Waste derived approach towards wealthy fluorescent N-doped graphene quantum dots for cell imaging and H2O2 sensing applications.

Herein, we report the synthesis of a highly fluorescent nitrogen doped graphene quantum dots (N-GQDs) from waste precursors such as melamine sponge and arjuna bark via a microwave treatment and its functional and morphological characterization using various spectroscopy techniques such as optical, FTIR, XPS and TEM. The as-prepared aqueous N-GQD (dia. 2-3 nm) was used for the bio-imaging application using breast carcinoma cell line (MDA-MB-231) as a model, and the locations of all cells in the cytoplasm as well as nuclei were observed to stain brightly in blue fluorescent color successfully. In addition to that, the aqueous N-GQD showed fluorescence quenching behavior in the presence of hydrogen peroxide, which was exploited to sense H2O2, a probable toxin generated in the diseased cells. Importantly, the cell cytotoxicity was measured and found to be non-toxic (70% survival) to the MDA-MB-231 cells even at very high concentration (∼1.8 mg/ml) of the synthesized N-GQD. This study revealing excellent biocompatibility and imaging of the model cancer cells, and sensing of H2O2 by fluorescent quenching, indicates potential in-vivo cell culture applications of the prepared fluorescent N-GQD.

Trimethyl chitosan coated palladium nanoparticles as a photothermal agent and its in vitro evaluation in 2D and 3D model of breast cancer cells.

The potential of palladium has been scantily explored in biomedical applications. In the present study, palladium nanoparticles (PdNPs) were synthesized and were successfully coated with trimethyl-chitosan (TMC) to improve their biocompatibility. Coating with TMC improved the nanoparticle accumulation in MDAMB231 breast cancer cells, compared to nanoparticles coated with native chitosan. The TMC coated palladium nanoparticles (TMC/PdNPs) exhibited good biocompatibility and physiological stability, as compared to the plain(uncoated) PdNPs. TMC coated PdNPs resulted in photothermal therapeutic effect, when irradiated with a near-infrared (NIR) laser having the wavelength of 808-nm. The TMC/PdNPs resulted in good cytotoxic effect upon laser treatment in both, 2D monolayers and 3D spheroids of MDAMB231 cells, the latter mimicking the tumor microenvironment. These results clearly indicated that TMC/PdNPs acted as ideal photothermal agents for anti-cancer therapy in combination with a non-invasive near-infrared laser.

Degenerative disease-on-a-chip: Developing microfluidic models for rapid availability of newer therapies.

BACKGROUND: Understanding the pathophysiology of degenerative diseases pertaining to nervous system, ocular region, bone/cartilage, and muscle are still being comprehended, thus delaying the availability of targeted therapies. PURPOSE AND SCOPE: Newer micro-physiological systems (organ-on-chip technology) involves development of more sophisticated devices, modelling a range of in vitro human tissues and an array of models for diseased conditions. These models expand opportunities for high throughput screening (HTS) of drugs and are likely to be rapid and cost-effective, thus reducing extensive usage of animal models. CONCLUSION: Through this review article, we aim to present an overview of the degenerative disease models that are presently being developed using microfluidic platforms with the aim of mimicking in vivo tissue physiology and micro-architecture. The manuscript provides an overview of the degenerative disease models and their potential for testing and screening of possible biotherapeutic molecules and drugs. It highlights the perspective of the regulatory bodies with respect to the established-on chip models and thereby enhancing its translational potential.

Greener approach for synthesis of N,N,N-trimethyl chitosan (TMC) using ternary deep eutectic solvents (TDESs).

N,N,N-trimethyl chitosan (TMC), quaternized hydrophilic derivative of chitosan, has been projected to have wide applications in the pharmaceutical industry owing to its improved solubility at physiological conditions. However, the conventional synthesis of TMC involves toxic organic agents, which complicates its use for biological applications. Moreover, these reactions result into unwanted O-methylation and scission of the parent polymer. In the present study we have addressed these limitations by employing a green approach to synthesize TMC, by using lipase as the biocatalyst and dimethyl carbonate (DMC) as the green methylating agent, in a reaction medium comprising of ternary deep eutectic solvents (TDESs). Synthesis of TMC was carried out by using two different lipases from Burkholderia cepacia and Candida rugosa. The resulting TMC was characterized by using FTIR, 1H NMR, DSC, XRD. Methylation was confirmed by FTIR analysis (-CH at 1666 cm-1) and 1H NMR (?? = 3.3 ppm). DSC study revealed a lower thermal stability of TMC as compared to chitosan. These results indicated the possibility of using DMC as a green methylating agent, along with TDESs as green and sustainable solvents, for lipase catalyzed reactions. TMC was successfully synthesized and exhibited a degree of quaternization of about 12.5%, 15.69%, when synthesized used lipases from Burkholderia cepacia and Candida rugosa, respectively.

Cytotoxicity and hemostatic activity of chitosan/carrageenan composite wound healing dressing for traumatic hemorrhage.

Hemorrhage remains a big threat to trauma patients, especially in combat fields. Therefore, we formulated a biocompatible and biopolymer based chitosan/carrageenan composite dressing. This dressing was fabricated using freeze-drying that will serve as a promising material to promote hemostasis and tissue growth required during hemorrhage. The efficacy of dressing was evaluated for its physiochemical analysis, surface morphology, and biodegradability. Further, human dermal fibroblast cells were seeded on dressing and demonstrated non-toxic effects on the cells by showing enhanced cell attachment and proliferation. In vitro hemostatic properties of the dressing were analyzed by human Thrombin-Antithrombin assay. The dressing formed showed steady blood coagulation implying red blood cells and platelet adhesion that helped in thrombin formation, which is responsible for enhancing wound healing. Thus, it is concluded that the composite dressing can be a potent combination to accelerate hemostatic activity against hemorrhage and promote tissue growth for effective wound healing.

Preparation and characterization of biocomposite packaging film from poly(lactic acid) and acylated microcrystalline cellulose using rice bran oil.

Surface acylation of microcrystalline cellulose (MCC) was performed using rice bran oil (RBO). The resultant acylated MCC (RAMCC) exhibited reduced polarity as compared with MCC. Attenuated Total Reflection (ATR)- Fourier transform infrared (FTIR) spectroscopy confirmed hydrophobic MCC modification. RAMCC and MCC were incorporated into PLA matrix and their influence on morphological, mechanical, thermal and barrier properties of the PLA based biocomposite were analyzed. PLA/RAMCC biocomposite (with 2 wt% loading) exhibited lower water sorption compared to PLA film and PLA/MCC. X-ray Diffraction (XRD) analysis result showed an increase in crystallinity of PLA/RAMCC and reduction in water vapour permeability as compared to PLA film and PLA/MCC composite. PLA/RAMCC exhibited the best mechanical, thermal and UV barrier properties. The fractured surfaces of the composites showed an even distribution of RAMCC throughout PLA matrix. Biodegradability of samples was characterized using soil buried method. The cytotoxicity of the developed PLA-based films was evaluated on human dermal fibroblast (HDF) monolayer culture by the MTT method and it has shown that the films were non-cytotoxic thus indicating their biocompatibility and non-toxicity. These biodegradable composite films can be a sustainable utilization of RBO and MCC in the packaging application.

Potential Gene Therapy Towards Treating Neurodegenerative Disea ses Employing Polymeric Nanosystems.

BACKGROUND: Recent integrated approaches involving nanotechnology and gene therapy have accelerated development of efficient drug delivery to the central nervous system (CNS). Neurodegenerative disorders are closely associated with genetic inheritance and mutation. MATERIALS: Nanotechnology has allowed effective engineering of various such polymeric structures. Moreover, availability of a wide array of polymeric materials has enabled fabrication of biocompatible and biodegradable delivery vehicles. Our manuscript focuses on the ideal features and properties of polymeric nanoparticles that have enabled successful gene therapy for neurodegenerative disorders, as well as the challenges that are posing difficulties in their practical application. We have highlighted these aspects through examples of polymeric nanoparticles that have exhibited therapeutic promise in the treatment of neurological disorders and mutations. METHODS: Complete cure of these diseases is a challenging task and gene therapy appears as a realistic approach for their treatment. Gene therapy allows effective replacement or suppression of faulty genes, thereby increasing chances for neuron survival and repair. However, successful delivery of naked genetic material to CNS faces severe obstacles due to possible degradation and restricted transportation of these biological entities across the blood brain barrier (BBB). Structurally, the BBB is composed of several tight junctions, making the membrane highly selective towards the entry of molecules. CONCLUSION: In order to target BBB for treating neurodegenerative diseases, it is essential to develop a tailor-made system that may not only cross this barrier, but also effectively modulate the expression of disease-causing genes. Stabilization of therapeutic genes and their effective, targeted delivery may be possible using polymeric nanoparticles as carriers.