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A novel type of self-fluorescent unimolecular micelle nanoparticle (NP) formed by multi-arm star amphiphilic block copolymer, Boltron® H40 (H40, a 4th generation hyperbranched polymer)-biodegradable photo-luminescent polymer (BPLP)-poly(ethylene glycol) (PEG) conjugated with cRGD peptide (i.e., H40-BPLP-PEG-cRGD) was designed, synthesized, and characterized. The hydrophobic BPLP segment was self-fluorescent, thereby making the unimolecular micelle NP self-fluorescent. cRGD peptides, which can effectively target αvβ3 integrin-expressing tumor neovasculature and tumor cells, were selectively conjugated onto the surface of the micelles to offer active tumor-targeting ability. This unique self-fluorescent unimolecular micelle exhibited excellent photostability and low cytotoxicity, making it an attractive bioimaging probe for NP tracking for a variety of microscopy techniques including fluorescent microscopy, confocal laser scanning microscopy (CLSM), and two-photon microscopy. Moreover, this self-fluorescent unimolecular micelle NP also demonstrated excellent stability in aqueous solutions due to its covalent nature, high drug loading level, pH-controlled drug release, and passive and active tumor-targeting abilities, thereby making it a promising nanoplatform for targeted cancer theranostics.

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A three-dimensional structure consisting of poly(ε-caprolactone) (PCL) nanofibers covered by periodically spaced PCL crystal lamellae, a self-induced nanohybrid shish-kebab (SINSK) structure, was created using electrospinning followed by a self-induced crystallization. The resulting structure that resembles the nanotopography of natural collagen nanofibrils in the extracellular matrix (ECM) of human tissues could serve as a tissue engineering scaffold. The formation mechanism of the self-induced shish-kebab structure was investigated with real-time observation of the crystallization process. Electrospun polylactic acid (PLA)/PCL nanofibers were also employed as shish elements to study the effects of different shish materials. The results show that the geometric dimensions of the shish-kebabs are highly related to the initial concentration of PCL solution. The shish material played an important role in the creation of shish-kebab structure. Cell assays with NIH 3T3 ECACC fibroblasts suggest that the nanotopography of the nanofiber surface with kebab crystals that mimic collagen fibrils facilitated the cell attachment and spreading of 3T3 fibroblasts cells.