Cloning, purification and characterization of human dentine matrix protein 1(DMP1).

Introduction: Human teeth are composed mainly of dentin, formed by the odontoblasts. Dentin matrix protein 1 (DMP1) is one of odontoblast differentiation's most important growth factors. Human DMP1 has yet to be completely identified or studied. This study aimed to clone and characterize human DMP1. Materials and methods: The DMP1 gene sequence was prepared and cloned by transfection of human 293 cells. Results: The recombinant DMP1 was purified and characterized. Conclusion: The results suggested its future use in dental tissue regeneration and tissue engineering.

Poly(glycerol sebacate) nanoparticles for ocular delivery of sunitinib: physicochemical, cytotoxic and allergic studies.

Poly(glycerol sebacate) (PGS) is a new biodegradable polymer with good biocompatibility used in many fields of biomedicine and drug delivery. Sunitinib-loaded PGS/gelatine nanoparticles were prepared by the de-solvation method for retinal delivery and treatment of diabetic retinopathy. The nanoparticles were characterised by Fourier-transform infrared and differential scanning calorimetry. The effects of different formulation variables including drug-to-carrier ratio, gelatine-to-PGS ratio, and glycerine-to-sebacate ratio were assessed on the encapsulation efficiency (EE%), particle size, release efficiency (RE), and zeta potential of the nanoparticles. The in vitro cytotoxicity of PGS/gelatine nanoparticles was studied on L929 cells. Draize test on rabbit eyes was also done to investigate the possible allergic reactions caused by the polymer. Glycerine/sebacic acid was the most effective parameter on the EE and RE. Gelatine-to-PGS ratio had the most considerable effect on the particle size while the RE was more affected by the glycerine/sebacic acid ratio. The optimised formulation (S1G0.7D21.2) exhibited a particle size of 282 nm, 34.6% EE, zeta potential of -8.9 mV, and RE% of about 27.3% for drug over 228 h. The 3-(4,5-dimethylthuazol-2-yl)-2,5-diphenyltetrazolium bromide assay indicated PGS/gelatine nanoparticles were not cytotoxic and sunitinib-loaded nanoparticles were not toxic at concentrations <36 nM.

Two Dimensional Structural Analysis and Expression of a New Staphylococcus aureus Adhesin Based Fusion Protein.

OBJECTIVES: Staphylococcus aureus is a foremost source of numerous nosocomial and community acquired infections. Antibiotic therapy for vancomycin resistant S. aureus (VRSA) can not promise the eradication of infections. Since adhesion is the major route of infections, adhesin based vaccine could suppress S. aureus infections. Fibronectin binding protein A (FnBPA) and clumping factor A (ClfA) are major responsible adhesions involved in S. aureus infections, so they could be candidate vaccine molecules against an extensive range of infections. This project intended to express a new fusion protein construct and analysis of biological activity regarding binding activity. MATERIALS AND METHODS: pfnbA- ClfA construct was transformed to Escherichia coli BL21 (DE3). Transformant E. coli were grown in LB broth and induced with IPTG and cellular extracts were separated on SDS-PAGE. RT-PCR was performed to verify expression. Binding activity of fusion protein was studied using human gingival fibroblast (HGF) cell line. D1-D3 protein from unpublished study was used as control. RESULTS: The expected fusion protein fragment showed by SDS-PAGE. RT-PCR verified the existence of mRNA relating to expressed fusion protein. Binding activity of S. aureus decreased after treatment of HGF cells with fusion protein. CONCLUSION: In total, binding activity of fusion protein was approximately two fold lesser than D1-D3 protein. It is supposed that the fusion protein could not be attached to its ligand easily and would be more accessible to antigen presenting cells and consequently protective antibodies will be produced. This project is pending for in vivo infection study in animal model.