An effective intracellular gene silencing strategy based on acoustically propelled nanowires modified with an interfering RNA's (siRNA) payload is described. The gold nanowires (AuNW) are wrapped with a Rolling Circle Amplification (RCA) DNA strand, which serves to anchor the siRNA therapy. The ultrasound (US)-powered propulsion of the AuNW leads to fast internalization and rapid intracellular movement and hence to an accelerated siRNA delivery and silencing response. To optimize the micromotor gene silencing procedure, the influence of motion, time, and siRNA dosage was investigated, leading up to a 94% silencing after few minutes treatment with US-propelled siRNA-AuNWs, and to a dramatic (∼13-fold) improvement in the silencing response compared to the static modified nanowires. The ability of the nanomotor-based method for gene silencing has been demonstrated by measuring the GFP silencing response in two different cell lines (HEK-293 and MCF-7) and using detailed control experiments. The viability of the cells after the nanomotors treatment was examined using the MCF-7 cancer cell line. The use of DNA structures carried by the US-propelled nanomotors for gene silencing represents an efficient tool that addresses the challenges associated with RNA transportation and intracellular delivery. Future implementation of nanomachines in gene therapy applications can be expanded into a co-delivery platform for therapeutics.
Nanomedicine has been growing exponentially due to its enhanced drug targeting and reduced drug toxicity. It uses the interactions where nanotechnological components and biological systems communicate with each other to facilitate the delivery performance. At this scale, the physiochemical properties of delivery systems strongly affect their capacities. Among current delivery systems, DNA nanotechnology shows many advantages because of its unprecedented engineering abilities. Through molecular recognition, DNA nanotechnology can be used to construct a variety of nanostructures with precisely controllable size, shape, and surface chemistry, which can be appreciated in the delivery process. In this review, different approaches that are currently used for the construction of DNA nanostructures are reported. Further, the utilization of these DNA nanostructures with the well-defined parameters for the precise control in drug delivery and gene therapy is discussed.
Amino acid-based poly(ester urea)s (PEU) are emerging as a new class of degradable polymers that have shown promise in regenerative medicine applications. Herein, we report the synthesis of PEUs carrying pendent "clickable" groups on modified tyrosine amino acids. The pendent species include alkyne, azide, alkene, tyrosine−phenol, and ketone groups. PEUs with M w exceeding to 100K Da were obtained via interfacial polycondensation methods, and the concentration of pendent groups was varied using a copolymerization strategy. The incorporation of derivatizable functionalities is demonstrated using 1 H NMR and UV−vis spectroscopy methods. Electrospinning was used to fabricate PEU nanofibers with a diameters ranging from 350 to 500 nm. The nanofiber matricies possess mechanical strengths suitable for tissue engineering (Young's modulus: 300 ± 45 MPa; tensile stress: 8.5 ± 1.2 MPa). A series of bioactive peptides and fluorescent molecules were conjugated to the surface of the nanofibers following electrospinning using bio-orthogonal reactions in aqueous media. The ability to derivatize PEUs with biological molecules using translationally relevant chemical methods will significantly expand their use in vitro and in vivo.
A series of low bandgap semi-random
copolymers incorporating various
ratios of two acceptor unitsthienothiadiazole and benzothiadiazolewere
synthesized by Pd-catalyzed Stille coupling. The polymer films exhibited
broad and intense absorption spectra, covering the spectral range
from 350 nm up to 1240 nm. The optical bandgaps and HOMO levels of
the polymers were calculated from ultraviolet–visible spectroscopy
and cyclic voltammetry measurements, respectively. By changing the
ratio of the two acceptor monomers, the HOMO levels of the polymers
were tuned from −4.42 to −5.28 eV and the optical bandgaps
were varied from 1.00 to 1.14 eV. The results indicate our approach
could be applied to the design and preparation of conjugated polymers
with specifically desired energy levels and bandgaps for photovoltaic
applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.