Carbon dots (C-dots), since their first discovery in 2004 by Scrivens et al. during purification of single-walled carbon nanotubes, have gradually become a rising star in the fluorescent nanoparticles family, due to their strong fluorescence, resistance to photobleaching, low toxicity, along with their abundant and inexpensive nature. In the past decade, the procedures for preparing C-dots have become increasingly versatile and facile, and their applications are being extended to a growing number of fields. In this review, we focused on introducing the biological applications of C-dots, hoping to expedite their translation to the clinic. 相似文献
CP-PEI-FA was prepared as an effective vector for in vitro and in vivo tumor-targeted gene delivery. The structures of the polymers were characterized, and their DNA condensation capability, particle sizes, zeta potentials, cytotoxicity and in vitro/in vivo transfection were examined. The cytotoxicity of CP-PEI-FA was significantly lower than that of PEI 25 kDa and close to that of PEI 1200. The in vitro transfection of CP-PEI-FA was tested in C6 and HeLa cells (FR-positive cells) and A549 cells (FR-negative cells). CP-PEI-FA showed a high targeting specificity and good gene transfection efficiency in FR-positive cells. These results indicate that CP-PEI-FA is a safe and effective polyplex-forming agent for both in vitro and in vivo transfection of plasmid DNA. 相似文献
Block copolymer micelles with bactericidal properties were designed to deactivate pathogens such as E. coli bacteria. The micelles of PS‐b‐PAA and PS‐b‐P4VP block copolymers were loaded with biocides TCMTB or TCN up to 20 or 30 wt.‐%, depending on the type of antibacterial agent. Bacteria were exposed to loaded micelles and bacterial deactivation was evaluated. The micelles loaded with TCN are bactericidal; bacteria are killed in less than two minutes of exposure. The most likely interpretation of the data is that the biocide is transferred to the bacteria by repeated micelle/bacteria contacts, and not via the solution.
Three kinds of head‐tail‐type block copolymers composed of polyamidoamine (PAMAM) dendron heads and poly(L ‐lysine) (PLL) tail blocks (PAMAM dendron‐PLL), having PAMAM dendrons with different generations (G2.5‐PLL, G3.5‐PLL and G4.5‐PLL) were synthesized. Some of the dendron heads were located at polyplex surface, and G2.5‐PLL and G3.5‐PLL could form small polyplexes (less than 150 nm in size). G2.5‐PLL and G3.5‐PLL polyplexes were taken up into the cells more effectively. PAMAM dendron‐PLL that had a larger dendron head could show a more‐effective buffering effect. The in vitro performance of the PAMAM dendron‐PLL polyplexes was controlled by the balance of cellular uptake and endosomal escape by a buffering effect.
This review presents a simple introduction on the unique properties and general synthesis of quantum dots (QDs) in which we lay emphasis on the optical applications in the biological system. The detection of biological molecules such as DNA, protein and enzyme, the cell-based analysis and in vivo animal imaging are mainly discussed. 相似文献
The biochemical cues and topographical architecture of the extracellular environment extensively influence ES cell fate. The microenvironment surrounding the developing embryo presents these instructive cues in a complex and interactive manner in order to guide cell fate decisions. Current stem cell research aims to reconstruct this multifaceted embryonic niche to recapitulate development in vitro. This review focuses on 2D and 3D differentiation niches created from natural and synthetic biomaterials to guide the differentiation of ES cells toward specific lineages. Biomaterials engineered to present specific physical constraints are also reviewed for their role in differentiation. 相似文献