Background: Due to the lack of efficient anti-HIV vaccine, anti-HIV pharmaceuticals play an important role in controlling HIV infection. Also significant rise in drug resistance and drug toxicity has caused increased interest in finding new anti-HIV agents. In this study, a nano-sized version of lamivudine based on PEGylated chitosan was synthesized.

  Materials and Methods: In this research, nanoparticles of chitosan were efficiently PEGylated for increasing their stability in water and then the anti-HIV drug, lamivudine, was loaded on these PEGylated nanoparticles. After purification and lyophilization of new synthesized nanoparticle, the raw materials and final product were sampled and FTIR, HNMR and CHN analyses were done.

  Results: Results of HNMR spectroscopy showed that chitosan nanoparticle was successfully PEGylated. HNMR data confirmed FTIR results and indicated that lamivudine was conjugated on chitosan nanoparticle. In addition, CHN analysis data also confirmed both HNMR and FTIR data, and demonstrated that a high yield of chitosan nanoparticle PEGylation (approximately 97%) was done and illustrated a high capacity of lamivudine conjugation on nano-sized PEGylated chitosan (30% _W/W chitosan).

  Conclusion: In this study, lamivudine drug was successfully synthesized, based on PEGylated chitosan nanoparticle.

Background: Gene therapy is a recent promising treatment that effective gene transfer is considered as its most important step. Furthermore noninvasive method of transfer will be important to, when gene therapy is supposed to be applied. Administration of drugs in oral rout is more appreciated by patients. Loading and release rates are very important in targeting and effectiveness of transfer in all different methods that have been used for oral drug transfer. Here, we have studied packing of gene particles into two different enteric coats and compared these two coats in loading of entrapped materials and there release rate in vitro.

Materials and Methods: First, DNA was mixed with chitosan by coacervation technique and resulted polyplexes were coated using solvent evaporation technique. FTIR and two different pHs, less and more but near eudragit pKa, were used to evaluate formation of particles and their behavior.

Results: Formed particles have similar stability in low pH and their differences are trivial. Eudragit L100 release rate is really slower than L100-55 and gradual. Eudragit L100 shows better ability in loading rate.

Conclusion: According to two formed particles' behavior, eudragit L100-55 might be used in oral gene transfer targeting of initial part of small intestine and eudragit L100 might be used for wider surface of small intestine, from the initial to the end part, and colon.

Background: chitin and its derivates microparticles (MPs) have immunomodulatory activities. In this study, we examined the effect of size, purity and acetylation degree of chitin MPs on CHID1- encoding SI-CLP, involved in inflammation- gene expression in mixed leukocyte culture.

Materials and Methods: Small (<40m) and medium(40-70m) sized chitin MPs were prepared by sonication, and they were used in treatment of leukocyte mixed culture in comparison with chitosan and also shrimp shell small-sized MPs. Neutral red uptake assay and microscopic examination of apoptosis were used to assess cytotoxicity of MPs. Finally, following cell treatment with MPs (100 μg/mL) for 48h, expression levels of CHID1 gene were determined by Real Time PCR.

Results: Different concentrations of chitinous MPs hadn’t any cytotoxic effects. In gene expression analysis, small-sized chitin MPs (<40 µ) resulted in down regulation of CHID1 gene expression (p=0.004), while other MPs didn’t change it significantly.

Conclusion: Size, purity and acetylation degree of chitin MPs influence their interference in immune cells interactions and it seems small-sized chitin MPs can potentially modulate immune responses through decreasing CHID1 gene expression. Using small-sized chitin MPs may be effective to treat allergies which their treatment strategies rely on modulating the immune responses.