Bacterial cellulose matrix with in situ impregnation of silver nanoparticles via catecholic redox chemistry for third degree burn wound healing.

In the present study, bacterial cellulose (BC) based nanocomposite dressing material was developed for third burn wound management by polydopamine (PD) coated BC with in situ reduction of silver nanoparticles (BC-PDAg). BC-PDAg nanocomposite was characterized to understand the morphological, physical and chemical properties. Antimicrobial activity of BC-PDAg against burn wound specific pathogens were significant. The in vitro cytotoxicity and proliferation studies revealed that BC-PDAg nanocomposite is biocompatible and it supports cell proliferation. Further, in vivo experiments on female albino Wistar rats confirmed that BC-PDAg was effective in wound healing by promoting re-epithelization, and collagen deposition as evidenced by histopathological analysis. Moreover, molecular gene expression study has revealed that BC-PDAg promotes healing process by regulating the expression of inflammatory, angiogenesis and growth factor genes. The overall performance of BC-PDAg nanocomposite suggests that it could be used as promising skin regenerative tool in modern medicine.

Pyriproxyfen induced impairment of reproductive endocrine homeostasis and gonadal histopathology in zebrafish (Danio rerio) by altered expression of hypothalamus-pituitary-gonadal (HPG) axis genes.

Pyriproxyfen (PPF), a broad-spectrum insecticide known to cause reproductive and endocrine disruption in invertebrates, while the data is scarce in aquatic vertebrates. The goal of this study is to investigate the impact of PPF on reproductive endocrine system of male and female zebrafish along hypothalamus-pituitary-gonadal (HPG) axis. In brain, PPF caused significant alteration in the transcripts of erα, lhß, and cyp19b genes in male and fshß, lhß, and cyp19b genes in female zebrafish. The downstream genes of steroidogenic pathway like, star, 3ßhsd, 17ßhsd, and cyp19a expression were significantly altered in gonad of both sexes. Subsequent changes in circulatory steroid hormone levels lead to imbalance in hormone homeostasis as revealed from estradiol/testosterone (E2/T) ratio. Further, the vitellogenin transcript level was enhanced in hepatic tissues and their blood plasma content was increased in male (16.21%) and declined in female (21.69%). PPF also induced histopathological changes in gonads such as, reduction of mature spermatocytes in male and vitellogenic oocytes in female zebrafish. The altered E2/T ratio and gonadal histopathology were supported by the altered transcript levels of HPG axis genes. Overall, these findings provide new insights of PPF in zebrafish reproductive system and highlights for further investigations on its potential risks in aquatic environment.

Thymol enriched bacterial cellulose hydrogel as effective material for third degree burn wound repair.

Bacterial cellulose is well known for its excellent contributions in biomedical applications due to its superior properties. However the lack of antimicrobial property restricts its use in wound healing. To address the complications in third degree burns, thymol enriched bacterial cellulose hydrogel (BCT) was developed in this study. The incorporation of thymol into bacterial cellulose along with its chemical and thermal changes were investigated by FTIR, TGA and DSC respectively. Antimicrobial studies revealed that BCT possess excellent biocidal activity against burn specific pathogens. The in vitro biocompatibility studies were carried out in mouse 3T3 fibroblast cells. The BCT hydrogel facilitated the growth of fibroblast cells, exhibiting low toxicity, and increased cell viability. The burn wound healing efficiency of the BCT hydrogel was examined in vivo using female albino Wistar rats. Histopathological studies reveal that the wound treated with BCT hydrogel showed faster wound closure than BC and control groups. All these findings, suggest that BCT hydrogel can be used as resourceful and natural burn wound dressing material.