Nano LIFE

The applications of stem cells in tissue engineering will show great promise in generating tailor-made tissue/organs for clinical applications. This paper gives a review on a broad spectrum of areas in stem cell-based tissue engineering including neuron repair, cardiac patches, skin regeneration, gene therapy and cartilage tissue engineering. This paper is intended to serve as an informative tutorial for scientists and physicians from fields other than stem cells and tissue engineering. It will shed light on various strategies of target tissue/organ repair involving stem cells.

A comparative study of magnetic properties using the method of magnetometry with vibration magnetometer and spectra of electron paramagnetic resonance (EPR) nanocomplexes (NCs) of nanoparticles Fe₂O₃, Fe₃O₄ and antitumor antibiotic doxorubicin (DOXO) have shown that changes in saturation magnetic moments are similar to changes in integral intensity of EPR spectra. The greatest magnetic moments of saturation and integral intensity of EPR spectra were demonstrated by samples of Fe₃O₄ in NC with doxorubicin, which had the highest antitumor effect in radiofrequency hyperthermia of Walker-256 carcinosarcoma. The presented research provides the evidence of stronger antitumor effect of Fe₃O₄ and DOXO NC in comparison to NC from γ-Fe₂O₃ and DOXO at combined action of constant magnetic field and electromagnetic field. This can be a basis for development of bioengineering technology of magnetic cancer nanotherapy in conditions of moderate hyperthermia (< 39°C).

The 23 amino acid-long extracellular domain of the influenza virus transmembrane protein M2 (M2e) has remained highly conserved since the 1918 pandemic, and is thus considered a good candidate for development of a universal influenza A vaccine. However, M2e is poorly immunogenic. In this study we assessed the potential of increasing immunogenicity of M2e by constructing a nanoscale-designed protein polymer containing the M2e sequence and an elastin-like polypeptide (ELP) nanodomain consisting of alanine and tyrosine guest residues (ELP(A₂YA₂)₂₄). The ELP nanodomain was included to increase antigen size, and to exploit the inherent thermal inverse phase transition behavior of ELPs to purify the protein polymer. The ELP(A₂YA₂)₂₄ + M2e nanodomained molecule was recombinantly synthesized. Characterization of its inverse phase transition behavior demonstrated that attachment of M2e to ELP(A₂YA₂)₂₄ increased its transition temperature compared to ELP(A₂YA₂)₂₄. Using a dot blot test we determined that M2e conjugated to ELP is recognizable by M2e-specific antibodies, suggesting that the conjugation process does not adversely affect the immunogenic property of M2e. Further, upon vaccinating mice with ELP(A₂YA₂)₂₄ + M2e it was found that indeed the nanodomained protein enhanced M2e-specific antibodies in mouse serum compared to free M2e peptide and ELP(A₂YA₂)₂₄. The immune serum could also recognize M2 expressed on influenza virions. Overall, this data suggests the potential of using molecules containing M2e-ELP nanodomains to develop a universal influenza vaccine.

Metal-oxide nanoparticles with high surface area, controllable functionality and thermal and mechanical stability provide high affinity for enzymes when the next generation of biosensor applications are being considered. We report on the synthesis of metal-oxide-based nanoparticles (with different physical and chemical properties) using hydrothermal processing, photo-deposition and silane functionalization. Physical and chemical properties of the user-synthesized nanoparticles were investigated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and Raman scattering, respectively. Thus, characterized metal-oxide-based nanoparticles served as nanosupports for the immobilization of soybean peroxidase enzyme (a model enzyme) through physical binding. The enzyme–nanosupport interface was evaluated to assess the optimum nanosupport characteristics that preserve enzyme functionality and its catalytic behavior. Our results showed that both the nanosupport geometry and its charge influence the functionality and catalytic behavior of the bio-metal-oxide hybrid system.