1. |
Pierini F., Guglielmelli A.♦, Urbanek O., Nakielski P., Pezzi L.♦, Buda R.♦, Lanzi M.♦, Kowalewski T.A., De Sio L.♦, Thermoplasmonic‐activated hydrogel based dynamic light attenuator,
Advanced Optical Materials, ISSN: 2195-1071, DOI: 10.1002/adom.202000324, Vol.8, No.12, pp.2000324-1-7, 2020Abstract: This work describes the morphological, optical, and thermo‐optical properties of a temperature‐sensitive hydrogel poly(N‐isopropylacrylamide‐co‐N‐isopropylmethacrylamide) [P(NIPAm‐co‐NIPMAm]) film containing a specific amount of gold nanorods (GNRs). The light‐induced thermoplasmonic heating of GNRs is used to control the optical scattering of an initially transparent hydrogel film. A hydrated P(NIPAm‐co‐NIPMAm) film is optically clear at room temperature. When heated to temperatures over 37 °C via light irradiation with a resonant source (λ = 810 nm) to the GNRs, a reversible phase transition from a swollen hydrated state to a shrunken dehydrated state occurs. This phenomenon causes a drastic and reversible change in the optical transparency from a clear to an opaque state. A significant red shift (≈30 nm) of the longitudinal band can also be seen due to an increased average refractive index surrounding the GNRs. This change is in agreement with an ad hoc theoretical model which uses a modified Gans theory for ellipsoidal nanoparticles. Morphological analysis of the composite film shows the presence of well‐isolated and randomly dispersed GNRs. Thermo‐optical experiments demonstrate an all‐optically controlled light attenuator (65% contrast ratio) which can be easily integrated in several modern optical applications such as smart windows and light‐responsive optical attenuators. Keywords: active plasmonics, gold nanorods, hydrogels, optical attenuators, optical transparency, plasmonic nanoparticles, polymers Affiliations:
Pierini F. | - | IPPT PAN | Guglielmelli A. | - | University of Calabria (IT) | Urbanek O. | - | IPPT PAN | Nakielski P. | - | IPPT PAN | Pezzi L. | - | other affiliation | Buda R. | - | Institute of Physical Chemistry, Polish Academy of Sciences (PL) | Lanzi M. | - | University of Bologna (IT) | Kowalewski T.A. | - | IPPT PAN | De Sio L. | - | Sapienza University of Rome (IT) |
| |
2. |
Rinoldi C.♦, Costantini M.♦, Kijeńska-Gawrońska E.♦, Testa S.♦, Fornetti E.♦, Heljak M.♦, Ćwiklińska M.♦, Buda R.♦, Baldi J.♦, Cannata S.♦, Guzowski J.♦, Gargioli C.♦, Khademhosseini A.♦, Święszkowski W.♦, Tendon tissue engineering: effects of mechanical and biochemical stimulation on stem cell alignment on cell‐laden hydrogel yarns,
ADVANCED HEALTHCARE MATERIALS, ISSN: 2192-2659, DOI: 10.1002/adhm.201801218, Vol.8, No.7, pp.1801218-1-10, 2019Abstract: Fiber-based approaches hold great promise for tendon tissue engineering enabling the possibility of manufacturing aligned hydrogel filaments that can guide collagen fiber orientation, thereby providing a biomimetic micro-environment for cell attachment, orientation, migration, and proliferation. In this study, a 3D system composed of cell-laden, highly aligned hydrogel yarns is designed and obtained via wet spinning in order to reproduce the morphology and structure of tendon fascicles. A bioink composed of alginate and gelatin methacryloyl (GelMA) is optimized for spinning and loaded with human bone morrow mesenchymal stem cells (hBM-MSCs). The produced scaffolds are subjected to mechanical stretching to recapitulate the strains occurring in native tendon tissue. Stem cell differentiation is promoted by addition of bone morphogenetic protein 12 (BMP-12) in the culture medium. The aligned orientation of the fibers combined with mechanical stimulation results in highly preferential longitudinal cell orientation and demonstrates enhanced collagen type I and III expression. Additionally, the combination of biochemical and mechanical stimulations promotes the expression of specific tenogenic markers, signatures of efficient cell differentiation towards tendon. The obtained results suggest that the proposed 3D cell-laden aligned system can be used for engineering of scaffolds for tendon regeneration. Keywords: hydrogel fibers, static mechanical stretching, stem cell alignment, tenogenic differentiation, wet spinning Affiliations:
Rinoldi C. | - | other affiliation | Costantini M. | - | Sapienza University of Rome (IT) | Kijeńska-Gawrońska E. | - | Warsaw University of Technology (PL) | Testa S. | - | Tor Vergata Rome University (IT) | Fornetti E. | - | Tor Vergata Rome University (IT) | Heljak M. | - | Warsaw University of Technology (PL) | Ćwiklińska M. | - | Institute of Physical Chemistry, Polish Academy of Sciences (PL) | Buda R. | - | Institute of Physical Chemistry, Polish Academy of Sciences (PL) | Baldi J. | - | Tor Vergata Rome University (IT) | Cannata S. | - | Tor Vergata Rome University (IT) | Guzowski J. | - | Institute of Physical Chemistry, Polish Academy of Sciences (PL) | Gargioli C. | - | Tor Vergata Rome University (IT) | Khademhosseini A. | - | Massachusetts Institute of Technology (US) | Święszkowski W. | - | other affiliation |
| |