Infection with Mycobacterium tuberculosis remains a major cause of morbidity and mortality all over the world. Since the effectiveness of the only available tuberculosis vaccine, Mycobacterium bovis bacillus CalmetteGuérin (BCG), is suboptimal, there is a strong demand to develop new tuberculosis vaccines. As tuberculosis is an airborne disease, the intranasal route of vaccination might be preferable. Live influenza virus vaccines might be considered as potential vectors for mucosal immunization against various viral or bacterial pathogens, including M. tuberculosis. We generated several subtypes of attenuated recombinant influenza A viruses expressing the 6-kDa early secretory antigenic target protein (ESAT-6) of M. tuberculosis from the NS1 reading frame. We were able to demonstrate the potency of influenza virus NS vectors to induce an M. tuberculosisspecific Th1 immune response in mice. Moreover, intranasal immunization of mice and guinea pigs with such vectors induced protection against mycobacterial challenge, similar to that induced by BCG vaccination.Since reverse genetics methods have been developed for negative-strand RNA viruses (30, 33), influenza viruses can be considered as viral vectors for immunization against different pathogens. The influenza A virus contains a segmented genome consisting of eight negative-strand RNA fragments. Among them, the smallest fragment (NS), encoding two proteins (NS1 and Nep), is a suitable target for genetic manipulation. NS1 is the only nonstructural protein of the influenza virus and has been shown to tolerate relatively long insertions of more than 250 amino acids (23). Moreover, as the NS1 protein is produced in large quantities in infected cells, expression of foreign sequences from the NS1 reading frame should result in a strong immune response against the inserted antigen. It was demonstrated that immunization of mice with NS influenza virus vectors could trigger a CD8 ϩ T-cell response, especially when two vectors belonging to different influenza virus subtypes were used for prime-boost immunizations (12, 39). However, influenza virus NS vectors might be less efficient for the induction of insert-specific T-helper and antibody responses due to the intracellular localization of the NS1 protein leading to a less efficient presentation of linked antigen through the major histocompatibility complex class II pathway.In this work, we tested the potential of recombinant influenza virus NS vectors expressing a Mycobacterium tuberculosis antigen to induce T-helper response after intranasal immunization of mice. It is accepted that control over tuberculosis infection depends on the recruitment of antigen-specific T cells, mainly CD4 ϩ cells, to the lungs and the release of cytokines, particularly gamma interferon (IFN-␥), to trigger the bacterium-killing mechanisms in activated macrophages (14). We constructed a recombinant influenza virus NS gene for the expression of the 6-kDa early secretory antigenic target protein (ESAT-6) derived from M. tuberculosis and introduc...

The development of biocompatible composite materials is in high demand in many fields such as biomedicine, bioengineering, and biotechnology. In this study, two series of poly (D,L-lactide) and poly (ε-caprolactone)-based films filled with neat and modified with poly (glutamic acid) (PGlu) nanocrystalline cellulose (NCC) were prepared. An analysis of scanning electron and atomic force microscopies’ results shows that the modification of NCC with poly (glutamic acid) favored the better distribution of the nanofiller in the polymer matrix. Investigating the ability of the developed materials to attract and retain calcium ions led to the conclusion that composites containing NCC modified with PGlu induced better mineralization from model solutions than composites containing neat NCC. Moreover, compared to unmodified NCC, functionalization with PGlu improved the mechanical properties of composite films. The subcutaneous implantation of these composite materials into the backs of rats and the further histological investigation of neighboring tissues revealed the better biocompatibility of polyester materials filled with NCC–PGlu.

In the present study, a poly- l -lactide/silk fibroin (PL-SF) bilayer scaffold seeded with allogenic bone marrow stromal cells (BMSCs) was investigated as a potential approach for bladder tissue engineering in a model of partial bladder wall cystectomy in rabbits. The inner porous layer of the scaffold produced from silk fibroin was designed to promote cell proliferation and the outer layer produced from poly- l -lactic acid to serve as a waterproof barrier. To compare the feasibility and efficacy of BMSC application in the reconstruction of bladder defects, 12 adult male rabbits were divided into experimental and control groups (six animals each) that received a scaffold seeded with BMSCs or an acellular one, respectively. For BMSC tracking in the graft in in vivo studies using magnetic resonance imaging, cells were labeled with superparamagnetic iron oxide nanoparticles. In vitro studies demonstrated high intracellular incorporation of nanoparticles and the absence of a toxic influence on BMSC viability and proliferation. Following implantation of the graft with BMSCs into the bladder, we observed integration of the scaffold with surrounding bladder tissues (as detected by magnetic resonance imaging). During the follow-up period of 12 weeks, labeled BMSCs resided in the implanted scaffold. The functional activity of the reconstructed bladder was confirmed by electromyography. Subsequent histological assay demonstrated enhanced biointegrative properties of the PL-SF scaffold with cells in comparison to the control graft, as related to complete regeneration of the smooth muscle and urothelium tissues in the implant. Confocal microscopy studies confirmed the presence of the superparamagnetic iron oxide nanoparticle-labeled BMSCs in newly formed bladder layers, thus indicating the role of stem cells in bladder regeneration. The results of this study demonstrate that application of a PL-SF scaffold seeded with allogenic BMSCs can enhance biointegration of the graft in vivo and support bladder tissue regeneration and function.