We present a facile approach to make aptamer‐conjugated FRET (fluorescent resonance energy transfer) nanoflowers (NFs) through rolling circle replication for multiplexed cellular imaging and traceable targeted drug delivery. The NFs can exhibit multi‐fluorescence emissions by a single‐wavelength excitation as a result of the DNA matrix covalently incorporated with three dye molecules able to perform FRET. Compared with the conventional DNA nanostructure assembly, NF assembly is independent of template sequences, avoiding the otherwise complicated design of DNA building blocks assembled into nanostructures by base‐pairing. The NFs were uniform and exhibited high fluorescence intensity and excellent photostability. Combined with the ability of traceable targeted drug delivery, these colorful DNA NFs provide a novel system for applications in multiplex fluorescent cellular imaging, effective screening of drugs, and therapeutic protocol development. 相似文献
Drug delivery systems have been widely developed for enhancing target activity and improving drug functions.Liposomes,high-molecular polymer,gold nanoparticles and carbon nanomaterials,etc.,are all the candidates of drug carriers.However,immunotoxicity,heterogeneity and low solubility generally exist and hamper their applications.As a kind of biological materials,DNA has its unique advantages in biomedical applications,including excellent biological compatibility and programmability.DNA nanostructures have been proved to possess high cellular uptake efficiency,which sheds new light on DNA-based drug delivery system.In this review,we summarize the influence factors of DNA nanostructure internalization efficiency,including cell lines,and the size and the shape of DNA nanoparticles.Uniformity of DNA nanostructures in appearance and properties ensures the stability in research,which makes DNA carriers stand out from other nanomaterials.Next,we focus on the functionalization of DNA carriers,which endows DNA nanostructures with the potential to construct integrated drug delivery platforms.We also discuss the internalization pathways of DNA nanostructures and their fate in cells.The deeply understanding about the endocytic pathways provides new sight for the further design strategy on changing the transportation routes of DNA carriers in cells.Finally,the challenges in further applications are discussed,and suggestions are proposed. 相似文献
Gd doped hollow nanoscale coordination polymers with multimodal imaging capabilities were synthesized by solvothermal method and further coated by silica layer. The \begin{document}$in$\end{document}\begin{document}$vitro$\end{document} tests demonstrated uncoated and silica-coated nanoprobes exhibit longitudinal relaxivities (\begin{document}$r_1$\end{document}) of 7.38 and 13.57 (mmol/L)\begin{document}$^{-1}$\end{document}\begin{document}$\cdot$\end{document}s\begin{document}$^{-1}$\end{document}, and transverse relaxivities (\begin{document}$r_2$\end{document}) of 180.6 and 304.8 (mmol/L)\begin{document}$^{-1}$\end{document}\begin{document}$\cdot$\end{document}s\begin{document}$^{-1}$\end{document}, showing fairly good dual T1&T2 contrast effects, and it also emits excellent multicolor fluorescence under laser beams of various wavelengths. With the combination of magnetic resonance imaging (MRI) (both T1 and T2) and fluorescence optical imaging (FOI), the nanoprobes could correlate preoperative diagnosis with intraoperative pathology. Furthermore, it also exhibits high drug loading capacity of 1166 mg/g and encapsulation efficiency of 83.29%, which makes it a potential platform as drug carriers. The MTT assay demonstrates the moderate toxicity of the NPs, and after the silica coating process, not only the MRI contrast effects but also the biocompatibility have been enhanced. The versatility of the highly integrated systems can make up for the limitations of each imaging modality and exhibit great potentials for cancer theranostics. 相似文献
Cationic polymers have been chemically modified with a variety of targeting molecules such as peptides, proteins, antibodies, sugars and vitamins for targeted delivery of nucleic acid drugs to specific cells. Stimuli‐sensitive polymers exhibiting different size, charge and conformation in response to physiological signals from specific cells have also been utilized for targeted delivery. To achieve target‐specific delivery of nucleic acids, conjugation chemistry is critical to produce stable nanosized polyplexes tethered with cell‐recognizable ligands for facile cellular uptake via a receptor‐mediated endocytic pathway. In this review, synthetic strategies of functional cationic polymers with various targeting ligands are presented.
In this study, we have reported novel thermosensitive nanoparticles formulated by an emulsion-solvent evaporation technique using acetaminophen (AAP) as a model drug. The high entrapment efficiency of nanoparticles was 68.56%, particle size about 240.6 nm and zeta potential ?27 mV. Furthermore, the drug release was also investigated both at 37°C and 42°C, respectively. The goal of our study was to obtain a targeted drug delivery system, exploiting the temperature-sensitive behavior. In contrary to normal temperature (37°C), the release rate of AAP was found to noticeably increase at high temperature (42°C) with a larger cumulative amount of drug released. In this way, it would lead to production of nanoparticles having a high thermosensitive behavior on drug release. Thus, this new strategy has the potential to control drug release at the diseased site for targeted drug delivery system (TDDS) with positive temperature-controlled. 相似文献
Carriers that can afford tunable physical and structural changes are envisioned to address critical issues in controlled drug delivery applications. Herein, photo‐responsive conjugated polymer nanoparticles (CPNs) functionalized with donor–acceptor Stenhouse adduct (DASA) and folic acid units for controlled drug delivery and imaging are reported. Upon visible‐light (λ=550 nm) irradiation, CPNs simultaneously undergo structure, color, and polarity changes that release encapsulated drugs into the cells. The backbone of CPNs favors FRET to DASA units boosting their fluorescence. Notably, drug‐loaded CPNs exhibit excellent biocompatibility in the dark, indicating perfect control of the light trigger over drug release. Delivery of both hydrophilic and hydrophobic drugs with good loading efficiency was demonstrated. This strategy enables remotely controlled drug delivery with visible‐light irradiation, which sets an example for designing delivery vehicles for non‐invasive therapeutics. 相似文献
A new series of MnII coordination polymers, namely, [{Mn(L)(H2O)2} ? 2 Nap]∞ ( CP1 ), [{Mn(L)(Ibu)2(H2O)2}]∞ ( CP2 ), [{Mn(L)(Flr)2(H2O)2}]∞ ( CP3 ), [{Mn(L)(Ind)2(H2O)2} ? H2O]∞ ( CP4 ), [{Mn2(L)2(μ‐Flu)4(H2O)} ? L]∞ ( CP5 ), [{Mn2(L)2(μ‐Tol)4(H2O)2}]∞ ( CP6) and [{Mn2(L)2(μ‐Mef)4(H2O)2}]∞ ( CP7 ) (Nap=naproxen, Ibu=ibuprofen, Flr=flurbiprofen, Ind=indometacin, Flu=flufenamic acid, Tol=tolfenamic acid and Mef=mefenamic acid) derived from various non‐steroidal anti‐inflammatory drugs (NSAIDs) and the organic linker 1,2‐bis(4‐pyridyl)ethylene (L) have been synthesized with the aim of being used for cell imaging and drug delivery. Single‐crystal X‐ray diffraction (SXRD) studies revealed that the NSAID molecules were part of the coordination polymeric network either through coordination to the metal center (in the majority of the cases) or through hydrogen bonding. Remarkably, all the MnII coordination polymers were found to be soluble in DMSO, thereby making them particularly suitable for the desired biological applications. Two of the coordination polymers (namely, CP1 and CP3 ) reported herein, were found to be photoluminescent both in the solid as well as in the solution state. Subsequent experiments (namely, MTT (3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide), and PGE2 (prostaglandin E2) assays) established their biocompatibility and anti‐inflammatory response. In vitro studies by using a macrophage cell line (i.e., RAW 264.7) revealed that both CP1 and CP3 were excellent cell imaging agents. Finally, biodegradability studies under simulated physiological conditions in phosphate‐buffered saline (PBS) at pH 7.6 showed that slow and sustained release of the corresponding NSAID was indeed possible from both CP1 and CP3 . 相似文献
Here we present a novel strategy for specific cellular targeting of polymeric nanocontainers by using self-assembly of block copolymers consisting of either Polydimethoxysiloxane-b-Polymethyloxazoline-b-Polydimethoxysiloxane (PDMS-b-PMOXA-b-PDMS) or functionalized PDMS-b-PMOXA-b-PDMS. Covalent functionalization of the above copolymer was accomplished using either the fluorescent dye sulforhodamine B or a poly-guanosin ligand, the latter by using the Huisgen 1,3-dipolar cycloaddition. The success of the covalent modification of the block copolymer has been determined by studying functionalized sulforhodamine B by NMR and fluorescence correlation spectroscopy. The covalent click chemistry approach leads to efficiently functionalized polymeric nanocontainers which enables specific uptake by activated macrophages overexpressing the scavenger receptor A1. 相似文献
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