Ag2[Fe(CN)5NO]-Fabricated Hydrophobic Cotton as a Potential Wound Healing Dressing: An In Vivo Approach.

There have been reports of different types of wound dressings for various functions and purposes. Cotton being one of the most widely used wound dressing material due to its non-toxic, biodegradable, and other properties is used for fabrication as well as in the form of scaffolds for faster and effective wound closure. Our research team has already demonstrated the role of silver nitroprusside nanoparticles (SNPNPs) for wound healing and antibacterial activity. In the current study, we have developed cotton fabric impregnated with SNPNPs (SNPCFs) which remain photo inert and displayed long-term antimicrobial activity due to the surface modification with the silver nitroprusside complex. These SNPCFs were characterized by various analytical techniques (XRD, FTIR, UV spectroscopy, TGA, TEM, FESEM, EDAX, ICP-OES). The fabricated cotton dressings with nanoparticles showed an improved water contact angle (113-130°) than that of bare cotton gauze (60°) and exhibited more antibacterial property in case of both Gram-negative bacteria (Klebsiella aerogenes and Escherichia coli) and Gram-positive bacteria (Pseudomonas aeruginosa and Bacillus subtilis) even after several washings. The biocompatible nature of SNPCFs was assessed by in vivo chorioallantoic membrane assay that showed no obstruction in the formation of blood vessels. The SNPCFs exhibited better wound healing activity compared to the bare cotton and AgCFs as observed in the C57BL6/J mouse. The histopathological investigation reveals increase in re-epithelialization and deposition of connective tissue. The macrophage (M2) counts in SNPCF-treated skin tissues were supportive of more wound healing activity than mice treated with cotton fabric impregnated with chemically synthesized silver nanoparticles. Based on biodistribution analysis using ICP-OES, the data illustrated that a significant amount of silver is absorbed in the skin tissues of mice as compared to the blood and kidney. Furthermore, the absence of silver from the vital organs (heart, liver, and kidney) corroborates our hypothesis that the SNPCFs can act excellently in treating wounds when topically applied over skin. Thereafter, all these results highlight a strong possibility that SNPCFs exemplify the potential as a new antimicrobial and wound healing agent in future times.

Green Synthesis and Characterization of Monodispersed Gold Nanoparticles: Toxicity Study, Delivery of Doxorubicin and Its Bio-Distribution in Mouse Model.

In the present article, we report the in vitro and in vivo delivery of doxorubicin using biosynthesized gold nanoparticles (b-Au-PP). Gold nanoparticles were synthesized by a simple, fast, efficient, environmentally friendly and economical green chemistry approach using an extract of Peltophorum pterocarpum (PP) leaves. Because the biosynthesized b-Au-PP was highly stable in various physiological buffers for several weeks and biocompatible in both in vitro and in vivo systems, we designed and developed a biosynthesized gold nanoparticle (b-Au-PP)-based drug-delivery system (DDS) using doxorubicin (Dox) (b-Au-PP-Dox). Both b-Au-PP and b-Au-PP-Dox were thoroughly characterized using several analytical tools. Administration of doxorubicin-loaded DDS (b-Au-PP-Dox) resulted in a significant inhibition of the proliferation of cancer cells (A549, B16F10) in vitro and of tumor growth in an in vivo model compared to doxorubicin alone. Furthermore, we found that the cellular uptake and release of Dox in the nanoconjugated form (b-Au-PP-Dox) were faster than the uptake and release of unconjugated Dox. The in vivo toxicity study did not show any significant changes in the hematology, serum clinical biochemistry or histopathology in the C57BL6/J female mice after consecutive intraperitoneal (IP) injections over a period of seven days. To the best of our knowledge, our study is the first to report the application of a biosynthesized gold nanoparticle-based DDS for cancer therapy in an animal model, in addition to a detailed in vivo toxicity study. Together, the results demonstrate that a biosynthesized gold nanoparticle-based drug-delivery system (b-Au-PP-Dox) could be used in the near future as an alternative cost-effective treatment strategy for cancer therapy.

Curcumin loaded mesoporous silica: an effective drug delivery system for cancer treatment.

In the present study, we report the delivery of anti-cancer drug curcumin to cancer cells using mesoporous silica materials. A series of mesoporous silica material based drug delivery systems (S2, S4 and S6) were first designed and developed through the amine functionalization of KIT-6, MSU-2 and MCM-41 followed by the loading of curcumin. The curcumin loaded materials were characterized with several physico-chemical techniques and thoroughly screened on cancer cells to evaluate their in vitro drug delivery efficacy. All the curcumin loaded silica materials exhibited higher cellular uptake and inhibition of cancer cell viability compared to pristine curcumin. The effective internalization of curcumin in cancer cells through the mesoporous silica materials initiated the generation of intracellular reactive oxygen species and the down regulation of poly ADP ribose polymerase (PARP) enzyme levels compared to free curcumin leading to the activation of apoptosis. This study shows that the anti-cancer activity of curcumin can be potentiated by loading onto mesoporous silica materials. Therefore, we strongly believe that mesoporous silica based curcumin loaded drug delivery systems may have future potential applications for the treatment of cancers.

Green synthesis, characterization of gold and silver nanoparticles and their potential application for cancer therapeutics.

In the present article, we demonstrate the delivery of anti-cancer drug to the cancer cells using biosynthesized gold and silver nanoparticles (b-AuNP & b-AgNP). The nanoparticles synthesized by using Butea monosperma (BM) leaf extract are thoroughly characterized by various analytical techniques. Both b-AuNP and b-AgNP are stable in biological buffers and biocompatible towards normal endothelial cells (HUVEC, ECV-304) as well as cancer cell lines (B16F10, MCF-7, HNGC2 & A549). Administration of nanoparticle based drug delivery systems (DDSs) using doxorubicin (DOX) [b-Au-500-DOX and b-Ag-750-DOX] shows significant inhibition of cancer cell proliferation (B16F10, MCF-7) compared to pristine drug. Therefore, we strongly believe that biosynthesized nanoparticles will be useful for the development of cancer therapy using nanomedicine approach in near future.

A green chemistry approach for the synthesis of gold nanoconjugates that induce the inhibition of cancer cell proliferation through induction of oxidative stress and their in vivo toxicity study.

In this paper, we report the synthesis of gold nanoconjugates (b-Au-LM) using the aqueous leaf extract of Lantana montevidensis (LM), a naturally available medicinal plant. The biosynthesized b-Au-LM was biocompatible in both in vitro and in vivo systems. However, the LM extract as well as b-Au-LM exhibited significant inhibition of the proliferation of cancer cells. Interestingly, b-Au-LM showed enhanced anti-cancer activity compared to the pristine LM extract. Generation of reactive oxygen species (ROS) and oxidative stress, which triggered the upregulation of caspase-3, might be the plausible reason for anti-cancer activity. Cell cycle analysis demonstrated G2/M (in A549 cells) or Sub-G1 (in MCF-7) cell cycle arrest, which might lead to apoptosis. Together, the results support the future therapeutic application of an in situ biosynthesized gold nanoconjugates based drug delivery system (b-Au-LM) towards cancer therapy and other biomedical applications.

Bioconjugated gold nanoparticles accelerate the growth of new blood vessels through redox signaling.

We have designed and developed novel pro-angiogenic bio-synthesized gold nanoconjugates (b-Au-HP) that make new blood vessels, as observed by several in vitro and in vivo assays, suggesting their future potential applications in alternative treatment strategies for wound healing, cardiovascular diseases (CVD) and ischemic diseases using a nanomedicine approach.

Green chemistry approach for the synthesis and stabilization of biocompatible gold nanoparticles and their potential applications in cancer therapy.

The biological approach to synthesis of AuNPs is eco-friendly and an ideal method to develop environmentally sustainable nanoparticles alternative to existing methods. We have developed a simple, fast, clean, efficient, low-cost and eco-friendly single-step green chemistry approach for the synthesis of biocompatible gold nanoparticles (AuNPs) from chloroauric acid (HAuCl(4)) using a water extract of Eclipta Alba leaves at room temperature. The AuNPs using Eclipta extract have been formed in very short time, even in less than 10 min. The as-synthesized AuNPs were thoroughly characterized by several physico-chemical techniques. The in vitro stability of as-synthesized AuNPs was studied in different buffer solutions. A plausible mechanism for the synthesis of AuNPs by Eclipta extract has been discussed. The biocompatibility of AuNPs was observed by in vitro cell culture assays. Finally, we have designed and developed a AuNPs-based drug delivery system (DDS) (Au-DOX) containing doxorubicin (DOX), a FDA approved anticancer drug. Administration of this DDS to breast cancer cells (MCF-7 and MDA-MB-231) shows significant inhibition of breast cancer cell proliferation compared to pristine doxorubicin. Therefore we strongly believe that the use of Eclipta Alba offers large-scale production of biocompatible AuNPs that can be used as a delivery vehicle for the treatment of cancer diseases.

Noninvasive radiofrequency field-induced hyperthermic cytotoxicity in human cancer cells using cetuximab-targeted gold nanoparticles.

Shortwave (MHz range) radiofrequency (RF) energy is nonionizing, penetrates deeply into biologic tissues with no adverse side effects, and heats gold nanoparticles efficiently. Targeted delivery of gold nanoparticles to cancer cells should result in hyperthermic cytotoxicity upon exposure to a focused, noninvasive RF field. In this report we demonstrate that gold nanoparticles conjugated with cetuximab (C225) are quickly internalized by Panc-1 (pancreatic adenocarcinoma) and Difi (colorectal adenocarcinoma) cancer cells overexpressing epidermal growth factor receptor (EGFR). Panc-1 or Difi cells treated with naked gold nanoparticles or nonspecific IgG-conjugated gold nanoparticles demonstrated minimal intracellular uptake of gold nanoparticles by transmission electron microscopy (TEM). In contrast, there were dense concentrations of cytoplasmic vesicles containing gold nanoparticles following treatment with cetuximab-conjugated gold nanoparticles. Exposure of cells to a noninvasive RF field produced nearly 100% cytotoxicity in cells treated with the cetuximab-conjugated gold nanoparticles, but significantly lower levels of cytotoxicity in the two control groups (P < 0.00012). Treatment of a breast cancer cell line (CAMA-1) that does not express EGFR with cetuximab-conjugated gold nanoparticles produced no enhanced cytotoxicity following treatment in the RF field. Conjugation of cancer cell-directed targeting agents to gold nanoparticles may represent an effective and cancer-specific therapy to treat numerous types of human malignant disease using noninvasive RF hyperthermia.