Introduction: Chitosan is one of the natural polymers can generally consider as a biocompatible and biodegradable polycationic polymer, which has minimum immunogenicity and low cytotoxicity. Therefore, chitosan and its derivatives may represent potentially safe cationic carriers for use in gene delivery.Materials and Methods: Chitosan with 90.1 DD% obtained by deacetylation of chitin extracted from local shrimp shells. Graft copolymerization of L-lactide onto chitosan was carried out at room temperature by ring opening polymerization under a nitrogen atmosphere to prepare chitosan-g-poly (N-lactide) graft copolymer. It was obtained in good yield and characterized by FTIR. The samples purity and concentration were detected using both Nanodrop UV-spectroscopy and agarose gel electrophoresis techniques. The human heat shock proteins gene, hsp-70, was used as a model of human genes to study the effect of chitosan-g-poly(N-lactide) graft copolymer. Results and Discussion: The results revealed that chitosan-g-poly (N-lactide) graft copolymers had safety effect on the DNA, and binding with it. the human heat shock proteins gene, hsp-70, was used as a model of human genes to study the effect of chitosan-g-poly(N-lactide) graft copolymer, it shows a good binding ability the human gene, implies that it might be used in biomedical applications in the future. Conclusions: Grafting of L-lactide onto chitosn by ring opening polymerization was confirmed by FTIR.   The repaired polymer has safety effects on human DNA and genes. The chitosan-g-poly (N-lactide) graft copolymer has shown high efficiency to electrostatic interaction with human DNA and gene, implying that it is suitable to be used as DNA and gene delivery.

Abstract. The presence of reactive primary amines in the backbone structure of chitosan enables the derivatization with different functional groups and thereby improving and expanding its properties, such as solubility and mucoadhesiveness, for biomedical applications. In this work, chitosan was grafted with different sources of amino acids (Histidine, Aspartic acid, Glutamic acid, Glycine-Aspartic acid, and Glycine-Glutamic acid), Chitosan and its grafted amino acid derivatives were obtained in very good yield, and they were characterized by Fourier-Transform Infrared Spectroscopy (FTIR), and the resulted spectra confirmed the right structures of chitosan and its different synthesized derivatives. The chitosan and its amino acid derivatives were converted to nanoparticles in size by subjecting them to the sonication method. The Scanning Electron Microscope (SEM) was used to determine the shape and size of the prepared polymeric nanoparticles and the average nanoparticle size counted by the Image-J program. The micrographs revealed that the nanoparticles with spherical shapes and with different sizes were gained, but in general, they are less than 100nm in diameters. In vitro cytotoxicity of chitosan and chitosan derivatives prepared NPs were determined as MTT assay, against different three types of human breast cancer cell lines which are BT cell lines, MCF-7 cell lines, and SKBR3 cell lines. The cell proliferation of each type of breast cancer cell line has appeared to a highly significant decrease (p<0.001), with all types of tested NPs polymers in comparison with the positive control samples, through different periods of the experiment (24, 48, and 72 hours).   Resumen. La presencia de aminas primarias reactivas en la estructura del quitosano permite su funcionalización con diferentes grupos funcionales, mejorando y expandiendo sus propiedades, por ejemplo, solubilidad y mucoadhesividad, para aplicaciones biomédicas. En este trabajo se injertó quitosano con diferentes fuentes de aminoácidos (histidina, ácido aspártico, ácido glutámico, glicina-ácido aspártico y glicina-ácido glutámico). Los derivados de quitosano injertados con aminoácidos se obtuvieron con muy buen rendimiento. La caracterización por espectroscopía infrarroja (FTIR) confirmó la funcionalización del quitosano. Después de sonicación y una caracterización por microscopía electrónoica de barrido (SEM), se confirmó que el tamaño del quitosano y sus derivados con aminoácidos pueden clasificarse como nanopartículas. Las micrografías revelaron que las nanopartículas tienen formas esféricas y son de diferentes tamaños, pero en general, son menores a 100 nm de diámetro. La citotoxicidad in vitro de las nanopartículas de quitosano y derivados de quitosano se determinó como ensayos MTT frente a tres tipos diferentes de líneas celulares de cáncer de mama humano, a saber, líneas celulares BT, líneas celulares MCF-7 y líneas celulares SKBR3. La proliferación celular de cada tipo de línea celular de cáncer de mama mostró una disminución significativa (p <0.001), con todos los tipos de polímeros NP probados en comparación con las muestras de control positivo, a lo largo de diferentes períodos del experimento (24, 48, y 72 horas).

C HITOSAN, a natural macromolecule, is widely used in medical and pharmaceutical fields because of its distinctive properties such as a bactericide, fungicide and above all its antitumour effects. In this study; we aimed to develop an antitumour system based on Chitosan (Cs)and its some amino acid derivatives, namely Chitosan-Arginine (Cs-Arg) and Chitosan-Clycine-Aspartic acid (Cs-Gly-Asp)derivatives nanoparticles to improve their bioavailability and anticancer activity in antitumour treatments. The derivatives were obtained in a very good yield, and they were characterized by FTIR and some of them characterized by 1H-NMR, and the resulted spectra confirmed the right structures of synthesized chitosan derivatives. All the chitosan and its grafted amino acids were converted to nanoparticles in size by subjecting them to the sonication method. The scanning electron microscope (SEM) was used to determine the shape and size of the prepared polymeric nanoparticles, and they developed using the ImageJ program. The MTT assay and the flow cytometry technique for all prepared polymeric nanoparticles were determined against three different types of human breast cancer cell lines, and the results revealed the highly significant (p< 0.001), in the reducing of breast carcinoma viability in comparison with untreated cell lines, but the cytotoxicity effect of Cs-Arg nanoparticles were larger than Cs-Gly-Asp nanoparticles, whereas there was no genotoxicity effect against BT cell lines for the Cs-Gly-Asp nanoparticles and slight effect for Cs-Arg nanoparticles.

Illicit drug use represents a worldwide health problem involving about 5% of world's adult population and contributing to crime misery and insecurity. A widely used illicit drug in Iraq in recent years is Captagon, which is second only to methamphetamine. It is also popular in Middle East especially in Syria, Saudi Arabia and Kuwait. It is the brand name of chemical compound Fenethylline, and it is a derivative substantial of amphetamines. It is amphetamine coupled with theophylline via an alkyl chain. We used a rapid, low-cost colorimetric assay for sensitive and visual detection of Captagon in real human samples using a Captagon-specific aptamer as the recognition element and original gold nanoparticles as indicators. The method indicated that the presence of Captagon resulted in gold nanoparticles (Au NPs) solution's color change from purple to blue. The method was rapid and also worked well in human urine samples, blood and hair. Colorimtric detection of Captagon could be measured either visually or by measurement of the absorbance intensity ratios at 650 and 520 nm, respectively. It worked in the 2 μM to 50 μM concentration range. Selectivity of captgon detection method was also investigated with illicit and licit drugs, which revealed that an obvious change both in absorption spectra and in visual color was observed upon the addition of Captagon, whereas slight and negligible change occurred in the presence of any examined drugs with the similar concentration as Captagon. Our findings presented that hair was a good example for detection of drug history of Captagon and other illicit drugs compared with urine and blood, which is believed to represent a widely applicable aptamer-based detection system.

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