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.

Packaging materials based on biodegradable polymers are a viable alternative to replacing conventional plastic packaging of fossil origin. The main two factors affecting functionality and performance are the molecular weight and the type of plasticizer used in these materials. The goal of this research was to modify unfractionated plasticized chitosan films to improve the physical and mechanical characteristics of the original unfractionated chitosan films. Chitosan extracted from local shrimp shells was zone-refined to produce five distinct chitosan fractions with molecular weights ranging from 1.089×105 to 5.605×105 g/mole. The unfractionated and fractionated chitosan films plasticized with 1:3 poly(vinyl alcohol) and 2:1 maleic acid were prepared by casting from their 2% acetic acid solutions. They were examined by FT-IR and were found to be comparable to the native chitosan spectrum, indicating that the primary backbone of the chitosan structure was unaltered. Therefore, the effects of molecular weight fractions and the type of plasticizer on the physical and mechanical properties were investigated. Examining the films’ surface topography by atomic force microscopy revealed that increasing the molecular weight of chitosan fractions from 2.702×105 to 5.605×105 g/mole affects the surface morphology of the chitosan: poly(vinyl alcohol) (1:3) film. This was accompanied by an increase in the surface roughness of the resulting film from 0.953 to 2.82, and for chitosan: maleic acid from 0.509 to 1.62. It was found that the tensile strength and Young’s modulus of the cast films decreased and the percent elongation at break of the plasticized fractionated chitosan films was increased, implying that less stiff films were obtained with fractionated chitosan. The outcome of this work suggests that the biodegradable fractionated chitosan blend film is a promising packaging material and that poly(vinyl alcohol) is the most suitable plasticizer for this formulation.

The energy crisis and environmental concerns have increased interest in natural polymers, and the bio-sourced materials field is experiencing rapid growth. A useful alternative to conventional plastic packaging manufactured from fossil fuels is packaging constructed of biodegradable polymers. Consideration has been given to the instrumental methods for examining modifications to the chemical composition and characteristics of modified chitosan. The molecular weight and the kind of plasticizer present in these materials are the two primary variables influencing their usability and performance. This study set out to physically blend chitosan with two different acids, lauric and maleic, to enhance chitosan cast films' physical and mechanical properties. Different plasticizer ratios appeared to have little effect on the various properties of the chitosan cast films. Examining the obtained films by FTIR implies that chitosan's native structure was unchanged. The films prepared had more flexibility and better solubility than those made with un-plasticized chitosan. It was evident from an analysis of the mechanical properties of the films that both acid plasticizers enhanced the mechanical properties of the chitosan.

Biodegradable polymer-based packaging materials are a practical replacement for traditional plastic packaging made of fossil fuels. The molecular weight and the kind of plasticizer present in these materials are the two primary variables influencing their usability and performance. This study set out to physically blend chitosan to enhance the physical and mechanical properties of chitosan cast films. A chitosan extract with a molecular weight of 2.702x105 g/mole with an 80% degree of deacetylation level was produced from the shells of local shrimp. Chitosan films plasticized with varied w/w ratios of diethylene glycol and poly(ethylene glycol) with molecular weights of 400 and 1500 g/mole were produced by casting from 2%acetic acid solutions. By using FTIR to analyze them, it was found that their spectra were compared to those of native chitosan, showing that the main backbone of the chitosan structure was unaffected. An examination of the mechanical properties of the films revealed that the results of the tensile strength measurement showed that the combination of diethylene glycol and poly(ethylene glycol) improved the mechanical properties of chitosan as films were obtained with more elasticity than unplasticized chitosan with better solubility.