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Protein cages have been widely investigated as molecular drug carrier. E2 protein from Bacillus stearothermophillus forms a dodecahedral cage structure of approximately 24 nm in diameter. To formulate a sustainable release profile, E2 protein was further encapsulated into poly(lactide-co-glycolide) (PLGA) microparticles to form a composite structure using water-in-oil-in-water (W/O/W) double emulsion method. The influence of fabrication parameters on microparticle morphology and E2 protein release profile were investigated. The microparticle size increased when the stirring speed of the second emulsification decreased. Decrease in the volume of external aqueous phase led to the reduction of microparticle size without affecting its porosity. The higher ionic concentration of external aqueous phase in the presence of surfactant resulted in microparticles with closed pores on surface. Increase in polymer concentration also led to the formation of less porous microparticles. The E2 protein was not dissociated upon encapsulation into PLGA microparticles based on the unchanged particle size of E2 protein. E2 protein release was studied in phosphate-buffered saline solution at 37°C. The initial burst and release rate were lowered as the surfactant concentration in external water phase during the fabrication process was increased from 0.1% to 1% (w/v). After 14-day incubation, no observable polymer degradation was found while the surface of microparticles appeared to be smoother than before incubation.

Hydrogen is considered as one of the attractive environmentally friendly materials with zero carbon emission. Hydrogen storage is still challenging for its use in various energy applications. That’s why hydrogen gained more and more attention to become a major fuel of today’s energy consumption. Therefore, nowadays, hydrogen storage materials are under extensive research. Herein, efforts are being devoted to design efficient systems which could be used for future hydrogen storage purposes. To this end, we have employed density functional theory (DFT) to optimize the geometries of the designed inorganic Al${}_{12}$N${}_{12}$ nanoclusters with transition metals (Fe, Co, Ni, Cu and Zn). Various positions of metal encapsulated Al${}_{12}$N${}_{12}$ are examined for efficient hydrogen adsorption. After adsorption of H₂ on late transition metals encapsulated Al${}_{12}$N${}_{12}$ nanocluster, different geometric parameters like frontier molecular orbitals, adsorption energies and nature bonding orbitals have been performed for exploring the potential of metal encapsulated for hydrogen adsorption. Moreover, molecular electrostatic potential (MEP) analysis was also performed in order to explore the different charge separation upon H₂ adsorption on metals encapsulated Al${}_{12}$N${}_{12}$ nanoclusters. Also, global indices of reactivity like ionization potential, electron affinity, electrophilic index, chemical softness and chemical hardness were also examined by using DFT. The adsorption energy results suggested encapsulation of late transition metals in Al${}_{12}$N${}_{12}$ nanocage efficiently enhancing the adsorption capability of Al${}_{12}$N${}_{12}$ for hydrogen adsorption. Results of all analysis suggested that our designed systems are efficient candidates for hydrogen adsorption. Thus, we recommended a novel kind of systems for hydrogen storage materials.

Natural gas consists mainly of methane (CH₄) and ethane (CH₃CH₃) and other hydrocarbons in small quantities. Depending on the source it may also contain CO₂, nitrogen (N₂), hydrogen sulfide (H₂S) and helium (He). It is very abundant and its combustion contributes to the increase of the CO₂ content in the biosphere. Natural gas is a non-renewable fuel (Section 5.1). It is widely used to produce electricity, heat, chemicals including hydrogen, and hydrocarbons (liquid fuels) and as a fuel for motor vehicles…