1. Optimizing the circulating tumor cells capture efficiency of magnetic
    nanogels by transferrin decoration
    C. Biglione, J. Bergueiro, M. Asadian-Birjand, C. Weise, V. Khobragade, G. Chate, M. Dongare, J. Khandare, M. Strumia, M. Calderón*
    Submitted to Polymers
  2. Enhanced topical delivery of dexamethasone by β-cyclodextrin decorated thermoresponsive nanogels

     2018, 10, 469-479

    Highly hydrophilic, responsive nanogels are attractive as potential systems for the topical delivery of bioactives encapsulated in their three-dimensional polymeric scaffold. Yet, these drug carrier systems suffer from drawbacks for efficient delivery of hydrophobic drugs. Addressing this, β-cyclodextrin (βCD) could be successfully introduced into the drug carrier systems by exploiting its unique affinity toward dexamethasone (DXM) as well as its role as topical penetration enhancer.
  3. Unexpected Chiro-Thermoresponsive Behaviour of Helical Poly(phenylacetylene)s Bearing Elastin-Based Side-Chains
    S. Arias, F. Freire,* M. Calderón* and J. Bergueiro*
    Angewandte Chemie Int. Ed.
    2017, 56, 11420-11425

    Feel the heat: The dynamic macromolecular helical structure of a poly(phenylacetylene) can be used to alter the thermoresponsive properties of an elastin-based side-chain polymer. The polymeric helical conformation changes the expected lower critical solution temperature thermoresponsiveness to an upper critical solution temperature behavior.
  4. Dendritic polyglycerol and N-isopropylacrylamide based thermoresponsive nanogels as smart carriers for controlled delivery of drugs through the hair follicle
    F. F. Sahle, M. Giulbuldagian, J. Bergueiro, J. Lademann and M. Calderon*
    Nanoscale 2017, 9, 172-182

    Nanoparticles with a size of several hundred nanometers can effectively penetrate into the hair follicles and may serve as depots for controlled drug delivery.  An efficient way for drug delivery through the follicular route is to employ nanoparticles that can release the drug close to the target structure upon exposure to some external or internal stimuli.
  5. Near Infrared Dye Conjugated Nanogels for Combined Photodynamic and Photothermal Therapies
    M. Asadian-Birjand, J. Bergueiro, S. Wedepohl and M. Calderon*
    Macromol. Biosci. 2016, 16, 1432-1441

    Cyanin dye conjugated nanogels are designed and evaluated in vitro as a polyvalent platform for photothermal and photodynamic therapy. Along with their biocompatible profile, their near infrared light-to-heat transducing property, and their imaging ability, they offer possibilities for their further use as a theranostic agent in vivo.


    Highlighted in Advanced Science News

  6. Transferrin Decorated Thermoresponsive Nanogels as Magnetic Trap Devices for Circulating Tumor Cells
    M. Asadian-Birjand, C. Biglione, J. Bergueiro, A. Cappelletti, C. Rahane, G. Chate, J. Khandare, B. Klemke, M. C. Strumia* and M. Calderon*
    Macromol. Rapid Comm. 2016, 37, 439-445

    A thermoresponsive nanogel formed by linear thermoresponsive polyglycerol and magnetic nanoparticles is evaluated as a magnetic trap for circulating tumor cells. Transferrin is employed as targeting moiety. It is shown that the longitude of the linker used in the protein to nanogel ligation has a big impact on the cell sorting properties.

    Highlighted in Advanced Science News

  7. Chiral Nanostructures from Helical Copolymer–Metal Complexes: Tunable Cation-p Interactions and Sergeants and Soldiers Effect
    S. Arias J. Bergueiro, E. Quiñoa, R. Riguera and F. Freire*
    Small 2015, 12, 238-244
    (DOI:10.1002/smll.201502276 )

    Mirror image nanostructures from a single helical copolymer–metal complex can be obtained by the presence of a certain amount of a donor cosolvent, which activate/deactivate cation–π supramolecular interactions on the chiral monomers of the copolymer. Those structural changes are transferred to the rest of the polymer chain inducing a selective P or M helical sense through the Sergeants and Soldiers Effect.


    Highlighted in Advances in Engineering

  8. Engineering Thermoresponsive Polyether-based Nanogels for Temperature Dependent Skin Penetration
    M. Asadian-Birjand, J. Bergueiro, F. Rancan, J. C. Cuggino, R. –C. Mutihac, K. Achazi, J. Dernedde, U. Blume-Peytayi, A. Vogt and M. Calderon*
    Pol. Chem. 2015, 6, 5827-5831

    Highly biocompatible thermoresponsive nanogels (tNGs) based on oligo ethylene glycol (OEG) as thermoresponsive unit and dendritic polyglycerol (dPG) as cross-linker, were precisely engineered in terms of size and volume phase transition temperature (VPTT). Preliminary uptake studies into human skin were realized to show the temperature-dependent internalization behavior of these systems.
  9. Stimuli-Responsive Nanogel Composites and their Application in Nanomedicine
    M. Molina, M. Asadian-Birjand, J. Balach, J. Bergueiro, E. Miceli and M. Calderon*
    Chem. Soc. Rev. 2015, 44, 6161-6186
    (DOI:10.1039/C5CS00199D )

    Nanogels are nanosized crosslinked polymer networks capable of absorbing large quantities of water. Specifically, smart nanogels are interesting because of their ability to respond to biomedically relevant changes like pH, temperature, etc. In the last few decades, hybrid nanogels or composites have been developed to overcome the ever increasing demand for new materials in this field. In this context, a hybrid refers to nanogels combined with different polymers and/or with nanoparticles such as plasmonic, magnetic, and carbonaceous nanoparticles, among others. Research activities are focused nowadays on using multifunctional hybrid nanogels in nanomedicine, not only as drug carriers but also as imaging and theranostic agents. In this review, we will describe nanogels, particularly in the form of composites or hybrids applied in nanomedicine.
  10. Aplicaciones Biomédicas de Nanogeles Dendríticos Termosensibles
    M. Molina, J. Bergueiro, A. Sousa-Herves and M. Calderon
    Rev. Iber. Polímeros 2015, 16, 164-172
  11. Thermoresponsive Nanodevices in Biomedical Applications
    J. Bergueiro and M. Calderon*
    Macomol. Biosci. 2014, 15, 183-199

    In the last couple of decades several drug carriers have been tailored on the nanometric scale by taking advantage of new stimuli responsive materials. Thermoresponsive polymers in particular have been extensively employed as stimuli-responsive building blocks that in combination with other environmental-responsive materials allowed the birth of smarter systems that can respond to more than one stimulus. Examples that highlight the different polymers for thermally triggered drug delivery will be described. A special emphasis will be given to the description of novel theranostic nanodevices that combine more than one responsive modality in order to create a local hyperthermia that leads to the polymer phase transition and triggered drug release, cell recognition, and/or appearance of an imaging signal.
  12. One-step Chemoselective Conversion of Tetrahydropyranyl Ethers to Silyl-Protected Alcohols
    J. Bergueiro, J. Montenegro,* C. Saa and S. Lopez*
    RSC Advances
    2014, 4, 14475-14479

    Aluminium trichloride catalyses the expeditious direct conversion of tetrahydropyranyl ethers to silyl ethers. This one-step transformation is chemoselective versus deprotection of the acetal and hydrosilylation of unsaturated carbon–carbon bonds, and can also be applied to linear acetals. A possible mechanism is tentatively proposed.
  13. The ON/OFF Switching by Metal Ions of the “Sergeants and Soldiers” Chiral Amplification Effect on Helical Poly(phenylacetylene)s
    J. Bergueiro
    , F. Freire, E. P. Wendler, J. M. Seco, E. Quiñoa and R. Riguera*
    Chem. Sci. 2014, 5, 2170-2176

    Here we report copolymers where the “Sergeants and Soldiers effect” can be switched ON and OFF by the presence of a metal ion. These copolymers have been prepared by a combination of achiral and chiral monomer units, where the chiral ones are unable to drive the chiral amplification unless a small amount of mono- or divalent metal ions is added. In this way, the ions act as promoters upgrading some of the chiral pendants, initially unable to induce a preferential helical sense, to a higher rank forcing the arrangement of the rest of the chain in a specific helical sense. In these copolymers, the classical “Sergeant” and “Soldier” roles are modified in such a way that the chiral units become “Sergeants” only by the effect of an achiral external stimulus, namely the metal ion. The structure of the metal complex determines its interaction in the helix with the surrounding chiral and achiral “Soldiers” and therefore also determines both the intensity of the amplification and the response of a copolymer to a certain metal. For instance, poly(1r-co-7(1−r)) shows chiral amplification (“Sergeants and Soldiers effect”) towards the right-handed helix only with divalent ions, while poly(1r-co-8(1−r)) amplifies the helix to the left-handed sense with mono- and to the right-handed sense with divalent ions. This behaviour allows, using a single copolymer, to selectively induce any of the two helical senses. The aggregation and encapsulation properties of these copolymers are also described.

    Inside Front Cover

    Highlighted in NanoWerk

  14. Encyclopedia of Toxicology 3rd 2104 Ed. Chapter: “Silane” (Elsevier Ed.) pp 261-263
    S. López, J. Bergueiro and J. Fidalgo
  15. Encyclopedia of Toxicology 3rd 2014 Ed. Chapters: “Silicon Tetrachloride” (Elsevier Ed.) pp 916-918
    S. López, J. Bergueiro and J. Fidalgo
  16. Synthesis of 11-cis-Retinoids by Hydrosilylation-Protodesilylation of an 11,12-Didehydro Precursor. Easy Access to 11- and 12-Mono and 11,12-Dideuteroretinoids
    J. Bergueiro, J. Montenegro, C. Saá and S. López*
    Chem. Eur. J. 2012, 18, 14100-14107

    Reduction to retinoids: An expeditious approach to 11-cis-retinoids was achieved on the basis of semireduction of a readily available 11-yne precursor through a highly efficient hydrosilylation–protodesilylation protocol (see scheme). The complete selectivity of the method also allowed direct access to 11- and 12-mono-, and 11,12-dideutero-11-cis-retinoids.
  17. 1-{[1-(Cyano-2-ethoxy-2-oxoethylidenaminooxy)dimethylaminomorpholino-methylene]}methaneaminium Hexafluorophosphate (COMU)
    J. Bergueiro
    Synlett 2012, 23, 1849
  18. Cross-coupling Reactions of Organosilicon Compounds in the Stereospecific Synthesis of Retinoids
    J. Bergueiro, J. Montenegro, F. Cambeiro, C. Saá and S. López*
    Chem. Eur. J. 2012, 18, 4401-4410

    Silicon does it better! A comprehensive study of dienylsilane cross-coupling establishes the most efficient route yet reported to all-trans and 11-cis-retinoids. The key Hiyama reaction is superior to other couplings in terms of the overall yield, the stability and unproblematic handling of the metallic intermediates and the mild, ecologically preferable reaction conditions (see scheme).
  19. Hiyama Cross-Coupling Reaction in the Stereospecific Synthesis of Retinoids
    J. Montenegro, J. Bergueiro, C. Saá and S. López*
    Org. Lett. 2009, 11, 141-144
The first application of the Hiyama reaction to the synthesis of retinoids is reported. A range of organosilicon moieties (siloxanes, silanols and three kinds of “safety-catch” silanols) were successfully coupled, under activation, to obtain trans-retinol or 11-cis-retinol with high yield and stereoselectivity. The advantageous properties of the silicon-based coupling partners and the mild reaction conditions firmly establish the Hiyama reaction as a viable (even superior) alternative to the traditional Suzuki and Stille couplings in the retinoid field.