Postpolymerization Modification of Poly(2-vinyl-4,4-dimethyl azlactone) as a Versatile Strategy for Drug Conjugation and Stimuli-Responsive Release.

Postpolymerization modification of highly defined "scaffold" polymers is a promising approach for overcoming the existing limitations of controlled radical polymerization such as batch-to-batch inconsistencies, accessibility to different monomers, and compatibility with harsh synthesis conditions. Using multiple physicochemical characterization techniques, we demonstrate that poly(2-vinyl-4,4-dimethyl azlactone) (PVDMA) scaffolds can be efficiently modified with a coumarin derivative, doxorubicin, and camptothecin small molecule drugs. Subsequently, we show that coumarin-modified PVDMA has a high cellular biocompatibility and that coumarin derivatives are liberated from the polymer in the intracellular environment for cytosolic accumulation. In addition, we report the pharmacokinetics, biodistribution, and antitumor efficacy of a PVDMA-based polymer for the first time, demonstrating unique accumulation patterns based on the administration route (i.e., intravenous vs oral), efficient tumor uptake, and tumor growth inhibition in 4T1 orthotopic triple negative breast cancer (TNBC) xenografts. This work establishes the utility of PVDMA as a versatile chemical platform for producing polymer-drug conjugates with a tunable, stimuli-responsive delivery.

Protein-Functionalized Gold Nanospheres with Tunable Photothermal Efficiency for the Near-Infrared Photothermal Ablation of Biofilms.

Temperature-responsive nanostructures with high antimicrobial efficacy are attractive for therapeutic applications against multidrug-resistant bacteria. Here, we report temperature-responsive nanospheres (TRNs) engineered to undergo self-association and agglomeration above a tunable transition temperature (Tt). The temperature-responsive behavior of the nanoparticles is obtained by functionalizing citrate-capped spherical gold nanoparticles (AuNPs) with elastin-like polypeptides (ELPs). Using protein design principles, we achieve a broad range of attainable Tt values and photothermal conversion efficiencies (η). Two approaches were used to adjust this range: First, by altering the position of the cysteine residue used to attach ELP to the AuNP, we attained a Tt range from 34 to 42 °C. Then, by functionalizing the AuNP with an additional small globular protein, we could extend this range to 34-50 °C. Under near-infrared (NIR) light exposure, all TRNs exhibited reversible agglomeration. Moreover, they showed an enhanced photothermal conversion efficiency in their agglomerated state relative to the dispersed state. Despite their spherical shape, TRNs have a photothermal conversion efficiency approaching that of gold nanorods (η = 68 ± 6%), yet unlike nanorods, the synthesis of TRNs requires no cytotoxic compounds. Finally, we tested TRNs for the photothermal ablation of biofilms. Above Tt, NIR irradiation of TRNs resulted in a 10,000-fold improvement in killing efficiency compared to untreated controls (p < 0.0001). Below Tt, no enhanced antibiofilm effect was observed. In conclusion, engineering the interactions between proteins and nanoparticles enables the tunable control of TRNs, resulting in a novel antibiofilm nanomaterial with low cytotoxicity.

Near-Infrared Photothermal Ablation of Biofilms using ProteinFunctionalized Gold Nanospheres with a Tunable Temperature Response.

Temperature-responsive nanostructures with high antimicrobial efficacy are attractive for therapeutic applications against multi-drug-resistant bacteria. Here, we report temperature-responsive nanospheres (TRNs) that are engineered to undergo self-association and agglomeration above a tunable transition temperature (Tt). Temperature-responsive behavior of the nanoparticles is obtained by functionalizing citrate-capped, spherical gold nanoparticles (AuNPs) with elastin-like polypeptides (ELPs). Using protein design principles, we achieve a broad range of attainable Tt values and photothermal conversion efficiencies (η). Two approaches were used to adjust this range: First, by altering the position of the cysteine residue used to attach ELP to the AuNP, we attained a Tt range from 34-42 °C. Then, functionalizing the AuNP with an additional small globular protein, we were able to extend this range to 34-50 °C. Under near-infrared (NIR) light exposure, all TRNs exhibited reversible agglomeration. Moreover, they showed enhanced photothermal conversion efficiency in their agglomerated state relative to the dispersed state. Despite their spherical shape, TRNs have a photothermal conversion efficiency approaching that of gold nanorods (η = 68±6%), yet unlike nanorods, the synthesis of TRNs requires no cytotoxic compounds. Finally, we tested TRNs for photothermal ablation of biofilms. Above Tt, NIR irradiation of TRNs resulted in a 10,000-fold improvement in killing efficiency compared to untreated controls (p < 0.0001). Below Tt, no enhanced anti-biofilm effect was observed. In conclusion, engineering the interactions between proteins and nanoparticles enables the tunable control of TRNs, resulting in a novel, anti-biofilm nanomaterial with low cytotoxicity.

Role of high-fat diet on letrozole-induced polycystic ovarian syndrome in rats.

Polycystic ovary syndrome (PCOS) is one of the most prevalent hormonal disorders in women of reproductive age. Letrozole (LET)-induced PCOS is a good model but has drawbacks such as the absence of metabolic changes. Hence, in the present study, we aimed to develop a new animal model combining a high-fat diet (HFD) and LET. Female Wistar rats were divided into a control group, LET group, and LET + HFD (45% energy from fat) group. Compared with the control group, the LET and LET + HFD groups showed ovarian cysts and elevated testosterone levels, whereas oestradiol and progesterone levels were reduced. The LET + HFD group displayed significant changes in body weight, as well as in levels of triglycerides, fasting blood glucose, direct bilirubin, alanine aminotransferase, and uric acid; in terms of glucose intolerance and insulin resistance, the LET + HFD group showed better results than the LET group. Compared with the control group, elevated levels of tumour necrosis factor-α were detected in both the LET and LET + HFD groups. The addition of HFD to the LET model afforded good metabolic aberrations, along with ovarian cysts. In contrast, the LET-only model failed to demonstrate metabolic anomalies observed in the human PCOS condition.

Application and Comparative Evaluation of Fluorescent Antibody, Immunohistochemistry and Reverse Transcription Polymerase Chain Reaction Tests for the Detection of Rabies Virus Antigen or Nucleic Acid in Brain Samples of Animals Suspected of Rabies in India.

Accurate and early diagnosis of animal rabies is critical for undertaking public health measures. Whereas the direct fluorescent antibody (DFA) technique is the recommended test, the more convenient, direct rapid immunochemistry test (dRIT), as well as the more sensitive, reverse transcription polymerase chain reaction (RT-PCR), have recently been employed for the laboratory diagnosis of rabies. We compared the three methods on brain samples from domestic (dog, cat, cattle, buffalo, horse, pig and goat) and wild (leopard, wolf and jackal) animals from various parts of India. Of the 257 samples tested, 167 were positive by all the three tests; in addition, 35 of the 36 decomposed samples were positive by RT-PCR. This is the first study in which such large number of animal samples have been subjected to the three tests simultaneously. The results confirm 100% corroboration between DFA and dRIT, buttress the applicability of dRIT in the simple and rapid diagnosis of rabies in animals, and reaffirm the suitability of RT-PCR for samples unfit for testing either by DFA or dRIT.

Limit of detection of genomic DNA by conventional PCR for estimating the load of Staphylococcus aureus and Escherichia coli associated with bovine mastitis.

Detection of mastitis-associated bacteria can be accomplished by culturing or by molecular techniques. On the other hand, rapid and inexpensive methods to enumerate bacterial load without culturing can be better achieved by molecular methods. Staphylococcus aureus and Escherichia coli are the predominant bacterial pathogens associated with bovine mastitis. Here, we describe the application of conventional PCR for the limit of detection (LOD) of genomic DNA of S. aureus and E. coli based on single-copy genes. The selected genes were thermonuclease (nuc), aureolysin (aur), and staphopain A (scpA) for S. aureus and ß-D-glucuronidase A (uidA), cytochrome d oxidase (cyd), and rodA (a gene affecting cell shape and methicillin sensitivity) for E. coli. The LOD was 5.3, 15.9, and 143 pg for aur, nuc, and scpA genes, corresponding to S. aureus genomic copies of 1.75 × 10(3), 5.16 × 10(3), and 4.71 × 10(4), respectively. The LOD was 0.45, 12.3 and 109 pg for uidA, rodA and cyd genes, corresponding to E. coli genome copies of 8.91 × 10(1), 2.43 × 10(3), and 2.16 × 10(4), respectively. Application of uidA and aur PCRs to field strains revealed that as low as approximately 100 genome copies of E. coli and 1000-10,000 copies of S. aureus could be detected. This study is the first to report LOD of genomic DNA using conventional PCR for aur and scpA genes of S. aureus, and rodA and cyd genes of E. coli. The results should be useful for developing assays to assess bacterial load in milk and to determine the load that contributes to subclinical or clinical mastitis.

Ameliorating effect of piperine on behavioral abnormalities and oxidative markers in sodium valproate induced autism in BALB/C mice.

Post natal exposure to VPA (valproic acid) in mice induces behavioral deficits, abnormal sensitivity to sensory stimuli and self-injurious behavior, observed in autism. Piperine has been reported to have protective effect on brain. The present study aimed at evaluating effect of piperine on VPA induced neurobehavioral and biochemical alterations in BALB/c mice. Young BALB/c mice 13 days old were procured from five different litters and segregated into five groups (n=6; 3 male, 3 female) i.e., Group I served as control group, received physiological saline on PND (Post natal day) 14 & Tween 80 p.o. from PND13-40. Group II served as normal treated group and received piperine (20mg/kg p.o.) from PND 13-40 and saline s.c. on PND 14. Group III served as valproate treated group received VPA (400mg/kg s.c.) on PND 14 and Tween 80 p.o. from PND 13-40. Group IV & V served as disease treated group received VPA (400mg/kg s.c.) on PND 14 & piperine (5 & 20mg/kg p.o.) from PND 13-40 respectively. BALB/c mice pups were subjected to behavioral testing to assess motor skill development, nociceptive response, locomotion, anxiety, and cognition on various postnatal days up to PND 40. At the end of behavioral evaluation, mice were sacrificed; brain was isolated for biochemical estimations (serotonin, glutathione, MDA and nitric oxide) and histopathological examination. Our study revealed that treatment with piperine significantly improved behavioral alterations, lowered oxidative stress markers, and restored histoarchitecture of cerebellum. This ameliorating effect of piperine is attributed to its anti-oxidant activity, cognition enhancing and neuroprotective activity.

Protective effect of lawsone on L-Arginine induced acute pancreatitis in rats.

The efficacy of lawsone against L-arginine induced acute pancreatitis was determined at 24 h by determination of serum levels of amylase, lipase and proinflammatory cytokines [tumor necrosis factor (TNF)-alpha, C-reactive proteins and interleukin (IL)], pancreatic myeloperoxidase (MPO) activity, lipid peroxidation (thiobarbituric acid reactive substances (TBARS)], nitrate/nitrite levels, and the wet weight/body weight ratio. Lawsone and methylprednisolone treatments significantly attenuated the L-arginine- induced increases in pancreatic wet weight/body weight ratio, and decreased the serum levels of amylase and lipase, and TNF-alpha and IL-6 and significantly lowered pancreatic levels of MPO, TBARS, and nitrate/nitrite. The histoimmunological findings further proved the amelioration of pancreatic injury by lawsone and further proved anti-inflammatory and antioxidant agent property of lawsone.

Synthesis, anticonvulsant, antioxidant and binding interaction of novel N-substituted methylquinazoline-2,4(1H,3H)-dione derivatives to bovine serum albumin: a structure-activity relationship study.

A novel class of N-substituted glycosmicine derivatives was synthesized, and their anticonvulsant, antioxidant activity and interaction with bovine serum albumin (BSA) were evaluated. The synthesized compounds 4a-j were examined for anticonvulsant activity by maximal electroshock induced seizures (MESs) test and their neurotoxic effects were determined by rotorod test in mice. The structure-activity relationships (SARs) of these compounds were also investigated. Compounds 4d, 4g, 4i and 4j were found to have good protective effect from seizure. The in vitro antioxidant activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radical scavenging assay. The interaction between novel N-substituted methylquinazoline-2,4(1H,3H)-dione (NMQ) and BSA was analyzed by fluorescence and ultraviolet spectroscopy at 304K under simulative physiological conditions. BSA fluorescence quenched by NMQ is discussed according to the Stern-Volmer equation. The binding constant and binding sites of NMQ with BSA were calculated. According to Forster non-radiation energy transfer theory, the binding distance (r) between NMQ and BSA was calculated.

Protective effect of 2-hydroxy-4-methoxy benzoic acid on testosterone induced benign prostatic hyperplasia in Wister rats.

Oxidative stress is one of the major causative factors for development of benign prostatic hyperplasia (BPH). The aim of the present study is to evaluate the effect of 2-hydroxy-4-methoxy benzoic acid (HMBA), a potential antioxidant on testosterone induced BPH in rats. Male Wistar rats were divided into five groups (n=6), Group I--received saline, Group II--received testosterone (3mg/kg/s.c.), Group III-received testosterone+finasteride (5mg/kg/oral), Group IV and V received testosterone+HMBA (200 and 400 µg/kg/i.p.), respectively, for 21 days. Animals were weighed before and after the study period. On 22nd day, animals were humanly killed by cervical dislocation. Prostates were excised and weighed, and used for biochemical and histological studies. As a result, testosterone treated rats showed increased prostate weight; prostatic index accompanied with depleted antioxidant enzymes levels, elevated lipid peroxides and total nitrite and associated histology disruption. HMBA treatment at 200 µg/kg/i.p. and 400 µg/kg/i.p. significantly restored (P<0.05) antioxidant enzyme levels, lipid peroxide and total nitrite when compared to disease control animals. It also ameliorated the testosterone induced histological changes. The present study suggests the protective role of HMBA on testosterone induced BPH by virtue of its antioxidant potential.

Synthesis, characterization, antidepressant and antioxidant activity of novel piperamides bearing piperidine and piperazine analogues.

A series of piperamide derivatives (8a-j) was synthesized with various substituted piperidine and piperazine compounds. The prepared compounds were evaluated for antibacterial activity against gram-positive and gram-negative bacteria and antifungal activity by disc diffusion method. The antioxidant activity of the compounds was evaluated by DPPH and superoxide radical scavenging method and antidepressant activity using forced swim and tail suspension behavioral despair tests in mice. The compounds 8a, 8b and 8c were investigated for their monoamine oxidase A and B (MAO-A and MAO-B) inhibitory property. Some of the test compounds were active in forced swim test (FST) and tail suspension test (TST). Compounds 8a and 8b showed a significant effect, when compared to standard drug, clorgyline.

Bacopa monniera (L.) Wettst ameliorates behavioral alterations and oxidative markers in sodium valproate induced autism in rats.

Early prenatal or post natal exposure to environmental insults such as valproic acid (VPA), thalidomide and ethanol could induce behavioral alterations similar to autistic symptoms. Bacopa monniera, a renowned plant in ayurvedic medicine is useful in several neurological disorders. The purpose of the present study was to evaluate the effect of B. monniera on VPA induced autism. On 12.5 day of gestation the female pregnant rats were divided into control and VPA treated groups. They were administered saline/VPA (600 mg/kg, i.p.) respectively and allowed to raise their own litters. Group I-male pups of saline treated mothers. On postnatal day (PND) 21 VPA induced autistic male pups were divided into two groups (n = 6); Group II-received saline and Group III-received B. monniera (300 mg/kg/p.o.) from PND 21-35. Behavioral tests (nociception, locomotor activity, exploratory activity, anxiety and social behavior) were performed in both adolescence (PND 30-40) and adulthood (PND 90-110) period. At the end of behavioral testing animals were sacrificed, brain was isolated for biochemical estimations (serotonin, glutathione, catalase and nitric oxide) and histopathological examination. Induction of autism significantly affected normal behavior, increased oxidative stress and serotonin level, altered histoarchitecture of cerebellum (decreased number of purkinje cells, neuronal degeneration and chromatolysis) when compared with normal control group. Treatment with B. monniera significantly (p < 0.05) improved behavioral alterations, decreased oxidative stress markers and restored histoarchitecture of cerebellum. In conclusion, the present study suggests that B. monniera ameliorates the autistic symptoms possibly due to its anti-anxiety, antioxidant and neuro-protective activity.

Lauric acid and myristic acid prevent testosterone induced prostatic hyperplasia in rats.

Numerous plants have proven to improve uncontrolled growth of the prostate gland and improve urinary tract symptoms associated with benign prostatic hyperplasia. Major components of those plants were lauric acid and myristic acid. Our study investigated whether lauric acid or myristic acid prevent testosterone induced prostatic hyperplasia in rats. Rats were divided into negative control and testosterone induced prostatic hyperplasia rats (positive control, low dose lauric acid treated, high dose lauric acid treated, low dose of myristic acid treated, high dose of myristic acid treated, finasteride treated). Testosterone and drug treatment were carried out for 14 days. Body weights were recorded before and after treatment. On 15th day, rats were sacrificed, prostates were weighed and histopathological studies were carried out. Lauric acid/myristic acid treatment showed significant inhibition of prostate enlargement and protection of histoarchitecture of prostate when compared with positive control group. In conclusion, the study showed that lauric acid/myristic acid reduced the increase of both prostate weight and prostate weight:body weight ratio, markers of testosterone induced prostatic hyperplasia in rats.

Involvement of nitric oxide in 5-HT(3) receptor agonist-induced fluid accumulation in jejunum and colon of anesthetized rats.

OBJECTIVES: The aim of the present study was to investigate the involvement of nitric oxide in 5-HT(3) receptor agonist-induced fluid accumulation in jejunum and colon of anesthetized rats. MATERIALS AND METHODS: Fluid movement in jejunum and colon were determined simultaneously in the same rat, by modifying the Beubler method. Nomega-nitro-L-arginine (L-NNA, 20 mg/kg, s.c) alone and in combination with L-arginine (L-Arg, 150 mg/kg s.c) or D-arginine (D-Arg, 150 mg/kg, s.c) were administered 30 min before administration of 1-PBG (18.5 mug/kg, i.v). RESULTS: Intravenous administration of 1-phenylbiguanide (1-PBG) induced a net secretion of fluid in both jejunum and colon. 1-PBG had a more prominent secretory effect in the colon, causing a three-fold increase in volume of fluid secreted/g of colon than in the jejunum. Pretreatment with (L-NNA) prevented the 1-PBG-induced fluid accumulation in both jejunum and colon. The inhibitory effect of L-NNA on 1-PBG-induced fluid accumulation was reversed by L-Arg but not by D-Arg. CONCLUSION: These results provide evidence that nitric oxide plays an important role in 5-HT(3) receptor agonist-induced fluid accumulation in jejunum and colon of anesthetized rats.