Modares Journal of Biotechnology

Abstract Background: Modern science in drug delivery systems has long been paid to effectively design drug delivery systems, to reduce side effects, increasing bioavailability, targeted drug delivery, and passing through blood-brain barriers. Nanoparticles are very important as carriers because they carry different types of drugs to different parts of the body at the right time. Method: In the present study, thiolated nano chitosan loaded with Biperiden was synthesized by ion gel method using two types of crosslinkers (tripolyphosphate and genipin) and their efficiency was investigated. Results: FTIR analysis confirmed the successful synthesis of various stages of thiolated nano chitosan loaded with Biperiden by both crosslinkers. SEM images showed that as-synthesized nano-carriers have a nanorod structure and nanocarriers crosslinked by genipin had a more regular structure with a size of about 150 nm than nanocarrier crosslinked by TPP with a size of approximately 200 nm. In vitro drug release and cytotoxicity studies showed nano-carriers crosslinked by genipin have had a higher release and less cytotoxicity than nano-carriers crosslinked by TPP. Conclusion: Considering the lower toxicity and delayed release of nanoparticles synthesized with genipine than nanocarriers synthesized with TPP, the use of this nanocarrier increases the bioavailability of the drug and can be used as a suitable drug delivery system.

Abstract Enzymes of marine organisms are ideal candidates for biomonitoring of pollution in marine environments. For the widespread use of enzymes in industrial processes, carried out under certain physico-chemical conditions, their stability must be improved. In this study, for the first time, chitosan nanoparticles were used as matrices for augmenting the stability of Penaeus vannamei (Whiteleg shrimp)-derived purified proteases against metallic ions. For the electrostatic binding of the enzyme to the chitosan nanoparticles, the protein solution at a concentration of 7mg/ml was added to the nanoparticles, and incubated for 4 hours at 10°C. After 3 times rinsing with phosphate buffer of pH=7.5, the nano-enzyme was dissolved in 1ml phosphate buffer, and used for further studies. The results of this study showed that Fe²⁺ and Mn²⁺ significantly increased the enzyme activity, whereas a strong inhibitory effect was observed in the presence of Cd²⁺, Hg²⁺, Co²⁺, Ni²⁺, Cu²⁺ and Zn²⁺, and a weak inhibitory effect in the presence of Na⁺ and K⁺. The immobilized enzyme exhibited greater resistance to metal ions than its free counterpart. The free enzyme was susceptible to the presence of metal ions, and with the increment of their concentrations, enzyme activity declines. From this nexus, it could be inferred that the high stability of immobilized enzyme is due to the presence of chitosan nanoparticles. Stability retention of the immobilized enzyme at high concentrations of metal ions indicates the efficacy and utility of the immobilization method in industrial enzyme technology.

Abstract Biodegradable polymeric nanoparticles are highly regarded in drug delivery due to bioavailability, better encapsulation, controlled release and low toxicity. Drug encapsulation in polymeric nanoparticles may improve the therapeutic effects of these compounds. Polymers are divided in two types: natural and synthetic. Chitosan, as a natural polymer, can have many applications in drug delivery due to good properies. The purpose of this study is to optimization of the production of chitosan nanoparticles for drug delivery. Chitosan nanoparticles were prepared according to ionic gelation method and characterized. Prepared nanoparticle morphology investigated using SEM and particle size distribution, and surface charge and polydispersity index (PDI) were determined by Nanozeta Sizer. FTIR spectra of the lyophilized samples were recorded and proved the formation of nanoparticles. This study has shown that the particle size and zeta potential can be controlled by a change in the ratio of the weight and volume of chitosan and pH adjustment.