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Cell cycle population distribution (percentage of cells, %) after treatment for 24 h with PEG2k-b-dxDAP aggregates obtained by microfluidics (A, Table 3) and with a polymer concentration adjusted to 0.4 mg mL −1 .
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Hybrid linear–dendritic block copolymers (LDBCs) having dendrons with a precise number of peripheral groups that are able to supramolecular bind functional moieties are challenging materials as versatile polymeric platforms for the preparation of functional polymeric nanocarriers. PEG2k-b-dxDAP LDBCs that are based on polyethylene glycol (PEG) as h...
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... The structure of the PO and PB is shown in Scheme 1. We built the PO dendrimer based on the dendrimer synthetic method that we reported previously [33,45] and modified the 2,2-Bis(hydroxymethyl)propionic acid (bis-MPA) through the ester bonds [46] (Scheme S1, Supporting Information). The PO and PB were purified by flash chromatographic column (SepaBean® U200, SANTAI). ...
Nanocarriers have great potential to enhance drug delivery efficiency and therapeutic effect for various cancers. However, premature drug leakage and non-specific targeting still limit the delivery efficiency. Here, we present a smart on-demand targeting nanotheranostic system ([email protected]) with stimuli-responsive releasing property to improve the delivery efficiency for ovarian cancer. This delivery system prevents premature drug leakage via boronate ester linkages and shields the targeting moieties (phenylboronic acid) from non-specific binding when circulating in the blood. The [email protected] would release the tumor-targeting payload (PB) in response to the tumor microenvironment. Then, PB was able to target the overexpressed sialic acids on tumor cells. The significant improvement of delivery efficiency was demonstrated in vivo by a significantly enhanced signal in near-infrared-fluorescence (NIRF)/magnetic-resonance (MR) imaging (5-fold higher) and a remarkable photo-thermal therapeutic effect (complete cure rate (CCR) up to 80%). Furthermore, due to the on-demand targeting and stimuli-responsive releasing strategy, this nanotheranostic system shows a greater delivery efficiency even than the active-targeting small molecules or control nanoformulations. We believe this delicate design has great potential to develop novel drug nanoformulation.
... The obtained polymersomes, therefore, were based on units of a solvophilic PEG-block linked to a solvophilic dendritic polyester that was attached to the solvophobic aliphatic block also linked to a solvophobic azobenzene block. It was found that polymersomes were formed with a long enough solvophobic aliphatic block length at a lower dendritic generation number [110], as reported by other authors, such as Chandrasiri [111] and Abad et al. [112]. ...
Polymersomes are biomimetic cell membrane-like model structures that are self-assembled stepwise from amphiphilic copolymers. These polymeric (nano)carriers have gained the scientific community’s attention due to their biocompatibility, versatility, and higher stability than liposomes. Their tunable properties, such as composition, size, shape, and surface functional groups, extend encapsulation possibilities to either hydrophilic or hydrophobic cargoes (or both) and their site-specific delivery. Besides, polymersomes can disassemble in response to different stimuli, including light, for controlling the “on-demand” release of cargo that may also respond to light as photosensitizers and plasmonic nanostructures. Thus, polymersomes can be spatiotemporally stimulated by light of a wide wavelength range, whose exogenous response may activate light-stimulable moieties, enhance the drug efficacy, decrease side effects, and, thus, be broadly employed in photoinduced therapy. This review describes current light-responsive polymersomes evaluated for anticancer therapy. It includes light-activable moieties’ features and polymersomes’ composition and release behavior, focusing on recent advances and applications in cancer therapy, current trends, and photosensitive polymersomes’ perspectives.
... Macromolecules comprised of dendritic structures have been widely utilized in a variety of different areas both in academia and industry [1][2][3]. The introduction of, normally, randomly dispersed dendritic units with multi-functionalities along the polymeric backbone is key to the unique physiochemical properties they possess [4,5]. In comparison with their linear counterparts, highly branched materials exhibit low viscosity and enhanced solubility, and the higher density branches can optionally possess functional groups to allow further modification [6]. ...
... We reasoned two factors could be used to decrease sensitivity to steric issues: (i) move the locus of reaction further away from the silicone backbone by use of vinyl groups on the backbone instead of SiH groups, [19]; (B) The synthesis of dendrite-branched polysiloxanes [21]. The Piers-Rubinsztajn reaction (PR), which provides a facile route to structurally complex silicones, involves the reaction of hydrosilanes with the strong Lewis acid catalyst B(C 6 F 5 ) 3 in the presence of appropriate nucleophiles [22]. We previously reported the use of this process combined with hydrosilylation reactions to synthesize precise silicone dendrimers with molar mass of up to 13,500 g mol −1 using iterative reactions of PR and platinum-catalyzed hydrosilylation in the absence of degradation (Figure 2A,C) [23]. ...
... Polymers 2021, 13, x FOR PEER REVIEW 13 of 17 densities, GPC can underestimate molecular weight because the behavior of linear calibrating polymers is quite different from these highly branched polymers, which can take up a globular structure [25,36]. The iterative PR/hydrosilylation process can be repeated with compound P-Vi-14-OR 3 , for example, using vinyltetramethyldisiloxane to give alkoxysilane-free compound P-Vi-14-OVi 3 . The net effect is to convert single pendent vinyl groups in compound P-Vi-14 into trivinyl-functional branches in compound P-Vi-14-OVi 3 . ...
Branched silicones possess interesting properties as oils, including their viscoelastic behavior, or as precursors to controlled networks. However, highly branched silicone polymers are difficult to form reliably using a “grafting to” strategy because functional groups may be bunched together preventing complete conversion for steric reasons. We report the synthesis of vinyl-functional highly branched silicone polymers based, at their core, on the ability to spatially locate functional vinyl groups along a silicone backbone at the desired frequency. Macromonomers were created and then polymerized using the Piers–Rubinsztajn reaction with dialkoxyvinylsilanes and telechelic HSi-silicones; molecular weights of the polymerized macromonomers were controlled by the ratio of the two reagents. The vinyl groups were subjected to iterative (two steps, one pot) hydrosilylation with alkoxysilane and Piers–Rubinsztajn reactions, leading to high molecular weight, highly branched silicones after one or two iterations. The vinyl-functional products can optionally be converted to phenyl/methyl-modified branched oils or elastomers.
Here we report on the synthesis of dumbbell-like linear-dendritic copolymers based on polyethylene glycols bearing aspartic dendrons with terminal amino and carboxylic groups. The ionic complexes of such oppositely charged...
Self-assemblies containing the nucleobase analogue 2,6-diacylaminopyridine (DAP) have been successfully prepared for the first time by aqueous seeded RAFT polymerization in high concentrations. For this purpose, a diblock copolymer containing poly(ethylene glycol) (PEG) and DAP polymethacrylate blocks was used as a macro-chain-transfer agent (PEG124-b-PDAP9-CTA) for the polymerization of 2-hydroxypropyl methacrylate (HPMA) in water. From the systematic variation of the degree of polymerization and solid concentration, a phase diagram has been generated that correlates both variables with the morphologies of this new system. Self-assemblies have been characterized by TEM and DLS, observing morphologies from low to high order (from spherical micelles to worms and to vesicles). Self-assembly morphologies are stable for almost a year, except in the case of worms that turn into spherical micelles after a few weeks. In addition, H-bonding supramolecular functionalization of the DAP repeating units during aqueous seeded RAFT polymerization has been examined by functionalization with a cross-linker with four thymine groups. Finally, the loading and the subsequent release of Nile Red have been proven in both supramolecular cross-linked and non-cross-linked self-assemblies.
Novel nanocarriers such as multifunctional nanoparticles (NPs) have recently attracted attention due to their various applications, specifically in medicine and treatment. However, it is vital that these particles be synthesized with meticulous control of different structural, chemical, and physical properties. In response to this demand, microfluidic (MF) technology as a reliable procedure can provide promising results in the development of desired NPs and efficient drug delivery systems. By controlling the flow rates of multiphase fluids and conditions of chemical reactions, MF technology enables the fabrication of uniform and highly stable particles with enhanced surfaces, higher encapsulation efficiency, and controlled release of therapeutic agents compared with conventional bulk methods. This review article investigates the MF‐based methods utilized in the synthesis of NPs and their advantages in developing novel drug delivery systems. It also provides a comprehensive comparison with conventional methods from a different point of view, emphasizing a novel category of nanocarriers’ critical characteristics. In addition, a summary of the most recent representative works on NPs fabrication by MF procedures is presented, and their potential and applications in drug delivery are discussed.
This Special Issue State-of-the-Art on Polymer Science and Technology in Spain is comprised of a collection of 42 publications/contributions related to very different topics undertaken by the numerous research groups working in Spain in Polymer Science and Technology. This monograph collects the contributions of more than 200 different authors from 24 different national Institutions (>30 different centers/departments) from Universities and CSIC centers distributed throughout the whole of Spain. Two-thirds of the contributions to this Special Issue arise from Institutional collaborations, half of which are international collaborations with European research groups and the other half with other international research groups outside Europe including China, Australia or United States of America among others. This brief overview communication provides a general overview of the research lines in Polymer Science and Technology covered in Spain and show most of the representative polymer groups and their distribution throughout Spain. Most of Spanish polymer groups belong to the Grupo Especializado de Polímeros (GEP) being part of the European Polymer Federation (EPF). It also shows how Spanish science about polymers is positioned at European level.
