Polymer-Coated NH2-UiO-66 for the Codelivery of DOX/pCRISPR

Prevascularized Micro-/Nano-Sized Spheroid/Bead Aggregates for Vascular Tissue Engineering

Efficient strategies to promote microvascularization in vascular tissue engineering, a central priority in regenerative medicine, are still scarce; nano- and micro-sized aggregates and spheres or beads harboring primitive microvascular beds are promising methods in vascular tissue engineering. Capillaries are the smallest type and in numerous blood vessels, which are distributed densely in cardiovascular system. To mimic this microvascular network, specific cell components and proangiogenic factors are required. Herein, advanced biofabrication methods in microvascular engineering, including extrusion-based and droplet-based bioprinting, Kenzan, and biogripper approaches, are deliberated with emphasis on the newest works in prevascular nano- and micro-sized aggregates and microspheres/microbeads.

Dual functions of pH-sensitive cation Zr-MOF for 5-Fu: large drug-loading capacity and high-sensitivity fluorescence detection

Nanomaterials, as carriers of small molecular drugs, have been a focal point in recent years. In this work, a carbazolyl functionalized metal-organic framework, UiO-67-CDC, was successfully synthesized employing the ligand 9H-carbazole-2,7-dicarboxylic acid (9H-2,7-CDC). Postsynthetic approaches targeted the cationization and replacement of the Lewis base carbazole site with two methyl groups, resulting in the positively charged skeleton, which has proven to be a promising carrier for the anticancer drug 5-fluorouracil (5-Fu). The prepared cationic framework UiO-67-CDC-(CH3)2 showed moderately high surface area, hierarchical pore structures, and positive surface characteristics, which effectively and selectivity encapsulated the electron-rich 5-Fu molecules through electrostatic attraction, with a relatively high loading of up to 56.5% (wt%). The drug delivery in simulated blood environment (pH = 7.4) exhibited a more effective release, demonstrating a physiological pH-responsive sustained release. Significantly, the electron-deficient Zr-MOF itself, as a kind of high-sensitivity fluorescence detector, has a unique fluorescence "turn-on" effect with 5-Fu. These results pave the way towards designing surface-engineered MOF materials of interest in drug delivery and fluorescent sensing applications.

A pseudohomogeneous nanocarrier based on carbon quantum dots decorated with arginine as an efficient gene delivery vehicle

A pseudohomogeneous carrier as an emerging term refers to subnanometric carbon-based vehicle with a high ability to interact with genetic materials to form stable carboplex and successfully transfer them into the cell which will result in inhibiting or expressing of therapeutic genes. Chitosan is a non-toxic polyaminosaccharide used as a precursor in the presence of citric acid to produce carbon quantum dots (CQDs), which decorated with arginine as a surface passivation agent with high amine density in hydrothermal methodology. The Arginine-CQDs are comprehensively characterized by Fourier-transform infrared spectroscopy (FT-IR), Ultraviolet-visible spectroscopy (UV-vis), Atomic force microscopy (AFM), field emission scanning electron microscope (FE-SEM), Energy-dispersive X-ray (EDX) mapping, fluorescence, High-resolution transmission electron microscopy (HR-TEM), zeta potential and X-ray powder diffraction (XRD). In this regard, for the first time, carboplex are formed by electrostatic conjugating of Arginine-CQDs with DNA to protect it from enzymatic degradation. Moreover, the carboplex, like the chitosan precursor, has not shown toxicity against AGS cell line. Interestingly, the Arginine-CQDs have exhibited an excellent ability to overcome cell barriers to deliver into cells compared to chitosan at the same weight ratio. The Arginine-CQDs/pEGFP (W/W) nanocomplex, not only lead to transfection with a relatively higher efficiency than PEI polymer, which is the "golden standard", but carboplex also demonstrates no significant toxicity. Indeed, the EGFP expression level has reached to 2.4 ± 0.2 via Arginine-CQDs carboplex at W/W 50 weight ratio. To the best of our knowledge, this is the first report includes chitosan-based CQDs functionalized by arginine which is applied to serve as a pseudohomogeneous vehicle for gene transfection.

Metal-Organic Frameworks-Based Nanomaterials for Drug Delivery

The composition and topology of metal-organic frameworks (MOFs) are exceptionally tailorable; moreover, they are extremely porous and represent an excellent Brunauer-Emmett-Teller (BET) surface area (≈3000-6000 m2·g-1). Nanoscale MOFs (NMOFs), as cargo nanocarriers, have increasingly attracted the attention of scientists and biotechnologists during the past decade, in parallel with the evolution in the use of porous nanomaterials in biomedicine. Compared to other nanoparticle-based delivery systems, such as porous nanosilica, nanomicelles, and dendrimer-encapsulated nanoparticles, NMOFs are more flexible, have a higher biodegradability potential, and can be more easily functionalized to meet the required level of host-guest interactions, while preserving a larger and fully adjustable pore window in most cases. Due to these unique properties, NMOFs have the potential to carry anticancer cargos. In contrast to almost all porous materials, MOFs can be synthesized in diverse morphologies, including spherical, ellipsoidal, cubic, hexagonal, and octahedral, which facilitates the acceptance of various drugs and genes.

Natural Polymers Decorated MOF-MXene Nanocarriers for Co-delivery of Doxorubicin/pCRISPR

A one-pot and facile method with assistance of high gravity was applied for the synthesis of inorganic two-dimensional MOF-5 embedded MXene nanostructures. The innovative inorganic MXene/MOF-5 nanostructure was applied in co-delivery of drug and gene, and to increase its bioavailability and interaction with the pCRISPR, the nanomaterial was coated with alginate and chitosan. The polymer-coated nanosystems were fully characterized, and the sustained DOX delivery and comprehensive cytotoxicity studies were conducted on the HEK-293, PC12, HepG2, and HeLa cell lines, demonstrating acceptable and excellent cell viability at both very low (0.1 μg.mL^-1) and high (10 μg·mL^-1) concentrations. The chitosan-coated nanocarriers showed superior relative cell viability compared to others, more than 60% on average of relative cell viability in all of the cell lines. Then, alginate-coated nanocarriers ranked at second place on the higher relative cell viability, more than 50% on average for all of the cell lines. Also, MTT results showed a complete dose-dependence, and by increasing the time of treatment from 24 to 72 h, the relative cell viability decreased by a meaningful slope; however, this decrease was optimized by coating the nanocarrier with chitosan and alginate. The nanosystems were also tagged with pCRISPR to analyze the potential application in the co-delivery of drug/gene. CLSM images of the HEK-293 and HeLa cell lines unveiled successful delivery of pCRISPR into the cells, and the enhanced green fluorescent protein (EGFP) reached up to ca. 26% for the HeLa cell line. Also, a considerable drug payload of 35.7% was achieved, which would be because of the interactions between the nanocarrier and the doxorubicin. In this unprecedented report pertaining to the synthesis of MXene assisted by a MOF and high-gravity technique, the methodology and the optimized ensuing MXene/MOF-5 nanosystems can be further developed for the co-delivery of drug/gene in animal models.

A multi-responsive MOF-based fluorescent probe for detecting Fe3+, Cr2O72− and acetylacetone

A novel ZnII-based MOF can selectively and sensitively recognize Fe3+, Cr2O72− and acetylacetone, simultaneously.