Zeolites in drug delivery: Progress, challenges and opportunities.

There are continuing attempts to achieve appropriate controlled-release therapeutic systems by designing innovative functional drug delivery systems (DDS). Although various types of delivery system have been developed, strategies that have successfully made it to the clinic are rare. Given their diverse structures, zeolites have attracted significant research attention for controlled and targeted drug delivery purposes. The structure of zeolites can be microporous, mesoporous or macroporous, which can be exploited to deliver a variety of therapeutic agents to the target site in a controlled manner. In this review, we introduce the different types of zeolite, and discuss the challenges and opportunities associated with their usage as drug delivery systems.

Zeolite in tissue engineering: Opportunities and challenges.

Tissue engineering and regenerative medicine follow a multidisciplinary attitude to the expansion and application of new materials for the treatment of different tissue defects. Typically, proper tissue regeneration is accomplished through concurrent biocompatibility and positive cellular activity. This can be resulted by the smart selection of platforms among bewildering arrays of structural possibilities with various porosity properties (ie, pore size, pore connectivity, etc). Among diverse porous structures, zeolite is known as a microporous tectosilicate that can potentially provide a biological microenvironment in tissue engineering applications. In addition, zeolite has been particularly appeared promising in wound dressing and bone- and tooth-oriented scaffolds. The wide range of composition and hierarchical pore structure renders the zeolitic materials a unique character, particularly, for tissue engineering purposes. Despite such unique features, research on zeolitic platforms for tissue engineering has not been classically presented. In this review, we overview, classify, and categorize zeolitic platforms employed in biological and tissue engineering applications.

Potential of tri-reforming process and membrane technology for improving ammonia production and CO2 reduction.

In this work, a tri-reforming process was coupled with a membrane separation unit to enhance efficiency of ammonia (NH3) synthesis process in terms of CO2 emission, NH3 production, and NOx emission. Primary and secondary reformers were replaced by a tri-reforming process, while a Perovskite membrane was applied to separate nitrogen (N2) from oxygen (O2). A conventional NH3 synthesis process and the proposed process were simulated by Aspen-Hysys and compared in order to investigate the performance of the proposed sterategy. The simulation results indicated that when temperature increased and pressure decreased, conversion of hydrocarbons and H2/CO ratio were improved from 1.73 to 2.54, which resulted in an increase in NH3 production by 27 %, and a decrease in CO2 emission rate from 1192 kg/h to approximately 1 kg/h. The proposed sterategy was optimized in terms of different parameters e.g., temperature and pressure. Optimum reaction pressure and temperature were determined to be between 1 and 10 bar and 500-800 °C, respectively. The results of the study revealed that the proposed strategy not only removed amine and methanol sweeteners which reduce the operational costs of the process, but also decreased the NOx content from 8220 ppm to almost 10 ppm.