Encapsulation of Nitrilase in Zeolitic Imidazolate Framework-90 to Improve Its Stability and Reusability

Construction of intelligent response gene vector based on MOF/Fe3O4/AuNRs for tumor-targeted gene delivery

Metal-organic frameworks (MOFs) have the potential to efficiently carry cargo due to their excellent porosity and high surface area. Nevertheless, conventional MOFs and their derivatives exhibit low efficiency in transporting nucleic acids and other small molecules, as well as having poor colloidal stability. In this study, a ZIF-90 loaded with iron oxide nanoparticles and Au nanorods was prepared, and then surface-functionalized with polyethyleneimine (PEI) to create a multifunctional nanocomposite (AFZP25k) with pH, photothermal, and magnetic responsiveness. AFZP25k can condense plasmid DNA to form AFZP25k/DNA complexes, with a maximum binding efficiency of 92.85 %. DNA release assay showed significant light and pH responsiveness, with over 80 % cumulative release after 6 h of incubation. When an external magnetic field is applied, the cellular uptake efficiency in HeLa cells reached 81.51 %, with low cytotoxicity and specific distribution. In vitro transfection experiments demonstrated a gene transfection efficiency of 44.77 % in HeLa cells. Following near-infrared irradiation, the uptake efficiency and transfection efficiency of AFZP25k in HeLa cells increased by 21.3 % and 13.59 % respectively. The findings indicate the potential of AFZP25k as an efficient and targeted gene delivery vector in cancer gene therapy.

Molecular Modification Strategies of Nitrilase for Its Potential Application in Agriculture

Some feed source plants will produce secondary metabolites such as cyanogenic glycosides during metabolism, which will produce some poisonous nitrile compounds after hydrolysis and remain in plant tissues. The consumption of feed-source plants without proper treatment affect the health of the animals' bodies. Nitrilases can convert nitriles and have been used in industry as green biocatalysts. However, due to their bottleneck problems, their application in agriculture is still facing challenges. Acid-resistant nitrilase preparations, high-temperature resistance, antiprotease activity, strong activity, and strict reaction specificity urgently need to be developed. In this paper, the application potential of nitrilase in agriculture, especially in feed processing industry was explored, the source properties and catalytic mechanism of nitrilase were reviewed, and modification strategies for nitrilase application in agriculture were proposed to provide references for future research and application of nitrilase in agricultural and especially in the biological feed scene.

Synthesis and Biomedical Applications of Highly Porous Metal-Organic Frameworks

In this review, aspects of the synthesis, framework topologies, and biomedical applications of highly porous metal-organic frameworks are discussed. The term "highly porous metal-organic frameworks" (HPMOFs) is used to denote MOFs with a surface area larger than 4000 m² g^-1. Such compounds are suitable for the encapsulation of a variety of large guest molecules, ranging from organic dyes to drugs and proteins, and hence they can address major contemporary challenges in the environmental and biomedical field. Numerous synthetic approaches towards HPMOFs have been developed and discussed herein. Attempts are made to categorise the most successful synthetic strategies; however, these are often not independent from each other, and a combination of different parameters is required to be thoroughly considered for the synthesis of stable HPMOFs. The majority of the HPMOFs in this review are of special interest not only because of their high porosity and fascinating structures, but also due to their capability to encapsulate and deliver drugs, proteins, enzymes, genes, or cells; hence, they are excellent candidates in biomedical applications that involve drug delivery, enzyme immobilisation, gene targeting, etc. The encapsulation strategies are described, and the MOFs are categorised according to the type of biomolecule they are able to encapsulate. The research field of HPMOFs has witnessed tremendous development recently. Their intriguing features and potential applications attract researchers' interest and promise an auspicious future for this class of highly porous materials.

Preparation, characterization and stability of cross linked nitrilase aggregates (nitrilase-CLEAs) for hydroxylation of 2-chloroisonicotinonitrile to 2-chloroisonicotinic acid

Nitrilases capable of performing hydroxylation of 2-chloroisonicotinonitrile to 2-chloroisonicotinic acid were screened, and ES-NIT-102 was the best nitrilase for said biotransformation. Nitrilase was immobilized as cross linked enzyme aggregates (nitrilase-CLEAs) by fractional precipitation with iso-propanol, and cross linked with glutaraldehyde. The nitrilase-CLEAs prepared with optimized 35 mM glutaraldehyde for 120 min cross linking time had 82.36 ± 4.45% residual activity, and displayed type-II structural CLEAs formation as confirmed by particle size, SEM, FTIR, and SDS-PAGE analysis. Nitrilase-CLEAs had superior pH and temperature stability, showed a shift in optimal temperature by 5 °C, and retained nearly 1.5 to 1.7 folds activity over free nitrilase at 50 °C and 55 °C after more than 9 h incubation. Nitrilase-CLEAs showed reduced affinity and decreased conversion of substrate as indicated by slightly higher K_m values by 5.19% and reduced V_max by 17%. Furthermore, these nitrilase-CLEAs showed 98% conversion, 94.72 g/L product formation, and 83.30% recovery after 24 h when used for hydroxylation of 2-chloroisonicotinonitrile to 2-chloroisonicotinic acid. Nitrilase-CLEAs were catalytically active for 3 cycles showcasing 81% conversion, 75.53 g/L product formation and 66.42% yield. The recovered product was confirmed by HPLC, FTIR, LC-MS, and ¹H NMR, and displayed > 99% purity.