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A multiwalled carbon nanotube (MWNT)-based drug delivery system was developed by covalently combining carbon nanotubes with the antitumor agent 10-hydroxycamptothecin (HCPT) using hydrophilic diaminotriethylene glycol as the spacer between nanotube and drug moieties. The surface functionalizations of the nanotube were carried out by enrichment of carboxylic groups with optimized oxidization treatment, followed by covalently linking hydrophilic diaminotriethylene glycol via amidation reaction, and then HCPT was chemically attached to carbon nanotubes through a cleavable ester linkage. It is demonstrated that the obtained MWNT-HCPT conjugates are superior in antitumor activity both in vitro and in vivo to clinical HCPT formulation. In vivo single photon emission computed tomography (SPECT) imaging and ex vivo gamma scintillation counting analyses reveal that MWNT-HCPT conjugates have relatively long blood circulation and high drug accumulation in the tumor site. These properties together with the enhanced cell uptake and multivalent presentation of HCPT on a single nanotube benefit substantially the antitumor effects and would boost significantly the applications of carbon nanotubes in the biomedicine field.

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Today, hybrid manufacturing technology has drawn significant interests from both academia and industry due to the capability to make products in a more efficient and productive way. Although there is no specific consensus on the definition of the term 'hybrid processes', researchers have explored a number of approaches to combine different manufacturing processes with the similar objectives of improving surface integrity, increasing material removal rate, reducing tool wear, reducing production time and extending application areas. Thus, hybrid processes open up new opportunities and applications for manufacturing various components which are not able to be produced economically by processes on their own. This review paper starts with the classification of current manufacturing processes based on processes being defined as additive, subtractive, transformative, joining and dividing. Definitions of hybrid processes from other researchers in the literature are then introduced. The major part of this paper reviews existing hybrid processes reported over the past two decades. Finally, this paper attempts to propose possible definitions of hybrid processes along with the authors' classification, followed by discussion of their developments, limitations and future research needs.

A molecular brush based on conjugated polyelectrolyte (CPE) grafted with dense poly(ethylene glycol) (PEG) chains was successfully complexed with an anticancer agent, cisplatin, to form cisplatin-loaded nanoparticles (CPE-PEG-Pt). The obtained nanoparticles have high far-red/near-infrared fluorescence and are able to release the drug in a continuous and slow manner. These nanoparticles have not only been used to visualize HepG2 cancer cells, but also served as an in vivo fluorescent imaging probe that simultaneously tracks the in vivo drug distribution in nude mice upon intravenous administration.

Modern fluorescence imaging techniques have become essential tools to provide crucial insights in understanding complicated biological processes. Because of their unique optical properties (e.g., excellent photostability, high brightness, broad absorption, and narrow emission), inorganic quantum dots (QDs) have attracted great interest in fluorescence bioimaging. However, the intrinsic toxicity resulting from their heavy-metal components as well as the low-pH-induced fluorescence-quenching phenomenon has motivated researchers to explore novel fluorescent probes with the goal of overcoming these obstacles. In this work, we report the synthesis of two groups of organic fluorescent dots with aggregation-induced emission (AIE) characteristics that have a large Stokes shift, ensuring distinct emission spectra (green and red fluorescence) under singlewavelength excitation. Single-particle imaging experiments revealed the unique optical properties of such AIE dots, which outperform their commercially available inorganic QD counterpart in physical stability and brightness. Upon functionalization with a cell-penetrating peptide, the strong absorptivity, high brightness, good cellular-internalization efficiency, and low cytotoxicity of both the green and red AIE dots allow for the simultaneous discrimination of different populations of cancer cells both in culture medium and animal organs, which is of high importance for understanding cellular interactions during cancer metastasis. Considering the versatile surface functionalities endowed by the encapsulation matrix, a series of organic AIE dots with customized properties will provide prospective platforms to satisfy multifarious bioimaging tasks in the near future.

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