization of fertilizers in agriculture, were the second contributors to pollution. The statistical techniques employed in this work could be beneficial for decision-makers (government and stakeholders) to identify the pollution sources/factors and to determine the viability of water bodies for domestic applications.

Bi-layer composite dressing of gelatin nanofibrous mat and poly vinyl alcohol hydrogel for drug delivery and wound healing application: in-vitro and in-vivo studies.

Present investigation involves the development of a bi-layer dressing of gelatin nanofibrous mat loaded with epigallocatechin gallate (EGCG)/poly vinyl alcohol (PVA) hydrogel and its in-vivo evaluation on full-thickness excision wounds in experimental Wistar rats. Nanomorphological observation, porosity, effect of crosslinking on tensile strength, physical stability and drug release profile in phosphate buffer and biocompatibility aspects of electrospun nanomat were investigated by various physico-chemical tools. EGCGa release profile was found to increase from 2-4 days with decreasing crosslinking time from 15 to 5 min. PVA hydrogels were prepared by freeze-thaw method and has been utilized as a protective and hydrating outer layer of the bi-layer dressing. Topical application of bi-layer composite dressing loaded with EGCG improve the healing rate in experimental rats as acute wounds model which was evidenced by significant increase in DNA (approximately 42%), total protein (approximately 32%), hydroxyproline (approximately 26%) and hexosamine approximately 24%) contents. A faster wound contraction was observed in wounds treated with composite dressing from approximately 14% to 47%. Histopathological examination revealed significant improvement in angiogenesis, re-epithelialization and less inflammatory response in comparison to control. Van-Gieson's collagen stains revealed matured, compact and parallel deposition of collagen fibrils on day 12. These results were supported by up-regulated expressions of matrix metalloproteinase (MMPs-2 and 9) by gelatin zymography. Control release of EGCG, 3D porous architecture of nanofibrous scaffolds as well as moist microenvironment provides ideal conditions for uninterrupted wound healing.

In vitro and in vivo efficacy of doxorubicin loaded biodegradable semi-interpenetrating hydrogel implants of poly (acrylic acid)/gelatin for post surgical tumor treatment.

The paper describes the preparation and evaluation of doxorubicin loaded semi-interpenetrating polymeric hydrogel network of polyacrylic acid (PAc) and gelatin (G). Post surgical antitumor efficacy and biodistribution of doxorubicin from the implanted degradable hydrogels was investigated on Ehrlich's ascites tumor model using albino mice. Polycaprolactone diacrylate (PCL-DAr) was employed as a crosslinking agent for PAc chains whereas G was kept free. The effect of crosslinking concentration on various physico-chemical properties such as thermal behavior, swelling, degradation behavior, drug release and polymer-polymer interactions was investigated by various physico-chemical tools. Semi-interpenetrating polymeric networks (IPNs) with 0.2 mol% crosslinking concentration showed degradation within 20 days in phosphate buffer (pH 6.5). To determine the in vivo anticancer efficacy, placebo and drug laden cylindrical implants (65 ± 5 µg/implant of 10 mg) were implanted in tumor cavity post tumor excision. After predetermined time intervals (day 7, 11, 14, 20 and 25), drug biodistribution was assessed in tumor, tumor periphery, residual hydrogel and all vital organs i.e. liver, spleen, kidney, heart, lung and blood (spectrofluorimetrically). The drug distribution study showed the concentration of drug in the tumor, tumor periphery and residual hydrogel decreased with increasing time; on the 7th day, drug concentration was highest while, on the 25th day, it was negligible; however, insignificant quantities of the drug was found in vital organs. Histological examination revealed no sign of tumor recurrence until the 25th day with 100% necrosis and slight inflammation in treated the group. In vivo results established that these biodegradable implants can be utilized as post surgical therapy for solid tumors.

Assessment of multicomponent hydrogel scaffolds of poly(acrylic acid-2-hydroxy ethyl methacrylate)/gelatin for tissue engineering applications.

The article describes the design of the multicomponent hydrogel system of poly(acrylic acid-HEMA)/gelatin for tissue engineering application. Derivative of polycaprolactone-diol (polycaprolactone diacrylate (PCL-DAr)) was used to cross-link acrylate monomers whereas gelatin was kept free for cell proliferation. Epigallocatechin gallate (EGCG), an anti-oxidant phytochemical, was loaded by diffusion method. Its in vitro release study in PBS (pH 6.5) at 37 ± 0.2°C (75 rpm) revealed a sustained release profile upto 20 days. Fitting of drug release data in Korsmeyer-Peppas model equation revealed probable release mechanism through the value of release coefficient (n), which was found to depend on formulations composition. Drug-polymer interaction, thermal behavior, and surface morphology were investigated by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, thermogravimetric analysis (TGA), and scanning electron microscopic (SEM). Swelling behavior of hydrogel in PBS (pH 6.5 and 7.4, 0.2 M) and in distilled water was found to increase with increasing AAc/HEMA ratio. Compression modulus decreased from 203 ± 3.7 KPa to 11.6 ± 1.1KPa, at 30% strain, whereas displacement values significantly increased from 3.2 ± 0.2 to 4.7 ± 0.6 mm at 20 N force (p < 0.05), with increasing AAc/HEMA ratio. Percentage cell viability was analyzed using indirect 3-[4, 5-dimethylthiazolyl-2]-2,5-diphenyltetrazo-liumbromide (MTT) assay with fibroblast L929 cells; showed ≥92.3% cell viability after 24 h incubation. Cell proliferation on the scaffold surface was found to increase with incorporation of HEMA in P(AAc)/G cross-linked hydrogel matrix upto a certain extent. These biocompatible, elastic, and swellable hydrogels can serve as a matrix for drug delivery and tissue engineering applications.

Cell adhesion and proliferation studies on semi-interpenetrating polymeric networks (semi-IPNs) of polyacrylamide and gelatin.

In this study, the effect of feed composition, degree of hydrophilicity, and internal morphology has been investigated for cell proliferation potential of the polyacrylamide/gelatin (PAm/G) semi-interpenetrating polymeric network (semi-IPNs). Polycaprolactone diacrylate was used to cross-link polyacrylamide chains. Scanning electron microscopy (SEM) micrographs demonstrate uniformly distributed porous structure with internal diameter in the range of 75-175 µm, dependent on matrix compositions. Water-air contact angle was found in the range of 49° ± 0.22 to 89° ± 0.14 (p < 0.02) suggesting varying degree of hydrophilicity of the hydrogel surface. In addition, protein adsorption study showed 45 ± 0.14 µg to 64 ± 0.12 µg (p < 0.01) of protein adsorbed per cm² of hydrogel. Quantitative estimation of cell adhesion and proliferation was carried out by DNA quantification using fluorimetric assay method (p < 0.02). Microscopic images of proliferative cells on semi-IPNs by fluorescent and inverted phase contrast supported the findings of DNA quantification. Contact angle in the range of 63-69° in association with 52-59 µg/cm² protein absorption and 115-150 µm pore size was found optimum for fibroblast proliferation on PAm/G semi-IPN scaffolds. The newly developed semi-interpenetrating network may serve as a potential scaffold for soft tissue-engineering applications.

Polycaprolactone diacrylate crosslinked biodegradable semi-interpenetrating networks of polyacrylamide and gelatin for controlled drug delivery.

A biodegradable semi-interpenetrating hydrogel network (semi-IPN) of polyacrylamide and gelatin was prepared using polycaprolactone diacrylate (mol. wt ∼ 640) as a crosslinker. The drug-polymer interaction and IPN formation were investigated by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and thermal gravimetric analysis (TGA). Scanning electron micrographs of lyophilized matrices revealed porous internal structure with varying pore sizes under equilibrium hydrated conditions, depending upon formulation composition. pH-dependent swelling and degradation was enhanced with increasing gelatin content and decreasing crosslinker concentration (Cs). Compression modulus (CM) (at 20% strain) increased significantly from 23 ± 1.4 to 75 ± 2.7 kPa (p < 0.02) with increasing Cs (from 0.5 to 2.0 mol%), while it decreased from 162 ± 6.4 to 23 ± 1.4 kPa (p < 0.05) with decreasing PAm/G ratio. Cell viability studies by MTT assay showed excellent cytocompatibility of matrices with fibroblast L929 cells. Curcumin, a hydrophobic phytochemical, was loaded by a diffusion method and its release profile was investigated in 4% w/v aqueous BSA solution at 75 rpm (at 37 ± 0.2 °C). Fitting of drug release data in the Korsmeyer-Peppas model suggested sustained release behavior up to 10 days with a combination of diffusion and erosion mechanism (0.5 < n < 1.0; M(t)/M(∞) ≤ 0.6). The newly developed porous, biodegradable and elastic semi-IPNs may serve as an ideal matrix for controlled drug release and wound healing applications. The possibilities can be explored for pharmaceutical and tissue engineering applications.