Poly(2-alkenyl-2-oxazoline)s are promising functional polymers for a variety of biomedical applications, such as drug delivery systems, peptide conjugates, or gene delivery. In this study, poly(2-isopropenyl-2-oxazoline) (PIPOx) is prepared through free-radical polymerization initiated with azobisisobutyronitrile. Reactive 2-oxazoline units in the side chain support an addition reaction with different compounds containing a carboxylic group, which facilitates the preparation of polymers labeled with two different fluorescent dyes. The cytotoxicities of 2-oxazoline monomers, PIPOx, and fluorescently labeled PIPOx are evaluated in vitro using an 3-(4,5-Dimethyldiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and ex vivo using a cell proliferation assay with adenosine triphosphate bioluminescence. The cell uptake of labeled PIPOx is used to determine the colocalization of PIPOx with cell organelles that are part of the endocytic pathway. For the first time, it is shown that poly(2-isopropenyl-2-oxazoline) is a biocompatible material and is suitable for biomedical applications; further, its immunomodulative properties are evaluated.

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Chitosan-Silver nanocomposites (CS-HDA-AgNCs) was prepared using chitosan (CS), biogenic silver nanocomposites (AgNCs) and cross-linker, hexamethylene 1, 6-di (amino carboxysulfonate) (HDA). The film is flexible and transparent. Its physical, mechanical, thermal, hydrophilicity and swelling properties were improved by HDA (2.5%). The antimicrobial activity of CS-HDA-AgNCs were not displayed any remarkable zone of inhibition but shows toxic effect in presence of normal 3T3 fibroblasts and cancer HeLa cells. It decreases to ca. 5-7 % for both cell lines. In conclusion, it can be mentioned that the CS-HDA-AgNCs, a kind of new functional biomaterial which could be useful for healthcare applications.

Bioreduction of silver ions following one pot process is described to achieveRheum rhabarbarum(RR) based silver nanoparticles (SNPs) which is termed as “RR-SNPs.” The Ultraviolet–visible spectroscopy (UV–vis) confirms the characteristic surface plasmon resonance band for RR-SNPs in the range of 420–460 nm. The crystalline nature of SNPs was confirmed by X-ray diffraction (XRD) peaks at 38.2°, 45.6°, 64.2°, and 76.8°. Transmission electron microscopy (TEM) and scanning electronic microscopy (SEM) confirm the shape of synthesized SNPs. They are roughly spherical but uniformly distributed, and size varies from 60 to 80 nm. These biogenic SNPs show persistent zeta potential value of 34.8 mV even after 120 days and exhibit potent antibacterial activity in presence ofEscherichia coli(CCM 4517) andStaphylococcus aureus(CCM 4516). In addition, cytotoxicity of RR-SNPs againstin vitrohuman epithelial carcinoma (HeLa) cell line showed a dose-response activity. The lethal concentration (LC50) value was found to be 28.5 μg/mL for RR-SNPs in the presence of HeLa cells. These findings help us to evaluate their appropriate applications in the field of nanotechnology and nanomedicine.

In an effort to produce non-toxic and economically viable “green” protocols for waste water treatment, researchers are actively involved to develop versatile and effective silver nanoparticles (SNPs) as nano-catalyst from bio-based techniques. Since, p-nitrophenol (PNP) is one of the anthropogenic contaminants, considerable attention has been focused in catalytic degradability of PNP in wastewater treatment by curtailing serious effect on aquatic fauna. Ingestion of contaminants by aquatic organisms will not only affect the aquatic species but is also a potential threat to human health, especially if the toxic contaminants are involved in food chain. In this short report, we provided a comprehensive insight on few remarkable nanocatalysts especially based on SNPs and its biopolymer composites synthesized via ecofriendly “green” route. The beneficiality and catalytic performance of these silver nanocatalysts are concisely documented on standard model degradation reduction of PNP to p-aminophenol (PAP) in the presence of aqueous sodium borohydride. The catalytic degradation of PNP to PAP using SNPs follows pseudo first order kinetics involving six-electrons with lower activation energy. Furthermore, we provided a list of highly effective, recoverable, and economically viable SNPs, which demonstrated its potential as nanocatalysts by focusing its technical impact in the area of water remediation.

The current report was intended towards comparative study of green-synthesized biogenic Rhubarb silver nanoparticles (RS-AgNPs) and chitosan crosslinked silver nanocomposites (CSHD-AgNCs). The physico-chemical characterization was done by UV-visible, FTIR, scanning electron microscopy (SEM), transmission electron microscopy (TEM), EDX, TGA, XRD and zeta potential (ζ). The analysis and spectroscopic characterization was done by SEM and TEM and their results reveal that the nanoparticles are spherical in shape, with average size ranges from 5 to 50 nm, and was gathered by face centered cubic (FCC) structure throughout the polymer matrix and stable without any protecting or capping reagents over 450 days. The antimicrobial property of RS-AgNPs and CSHD-AgNCs (ζ = +29.6 and +32.8 mV) was evaluated against E. coli and S. aureus and showed an effective inhibitory property. The RS-AgNPs and CSHD-AgNCs were assessed for their anticancer activity against HeLa cell line by MTT method, and it reveals a dose-response activity, time and cell line-dependent cytotoxicity. Based on the results obtained, the RS-AgNPs exhibited higher toxicity over CSHD-AgNCs after 24 h incubation of HeLa cells with different concentrations and is negligible for the aqueous Rhubarb extract. It was concluded that the changes in anticancer activity towards HeLa cells due to biological activity of silver nanoparticles depend on their method of biosynthesis and their physico-chemical nature.

Background A simple and simultaneous electrochemical sensing platform was fabricated by electropolymerization of allura red on glassy carbon electrode (GCE) for the interference-free detection of dihydroxy benzene isomers. Methods The modified working electrode was characterized by electrochemical and field emission scanning electron microscopy methods. The modified electrode showed excellent electrocatalytic activity for the electrooxidation of catechol (CC) and hydroquinone (HQ) at physiological pH of 7.4 by cyclic voltammetric (CV) and differential pulse voltammetric (DPV) techniques. Results The effective split in the overlapped oxidation signal of CC and HQ was achieved in a binary mixture with peak to peak separation of 0.102 V and 0.103 V by CV and DPV techniques. The electrode kinetics was found to be adsorption-controlled. The oxidation potential directly depends on the pH of the buffer solution, and it witnessed the transfer of equal number of protons and electrons in the redox phenomenon. Conclusions The limit of detection (LOD) for CC and HQ was calculated to be 0.126 μM and 0.132 μM in the linear range of 0 to 80.0 μM and 0 to 110.0 μM, respectively, by ultra-sensitive DPV technique. The practical applicability of the proposed sensor was evaluated for tap water sample analysis, and good recovery rates were observed. Graphical abstract Electrocatalytic interaction of ALR/GCE with dihydroxy benzene isomers.

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